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History of Orthodontics

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History of Orthodontics

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A glance at an exciting path, the oldest specialty of dentistry has treaded so far…

Basavaraj Subhashchandra Phulari BDS MDS FAGE FRSH

Formerly Faculty, Department of Orthodontics and Dentofacial Orthopedics Mauras College of Dentistry, Hospital and Oral Research Institute Republic of Mauritius

Foreword

US Krishna Nayak

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Website: www.jaypeebrothers.com Website: www.jaypeedigital.com © 2013, Jaypee Brothers Medical Publishers All rights reserved. No part of this book may be reproduced in any form or by any means without the prior permission of the publisher. Inquiries for bulk sales may be solicited at: [email protected] This book has been published in good faith that the contents provided by the author contained herein are original, and is intended for educational purposes only. While every effort is made to ensure accuracy of information, the publisher and the author specifically disclaim any damage, liability, or loss incurred, directly or indirectly, from the use or application of any of the contents of this work. If not specifically stated, all figures and tables are courtesy of the author. Where appropriate, the readers should consult with a specialist or contact the manufacturer of the drug or device. History of Orthodontics (A glance at an exciting path, the oldest specialty of dentistry has treaded so far…) First Edition: 2013 ISBN 978-93-5090-471-8 Printed at

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Dedicated to My Dear Parents Subhashchandra and Shivalingamma Phulari My Brothers Sangamesh BE (USA), Jagadish BE (USA) and Manjunath BE (USA) My Beloved Wife Dr Rashmi GS, Reader (Oral Pathology) and My Sons Yashas and Vrishank

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Foreword Humanity is passing through the most exciting period in the history of its existence, because of rapid technological advancement and increase in the research activities, there has been an enormous increase in the information available which has led to better understanding of the respective subjects and areas of specialization. With the contemporary understanding of orthodontics, it is more apt and important for everyone involved in the subject to be aware of how our forefathers in the subject thought, how the subject evolved in different countries, how new concepts evolved providing a trigger to each and everyone to explore deeper into the subject and make learning more exciting and enjoyable. Dr Basavaraj Subhashchandra Phulari has made sincere efforts to go into the depth of each topic providing an exhaustive insight. I am convinced that it will be a great learning experience for all the readers.

US Krishna Nayak BDS MDS (Ortho) FFPA FICD FADI FWFO

Dean Academics, AB Shetty Memorial Institute of Dental Sciences Karnataka, India Past President, Indian Orthodontic Society Past President, Indian Dental Association Head Office Chairman, 8th Asia-Pacific Orthodontic Congress and 47th IOC New Delhi, India Chairman, 17th IOS PG Convention-2013 Editor, Asia Pacific, HEAL TALK-A Journal of Clinical Dentistry President Elect, International College of Dentists (India, Sri Lanka and Nepal Section) Secretary, International College of Continuing Dental Education (India Section). Immediate Past Chairman, Pierre Fauchard Academy (India Section)

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Preface

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Knowledge and understanding of the history of a scientific field can enable future practioners of that field better to anticipate and respond to the challenges of rapid globalization and be better prepared to mold our future. Exposure to the history of our specialty helps us think, ask question and explore the concepts and enable us to grasp what the subject is about and how it has evolved over the years. History of Orthodontics is interesting and same time it is complex. This book is an attempt to glance and take a note of important milestones in the exciting journey of this fascinating field. It is hoped that the book would be useful to all the students of the faculty. Extensive coverage of important events in the history of orthodontics that shaped what it is today. Separate chapters dedicated to eminent inventors of the field—EH Angle, LF Andrew, James McNamara and TM Graber. Evolution of recent advances in orthodontics such as Invisalign and dental lasers are included. Evolution of orthodontic materials, model analysis, cephalometrics and orthodontic appliances are included. Exhaustive list of references is given for further reading.

Basavaraj Subhashchandra Phulari [email protected]

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Acknowledgments Writing history of the oldest specialty of dentistry and as fascinating as orthodontics at that, was a herculean task. For writing history of any field, even it requires the author/historian to be present at that specific time and place of the event that has taken place, which is practically not possible. An event of today becomes history tomorrow. As we unravel and cherish the history of yesteryears, a new history would be shaping today. In the light of this practicality, I do agree that none of the chapters in the book is directly written by me. I have drawn generously from the existing literature about the subject in the form of various books, journal articles, research papers and thesis, etc. In many of the chapters, literature about a specific event or person/researcher is kept as it appears in its original literature so as to maintain authenticity and also not to inadvertently twist the history. Many of the illustrations of the orthodontic appliances and photographs of eminent researchers used in this book are facsimiles of the pictures that appear in the existing literature about the subject. I hereby humbly acknowledge all the authors of various orthodontic books, articles, thesis, seminars, etc., whose works inspired the birth of this project. The list of the literature used for the preparation of this project is given at the end of the book under the heading of suggested reading. I also gratefully acknowledge all the professors, teachers and postgraduate students of the faculty from various dental institutions in India and abroad who have contributed directly or indirectly to this exhaustive piece of work. My special thanks to my beloved wife, Dr Rashmi GS, Reader and Postgraduate Guide, Department of Oral Pathology, Manubhai Patel Dental College and Hospital and Oral Research Institute, Vadodara, Gujarat, India, for her valuable critical comments during the preparation of the manuscript, editorial assistance and proofreading. I take this wonderful opportunity to thank Dr Rajendrasinh Rathore, Chairman of Manubhai Patel Dental College and Hospital and Oral Research Institute, Vadodara, for his inspirational support during this endeavor and throughout my career. I also thank Dr Yashraj Rathore, Trustee, Manubhai Patel Dental College and Hospital and Oral Research Institute, Vadodara, for encouraging me during this project. I owe a debt of gratitude to Professor (Dr) US Krishna Nayak, Dean Academics, AB Shetty Memorial Institute of Dental Sciences, Mangalore, Karnataka, India, for his continuous encouragement in all my endeavors and for providing foreword to this book. I am indebted to Dr Anil Shah for all the help and encouragement I have received from him during the formation of the Chapter 7—History of Dental Lasers and their Applications in Orthodontics in the book. I extend my heartfelt gratitude to Dr Padmaja Ankit Arora for helping me with important references that were required for writing the chapters on TM Graber, James McNamara and Invisalign. My heartfelt gratitude goes to Dr Poorya Naik, Assistant Professor, College of Dental Sciences, Davengere, Karnataka, Dr Ramesh GC, Assistant Professor, Sharavati Dental College, Shimoga, Karnataka, and Dr Sujay J, Assistant Professor, SJM Dental College, Chitradurga, Karnataka, who have helped immensely in this endeavor. Exceptional efforts made the production of this book possible. I extend my special thanks to Dr Hina Desai for comments and suggestions regarding chapter on Dr TM Graber’s Contribution to Orthodontics.

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History of Orthodontics

I will be failing in my duty if I do not mention the affection and support I have received from Dr Syed Zakaullah, Chairman, Al Badar Dental College and Hospital, Gulbarga, Karnataka, who has always provided that moral boost much needed during compilation of this book. My heartfelt gratitude goes to Shri Jitendar P Vij (Group Chairman), Mr Ankit Vij (Managing Director) and Mr Tarun Duneja (Director-Publishing) of M/s Jaypee Brothers Medical Publishers (P) Ltd, New Delhi, India, whose exceptional efforts made the production of this book possible. I gratefully acknowledge the contributions made by the talented professional staff at M/s Jaypee Brothers Medical Publishers; in particular, I would like to thank Mr Venugopal V, Mr KK Raman and Mr Rajesh Sharma, for their untiring efforts in ensuring that every minute detail is taken care of. I am indebted to my dear parents for all their love and sacrifices that have made me what I am. I thank my dear sons Yashas and Vrishank for being the constant source of inspiration to set and reach new goals in life.

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Most of all, I thank God for all the kindness and mercy showered upon me.

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Contents 1. History of Dentistry Ancient Dentistry Dentistry During the Middle Ages Dentistry in the Sixteenth and Seventeenth Centuries Dentistry in the Eighteenth Century

1 2 6 7 10

2. Introduction to Orthodontics Definition of Orthodontics What is Malocclusion? Aims of Orthodontic Treatment Branches of Orthodontics Orthodontic Appliances Timing of Orthodontic Intervention Scope of Orthodontics Benefits of Orthodontic Treatment

14 14 15 15 16 17 18 18 19

3. History of Orthodontics from Ancient Civilization to Twentieth Century Ancient Civilization Middle Ages through Seventeenth Century Eighteenth Century Nineteenth Century Twentieth Century

20 20 21 22 23 24

4. History of Orthodontics in United States of America Norman Williams Kingsley (1829–1913)

28 31

5. History of Orthodontics in Great Britain The British Society for the Study of Orthodontics

34 37

6. History of Orthodontics in Greece and Rome Middle Ages (Fifth to Fifteenth Centuries) to the Eighteenth Century European Pioneers of the Early Nineteenth Century

44 44 45

7. History of Dental Lasers and their Applications in Orthodontics All Laser Devices Properties of Laser Beam Focused Versus Defocused Beam Types of Laser Lasers and their Dental Applications Current Clinical Use of Dental Lasers Laser Use in Dentistry Laser Classification Applications of Lasers in Orthodontics Laser Safety Precautionary Measures

47 47 48 48 49 50 51 51 52 53 58 58

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History of Orthodontics

8. Angle’s Contribution to the Faculty of Orthodontics Edward Hartley Angle—Dental Graduation Angle‘s Dental Practice at Towanda Edward Hartley Angle’s Professional Teaching Career Edward Hartley Angle‘s School of Orthodontics Appliance Contribution by Edward H Angle Angle’s Orthodontic Material Invention Case-Angle Controversy Criticisms

59 60 60 61 65 66 69 70 71

9. Dr TM Graber’s Contribution to Orthodontics Thomas M Graber (1917–2007) TM Graber’s Contributions Graber’s Other Contributions to Orthodontics

76 76 77 85

10. James McNamara’s Contribution to Orthodontics James McNamara Analysis Relating the Maxilla to the Cranial Base Relating the Mandible to the Maxilla (Midface) Relating the Mandible to the Cranial Base Dentition Analysis Airway Analysis Studies on Functional Appliances Studies on Rapid Maxillary Expansion Studies on TMJ

88 88 89 89 91 91 92 93 95 96

11. Andrews’ Straight Wire Appliance Why “Straight Wire”? Variable Bracket Sitting Procedures: Lawrence F Andrew’s Remedy Straight Wire Appliance Brackets for Different Clinical Situations Straight Wire Appliance (SWA)

98 100 102 102 103

12. Evolution of Orthodontic Appliances Brackets and Bands Archwires Properties of Archwire Auxiliaries History of Orthodontic Materials

106 107 114 117 119 120

13. History of Model Analysis Carey’s Analysis Pont’s Index Linderharth Index Korkhaus’ Analysis Howe’s Analysis—1954 Bolton’s Analysis Cast Analysis: Symmetry and Space Alignment (Crowding), Space Analysis Arvey Peck, Sheldon Peck—1972 Huckaba’s Analysis Hixon and Old Father Method—1958

122 123 123 124 124 124 125 126 126 127 127 128

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Contents

xv

Marvin M Tanaka, Lystle E Johnston in 1974 Nance Analysis Total Space Analysis—1978 Wylie Kesling Model Analysis Martinek Analysis Suwannee Luppanapornlarp 3D Model Analysis

128 129 130 131 131 131 131 132

14. History of Cephalometrics History Prior to the Advent of Radiography Cephalometric Radiography Holly B Broadbent’s Contribution Other Important Contributions Cephalometric Analysis Evolution of Cephalometrics Patient Orientation X-ray Source Position Film Position and Enlargement Posteroanterior (Frontal) Cephalometry Steiner’s Analysis: Cecil C Steiner (1896–1989)

133 134 137 138 139 139 140 140 140 140 141 143

15. History of Extraction in Orthodontics Arch-Length Analyses Second Premolar Extraction Evolution of the Philosophy of Extraction in Conjunction with Orthodontic Therapy Need for Extraction Choice of Teeth for Extraction Serial Extraction Historical Perspective Tweed’s Method (1966)

145 146 147 148 150 150 150 151 152

16. History of Expansion Appliances Wescott’s Expansion Device Angell’s Palatal Expansion Device Fixed Rapid Maxillary Expansion Appliances

154 154 154 156

17. History of Removable Orthodontic Appliances Development of Removable Orthodontic Appliances Components of Removable Orthodontic Appliance

160 161 162

18. History of Fixed Orthodontic Appliances E-Arch Appliance Pin and Tube Appliance Ribbon Arch Appliance Edgewise Appliance What was Orthodontics before Angle System? Evolution and Development of the Edgewise Appliance Evolution of Bracket Evolution of Edgewise Buccal Tubes The Concept of the Ideal Arch The Ideal Arch Wire

167 171 171 172 172 173 173 174 174 175 176

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History of Orthodontics

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Advantages and Disadvantages of Edgewise Appliance Building Treatment into the Edgewise Appliance Begg Appliance Straight Wire Appliance Andrews Six Keys to Optimal Occlusion Limitations of Straight Wire Appliance (SWA) Lingual Technique

178 178 179 180 180 182 183

19. History of Myofunctional Orthodontic Appliances Activator Frankel Appliance Bionator Class III or Reverse Bionator Oral Screen (Vestibular Screen) Herbst Appliance Twin-Block Appliance The Double Plate The Tooth Positioner

186 187 189 189 190 190 190 190 191 191

20. History of Surgical Orthodontics Pioneers Mandibular Procedures

193 195 196

21. History of Cleft Lip and Cleft Palate Demographic Data Embryological Aspects Classification Etiology of Cleft Lip and Palate Clinical Features Cleft Lip and Palate Associated Problems

197 199 200 200 201 202 203

22. History of Malocclusion Indices Index of Orthodontic Treatment Needs (IOTN) Peer Assessment Rating Index of Complexity, Outcome and Need Dental Aesthetic Index

205 218 219 220 221

23. History of Interproximal Enamel Reduction in Orthodontics History of Interproximal Enamel Reduction Indications Contraindications

223 223 224 225

24. History of Invisalign Historical Perspective of Invisalign What Exactly the Invisalign Means? Developing the Invisalign Brand Philosophy of Invisalign Fabrication of Invisalign Principle of Stereophotolithography Summary of the Invisalign Technique Indications of Invisalign Advantages of Invisalign

226 227 228 228 229 229 231 231 232 232

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Contents

Disadvantages of Invisalign Limitations of Invisalign Procedure of Treatment with the Invisalign Benefits of Invisalign Care of Teeth with Invisalign Study 1 Outcome Assessment of Invisalign and Traditional Orthodontic Treatment Compared with the American Board of Orthodontics Objective Grading System Study 2 How Well does Invisalign Work? A Prospective Clinical Study Evaluating the Efficacy of Tooth Movement with Invisalign Study 3 Retaining Alignment Changes with Invisalign Study 4 Structural Conformation and Leaching from In Vitro Aged and Retrieved Invisalign Appliances Study 5 Cytotoxicity and Estrogenicity of Invisalign Appliances Study 6 Color Fading of the Blue Compliance Indicator Encapsulated in Removable Clear Invisalign Teen Aligners Study 7 A Comparison of Treatment Impacts between Invisalign Aligner and Fixed Appliance Therapy during the First Week of Treatment Other Studies Scientific Studies

25. History of Molar Distalization in Orthodontics History of Molar Distalization Indications for Molar Distalization Contraindications of Molar Distalization An Ideal Intraoral Molar Distalization Appliance Mechanism of Action of Distalizing Appliances Pendulum Appliance Pend-X Appliance M-Pendulum Appliance Pendulum F Appliance Jones Jig Intermaxillary Class II Malocclusion Correction Appliances Vertical Holding Appliance Removable Molar Distalization Splint Symmetric Distalization with a TMA Transpalatal Arch Tube Plates for Distalization of Molars Cetlin Appliance Anchorage Need Extraoral Force The Force Applied The Lokar Appliance K-Loop Molar Distalizer The Distal Jet Appliance The Crozat Appliance

xvii 232 232 232 233 233 233 233 234 234 235 235 235 235 235 235 236 236 236 236 237 237

238 238 239 239 240 240 240 241 241 243 243 243 243 244 244 244 245 245 245 245 245 246 246 247

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History of Orthodontics

Molar Distalization by Magnets The Magnets The Klapper Superspring Herbst Appliance The Mandibular Anterior Repositioning Appliance (MARA) Saif Springs The ‘Fastback’ Appliance for Molar Distalization Features of Fast Back Appliance

247 248 248 248 249 249 249 250

Suggested Reading Index

251 259

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History of Dentistry

• Ancient Dentistry – I-Em-Hetep – Saracens – Prof George Ebers – Hwang-ti – Ya-tong – Aesculapius – Celius Aurelianus – Hippocrates – Galen – The Etruscans – Dr Guerini – Saint Apollonia – Marshall H Saville

• Dentistry during the Middle Ages – Abulcasis – Garriopontus – John Gaddesden – Guy de Chauliac – Giovanni Plateario • Dentistry in the Sixteenth and Seventeenth Centuries – Walter Herman Ryff – Andreas Vesalius – Gabrielus Fallopius – Bartholomeus Eustachius – Ambro’ise Pare – Johann Stephan Strobelberger

These seems to be little doubt that dentistry in some form has been practiced from the most ancient times, there seems to be but little doubt, since considerable fragmentary evidence still exists as to the general methods used by the ancients. If we stop to enquire who first extracted teeth, made plates or filled carious cavities we shall find that all such information is shrouded in the mists of antiquity along with the history of the pyramids and other relics of early civilization. Oral disease has been a problem for humans since the beginning of time. Skulls of the CroMagnon people, who inhabited the earth 25,000

– – – – – –

1

Nathaniel Highmore William Cowper James Drake Wilhelm Fabry Antoni Van Leeuwenhoek Matthias Gottfried Purmann

• Dentistry in the Eighteenth Century – Lorenz Heister – Johann Adolph Goritz – Pierre Fauchard – Bourdet – Thomas Berdmore – John Hunter – Robert Bunon

years ago, show evidence of tooth decay. The earliest recorded reference to oral disease is from a Sumerian text (circa 5,000 BC) that describes “tooth worms” as a cause of dental decay. Dentistry, as a part of the medical art, was first practiced by the priests as a sort of religious rite, but later material remedies were added to aid in effecting cures and help to maintain the prestige of the priesthood. Later the laity became interested, and surgery, including dentistry, was for a long period practiced by barbers and travelling charlatans, who resorted to music and various other forms of entertainment to attract the

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2

History of Orthodontics

people. Finally, a few of the more far-seeing medical and dental practitioners became convinced of the necessity for better educated men to practice this important speciality, and thus dentistry gradually rose from about the beginning of the sixteenth century from a desultory trade or calling to the dignity of a learned profession. However, not until the latter half of the nineteenth century and the first part of the twentieth century did it really make rapid progress. It is a notable fact that many worthy dentists of modern times began their career in the laboratory or office of older practitioners. Later, however, they added to this training such scientific knowledge as was obtainable at the time and reached an honorable position among professional men. Not until 1840 was a dental college organized to teach systematically the theory and practice of dental surgery. This, the Baltimore College of Dental Surgery, was chartered February 1, 1840, opened in that year, and is still in existence. Perhaps it is within the last thirty-two years that the greatest progress has been made by this young profession, during which time Dr Black (Fig. 1.1) introduced scientific cavity preparation and a balanced alloy, Drs. Callahan, Rhein, Best et al gave us scientific root-canal work, and Dr Taggart perfected and introduced the gold inlay, while silicate fillings have come to occupy an important place in operative work, and the Roentgen ray has become an indispensable aid in diagnosing pathological conditions. In 1910 Dr. William Hunter, of London, contributed his celebrated paper on the “Relation between Oral Infection and Systemic Disease,” and woke the dental profession to its responsibilities. Oral prophylaxis has progressed to a point where unclean mouths are no longer tolerated, and the prosthesis has come to our aid with removable bridge-work and more scientific methods of denture-making. ANCIENT DENTISTRY In the words of a distinguished writer, “To know the history of a profession is to know the profession itself.” It has also been said, “There is nothing new under the sun;” but be that as it may, it is a fact that

Fig. 1.1: GV Black

much that is considered new in medicine, dentistry and surgery was known to Hippocrates, Fauchard, Galen and Pare. Sacerdotal Medicine, which was practiced in remote times by the priesthood, was mostly derived from the false notion prevalent among primitive peoples that the afflicted person had been stricken by the wrath of some divinity. The priests were always ready to treat such cases, as they were well paid, and if the person recovered, their prestige was considerably increased, while if the patient did not improve it was because the supposed offender was not worthy of receiving the desired pardon. The first physician of record was I-Em-Hetep (“He who cometh in peace”), who lived in the region of King Tosher of the Third Dynasty of Egypt, about 4000 BC. He was evidently a man of great prominence, since the Egyptians constructed a pyramid at Sakkra in his honor, and as many statuary likenesses of him have been found, it is evident that after his death he was worshipped as the Egyptian God of Medicine. That the early Egyptian surgeons had to use great skill in the treatment of disease is proven by the oldest book in existence, called The Instruction of Path- Hetep. Ancient Egypt was the seat of culture and learning; many students were drawn there from other lands in search of knowledge, and we are told that during the time of Herod- Otus, about 500 BC, dentistry was practiced as a specialty, so

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History of Dentistry

that “Egypt is quite full of doctors: those for the eyes, those for the head, and some for the teeth, others for the belly or for occult maladies.” The Saracens invaded Egypt in the seventh century, and in 642 A.D., shamefully destroyed the great library at Alexandria. It is probable that much valuable literature pertaining to early medicine and dentistry was thus lost, among others the writings of Herophilus and Erasistratus, who, about 300 B.C., were pioneers in dissection not only of cadavers but of living men condemned to death by the kings of Egypt. Dental art among the ancient Egyptians is described at some length in the papyrus of Ebers a name derived from the material on which it is written (papyrus, a form of ancient parchment, or paper), and the discoverer, Prof George Ebers who found it at Thebes in 1872. This work, which dates from 3500 to 1500 BC, gives many remedies for toothache and the so-called “Benut blisters in the teeth.” These remedies consisted of dough, honey, oil, fennel seeds, incense, onions and similar ingredients used in various combinations, to be made into a plaster and applied to the aching tooth. One prescription consists of the following: It is evident that dentistry in some of its cruder forms must have come into being as soon as man began to experience trouble with his teeth. The teeth are likewise largely relied upon to furnish diagnostic evidence in determining whether prehistoric skulls found in excavating are of human or animal origin. Prehistoric teeth do not, as a rule, show evidence of caries, and if it be present it is said to be an evidence of considerable age, though it is difficult to understand the reason for this assumption, since caries is usually most prevalent among children. Signs of abrasion are quite common, owing to the food habits and long life of the subject. The oldest written account of a dental operation, other than extraction, is found in a statement by Archigenes, of Rome, who advocated the repining of a tooth which ached without there being evidence of caries, his idea being that the pain was caused by morbid material in the interior of the tooth, which by this means could be evacuated. Among the ancient Hebrews neither the Bible nor the Talmud makes any mention of dental operations, though the teeth and their beauties are often extolled. “An eye for an eye and a tooth

3

for a tooth” was a part of the law of the land, as, also, “If a man smite out one of his servant’s teeth he shall let him go free.” The Chinese boast a very ancient civilization, and it is not unlikely that dentistry in some of its cruder forms was known to them at a very early period in the world’s history. The Chinese “Father of Medicine,” was Hwang-ti, who lived about 2700 BC. The celebrated medical works of China refer to toothache, which is called “Ya-tong,” and describe nine varieties of this malady, and in addition there to seven distinct diseases of the gums. Puncturing the gums as well as distant parts of the body for the relief of toothache and abscesses was practiced, this being, perhaps, one of the oldest forms of dental or oral surgery. The same method of treatment, known as acupuncture, was applied to many other diseases as well and the Chinese doctors chose their points of election in a very scientific and learned manner, having altogether three hundred and eighty-eight sites for puncturing, twenty-six of which were for the relief of toothache. For this purpose they used gold, silver or steel needles and cauterized the site afterward with a cone of moxa, a sort of slowburning vegetable wool applied through a hole in a coin. The moxa is compact and burns slowly, drawing up the epidermis into a blister without violence or excessive heat. According to Dabry, the Chinese believed there were worms in the teeth, and among the remedies used therefore arsenic is said to have been made into pills, and one placed near the aching tooth or into the ear on the opposite side from the aching organ, whereupon the pain would positively cease. Another favorite prescription used by the Chinese read as follows: “Roast a bit of garlic and crush it between the teeth; mix with chopped horseradish seeds or saltpeter; make into a paste with human milk; form pills and introduce one into the nostril on the opposite side to where the pain is felt.” According to the Greeks, Aesculapius, the God of Medicine, is supposed to have been the son of Apollo. Cicero mentions three deities of this name, the third of which was said to be the son of Arsippus, who was the first to teach tooth-drawing and blood-letting. The instrument used for toothdrawing is supposed to have been the “odontagogon” of lead mentioned by Celius

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4

History of Orthodontics

Aurelianus and exhibited in the temple of Apollo at Delphi, sculapius, who was worshipped by the Greeks as one of their many Gods, was said to have healed the sick and to have raised the dead as well. As time elapsed there were reputed to be not only one, or, as related by Cicero, three sculapii, but tradition gave rise to many Gods of this name to whom numerous temples known as “Asklepeia” were erected, among which was the famous temple of Cos, where Hippocrates gained most of his knowledge of medicine. The priests or followers of Esculapius were known as “Asklepiadi.” To Hippocrates is accorded the honorable title of Father of Medicine, and even in those early days the “oath of Hippocrates” was a solemn obligation to be taken by all who undertook the study or practice of medicine. Hippocrates was born on the island of Cos about 460 BC and first studied medicine under his father, but later devoted his attention to the medical books in the temple of Cos. Hippocrates wrote much in regard to dental maladies and their remedial measures, among which were considered extraction and cauterization. He was the inventor of certain crude dental forceps and other dental instruments. He practiced the extraction of loose teeth and cauterization of those that ached but were not loose. He also recognized that the first teeth are formed before birth by the nourishment of the fetus in the womb. In speaking of fracture of the lower jaw, Hippocrates recommended binding the teeth next to the lesion together. He distinguished between the complete and the incomplete fractures and treated separately of fractures of the symphysis. If the teeth were loosened he advised binding several together on either side of the fracture until consolidation of the bone had taken place, using for this purpose either gold wire or linen thread. At this time lay medicine had begun to supplant sacerdotal medicine, and healing by the priests as a religious rite was slowly giving place to more scientific and rational methods. Galen, who lived about six hundred years after Hippocrates, was an able writer and commented on Hippocrates’s work. Galen was a noted anatomist, and although he classified the teeth as bones, he said they were unlike other bones. He was the first to recognize nerves (pulps) in the teeth, and also erroneously believed that the

teeth have something to do with the sense of taste. In his anatomical researches he recognized seven pairs of cranial nerves and classified the trigeminal as the third pair. He was also of the opinion that the teeth grow and thus repair the wear on them, basing his opinion on the fact, no doubt, that a tooth having no opponent became longer. In painful Dentition Galen advised rubbing the gums with the milk of a bitch or the brains of hare.” He was, in his day, one of the most famous medical men of Rome and the author of many works on medicine. By this time the doctors’ shops were well supplied with medicines, bandages and a great variety of instruments, showing that the medical art had made considerable advancement. Dentistry had not yet become a separate profession, but was practiced by the doctors along with medicine and surgery. The Etruscans, or early Italians inhabiting that part of Italy known as Etruria, between the Tiber and Arno, about 1000 to 200 BC, used bridges made of gold rings holding ox teeth, for the purpose of replacing lost dental organs. Just who these Etruscans or Toshi were, from whence they came or what became of them is not definitely known, and their language is equally extinct, no code having been discovered by which their writings can be deciphered. The Romans have also left us some specimens of bridge-work and other prosthetic appliances, which for the most part are found in tombs or in the urns containing the ashes of those cremated. It was said to be a custom to remove such pieces from the mouth before cremation and afterward place them in the urn with the ashes. According to the Law of the Twelve Tables, written in Rome about 450 BC, it was not unlawful to bury or burn corpses with the gold that was used to bind the teeth together. At this early period in the world’s history, Rome must have had dentists, though she had as yet no doctors. According to Dr. Guerini and others a gold crown is now in the museum of Pope Julius, in Rome, which was discovered in excavating at Satricum, near that city. This would tend to prove that the Etruscans not only did bridge-work, but were versed in the art of making crowns also. The appliance found at Satricum was made of two plates of gold

History of Dentistry

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stamped to represent the labial and lingual surfaces of the lower central incisor, and were then soldered together to form the crown of the tooth. It is soldered to a narrow strip of gold which is contoured in such manner as to encircle the neighboring teeth, which act as a support for the appliance. Saint Apollonia in the year 300 AD, was canonized by the Church of Rome, and since then has been the patron saint of dentistry. The ninth day of February has been observed by the Church of Rome in her commemoration. A photograph of the painting of this saint was, in 1900, presented to the Academy of Stomatology of Philadelphia, on behalf of Dr Mary H Stillwell, of Pittsburgh, by Dr C N Pierce, together with this historical sketch: “Longing to obtain the grace of baptism, she made her way to Saint Leonine, a disciple of St. Anthony of Egypt, and, as he baptized her, he bade her go to Alexandria and preach the faith. So she went forth, and though she was only a woman, young and frail, yet so eloquent were her words, so fervent her zeal, that she made many converts. About this time a tumult had been stirred up in the city against the Christians and the mass of the people were enraged at her teaching and came with bitter complaints to her father, who gave her up to be judged by the governor. They brought her before the idol temple and bade her worship the graven image. It is reported that she made a sign of the cross, and there came forth from the statue an evil spirit shrieking, ‘Apollonia has driven me hence!’ This was more than could be borne; the people thirsted for vengeance, so they tried by torture to overcome her constancy. She was bound and one by one her teeth were drawn out, but still she did not flinch or fear, and on her refusal to accede to the demands of her persecutors and renounce her faith, she was brutally clubbed about the head and face, and subsequently suffered death by fire. “For a period of nearly fifteen hundred years her intercession has been sought for relief from all pain incident to dental diseases, and her relics have been and are regarded as possessing great efficacy in the cure of the same.” Scribonius Largus, writing during the first century of the Christian era, was perhaps the first author to give rise to the belief that worms were

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the cause of pain and decay in the teeth. As we shall find later this superstition existed throughout the Middle Ages, and it was not until the early part of the eighteenth century that Fauchard first cast doubt on their existence. As a remedy for these worms, Scribonius Largus suggested that if the seeds of hyoscyamus (henbane) be burned on charcoal and the fumes inhaled they would cause the worms to fall from the teeth. It is a noteworthy fact that the seed buds of henbane, when burned, form an ash that much resembles worms, and as the drug has a narcotic effect that probably soothed and relieved the pain, it is no wonder that the ignorant populace of that time readily gave ear to such seemingly plausible humbug. Celius Aurelianus gave an account of the odontagogon of lead found in the temple of Apollo at Delphi, by which it was assumed that teeth should not be extracted unless loose enough to be removed with a leaden instrument, though some have contended that this was only a model placed there, probably by Esculapius, to be reproduced with an iron instrument by those wishing to copy it, lead being less affected by corrosion, and therefore more lasting. He also wrote on fractures and dislocation of the jaw, and described the methods to be used in their reduction. Celsus gave a prescription for producing sleep in persons afflicted with toothache. It contained acorns, castoreum, cinnamon, poppy, mandrake and pepper. When there was a large carious hollow in the tooth to be extracted, Celsus recommended that it should first be filled either with lint or lead, in order to prevent the tooth from breaking under the pressure of the instrument. It is not definitely known that he used fillings as a means of preserving the teeth or relieving toothache. Marshall H Saville, according to an article in the Bulletin of the Pan- American Union, reported the finding of teeth inlaid with gold, turquoise, rock crystal, red cement and other foreign substances in skulls of the aborigines who lived in various parts of North and South America. These teeth had been bored out with some tool and the filling skillfully placed in the cavity. This custom was quite common in Mexico, Central America and the province of Esmeraldas,

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History of Orthodontics

Ecuador. In this latter province he also secured an upper jaw from one of the natives which contained not only teeth inlaid with gold, but also a right lateral incisor which had been transplanted to replace a lost central incisor, showing that dentistry had reached a high stage of development as a means of ornamentation at least. He also discovered in an excavation at Copan a lower jaw with a left lateral incisor that had been carved from some dark stone and implanted to take the place of one that had been lost. In one case several teeth were found bound together with gold bands. There are in the Peabody Museum of Harvard University teeth in which had been placed inlays of jade, iron pyrites and gold, some of them arranged symmetrically in triangles, also banded inlays, all of which apparently were used for ornamentation (Dental Cosmos, 1916, Iviii, 281). Among Primitive People, even at the present time, some very peculiar customs prevail which have, no doubt, been a heritage from ancient times. Most of these people have beautiful strong teeth which they ornament and embellish in various ways for cosmetic or religious purposes, much to the detriment of these valuable organs. The substitution of gold teeth for missing ones has been practiced in Java from remote times, and among the natives in many parts of Asia and the Pacific Islands there is prevalent the custom of dyeing the teeth black. In Sumatra the women file their teeth down to the gums or into points, or partially remove the enamel, so as to be able to apply the dye. In Japan the married women dye their teeth black in order to distinguish them from the single women, using a dye that is made of urine, iron and a substance called “saki.” It is claimed that this dye is very durable and does not wear off for many years. Dr L Ottofy, in an article on “Dentistry in Japan,” says, “The practice of blackening teeth, as a symbol of the marital state, on the part of women is becoming obsolete, yet a number still continue the practice.” Formerly large quantities of black artificial porcelain teeth were exported from America to Japan, where artificial plates for men and single women were made with white teeth and those for married women with black teeth. There are on exhibition in the Army Medical Museum at Washington, D C, several sets of teeth of Japanese origin, carved from wood, that bear out the foregoing statement.

In Eastern India some of the people plane their teeth down to an even level and dye them red by masticating areca nuts. It is also said to be a custom in New South Wales for a young man to have his front teeth knocked out with a stone on reaching the age of virility, this being supposed to enhance his personal appearance. The natives of the Hawaiian Islands knock out their front teeth as a sacrifice to their god Eatoa. DENTISTRY DURING THE MIDDLE AGES Abulcasis (1050–1122), an Arabian author, who lived at Cordova, was one of the most able writers and surgeons of the Middle Ages. He wrote a treatise on medicine, entitled De Chirurgia, consisting of three volumes, the first of which was devoted entirely to the subject of cauterization, a form of treatment much practiced at that time. His method of performing this operation was to insert a red-hot cautery through a tube to protect the surrounding parts. He was especially interested at that early date in prophylaxis and devoted special attention to the tartar on the teeth, illustrating and describing fourteen forms of scrapers or sealers for its removal. He was a very religious and devout man, cautious in the treatment of his patients and firmly opposed to the needless extraction of teeth. When it became necessary to extract, he used one form of forceps to loosen the tooth and another for its removal. Elevators were used if the forceps failed or the tooth was broken. According to this author, replantation was extensively practiced and artificial substitutes were made of ox bone to replace teeth that had been lost. He advocated replanting teeth that had been removed by mistake or accident, holding them in place with ligatures of gold or silver wire until they had again become firm. Garriopontus, an Arabian writer, in 1045 AD, said: “On the island of Delphi a painful molar tooth, which was extracted by an inexperienced physician, occasioned the death of a philosopher, for the marrow of the tooth, which originates from the brain, ran down into the lungs and killed that philosopher.” For all we know this is the first record of a death resulting from the extraction of a tooth. John Gaddesden (1400–1450), an English doctor at Oxford, stated that dried cows’ dung or the fat of a green frog would positively cause teeth to fall out when applied to them, and said, “If an ox, peradventure, chewed a little frog with the grass,

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its teeth would fall out on the spot”. He is also authority for the statement that “The brains of a hare rubbed on the gums not only facilitate dentition but will make teeth grow again where they have been lost”. All of these remedies were recommended and employed by many later writers, who claimed to have performed marvellous cures by such absurd treatment. Such statements as the foregoing seem ridiculous to us, as anyone could have easily satisfied himself of their falsity. The application of the cautery or arsenical compounds must have met with some success, as the latter is known to produce extensive necrosis. Guy de Chauliac (1300–1368) was the most noted surgeon of the Middle Ages. He and others of that period wrote extensively of dental ailments and operations for their relief by both physicians and barbers. Guy followed in the foot-steps of the Arabians, who had made considerable progress before him, and referred explicitly to dentators and their instruments, thus beginning the recognition of dentistry as a specialty of medicine. He advised that dental operations be performed for greater security under the supervision of doctors, but had no criticism to make of dentators. This learned doctor used camphor, sulphur, myrrh and asafcetida as a filling material for carious cavities, and, like his predecessors, lent belief to the superstitious idea of worms in the teeth. It is uncertain whether the worms referred to by him were particles of decaying food, nerves, larvae of insects or the burning henbane seed, as previously referred to, but the accepted belief was that they were responsible for the pain in odontalgia. Fumigations with seeds of leek, onion and henbane mixed with goats’ tallow were resorted to in order to drive out the worms, after the manner first described by Scribonius Largus. Guy de Chauliac also refers to medicines which send the patient to sleep, among which are decoctions of opium, hyoscyamus and lettuce. A new sponge was soaked in these medicines and then dried, and when sleep was to be produced it was wet and applied to the patient’s nostrils. This form of anesthesia must have been very effective, for it is related that it was used for surgical operations, amputations actually being performed in this manner. To awaken the patient from this deep slumber, another sponge was wet with

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vinegar and applied, or the juice of the rue fennel was placed in the patient’s nostrils. This fact is of great importance, as it marks the first step in general anesthesia and antedates Horace Wells’s discovery by five hundred years, though it is doubtful if this old method was ever used extensively. This author is the first to cast doubt on the efficacy of the fat of green frogs for the purpose of causing the teeth to fall out. Superstition being uppermost in the lives of the people in those days, it took considerable courage to contradict the old authorities on such a wellestablished belief. In 1308, the barbers and surgeons of London were incorporated into one guild and the name of barber-surgeon was used to denote practitioners in all branches of surgery. This arrangement lasted until 1745 before it was finally dissolved, after which the barbers were only allowed to extract teeth. This should give one a fair conception of the low repute into which surgery had fallen during that period. The title of Doctor was first bestowed by the universities during the twelfth century and was used to denote a learned man in any profession. The title of Doctor of Medicine was first bestowed on William Gordenia by the College at Asti, in Italy, in 1329. Whether this title was earned or honorary is not known. The title of Surgeon Dentist was first given to Gillies and several other men in France in 1622, though the title was not fully established for many years afterward. Giovanni Plateario (1450–1525), a professor at Pisa, was the first dentist to use the sitting posture for performing operations on the teeth, others before him having used the horizontal position. The prevailing custom was to let the patient lie prone on ground and to hold his head between operator’s knees with a vise-like grip. DENTISTRY IN THE SIXTEENTH AND SEVENTEENTH CENTURIES Dentistry, with the other arts and sciences, made its most notable advancement as a learned profession during the sixteenth century, for it was about this time that the world as we know it, made its first rapid strides forward. The invention of the printing press in 1436, the taking of Constantinople by the Turks in 1453 and the discovery of America in 1492 all led to much

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History of Orthodontics

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migration of peoples and the dissemination of knowledge, which constituted the beginning of a new era in which dentistry had its part. In Germany, dentistry had been practiced for many centuries, as shown by artificial teeth in the urns of those who had been cremated, and at this time the Germans had made considerable progress. Here, as elsewhere, medicine was first practiced as a religious rite combined with witchcraft and empirical remedies. As early as 1460 Heinrich von Pfolsprundt wrote a book on medicine and surgery in which he described wounds and fractures and the mode of their treatment. Pains of the teeth and gums were treated by him by the use of beverages, showing his lack of skill in that direction. Walter Herman Ryff (died 1570) wrote the first book which treated of dentistry independently of medicine in 1548. He is conspicuous for the fact that his book was written in German, a living tongue, instead of the customary Latin, so that he may be looked upon as the first who attempted to diffuse useful medical knowledge among the common people. One of the most interesting things about his writings is that he is the first author to recognize the relation between diseases of the eyes and teeth, declaring that because of their intimate relation, neither can be healthy without the other being so too. While this reasoning is clearly wrong in the light of our present knowledge, it nevertheless marks a step in the right direction. According to Ryff the principal causes of dental diseases are heat, cold, traumatism and the gathering of humors, and he says “The most atrocious pain is when an apostema ripens in the root”. Andreas Vesalius (1514–1564), who at the early age of twenty-five years became famous as an anatomist, was the first who dared to correct the errors in Galen’s work, and gave a much more accurate description of the anatomy of the teeth than that given by Galen. His researches in regard to the teeth are incomplete, since he states that the permanent teeth grow from the roots of the temporary teeth. This erroneous conclusion was due to the fact, no doubt, that the deciduous teeth have no roots when shed. Gabrielus Fallopius (1523–1562), a pupil of Vesalius, carried out more fully his investigations

of the development of the teeth and corrected Vesalius’ error by showing that the permanent teeth do not grow from the roots of the temporary teeth, but that they are generated twice over, the first time in the uterus. He gave the first account of the dental follicle, and likened the teeth in their formation to the feathers of a bird ( De Dentibus Libellus, Venice, 1563). Bartholomeus Eustachius (died in 1574) was another great anatomist of the sixteenth century. After long and patient research he brought much light to bear on the macroscopic (gross) anatomy of the teeth, the number and variations of the roots, the alveoli, etc,. and gave a very clear description of the ligaments of the teeth and the means by which they are held in the alveolus. He also gave an account of the central cavity of the tooth, and stated that it contains blood- vessels and nerves, and not marrow, as was claimed by some anatomists. He also investigated the embryology of the teeth and confirmed the claim of Hippocrates that the first teeth are formed in the uterus. Eustachius is the first to deny that the teeth grow during a whole lifetime, as was first claimed by Aristotle. Speaking of dental diseases, this author remarked that dental surgery was in his days a most abject calling, notwithstanding its having had as its initiator no less a person than Aesculapius, the God of Medicine. Ambro’ise Pare, born in France (1517–1592), is justly entitled to the credit of being known as the “Father of Modern Surgery.” As an anatomist he is less accurate than either Vesalius or Eustachius, but as a surgeon he gained great renown, having been successively a barber, surgeon- barber, and finally, in 1562, chief surgeon to the court. In his works this surgeon treated of dental maladies very thoroughly, which fact may be attributed to his having first been a barber and consequently a tooth-puller. He described fractures of the jaw and the methods of their reduction with considerable thoroughness, and related some interesting cases which he had treated. In one instance a friend of his had his jaw broken and three teeth knocked out by a blow from a dagger, whereupon Pare so skillfully treated the injury that all the teeth were successfully replaced and made of use. The Golden Tooth, in 1593 much was said in Germany of a Silesian child, aged seven years, in whose mouth a golden tooth had erupted. Great

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credence was given to this story and the learned doctors and philosophers speculated upon the phenomenon without the slightest doubt as to its genuineness. Many books and papers were written to explain the strange occurrence, and one writer, Jacob Horst, claimed that on the date of the child’s birth, that is, December 22, 1585, the Sun was in conjunction with Saturn in the sign of Aries, and in consequence the nutritive force had developed so much that instead of osseous substance, golden matter had been secreted. It appears that the golden tooth was nothing more than a crown or lamina of gold let down deep into the gum, and made by a dentist or jeweler for the purpose of deception, since a fee was charged for seeing the child. Balthasar Camindus, a doctor of Frankfort, had noted that the boy had not lent himself to being examined by the learned, who were likely to expose the fraud, and further relates that a certain nobleman, being denied the privilege of seeing the tooth, struck a dagger into the boy’s mouth and wounded him so badly that a surgeon was called and the fraud exposed. In the early part of the seventeenth century the dental art was still in a pitiful state of development, as shown by the literature on the subject, only about twenty publications having appeared in Europe during the preceding century. Johann Stephan Strobelberger, physician to the Imperial Baths at Carlsbad, published a book in 1630 in which he referred to “Gout in the teeth”, which included all of the diseased humors of the teeth that were supposed to fall by drops into the articular cavities and surrounding parts. In his writings we find that many crude and worthless remedies were still used for toothache, and the instruments for extraction consisted for the most part of the pelican, named from its likeness to the beak of that bird, and also some very rude forceps. He was one of the first to cast doubt on the value of fumigations with hyoscyamus seeds to cause worms to fall from the teeth, though he did not in the least doubt the existence of the worms themselves, suggesting oil of vitriol or a decoction made of a frog cooked in vinegar to kill them instead. Among the remedies he suggested for odontalgia is the American tobacco plant (Nicotiana tabacum). Nathaniel Highmore (1613–1684) (published a treatise on anatomy in 1651, in which for the first

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time the maxillary sinus named for him is accurately described), though its existence had long been known. He pointed out for the first time the anatomical relation between the teeth and antrum, and related a most amusing incident in connection with perforation of this sinus. A lady, having much pain in her teeth finally had the upper canine tooth extracted, after which there was an incessant flow of humors (pus) from the antrum. The patient herself wishing to learn the cause thereof passed a silver probe into the cavity its entire length, which produced the effect of its having reached the eye. Much amazed she stripped a long feather and passed it into it so great a distance that she concluded that it had reached her brain, not knowing that the feather simply curled up in the cavity. He was able to allay her fears by informing her of the cavity in the bone and the opening produced by the extraction of the canine tooth. William Cowper (1666–1709) was the first to practise opening the antrum by the extraction of the first molar. This was toward the end of the seventeenth century, and he seems to be the first to recognize antral diseases. This was something like 50 years after Highmore had described the antrum. James Drake, a contemporary of Cowper, operated in the same manner, and it was this author who made known in a book entitled Anthropologia nova, published in 1707, the method of Cowper, for which reason the abovementioned proceeding is sometimes called the “Cowper-Drake operation.” Wilhelm Fabry, better known under the Latin name of Fabricius Hildanus (1560–1634), chief doctor to the city of Berne, gave some very interesting clinical reports on the relation between dental affections and tic douloureux, and cited an instance where a lady who had suffered atrociously for four years with pain in the head was completely cured by the extraction of four decayed teeth. He also gave an account of an interesting case of rhinoplasty performed by Dr J Griffon, an eminent surgeon of that day, upon a young girl of Geneva, whose nose had been cut off by the Duke of Savoy’s soldiers in a fit of rage. Fabry testifies to the natural appearance of the nose even for twenty years afterward. He stated

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that Gaspare Tagliacozzi, of the University of Bologna, was the inventor of this operation. Antoni Van Leeuwenhoek (1632–1723), a Dutchman, was the first to make high-powered microscopes with which, in 1678, he made discovery of the tubular structure of dentine, and in 1683 he discovered microorganisms in tartar scraped from between the teeth. From a perusal of his writings and drawings it appears that these bodies were bacteria rather than animalcules, as he supposed. Both Carpenter and Beal state that his work was done with single lenses, as the compound microscope did not reach a useful stage until about 1820 to 1830. It is astonishing how much was accomplished by such primitive means. This in all probability represents the first step in bacteriology, which was only made possible by the aid of high-powered lenses. Matthias Gottfried Purmann (1648–1721) has the honor of being the first writer to make mention of wax models in connection with prosthetic work. Whether these models were made from molds or not is a disputed question, but the supposition is that they were carved to the desired shape and then passed on to a craftsman who reproduced them in bone or ivory. Many other incidents of considerable interest during the seventeenth century have to be omitted in a history of this character, and consideration will now be given to the development of the eighteenth century. DENTISTRY IN THE EIGHTEENTH CENTURY In 1700, France took the lead in the dental art and had recognized the importance of dentistry by requiring prospective practitioners to take an examination under the edict of 1699 to show their qualifications before entering the profession. There is abundant evidence that the Germans had also made considerable progress during the two preceding Centuries and they have likewise left us considerable literature upon dental surgery. Dentistry had already begun to flourish as a distinct specialty of medicine, but it remained, as we shall see later, for Pierre Fauchard to effect the final separation. Lorenz Heister (1683–1758), of Frankfurt-amMain, published a treatise on dentistry entitled De Dentium Dolore in 1711, in which he advised

removing the decayed part of a tooth with a file or toothpick and filling the cavity with white wax, mastic or gold or lead-foil. In this work he gave a very concise description of removable prosthetic pieces made of ivory or hippopotamus tusks and maintained in position simply by their form. Heister also refers to nasal prosthesis, which was then carried out by applying noses of wood or silver, properly painted. There was at this time much contention among dentists as to the advisability of removing caries by the use of the file, as practised by Heister and others,because of the destruction of the enamel of the tooth. We find, however, that this was practised for a long period, and was advocated in a modified form by such eminent dentists as Drs. Chapin A. Harris and Robert Arthur more than a century later. Upto the eighteenth century the clumsy pelican or rude forceps, used to exert lateral force on the tooth, was still in general use, but this was modified about this time into what was known as the key of Garengeot, named after the man who perfected, though he did not invent, the instrument. According to some writers this instrument had its origin in Germany, not in England. It was a most efficient instrument for extracting teeth and was in general use for more than a century, having been extensively used in America, and is much used in France and other European countries at the present time. Johann Adolph Goritz, of Regensburg, writing in 1725, opposed too many extractions and also the insertion of prosthetic pieces, because they caused the loss of the teeth to which they were attached. This was due to their being wired to the natural teeth, causing great strain on and consequent loosening of the abutments. Pierre Fauchard (born in Brittany about 1690 and died in Paris in 1761) was the founder of modern dentistry. He published a work in 1728 entitled Le Chirurgien Dentiste, which marked a new epoch in the history of the dental art. This book was highly commended by the leading medical authorities of the day. It was translated into German in 1733, and a second revised French edition was issued in 1746, and a third in 1786. It consisted of two volumes in duodecimo, with 40 full-page plates, 863 pages in all, and treated of all branches of dentistry as understood and practiced at that time. According to Fauchard

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dentistry was then an important calling, as he refers to the examination which prospective practitioners were compelled to undergo even as early as 1700, and advises that a dentist be included in the board of examiners. He expressed himself in no uncertain terms as to the need of a school of surgery in which the theory and practice of dental surgery could be properly taught. Fauchard lamented that so little was written by able dentists who had preceded him, because these men guarded their knowledge with secrecy lest someone might profit at the author’s expense. It is a mistake to think that he created the art of dentistry, but that he placed it on a higher plane by many valuable inventions and by collecting and publishing all of the available knowledge on the subject, there is no doubt. To show how concisely he wrote, it may suffice to quote the following account of work that may be done on teeth : “They may be cleaned; they may be straightened; they may be made shorter; caries may be removed from them; they may be cauterized; they may be filled with lead; they may be separated; they may be placed in proper position; they may be fastened; they may be removed from the jaw; they may be replaced in the jaw; or they may be taken out to be placed in another person’s mouth; and at last teeth are artificially constructed, and may be placed instead of those that have been lost. All of these operations demand a skillful, steady and trained hand and a complete theory.” In this work he refers to the popular idea of worms in the teeth, which idea had existed for more than one thousand years. He admits the possibility of them, but states that he has never seen them, and that if they do exist they are not the cause of caries, but the eggs of insects may have entered carious cavities and there hatched and produced worms. Although Andry relates seeing very small worms with a powerful glass, Fauchard states that he employed the same means but could not see them. Thus he sets forever at rest this foolish superstition in regard to worms in the teeth as a cause of dental ailments so long indulged by the people of those times. Perhaps it is only as a matter of courtesy toward the many authors who preceded him that he admits their presence at all. Fauchard gave a very accurate description of the anatomy of the teeth, their structure, position,

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origin, growth and anatomical parts as, body, root and neck. He described accurately the pulp cavity and root canals, and after a most thorough macroscopic description, goes into the histology of the teeth, following the writings of La Hire in 1699. Fauchard agrees with the popular idea of his day in regard to caries, and states that it may have its origin within the tooth as well as without. From a passage in the fifth chapter of Fauchard’s work one learns that tooth-brushes were then already in use, but he says that those made of horsehair are too rough and frequently have a destructive action upon the teeth. He advised using small sponges, with which the teeth should be rubbed up and down, inside and outside, every morning. Before using the sponges they were to be dipped in tepid water or preferably aqua vitae, “the better to fortify the gums and render the teeth firm.” He was strong in his condemnation of elixirs and cures by magical means so much practised in his day, and a reference is made to the large and increasing number of Charlatans of the day, wherein he exclaimed, “There will shortly be more dentists than persons affected with dental diseases.” He laments over the poor quality of work done by them, relating a case where a deciduous tooth was extracted without roots, whereupon the dentist in an effort to extract the roots removed the permanent tooth just erupting. Fauchard advised seating the patient in an easy arm-chair for the purpose of performing dental operations, and condemned the practice of seating him on the ground or floor and holding his head between the operator’s knees, as was commonly done, as unskillful and unsanitary, and in the case of pregnant women, as capable of doing great harm. He practiced opening the tooth for relieving abscesses by evacuating the pus. After three months he stopped these teeth to prevent their getting worse, but no mention of root-canal work is made, though he placed a little cottonwool in the cavity with oil of cinnamon and allowed it to remain several weeks before filling them. Fauchard practiced orthodontia, and relates a case in which he used the file and pelican and put a crooked tooth in place, which operation required about ten minutes. The most difficult cases he states required from three to ten days,

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History of Orthodontics

and sometimes several months, to complete. He used gold and silver plates, which were perforated with holes through which he passed a silk thread for correcting irregularities, and when this was not sufficient he forced them in place with the pelican or forceps. In 1737, Fauchard made a full upper set of teeth for a lady of high rank, holding the same in place with springs, and relates that the lady ate with it easily and could not get along without it. He also relates having made a full upper and lower set for a gentleman, who had worn them for more than twenty-four years. When a full upper set of teeth was made, Fauchard used flat springs to hold the piece in place, atmospheric suction not being recognized and used until the year 1800. He states, however, that he has been successful in three cases in placing full upper sets without the aid of springs. He also brought palatine prosthesis to a high degree of perfection and described five kinds of obturators, which were, however, somewhat-complicated. The materials most in use in dental prosthesis were human teeth, hippopotamus tusks, ivory of the best quality and ox bone. Crowns were placed on natural roots (if healthy) and held in place with screws or bound to neighboring teeth. The second edition of Fauchard’s work, which appeared in 1746, contains (pp. 275-277) the first account of pyorrhea alveolaris, familiarly called “Riggs’s disease,” after the American dentist, Dr John M Riggs, who, in 1876, introduced the method of scraping the tartar from the crowns and roots for its cure. In the first edition of Fauchard’s work (vol. ii, p. 30) mention is made of a machine for preparing and drilling into teeth. This machine is illustrated in Siemens d’Odontologie (Jourdain, 1756, p. 207). This was no doubt the beginning of the dental engine, and antedates the dental engine that the Greenwoods made from an old spinning wheel. Summing up his writings, we may say that, notwithstanding the falsity of some of his ideas, he was far in advance of his profession and was truly the founder of modern dentistry, and has given inestimable service to suffering humanity. During the first part of the nineteenth century, almost all plates were fitted for the attachment of springs in case they were needed look natural. Mouton also invented a method of applying partial dentures by fixing them to the natural teeth

with springs or clasps. He also practiced transplantation of teeth as well as the correction of dental irregularities, and gained great renown thereby. He used subluxation of the teeth for the purpose of severing the dental nerve as a remedy against toothache. Philip Pfaff, dentist to Frederick the Great, deserves passing mention, since he was the first German to write a real treatise on dentistry. He is the first author who practised capping an exposed nerve before placing a filling in the cavity, Fauchard usually filling the cavity directly over the exposure. He also described the construction of artificial teeth in which he made use of not only ivory, bone and tusks of the hippopotamus and the sea cow, but also of silver, mother of pearl and even enameled copper. His most important contribution to science was the invention of the plaster model, poured in a beeswax impression. Bourdet, dentist to the King of France, wrote a book on dentistry in 1757, in which the novel idea was advanced of extracting carious teeth, filling them with gold or lead and then replanting them. If the alveolus was injured he replanted the teeth immediately and performed the operation of filling afterward. He also used prosthetic pieces made entirely of gold and covered them with fleshcolored enamel on the outside, showing that some dentists of olden times were even more artistic than a large proportion of the practitioners of the present day who make no pretence of hiding their glaring gold crowns. He also made use of prosthetic pieces of hippopotamus tusk, to which human teeth were fastened with rivets. Thomas Berdmore, who was dentist to George III of England and the first dentist to the English Royal Family, is mentioned as having instructed Robert Wooffendale, by many reputed to have been the first dentist in America. Wooffen dale emigrated to America in 1766, and though he was preceded by several men who practised the art, he was probably far more efficient than any who preceded him. In 1768 Berdmore published an excellent work on dentistry which went through many editions three English, two German and the last an American edition, appearing in Baltimore, the cradle of American dentistry, in 1844, 76 years after the first edition, affording splendid proof of its value.

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History of Dentistry

John Hunter (the celebrated English surgeon (born February 13, 1728), studied under his brother William, who conducted a school of anatomy in London. In 1771 he published a book entitled Natural History of the Human Teeth, and in 1776 another work entitled Practical Treatise on the Diseases of the Teeth. He was a great lecturer and writer and kept a superb anatomical collection and extensive library. So great did his fame become that he was made Surgeon-General to the English Army. Hunter was a strenuous partisan of replanting and transplanting teeth, and described these operations much more fully than had been done before. He experimented by transplanting a sound tooth drawn from a living person into a cock’s comb by making an incision with a lancet. When, some months later, the cock was killed the head was injected and examined and the tooth was found to be attached and circulation established as is found in the natural gums. If we may judge from early writings, transplanting and replanting were far more common at that time than at present, and also profitable, as may be judged by the charges of Paul Eurialius Jullion, whose fee was five pounds five shillings for transplanting a live tooth and two pounds two shillings for a dead tooth.

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Robert Bunon (died 1749), a French dentist born at the beginning of the eighteenth century, was one of the first to deny that the eye tooth has anything to do with the organ of sight, showing that it is supplied by the infraorbital nerve. He was an ardent champion of conservative dentistry and prophylaxis and succeeded in converting many medical men, surgeons and priests to his views. When Fauchard’s book, Le Chirugien Dentiste, appeared he was disappointed to find but little therein that interested him, and set about to write a book of his own. Before publishing his work he entered the College of Surgery to undertake two years’ practice with a regularly licensed surgeon, to undergo theoretical and practical examinations and to take oath before the Chief Surgeon of the Realm in accordance with the edict of May, 1699, in order to obtain the diploma of surgeon- dentist. He was highly eulogized by the principal journals of the time, and by this means won much fame and many wealthy clients. One of the chief merits of his book is that of having ascribed to the deciduous teeth all of the importance that they really have. In cases of stomatitis, Bunon advised the complete removal of tartar before administering other treatment. He used the same measures against mercurial stomatitis in the specific treatment of syphilis.

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Introduction to Orthodontics • Definition of Orthodontics • What is Malocclusion? • Aims of Orthodontic Treatment – Functional Efficiency – Structural Balance – Esthetic Harmony • Branches of Orthodontics – Preventive Orthodontics – Interceptive Orthodontics – Corrective Orthodontics • Orthodontic Appliances – Removable Orthodontic Appliances

– Fixed Orthodontic Appliances – Functional Appliances – Orthopedic Appliances/ Extraoral Force Appliances • Timing of Orthodontic Intervention – Deciduous Dentition – Early Mixed Dentition – Late Mixed Dentition/Early Permanent Dentition

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– Correcting Malocclusions of Dental Origin – Correcting Malocclusions of Skeletal Origin – Adult Orthodontics – Guards – Management of Dentofacial Anomalies • Benefits of Orthodontic Treatment

• Scope of Orthodontics – Monitoring and Assessment of Developing Dentition

Humans have attempted to straighten teeth for thousands of years before orthodontics became a dental specialty in the late nineteenth century. Proper alignment of teeth has long been recognized to be an essential factor for esthetics, function and overall preservation of dental health. Malposed/poorly aligned teeth may predispose to a number of unfavorable sequelae such as poor oral hygiene predisposing to periodontal diseases and dental caries, poor esthetics giving rise to psychosocial problems, increased risk of trauma, abnormalities of function and temporomandibular joint (TMJ) problems (Box 2.1). Orthodontics is the branch of dentistry concerned with the growth of the face, development of occlusion and the prevention and correction of occlusal anomalies/abnormalities. The term “orthodontics” comes from Greek: “orthos” meaning right or correct and “odontos” meaning tooth (Flow

chart 2.1). The term orthodontics was first coined by Le Felon in 1839. DEFINITION OF ORTHODONTICS Knowing the definition is often an important initial step in understanding any subject. A number of definitions have been put forward over

Box 2.1: Unfavorable sequelae of malocclusion • • • • • • • •

Poor facial appearance Poor oral hygiene maintenance Risk of dental caries Risk of periodontal diseases Abnormalities of functions Psychosocial problems Risk of trauma to the teeth TMJ problems.

Introduction to Orthodontics

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Flow chart 2.1: Derivation of the term orthodontics

the years to explain what orthodontics is. Some of the widely followed definitions are given below: In 1911, Noyes gave the first definition of orthodontics as, “The study of the relation of the teeth to the development of the face and the correction of arrested and perverted development.” In 1922, The British Society of Orthodontists proposed that, “Orthodontics includes the study of growth and development of jaws and face particularly and the body generally, as influencing the position of the teeth; the study of action and reaction of internal and external influences on the development, and the prevention and correction of arrested and perverted development.” Later, the American Board of Orthodontics (ABO) and the American Association of Orthodontists (AAO) stated that, “Orthodontics is that specific area of dental practice that has as its responsibility, the study and supervision of the growth and development of the dentition and its related anatomical structures from birth to dental maturity, including all preventive and corrective procedures of dental irregularities, requiring the repositioning of teeth by functional or mechanical means to establish normal occlusion and pleasing facial contours.” WHAT IS MALOCCLUSION? The term ‘malocclusion’ was first coined by Guilford and it refers to any irregularities in occlusion beyond the accepted range of normal. Malocclusions are caused by hereditary or environmental factors or more commonly, by both the factors acting together. One of the most common causes of malocclusion is a disproportion in size between the jaw and the teeth or between the maxillary and the mandibular jaws. A child who inherits mother’s small jaw

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and father’s large teeth may have teeth that are too big for the jaw, causing crowding in the arch. Abnormal oral habits, such as thumb/digit sucking, lip biting and mouth breathing may also cause malocclusion by adversely affecting the normal occlusal development. Malocclusion can be presented in a number of ways. Some of the common characteristics of malocclusion include: • Overcrowded teeth • Spacing between the teeth • Improper “bite” between maxillary and mandibular teeth • Disproportion in the size and the alignment between the maxillary and the mandibular jaws. It must be appreciated that not all malocclusions need treatment. Treatment of malocclusions that are mildly unesthetic and not detrimental to the health of the teeth and their supporting structures may not be needed and is not justified. AIMS OF ORTHODONTIC TREATMENT Although orthodontic treatment improves facial appearance and is occasionally performed for cosmetic reasons, it should be aimed at restoration of overall dental health. Jackson has summarized the aims of orthodontic treatment that are popularly known as Jackson’s triad (Fig. 2.1). They are: i. Functional efficiency ii. Structural balance iii. Esthetic harmony. Functional Efficiency The teeth along with their surrounding structures are required to perform certain significant functions such as mastication and phonation. Orthodontic treatment should increase the efficiency of the functions performed. Structural Balance Orthodontic treatment not only affects teeth but also the soft tissue envelop and the associated skeletal structures. The treatment should maintain a balance between these structures and the correction of one should not affect the health of the other.

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History of Orthodontics

change the normal course of events. They include the care of deciduous dentition with restoration of carious lesions that might change the arch length, monitoring of eruption and shedding timetable of teeth, early recognition and elimination of oral habits that might interfere with the normal development of the teeth and jaws; removal of retained deciduous teeth and supernumeraries which may impede eruption of permanent teeth and maintenance of space following premature loss of deciduous teeth to allow proper eruption of their successors.

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Interceptive Orthodontics

Fig. 2.1: Aims of orthodontic treatment (Jackson’s triad)

Esthetic Harmony The orthodontic treatment should enhance the overall esthetic appeal of the individual. This might just require the alignment of certain teeth or movement of the complete dental arch, including its basal bone. The aim is to get results which go well with the patient’s personality and make him or her look more esthetically appealing. BRANCHES OF ORTHODONTICS The general field of orthodontics can be divided into the following three categories based on the nature and time of intervention: • Preventive orthodontics • Interceptive orthodontics • Corrective orthodontics. Preventive Orthodontics Preventive orthodontics is defined as “Action taken to preserve the integrity of what appears to be the normal occlusion at a specific time.” As the name implies, preventive orthodontics includes actions undertaken prior to the onset of a malocclusion, so as to prevent the anticipated development of a malocclusion. Preventive orthodontics encompasses all those procedures that attempt to ward off untoward environmental attacks or anything that would

Interceptive orthodontics implies that when the action is taken, an abnormal situation (malocclusion) already exists. Certain interceptive procedures are undertaken during the early manifestation of malocclusion to lessen the severity of malocclusion and sometimes to eliminate the cause. Interceptive orthodontics is defined by the American Association of Orthodontists as “That phase of the science and art of orthodontics employed to recognize and eliminate potential irregularities and malpositions in the developing dentofacial complex.” Interceptive procedures include serial extraction, correction of developing anterior crossbite, control of abnormal oral habits, removal of supernumeraries and ankylosed teeth and elimination of bony or tissue barriers to erupting teeth. Certain procedures undertaken may be common to both preventive and interceptive orthodontics. However, the timing of the services rendered is different. Preventive orthodontic procedures are carried out before the manifestation of a malocclusion, while the goal of interceptive orthodontics is to intercept a malocclusion that has already been developed or is developing, so as to restore a normal occlusion. Corrective Orthodontics Corrective orthodontics, like interceptive orthodontics, is also undertaken after the manifestation of a malocclusion. It employs certain technical procedures to reduce or correct the malocclusion and to eliminate the possible sequelae of malocclusion.

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Introduction to Orthodontics

Corrective surgical procedures may require removable or fixed mechanotherapy, functional or orthopedic appliances, or in some cases an orthognathic/surgical approach.

therapy, e.g. retainers. Removable orthodontic appliances can be used in conjunction with fixed mechanotherapy. Fixed Orthodontic Appliances

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ORTHODONTIC APPLIANCES Today orthodontists have a wide array of appliances in their armamentarium to treat malocclusions. Success of orthodontic treatment depends on the appropriate selection of the appliances, the timing of the treatment, the type of tooth movement and/or skeletal changes desired, age of the patient and other factors. There are basically four types of orthodontic appliances, which can either be used singly or in combination to treat malocclusions. i. Removable orthodontic appliances ii. Fixed orthodontic appliances iii. Functional appliances iv. Orthopedic appliances/Extraoral force appliances. Removable Orthodontic Appliances Removable orthodontic appliances are so called because they can be removed and fitted back into the mouth by the patient (Fig. 2.2). Use of removable appliances requires careful case selection for the success of the treatment. They are ideally used when simple tipping movement of teeth is sufficient to correct a certain type of malocclusion. The range of malocclusions that can be treated with removable appliances alone is limited. They can also be used as passive appliances to maintain the teeth in their corrected positions after active phase of orthodontic

Fig. 2.2: Removable orthodontic appliance

Fixed orthodontic appliances are so called because they are fixed to the teeth and cannot be removed by the patient. Fixed orthodontic therapy involves fixation of attachments (brackets) to the teeth and application of forces by arch wires or auxiliaries via these attachments (Fig. 2.3). Fixed appliances are indicated when multiple tooth movements are required for correction of malocclusion, such as rotations and bodily movement of teeth. Fixed mechanotherapy allows fine finishing and settling of occlusion. There are a number of fixed orthodontic techniques such as: Begg’s, edgewise, preadjusted edgewise, straight wire and lingual techniques. Functional Appliances Functional appliances/myofunctional appliances are those appliances that utilize the forces of the circumoral musculature for their action to effect the desired changes (Fig. 2.4). They act principally by holding the mandible away from the normal resting position to effect growth modification of the mandible. Orthopedic Appliances/Extraoral Force Appliances Orthopedic appliances use extraoral forces of high magnitude (> 400 gm/side) to bring about skeletal changes. Intermittent application of such high forces in the growth period aids in correction of

Fig. 2.3: Fixed orthodontic appliance

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History of Orthodontics

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Fig. 2.4: Activator, a myofunctional orthodontic appliance

skeletal malocclusions by growth modification. Orthopedic appliances like functional appliances require good patient compliance for their success, e.g. headgears and chin cup (Fig. 2.5). TIMING OF ORTHODONTIC INTERVENTION Appropriate timing of orthodontic treatment is essential to accomplish the desired treatment outcome and its long-term stability. Timing of orthodontic intervention is related to the stage of dentition. Deciduous Dentition Orthodontic treatment during this stage mainly includes the following: • Parental education • Care of deciduous dentition • Space maintenance • Elimination of abnormal oral habits. Early Mixed Dentition Orthodontic treatment during this stage includes the monitoring of shedding timetable, serial extraction, space maintenance and control of abnormal oral habit. Although most corrective orthodontic procedures are performed in older children and adolescents, it may be advantageous in some cases to begin the treatment early before all the permanent teeth have erupted and facial growth is complete. Advantages of early orthodontic treatment include: • Correction of bite problems by guiding jaw growth and controlling the width of the upper and lower dental arches

Fig. 2.5: Orthopedic appliance

• Reduction or elimination of abnormal swallowing or speech problems • Growth modification using functional and orthopedic appliances is best done in this period where significant growth is taking place • Shortening and simplification of later orthodontic treatment • Prevention of later tooth extractions • Improvements in appearance and self-esteem • Parental education. Late Mixed Dentition/Early Permanent Dentition Most corrective orthodontic treatments are carried out in late mixed dentition or early permanent dentition stage. Late Treatment • Many types of orthodontic treatments are feasible after adolescence. However, growth modification procedures to correct skeletal malocclusion may not be feasible due to cessation of growth. • Surgical treatment involving orthognathic surgeries are best carried out in late teens/ early adulthood after the cessation of growth. SCOPE OF ORTHODONTICS From the era of finger pressure application to invisalign treatment, the field of orthodontics has

Introduction to Orthodontics

witnessed profound development in the form of newer appliance designs and techniques, which have only increased the scope of orthodontics.

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Monitoring and Assessment of Developing Dentition • Shedding and eruption schedule is closely monitored to ensure the normal course of events. • Space maintainers are given in case of premature loss of primary teeth to facilitate the eruption of successor teeth. • Habit breaking appliances are given to eliminate deleterious oral habits, such as thumb/digit sucking and lip biting which can adversely affect the development of dentofacial structures. • Planned extraction of certain deciduous and/ or permanent teeth (serial extraction), done in selected cases, can prevent future development of crowding by providing adequate space for the remaining teeth to erupt. Correcting Malocclusions of Dental Origin Malocclusions of dental origin include abnormalities of intra-arch alignment and interarch relationship of teeth. They can be managed by removable or fixed orthodontic appliances. Correcting Malocclusions of Skeletal Origin Skeletal malocclusions include conditions where the upper and lower jaws are abnormally related to each other. • Growth modification: Skeletal malocclusions can be treated successfully by modifying the growth of jaws during active growth period using functional or orthopedic appliances. • Surgical correction: Severe skeletal malocclusion in adults can be corrected by orthognathic/ surgical approach. Adult Orthodontics Better understanding of bone cell reactions to orthodontic forces and improvements in

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appliance design has made orthodontic treatment feasible in adult age as well. Orthodontic treatment in adults may involve the following: • Adjunctive orthodontic procedures: They refer to limited orthodontic treatment carried out to facilitate other dental procedures. Adjunctive orthodontic procedures include uprighting of tilted abutment teeth prior to bridge work, space gaining for placement of implants, etc. • Comprehensive orthodontic treatment: It is usually carried out in young adults and involves full fledged orthodontic treatment with or without extraction of teeth. Guards • Mouth guard/Sports guard: Mouth guards are often used during contact sports, such as boxing to prevent trauma to the teeth. • Night guards: Night guards can be given in bruxism to prevent further loss of tooth structures by attrition. Management of Dentofacial Anomalies Dentofacial anomalies such as cleft lip and palate are usually associated with impaired facial appearance, speech, hearing, mastication, deglutition, and dental occlusion. Thus, management of such patients often requires a multidisciplinary approach with a long-term treatment plan and individualized rehabilitation program designed to address the treatment needs. Malocclusion is usually present and orthodontic therapy with or without corrective jaw surgery is frequently indicated. BENEFITS OF ORTHODONTIC TREATMENT • Improved confidence. • Well aligned teeth that are easier to keep clean and healthy. • Ideally positioned teeth, which lessen the chance of gingivitis and advanced gum disease. • Closed spaces to avoid the need for a bridge or denture. • Better chewing and food digestion.

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History of Orthodontics from Ancient Civilization to Twentie th Century Twentieth

• Ancient Civilization

• Eighteenth Century

• Middle Ages Through Seventeenth Century

• Nineteenth Century • Twentieth Century

Since the beginning of human history, human beings have understood at a very basic level that without a proper bite, survival is very difficult. If you cannot chew well, you cannot eat well. Remains of the ancient Egyptians, Romans and the Etruscans show that these societies used various kinds of metal and ‘wires’ to straighten or adjust the teeth. Many advances in dentistry and some pioneering efforts in teeth straightening began in the 18th century, but it was really in the 19th century that orthodontics became a science of its own. Many inventors have contributed significantly to the fascinating science of orthodontics. The person, to whom, given the most credit for pioneering modern orthodontics is Dr Edward Angle, who is rightly honored as the “Father of Modern Orthodontics”. Angle developed a method for scientifically classifying, categorizing and identifying irregular bites. His classification of malocclusion, also known as the Angle classifications is still being used by dentists and

3

orthodontists to diagnose and treat patients; and even though methods for straightening teeth, like dental braces, have dramatically changed since the early 1900s, Dr Angle’s classifications have stood the test of time. The history of orthodontics is interesting and at the same time complex. It is the oldest speciality of dentistry. It would be wise to follow the development of this exciting field of science right from the era of ancient civilization to the current times. Prior to 1900s, the orthodontics was referred as “Regulation of Teeth” and as “Orthodontia” up to 1930s and “Orthodontics” up to 1970s and currently it is addressed as “Orthodontics and Dentofacial orthopedics” (Box 3.1). ANCIENT CIVILIZATION The history of orthodontics has been intimately interwoven with the history of dentistry for more than 2000 years. Dentistry in turn, has its origins as a part of medicine.

History of Orthodontics from Ancient Civilization to Twentieth Century

Box 3.1: Evolution of the term orthodontics

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• Orthodontics – “Regulation“ prior to 1900s – “Orthodontia” up to 1930s (“ia” referred to a medial condition) – “Orthodontics” up to 1970s – Currently “Orthodontics and Dentofacial orthopedics”

The Greek physician, Hippocrates (460–377 BC), was the first to separate medicine from fancy or religion. He established a medical tradition based on facts and the collected information was gathered into a text known as the ‘Corpus Hippocraticum’. This text of the pre-Christian era contains many references to the teeth and to the tissues of the jaws as part of the medical text, which includes descriptions of irregularity and crowding of teeth. Aristotle (384–322 BC), the Greek philosopher was the first writer who studied the teeth in a broad manner. In his work entitled De Partibus Animalium (On the Parts of Animals), he compared various dentitions of the known species of animals of that time. Aulius Cornelius Celsus (25 BC–50 AD), the prominent Roman author of the first century, described finger pressure to move teeth in his work De Re Medicina (on Medicine) (Table 3.1). When in a child, a permanent tooth appears before the fall of the milk tooth, it is necessary to dissect the gum all around the latter and extract it. The other tooth must then be pushed with the finger, day by day, towards the place that was occupied by the one extracted; and this is to be continued until it reaches its proper position. The medical art of the Romans reached its zenith under Claudius Galenus, commonly known as Galen (AD 130–200). For 15 centuries he dominated medical thought, and it was not

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until the Renaissance that the infallibility of his medical expertise was questioned. In his medical writings, he described dental anatomy and embryology by specifically identifying the origin, growth, and development of the teeth and enumerating the functions of each. He believed the teeth to be true bones. Because dissection was performed on animals rather than on human beings, he erroneously applied some of his findings to human beings (e.g. the presence of an intermaxillary bone and the insensibility of teeth). MIDDLE AGES THROUGH SEVENTEENTH CENTURY There is little reference to dentition during this period. An Arabic physician Paul of Aegina (Paulus Aegineta 625–690) wrote about irregularities in the dental arches caused by supernumerary teeth. He advised extraction of such teeth. Ambrose Paré (1517–1590), a French surgeon, paid specific attention to the cleft palate. He was the first surgeon to devise an obturator for treatment of cleft palate. Renaissance Period (Fourteenth to Sixteenth Century) During the Renaissance, one of the greatest geniuses of history, Leonardo da Vinci (1452– 1519), is remembered because he painted a smile on the lips of Mona Lisa. Her smile remains most provocative; yet the brush was only one of the many tools he mastered. He was the first artist to dissect the human body for the acquisition of anatomic knowledge and the first to draw accurate pictures of these dissections. Leonardo was the first to recognize tooth form and the first to realize that each tooth was related to another tooth and to the opposing jaw as well, thus perceiving the articulation of the teeth. He

Table 3.1: Ancient civilization Years

Authors

Contributions to orthodontics

460–377 BC

Hippocrates

Description of irregularity “Corpus Hippocraticum”.

384–322 BC

Aristotle

Comparison of various dentitions of different species of animals in his work “On the Parts of Animals”.

25 BC–50 AD

Aulius Cornelius Celsus

Described finger pressure to move teeth in his work ‘De Re Medicina (On Medicine)’.

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History of Orthodontics

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described the maxillary and frontal sinuses and established their relationship to facial height. He determined and made drawings of the number of teeth and their root formations. He noted that “those teeth that are the farthest away from the line of the temporomandibular articulation are at a mechanical disadvantage as compared with those that are nearer.” Those (teeth) that act most powerfully, the mascellari (molars) have broad flattened crowns suitable for grinding the food, but not for tearing or cutting it. Those that act less powerfully, the incisors, are suitable for cutting the food but not for grinding it. The maestre (canines) are intermediate between these two sets, their function being presumably that of tearing the food. Andreas Vesalius (1514–1564), a Belgian physician and anatomist, set a precedent for the study of human anatomy when he personally performed a dissection. It had been the custom for students to do the dissections while the lecturer described the procedure and specimen. He proved Galen wrong in many areas of anatomic knowledge. His classic work, On the Fabric of the Human Body, became the foundation that reconstructed our knowledge of human anatomy and thereby laid the basis for the practice of medicine and surgery. In this book, he described the minute anatomy of the teeth, particularly the dental follicle and subsequent pattern of tooth eruption: Gabriele Fallopio (1523–1562), commonly known as Fallopius, an Italian anatomist, wrote in his Observationes Anatomica (Anatomic Observations) a detailed description of the dental follicle. He wrote the terms hard and soft palate. A membranous follicle is formed inside the bone furnished with two apices, one posterior (that is to say, deeper down, more distant from the gums), to which is joined a small nerve, a small artery and a small vein; the other anterior (that is, more superficial) which terminates in a filament. Inside the follicle is formed a special white and tenacious substance, and from this the tooth itself, which at first is osseous only in the part nearest the surface, while the lower part is still soft, that is, formed of the above mentioned substance. Each tooth comes out traversing and widening a narrow aperture, bare and hard; and in process of time the formation of its deeper part is completed.

Bartholomaeus Eustachio (1520–1574), commonly known as Eustachius, also an Italian anatomist, described the minute structure of many organs, especially the tube that connects the middle ear with the nasopharynx and that bears his name. He wrote Libellus de Dentibus (Book on the Teeth) in 1563, which is the first important specialized monograph on the anatomy of the teeth. In this book, he collected the writings of various authors from Hippocrates to Vesalius, added the results of his own researches, and gave the first accurate account of the phenomenon of the sequential development of the first and second dentitions. He described the eruption and the function of the teeth, contending that there was no analogy between the deciduous and permanent dentitions. Eustachius devoted more attention to the teeth than most anatomists, giving full descriptions of the different forms, number and varieties. He indicated the manner of articulation of the teeth and gave a somewhat ambiguous explanation of the nature of the attachment of the teeth to the socket and the gingival tissues, comparing the latter to the attachment of the nails to the skin. His explanation of the internal structure of the teeth differentiated the two layers and compared the enamel with the bark of trees. Eustachius described the dental follicle and its blood supply. He refuted the doctrine that roots of the deciduous dentition served to form the permanent teeth. He maintained that the germs of the permanent teeth are too small to be seen in the fetus. He also mentioned that the teeth are nourished differently than other bones, as witnessed by their inability to repair when fractured. The first book in the German language to have reference to the teeth was entitled “Arzei Buchlein” (A Book of the Surgical Art) and was published in 1530 (author unknown). It contains the following comment. When teeth begin to drop out push the new one every day toward the place where the first one was, until it sits there and fits among the others, for if you neglect to attend to this, the old teeth (deciduous) will remain and the young ones (permanent) will be impeded from growing straight. EIGHTEENTH CENTURY 18th Century witnessed major events in the development of dental science and dentistry

History of Orthodontics from Ancient Civilization to Twentieth Century

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Table 3.2: Eighteenth century Years

Author

Contributions to orthodontics

1772–1789

Etienne Bourdet

• Extraction of 1st premolars to preserve the symmetry of the jaws • Extraction of the mandibular 2nd molars shortly after eruption in case of child with protruded chin

1723

Pierre Fauchard

• Father of modern dentistry • He published his two-volume book entitled “The surgeon dentist, a treatise on the teeth” • Developed first expansion appliance called “Bandlette”

1728–1793

John Hunter

• • • •

Natural history of teeth Growth and development of jaws Internal structure of teeth Functions of teeth

(Table 3.2) were separated. France was the leader in dentistry throughout the world in the 18th century. This was mainly due to one person; Pierre Fauchard. No one person exerted a stronger influence on the development of the profession than he did. In fact, he is referred to as the ‘Founder of Modern Dentistry’. He created order out of chaos, developed a profession out of a craft and gave to this new branch of medicine a scientific and sound basis for the future. He published his two-volume book entitled “The Surgeon Dentist, A Treatise on the Teeth”, which had an entire chapter, on ways to straighten teeth. With reference to orthodontics, as early as 1723, he developed

what is probably the first orthodontic appliance. It was called a Bandelette (Fig. 3.1). It was designed to expand the arch, particularly the anterior teeth and was the forerunner of the expansion arch of modern times. John Hunter (1728–1793), an English surgeon and a great teacher of anatomy, published his book ‘The Natural History of the Human Teeth” in 1771. He demonstrated the growth, development and articulation of the maxilla and mandible, and outlined the internal structure of the teeth and bone and their separate functions. He gave the basic nomenclature of dentistry incisors, bicuspids and molars. The art of modern dentistry based on scientific foundation was first developed in Europe. It then came to the United States through the Europeantrained Operators for the teeth who came to America seeking fresh opportunities. Many native practitioners of America then began to “Regulate” teeth. Malocclusion was called ‘irregularities’ and their correction ‘regulation’ during this period. NINETEENTH CENTURY

Fig. 3.1: Bandelette designed by Pierre Fauchard to expand dental arches

Foundations were laid in the 19th century to the oldest specialty of dentistry – Orthodontics. It was in the latter part of the 19th (1880s) century that the speciality began to emerge. By the mid–19th century, basic concepts of diagnosis and treatment had begun. It was a time when each practitioner attempted treatment by devising their own method based on purely mechanical principles. At that time, orthodontics

24

History of Orthodontics

was part of prosthetic dentistry and the literature on the subject described orthodontics in the area of partial or total replacement of missing teeth. As early as in 1841, William Lintott, introduced the use of screws in his work ‘On the teeth’. He described premature loss of deciduous teeth as a cause of malocclusion, recommended that treatment be begun at age of 14 or 25 years and also described a bite opening appliance.

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JS Gunnell, in 1840, introduced the chin strap as occipital anchorage for the treatment of mandibular protrusion, the principle of which is used even today. Emerson C Angel (1823–1903), in 1860 was the first to advocate the opening of the median suture to provide space in the maxillary arch, since he strongly apposed extraction. This began the use of arch expansion in orthodontics (Fig. 3.2). William and Magill, developed molar bands (Fig. 3.3) on the teeth as early as in 1871. It was not until the latter part of the 19th century, when a few dedicated dentists gave special attention and importance to this phase of dentistry, that orthodontics began to emerge as a speciality science. It was known at that time as ‘Orthodontia’, the suffix ‘ia’ referred to a medical condition. In the last three decades of 19th century, some great contributions were made to the speciality by the following dentists. John Nutting Farrar (1839 – 1913), is often referred as the “Father of American Orthodontics”. It was

he who gave impetus to the scientific investigations that permitted the understanding of the theory and practice of orthodontics. During his studies, he investigated the physiologic and pathologic changes occurring in animals as the result of orthodontically induced tooth movement. He published two volumes entitled “Irregularities of the Teeth and Their Correction” in 1888 and 1889. This textbook was the first great work devoted exclusively to orthodontics. Farrar was good at designing brace appliances and was the first to suggest the use of mild force at timed intervals to move teeth—‘in regulating the teeth, the traction must be intermittent and must not exceed certain fixed limits.’ He also was the first to recommend root or bodily movement of the teeth. Another man who also deserves much credit during this period of time is Norman N Kingsley (1829–1913), a prominent dentist, artist, sculptor and orthodontist. He is known for his works on ”Correction of cleft palate”. As early as in 1866, he devised a technique called ‘Jumping the bite’ with the use of a bite plane. He used vulcanite on conjunction with ligatures, elastic bands made of rubber, jackscrews and the chin cap. Henry A Baker, is remembered for the introduction of the so-called Baker anchorage or the use of the intermaxillary elastics (Fig. 3.4) with rubber bands in 1893 (Table 3.3). TWENTIETH CENTURY The most dominant, dynamic and influential figure in the specialty of orthodontics was

Fig. 3.2: Expansion appliance developed by Emerson C Angel

Fig. 3.3: Molar band

History of Orthodontics from Ancient Civilization to Twentieth Century

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Table 3.3: Nineteenth century Year

Author

Contributions to orthodontics

1841 1840 1860

William Lintott JS Gunnell Emerson C Angel

1871 1888 and 1889

William and Magill John Nutting Farrar

1829 to 1913

Norman N Kingsley

1893

Henry A Baker

Introduced the use of screws Introduced chin strap • First to introduce arch expansion by opening midpalatal suture • “Father of expansion appliances”. Developed molar bands • “Father of American orthodontics” • Wrote “Irregularities of the Teeth and Their Correction”. This textbook was the first great work devoted exclusively to orthodontics • Laid the foundation for “Scientific orthodontics” (intermittent forces, limits to amount of tooth movements) • “Treatise on Oral Deformities“ worked on correction of cleft palate • Extraoral traction Baker’s anchorage (Intermaxillary elastics)

Fig. 3.4: Baker’s anchorage (Intermaxillay elastics)

Edward H Angle (1855–1930) (Fig. 3.5). He is regarded as the “Father of Modern Orthodontics”. His classification of malocclusion was published in the Dental Cosmos, in 1899. Angle developed a classification of malocclusion based on this principle, which is still used today. Edward Hartley Angle (1855–1930) Angle was born on June 1, 1855, in Herrick, Pennsylvania. He graduated from Pennsylvania College of Dentistry, in 1878. It was then that he started his first orthodontic case on his preceptor’s son. The problems that arose stimulated him to devote the rest of his life to orthodontics. He presented his first scientific paper in 1887 before the ninth International Medical Congress. In the same year, his first paper bound edition

Fig. 3.5: Edward Hartley Angle (1855–1930)

book on orthodontics was published, and the last fully revised seventh edition appeared in 1907. He became professor of orthodontics in the year 1892. Angle started the first school of Orthodontics in St Louis in 1900, independent from any university. From 1900 to 1928 he was the active head of his school, first in St Louis, later in New London, Connecticut and finally in Pasadena, California. Under Angle’s aegis, the American School of Orthodontists was founded in 1901. Angle introduced the most universally used classification of malocclusion, and even developed a number of appliances such as the E-arch, the

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26

History of Orthodontics

pin and tube appliance, the ribbon arch appliance and the edgewise appliance. He has been given the most credit for pioneering modern orthodontics is Dr Edward Angle. Dr Angle developed a method for scientifically classifying, categorizing and identifying irregular bites. His malocclusion classifications, also known as the Angle Classifications are still used by dentists and orthodontists today to diagnose and treat patients. And even though methods for straightening teeth, like dental braces, have dramatically changed since the early 1900’s, Dr. Angle’s classifications have stood the test of time. Although Angle died on August 11, 1930, his influence is still felt very strongly in the orthodontic field. The whole world still uses his classification of malocclusion and his excellent descriptions of occlusion are hardly less important than his classification of malocclusion. His strong opposition against extraction of teeth as a part of orthodontic therapy has served as a balance wheel against promiscuous tooth removal. His mechanical genius has provided some of the most efficient appliances in use at present. Another distinguished orthodontist was Calvin S Case [(1847–1923) (Fig. 3.6)]. He developed a classification of malocclusions that included 26 divisions. Case published his major work “A practical treatise on the techniques and principle of dental orthopedic and prosthetic correction of the cleft palate”. Case was a strong

Fig. 3.6: Calvin S Case (1847–1923)

advocate of the relationship of malocclusion to facial improvement. Facial improvement was a guide to treatment. 1847–1923 One of the great pioneers in orthodontics, Calvin Case, was born in Jackson, Michigan, on April 24, 1847. He graduated dentistry and medicine from Ohio Dental College in 1871 and University of Michigan Medical School in 1884, respectively. He became Professor of Prosthetics and Orthodontics, at Chicago College of Dental Surgery. He dropped his professorship of prosthetics in 1896 and later continued in only orthodontics throughout his life. As a prolific writer, Case wrote 123 articles in dental literature alone on orthodontic diagnosis, orthodontic appliance, problems of tooth movement, cleft palate and associated speech problems, and prosthetic restorations of normal speech and function. He was the second author next to Angle. His textbook, the Techniques and Principles of Dental Orthopedia, was published in 1908. Case was also a pioneer in orthodontic mechanotherapy. He was the first one to stress the importance of root movement (1892). He was one of the first to use rubber elastics in treatment (1892), small gauge, and light resilient wires for tooth alignment (1917). He pioneered the use of relieves to stabilize orthodontic results. He is regarded as the outstanding man of his time in the prosthetic aspect of rehabilitation of cleft palate deformities. Charles A Hawley (1861–1929), used a celluloid sheet containing a geometric figure that when adapted to a model determined the extent of proposed tooth movement (1905) and introduced the retainer appliance (Fig. 3.7) that bears his name (1908) (Table 3.4). In 1931, B Holly Broadbent published an article in the first issue of the new Angle Orthodontist entitled. “A New X-ray Technique and its Application to Orthodontia”. It was the introduction to the specialty and to dentistry of cephalometric roentgenography (Fig. 3.8) and, of course, cephalometric tracing and evaluation. Broadbent devised the roentgenographic cephalometer, which is the instrument that accurately positions the head relative to the film

History of Orthodontics from Ancient Civilization to Twentieth Century

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Table 3.4: Twentieth century Year

Author

Contributions to orthodontics

1855 to 1930

Edward H Angle

1847 to 1923

Calvin S Case

1861 to 1929

Charles A Hawley

• Father of orthodontics • Classification of malocclusions • E-arch appliance • Pin and tube technique • Edgewise technique • Advocated extractions to correct facial deformities • First to use elastic • First to use light wires • Great contribution to prosthetic correction in cleft palate patients Hawley retainers

Fig. 3.7: Hawley’s retainer introduced by Charles A Hawley

Fig. 3.8: Cephalometric roentgenography (Lateral cephalogram)

and the X-ray source. His study, supported by the Bolton family, consisted of a longitudinal study of 3,500 school children from birth to adulthood. In honor of his sponsor, Broadbent established a new point of reference on the skull, known as the Bolton point. H D Kesling introduced his philosophy of tooth movement by using a rubber tooth positioning device, in which the teeth were moved into a more ideal cuspal relationship after major correction has been accomplished (1945).

Changes in the area of practice include a resurgence of treatment of the adult patient and its concomitant expertise, as the public becomes aware of personal dental health and esthetics. Included also are the invasion of areas that had not received much attention in the past, namely, orthognathic surgery and the problems associated with the temporomandibular joint. Orthodontics has achieved the status of a recognized specialty of dentistry because of a long period of craftsmanship and professional expertise.

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History of Orthodontics in United States of America • American Orthodontics (1800– 1840) – Benjamin James – Samuel S Fitch – M Bourand • • American Orthodontics (1840– 1875) – Chapin A Harris

– – – –

Thomas W Evans Emerson C Angell O A Marvin William E Magill

American Orthodontics (1875– 1900) – John H Farrar – Norman W Kingsley

In Colonial America, primitive conditions for dental care existed for almost a century until European-trained operators for the teeth came to this country seeking fresh opportunities. The art of dentistry in America can be said to have had its origin with the importation of these practitioners to the colonies. One of the most important native practitioners was John Greenwood (1760–1819). His skills were first learned from his father, who was an instrument maker. He was apprenticed to Dr Gamage, who taught him the rudiments of the dental art. Through experience, he became proficient in the practice. Other practitioners include Josiah Flagg (1763–1816) of Boston, who advertised that he “regulates teeth from their first teeth, to prevent pain and fevers in children, assists nature in the extension of the jaw, for a beautiful arrangement of a second set of teeth.” In 1798 CW Whitlock of Philadelphia stated that he supplies the deficiencies of nature files, regulates, and extracts teeth. John Le Tellier, also of Philadelphia states, “regulates teeth from their

– – – – – –

4

Alton H Thompson Isaac B Davenport Henry A Baker Eugene S Talbot Simeon H Guilford WGA Bonwill

first cutting in children” (1804). B Fendall of Baltimore advertised that he “regulates the teeth of children” (1784). Leonard Koecker (1728–1850), practiced in Philadelphia, advertised that he supplies ligatures to teeth of an irregular position. He stated this in his published articles in the medical press (1826): “Irregularities of the teeth is one of the chief predisposing causes of disease, and never fails even in the most healthy conditions to destroy, sooner or later, the strongest and best set of teeth unless properly attended to. It is not only a most powerful cause of destruction of the health and beauty of the teeth but also to the regularity of the features of the face, always producing, though slowly, some irregularity, but frequently the most surprising and disgusting appearance. It is, however, a great pleasure to know that dental surgery is abundantly provided with a remedy, and in most delicate subjects if placed under proper care at an early age, the greater portion of the teeth of the permanent set may invariably be preserved to perfect health and

History of Orthodontics in United States of America

regularity”. A note about his recomm-endation for extraction is as follows. He advocated the extraction of first molars “since they are generally predisposed to disease and if these teeth be extracted at any period before the age of twelve years, all the anterior teeth will grow more or less backwards, and the second and third molars so move toward the anterior part of the mouth to fill up the vacant space”.

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American Orthodontics (1800–1840) Irregularity of the teeth had been recognized by dental surgeons early in the nineteenth century. Benjamin James (1814) noted that he was “often called upon to cure irregularity, than to prevent it.” Levi S Parmly (1819) stated, “where irregularities are allowed to proceed and become fixed, it is often a matter of difficulty, and sometimes of impossibile to rectify them.” Samuel S Fitch, MD, whose book entitled A System of Dental Surgery, published in 1829, is considered the first definitive work on dentistry in this country, devoted a significant amount of information to irregularities of the teeth. He was the first to classify malocclusion, what is as follows: ‘There are four states of this kind of irregularity. The first when one central incisor is turned in, and the under teeth come before it, whilst the other central incisor keeps its proper place, standing before the under teeth. The second is, when both the central incisors are turned in, and go behind the under teeth; but the lateral incisors are placed properly and stand out before the under teeth. The third variety is when the central incisors are placed properly but the lateral incisors stand very much in; and when the mouth is shut, the under teeth project before them and keep them backward. The fourth is, when all incisors of the upper are turned in, and those of the under jaw shut before them’. His treatment consisted of applying “a force which shall act constantly upon the irregular teeth and bring them forward; the other force to remove that obstruction which the under teeth, by coming before the upper, always occasion.” This is done by “application of an instrument adapted to the arch of the mouth, fastening a ligature on the irregular tooth and removing the resistance of the under teeth by placing some intervening substances between the teeth of the upper and under jaw, so as to prevent them from completely closing.”

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Other practitioners found various forms of treatment, such as the use of gold or silver plates “to exert a gentle but continued pressure.” Shearjashub Spooner (1809–1859) wrote in his Guide to Sound Teeth (1838), “we have to consider, first, their general appearance as to regularity to the central circle; and, second, the state of preservation of each individual tooth in cases where there is a predisposition to a projecting chin”. M Bourand from Paris observed that the parents should be alerted to the shedding of the deciduous teeth and any possible deformity. He stated: “Defects, sometimes, which are of such magnitude, that I have known, in my long practice in both hemispheres, some young ladies of respectable families and of elegant features who could not observe their smiling countenances in a looking glass without blushing at the irregularities of their teeth; when comparing their mouths with some of their young friends toward whom their parents had bestowed all the necessary care to regulate their growth from childhood”. American Orthodontics (1840–1875) The correction of irregularities, however, easy in theory, will be found most difficult and delicate in practice; not only will much skill be found requisite, but, in equal degree, patience. Thus, by the mid-nineteenth century basic concepts of diagnosis and treatment had begun. It was a time when each practitioner attempted treatment by devising his own method based on purely mechanical principles. Orthodontics was part of prosthetic dentistry, and the literature on the subject described orthodontics in the area of partial and total replacement. Chapin A Harris (1806–1860), one of the most influential dental surgeons during this period, published the first modern classic book on dentistry, “The Dental Art”, in 1840. In it he gives much attention to various orthodontic treatment procedures that were adapted from French and English practitioners. His personal technique included the use of gold caps on molars to open the bite and knobs soldered to a band for tooth rotations. Materials generally used were cotton or silk ligatures, metallic wedged arches, and wooden wedges, but the discovery of vulcanite, a material used for artificial dentures, permitted the

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30

History of Orthodontics

construction of bite plates and other forms of removable appliances. In addition, springs that were to be attached to the metal frames for use in individual tooth movement were introduced. As early as 1841, William Lintott introduced the use of screws. They were described in the chapter entitled “Irregularities of the Teeth”, as: “When any one or more teeth project beyond the right line, and it is desired to move them inwards, a small hole must be drilled through the bar, over against the most prominent point of each; a screw-thread is then to be cut and a short screw introduced, which working through the bar, will, by a turn or two, each day, keep up such a continued pressure against each tooth as will quickly force it back as desired. He described the premature loss of deciduous teeth as a cause of malocclusion, explained that crowding was due to faulty growth and development. He recommended that treatment should begin at the age of 14 or 15 years and also described a bite-opening appliance, which consisted of a labial arch of a light bar of gold or silver passed around the front surfaces of the teeth by means of ligatures (known as Indian twist), and the necks of the irregular teeth with pressure applied for movement. In this manner, any required movement of the teeth, inwards or outwards may be affected with great ease, and in very little time causing no serious annoyance to the patient, the whole apparatus being removed and cleansed every two or three days. A modification of the screw, called the crib, was introduced by the Frenchman JMA Strange in 1841. Strange also introduced the use of the clamp band. For retention he advised: Of use a rubber band attached to some hooks on the appliance surrounding the molars for retention.” The chin strap as occipital anchorage for the treatment of mandibular protrusion was introduced by JS Gunnell in 1840, and the principle of this may be seen today. Occipital anchorage was obtained by the use of headgear devised by F Christopher Kneisel. In 1852 the American Society of Dental Surgeons, the first National Dental Association, established in this country (1840), committed to a great interest in this phase of dentistry, formed a committee on dental irregularities. The first

report was given by E J Tucker, a respected dental surgeon of Boston, in 1853. He condemned the practice of early extraction of deciduous teeth and advocated the use of rubber bands, or tubes, for tooth movement. He said, “The exact position of the teeth, the lines of force to be observed, and the tenacity of the power exerted, are all considerations requiring study and a careful judgment.” This same society sponsored the publication of the first book on orthodontics, Essay on Regulating the Teeth (1841). It was written by Solymon Brown (1790–1876) of New York, and was intended to inform parents by stressing the importance of preventing irregularities. In 1854 Thomas W Evans (1823–1897), an American dentist practicing in Paris, France, published the requirements for an appliance in the Dental Newsletter, which are as follows: First: a firm support which shall not loosen or in any way injure the teeth to which it is attached; Second: a steady and sufficient pressure; Third: great delicacy of construction that the apparatus may be a light as possible; Fourth: as a mechanism as simple as the case will admit. In 1860 Emerson C Angell (1823–1903) was probably the first person to advocate the opening of the median suture to provide space in the maxillary arch, since he took a strong stand against extraction. James D White also perfected a removable vulcanite appliance with a hinge in a split palate (1860). OA Marvin (1828–1907), in 1866, outlined the objectives of orthodontic treatment–first: the preservation of correct facial expression; second: the restoration of such expression; Third: the proper articulation of the teeth for better mastication; Fourth: their orderly arrangement, with a view to preventing decay. As early as 1871 William E Magill (1825– 1896) had cemented bands on the teeth. It may be of interest to know that in 1864 George J Underwood of New York presented his graduation thesis at the Pennsylvania College of Dental Surgery (Philadelphia) entitled ”Orthodontia”.

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History of Orthodontics in United States of America

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American Orthodontics (1875–1900)

NORMAN WILLIAMS KINGSLEY (1829–1913)

It was not until the latter part of the nineteenth century when a few dedicated dentists gave special attention and importance to this phase of dentistry, that our specialty began to emerge. Known in that time as orthodontia, it required special mechanical skills and knowledge in such basic sciences as anatomy, physiology, and pathology. The period of the last three decades of the nineteenth century is studied in the framework of individual dentists and their contributions. Each practitioner developed his own theory and practice, some to a greater degree of excellence than others. Those to be discussed briefly include John H Farrar (1839–1913); Norman W Kingsley (1829–1913); Alton H Thompson (1849–1914); Issac B Davenport (1854–1922); Henry A Baker (1848–1934); Eugene S Talbot (1847–1925); Simeon H Guilford (1841–1919); and WGA Bonwill (1833–1899).

Norman Williams Kingsley (Fig. 4.1) was born on 2nd October 1829. Kingsley was one of the founders, who served as the first Dean of the New York University College of Dentistry. He received honorary degree from Baltimore College of Dental Surgery in 1871. Kingsley was a prolific writer, with over 100 articles on cleft palate rehabilitation, the inadequacies of cleft palate surgeries, obturators, orthodontic diagnosis, and orthodontic appliances. He was a prominent dentist, artist, and orthodontist. As early as 1866, he experimented with appliances for the correction of cleft palate and is associated with a technique known as jumping the bite with the use of a bite plate. It was the treatment for protrusion of the maxilla, not necessarily with extractions, shaping the dental arches to be in harmony with each other. He used vulcanite in conjunction with ligatures, elastic bands made of rubber, jackscrews, and the chincap. In 1880 he published A Treatise on Oral Deformities, which remained a textbook for many years. He, too, emphasized the importance of the relationship between mechanics and biology as the principle on which orthodontics should be based. His book was the first to recommend etiology, diagnosis, and treatment planning.

John H Farrar could be referred to as the Father of American Orthodontics. It was he who gave impetus to the scientific investigations that permitted the understanding of the theory and practice of orthodontics. He began his studies in 1875, during which time he investigated the physiologic and pathologic changes occurring in animals as the result of orthodontically induced tooth movement. As a result of his studies, he published a series of articles, between 1881 and 1887, in the Dental Cosmos, one of the leading dental journals, enunciating the principle that “in regulating teeth, the traction must be intermittent and must not exceed certain fixed limits.” He also published “Irregularities of the Teeth and Their Correction” (Vol. 1 in 1888 and Vol. 2 in 1889), in which he demonstrated the many uses of the screw as the motivating attachment and the basis of what he referred to as a system of orthodontia. (Copies of these books are in the American Association of Orthodontists library in St Louis, Mo). He stressed the “importance of the observance of the physiologic law which governs tissues, during movement of the teeth, the subject being to prevent pain.” Farrar was the originator of the theory of intermittent force, and the first person to recommend root or bodily movement of the teeth.

Fig. 4.1: Norman W Kingsley (1829–1913)

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History of Orthodontics

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Dr Kingsley died in 1913 in Patterson, New Jersey. Many of his contemporaries felt that the father of modern orthodontics had passed away. Calvin S Case wrote: “The longer orthodontics is practiced, the more respect the author has for the general teaching.” Enunciated 40 years ago and published in his inestimable text, by that most ingenious man of his days, Dr Norman Williams Kingsley, were the acceptable bases of practice, “Much success in treating irregularities will depend upon a correct diagnosis and prognosis.” Alton H Thompson was one of those forgotten dentists who made a valuable contribution to the specialty. He was recognized as an authority on comparative dental anatomy, which is certainly a basic consideration for orthodontists (He was a founder of the American Anthropological Society). He devoted himself to research into the dynamics of occlusion. This led him to the following analysis: a. The construction of the temporomaxillary articulation allows for lateral, anteroposterior, vertical, and oblique movements. b. The extent of maxillary development is reflected for the necessary support of the extensive masticating mechanism. c. There is a suppression of density and diameter of the maxillary bones. d. There is a predominance of the rotatory over the elevating muscles of mastication; and e. The special construction of the masticatory armature, i.e. the teeth, their vertices, parallel arrangement of the dental tissues, and the apposition of the crushing teeth. Isaac B Davenport, as early as 1881, had created an interest in the study of occlusion. He developed a theory that the masticatory apparatus was subjected to the laws of nature, that imperfect occlusion was deleterious to the dentition, that extraction of teeth in treatment could affect the efficiency of the masticatory apparatus. He lectured before the New York Academy of Medicine in 1887. His lecture entitled “The Significance of the Natural form and Arrangement of the Dental Arches, With a consideration of the changes which occur as a result of their artificial derangement by Filing or by the Extraction of Teeth” has a tremendous

influence on the orthodontists. To provide a normal occlusion the practice of extraction of teeth was almost abandoned, being replaced by the expansion of the arch and the realignment of the teeth. While admitting the value of extraction as a means of correction of certain irregularities of the teeth, I am forced to believe that far more irregularities have been caused by extractions than could ever have been corrected by extraction. Henry A Baker is remembered, because in 1893 he introduced the so-called Baker anchorage, or the use of intermaxillary elastics (Fig. 4.2) with rubber bands. The introduction of intermaxillary elastics was interpreted by some practitioners to mean the elimination of the need for extraction. Clark Goddard was an early advocate of the study and research into comparative odontology, the study of skulls and teeth. This led to the acceptance of an expansion screw for the forcible separation of the maxilla. He also attempted to classify malocclusion, which included 15 separate types of irregularities. Eugene S Talbot was equally proficient in periodontics and orthodontics. He stressed the study of the causes of malocclusion to be the key to treatment. He stated that, “without the etiology of irregularities no one can successfully correct deformities, as is evident in the many failures by men who profess to make this a specialty.” He added, “Eighteen years of experience in the correction of irregularities of the teeth and a practical knowledge of the laws of mechanics

Fig. 4.2: Baker’s anchorage (Intermaxillary elastic—class III elastic)

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History of Orthodontics in United States of America

have taught me not to rely on any particular appliance. Frequently, though a certain appliance has worked well in one case it may not have been efficient in another case of similar nature. He advised that close attention to disproportion in the size of the maxilla and mandible, general contour and profile of the face, and the family history including hereditary factors important. He was one of the first to recommend the surgical exposure of impacted canines. In a paper presented to the Mississippi Valley Association of Dental Surgeons in March 1891, entitled “Scientific Investigation of the Cranium and Jaws,” he demonstrated intraoral measurements on cast with such instruments as the registering calipers and the T-square with graduated sliding indicator. This was one of the earliest attempts applying specific analysis of casts that reflected measurement of the jaws. Simeon H Guilford, dean of the Philadelphia Dental College, was regarded as one of the finest practitioners of that period. At the request of the National Association of Dental Faculties, he wrote the first textbook for students, Orthodontia: Malposition of Human Teeth, Its Prevention and Remedy, published in 1889. In this, he attempted to offer a classification of malocclusion. “There are two divisions—simple irregularities or the malposition of few teeth with no important facial disharmony, and complex irregularities, that is, malposition of many teeth having corresponding facial deformity” (These divisions contain eleven classes of malposition). He commented on extraction in treatments: “Probably no operation in the practice of orthodontia is more important, or has associated

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with it greater possibilities for good or evil to the patient than that of extraction”. WGA Bonwill said, “in vying with nature in matching the teeth, there must be more than mere mechanics, more than being capable of filling a tooth or treating an abscess–we must be dental artists.” He developed what is known as the Bonwill equilateral triangle. It is based on the mandibular analysis of a tripod arrangement, extending from the center of the condyloid process to the median line at the point where the mandibular central incisors touch at the cutting edge. His measurements of more than 2,000 cases showed that from the center of one condyloid process to the center of the other was four inches and that from the center to the incisor was also four inches. He used this theory in his orthodontic treatment. He advocated a specialty of orthodontics many years before Angle: “Really, in every city, someone should make of this a special practice, and the profession should encourage such by sending cases for inspection and consultation. And such a specialist should do all he can, in return to teach by example and demonstrations by clinics, to enlighten those who are placed so far from large cities that they are compelled to take such cases. When we can have that understanding between us, then we may feel as banded brothers more fully equipped for those hitherto difficult and thankless operations.” The principles of resorption and deposition of alveolar bone during tooth movement were discussed by LE Custer (Ohio) in March, 1888, at a meeting of the Mississippi Valley Dental Association, in a paper entitled “Intermittent Pressure: Its Relation to Orthodontia.”

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History of Orthodontics in Great Britain • Orthodontics in Britain – Bell – Medical Act of 1858 – Tomes

– – – –

Sir John Russell Reynolds Charles Goodyear 1878 Dentists Act JA Donaldson

Several eighteenth-century British authors, notably John Hunter, discussed the problems associated with irregular dentition. However, the first English textbook to be devoted to the subject matter of what would later be termed orthodontics appeared in 1803. Joseph Fox’s Natural History of the Human Teeth, subtitled, describing the proper mode of treatment to prevent irregularities of the teeth, detailed several practical methods for altering the position and orientation of teeth in the mouth. In 1829, Thomas Bell published The Anatomy, Physiology and Diseases of the teeth, in which he also discussed orthodontic problems and techniques. Five years later, William Imrie, in his interestingly titled Parents’ Dental Guide, attributed irregularity of teeth to “intemperance of various kinds, combined with artificial modes of living”. James Robinson published, The Surgical, Mechanical, and Medical Treatment of teeth in 1846, which contained his ideas on etiology and treatment. It is clear, from these texts, that procedures aimed at straightening the teeth were already part of the general dental surgeon’s repertoire by the first half of the nineteenth century. In 1829, Bell, lecturer at Guy’s Hospital on the anatomy and diseases of the teeth, expressed

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• The British Society for the Study of Orthodontics – Badcock

misgivings regarding the quality of much of the treatment on offer to “regulation cases”, as they were then termed. There is not a subject connected with that branch of practice, of which the present work professes to treat, which has given rise to such gross charlatanism, or to so much gratuitous cruelty, as that which regards the treatment or prevention of irregularity in the permanent teeth. Concerns of this sort were, however, not uncommonly voiced with regard to many aspects of dentistry at this time. The practice of dentistry was still unregulated; there were no recognized training programs or prerequisite educational requirements. The better-qualified practitioners, such as Bell, MRCS (later FRCS) and FRS, found much to complain about. In Britain, for much of the nineteenth century, dental work was undertaken by three dissimilar groups of practitioners. The members of the first group, small in number but perhaps the most influential, had recognized medical qualifications, which they had augmented by a short period of training in dentistry. These men were based predominantly in London and some of the larger provincial cities; most of them, like Bell, held hospital or dispensary appointments at some stage in their careers. The authors whose

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publications have been discussed above are representative of this group. The second group had acquired their dental skills primarily by way of an apprenticeship, of variable length and effectiveness, to an established dental practitioner. The number of this category of practitioners grew as the century progressed. The third group, perhaps the largest, and the most readily available to the general population, had little formal training and often combined their dental work with some other occupation, such as druggist or barber. The forms of treatment offered by the different groups varied. Those who were medically qualified tending towards a surgical orientation, which encompassed the whole of the buccal cavity. The second group, those who had followed the apprenticeship route, generally adopted a more mechanical approach, with an emphasis on the filling of teeth and the fitting of prosthesis. They would also perform extractions. The activities of this group most closely resembled the general dental practitioners of today. The services offered by the third group were more basic, chiefly involving the extraction of painful teeth. The Medical Act of 1858 regulated the practice of medicine, laying down statutory educational requirements and establishing a Medical Register, which was administered by the General Medical Council (GMC). The Medical Act also empowered the Royal College of Surgeons of England to award, by examination, a License in Dental Surgery. The first diet of this examination took place in 1860. Realizing the benefits of the Medical Act, the leading dentists, many of whom were, as noted above, medically qualified, and urged that similar provisions be made for dentistry. Sir John Tomes, MRCS (later FRCS) and FRS, was prominent in these campaigns. While Tomes and his peers were campaigning for the establishment of a regulated system of dental qualification and registration, they were also active in expanding dentistry’s institutional base. The Dental Hospital of London was founded in 1858, and it’s associated London School of Dental Surgery (LDS) in the following year. The rival Metropolitan School of Dental Surgery (which later became the National Dental Hospital) was also established in 1858, just before

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the Royal College of Surgeons of England began examining for the newly created LDS. The Edinburgh Dental Dispensary, run and staffed by surgeons, was founded in 1860. In 1863, the Odontological Society of Great Britain was formed, from the merger of two older, rival dental societies, under the leadership of Tomes and Samuel Cartwright, the professor of dental surgery at King’s College Hospital. A long political campaign achieved success in 1878, with the passage of the first Dentists Act, which extended the remit of the GMC to allow some regulation of dental practice. The Act also empowered the surgical colleges of Edinburgh and Dublin, and the Faculty of Physicians and Surgeons of Glasgow to offer examinations in dentistry similar to that of the London College. While it would be more than a further 40 years before all unregulated practice was finally controlled, the passing of the 1878 Act was an indication of the growing professional and social status of dentistry. Generalism had been the dominant ideology of nineteenth-century British medicine. In 1881, Sir John Russell Reynolds, later president of the Royal College of Physicians and the British Medical Association, maintained that “specialism” denoted “miserable retrogression instead of evolution (and) the survival not of the fittest, but of the charlatan and the quack”. As we shall see, similar views continued to be articulated by many, well into the twentieth century. However, as David Innes Williams has pointed out, the formation of the Royal Society of Medicine (RSM) in 1907 signaled a new, more positive, attitude to specialization within medicine itself. The RSM was organized into thirteen sections, rather than the traditional tripartite division of physic, surgery and obstetrics. The Odontological Society was incorporated into the RSM as one of its original constituent sections, which represented an acceptance of the place of dentistry within the medical establishment. By this time, specialization had little impact within general dentistry. However, many of the leading dentists, mostly members of the first group described above, regarded dentistry as a division within medicine and themselves as medical practitioners who had taken a special interest in dentistry. The meaning of specialism

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History of Orthodontics

varied, in other words, according to whether one regarded medicine or dentistry as the parent, generalist discipline. Meanwhile, the demand for treatment to correct irregularities of the teeth and jaws continued to grow. Earlier in the nineteenth century patients undergoing treatment to straighten their teeth were described as “regulation cases”; references to the fact that the aim of treatment was to correct what were called “irregularities of the teeth”. By the middle of the century, however, the term “malocclusion” was coming into common use. This change of vocabulary signaled a shift of emphasis away from a narrow focus just on the position of the front teeth, towards the consideration of both the relationship of teeth to each other, and to the teeth in the opposing jaw. The clinical practice of correcting malocclusion then became known as “orthodontia”. Later the term “orthodontics” was preferred. As the nineteenth century proceeded, the materials available to practitioners of “orthodontia” were improved and new methods were widely adopted. William Imrie, for example, made significant changes to orthodontic technique in the 1830s. He used plaster models of the dentition, made caps for teeth, which were soldered to arches to reinforce anchorage, and introduced gold bite plates to be used over the palate. A treatise by Charles Gaine, of Bath, published in 1856, is interesting in that it draws on the record of successfully treated cases. Gaine is credited with the introduction, simultaneously with WH Dwinelle in the USA, of the jackscrew into orthodontics, an innovation that was to have a great impact on the ability to move individual teeth and to expand the distance between rows of teeth. Gaine also recognized the need to maintain the teeth in their corrected positions for a period of time after tooth movement had been completed. Like Bell, he urged that orthodontic treatment be undertaken only by those competent to do so. The development of a technology specific to the correction of irregular dentition gave its practitioners a stronger claim to a distinctive skill, as well as a greater sense of professional identity. Vulcanite was patented, in 1844, by Charles Goodyear and rapidly found application in dentistry, providing a distinct improvement in

the production of both dentures and regulation plates. In a series of papers published in the 1870s, FH Balkwill described a further refinement in the use of the material, whereby the vulcanite was applied directly to the working plaster model of the teeth. This avoided the need to construct a model of the appliance in wax. The new technique significantly improved accuracy, and drastically reduced workshop time. Balkwill’s papers demonstrate that British dentists were actively involved uninnovation in the field of orthodontics in the second half of the nineteenth century. Although his appliances may seem crude by modern-day standards, they demonstrated many ingenious features, and appear to have been effective. Many of the nuances of tooth movement were, evidently, well appreciated at this time. Moreover, the fact that Balkwill worked in Plymouth indicates that the provision of orthodontic treatment was not limited to the metropolis. Following the 1878 Dentists Act, the newly created dental schools incorporated some teaching of orthodontics into their curricula. The 1882 “Student Supplement” of the British Journal of Dental Science listed lectures on irregularities of teeth as part of the dental surgery also pathology courses were offered at both the National Dental Hospital and the Dental Hospital of London. Orthodontic subject matter appeared both in the major general textbooks and in more specific volumes. Of the latter, James Oakley Coles’ On deformities of the mouth, congenital and acquired, and their mechanical treatment, first published in 1868, and J F Colyer’s Notes on the treatment of irregularities in position of the teeth, are notable. Articles on orthodontics began to appear regularly in the dental periodical literature. The first formal course of lectures on “what was later known as orthodontics” was delivered by John Henry Badcock, dental surgeon to Guy’s Hospital, shortly after his appointment in 1900. JA Donaldson, in his history of The National Dental Hospital, accurately describes the situation existing in most dental schools around the turn of the century: There was an increasing interest in orthodontics, partly as a result of lectures and writings by practitioners who had studied in the United States of America, and partly because it

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History of Orthodontics in Great Britain

was a field soon to be included in the requirements of examining bodies. By 1902, this led to the adoption by the National Dental Hospital of “rules for regulation cases” and the fitting up of a room on the first floor for their treatment, but no teacher was appointed at this time. The treatment of each case was undertaken by a student under the supervision of the dental surgeon of the day. In other words, orthodontic theory and practice were still being taught as integrated aspects of general dentistry. Nevertheless, from 1903 onwards, the staff lists of the Manchester Dental Hospital contained the names of a number of orthodontic demonstrators or tutors. In 1909, mention is made for the first time of the existence of a separate Orthodontic Department. In the same year, George G Campion was appointed as lecturer in orthodontics to the Victoria University, Manchester. By 1905 a “Regulation Room” had been established in the Royal Dental Hospital, staffed by the “Regulation Room House Surgeon”. By the beginning of the next decade, a number of other hospitals had followed suit. However, no formal postgraduate courses in orthodontics existed and many British dentists interested in the subject went to the United States for advanced training. For example, in the first decade of the twentieth century, Harold Chapman, Hubert Visick, AC Lockett, David Fyfe and Ernest Sheldon Friel, all attended the school run by the pre-eminent American orthodontist, Edward Angle, originally in St Louis. By this time, there were several full-time orthodontists in North America, most notably Angle himself, who had entered dedicated practice in 1892, but, as yet, none at all in Britain. A pupil of Angle, Friel, in Dublin, set up the first such practice in the British Isles in 1909. Orthodontics appears to have caught the dental imagination in the early years of the twentieth century. It is revealing, for instance, that the American, the British, the German, and the European orthodontic societies were all founded within ten years of each other. Some authorities, notably the leading historian of orthodontics BW Weinberger, have attributed this widespread surge of interest to the impact of Angle’s writings. There is certainly no doubt that, when compared to the situation in Britain,

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the teaching and the practice of orthodontics in North America were more established, better organized and more sophisticated, or that Angle was a dominant (if controversial) figure in American orthodontics. It is telling, for instance, that Angle’s pupils from the British Isles, notably Chapman, Friel and Visick, came to occupy leading positions within British orthodontics. Prolific authors of research papers, all three were founder members of the BSSO, Chapman and Friel serving as president. Angle’s teaching was predicated upon the assumption that orthodontics should be a specialty wholly independent of general dentistry. Part of the rationale for a specialist service, as he articulated it, was that the aim of treatment had become more ambitious. Its goal was now the establishment of “normal occlusion”. The objective was to place all the teeth in their correct relation, not only to their immediate neighbors, but also to their antagonists in the opposite jaw, and in a harmonious relation to the whole face. There was intense debate among orthodontists, in America and elsewhere, as to whether or not this ideal could be achieved in all patients and, if so, how. But the fact that this debate took place demonstrates the rising technical and aesthetic aspiration of practitioners of orthodontics. Angle’s bold assertion that orthodontics should be divorced from dentistry met with little support in Britain. An editorial in the British Dental Journal of 1902 stated: “Where the specialization of specialities may lead can hardly be foreseen, and we even await the prophesed eminent rhinologist devoted to the left nostril. That dental speciality admits of much division of labor without detriment is unquestionable, but the swing of the pendulum may well be too far. It appears that the orthodontist has already arrived in America, and there is a Society.” In North America, however, the trend to separate orthodontics from general practice was gathering pace. THE BRITISH SOCIETY FOR THE STUDY OF ORTHODONTICS It was from within this context of growing professional status and confidence, coupled with considerably improved technical capability, that

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History of Orthodontics

the British Society for the Study of Orthodontics sprung up. Practitioners in Britain were aware of the increasing presence of orthodontic specialists in North America, but did not seek immediately to emulate them in their advocacy of a separate specialty. There was, in any case, as an editorial in the dental journal Items of Interest noted, a difference in the interpretation of the word “specialist”, between England and the USA. In England, a “specialist” was often a general practitioner having an interest and expertise in a particular aspect of dentistry, whereas, in the USA, the term was used to designate someone who exclusively practiced in that field. The English interpretation of specialization would certainly be formative, as we shall see, of the first British specialist society. The driving force behind the creation of the BSSO was, without doubt, George Northcroft, who was a successful London dental practitioner. On 15 October 1907, Northcroft wrote to a number of his fellow practitioners inviting them to attend a preliminary meeting to discuss the foundation of a society, the object of which would be the promotion of the study of orthodontia. This meeting was held on 21 October 1907, in his rooms at 115 Harley Street, London. Eleven practitioners attended, in addition to North croft. Nine of those practiced in the West End of London, the other two being based in Wimbledon and Eastbourne, respectively. At least seven had hospital appointments. The founders of the BSSO were evidently drawn from the upper strata, in terms of their institutional, educational and social status, of the British dental profession. They were the heirs of the group of practitioners who had campaigned to raise the professional standing of dentistry in the second half of the nineteenth century. It was agreed to proceed with the plan of setting up a society. An inaugural meeting was held, by general invitation, in the room of the Medical Society of London, on 5 December 1907, which thirty-five people attended. Badcock was elected president, with Northcroft, James Sim Wallace, and Montagu Hopson being vice presidents. All four senior office-bearers held or had recently held, posts in one or other of the London hospitals. As already noted, Badcock had been, until 1905, dental surgeon and lecturer in dental surgery at Guy’s Hospital. Northcroft held a

similar appointment at the London Hospital Dental School, in the founding of which he had been closely involved. Sim Wallace, the author of the influential text Essay on the irregularities of the teeth (1904), was on the staff of several London hospitals over the course of his career, while Hopson eventually became head of the Dental School at Guy’s Hospital. The social and professional background of the early leaders of the BSSO is very revealing as to the character of the society and its aims. As Weisz has pointed out, in Britain, unlike North America or the rest of Europe, specialist expertise came to be identified as the unique possession of senior hospital staff. It was to hospital consultants, and only hospital consultants, that general practitioners referred patients in need of an expert opinion. What was odd and distinctively British about this arrangement, was that the hospital consultants espoused an ideology of gentlemanly holism and regarded themselves as medical generalists, albeit often with some degree of specific focus in their clinical interests. Thus, even the major beneficiaries of the process of specialization within British medicine did not present themselves as specialists per se. Such was the authority and prestige of the hospital consultant, especially those in the London teaching hospitals that this model came to be the definitive one for specialization in Britain. As we shall see, this pattern of specialist interest within an ostensibly generalist framework can be readily identified within the agenda of the BSSO. In his address to the inaugural meeting, Badcock, as president-elected, pointed out “there was now sufficient demand for a society, “where members could consult and advise each other upon the problems of the already large but increasingly important branch of dental surgery, orthodontia”. He felt, “the proposed name for the society should indicate that it was not the intention to create a group of specialists, practising orthodontia, but to provide an opportunity when everybody who was interested in both theory and practice could meet for mutual benefit”. The rules of the new society were closely modeled upon those of the existing Odontological Section of the Royal Society of Medicine, which were intended to ensure that the organization was non-political and disengaged

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History of Orthodontics in Great Britain

from controversy. One feature of the rule book, very revealing of the society’s self-image, was that members were to be prohibited from holding any commercial patents relating to dentistry. There was also an injunction against secret remedies, which were regarded as the staple of the “quack” specialist. One speaker at the inaugural meeting thought that the prohibition against patents would have an inhibiting effect upon the future development of dental technology. Nevertheless, the gentlemanly ethos of the upper strata of London medicine, with its pronounced antipathy to trade, prevailed and the rule was confirmed. This was again in marked contrast to American practice, where several orthodontists had taken out patents on technical innovations. The first full meeting of the BSSO took place in January 1908. As president, Badcock presented the first official paper. He chose, as his topic, the objectives of the new society and his views are very indicative of the state of orthodontics in Britain at this time. This is a very broad and inclusive remit for a special interest in dental or medical society, and is quite different in character from the nearest North American equivalent. It is clear that, in offering membership to all with an interest in orthodontics, regardless of occupational status, the BSSO did not constitute itself, at least primarily, as an organization to advance the professional interests of orthodontists. Rather than, the society defined its mission as the more disinterested one of encouraging the advancement of knowledge in the field. Again there are resonances here with the constitution of the RSM. As Innes Williams has recently argued, while the RSM represented the acceptance of a degree of specialization within British medicine, in presenting itself as a purely learned society, it effectively recognized specialties as categories of knowledge rather than divisions of practice. While the BSSO sought to encourage the improvement of corrective technique as well as the scientific understanding of normal and irregular dentition, the similarity of its aims with those of the RSM is noteworthy. To some extent, as Innes Williams notes, this emphasis was chosen to avoid engagement in issues relating to competition in the medical marketplace. Nevertheless, it is also true, as the

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quotation from Badcock indicates, that the founding figures of the BSSO evidently believed that development of the scientific and academic content of the subject would assist orthodontics in achieving a much more prominent place within dentistry as a whole. Badcock acknowledged that anxieties had been expressed that the creation of a new society, devoted solely to one particular branch of dentistry, could be divisive within the dental profession. But he regarded this apprehension as being groundless. He was not, however, in principle against specialization in the North American sense. He foresaw that eventually, at least in the larger centers of population, only fulltime specialists might provide an orthodontic service. In his judgment, this development would be beneficial. Interestingly, Badcock compared the advantages to be gained from orthodontic specialization to those that would accrue from the administration of anesthetics by specialist anesthetists, as against administration by general practitioners with an interest in anesthesia, which, he stated, was the usual practice at the time. In other words, Badcock was prepared, at least partially, to repudiate the view, widespread still among medical practitioners in Britain, that full-time specialization was necessarily to be deplored. As mentioned earlier, in the first decades of the twentieth century, North American orthodontics was riven by acrimonious controversy, relating to both the cause and the treatment of malocclusion. The society’s founders were very anxious that these divisions should not be replicated within the BSSO. With characteristic moderation, Badcock emphasized the Council’s desire to include representatives from all schools of thought. Another of the early presidents, Harry Baldwin, described the society as a “model of seductive humility” and was evidently proud that the society enjoyed a harmonious relationship with the generalist British Dental Association. Some of the controversy which disturbed North American orthodontics centered on Angle’s rigid insistence that it was bad practice to extract healthy teeth to facilitate tooth realignment. This tenet became the governing principle of those full-time American orthodontists who practised the Angle method.

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History of Orthodontics

Badcock argued, however, that many potential orthodontic patients could not afford either the money or time for prolonged and sophisticated treatment, and for those patients extraction was a necessary part of successful management. This was, effectively, a recognition of the differences between the British and American circumstances of orthodontic practice. Several of Badcock’s audience would have held appointments in voluntary hospitals where they would provide economical treatment for charitable patients. Moreover, British orthodontists knew that if they wished to expand the range of patients that they treated, it was necessary to make available a simplified form of treatment. On the other hand, Badcock also deplored those orthodontists who viewed treatment purely in empirical, mechanical terms. In his view, the realignment of the teeth could be successful, in the long-term, only if it was based upon sound biological principles. He admitted that the profession was still woefully ignorant in the fields of etiology, pathology and prophylaxis. Again the stated purpose of the Society was to be a disinterested forum, a vehicle for the advancement, not merely of technique, but of science. Badcock concluded by outlining the Council’s plans for furthering the aims of the Society. Future meetings would consist of the reading and discussion of papers, casual communications and clinical evenings of a practical nature. A library and museum would be created; investigation committees, comprising small groups of members, would be setup to look at selected topics. He mentioned normal arch determination, classification and orthodontic terminology as possible topics for the attention of these investigating committees. Thus, we can discern, in its first presidential address, some of the distinctive characteristics of the British Society for the Study of Orthodontics. Its constitution emulated the gentlemanly ethos of London patrician medicine, with its disdain for trade and its antipathy towards factional enthusiasm. It saw the future progress of orthodontics as being best achieved through the liberal ideals of the advancement of knowledge and the improvement of education, rather than by the pursuit of specialization and professional organization. Many of its founders

had links with the London teaching hospitals and/or with socially exclusive private practice, of the Harley Street variety. While not necessarily or wholly antipathetic to specialist practice, most of the leading members identified themselves, as we shall see, as generalists with a special interest in orthodontics, rather than as specialist practitioners, per se. The BSSO was, in other words, a distinctively British specialist body. The BSSO met seven or eight times a year. Each meeting usually consisted of the presentation of a long paper and several short papers or demonstrations. Sometimes, papers shared a related theme. Approximately twenty papers or demonstrations were subsequently published in the Society’s annual Transactions. Every year its president addressed the Society, and these addresses, also published in the Transactions, provide a valuable record of the opinions of the leading figures in British orthodontics, from 1907 onwards. It is evident from the Transactions that not all the members of the Society were content with the first president’s relatively relaxed attitude to the prospect of full-time practice. In 1910, Sim Wallace was elected president. His presidential address reaffirmed his commitment to generalism, in terms with which many of his colleagues in metropolitan medicine and dentistry would have been very familiar. The danger of specialization was, he argued, that it confined its practitioners to a narrow route, distorting the sense of proportion and limiting the large and liberal outlook, which should be characteristic of a learned profession. Such restriction of vision was stigmatized as the curse of specialism. Sim Wallace emphasized that the BSSO had been setup to serve the high ideal of the study of orthodontics and not merely to improve its practice or even its teaching. The implication was clear; full-time specialization, by depriving those interested in orthodontics of a broad intellectual outlook, would hinder rather than advance the development of their subject. But those presidents who concerned themselves with the quality of the British teaching of orthodontics frequently tended to a different view. This was particularly true of those who contrasted the situation in Britain with that in North America, to whose specialist institutions, as we have seen many British

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History of Orthodontics in Great Britain

prospective practitioners travelled to receive postgraduate training. For instance, in 1915, Frank Bouquet Bull, a leading member of the Society and a future president, firmly expressed his low opinion of the quality of the teaching of orthodontics in Britain. He attributed this deficiency to the fact that both lectures and clinical instruction in orthodontics were combined with dental surgery. With very few exceptions, the actual teaching was still carried out by generalists rather than specialist orthodontists. Bull pointed out that the prolonged nature of orthodontic treatment made it difficult to incorporate within the standard curricula of general dentistry. Most dental students undertook just over two years of clinical instruction but this was rarely long enough to follow a single orthodontic case to conclusion. Bull also believed that, until students had gained some basic knowledge of orthodontics, they could not fully appreciate its value. Thus many would-be practitioners, who might otherwise have been attracted to orthodontics, chose to remain with restorative dentistry. Bull recommended that orthodontic instruction should be separated from that of general dental surgery, and that it should be postponed until the second year of clinical studies. By this stage students would be better prepared to benefit from the teaching. In the second year, a period of three months should be set aside exclusively for orthodontics. Bull applauded the fact that the London Dental Hospital and the Birmingham Dental School had already implemented such a system. He suggested that independent Orthodontic Departments be created, each to be under the direction of someone with a particular interest in orthodontics, preferably assisted by a demonstrator and a specialist orthodontic house surgeon. This, he believed, would enable both patient management to be more effective, and the standard of teaching to be improved. Bull was not the only eminent British orthodontist concerned about these matters. In 1916, Bertram B Samuel gave a short paper entitled ‘Suggestions for the formation of a London orthodontic center’. As he saw it, orthodontics in England had two serious deficiencies, the dearth of treatment facilities for less well-off children and the absence of

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opportunities for postgraduate training. The establishment of a dedicated clinical center in London would meet both needs. Samuel proposed the Forsyth Institute in Boston as a model for orthodontic education in Britain. Bull’s and Samuel’s papers were both delivered in the second year of the First World War. The war imposed a hiatus on British dentistry as a whole and upon the activities and development of the BSSO in particular. Many dentists were heavily involved in the war effort, dealing with maxillofacial injuries. Orthodontic work was substantially curtailed. Even after peace returned, orthodontic treatment remained available to only a very small section of the population. The vast majority of the work was still carried out by dentists who also practised other branches of dental surgery. Even the teachers in the orthodontic departments of the dental schools were not necessarily orthodontic specialists in the North American sense, although they would certainly have had considerable expertise in the subject. However, the British Islands had, as we have already noted, begun to acquire their first full-time orthodontists. The case for and against specialization would continue to be discussed at the meetings of the Society for many years to come. But when JL Payne gave his presidential address in 1921, he seems to have considered that the principle of specialization had become accepted. S Spokes, president in the following year, judged that the development of orthodontics as a specialty had not been detrimental to the general dental practitioner but had benefited the profession as a whole. Throughout the 1920s and 1930s, the technical repertoire of the orthodontist continued to improve and expand. A notable advance was the introduction of stainless steel, which was employed in the construction of bands, arches and springs. Stainless steel was much cheaper and more clinically effective than the previous metal of choice, gold. However, considerably more skill was required to work the new material, stainless steel being difficult to weld. Friel was a major pioneer for the introduction of stainless steel, and several other British orthodontists contributed to the realization of its clinical potential. A further important innovation was the adoption, with modifications, by British

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History of Orthodontics

orthodontists of Angle’s pin and tube method of effecting tooth movement. This new procedure, together with other similar techniques, again enhanced clinical effectiveness, while demanding great precision in its construction and manipulation. In 1921, unregistered dental practice was finally made illegal in Britain. There was, however, a considerable shortage of dentists, and therefore little economic incentive for the ordinary dentist to diversify his practice. From the 1920s onwards, for a variety of reasons like awareness of lack of knowledge and equipment, legal considerations, ready availability of other remunerative work, many general practitioners were unwilling to undertake orthodontic work. And those who did perform such work tended to employ the cheaper and easier techniques. They were inclined, for instance, to favor removable appliances rather than the fixed ones, which were generally more precise and powerful but required more skill to fit and took up more chair time. Thus, the gap between the standards of orthodontic work carried out by the general practitioner and that undertaken by the full-time specialist, or taught within the orthodontic departments of the dental hospitals, continued to widen. British orthodontists, meanwhile, looked across the Atlantic and saw that, if the standard of the teaching of orthodontics in Britain was to match its American counterpart, then more specialized facilities and specialist teachers were required. Between the wars, calls for the setting up of a dedicated postgraduate center for orthodontics in London were regularly repeated. It was even suggested that it could be run under the auspices of the BSSO. Nothing came of these plans. However, in 1931, the Eastman Dental Clinic opened in London. This included a separate orthodontic department, which provided both affordable treatment and postgraduate orthodontic training. After the Second World War, the Eastman was incorporated into the British Postgraduate Medical Federation. Under the leadership of Clifford Ballard, its orthodontic department came to play a very important role in the further development of the subject in Britain. The establishment of the National Health Service in 1948 created the conditions for a great expansion in the provision of orthodontic care

in Britain. The principle of a state-funded health care system seems to have been enthusiastically endorsed by the leadership of the BSSO. In 1942, the Society set up a committee to examine the implications of the Beveridge Report for orthodontics. Faced with the prospect of a needdriven health service, free at the point of delivery and presumably including orthodontics in its comprehensive provision, the committee considered what sort of orthodontic care could be delivered to the general population, and by whom. In 1945, giving the first presidential address for six years, tellingly titled ‘Our opportunity’, Norman Gray welcomed the forthcoming peacetime expansion of health care as providing the prospect of raising the standards of British orthodontics and increasing the numbers of its practitioners. Noting that his predecessors had expressed differing opinions on the subject, Gray affirmed his belief that the time for specialization had finally arrived. He envisaged that the demand for orthodontic treatment would greatly increase once the financial obstacles that had excluded poorer children, were substantially removed. The challenge was to train sufficient numbers of specialists to meet the orthodontic needs of the population. In the same year, Friel also urged his fellow orthodontists to embrace the ideal of full-time specialization as the only way, as he saw it, to raise British orthodontic standards to the level that had been achieved in the United States. Friel deprecated the fact that much treatment in Britain was still undertaken by, as he put it, “skilled amateurs”. He argued that attempts to expand the provision of treatment without the introduction of adequate postgraduate education would simply prolong this unwelcome circumstance. His choice of terms is an indication of how far the discourse surrounding specialization in British dentistry had changed. Whereas previously the integration of orthodontics within the general practice of dentistry had been praised as conducive to a “sense of proportion” and a “large and liberal outlook”, it was now stigmatized as “amateurism”. The “curse of specialism” had evidently been lifted. The administrative structure that was chosen for the NHS imposed a rigid division between

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History of Orthodontics in Great Britain

hospital doctors and community-based general practitioners, an arrangement which was very conducive to the establishment of specialties. Gradually, many more consultants were recruited in virtually every branch of medicine and dentistry, including orthodontics. At the same time, the universities became more involved in orthodontic education. The first reader in orthodontics, Corisande Smyth, was appointed in 1951 at the Royal Dental Hospital School and the first professor, Clifford Ballard, at the Institute of Dental Surgery, University of London, in 1956. Other educational innovations were made. In 1949, the Faculty of Physicians and Surgeons of Glasgow awarded their first Diploma of Dental Orthopedics. The Royal College of Surgeons of England followed suit in 1954. By the mid-1950s, it was apparent, however, that the impact of the setting up the NHS on the process of specialization in orthodontics had been, to an extent, paradoxical. Many more specialists were being trained but, owing to demand for treatment vastly outstripping supply, more orthodontic work was being undertaken by general practitioners, often using limited means of treatment and under great time pressure. The membership of the BSSO continued to include a substantial number of general practitioners, reflecting the dual avenues of service provision. The changes that the founding of the NHS had set in train did not come fully into effect until the 1960s, when substantial number of orthodontic specialists were appointed, either as consultant in dental hospitals or with regional hospital boards. Oddly enough, however, this expansion of the specialty was to prove fatal for the BSSO. As noted above, its founders had conceived the BSSO rather as a learned society for the advancement of orthodontics than as a professional body to speak for orthodontists. This direction was taken partly to avoid the factionalism that had marked orthodontic societies in North America. However, the

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Society’s constitution was interpreted, by successive meetings of its Council, as precluding its involvement in any discussion or consultation remotely political, even when orthodontic service provision was involved. In 1919, the Parliamentary Health Committee invited the BSSO to send a report on its activities. The Secretary was instructed to decline, and reply that their activities did not extend to political affairs. When, in 1920, the Federation of Medical and Allied Societies invited the BSSO to affiliate, the Secretary replied that it was not empowered by its bye-laws to join. This fastidiousness also prevented the society from exercising its full influence during the planning and implementation of the NHS. It was initially reluctant, for instance, to become involved in the consideration of specialist titles within the service. The BSSO also declined to give any advice to the British Dental Association regarding charges for orthodontic appliances. In 1962, the Society was invited to submit evidence to the Standing Dental Advisory Committee, on hospital dental services. It again refused, expressing a wish not to become involved in administrative problems. This decision was eventually reversed, under pressure from the membership of the Society, but the damage had been done. Widespread dissatisfaction with the aloofness of the BSSO from matters relating to professional interest, particularly among members carrying out a significant amount of orthodontic treatment in practice as opposed to the hospital service, led to the formation of the British Association of Orthodontists in 1965. The BSSO lost a number of members to the new body, whose membership was restricted to those who were full-time, or nearly full-time orthodontic practitioners. The British Association sought actively to articulate its members’ point of view in the political arena. Eventually, in 1994, the BSSO lost its separate identity, merging with a number of other orthodontic groups to form the British Orthodontic Society.

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History of Orthodontics in Greece and Rome • Middle Ages (Fifth to Fifteenth – Etienne Bourdet Centuries) to the Eighteenth – John Hunter Century • European Pioneers of the Early – Matthaeus Gottfried Nineteenth Century Purmann – Joseph Fox The earliest description of irregularities of the teeth was given about 400 BC, by Hippocrates (ca 460– 377 BC). The first treatment of an irregular tooth was recorded by Celsus (25 BC–AD 50), a Roman writer, who said, “If a second tooth should happen to grow in children before the first has fallen out, that which ought to be shed is to be drawn out and the new one daily pushed toward its place by means of the finger until it arrives at its just proportion”. That might still be good advice, but children today do not need ancient history to tell them how to goad a high canine into place. Probably the first mechanical treatment was advocated by Pliny the Elder (AD 23–79), who suggested filing elongated teeth to bring them into proper alignment. This method remained in practice until the 1800s. MIDDLE AGES (FIFTH TO FIFTEENTH CENTURIES) TO THE EIGHTEENTH CENTURY Progress during the Middle Ages was nil. Dentistry entered a period of marked decline, as did all sciences. After the 16th century, considerable progress was made, although little was written of orthodontics during this period. In France, students of dentistry were admitted to a University, as early as 1580. The first mention

– – – – –

6

Joachim Lefoulon Christophe-François Delabarre JM Alexis Schange Friedrich Christoph Kneisel John Tomes

of practicing dentistry exclusively was made by Pierre Dionis (1658–1718). He called dentists “operators for the teeth” and stated that they could also open or widen the teeth when they are set too close together. Matthaeus Gottfried Purmann (1692) was the first to report taking wax impressions. In 1756, Phillip Pfaff used plaster of Paris impressions. Malocclusions were called “irregularities” of the teeth, and their correction was termed “regulating”. It remained for the enlightenment to reawaken the spirit of scientific thought necessary to advance dentistry and other disciplines. Beginning in the 18th century, the leading country in the field of dentistry was France. This was due, in large measure, to the efforts of one man: Pierre Fauchard (1678–1761 ) has been called the “Father of Orthodontia”. He was the first to remove dentistry from the bonds of empiricism and put it on a scientific foundation. In 1728, he published the first general work on dentistry, a two volume opus entitled The Surgeon Dentist: A Treatise on the Teeth. Fauchard described, but probably was not the first to use, the bandeau, and an expansion arch consisting of a horseshoe-shaped strip of precious metal to which the teeth were ligated. This became

History of Orthodontics in Greece and Rome

45

anatomy of the teeth and jaws. His text, The Natural History of the Human Teeth (1771), presented the first clear statement of orthopedic principles. He was the first to describe normal occlusion, to attempt to classify the teeth. He established the difference between teeth and bone and gave the teeth names like cuspidati and bicuspidati. He was the first to describe the growth of the jaws, not as a hypothesis, but as a sound scientific investigation. His findings have never been successfully challenged. EUROPEAN PIONEERS OF THE EARLY NINETEENTH CENTURY

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Joseph Fox (1776–1816)

Fig. 6.1: John Hunter

the basis for Angle’s E-arch, and even today its principles are used in unraveling a crowded dentition. He also “repositioned” teeth with a forceps, called “pelican” because of its resemblance to the beak of that bird, and ligated the tooth to its neighbors until healing took place. At that time, little attention was paid to anything other than the alignment of teeth and then almost exclusively to the maxilla. Etienne Bourdet (1722–1789) Fauchard’s bandeau was refined by Etienne Bourdet (1722–1789), dentist to the king of France. His was the first record of recommending serial extraction (1757) and of extracting premolars to relieve crowding. He was also the first to practice “lingual orthodontics”, expanding the arch from the lingual. There followed a long line of lingual appliances, including the jackscrew, the expansion plate, and, closer to our time, the lingual arch. John Hunter (1728–1793) Although he was not a dentist, John Hunter (Fig. 6.1) (1728–1793) made the greatest advances in dentistry of his time. An English anatomist and surgeon, Hunter took a particular interest in the

Joseph Fox (1776–1816), a student of Hunter, was another Englishman who made notable contributions to the budding science of orthodontics. He devoted four chapters of his book, the “Natural History and Diseases of the Human Teeth” (1814), to that topic. The first to classify malocclusion (1803), he was also one of the first to observe that the mandible grows mainly by distal extension beyond the molars, with little or no increase in the anterior region. According to Weinberger, Fox was the first to give explicit directions for correcting the irregularities of teeth. He was particularly interested in the judicious removal of deciduous teeth, treatment timing, and the use of bite blocks to open the bite. His other appliances included an expansion arch and a chin cup (about 1802). Joachim Lefoulon Joachim Lefoulon, a Frenchman, is probably best known for having given the science a name: orthodontosie (1841), which roughly translates into orthodontia. He was also the first to combine a labial arch with a lingual arch. In the area of etiology, he arrived at factors of an entirely different character from those of most authorities. These were based on biologic phenomena controlling the growth, form, and dimension of organs and tissues. Christophe-François Delabarre (1787–1862) Christophe-Fraçnois Delabarre (1787–1862; French) introduced the crib and the principle of the lever and the screw (1815). He separated crowded teeth by means of swelling threads or wooden wedges placed between them.

46

History of Orthodontics

JM Alexis Schange JM Alexis Schange (1807, French) in 1841 published the first work confined to orthodontics. He introduced a modification of the screw, the clamp band, and, in 1842, three years after the vulcanization process had been developed, rubber bands (actually, sections of rubber tubing). He also coined the term anchorage. Friedrich Christoph Kneisel (1797–1847) and John Tomes (1812–1895)

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Friedrich Christoph Kneisel (1797–1847, German), was the dentist to Prince Charles of

Prussia. He was the first to use plaster models to record malocclusion (1836). That same year, when he fitted his prognathic patient with a chin strap, he became the first to use a removable appliance. Kneisel wrote the first French and German treatises devoted exclusively to orthodontics. He and John Tomes (1812–1895, English) used various removable appliances to treat regularities of this. Tomes was also first to demonstrate bone resorption and apposition.

47

History of Dental Lasers and their Applications in Orthodontics

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History of Dental Lasers and their Applications in Orthodontics • All Laser Devices have Following Components – Laser Medium – Optical Cavity or Laser Tube – Clinicians can Control Several Variables of Laser Exposure • Properties of Laser Beam

• Focused versus Defocused Beam • Types of Laser • Lasers and Their Dental Applications • Current Clinical use of Dental Lasers

Light amplification by the stimulated emission of radiation. In 1956, American Physicist Townes first amplified microwave frequencies by the stimulated emission process and Maser (Microwave Amplification by Stimulated Emission of Radiation) came into the use. In 1959, Schawlow and Townes discussed extending the Maser principle to the optical portion of the electromagnetic field, laser. In 1960, Theodore Maiman, Scientist with the Hughes Aircraft Corporation developed first working laser device, that emitted a deep red colored beam from a ruby crystal. In 1964, Patel developed CO2 laser. In 1964, Geusic developed Nd: YAG Laser. Einstein, early in the 20th century described three possible mechanisms involving proton radiation. Absorption occurs when an atom in a lower energy level is raised to a higher energy level by absorbing a photon of energy. Spontaneous emission is the process in which an atom in a higher level decays to a staler lower energy level, releasing a photon. Stimulated emission occurs when an atom already in the excited state decays to a stale state, after interaction with a photon corresponding

7

• Laser use in Dentistry • Laser Classification • Applications of Lasers in Orthodontics • Laser Safety • Precautionary Measures

exactly to the absorption energy. This result in two photons of light emitted with the same wavelength, with temporal and spatial coordination. Using Einstein theory laser is produced. ALL LASER DEVICES HAVE FOLLOWING COMPONENTS Laser Medium This can be solid, liquid or gas. This determines the wavelength of emitted light from the laser. Optical Cavity or Laser Tube Having two mirrors, one fully reflective and other partially transmissive which are located at either end of the optical cavity. An external mechanical, chemical or optical power source which excites the atoms in the laser medium to higher energy levels. Atoms in excited state spontaneously emit photons of light which bounce back and forth between the two mirrors in the laser tube striking other atoms and causing more stimulated emissions. Photons of energy of the same wavelength and frequency escape through the transmissive mirrors and form a laser beam.

48

History of Orthodontics

Clinicians can Control Several Variables of Laser Exposure Wavelength • Determines the quality or type of reaction between laser and tissue • It is determined by composition and structure of active medium • It in turn, predominantly influences whether absorption occurs.

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Power

effectively after reflection, there is little danger of damage to other parts of the mouth. It limits the amount of energy that enters the tissues. Scattering When beam is scattered within the tissue. When light energy bounces from molecule to molecule within the tissue. High absorption minimizes scattering. Scattering distributes the energy over a large volume of tissue, dissipating the thermal effects.

• Instant measure of energy output. • Optical properties of the tissue including its water content. • Wave from described the manner in which laser power is delivered over time. It can be: – Continuous: They deliver the power output at a constant level over a prolonged period of time, generally any time span exceeding 1 sec, e.g. CO2 laser. – Chopped/gated beam: It is similar to continuous one except beam is alternatively released and interrupted by a shutter mechanism; this chopping can be either a single chop or series of timed chops. • Pulsed lasers: In this, energy is emitted in short bursts according to a set repetitive series of pulses. Between the pulses no laser energy is emitted. • Because the amount of heat generated during the procedure translates directly into the amount of collateral damage and thus postoperative discomfort – it is generally recommended that the laser be used at a low setting and in pulsed mode for soft tissue procedures.

Transmission

PROPERTIES OF LASER BEAM

The principal effect of laser energy is photothermal: This thermal effect of laser energy on tissue depends on degree of temperature rise and corresponding reaction of interstitial and intracellular water as the laser energy is absorbed, heating occurs. Hyperthermia occurs when tissue is elevated above normal temperature but is not destroyed at temperature of approximately 60oC. Proteins begin to denature without any vaporization of the underlying tissue. Coagulation refers to the irreversible damage

Coherent: All the photon of light are in spatial and temporal coherence. Mono Chromaticity: Of one particular wavelength. Collimation: No divergence of the beam Laser beam interaction with tissue: Laser beam and tissue interact in four ways: Reflection A reflected light bounces off the tissue surface and is directed toward as energy dissipates so

Light energy can also travel beyond a given tissue boundary. This is called transmission. Transmission irradiates surrounding tissue and must be quantified. Absorption Refers to how far beam is absorbed within the tissue or whether it is absorbed at all. FOCUSED VERSUS DEFOCUSED BEAM Laser beam can be focused through a lens to achieve a converging beam, which increases in intensity to form a focal spot, the most intense part of the beam. This focused beam cuts the tissue. In defocused beam, intensity is less, beam diverges and power decreases. So a larger circumferential area of the beam hits the tissue surface causing ablation of the tissue. The laser tip cuts soft tissue through ‘ablation’ of tissue. This means that the cellular temperature is raised rapidly through the absorption of laser energy by the melanin in the cells and the cells virtually explode. This characteristic is useful in both cutting and contouring gingival tissues.

History of Dental Lasers and their Applications in Orthodontics

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to tissue, congealing liquid into a soft semi solid mass. Soft tissue edges can be ‘welded’ together with a uniform heating to 70–80oC where there is adherence of the layers because of stickiness due to collagen molecule. When the target tissue containing water is elevated to temperature of 100oC, vaporization of water occurs, process is called ablation. If the tissue temperature is raised to about 200 oC, it is dehydrated and then burned in presence of air with carbon as end product. If laser energy continues to be applied, the surface carbonized layer absorbs the incident beam, becomes a heat sink and preventing normal tissue ablation. The heat conduction causes a collateral thermal trauma to a wide area.

•

•

• •

TYPES OF LASER Soft Lasers They provide (a thermal) low energy at wavelengths believed to stimulate circulation and cellular activity. Used to promote healing and reduce inflammation, edema and pain, e.g. diode laser. Hard Lasers Have been used for surgical applications, e.g., CO2 laser.Lasers are named according to the laser medium employed: • Solid state—e.g. ruby laser, neodymium laser • Gas state—e.g. argon laser, CO2 laser • Semiconductor state—e.g. diode laser CO2 Laser • CO2 laser were first developed by Patel in 1964. • Have a wavelength of 10.6 microns. • Since the beams of this laser fall into the far infrared range on the spectrum, they are not visible. These lasers often use a quartz-fiber incorporating a 630 nm (Red) coaxial heliumneon laser into the device to act as an aiming beam and thus facilitate use. • It received safety clearance by the U.S. Food and drug administration for use in soft tissue surgery in 1976. • CO2 lasers have an affinity for wet tissues regardless of tissue color. Tissue pigment does not affect the performance of CO2 laser. • CO2 laser wavelength is readily absorbed by water as soft tissue is 75%–90% water, about

•

49

98% of the energy is converted to heat and absorbed at the tissue surface with very little scatter or penetration (0.2 to 0.3 mm). CO2 lasers reflect off mirrors, allowing access to difficult areas. Unfortunately, they reflect off dental instruments making accidental reflection to non target tissue causing concern. CO2 laser is absorbed by optical fibers and lack of fiber optic delivery system make CO2 laser difficult for allows the beam to be delivered through a flexible tube giving access to all areas of oral cavity. CO2 laser works in no contact mode with the tissue and no tactile feedback occurs. Depth of laser incision is proportional to the power and duration of exposure. Laser soft tissue surgery is performed with power 5–15 watts in either pulsed for continuous mode. It is the fastest laser in removing tissue for oral use.

Nd:YAG Laser • Developed by Geusic in 1964. Refers to neodymium: yttrium-aluminium-garnet, a crystal of yttrium-aluminum-garnet doped with neodymium. Lasers are in infrared range, 1.06 microns wavelength and cannot be seen. These lasers use a red helium-neon laser for aiming. • It is not well-absorbed by water but is partially absorbed by hemoglobin and melanin. It has an affinity for pigmented tissues. • ND: YAG laser light transmits through water and penetrates wet tissue more deeply than CO2 laser. Heat build-up, scatter and depth of tissue penetration by the beam remain major considerations. • They can be delivered by fiber optic technology. Their access into the mouth is unlimited. • Laser work in either contact or noncontact mode when working on tissue contact mode is recommended by using pulsed rate, a coated sapphire tip or combination of water and air cooling in contact mode, penetration depth can be reduced to a point equal to CO2 . • Contact tip provide surgeon a tactile feedback. • For dental use, it can deliver power up to three watts in either pulsed or nonpulsed mode. Erbium– YAG Laser In 1997, FDA saftey clearance for use on hard tissues such as enamel, cementum and bone.

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50

History of Orthodontics

It consists of two wavelengths: • Erbium: yttrium-aluminum-garnet laser at 2940 nm wavelength. • Erbium: chromium-yttrium-scandiumgallium-garnet at 2780 nm wavelength. • These lasers are delivered by a special optical fiber or hollow wave guide technology; operate in pulsed mode with an accompanying helium neon laser as an aiming beam, since wavelength is invisible. • Wavelength 2940 nm, is ideal for absorption by hydroxyapatite and water making it efficient in ablating enamel and dentin. • It is essential to use a water spray to wet the surface during laser radiation to achieve maximum efficiency of tissue removal with minimal heat generation. • They have highest absorption in water and have shallow penetration into soft tissue of any wavelength. • They can be used to cut soft tissue precisely due to high water content. • These lasers are well-absorbed by hard tissues; the surgeon must protect adjacent tooth structures in the operative field.

•

• • •

•

•

•

using some combination of aluminum, indium, gallium and arsenic. Wavelength 812 nm for active mediumaluminum to 980 nm for active medium-indium, placing them at the beginning of near infrared portion of invisible nonionizing spectrum. The laser energy is absorbed by pigmentation in the soft tissues and this makes the diode laser an excellent haemostatic agent. As it is used in contact mode, it provides tactile feedback during surgical procedure. It can be delivered through a flexible quartz fiber optic hand piece in continuous wave and gated pulses modes and is used in contact with soft tissues for surgery or out of contact for deeper coagulation. These lasers are poorly absorbed by tooth structure so that soft tissue surgery can be safely performed in close proximity to enamel, dentin and cementum. It can often be used without anesthesia to perform very precise anterior soft tissue esthetic surgery or surgery in other areas of the mouth without bleeding or discomfort. It is an excellent soft tissue surgical laser.

Argon Lasers

LASERS AND THEIR DENTAL APPLICATIONS

• Argon laser light has 2 primary wavelengths, 488 and 514.5 nm. These manifest as blue and green visible light. • Argon is highly absorbed by hemoglobin, strongly absorbed by melanin and poorly absorbed by water. • It is absorbed well by oral soft tissue and provides excellent hemostasis. • May be well suited for selective destruction of blood clots and hemangiomas with minimal damage to adjacent tissues. • It is not absorbed by hard tissue; no particular care is needed to protect teeth during laser surgery. • Travel fiber optically. • Either an attenuated argon or helium neon red beam can serve as an aiming beam. • They have the ability to cure composite resins.

Carbon Dioxide Laser Clinical applications removal of soft tissue by ablation. Recommended for gingivectomy, frenectomy and excision of soft tissue pathology (both benign and malignant). Also used for laser de-epithelization of flaps during and after surgery. Precautions avoid hard tissue contact by laser emission, especially tooth structure. Use expanded margins when performing a laser excisional biopsy to prevent fulguration of diagnostic areas. Tissue penetration from laser irradiation will be approximately 0.5 mm deep, depending on power density; very little heat damage occurs below visual depth of wound. Neodymium:YAG Laser

Diode Lasers

Clinical applications: Removal of soft tissue by ablation. Recommended for gingivectomy, frenectomy and excision of soft tissue pathology especially hemorrhage lesions. Also used for laser subgingival curettage procedure.

• Diode is a solid active medium laser, manufactured from semiconductor crystals

Precautions: Avoid hard tissue contact by laser. Same precautions as listed for CO2 laser. Tissue

51

History of Dental Lasers and their Applications in Orthodontics

penetration from laser may cause thermal damage 2 to 4 mm below surface wound causing underlying hard tissue damage. Diode Laser

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Clinical applications: Removal of soft tissue by ablation. It is recommended for gingivectomy, frenectomy and excision of soft tissue pathology, especially hemorrhagic lesions. Similar applications as Nd:YAG laser. Used for laserassisted subgingival curettage and periodontal pocket disinfection. Precautions: Avoid contact with hard tissues. May damage root cementum and bone during subgingival curettage. Tissue penetration is less than comparable Nd:YAG effects, with potential for heat damage to underlying bone reduced. Erbium:TAG Laser Clinical applications: Cavity preparation of incipient caries. Root preparation similar to acid etching following root planning. It has not been studied extensively for soft tissue applications. Precautions: Must use adequate water spray when cutting hard tissues with laser. Minimal heat damage reported when used on dental hard tissue at appropriate power densities.

CURRENT CLINICAL USE OF DENTAL LASERS Application

CO2 Nd:YAG Ar

Coagulation Hemostasis Frenectomy Gingivectomy Gingivoplasty Vestibuloplasty Incisional/excisional biopsy Implant recovery Removal of fibroma Epulis Hyperplasia Malignant lesions Oral lesion therapy Caries removal Primary incisions Gingival retraction Aphthous ulcer/oral lesion therapy Root desensitization Curing light-activated resins Interproximal decay detection

X X X X X X X X X X X X X X X X

X X X X X X X X X X X

X X

X X

X X X

X X X X X X X X X X X X X X X X X X

LASER USE IN DENTISTRY Periodontics Initial (nonsurgical) pocket therapy Nonosseous Gingival Surgery

Potential Soft and Hard Tissue Applications of Laser in Dentistry Soft tissue applications:Incise, excise, remove or biopsy tumors and lesions such as fibromas, papillomas and epulides. Vaporize excess tissues, as in gingivoplastry, gingivectomy and maxillary or lingual frenectomy. Remove or reduce hyperplastic tissues. Remove and control hemorrhaging or vascular lesions such as hemangiomas. Hard Tissue Applications • Vaporize carious lesions. • Desensitize exposed root surfaces. • Endodontically: vaporize organic tissue, glaze canal wall surfaces and fuse an apical plug with the potential to resist fluid leakage. • Roughen tooth surfaces, in lieu of acid etching, in preparation for bonding procedures. • Preventively, to treat enamel, arrest demineralization and promote remineralization. • Debond ceramic orthodontic brackets.

• Frenectomy • Gingivectomy • Graft Periodontal Regeneration Surgery • De-epithelization • Removal of granulomatous tissue • Osseous recon touring Fixed Prosthetics/Cosmetics • Crown lengthening/soft tissue management around abutments • Osseous crown lengthening • Troughing • Formation of ovate pontic sites • Altered passive eruption management • Modification of sift tissue around laminates • Bleaching Implantology • Second-stage recovery • Peri-implantitis

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History of Orthodontics

Removable Prosthetics • • • • • •

Epulis fissurate Denture stomatitis Residual ridge modification Tuberosity reduction Torus reduction Soft tissue modification

Pediatrics/Orthodontics • Exposure of teeth • Soft tissue management of orthodontic patients

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Oral Surgery/Oral Medicine/Oral Pathology • • • •

Biopsy Operculectomy Apicoectomy Oral soft tissue pathologies

Operative Dentistry • Deciduous teeth • Permanent teeth Advantages of Lasers in Soft Tissue Surgery 1. Laser cut is more precise in tissue removal with greater visibility since it seals off blood vessels and lymphatic leaving a clear, dry field. 2. Laser sterilizes as it cuts to reduce the risk of blood borne transmission of disease. 3. Minimal pain and swelling has been reported after surgery. 4. Less postoperative infection has been reported, since the wound is sealed with a biological dressing. 5. There is less wound contraction during healing and mucosal tissue does not scar. 6. Less damage occurs to adjacent normal tissue. 7. Access is better to parts of oral cavity, especially the mandibular, lingual, retromolar and parapharyngeal areas. 8. Better patient acceptance, less operative time and fewer postoperative adverse squeal. 9. In treatment medically compromised patient HIV +ve and mentally retarded patients. 10. Lasers can be adjusted to cut, vaporize or coagulate tissue, they offer greater versatility than conventional instruments. 11. Pain is reduced to absent 90% of time due to the sealing of nerve fibers.

Laser Safety 1. Precautions for patients and dental staff during laser procedures to protect non-target tissues particularly the eyes from stray beams. 2. Reflective surfaces such as instruments, mirror and even polished restorations have potential to redirect laser energy. 3. Matte instruments and protective eye glasses for patients and staff – Green safety glass– Nd: YAG laser – Amber colored glasses– Argon laser – Clear glasses– CO2 laser. 4. Patients eyes should be covered with moist 2 x 2 gauze pads. 5. Non target oral tissues should be shielded with wet gauze, packs. 6. Laser plume created when tissue vaporizes should be considered infectious. Use of an appropriate evacuation system to draw off and filter the plume is essential. 7. Extreme caution must be used when operating laser in vicinity of explosive gases such as anesthetics. 8. Staff who will operate a laser or attend laser procedures must be thoroughly trained to respect this powerful tool and follow standard protocol. 9. At some operating powers of CO2 laser can cause damage to dental hard structures, clinicians have emphasized need for an adequate shield such as flat bladed instrument or silver foil between gingival and teeth, so that beam will strike the instrument rather than the tooth. LASER CLASSIFICATION They are based chiefly on the potential of the primary laser beam or reflected beam to cause biologic damage to the eyes or skin. Higher the classification number, greater the potential hazard. Class I • Lasers working under normal operating conditions do not pose a health hazard. • Devices are totally enclosed, beam does not exit housing, e.g. CD player. Class II • Lasers emit only visible light with lower power output and do not normally pose a hazard

History of Dental Lasers and their Applications in Orthodontics

because of normal human blinking and aversion reactions, e.g. supermarket bar code scanner. Two Subclasses • Class II A: Hazardous when directly viewed for longer than 1000 sec. • Class II B: Has a dangerous viewing time of one-fourth of a sec., which is the length of time of an ordinary blinking, reflected. Class III a: Lasers

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• Lasers can emit any wavelength and have output power less than 0.5W of visible light. It does not harm the unprotected eye. • These labels have a caution label on them. Class III b • These lasers can produce a hazard to the unprotected eye if viewed directly or viewed from reflective light for any duration. • These lasers will not cause reflective hazards when using matted surfaces and do not normally produce fire hazards.

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Frenectomy by Laser As permanent maxillary central incisors erupt in the oral cavity, the labial frenum shifts apically, in some instances frenum may persist even after complete eruption of permanent maxillary central incisors termed as high labial frenum attachment. Abnormal frenum attachment prevents approximation of maxillary central incisors resulting in midline diastema. Frenectomy by laser (Fig. 7.2A) prevents recurrence and facilitates diastema closure. Patient acceptance with laser application is very high even in condition like tongue tie, as it facilitates healing, reduces the discomfort and no sutures are required (Fig. 7.2B). Reduction of Pain in Orthodontic Patient by Application of Laser Procedures like separators placement and banding procedures are considered to be painful in the whole course of orthodontic treatment.

Class IV • Hazardous for direct viewing and may produce hazardous diffuse reflections. • Power output greater than 0.5W measured in continuous or pulsed emission. • May ignite flammable objects and may create hazardous airborne contaminants. • Lasers used in dentistry: Class III b or class IV.

A

APPLICATIONS OF LASERS IN ORTHODONTICS Lasers have wide range of applications in dentistry. In this chapter only few important applications in orthodontics are discussed. Exposure of Impacted Tooth by Laser Canine is the most commonly impacted tooth in the anterior segment of the dental arches due to arch length—tooth material discrepancy, this may delay the progress of orthodontic treatment. Exposure of impacted tooth by laser facilitates accessibility and decreases the risk of bond failure (Figs 7.1A and B).

B

Figs 7.1A and B: Exposure of impacted tooth by laser (A) Exposure of impacted canine with laser; (B) Exposed canine is bonded and ligated to the arch wire

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54

History of Orthodontics

A(i)

A(ii)

B(i)

B(ii)

B(iii) Figs 7.2A and B: (A) Frenectomy by laser (i) Abnormal frenum attachment prevents approximation of maxillary central incisors resulting in midline diastema. (ii) Frenectomy by laser followed by active fixed mechanotherapy; (B) Tongue tie excision by laser (i) Tongue tie (ii) Excised tongue tie with laser (iii) Nearly completion of healing

Studies proved that the application of laser in patient with separators reduces the level of pain threshold. Application of Laser in Bonding Orthodontic Bracket Nowadays laser is used in curing of orthodontic bracket in bonding procedure. Curing of orthodontic bracket by laser takes approximately (3–5) seconds. It reduces the chair time and

increases the efficiency of bonding especially in uncooperative and very apprehensive patients. Laser Ablation of Surface Enamel for Orthodontic Bracket Placement Laser ablation has been proposed as an alternative method to acid etching. Common problems during orthodontic treatment after acid etching the enamel are demineralization and susceptibility to caries around brackets. Er:YAG laser ablation might

History of Dental Lasers and their Applications in Orthodontics

overcome this drawback while offering other benefits like reduction in clinical time, good moisture control during bonding and bond strength similar to that of acid etching. Gaining Access for Bracket Placement on Partially Erupted Teeth

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In certain cases, the orthodontic treatment is often prolonged due to incomplete or delayed eruption of the tooth, because the labial surface is covered by the gingival, which hinders the bracket

55

placement. In such cases either we have to wait until tooth erupts completely till the occlusal plane or refer the patient to periodontist for removal of tissue to gain access for bracket placement. Either choice could add significant time to the overall treatment. Exposure of teeth by laser facilitates accessibility and decreases the risk of bond failure. The patient in the Figures 7.3A to F, the progress of orthodontic treatment was delayed by thick mucosal barrier covering the left permanent central incisor. The

A

B

C

D

E

F

Figs 7.3A to F: Gaining access for bracket placement on partially erupted teeth (A) Mucosal barrier covering the permanent central incisor and preventing it from erupting. (B) Exposure of permanent central incisor by laser; (C) Begg bracket bonded on the exposed permanent central incisor and ligated to the arch wire;. (D and E) Nearing the alignment of permanent central incisor; (F) Almost the permanent central incisor has brought into alignment

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History of Orthodontics

tooth is exposed by laser and then bracket is bonded, thereby bringing it into alignment. Removal of Redundant Gingival Tissue by Laser during Orthodontic Treatment Poor oral hygiene in orthodontic patient results in swollen gingival tissue, which delays the orthodontic treatment. Laser can be used in the removal of redundant tissue, which fastens the progress of orthodontic treatment.

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Management of Aphthous Ulcer by Laser during Orthodontic Treatment One of the most uncomfortable experiences for orthodontic patients is the formation of aphthous ulcer. Application of laser for aphthous ulcer (Figs 7.4A and B) helps in reducing the pain and also promotes healing. Healing usually takes place in a day. Laser irradiates the surface nerve ending and eliminates the painful stimuli.

Removal of Operculae on Second Molar by Laser In some cases, second permanent molar is also bonded to provide additional anchorage and to avoid excessive repair visits. If second permanent molar is the last tooth in the arch, it is often associated with operculum. Presence of operculum hinders the band placement. Removal of operculum by soft tissue laser facilitates the exposure of tooth, later providing accessibility for band placement (Figs 7.5A and B). Use of Laser in Controlling the Growth of Facial Structure Orthodontics is one of the important domains with interests in human growth and development with the advent of “high energy lasers” (that are not deleterious), it may prove that research could lead to the use of lasers in the practice of orthodontics “High energy lasers” might be applied to

A

A

B

B

Figs 7.4A and B: Management of aphthous ulcer by laser (A) Aphthous ulcer on the lateral borer of the tongue; (B) Healing of the aphthous ulcer followed by laser therapy

Figs 7.5A and B: Removal of operculae on second molar by laser (A) Showing operculum in relation to second molar; (B) Operculum has been removed with the laser

History of Dental Lasers and their Applications in Orthodontics

manipulation of human facial growth leading to new methods to cope with problems either overgrowth or undergrowth. Caries Control during Orthodontic Treatment Development/occurrence of dental caries is not an uncommon complication in orthodontic patient especially around brackets and in interproximal area after proximal stripping of teeth to gain space. Studies have demonstrated that Nd:YAG laser irradiation with (APF) fluoride application acts as an effective method of caries control during orthodontic treatment.

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Tooth Whitening by Laser Laser can be used for removal of intrinsic stains (Figs 7.6A and B) and or postoperative tooth whitening to brighten the smile.

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Depigmentation of Gingiva by Laser Gingival pigmentation gives unesthetic appearance, especially during smiling and seen more commonly in black race groups. Lasers can be used to remove gingival pigmentation and helps in restoring the lost esthetics (Figs 7.7A and B). Crown Lengthening Procedure by Laser (Figs 7.8A and B) An excellent application of crown lengthening is when a canine is substituted for a congenitally missing lateral incisor. When first premolar is the canine position, its crown height looks too short. Some clinicians recommend intrusion of the premolar and placement of a laminate veneer to restore length. Another option, however is to lengthen the premolar crown by laser gingivectomy. Debonding of Brackets by Laser Debonding of brackets is one of the most important procedures carried out after the active fixed mechanotherapy. Debonding of ceramic bracket is difficult and often results in fracture of brackets. Studies proved that application of lasers in debonding of brackets not only helps in

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A

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B Figs 7.6A and B: Tooth whitening by laser (A) Before; (B) After

Figs 7.7A and B: Depigmentation of gingiva by laser (A) Before; (B) After

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History of Orthodontics

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A

Fig. 7.9: Always put on the protective eye glasses prior to the application of lasers. It is recommended to use only laser specific protective eye glasses B Figs 7.8A and B: Crown lengthening procedure by laser (A) Before; (B) After

debonding of metal brackets but also makes easy of ceramic bracket debonding and prevents fracture of enamel. LASER SAFETY Lasers are excellent tools, but they also bear a very high risk for high risk for severe injury and damage. Laser radiation mainly endangers eyes, the retina cornea and the lens are concerned. Damage of the retina usually is permanent. Thus just a slight carelessness can impair your vision. The second affected organ is skin although it is much less sensitive than eyes and damages occur only at high energies. Hence, the high risks require suitable protective measures; their strict observation is the responsibility of the clinician and the management.

PRECAUTIONARY MEASURES Following are the important precautionary measure prior to the handling and clinical applications of Lasers; 1. Always put on the protective eye glasses prior to the application of lasers. It is recommended to use only laser specific protective eye glasses (Fig. 7.9). 2. Make sure the door of the operatory room should always be closed. 3. Use of nonreflective instrument is recommended to avoid indirect hazard. 4. Cover the endotracheal tube with wet gauge piece or use special stainless steel tube to avoid combustion of anesthetic gases by laser beam 5. Use of high vacuum suction or smoke evacuator for evacuations of toxic gases.

Angle’s Contribution to the Faculty of Orthodontics For Personal Use Only Library Of School Of Dentistry.Tums

• Edward Hartley Angle –Dental Graduation • Angle’s Dental Practice at Towanda • Edward Hartley Angle’s Professional Teaching Career

• Edward Hartley Angle‘s School of Orthodontics at Pasadena, California USA • Appliance Contribution by Edward H Angle – E-arch Appliance – Pin and Tube Appliance – Ribbon Arch Appliance

Edward H Angle is one of the most dominant, dynamic, and influential figures in the specialty of orthodontics. He separated orthodontics from the other branches of dentistry. Edward H Angle’s early years reflect elements of a classic American success story of his era: a fiercely determined young man of no remarkable heritage serendipitously finding his considerable aptitudes and blazing trails in pursuit of his visionary goals. At various times in his letters, he expressed his admiration for a pantheon of archetypes with traits akin to his own, such as the indomitable messenger in “A Message to Garcia”, the popular, inspirational short story (1899) by Elbert Hubbard, which became required reading for Angle’s students. Samuel L Clemens (Mark Twain), poetstoryteller James Whitcomb Riley, George Catlin, Benjamin Franklin, and Rembrandt van Rijn were among his favorite heroes. All were creative achievers and resolute individualists of humble birth and with great connection to everyday people. Dr Angle never forgot his farm-boy life in northeastern Pennsylvania that helped shape

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– Edgewise Appliance • Angle’s Orthodontic Material Invention • Case-Angle Controversy • Criticisms • Edward H Angle’s Publications and Presentations

many of his qualities and quirks in adulthood. From the southern boundary of District no. 1 of Herrick Township in Bradford County, you could almost see the deep, winding chasm of the Susquehanna River valley. This area was nicknamed “Ballibay” in the 1820s by the new settlers from the town of Ballybay, County Monaghan, Ireland. Edward Hartley Angle was born here June 1, 1855 in a modest, white woodframed house near the crest of a hill on his father’s 200-acre dairy farm (Fig. 8.1). He is recorded in the 1860 Bradford County census book as “Hartly”, the fifth of six children, and third son, to Philip Casebeer Angle and Isabel Erskine Angle. His father’s roots were primarily Dutch and his mother was born in Ireland. From childhood, he was called “Hart” by his family and close friends. The Angles had a seventh child, William, a bright lad, who died of illness at age 11. Teen-aged Hart was hurt terribly by the loss of his younger brother Willie, his favorite sibling. Hart showed no enthusiasm in school or on the farm, to the utter dismay of his unsympathetic father. He was always behind in his learning, especially mathematics, and he

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History of Orthodontics

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Fig. 8.1: Angle’s white wood-framed house where he was born

avoided farm work as much as he could. He was a natural tinkerer, a whittler, a maker of things. In reminiscences, his wife Anna told about his heavily scarred knees, lifetime reminders of boyhood knife slips. When his father needed a more efficient hay rake, 11-year-old Hart invented one. However, he did not get much appreciation for the new machine, and soon someone else applied for and was awarded the patent for Hart’s instinctively clever work. It was an early lesson in life’s unfairness that the sensitive boy probably long remembered. In Angle’s letters, we find a man who cherished his boyhood friendships throughout life. He never lost contact with some of his Herrick chums, like Cyrus Camp, Guy Fuller, and Jerry Sanger. His correspondence with them is often in the playful tones of a kid still horsing around the farmyard. Angle peppered his letters to his hometown friends with monikers concocted from the names of town fathers with whom the boys occasionally skirted trouble. “Cy” Camp was sometimes referred to as “J. Rufus Avery” or “Gideon Squares” in Hart’s jocular letters to him. Angle also showed his selfdeprecating humor to old, dear friends in the variety of comical aliases he used in signing his letters: Alexander J Horatio, Alonzo Revellen, Big Foot, Colossus Doc the Great, Flat-nosed Hart, Little Harty Angle, Old Man Friar, Uncle Reuben, and sometimes simply the geometric notation“. EDWARD HARTLEY ANGLE—DENTAL GRADUATION In 1874, at age 18, Edward Hartley Angle was introduced to dentistry with coaxing from his

understanding mother Isabel. Recognizing his nascent mechanical skills, she secured a position for Hart with a dentist in nearby Herrick, as an office apprentice. He got on well in dentistry—it appealed instantly to his keen manual and visual senses, his love of tools and his need for orderliness. Two years later, he applied to dental colleges. His scratchy, brief letter of inquiry dated September 6, 1876, to the Baltimore Dental College is the earliest document extant from his hand. In it, he touted his proficiencies in the indispensable texts of the day: Harris’s The Principles and Practice of Dental Surgery (1863) and Piggot’s Chemistry and Metallurgy, as Applied to the Study and Practice of Dental Surgery (1854). Although his English constructions and spelling were rather crude for a schooled 21-year-old, young Angle exuded the restless confidence that would mark his entire adult life and would win him success in many adventures to come. He was invited to enroll at Pennsylvania College of Dental Surgery in Philadelphia for their DDS program, then arranged in two 6-month terms spaced over a nominal 2 years and located in a building at the northwest corner of Twelfth and Filbert Streets. Angle alluded to his college experiences years later in friendly letters with classmates EL Townsend and Charles J Tibbets. In 1895, Angle completed his MD degree from Marion Sims College. ANGLE‘S DENTAL PRACTICE AT TOWANDA After dental school graduation in 1878, Edward Angle went to the Bradford County seat, Towanda, and set-up a general practice of mechanical dentistry in the center of town. He became a boarder in the home of Towanda’s leading physician, Dr David Shepard Pratt, a good strategic decision for the bright new dentist in town. Young Dr Angle advertised in local newspapers, such as The Sullivan Review, and appeared to be rapidly successful. Here in his leisure as an unmarried young professional, Angle developed his first interests in mechanisms for tooth alignment or “regulation”, considered the main purpose for moving teeth at that time. In Towanda, Angle experienced declining health that was to plague him on and off for the

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Angle’s Contribution to the Faculty of Orthodontics

rest of his life. He was diagnosed with pleural pneumonia. Today, we may understand this chronic respiratory condition as a consequence of tuberculosis. One popular treatment of the day was for the sufferer to move to fresher, cleaner air—to a pristine resort set up for this purpose or to the mountains or the desert. Angle formed special bonds throughout his career with those who shared the same affliction, former student Albert “Leaf” Ketcham being the most prominent among them. After 3 years of dental practice in Towanda, in the spring of 1881, 26-year-old Dr Angle abandoned dentistry and took a train to Minneapolis, Minnesota, on a physician’s advice, in search of better health. Within a few months, his condition improved and, with his recovery, came renewed confidence and resolves to make something of himself. For his health’s sake, Angle was considering permanent retirement from dentistry in favor of work that was less confining and more outdoors. In Minneapolis, he heard that sheep farming in Montana was where the “big money” could be made. In the fall, he returned briefly to Pennsylvania to entice some of his old farm buddies from Herrick to join him in setting up a lucrative sheep-raising business. They signed on excitedly, and the lot of his Ballibay cronies—including his older brother Mahlon and close friend Cy Camp—traveled with the freewheeling Hart to the fresh air of the Montana wilderness in search of their “pot of gold” (Fig. 8.2). Angle invested all his savings into their sheep-farming venture, all to be undone by the great blizzard of 1882, a record-breaking deep freeze that killed off the entire herd. The emptyhanded boys from Ballibay sullenly returned to Pennsylvania, except for Hart. A defeated Angle, feeling physically better but mentally depleted, hobbled in to Minneapolis by mid-1882 looking for work—again in dentistry. EDWARD HARTLEY ANGLE’S PROFESSIONAL TEACHING CAREER Edward Hartley Angle got back into general dental practice and soon resumed the creative thinking and tinkering with tooth-regulating appliances that he began in Towanda. Within a couple of years, Angle inquired at the Dental

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Fig. 8.2: Edward Hartley Angle

Department of the Minnesota Hospital College in Minneapolis regarding faculty employment. Impressed with what he had to offer, the college administrators tailored a position to suit his skills and their needs. In 1886, 31-year-old Edward Angle was appointed a professor of histology and lecturer on comparative anatomy and orthodontia. A few years later, after the Hospital College merged into the University of Minnesota, he was elevated to professor of orthodontia, a rare position in those days when orthodontia was a neglected part of the prosthetics department at dental colleges. At the same time, he quickly ascended through the ranks to become president of the Minneapolis City Dental Society in 1888. He also was able to maintain his small private dental office, where he experimented more and more with novel approaches in orthodontic mechanisms. In sum, through his resilience, industriousness, and good fortune, Angle seemed to have landed on his feet

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History of Orthodontics

psychologically and financially from the Montana get-rich-quick debacle a few years earlier. His big break came in 1887 when Angle was permitted on the speaking program of the Ninth International Medical Congress convened in Washington, DC. On the fourth day of this important Congress, Thursday, September 8, 1887, the section on “Dental and Oral Surgery” was called to order at 11 AM in the Universalist Church at the corner of 13th and L Streets. Thirtytwo-year-old Dr Angle was the youngest of the session’s speakers and was scheduled last on the day’s program. Two prominent authorities on orthodontics directly preceded Angle: Clark Goddard, professor at University of California, San Francisco, and Eugene Talbot, textbook writer and professor from Chicago. A confident Edward Angle presented his talk, entitled “Notes on Orthodontia with a New System of Regulation and Retention”, using lantern slides—a relatively new visual aid for lecturing. He demonstrated his classification of tooth movements and his novel orthodontic devices, such as piano wire in a soldered “pipe” (tube) and the jackscrew and traction screw. The open discussion that followed was sometimes acrimonious. Many well-known dentists in the audience, including John N Farrar and Victor H Jackson, accused Angle of falsely claiming originality. They cited others (including themselves) who earlier introduced similar appliances. Angle carefully explained how his devices were different and better, indeed “new”, but apparently, he did not prevail. The edited paper and subsequent inflammatory discussions were published in the Transactions of the Ninth International Medical Congress under an imposed, truncated, noncontroversial title, “Notes on Orthodontia”. This 1887 article commonly has been called the “First Edition” of his classic textbook on the treatment of malocclusion. Actually, Angle considered that his first edition was his 14-page chapter appended to Loomis P Haskell’s new book on dental laboratory procedures published in 1887; he titled this version of his Congress paper “Extracts of Notes on Orthodontia, with a New System by Regulation and Retention” and it did not contain the discrediting commentaries. Years later, colleagues observed that the bitterness Angle developed from the

contemptuous treatment he received at this 1887 Congress helped harden him for the professional “fights” he was to invite and encounter throughout his adventurous career. To those who would challenge him, his style often seemed abrasive, sometimes brutal; to others, those loyal to him and backing his causes, he was as charming and gentle as a puppy. The year 1892 was a watershed in Angle’s professional development: he announced that he would be practicing orthodontia to the exclusion of all other dental therapies. With this decision, he became the first acknowledged exclusive specialist in orthodontics in the world. Until this moment, none of the authorities on orthodontics worldwide and in history ever mustered the vision and confidence to limit their dental or medical practice to only this emerging type of treatment. Angle was no longer on the faculty at the University of Minnesota. He resigned to concentrate his energies on experimentation in orthodontia and the development of marketable, prefabricated (“ready-made” in his vernacular), new treatment appliances. He also needed time to work on his textbook’s third edition, his first real book, a 51-page work, 20 pages longer than his 1890 edition, which had been published as an appendix in the second edition of Haskell’s prosthetics laboratory book. He hired Anna Hopkins, a bright young Minneapolis secretarial school graduate, to help him with his book and practice. It was the beginning of a life-shaping relationship for both of them. Angle‘S Married Life In March 1887, Edward Hartley Angle married to 22-year-old Florence when he was running 31 years old. Less than 9 months later their daughter Florence Isabel Angle (Fig. 8.3) was born in Minneapolis, only 3 months after her father’s disastrous appearance at the Ninth International Medical Congress in Washington. Angle’s correspondence a dozen years later described a disintegration of this marriage from the start. The couple was grossly mismatched, he the ambitious idea man and she the daydreaming reader of romances. Angle gradually lost respect for Florence “Senior”, as he referred to his wife in some letters, and he became by default an absentee father to their sickly daughter “Florencie”. By July 1900, his personal confidence

Angle’s Contribution to the Faculty of Orthodontics

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Fig. 8.3: Angle’s daughter—Florence Isabel Angle on the left

in his new directions was strong enough to prompt him to move out of their boarding-house apartment in St Louis. He had his thriving practice, his income-producing books, patents and appliances, his growing international fame, his prospering proprietary school, and perhaps most significantly, Anna Hopkins, his secretary, amanuensis, confidante, and sympathetic soul mate (Fig. 8.4). It took Angle another 9 years to deliver an acceptable divorce settlement for Florence senior in May 1908. Angle’s mother had died a few months earlier, and the delay and particular timing of his divorce may well reflect the determination of a devoted son to shield his devout mother from the shame of his broken marriage. On June 28, 1908, Hart and Anna were married in St Louis (at ages 53 and 36, respectively) and within 2 months the newlyweds had moved to New York to begin a new chapter in their lives, as retired gentry. Angle as an Artist It should not be forgotten that Edward Hartley Angle’s personal vision was wide and deep, not simply confined to his profession. He was keen observer of nature in all its forms. The preamble of the citation accompanying the honorary Doctor of Science degree awarded to Dr Angle in 1915 by the University of Pennsylvania acknowledged his broad intellectual base: “Lover of art and nature, intimate friend of trees and flowers, but preeminently founder of the science of orthodontia….” Angle exercised his intellectualism with an active sociability. He was a worldly man who enjoyed people and places; he was an outgoing celebrant and

Fig. 8.4: Edward Hartley Angle

conversationalist. In addition, he was a talented artist, not only with intricate line drawings and creations for clinical orthodontics, but also in crafting gold jewelry, such as stickpins set with semiprecious stones, which he often gave as gifts to friends. Furthermore, Angle was an avid collector of things of the world. He gladly received and studied valuable arts and crafts from friends and his grateful foreign correspondents in South Africa, Japan, and elsewhere. Angle asked his well-known orthodontist-friends and mentors for photographs of themselves and other dental celebrities, both earlier and contemporary, to add to his lantern slide collection, which he projected as a historical prelude to his lectures at various meetings. He loved American-Indian artifacts, arrowheads and tomahawk heads which he challenged his patients and friends to find and trade to him. He collected animal and human skulls and osteological materials in plentiful supply from archeologists excavating the burial mounds around St Louis. He and Anna nourished for over three decades an extensive collection of American-Indian weavings, beadwork, textiles, clothing, and baskets, mostly

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Fig. 8.5: Archeological and ethnographic collections of Angle and his wife Anna Hopkins

from the tribes of the Plains and Great Basin areas of the United States (Fig. 8.5). Most of their archeological and ethnographic collections were donated to institutions and museums in their lifetimes. Almost 300 valuable objects of American–Indian ethnography were given by Anna Hopkins Angle from 1930, the year of Edward Angle’s death, to 1959, two years after her death, to the museum of Claremont College, now the Pomona College Museum of Art in Los Angeles. It represents a living testament to the broad tastes and intellectual vigor of the Angles. About Anna Hopkins (Angle’s Second Wife) About 1908, Angle married his longtime secretary, Anna Hopkins (1872–1957) (Fig. 8.6), who had obtained her DDS degree from the University of Iowa and her orthodontic training in his school. “Mother Angle” became secretary of the American Society of Orthodontists, a founding coeditor of the Angle Orthodontist, and honorary chair of the Angle Society executive committee, but she would be best remembered as Angle’s amanuensis, editor, foil, and buffer for many of his downtrodden students. Some observers have suggested that Anna deserved much of the credit for the high quality of Angle’s written record through her significant literary input during typing. There is absolutely no evidence to support this assertion, given the admirable consistency of Angle’s literary output, handwritten as well as typewritten, even during periods when Anna’s absence was known, such as when she was attending the College of

Fig. 8.6: Anna Hopkins

Dentistry at the University of Iowa from 1900 to 1902. Angle’s letters to Anna are just as colorful and articulate as the rest of his correspondence. However, Anna did provide valuable technical skills and judgment. She knew how to craft solid, well-spelled, grammatically correct text. She likely served as a trusted sounding board for her exuberant boss, and she surely must have woven some subtle corrections and softened phrases into his sometimes acerbic commentaries. Dr Angle often appended his own handwritten corrections, notes, or comments to the final typewritten letters. And to almost all addressees, including some close relatives, he hand-signed his letters boldly as “Edward H Angle.” Only with old friends would he let go and sign a creative or diminutive nickname. At rare times during the 1899 to 1910 period, Anna would sign his letters in his absence. Her version of his signature is rather authentic looking, but still recognizably not his own. For a period in 1901–1902, when Anna Hopkins was away at the University of Iowa studying for her dental degree, Angle’s correspondence was managed by his younger sister, Lillian, an accountant by occupation. The

Angle’s Contribution to the Faculty of Orthodontics

technical quality of the letters that “Lillie” attempted to transcribe during that time was noticeably weaker and Angle knew it. He had to apologize often to his correspondents for lateness and errors, and he resorted to handwritten corrections and appended notes more frequently.

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Angle as a Writer Angle’s style of writing was largely verbal: his letters (and probably his speeches) were dictated to and transcribed by his talented secretary (and later, second wife), Anna Hopkins. He was gifted with the turn of phrase, using colorful language in original ways, and often waxing effusively in a highly readable way. Angle became convinced that anomalies of molar occlusion were prime factors in the origins of most orthodontic problems, including dental crowding. Thus, he took the bold step of popularizing the word “mal-occlusion” in the late 1890s, around the time he was creating his landmark work “Classification of Malocclusion”. Published in 1899, that article brought order out of chaos, simplicity from existing diagnostic complexity, transformations that Angle’s creative mind seemed particularly adept at seeing and doing. Quickly, he changed the title of his textbook from a prosaic “The Angle system of regulation and retention of the teeth …” (1890– 1899) to the then ground-breaking concept, “Treatment of malocclusion of the teeth …” (1900, 6th edition). Angle was a perfectionist whose painstaking exactness in his scientific thinking and writings became a hallmark of his lifetime of work in orthodontics. His detailed letters to managers and book editors of the SS White Dental Manufacturing Company show him as a polymath with a remarkable understanding of the tasks of typesetter, illustrator, and publisher. Angle edited his book six times over, modifying and adding to it every time, as his own expertise developed and progressed, turning what began as a 20-page article in 1887 into a 628-page text in 1907. He always seemed to be at work on an address, an illustrated presentation, or publication. He prepared by hand many of his intricate drawings and by 1900 had a library of over a thousand glass lantern-slides for projection. Besides his well-known textbook editions, Angle wrote around 80 articles for publication in various

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professional journals in the United States, Europe, and Australia between 1887 and his death in 1930. In addition, during his lifetime, close to 100 abstracts and commentaries about his work were published. Another 150 articles are recorded in the indexed scientific literature about Edward Angle and his legacy, and this number continues to grow. In addition to his own writing, Angle’s letters show that he served enthusiastically as a mentor in scientific writing and editing, long before the era of peer review. He generously volunteered ideas and topics for former students and colleagues, including one of his first four students, Milton T Watson, longtime friend William J Brady, and brother-in-law/editor Cy Camp, who was essential in the final editing and proofing of the sixth edition (1900) of Angle’s textbook. Angle conscripted all of them and three other colleagues to write popular articles to increase public awareness of the young specialty of orthodontia in the first decade of the 20th century. Minneapolis merchants Robert Foster and Otto Keidle remained close friends with the Angles from their formative years there. In the Angle letter archive from 1899 to 1910, “Bob and Otto” (also called “White Child and Baron”) received some of the most entertaining yarns and homespun dialects from Edward Angle at his charmingly best. Angle, who no longer used his childhood name “Hart” with newly acquired friends, still often signed off humorously as “Rube” or “Reuben” or the like. In his wellwritten personal ramblings to friends, Angle’s broad and deep nonprofessional interests in people, poetry, literature, history, and the world through clearly. EDWARD HARTLEY ANGLE‘S SCHOOL OF ORTHODONTICS AT PASADENA, CALIFORNIA, USA Angle’s attempts at teaching undergraduate dental students at 4 schools had been frustrated by his inability to separate orthodontics from the dental curriculum, although he finally established the first department of orthodontics in a university (Marion Sims Dental College, Saint Louis, 1897). After the meeting of the National Dental Association in 1899, several members persuaded Angle to train them in his office. This was the first postgraduate course in

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History of Orthodontics

orthodontics, as well as the first school devoted exclusively to the specialty, and it was 3 weeks long. In 1908, he gave up his practice in Saint Louis and moved, first to New York, then to New London, and finally to Pasadena, Calif (1916). Wherever he went, the Angle School went with him. His students erected what was to become the first building exclusively devoted to the teaching of orthodontics (1922). In 1924, the school was chartered as the Angle College of Orthodontia (Fig. 8.7). After heading orthodontic departments at several dental schools, Angle decided he could be more effective by teaching small, select groups in his Saint Louis office. Thus was founded (1900) the first postgraduate school of orthodontics (Angle School of Orthodontia, Fig. 8.8). He also founded the first orthodontic journal, The American Orthodontist, in 1907, but could not prolong its publication beyond 1912. Prior to admission, student was thoroughly grilled in the basic sciences, either by Dr Angle or one of his staff. The applicant was expected to know the anatomy, embryology and histology of the head and neck (exclusive of the brain), the

Fig. 8.7: Angle school of orthodontia

Fig. 8.8: Angle School of Orthodontia, first postgraduate school for orthodontists

growth, development, and functioning of the denture. He also expected the applicant to be reasonably familiar with history, general science, and English literature. Filing, soldering, and wire bending had to be mastered before the student was permitted to do any appliance manipulation. Only after surviving the rigors of discipline, theory, technique, and case analysis, the student was allowed admission to the clinic. In June 1922, the members of this school founded a formal association: The Edward H Angle Society of Orthodontia (commonly called the Angle Society). The meeting of this society in New London in 1928 was the last meeting that Angle ever attended. They had no acrylics, no alginates, no light wires, no model trimmers and no preformed bands. Impressions were taken in plaster and, because undercuts prevented removing the stony mass in one piece, the operator was obliged to score the material and pry it off, piece by piece. he poured impression was later trimmed by hand with a plane, a saw, or a huge file. APPLIANCE CONTRIBUTION BY EDWARD H ANGLE Edward H Angle’s correspondence and patents reveal features of the most dynamic side perhaps of this multidimensional man: the rapt and consummate inventor, a human wellspring of new ideas (Fig. 8.9). During his lifetime, Angle applied for and received 45 patents (his wife Anna obtained his 46th patent in 1934, four years after his death). Most were appliances and instruments related to clinical orthodontics, but they included laboratory equipment and a novel automobile wheel. His contemporary role models were likely among the new breed of inventive, risk-taking industrialists, such as Thomas Edison, George Eastman, and Charles Kettering. America led the world by the beginning of the 20th century in technological innovation and entrepreneurship. In the first years of the 1900s, American medicine was ablaze with new light and directions for the medical and dental community. At Johns Hopkins University, William Osler initiated creative reforms in clinical education and singlehandedly systematized the field of internal medicine. At Northwestern University, Greene Vardiman Black introduced the nomenclature of

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Angle’s Contribution to the Faculty of Orthodontics

Fig. 8.9: Edward Hartley Angle

tooth anatomy and the modern principles and tools of operative dentistry. Edward Angle’s rationale for patenting his inventions was to take legal claim of his ideas and to protect his business interests. However, many of Angle’s colleagues criticized him for the zeal with which he protected his breakthrough appliances and systems for doing “tooth regulation” and “orthodontia” more easily. Patent protection certainly makes sense in today’s high-stakes environment of corporate espionage and intellectual property rights, but in Angle’s time, patenting—particularly in medicine—was viewed in many circles as selfish and mercenary. Angle’s enthusiasm for advancing the materia technica of orthodontics was so strong that he freely mentored, encouraged, and worked with colleagues in their efforts to develop new appliances. This is seen in Angle’s letters to Henry A Baker of Boston in which he praises the “Baker method of anchorage” and later seeks to protect Baker’s professional reputation as the first to use inter-maxillary anchorage against equal claims made by Calvin S Case of Chicago. It is also apparent in his letters to E L Townsend where he encourages Townsend to write and publish articles concerning Townsend’s idea for a prosthetic bridge appliance. Angle worked cooperatively with several of his former students

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to develop orthodontic appliances and instruments: Jacob Lowe Young, Spencer R Atkinson and Albert H Ketcham each jointly held patent rights to one or more inventions with Angle. Furthermore, trusting the biomechanical acumen of his former student Milton T Watson, Angle asked him to try out competitors’ orthodontic appliances and to conduct a comparative study and report back to Angle with his conclusions. Angle, the enterprising innovator, worked and reworked designs to develop the best appliances. As President of the E H Angle Regulating Appliance Company, incorporated in St Louis in May 1907, he kept track of the work of other inventors active in the budding field of orthodontia and maintained a folder with relevant patents filed by others. Within the 11year record of correspondence covered by the Angle letter archives, he relentlessly hounded those he perceived as idea stealers, patent infringers, and plagiarists—Clarence D Lukens, James N MacDowell, and Miland Knapp, and manufacturers Julius Aderer, Claudius Ash, and Blue Island Specialty Company. In anger, he slapped some with lawsuits and inflammatory defamations. The age-old rule that brilliant inventors make poor business people did not apply to Edward H Angle. He was in fact the consummate, confident businessman, maximizing income and minimizing expenses. Angle was a demanding taskmaster in his detailed letters to the machinists to whom he outsourced appliance manufacture at various times: William Hahn, the Hardinge brothers, and John E Canning. They were required to fabricate his devices with tight tolerances and on tight budgets. He held the SS White Dental Manufacturing Company, which by 1895 became the exclusive distributor of the Angle System, to a rigorous Angle-controlled business relationship. His detailed handwritten invoices from the “E H Angle Regulating Appliance Co” show his (and Anna’s) arithmetic accuracy in billing to the penny, making a lie of his schoolboy reputation of being weak with numbers. Angle’s Patented Orthodontic Devices, first patent in 1889 is push type jackscrew which was used to increase the width of the arches there by treating the malocclusions. In 1851, a lingual arch soldered to bands that are cemented on teeth;

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History of Orthodontics

forcing teeth “outward and forward”. Special pliers pinched the wire increasing its length. In 1899 Edward H Angle developed the “E” (expansion) arch appliance where in the arch wire with threaded ends, extended in the tube of an anchor molar band. Nut is provided with a thread less extension that works with a friction sleeve to hold the adjustment. According to the nut’s position, the teeth could be moved either distally or mesially. The banded teeth were attached to the arch with the help of a soft wire that allowed their tipping or aligning.

A

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E-arch Appliance E-arch appliance was developed by Angle in early 1900. It is also referred to as Edward Angle‘s Earch. It was the first Angle’s Orthodontic appliance developed to treat malocclusions .Earch appliance consists of bands which are placed on molar teeth on either side of the arch of a heavy labial arch wire extended around the arch. The ends of labial extended arch wire threaded to the buccal aspect of the molar bands allowed the arch wire to be advanced so that the arch perimeter increased. Individual teeth were ligated with the heavy labial extended arch wire with ligature wire of 0.010" (Figs 8.10A to D).

B

Pin and Tube Appliance Pin and tube appliance was also developed by Edward H Angle. In this pin and tube appliance, all teeth are banded. Vertical tubes were welded to the bands on the labial surface in the center of the crown for all teeth in the arch. Arch wires were secured with soldered pins that inserted into the vertical tubes (Figs 8.11A to C).Tooth movement was achieved by altering the placement of these pins. Pin and tube appliance is also used for treating malocclusions.

C

Ribbon Arch Appliance Ribbon arch appliance was also developed by Edward H Angle and it is the modification of pin and tube appliance. This appliance was introduced in 1910. Ribbon arch was the 1st appliance to use a true bracket .The bracket has a vertical slot facing occlusally.The brackets were attached to the bands at the center of labial surface of teeth (Figs 8.12A to C).

D Figs 8.10A to D: E-arch appliances

Angle’s Contribution to the Faculty of Orthodontics

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A

A

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B

B

C Figs 8.11A to C: Pin and tube appliance

Edgewise Appliance In order to overcome the deficiencies encountered with his previous techniques Angle desired a metal bracket that could give a better control over individual tooth movement. The edgewise bracket has a rectangular slot facing labially, rather than occlusally or gingivally, which receives a rectangular arch wire. This unique feature of rectangular arch wire in a rectangular slot enabled control of tooth movement in all three planes of space. Furthermore, the bracket has four wings, two occlusal and two gingival, which increase the surface of arch wire with the bracket slot and thus give accurate control over tooth movement (Figs 8.13A to C). The term Edgewise refers to the method by which rectangular arch wire is inserted into the horizontal slotted bracket. The edgewise appliance was developed and introduced to orthodontic by Edward H Angle in the year 1925. ANGLE’S ORTHODONTIC MATERIAL INVENTION The highly popular Broussard bracket of the 60s and 70s was based on this patent. Concern about

C Figs 8.12A to C: Ribbon arch appliance

the biological response to foreign bodies used in oral environment. Reflected in many of his patents in which he has constantly tried to cover all possibilities for adverse use or unfavorable reaction. Angle made an inventory of the available materials—gold, silver, platinum, platinous silver, iridio-platinum, platinoid, aluminum, brass, copper, aluminum bronze, steel, iron and vulcanized rubber. He found that “the material most fitting was nickel silver”, a

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History of Orthodontics

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A

B

Fig. 8.14: Calvin Case

C Figs 8.13A to C: Edgewise appliance

brass (copper-zinc alloy) that did not have any silver in it at all! He was largely self-taught, and yet he mastered complex metallurgy. In one of his publications, he explains that pinching the arch. “Not only spreads the particles of metal, so as to increase the length of the rod, but tempers the part subjected to the pinching action, thereby largely compensating for the reduction in the area of the rod section at that point, and consequently maintaining the strength and rigidity of the rod under the longitudinal strain thereon.”His knowledge of noble metals is witnessed also by his use of gold and of platinum-iridium arches in orthodontics. He was the first to use coil springs. But he connected them only to nobler metal

arches. In 1887 introduction in orthodontics of soldering and a “baser” alloy which contained, 60% to 70% copper, 10% to 20% zinc and10% to 15% nickel. Angle was influenced by Julius Wolff. “Wolff’s law of bone”—bone trabeculae arranged in response to stress lines on the bone. Angle had an uncompromising position against extraction. It was his credit that “The best balance, the best harmony, the best proportions of the mouth in its relation to the other features require that there shall be a full complement of teeth, and that each tooth shall be made to occupy its normal position, i.e. normal occlusion.” CASE-ANGLE CONTROVERSY Originally, Calvin Case (Fig. 8.14) was a genuine admirer of Angle. He advocated the Angle system at every turn and hoped to place this system before the dental profession. In fact, he gave up the general practice of dentistry because of Angle’s influence. The discord started over the claim that Angle attributed the origin of the use of inter-maxillary elastics to Baker, while Case thought that he should have received that credit. In fact, when Angle described this procedure, he never mentioned Case. This led to charges and

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Angle’s Contribution to the Faculty of Orthodontics

countercharges between them in 1903. Case’s claim was that in 1890 he started this procedure and reported it at the Chicago Dental Society and also at the Columbian Dental Congress in 1893. The second point of contention was and is the one usually remembered the question of the extraction of certain teeth as a means of treatment. Angle’s thesis was that “there shall be a full complement of teeth, and that each tooth shall be made to occupy its normal position.” Case defended the discreet use of extraction as a practical procedure, while Angle believed in non-extraction. However, the unexpected result of this controversy was that it convinced general practitioners that they should not attempt orthodontic treatment but should refer patients to the specialist. The extraction story was continued into 1911 with Martin Dewey (1881–1933) (Fig. 8.15) an ardent champion of non-extraction. Dewey served as professor of Orthodontics at Kansas City Dental School, the University of Iowa Dental Department, the Chicago Dental College, and the New York College of dentistry. He gained a wide reputation as an outstanding teacher. He had started his own graduate school in orthodontics in 1911 as the Kansas City School of Orthodontia and continued it as he traveled from one city to another, ending

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in New York City with his death in 1933. His influence was much felt since he was the editor of the International Journal of Orthodontia for 17 years and also the president of the American Dental Association in 1931. CRITICISMS Bernstein Dr Angle did great harm to many persons, and to orthodontics, at the same time he was making his many contributions. Theodore Adler By all accounts Angle was a difficult man. He is reputed to have harbored much of the bigotry and some of the xenophobia of his time. Wuerpel • “He did not like the Germans. He was broadminded but he had prejudices.” • “He lost many friends, or at least he alienated them”. • “If people had heard the terms he used in regard to them he would have had still more enemies”. Frederick Noyes • Angle “could never take criticism or argument”. • When his ideas were verbally attacked, he would call his attackers “fools”. Tom Graber • Edward.Hartley.Angle. was obviously a disturbed man, and his image has been built up, far beyond what he deserved” • “Approach became a classic example of cultism and dogma.” • “Case was more successful as a contemporary leader than Angle. Case was on the inside leading while Angle was the maverick. He resented Calvin Case.” Lischer

Fig. 8.15: Martin Dewey

“So I turned to the first special course then being offered. Unfortunately, being a resident of St. Louis, where the course was then given, I was

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History of Orthodontics

asked to sign a contract to locate elsewhere on completion of the instruction. Angle added: ‘You know, Lischer, I can pick the flowers in my garden myself.‘ Robert Rubin Angle possessed many of the personality qualities seen in geniuses. They can be difficult, demanding, and unforgiving. They tend to be so devoted to their field that they fail to develop other aspects of their lives. Angle seems to fit that category.”

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Wuerpel It (orthodontics) was his religion and his god. He would sacrifice everything for its sake. He could only see his life and his work and his devotion in terms of orthodontia.” Edward H Angle’s Publications and Presentations Though Angle died 1930, his influence is still felt strongly in orthodontics. Even his enemies recognized the many contributions made by Edward Hartley Angle. His pioneer efforts in orthodontic education, his contribution to orthodontic literature, and his developments of innumerable instruments and appliances are not the accomplishments for which he will be remembered. Long after these have faded into history, Angle’s name will be associated with the onward march of biologic science and it will be realized how perceptive was the mind that could penetrate the empiricism of his day and proclaim the significance of normal occlusion. This established orthodontia as a science and it will remain Angle’s greatest monument. Characteristic of the man was a remark made shortly before he died: “I have finished my work. It is as perfect as I can make it.” Date

Event

June 1, 1855

Eward Hartley Angle born to Philip Casebeer Angle (1820– 1907) and Isabel Erskine Angle (1824–1908) in district 1 “Ballibay”, Herrick Township, Bardford County, Pennsylvania. The fifth of seven children. Demonstrates early talent for using tools and devising and

constructing machinery, including a hay rake (at age 11); attends high school in Canton, Pennsylvania. 1874–1876 Apprentices with a local dentist in Herrick. Fall 1876– Attends the Pennsylvania February 1878 College of Dental Surgery in Philadelphia, receiving DDS degree on February 28, 1878; beings practicing dentistry in Towanda, the county seat of Bradford County, Pennsylvania. Here he develops an interest in orthodontia. Spring 1881 Develops a chronic respiratory ailment, called pleural pneumonia, probably tuberculosis. Autumn 1881 Moves to Minneapolis, Minnesota, for health reasons. Within months, his health recovers and he returns to Pennsylvania briefly to join his older brother Mahlon and friends in planning a sheep-raising venture in Montana. Late 1881 Moves to Montana with associates to enter the sheep-ranching business. Early 1882 The severe winter of 1882 kills their sheep flock and dooms the venture financially. 1882–1883 Relocates to Minneapolis and resumes the private practice of dentistry; continues his interest in orthodontia. 1886 Accepts position as professor of histology and lecturer on comparative anatomy and orthodontia in the Dental Department of the Minnesota Hospital College in Minneapolis. Two year later, it becomes part of the University of Minnesota, and he is elevated to professor of orthodontia. Maintains his part-time private practice of dentistry. March 1887 Marries florence A Canning of Minneapolis, sister of his machinist Hohn E Canning. September 8, Present of his first major address

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1887

describing aspects of the Angle System of Regulating Appliances before the 9th International Medical Congress in Washington, DC. Angle’s originality is challenged in the heated discussion that ensues. Angle later considers a 14 page extract of this paper, published without discussion in an 1887 textbook by Loomis P Haskell, as the “first edition” of the Seren American editions of his famous book. December 3, Daughter Florence Isabel Angle 1887 is born in Minneapolis. (She died in 1970 in Morganton, North Carolina.) 1888 Elected president of the Minneapolis City Dental Society. March 5, 1889 Patents a jack-screw machinism, the first of 46 patents held by angle. 1890 “Second edition” of his book is published, as a 30-page appendix to the second edition of a dental laboratory handbook by Loomis P Haskell. 1892 Resigns from the faculty at the University of Minnesota; limits his practice exclusively to orthodontia, thus becoing ostensibly the world’s first specialist in orthodontia. 1892 Hires Anna Hopkins (1872– 1957) of Minneapolis as his secretary and office assistant. 1892 Publishes third edition, a 51page pamphlet entitled, The Angle System of Regulation and Retention of the Teeth. 1892–1898 Professor of orthodontia at the American College of Dental Surgery (later merging into Northwestern University School of Dentistry) in Chicago. 1894 Appointed surgeon to the Great Northern Railroad for the treatment of fractures of the maxillae.

1895

1895

1896–1899

1897–1898 1897

1897 1899

1899

June 6, 1899 August 1899

73 Fourth american edition is published, a 112-page hard-cover book now titled. The Angle System of Regulation and Retention of the Teeth and Treatment of Fractures of the Maxillae. Relocates to St Louis, Missouri (with his wife Florence, his daughter florence Isabel, and his secretary-assistant Anna Hopkins; sets up a private practice there limited to orthodontia. Professor of orthodontia in the Dental Department of MarionSims College of Medicine, St Louis. Teaches in the Dental Department of Washington University, St Louis. Fifth American edition is published by SS White, philadelphia; also a German translation of his fourth (1895) American edition is published by SS White Co, Berlin. Is awarded MD degree from Marion-Sims College of Medicine. Dental Cosmos publishes Angle’s “Classification of Malocclusion”, his most important journal article to date. Claudius Ash publishes Gustave Darin’s French translation of Angle’s book under the title Methode du Professeur Angle Pour la Regularisation et le Traitement des Dents et Pour le Traitement des Fractures des Maxillaires. Patents the E-Arch, his expansion archwire mechanism. Angle’s paper on orthodontia prepared for presentation at the National Dental Association meeting at Niagara Falls is bypassed at the last minute by program officials. This personal slight fuels Angle’s desire to found a postgraduate school of

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History of Orthodontics

orthodontia and a professional society devoted to orthodontia. November 1899Teaches a postgraduate course on orthodontia in his office in the Olivia Building, St Louis. Attending are thomas B mercer, Henry E Lindas, Herbert A Pullen, and Milton T Watson. December 8, Resigns his appointment of 1899 Marion Sims college of medicine. 1900 Founds the Angle School of Orthodontia; first 5-week course is held from May 1 through early june 1900 in the odeon Building, St Louis. July 1900 Separates from wife Florence Canning Angle. October 1900 Publishes sixth edition, a 315page work, Treatment of Malocclusion of the Teeth and Fractures of the Maxillae. Angle’s System. Early 1901 Founds the Society of Orthodontists (antecedent of the American Association of Orthodontists) and serves as its first president. Early 1901 Founds the Society of Dental Science of St Louis. July 1901 First meeting of the Society of Orthodontists (renamed in 1902, The American Society of Orthodontists) is held in St Louis, Missouri. 1902 With Angle’s encouragement, Anna Hopkins graduates from the University of lowa with a DDS degree. December Offered the editorship of orth 1902 odontia of the international Dental Journal; Angle declines the offer. August 29– Chairman of Section VI September 3, (Orthodontia) of the fourth 1904 International Dental Congress, St Louis. 1904 German translation of his fifth (1895) American edition is published by SS white Co Berlin.

1905

Contributes chapter on orthodontia in Edward C Kirk’s American Textbook of Operative Dentistry (also in 1911 edition, revised). Spring 1906 Resigns membership in American Society of Orthodontists; encourages establishment of The Alumni Society of the Angle School of Orthodontia (Earliest Forer-unner of the Edward H Angle Society of orthodontists). Winter 1906– Retires from practice of 1907 orthodontia in St Louis; focuses on writing seventh American edition of Treatment of Malocclusion of the Teeth, Angle’s System (628 pages). 1907 Father Philips Casesbeer Angle dies, age 87. May 1907 Incorporates the EH Angle Regulating Appliance co in St Louis, Missouri. June 1907 Founds The American Orthodontist, the first journal in the world devoted exclusively to orthodontics (discontinued in 1912); it is the forerunner of The Angle Orthodontist. 1908 Mother Isable Erskine Angle dies, age 84. May 1908 Divorces Florence Canning Angle in Minneapolis, Minnesota. June 27, 1908 Marries Anna Hopkins in St Louis, Missouri. Summer 1908 Moves from St Louis with wife Anna H Angle to Larchmont, New York. September 15– The Angle School of orthodontia October 31, is in New York City for a 6-week 1908 course, in an office building at rhe corner of West 72nd Street and Broadway. Fall 1908 Hemann Muesser publishes Josef Grunberg’s German translation of Angle’s sixth (1900) American edition under the title Behandlung der Okklusionsanomalien der Zahne.

Angle’s Contribution to the Faculty of Orthodontics

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April 1909

Purchases home at 58 Bellevue Place, New London, Connecticut. July 1909 Wins patent infringement suit against appliance manufacturer Julius Aderer. October – The Angle School of Orthodontia December 1909 moves to New London, connecticut; course session lengthened to 9 weeks, given in the Munsey Building. July– Second (final) course session in September New London at the Harbor 1911 School, after which Angle closes Angle School of Orthodontia due to his declining health. 1913 Revised and expanded German edition of Angle’s book (1907 American edition) is published with new chapters by Josef Grunberg and Albin Oppenheim (778 pages). February 22, Awarded Honorary ScD degree 1915 by the University of Pennsylvania. Late 1916 Angle moves to southern Califomia for health reason; purchases home at 1025 North Madison Avenue, Pasadena. 1917 At request of Hames C Angle (no relation), he reopens the Angle School of Orthodontia at his home in Pasadena. 1922 Edward H Angle Society of orthodontists is started in Califor-

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nia by graduates of the Angle School of Orthodontia. 1922–1923 Grateful students fund construction of a building in Pasadena for the Angle School of Orthodontia at 550 Jackson Street, next to Angle’s home; it is dedicated on January 8, 1923. 1924 The Angle College of Orthodontia and Infirmary is chartered by California. No tuition is charged for the college’s 12-month program (which is followed with periodic faculty supervision during the first year of private practice). All patients were treated free of charge. September 15, Patents the edgewise arch 1925 mechanism. Late 1927 The Angle College of Orthodontia closes unofficially due to Angle’s deteriorating health. August 11, Edward H Angle dies in Santa 1930 Monica, California, at age 75 from heart failure; burial at Mountain View Cemetery, Altadena, California. November 17, The Angle Orthodontist, a 1930 scientific journal devoted exclusively to orthodontics, is founded in chicago in Dr Angle’s memory by the newly reorganized Edward H Angle Society of Orthodontia.

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History of Orthodontics

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• Thomas M Graber (1917–2007) • TM Graber’s Contributions

THOMAS M GRABER (1917–2007) Dr TM Graber as an Orthodontist, Researcher, and Dental Educator Dr Thomas M. “Tom” Graber, known internationally as an orthodontist, researcher, and dental educator, born in St Louis on May 27, 1917 and died on June 26 at age 90, in Evanston, Illinois. Dr Thomas M Graber was certainly a pioneer amongst men. His complete devotion and love for the specialty of orthodontics is reflected in his extensive works on a myriad of topics, spanning over a period of nearly six decades. As Dr Graber’s family friend and colleague Dr Jim McNamara noted, “Tom’s energy and enthusiasm for our profession make him a wonderful role model for future generations of orthodontists.” The passing of Dr Thomas M Graber marks the end of an era in orthodontics. Dr TM Graber’s Dental Graduation Dr Graber earned a DMD degree in dentistry (Washington University, 1940), an MSD in orthodontics (Northwestern University, 1946), and a PhD in anatomy (Northwestern University, 1950). Dr TM Graber’s Working Experience Dr TM Graber served as a captain in the United States Army Dental Corps from 1941–1945. He was on the faculty of Northwestern University from 1946–1958 at the University of Chicago from

9

• Graber’s Other Contributions to Orthodontics

1969–1982, where he was the head of the Section of Orthodontics; and at the University of Illinois at Chicago College of Dentistry from 1994 until his death. He also served as a visiting professor on the faculties of the University of Michigan. The University of Freiburg, Germany, and the University of Gothenburg, Sweden. A natural teacher, he was “one of those people who could take complex subjects and explain them clearly to students,” said his wife, Doris, a professor of political science at the University of Illinois at Chicago. A pioneer in orthodontics and craniofacial biology, Dr Graber did research on craniofacial anomalies, cleft palate, cleft lip, temporomandibular joint anatomy and disturbances, orthopedic growth guidance of the dentofacial complex, and the use of magnetic forces in orthodontics and dentofacial orthopedics. His 60 years of research have added to our knowledge in these fields and changed the way they are taught around the world. He gave more than 475 continuing education courses around the world and was on the American Association of Orthodontists Annual Session program more than any other person in AAO history. Beginning in 1951, he made annual lecture tours to university departments and medical and dental societies around the world. He wrote 28 books on orthodontics and dental anatomy and contributed chapters to 20 other books. He wrote more than 175 scientific articles in refereed dental and medical journals, not to

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Dr TM Graber’s Contribution to Orthodontics

mention hundreds of book and journal article reviews and abstracts. From 1985 to 2000, he served as editor-in-chief of the American Journal of Orthodontics and Dentofacial Orthopedics. He went on to found the World Journal of Orthodontics, and he continued as editor-in-chief of that publication until his death. Dr Graber’s contributions to organized orthodontics and orthodontic education were unsurpassed. He served on the AAO Council on Orthodontic Education from 1962 to 1973; founded the Audiovisual Council of the AAO in 1962; was general chairman of the AAO Annual Session twice; founded the Kenilworth Dental Research Foundation; was director of Continuing Education for the G. V. Black Institute since 1967; was director of Dental Continuing Education for the University of Chicago Center for Continuing Education from 1971 to 1981; founded the Northwestern University Cleft Lip and Palate Institute and the Orthodontic Section at the University of Chicago Medical School; was a founding member of the Illinois Society of Orthodontists; and was a former president of the Chicago Society of Orthodontists, the Midwest Component of the Edward H. Angle Society, and the Illinois Society of Orthodontists. Dr Graber held appointments at Children’s Memorial Hospital and Wyler Children’s Hospital in Chicago. He received honorary doctoral degrees from the University of Gothenburg, Sweden, 1989; Washington University, St Louis, 1991; the University of Michigan, 1994; Kunming Medical University, China, 1996; and Aristotle University of Thessaloniki, Greece, 2005. His honorarydegrees from Washington University and the University of Michigan were the first and only ones ever given to a dentist. Dr Graber received awards too numerous to list. He was quite proud to be the first non-Japanese person to be inducted as a member of the Japan Orthodontic Society in 1997, and he received the Emperor of Japan’s Order of the Sacred Treasure, the highest Japanese award ever bestowed upon a noncitizen of Japan, in 2003. Active in his community, Dr Graber was a member of the Sons of the American Revolution, Fort Dearborn Chapter; and had been a leader in the Boy Scouts of America where all four sons became Eagle Scouts. He was a generous philanthropist, having endowed a professorship at the University of

77

Michigan and contributed to the University of Illinois at Chicago College of Dentistry as well. Dr Graber enjoyed travel, visiting countries around the world and even the North Pole and Antarctica. He enjoyed photography; he skied, played tennis, bicycled, swam, went scuba diving, and sailed—pursuing many of these activities well into his 80s. He is survived by his wife of 66 years, Dr Doris Graber; sons Dr Lee W Graber, Dr Thomas W Graber, Jack D Graber, and Dr Jim M Graber; daughter Dr Susan Graber; and 14 grandchildren. TM GRABER’S CONTRIBUTIONS TM Graber’s contribution are listed and explained below; Physiology of Occlusion Normal Occlusion — TM Graber (DCNA, 1968) In this paper, Dr Graber states that any definition of normal occlusion cannot be static and merely descriptive of tooth relationships. Normal occlusion involves not only the teeth, but also the investing tissues, the contiguous and motivating musculature, curve of Spee, inter-occlusal clearance, and the TMJ morphology and function. He has organized the historical progress in the development of current concepts of occlusion into three periods: • Fictional period (before 1900) • Hypothetical period (1900–1930) • Factual period (1930 – present). Fictional Period • Concepts were developed from inductive analysis. • Terminology was loose and reflected the personal preferences of the authors. • Authors talked about dental antagonisms, “meeting” or “gliding” of teeth. • Good descriptions of the morphologic nature of individual teeth existed, but an appreciation of the functioning dentition as a whole was lacking. Hypothetical Period It was EH Angle who organized the existing concepts of occlusion at the time and formulated definite principles of diagnosis in treatment.

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History of Orthodontics

• He gave the ‘key of occlusion’ based on the position of the upper first molar. • Angle described normal occlusion using a skull that he called ‘Old Glory’. • Calvin Case developed the concept of “apical base”. He also called attention to the effect of the nose and chin button on the profile. • In 1908, Bennett suggested the functional analysis or the dynamic approach to occlusion for the first time. He noted that the mandible had a resting position (depended on musculature) and a functional position (depended on the teeth in maximum contact).

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Factual Period • With the introduction of biometric procedures and scientific methodology, this period saw a trend toward the dynamic and a de-emphasis on the static. • In 1931, B. Holly Broadbent introduced radiographic cephalometry. • Occlusion now meant inter-digitation of teeth plus the influence of the musculature as well as that of the temperomandibular joint. The Developing Occlusion—Orthodontic Considerations for the Handicapped — Owen, Graber (DCNA, 1974). • The authors state that the nature and severity of the handicap in a child may totally dominate the dental diagnostic and treatment considerations. • They have described the type of care to be rendered according to the severity of the handicap – mild, moderate, severe. • Timing, case selection and management are the main factors in treating or not treating the handicapped patient. • It is important to weigh the possible benefits to the child with the individual’s physical and dental status as affected by his ability to comprehend and cope with orthodontic procedures. The “Three M’s”: Muscles, Malformation and Malocclusion — TM Graber (AJO, 1963) • In this classic article, Dr Graber has analyzed muscles and their relationship to structural

• •

•

•

•

configuration in Class I, Class II, and Class III malocclusions. “Whenever there is a struggle between muscle and bone, bone yields.” Muscle function can be adaptive to morphogenetic pattern. A change in muscle function can initiate morphologic variation in the normal configuration of the teeth and supporting bone, or it can enhance an already existing malocclusion. In the latter instance, the inherent structural mal-relationship calls for compensatory or adaptive muscle activity to perform the daily functions. The structural abnormality is increased by compensatory muscle activity to the extent that a balance is reached between pattern, environment, and physiology. It is imperative that the orthodontist appraise muscle activity and that he conduct his orthodontic therapy in such a manner that the finished result reflects a balance between the structural changes obtained and the functional forces acting on the teeth and investing tissues at that time.

The Role of Upper Second Molar Extraction in Orthodontic Treatment — TM Graber (AJO, 1955) • In Class II treatment, the greatest change produced by the orthodontic appliances is in the maxilla. Distal adjustment of tooth position in the maxilla alone, or in conjunction with mandibular growth, is the basis for correction. • If space required for the tooth adjustment is gained in the second molar area, only as much space as required need be used, with the subsequent mesio-vertical eruption of the maxillary third molars filling the gap. • Maxillary 2nd molar removal expedites correction of Class II division 1 malocclusion, provided that: • There is excessive labial inclination of the maxillary incisors, with no spacing. • Overbite is minimal. • 3rd molars are present in the maxilla, in good position and of proper shape. • The cases offering the poorest prognosis for maxillary 2nd molar extraction are severe basal dysplasias with vertically inclined

Dr TM Graber’s Contribution to Orthodontics

maxillary incisors, no spacing, and severe overbite.

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Maxillary Second Molar Extraction in Class II Malocclusion — TM Graber (AJO, 1969) • In this paper, Dr Graber has again dwelled upon the removal of upper 2nd molars as a therapeutic means for correction of Class II malocclusion. • He recommends the extraction of maxillary 2nd molars in those instances in which there are good maxillary 3rd molars and where there is a significant Class II/1 malocclusion and involvement of all 4 tissue systems – teeth, bone, muscle and nerve. • A fixed lingual arch is used to prevent the mandibular 2nd molars from over-erupting. • The results appear to be stable over a long period of time. • The iatrogenic reaction is minimal or nonexistent. Extraoral Force—Facts and Fallacies — TM Graber (AJO, 1955) • Dr Graber studied 150 cases of Class II/1 malocclusion treated with extra-oral force using the same type of appliance. • The appliance consisted of molar bands, a .045 inch stainless steel labial arch wire with vertical spring loops at the lateral-canine embrasure to receive the cervical gear. This was a metal tube with a continuous spring inside to provide distal motivating force. He concluded that: • Class II/1 malocclusions are amenable to correction by the use of extraoral force. Marked improvement in the basal relations can be obtained; overbite and overjet problems can be helped greatly. • Coordination of treatment with the pubertal growth spurt ensures a greater likelihood of success [10–12 years in girls; 12–17 years in boys]. • Certain untoward sequale may be seen in the use of extraoral force. These include: • Incomplete correction of tooth malrelationship, • Excessive distal tipping of maxillary 1st molars, • Possible impaction of maxillary 2nd or 3rd molars, • Possible excessive lingual tipping of maxillary incisors,

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• Possible unilateral response in correction of class II relationship, and • Difficulty in the control of excessive overbite. Dentofacial Orthopedics versus Orthodontics — Graber, Chung, Aoba (JADA, 1967) • In this paper, the authors have reported that orthopedic therapeutic measures with heavy and interrupted force against the bone may be used successfully in orthodontics. • Greater use of this type of extraoral force is recommended because of its superior ability to correct basal jaw anteroposterior malrelationships. • In addition, there is greater stability, a lower percentage of tooth extractions, minimal use of intra-oral appliances, less attendant orthogenic damage (decalcification, root resorption), minimal chair time, and longer intervals between appointments. • An occipital base of anchorage is more satisfactory for correction of Class III mandibular prognathism. • In cases of open bite, the direction of restrictive force must be as vertical as the design of the cranial cap will permit. • In Class II/1 malocclusion, a cervical source of anchorage is satisfactory. Heavy Intermittent Cervical Traction in Class II Treatment: A Longitudinal Cephalometric Assessment — Mills, Holman, Graber (AJO, 1978) Investigated the changes brought about in the dentofacial complex as a result of the use of heavy cervical traction forces applied intermittently in the maxilla in growing Class II division 1 patients, and compared with untreated controls. Their findings showed that there was: • A stable reduction in the ANB angle is seen. • SNA did not move downward during treatment; no significant tipping of PP occurred. • Less forward progress of point B and Pog occurred in treated group. Thus, SNB was constant. • Mandible was rotated downward and backward—slight increase in SN-MP angle. • Significant decrease in overbite occurred during treatment.

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History of Orthodontics

• U1-SN decreased during treatment, but increased during follow-up. • Treatment had marked withholding effect on normal downward and forward eruption of maxillary 1st molars. However, in posttreatment period, these teeth erupted more than in controls, losing some of the treatment effect. • Distal tipping of upper molars occurred during treatment, but relapsed after appliance removal. • Distal uprighting of lower molars and incisors occurred during treatment. Molar position was stable, but incisors relapsed following treatment. • Sagittal arch length decreased significantly during treatment. This effect was stable. • Both the downs OP and functional OP tipped downward anteriorly as a result of treatment, and relapsed insignificantly following treatment. • Anterior facial height increased more than normally as a result of treatment. Most of this change took place in the lower facial height. The Effectiveness of Protraction Face Mask Therapy: A Meta-analysis — Kim, Viana, Graber, Omerza and BeGole (AJODO, 1999) This study examined the effectiveness of maxillary protraction with orthopedic appliances in Class III patients. A meta-analysis of relevant literature was performed to determine whether a consensus exists regarding controversial issues such as the timing of treatment and the use of adjunctive intra-oral appliances. The results showed that there was: • No distinct difference between the palatal expansion group and non-expansion group except for 1 variable, upper incisor angulations, which increased to a greater degree in the non-expansion group. This finding implies that more skeletal effect and less dental change are produced in the expansion appliance group. • Examination of the effects of age revealed greater treatment changes in the younger group. • Results indicate that protraction face mask therapy is effective in patients who are growing, but to a lesser degree in patients who

are older than 10 years of age, and that protraction in combination with an initial period of expansion may provide more significant skeletal effects. Craniofacial Features of Patients with Class III Abnormalities: Growth-related Changes and Effects of Short-term and Long-term Chin-cup Therapy — Deguchi, Kuroda, Minoshima and Graber (AJODO, 2002) • The craniofacial features of patients with Class III abnormalities, including growthrelated changes and effects of short-term and long-term chin-cup therapy, were studied. • Twenty female subjects were treated with chincups and an orthopedic force of 500 g for 31 months (short-term treatment group). Another 36 female patients were treated with chin-cups and a force of 250 to 300 g for 86 months (longterm treatment group). • Cross-sectional lateral films of 562 skeletal Class III girls served as controls. Their results showed that: • Short-term treatment resulted in a slight improvement in ANB angle and Wits appraisal, while long-term treatment resulted in a significant improvement in ANB angle and Wits appraisal. • Such treatment also resulted in a significant inhibition of the growth of the ramus (2.2 mm) and body length (3.6 mm) of the mandible, a backward rotation of the mandible, and a reduction (8.2°) of the gonial angle. • However, there was no alteration of any parameter of the maxilla and the cranial base, except the length of S-N and N-S-Ar in the longterm treatment group. Long-term Application of Chin-cup Force Alters the Morphology of the Dolichofacial Class III Mandible — Deguchi, Kuroda, Hunt and Graber (AJODO, 1999) • Investigated the immediate and long-term effects of prolonged use (mean, 7 years 2 months) of chin-cup appliances in subjects with dolichofacial Class III mandibles. • Thirty six female subjects with severe skeletal Class III malocclusions, associated with large gonial angles, were studied.

Dr TM Graber’s Contribution to Orthodontics

• At post-treatment (T1, 65 months duration) and post-retention (T2, 56 months after T1), Ar-Me and Wits appraisal cephalometric parameters were significantly different between patients and control subjects (n = 230). • The Go-Me parameter in treated subjects was longer than that of the controls at T0 but became significantly shorter at T2. • Ar-Go parameter increased less than the controls at T2. • Results indicate that long-term use of the chin-cup appliance (>5 years) is effective in subjects with severe skeletal Class III abnormality.

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Rare Earth Magnets and Impaction — Vardimon, Graber, Drescher and Bourauel (AJO, 1991) Introduced a new, magnetic attraction system, with a magnetic bracket bonded to an impacted tooth and an intra-oral magnet linked to a Hawley-type retainer for stimulating the natural eruption of an impacted tooth into the oral cavity. • The magnetic system consisted of a magnetic bracket and an intra-oral magnet. • A miniaturized prism-shaped Nd2Fe14B magnetic alloy in an un-magnetized form was ground down (width = 2.20 mm × height = 2.59 mm × depth = 2.02 mm) to fit into an enlarged intra-bracket space, i.e. into the space created between two machined down-tie wings of a twin bracket. • Vertical and horizontal magnetic brackets were designed, with the magnetic axis magnetized parallel and perpendicular to the base of the bracket, respectively. • The vertical type is used for impacted incisors and canines. • Horizontal magnetic bracket is applied for impacted premolars and molars. Rare Earth Magnets Graber described the potential for the clinical utilization of rare earth magnets for the following purposes: • Space control (space closure/opening) • Open bite therapy (intrusion of posterior teeth) • Palatal expansion • Growth guidance (functional appliances) • De-impaction of canines and molars.

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Magnetic versus Mechanical Expansion with Different Force Thresholds and Points of Force Application —Vardimon, Graber, Voss and Verrusio (AJODO, 1987) Studied the effects of force magnitude (high vs low) and point of force application (tooth vs direct palatal endosseous pins) on palatal expansion treatment in 4 Macaca fascicularis monkeys. Animal 1 (IS) • Received an upper acrylic appliance with an expansion screw. • The appliance was bonded bilaterally from canine to 1st molar. • Thus, high forces (2033 g) were transmitted indirectly to the mid-palatal suture via the abutment teeth. Animal 2 (IM) • Received two permanent SmCo5 magnets in repelling configuration. • The appliance was bonded to the abutment teeth (canine and 1st molar). • It transmitted low forces (258 g) indirectly to the mid-palatal suture. Sliding (A) and stationary (B) acrylic housings to receive the magnets. (C) Acrylic occlusal extensions to be bonded to dental arch. (D) Horizontal tubes to receive the U-shaped bar (E) Vertical holes (F) to retain the reactivation holders (G) Teflon rings (H) to serve as barriers in the reactivation process. Animal 3 (DM) • Received a magnetic unit linked to a plate attached to the palate via 4 endosseous pins. • It transmitted low forces (258 g) directly to the palatal shelves. Animal 4 (control): received a passive sham appliance bonded to abutment teeth. Their results showed that: • Treatment time was longer in the low force, magnetically-induced appliances groups – 33 days in IS, 135 days in IM and 95 days in DM groups. • In animal IS, a diastema developed between the incisors and the force was directed superolaterally and then transmedially, thus causing

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fractures in the nasal complex and other iatrogenic sequelae. • In the magnetically-induced appliances, the force radiated supero-laterally, dissipating in the zygomatico-frontal suture, and the overjet significantly increased due to marked widening of incisive and transverse sutures. • The palatally pinned magnetic appliance produced bodily tooth movement, the greatest increase in inter-molar distance, and a superior positioning of the maxillo-palatine region. • Their results suggested reduction of conventional forces for palatal expansion by up to eight-fold, through the use of rare earth magnets. Stability of Magnetic versus Mechanical Palatal Expansion — Vardimon, Graber and Voss (EJO, 1989) Spatial stability following palatal expansion (PE) treatment was studied longitudinally on 8 Macaca fascicular is monkeys. • The sample was divided into short-term and long-term groups. • The 4 animals in each group received: • An indirect screw (IS) PE appliance (F = 2035 g). • An indirect magnetic (IM) PE appliance (F = 258 g and 360 g). • A direct magnetic (DM) PE appliance (F = 258 g and 360 g). • A sham appliance. • Direct force transmission was via pinning to the palatal shelves, indirect transmission was via abutment teeth. This study indicated that: • Transverse stability was greatest in the skeletally borne appliance. • Inter-canine distance relapse was 53% for IS and 23% for DM groups. • Inter-molar expansion was more stable than inter-canine expansion due to selective activity of circummaxillary sutures and root configuration. • Sagittal advancement and vertical superior translation were greater in the magnetic appliances with low force PE regimen. • Clinical implication – low force PE regimen can be of substantial benefit in young skeletal Class III patients with transverse maxillary deficiency.

Magnetic Strength and Corrosion of Rare Earth Magnets — Ahmad, Drummond, Graber, BeGole (AJODO, 2006) • Evaluated several magnet coatings and their effects on magnetic flux density. • Sixty neodymium-iron-boron magnets were divided into 6 equal groups—polytetrafluoroethylene-coated (PTFE), parylenecoated, and noncoated. • They were subjected to 4 weeks of aging in saline solution, ball milling, and corrosion testing. • Their results showed a significant decrease in magnet flux density after applying a protective layer of parylene, whereas a slight decrease was found after applying a protective layer of PTFE. • After 4 weeks of aging, the coated magnets were superior to the non-coated magnets in retaining magnetism. • The corrosion-behavior test showed no significant difference between the 2 types of coated magnets, and considerable amounts of iron-leached ions were seen in all groups. • The authors concluded that throughout the processes of coating, soaking, ball milling, and corrosion testing, PTFE was a better coating material than parylene for preserving magnet flux density. However, corrosion testing showed significant metal leaching in all groups. Functional Orthopedic Magnetic Appliance (FOMA) II—Modus Operandi — Vardimon, Stutzmann, Graber, Voss, Petrovic (AJODO, 1989) • Introduced a new functional appliance (FA) to correct Class II dentoskeletal malocclusions. • The FOMA II uses upper and lower attracting magnets (Nd2Fe14B) to constrain the lower jaw in an advanced sagittal posture. • In vitro, a special gauge transducer measured the magnetic attractive path and forces. • In vivo, 13 prepubertal female Macaca fascicularis monkeys received facial implants and were treated for 4 months with the following appliances: – Conventional FA (4 subjects) – FOMA II (5 subjects) – Combined FOMA II + FA (2 subjects) – Sham (control) appliance (2 subjects).

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Dr TM Graber’s Contribution to Orthodontics

1. The FOMA II consisted of upper and lower magnetic plates. • Buccal (solid line) and lingual (dashed line) 0.035-inch stainless steel arch wires formed the metal substructure. • The two arch wires were linked together by acrylic overlaying the incisor and molar crowns. • The FOMA II was designed with a magnetic inclined plane (25°). 2. The conventional FA (feedback plates) guided the mandible to a forward position by using a slanted guide bar attached to the upper plate and a lower oblique plane of the lower plate. 3. The combined FOMA II + FA appliance consisted of a labial magnetic unit and a lingual prong system. 4. The sham appliance with its passive upper and lower plates. The in vitro results showed the following: • Vertico-sagittally displaced upper and lower magnets attracted ultimately along an oblique line with a terminal horizonal slide to become fully superimposed. • The functional performance improved when the magnetic interface acted as a magnetic inclined plane. • The magnetic force was able to guide and constrain the mandible toward the constructive protrusive closure position. The in vivo results demonstrated the following: • Functional performance increased in FOMA II (22%) and in the combined FOMA II + FA (28%) over the conventional FA. • Mandibular length increased significantly in the treated animals over the control animals. • Incisor proclination was lower in magnetic appliances than in the conventional FA. • Mandibular elongation and condylar posterior inclination resulted from posterosuperior endochondral growth and by bony remodeling of the condylar neck. • No anterior displacement of the post-glenoid spine nor the articular eminence was found. The Functional Orthopedic Magnetic Appliance (FOMA) III — Vardimon AD, Graber TM, Voss LR, Muller (AJODO, 1990) • Developed an intraoral inter-maxillary appliance for the treatment of Class III

• •

•

• • • •

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malocclusions that exhibit midface sagittal deficiency with or without mandibular excess. The FOMA III consists of upper and lower acrylic plates with a permanent magnet incorporated into each plate. The upper magnet is linked to a retraction screw and is retracted periodically (e.g. monthly) to stimulate maxillary advancement and mandibular retardation. The upper plate of a FOMA III consists of a 0.031-inch stainless steel arch wire forming the metal substructure. The arch wire bypasses the premolar-canine segment to permit eruption and crosses the occlusal plane at the M1-M2 embrasure (a). The upper magnetic housing (b) is linked to a retraction screw (c). The magnetic unit (b + c) is positioned along the midpalatal line. The screw housing is linked to the plate at the M1-M2 level (d). Two guiding bars (e), attached to the plate (lingually to the central incisors and laterally to the screw housing), and restrains the magnetic unit from vertical deflection via guiding tubes (f).

Upper Plate of a FOMA III in an Experimental Animal • The attractive mode neodymium magnets used in their study produced a horizontal force of 98 g and a vertical force of 371 g. • The ratio of horizontal to vertical force vectors is dictated by inclination of magnetic interface in the sagittal plane. • The more perpendicular the magnetic interface is to the occlusal plane (sin 90° = 1), the greater is the horizontal force vector. The interaction between sutural and condylar growth sites appeared biphasic, characterized by an immediate and rapid excitation of the circummaxillary sutures followed by a delayed and slow suppression of the condylar cartilage. Maxilla 1. The target area of the protractive force was found to be localized in the pterygomaxillary fissure. 2. Three-dimensionally, the separation of the sutures at the PMF was found to diminish in inferosuperior and lateromedial directions.

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Mandible The fact that no pathologic change was found in the condylar cartilage encourages a long-term use of the FOMA III appliance, initiating treatment at an early skeletal age. • A later radiographic and histologic study by Vardimon, Graber et al (AJODO, 1994), again on nine Macaca fascicularis monkeys who were treated for 4 months with FOMA III revealed the following data: 1. The growth pattern of the cranial base (saddle angle) was not altered. 2. Midfacial protraction occured along a recumbent hyperbolic curve with a horizontal maxillary displacement and an anterosuperior premaxillary rotation. 3. Cumulative protraction of the maxillary complex was initiated at the pterygomaxillary fissure with an additional contribution provided by other circummaxillary sutures (zygomaticomaxillary s., transverse s., premaxillary s.). 4. Inhibition of mandibular length was minimal, but a tendency toward a vertical condylar growth pattern was observed. Determinants Controlling Iatrogenic External Root Resorption and Repair During and After Palatal Expansion —Vardimon, Graber, Voss, Lenke (AO, 1991) • In this study, the mechanisms controlling external root resorption (ERR) and repair were studied on 8 Macaca fascicularis monkeys. • The animals were treated with jackscrew, magnetic and sham palatal expansion screws. They were divided into short- and long-term groups. • SEM morphometric analysis found major evidence of ERR in the tooth-borne jackscrew appliance, in the long-term group, in the maxillary premolars, on the buccal and furcation root surfaces, on the mesio-buccal root and in the apical zone. • Correspondingly, the ERR mechanism is controlled by impulse (F. Δt) and the critical barrier of the PDL as primary determinants and by the environment density as the secondary determinant. • ERR is initially regulated by the force component of the impulse and, with increased duration, by the time component.

• The impairment/repair dynamics were found to be dominated by 3 principles: ERR level of irreversibility, delayed resorption response and jiggling. Repair of Orthodontically Induced Root Resorption by Ultrasound in Humans — El-Baily, El-Shamy and Graber (AJODO, 2004) • This study evaluated the effect of low-intensity pulsed ultrasound (LIPUS) on the healing process of orthodontically induced tooth-root resorption in humans. • Twelve orthodontic patients who were seeking orthodontic treatment that necessitated extracting the first premolars before mechanotherapy participated in this study. • For each patient, buccally activated springs were used to tip the maxillary first premolars buccally, with an initial force level of 50 g. • A short period of LIPUS was applied to 1 side of each patient’s mouth, with the other side used as a control. • After 4 weeks, the experimental premolars of all patients were extracted, and the premolars of 6 patients were studied by scanning electron microscopy (SEM); the premolars of the other 6 patients were studied histologically. • The SEM study showed a statistically significant decrease in the areas of resorption and the number of resorption lacunae in the LIPUS-exposed premolars. • Histologic examination showed healing of the resorbed root surface by hypercementosis. • The results of this study provide a noninvasive method for reducing root resorption in humans. Repair Process of External Root Resorption Subsequent to Palatal Expansion Treatment —Vardimon, Graber and Pitaru (AJODO, 1993) • The repair process of external root resorption (ERR) and the role of retention mechanics in enhancing ERR repair were studied on eight Macaca fascicularis monkeys that were divided equally into short- and long-term groups. Six monkeys received palatal expansion appliances, and 2 received sham appliances. • The short-term group received active treatment. • The long-term group received additional retention (4 months) and relapse (2 months)

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treatment periods with biweekly injections of individual vital dye per phase, i.e. procion red H-8B and violet H-3R (80 mg/kg B.W.), respectively. Their results showed that: • The short-term group demonstrated penetrated resorption with pulp exposure at sites with initial deficiency of the protecting odontoblastic layer (apical zone, nutrition canal). • The long-term group showed two forms of ERR repair: 1. Non-functional retarded repair cementum, comprised of overlapped incremental lines and deprived of extrinsic fibers, was delineated in severe pulp exposure. The pulp/dentin complex showed intense incorporation of procion dye in the dentinal tubuli, conceivably related to a defense response in the form of sclerotic dentin. 2. Functional rapid repair cementum, comprised of discriminated incremental lines mainly of mixed cellular cementum, with a consistent pattern of five sequential phases: the lag phase (14–28 days), the incipient phase (14 days), the peak phase (14–28 days), the steady phase (42–56 days) and the retreating phase (70 days). Sharpey’s fibers at functional ERR sites were scarce, never emerging from the dentinocemental junction, and not developing into principal fibers. The pulp/ dentin complex showed an increase in pulp stones but no formation of tertiary dentin. The apical area responded by hypercementosis in the form of apical occlusion and a displaced pulp canal. GRABER’S OTHER CONTRIBUTIONS TO ORTHODONTICS A Cephalometric Analysis of the Developmental Pattern and Facial Morphology in Cleft Palate — TM Graber (AO, 1949) • Thirty three cleft palate patients (22 males, 11 females) were studied cephalometrically. It was found that: • The maxilla in Cleft palate patient’s cases is deficient in antero-posterior, lateral, as well as vertical growth.

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• There is an abnormally large contribution of upper face height to total face height when the teeth are in occlusion, due to vertical maxillary deficiency. • There is markedly larger inter-maxillary clearance or freeway space in CP individuals when compared to normal. This suggests that while there is a bony insufficiency, the general musculature attempts to maintain a normal developmental pattern and relation of parts. • Mandibular growth on the whole appears normal. Values taken with the teeth in occlusion indicate over closure. • There is excessive lingual axial inclination of the lower incisors to the mandibular plane. • The maxillary 1st molar tends towards a distal position with reference to craniometric measurements outside the maxilla. • Surgical correction can limit the growth potential of the maxillary denture. • The clinical results of orthodontic treatment, while improving the tooth-to-tooth relationship in some cases, does not necessarily stimulate basal bone development. Therapeutic results are often unstable and have to be maintained indefinitely. A Functional Study of the Palatal and Pharyngeal Structures — Graber, Bzoch, Aoba (AO, 1959) • Using high speed roentgenographic equipment, the soft tissue morphology of normal subjects was studied during the instant of production of various consonant sounds (p, b, f, w, m). • Biometric analysis was made. Following conclusions were drawn: • Soft palate increases significantly in length from the rest to functional position. • The greatest extent of the upward and backward movement of the palate takes place at the midpoint of the posterior superior surface of the palate (mean = 16 mm). • The velopharyngeal valve is consistently closed for all the consonant sounds during normal speech production. • Slight anterior movement of the posterior pharyngeal wall is seen in 50% of normal cases. The authors concluded that the orthodontist, as well as the prosthodontist and speech

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therapist, should profit from a better appreciation of normal speech physiology.

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Postmortems in Post-treatment Adjustment — TM Graber (AJO, 1966) • In this classic article, Dr Graber stresses the need for a longer period of orthodontic management in many cases. • He says that, with the orthodontists’ dependence on pattern and growth and development, it is essential to keep patients under observation longer and observe the status of the stomatognathic system in its biologic continuum. • The concept of treating the malocclusion once and then considering it finished is unphysiologic. Thus, the philosophy of a longer orthodontic management and responsibility, with two or three shorter periods of orthodontic mechanotherapy, is more appropriate. Serial Extraction: A Continuous Diagnostic and Decisional Process — TM Graber (AJO, 1971) • Serial extraction is a guided, progressive removal of deciduous teeth ahead of the time they would normally be shed, to enlist the fundamental phenomena of adaptability and adjustment. • Dr Graber states that the technique is biologically sound, proven, and should not be considered a compromise. • In almost all instances of serial extractions, conventional orthodontic therapy is required to complete the alignment of teeth, to parallel the roots, to eliminate overbite and to effect residual space closure. However, the duration of such mechanotherapy is significantly shorter, is likely to produce less damage, and the results are more stable. Orthosurgical Teamwork — Olson, Mincey and Graber (JADA, 1975) • Using the examples of 6 patients with different malocclusions, the authors have reported on the combined orthodontic-surgical approach towards treatment. • They state that surgery and orthodontics can separately, but surely better in combination,

correct a variety of developmental jaw deformities, whether they are hereditary or traumatic in origin. • The patient is best served by this teamwork, not only during the actual mechanical and operative phases, but also during the initial diagnostic and treatment planning phases, that are every bit as important. • Proper diagnosis requires a thorough knowledge of growth and development, of cephalometric analysis, of occlusion and proper jaw relationships, and of surgical and orthodontic techniques to correct these deformities. • Here, the orthodontist, because of his training and experience in these aspects, can be invaluable to the surgeon. Post-pharyngeal Lymphoid Tissue in Angle Class I and Class II Malocclusions — Sosa, Graber and Muller (AJO, 1982) • Studied the relationship between the adenoid tissue and type of malocclusion. • Xeroradiographic lateral cephalograms were made of 80 Class I and 64 Class II/I malocclusions. • The epipharyngeal lymphoid tissue, nasopharyngeal airway, nasopharynx and certain cephalometric landmarks were measured. Their results showed that: • There is no clear-cut relationship between either Class I or Class II/I malocclusions and the total nasopharyngeal area. • Sexual dimorphism was seen: – Class I males: widening of antero-posterior dimension of nasopharynx is associated with anterior rotation of the mandible, longer maxillas, larger SNB angles, opening of cranial base angle, and increased distance from sella to PNS. Thus, these patients have more anteriorly positioned maxilla and mandible. – No association was present at all for Class II/I males. – Class II/I females: larger nasopharyngeal area is associated with longer maxillae and smaller palatal plane angles, and anterior rotation of mandible.

Dr TM Graber’s Contribution to Orthodontics

Orthodontics and Temporomandibular Disorder: A Meta-analysis — Kim, Graber and Viana (AJODO, 2002)

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• In this meta-analysis, the relationship between traditional orthodontic treatment, including the specific type of appliance used and whether extractions were performed, and the prevalence of temporomandibular disorders (TMD) were investigated. • Their data indicated that traditional orthodontic treatment did not increase the prevalence of TMD. Growth Modification of the Rabbit Mandible Using Therapeutic Ultrasound: Is it Possible to Enhance Functional Appliance Results? — El-Bialy, El-Shamy, Graber (AO, 2003) • The objective of this study was to evaluate the effect of therapeutic US on condylar and mandibular growth in the rabbit model. • Eight growing New Zealand male rabbits were chosen for this study.

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• They received therapeutic US on one side of the mandible for 20 minutes/day for four weeks. • Anthropometrical and histological evaluations revealed that US enhances mandibular growth by condylar endochondreal bone growth and consequently mandibular ramus growth. • It thus increases the mandibular condylar, ramal, and total mandibular heights in growing rabbits. Dr Thomas M Graber was certainly a pioneer amongst men. His complete devotion and love for the specialty of orthodontics is reflected in his extensive works on a myriad of topics, spanning over a period of nearly six decades. As Dr Graber’s family friend and colleague, Dr Jim McNamara noted, “Tom’s energy and enthusiasm for our profession make him a wonderful role model for future generations of orthodontists.” The passing of Dr Thomas M Graber marks the end of an era in orthodontics.

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James McNamara’s Contribution to Orthodontics For Personal Use Only Library Of School Of Dentistry.Tums

• James McNamara Analysis • Relating the Maxilla to the Cranial Base • Relating the Mandible to the Maxilla (Midface)

10

• Relating Mandible to Cranial Base

• Studies on Functional Appliances

• Dentition Analysis • Airway Analysis

• Studies on Rapid Maxillary Expansion • Studies on TMJ

Dr McNamara received his dental and orthodontic education at the University of California, San Francisco, and a Doctorate in Anatomy from the University of Michigan. He serves as the Thomas M and Doris Graber endowed Professor of Dentistry in the Department of Orthodontics and Pediatric Dentistry, Professor of Cell and Developmental Biology in the University of Michigan Medical School and Scientist at the Center for Human Growth and Development. He is the author (with artist William L Brudon) of the new text, Orthodontics and Dentofacial Orthopedics. He has maintained a private practice in Ann Arbor since 1971. He is a Diplomate of the American Board of Orthodontics and a Fellow of the American College of Dentists. In addition, Dr McNamara is editor-in-chief of the 40 volume Craniofacial Growth Monograph Series published through the University of Michigan. He has published over 180 scientific articles in refereed journals, has written, edited or contributed to 53 books, and has presented courses and lectures in 30 countries. More recently, McNamara has focused on clinical studies of the effects of orthodontic, orthopedic and surgical interventions on the growth of the face. He serves as the curator of The University

of Michigan Elementary and Secondary School Growth Study, one of the largest longitudinal studies of untreated individuals in the world. This unique collection allows the study of facial development from the early juvenile period to middle age in the same group of untreated subjects, providing a basis of comparison for ongoing clinical investigations. JAMES McNAMARA ANALYSIS Presented by Dr James A McNamara as an original article in the December 1984 issue of the American Journal of orthodontics. • He asserts that his analysis method is presented as a language, which can be used by the clinician to better identify and describe the structural relationships of the jaws, as well as to communicate easily with other clinicians as well as lay persons. • This method of analysis is derived in part from the principles of the Ricketts’ and Harvold analyses. • The James McNamara analysis is useful in diagnosis and treatment planning of the individual patient when values derived from the tracing of the patients’ head film are compared to established norms; the norms from three groups have been derived:

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James McNamara's Contribution to Orthodontics

– The Bolton study – The Ann Arbor sample (200 adults) – The Burlington sample. • This analysis consists of five major sections: – Relating maxilla to cranial base – Relating maxilla to mandible – Relating mandible to cranial base – The dentition – Airway analysis.

Normative Standards in McNamara Analysis are listed below (Table 10.1). Table 10.1: Normative Standards in McNamara Analysis

I. RELATING THE MAXILLA TO THE CRANIAL BASE (FIG. 10.1)

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Mandibular length (mm) (Co-Gn)

Lower anterior facial height (mm) (ANS-Me)

80 81 82

97–100 99–102 101–104

57–58 57–58 58–59

83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105

Soft Tissue Evaluation The nasolabial angle and cant of upper lip should be examined both clinically and cephalometrically. The nasolabial angle is formed by the intersection of a line tangent to the base of the nose with a line tangent to the upper lip. Norms for nasolabial angle according to: Ann Arbor adult sample = 102 ± 8°. An acute nasolabial angle can be a reflection of dentoalveolar protrusion, but it can also occur because of the orientation of the base of the nose. The cant of the upper lip should be evaluated relative to the vertical orientation of the face. The upper lip to nasion perpendicular angle should be: 14° ± 8.2° in females 8.4° ± 7.8° in males. Hard Tissue Evaluation In an evaluation of the position of the maxilla relative to the cranial base, two factors are considered: • The skeletal relationship of point A to the nasion perpendicular.

Midfacial length (mm) (Co-point A)

103–106 104–107 105–108 107–110 109–112 111–114 112–115 113–116 115–118 117–120 119–122 121–124 122–124 124–127 126–129 128–131 129–132 130–133 132–135 134–137 136–139 137–140 138–141

58–59 59–60 60–62 60–62 61–63 61–63 62–64 63–64 63–64 64–65 65–66 66–67 66–67 67–69 68–70 68–70 69–71 70–74 71–75 72–76 73–77 74–78 75–79

Nasion Perpendicular to Point A •

The first measurement to be made is the linear distance from point A to the nasion perpendicular. • In the composite norms for adults of both sexes in this analysis, point A is 1 mm ahead of the nasion perpendicular line. II. RELATING THE MANDIBLE TO THE MAXILLA (MIDFACE)

Fig. 10.1: Relating the Maxilla to the cranial base

• The lengths of the mandible and the maxilla (midfacial region) are related. • The effective maxillary length—line from condylion to point A. • The effective mandibular length—line from condylion to anatomic gnathion.

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• A geometric relationship exists between the effective length of the midface and that of the mandible. Any given effective midfacial length corresponds to a given effective mandibular length. • If the effective midfacial length is subtracted from the mandibular length, the maxillomandibular differential can be determined. • Ideally this differential is 20 mm for smallsized persons, 25–27 mm for medium-sized persons and 30–33 mm for large-sized persons. • Composite norms have been extrapolated from the values derived from the Bolton and Burlington samples, as well as from the Ann Arbor sample. • These norms represent a geometric relationship between effective midfacial length and effective

A

mandibular length and are not directly related to the age or sex of the individual subject. • Once the effective length of the midface is known, the effective mandibular length can be estimated. Vertical Relationship (Fig. 10.2) • Lower anterior facial height. It is measured from ANS to Me. • In well-balanced faces the vertical dimension correlates with the effective length of the midface. • Mandibular plane angle(Fig. 10.3): Angle between F-H plane and Go-Me. – Normal Value: 22°+/–4° – Higher Value: Excessive lower facial height

B

Figs 10.2A and B: (A) Vertical maxillary excess results in downward and backward positioning of the mandible creating excessive anterior facial height (ANS-M); (B) Vertical maxillary dentoalveolar deficiency causing an upward and forward positioning of the mandible and deficient lower anterior facial height (ANS-M)

A

B

Figs 10.3A and B: (A) Mandibular plane angle of 22 degrees to Frankfort horizontal in average normal individual; (B) High mandibular plane angle suggestive of excessive lower facial height

James McNamara's Contribution to Orthodontics

–

Lower Value: Deficiency in lower facial height • Facial axis angle: Angle between Posterosuperior aspect of pterygomaxillary fissure to gnathion and Line joining Basion to Nasion. – Balanced Face = 90° – Excessive vertical development, less than 90°(negative value) – Deficient vertical development, higher than 90°(positive value).

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Relating the Lower Incisor to the Mandible Anteroposterior position of Lower Incisor: Determined by using a traditional version of the Ricketts measurement of the facial surface of the lower incisor to the A-Pog line. Bolton study Norms: 1.5 mm anterior to the A-Pog Line. Ann Arbor Norms: 2.3–2.7 mm anterior to the A-Pog Line.

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III. RELATING MANDIBLE TO CRANIAL BASE (FIG. 10.4) • The relationship of the mandible to the cranial base is determined by measuring the distance of the pogonion to the Nasion perpendicular. • According to the composite norms: – In a mixed dentition (balanced face) pog lies 8 mm to 6 mm (posterior) with respect to Nasion perpendicular and moves forward with growth. – In adult male the chin position is usually –2 mm to +2, relative to Nasion perpendicular. IV. DENTITION ANALYSIS Relating Upper Incisor to Maxilla (Fig. 10.5 and 10.6) A vertcal line is drawn through point A parallel to nasion. The distance from point A to the facial surface of Upper incisor is measured → A-P position of Upper incisor Norms = 4–6 mm (Adults).

A

Fig. 10.5: Method of determining position of upper incisor relative to point A. NP = nasion perpendicular; PNP = point A vertical constructed parallel to nasion perpendicular through point A; D anteroposterior distance from upper incisor to point A (should be 4–6 mm)

B

Figs 10.4A and B: Mandible to cranial base measured from pogonion to nasion perpendicular. Tracing (A) shows normal mandible to cranial base relationship in an adult woman. Tracing (B) shows serverly retrusive mandible (–31 mm) and mildly retrusive maxilla (–3 mm)

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Upper Pharynx • The upper pharyngeal width is measured from a point on the posterior outline of the soft palate to the closest point on the posterior pharyngeal wall (Fig. 10.7A and B). • This measurement is taken on the anterior half of the soft palate outline because the area immediately adjacent to the posterior opening of the nose is critical in determining upper respiratory patency. • Apparent airway obstruction, as indicated by an opening of 5 mm or less in the upper pharyngeal measurement, is used only as an indicator of possible airway impairment. • A more accurate diagnosis can be made only by an ENT specialist.

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Fig. 10.6: Severely protrusive upper incisors (11 mm) in a protrusive maxilla

Lower Pharynx Vertical Position of Lower Incisors

• Lower pharyngeal width is measured from the intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall (Fig. 10.7A). • Average measurement is 11–14 mm independent of the age. • According to the measures derived from the Ann Arbor sample, the average value for this measurement is 10–12 mm and does not change appreciably with age (Fig. 10.8).

Evaluated on basis of existing lower anterior facial height. First, the lower incisor tip is related to the functional occlusal plane. If curve of Spee is excessive: lower incisor is to be intruded (if LAFH is normal/excess) OR lower molar is allowed to erupt and lower incisor extruded (when LAFH is inadequate). V. AIRWAY ANALYSIS Two measurements are used to examine the possibility of airway impairment.

A

B

Figs 10.7A and B: (A) Average normal upper pharyngeal airway space A, in this instance 15 mm. Lower pharyngeal airway space B measurement is 11 mm; (B) Possible upper airway obstruction; measurement A is approximately 2 mm

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functional appliance than in those wearing the tissue-borne appliance. Treatment and Post-treatment Effects of Acrylic Splint Herbst Appliance Therapy —Franchi L, Baccetti T, McNamara JA Jr. AJO 1999

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Fig. 10.8: A patient with a normal lower pharyngeal measurement

• Obstruction of the lower pharyngeal area because of a posterior positioning of the tongue against the pharyngeal wall is rare. • A greater than average pharyngeal width on the other hand suggests a possible anterior positioning of the tongue either due to habitual posture or due to tonsillar enlargement. • Clinical conditions that can be associated with a forward tongue position and/or enlarged tonsils: – Mandibular prognathism – Dentoalveolar anterior crossbite – Bialveolar protrusion of the teeth. STUDIES ON FUNCTIONAL APPLIANCES —James A McNamara Jr, Raymond P Howe, Terry G Dischinger. AJO 1990 • This study investigated the treatment effects produced by the tooth-borne (Herbst appliance) and one primarily tissue-borne (FR-2). • The results of this study indicated that both appliances had influenced the growth of the craniofacial complex in treated persons. Significant skeletal changes were noted in both treatment groups, with both groups showing an increase in mandibular length and in lower facial height, as compared with controls. • Greater dentoalveolar treatment effects were noted in the group wearing the tooth-borne

• This study evaluated the skeletal and dentoalveolar changes induced by acrylic splint Herbst therapy of Class II malocclusion. • The study showed that two-thirds of the achieved occlusal correction was due to skeletal effects and only one-third to dentoalveolar adaptations. • Both skeletal and dentoalveolar effects were mainly due to changes in mandibular structures. A significant amount of relapse in molar relationship occurred during the posttreatment period, and this change could be ascribed to the mesial movement of the upper molars. Linda Ratner Toth, James A McNamara Jr. AJO 1999 • Twin-block and FR II compared with untreated class II. • Mandibular length increase in Twin-block3 mm • Mandibular length increase in FR II- 1.9 mm. • The present study suggests, that Class II correction with the Twin-block appliance is achieved through normal growth in addition to mandibular skeletal and dentoalveolar changes. • Class II correction with the FR-2 is more skeletal in nature, with less dentoalveolar changes noted. • The present study suggests, therefore, that Class II correction can be achieved with either appliance system evaluated here. The FR-2 appliance appears to have primarily a skeletal effect, whereas, the Twin-block appliance produces both skeletal and dentoalveolar adaptations. Tiziano Baccetti, Lorenzo Franchi, Linda Ratner Toth, James A McNamara Jr. AJO 2000 • The findings of this short-term cephalometric study indicate that optimal timing for the orthodontics treatment.

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Cephalometric parameter used in McNamara analysis are summarized in this below table along with their respective normative value (Table 10.2). Table 10.2: McNamara Analysis Name of Patient _______________________________________________ Age _______ Sex ______

1.

Normal

Patient

14• (±8•) 8• (±8•) 0–1 mm

__________ __________ __________

__________ __________ Small 20–23 mm Med. 27–30 mm Large 30–33 mm

__________ __________ __________ __________ __________

Small 60–62 mm Med. 65–67 mm Large 70–73 mm 22• (±4•) 0• (±3.5•)

__________ __________ __________ __________ __________

Small –8 to –6 mm Med. –4 to 0 mm Large –2 to +2 mm

__________ __________ __________

Dentition 1 to Point A 1 to A-Po

4–6 mm 1–3 mm

__________ __________

Airway Upper pharynx Lower pharynx

15–20 mm 11–14 mm

__________ __________

Maxilla to Cranial Base Nasolobial angle No. Perp. to point A

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2.

Maxilla to Mandible* Anteroposterior Mand. length (Co-Gn) Max. length (Co-Point A) Max./mand. differential

Vertical L. ant. fac. ht. (ANS-Menton)

Mand. PL (FH-Go-Menton) Facial axis (Ba-N) = (PTM-Gn) 3.

4.

5.

Mand. to Cranial Base (Pog-Na Perp.)

Comment

Summary Conclusion

• Twin-block therapy of Class II disharmony is during or slightly after the onset of the pubertal peak in growth velocity. • When compared with treatment performed before the peak, late Twin-block treatment produces more favorable effects that include – Greater skeletal contribution to molar correction – Larger increments in total mandibular length and in ramus height – More posterior direction of condylar growth, leading to enhanced mandibular lengthening.

The Importance of the Assessment of Skeletal Maturity and the Onset of the Pubertal Growth Spurt in Individual Patients has to be Emphasized as a Fundamental Diagnostic and Decision-making Tool in Treatment Planning for Class II Malocclusion — Faltin KJ, Faltin RM, Baccetti T, Franchi L, Ghiozzi B, McNamara JA Jr. AO 2003 • The findings of the present study on Bionator therapy followed by fixed appliances indicate that this treatment protocol is more effective and stable when it is performed during the pubertal growth spurt.

James McNamara's Contribution to Orthodontics

• Optimal timing to start treatment with the Bionator is when a concavity appears at the lower borders of the second and the third cervical vertebrae (CVMS II). In the long-term, the amount of significant supplementary elongation of the mandible in subjects treated during the pubertal peak is 5.1 mm more than in the controls, and it is associated with a backward direction of condylar growth. • Significant increments in mandibular ramus height also were recorded.

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de Almeida MR, Henriques JF, de Almeida RR, Weber U, McNamara JA Jr Angle. Orthod 2005 • The results indicated that the treatment effects of Herbst produced in the mixed dentition patients were primarily dentoalveolar in nature. • The mandibular incisors were tipped labially, and the maxillary incisors were retruded; a significant increase in mandibular posterior dentoalveolar height occurred, and there was a restriction in the vertical development of the maxillary molars. • There was no difference in the forward growth of the maxilla between the two groups. • In comparison with the controls, however, the Herbst treatment produced a modest but statistically significant increase in total mandibular length. Paola Cozza, Tiziano Baccetti, Lorenzo Franchi, Laura De Toffol, and James A McNamara, Jr. AJO 2006 Two-thirds of the samples in the 22 studies reported a clinically significant supplementary elongation in total mandibular length (a change greater than 2.0 mm ) as a result of overall active treatment with functional appliances. The amount of supplementary mandibular growth appears to be significantly larger if the functional treatment is performed at the pubertal peak in skeletal maturation. The Herbst appliance showed the highest coefficient of efficiency (0.28 mm per month) followed by the Twin-block (0.23 mm per month). The coefficient for the bionator 0.17 m per month). For the activator, it was slightly lower (0.12 mm per month). The coefficient of efficiency for the Fränkel appliance, was the lowest (0.09 mm per month).

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STUDIES ON RAPID MAXILLARY EXPANSION Joyce Y Chang, James A McNamara Jr,Thomas A Herberger. AJO 1997 • The purpose of this investigation was to examine the long-term effect of the Haas-type RME on bite opening and on the anteroposterior position of the maxilla. • There was no significant difference among groups receiving rapid maxillary expansion, followed by edgewise treatment (RME), standard edgewise therapy alone (SET), or no treatment (CTRL). • The current investigation of long-term treatment effects concludes therefore that RME therapy used in the treatment of patients with Class I and Class II malocclusions does not have a significant long-term effect on either the vertical or the anteroposterior dimensions of the face. McNamara JA Jr, Baccetti T, Franchi L, Herberger TA. AO 2003 RME Followed by Fixed Appliances • In comparison with controls, a net gain of 6 mm was achieved in the maxillary arch perimeter, whereas a net gain of 4.5 mm was found for the mandibular arch perimeter. • The amount of correction in both maxillary and mandibular intermolar widths equaled two-thirds of the initial discrepancy, whereas treatment eliminated the initial deficiency in maxillary and mandibular intercanine widths. • The amount of correction for the deficiency in maxillary arch perimeter was about 80%, whereas in the mandible a full correction was achieved. Geran RG, McNamara JA Jr, Baccetti T, Franchi L, Shapiro LM. AJO 2006 • Treatment with an acrylic splint RME followed by fixed appliances produced significantly favorable short-term and long-term changes in almost all maxillary and mandibular arch measurements. • The amount of change in both maxillary and mandibular intermolar and intercanine widths fully corrected the initial discrepancies. • Approximately 4 mm of long-term relative increase in maxillary arch perimeter, and 2.5 mm additional

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maintenance of mandibular arch perimeter were observed in the TG compared with the CG. • These results suggest that this protocol is effective and stable for the treatment of constricted maxillary arches, and can relieve modest deficiencies in arch perimeter.

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Cozza P, Baccetti T, Franchi L, McNamara JA Jr. Am J Orthod Dentofacial Orthop. 2006 • The aim of this study was to investigate the effectiveness of a quad-helix/crib (Q-H/C) appliance in a group of growing subjects with thumb-sucking habits and both dental and skeletal open bites. • The Q-H/C appliance was effective in correcting the dental open bite in 90% of growing subjects with thumb-sucking habits and dentoskeletal open bites. • The average increase in overbite during Q-H/ C therapy (3.6 mm more), the maxillary and mandibular incisors had significantly greater lingual inclinations (about 4.0 degrees) associated with greater extrusion (1.4 and 1.0 mm, respectively) in the Q-H/C group. • The Q-H/C protocol produced a clinically significant improvement in the vertical skeletal relationships because of downward rotation of the palatal plane. Neuromuscular and skeletal adaptations to altered function in the orofacial region. James A McNamara, Jr. AJO 1973 • The nature of intrinsic musculoskeletal adaptations resulting from experimental alterations of the orofacial environment. • Neuromuscular adaptations. • Mandibular adaptations – changes in the growth pattern of the condylar head and compensatory migration of the dentition. (depending on the maturational level). • Maxillary adaptations – changes in the extent and vector of growth of the skeletal components.

• Pre-chondroblastic – chondroblastic layer showed responses. • Initial adaptations along the posterior border of the condyle followed by changes in the posterosuperior region. • This study demonstrated that significant adaptive responses can occur in the mandibular condyle of the juvenile rhesus monkey following alteration in the functional position of the mandible. • And that the condyle is highly responsive to changes in the biomechanical and biophysical environment of the TMJ region during growth. Kristine S West and James A McNamara, Jr. AJO 1999 • The purpose of the present study was to evaluate cephalometrically the craniofacial growth changes and adjustments that occur from late adolescence to mid adulthood in persons who had no previous history of orthodontic treatment. Mandibular and midfacial lengths as well as posterior and lower anterior facial heights had increased significantly for males and females over both time intervals. • The pattern of expression of these changes was different in the two genders: males showed an anterior rotation of the mandible, whereas females demonstrated a posterior rotation of the mandible. • Soft tissue changes also were somewhat different between genders. In males, the nose and chin grew downward and forward, with the lips generally moving straight downward. • In contrast, females had nasal growth that progressed downward and forward, and there was a slight retrusion of the lips over time. • Continued tooth eruption was noted in both genders as well. STUDIES ON TMJ McNamara, Jr. OOO 1997

James A McNamara, Jr and Carlson DS. AJO 1979 • TMJ adaptations to protrusive function. • Significant adaptive responses can occur in the mandibular condyle of the juvenile rhesus monkey following alteration in the functional position of the mandible.

• The relationship between orthodontic treatment and TMDs has long been of interest to the practicing orthodontist. • The interest in orthodontics and TMD in part was prompted in the late 1980‘s after litigation that alleged that orthodontic treatment was the proximal cause of TMD in orthodontic patients.

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• This resulted in an increased understanding of the need for risk management as well as for methodologically sound clinical studies. The findings of current research investigating the relation of orthodontic treatment and TMD are as follows:

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specific gnathologic ideal occlusion does not result in signs and symptoms of TMD. • Thus far there is little evidence that orthodontic treatment prevents TMD, although the role of posterior unilateral crossbite correction in children may warrant further investigation.

Signs and Symptoms of TMD May Occur in Healthy Persons

Conclusion

• Signs and symptoms of TMD increase with age, particularly during adolescence, until menopause and so TMD s that originate during treatment may not be related to the treatment. • Treatment performed during adolescence does not increase or decrease the chances of TMD later in life. • Extraction of teeth as a part of treatment plan does not increase the risk of TMD. • There is no increased risk of TMD associated with any particular type of orthodontic mechanics. • Although a stable occlusion is a reasonable orthodontic treatment goal, not achieving a

• The overall goal of McNamara’s research is to provide a sound biological basis for understanding how the face normally grows and how facial growth can be altered by experimental and therapeutic intervention. • His past research involved studies of both normal and experimental alterations in the growth of the facial region in a non-human primate, using the rhesus monkey as a model of human craniofacial development. • More recently, McNamara has focused on clinical studies of the effects of orthodontic, orthopedic and surgical interventions on the growth of the face.

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Andrews’ Straight Wire Appliance • Why “Straight Wire”? Overcome in the ‘Straight Wire Brackets’ • Deficiencies in the Conventional Edgewise Bracket • Variable Bracket Sitting Design, and How they are Procedures: Lawrence F Andrew’s Remedy The ‘straight wire’ appliance is an example of what a motivated person could achieve with determination and perseverance. It is a fascinating story of a man fully engaged in practice that carried out outstanding research extending into numerous projects and culminated in the development of an appliance that has profoundly affected the practice of orthodontics. After his graduation in 1959, Laurence F Andrews (Fig. 11.1) was looking for a topic to write a thesis that was required for certification by the American Board of Orthodontics. The theme that he chosed was the prevalent quality of American orthodontic practice with respect to static occlusion. He started an assessment of posttreatment orthodontic study models exhibited at the meetings of American Board of Orthodontics, Angle Society and Tweed Foundation. Although the records indicated that the patients’ occlusion had shown remarkable improvement over the original condition, and there were few common findings (such as class I molar occlusion, normal overjet, absence of cross bites and incisor rotations), many other features like angulations and inclinations of various teeth and curve of Spee were quite disparate. These cases had been judged as the outcome of excellent treatment by

11

• Straight Wire Appliance Brackets for Different Clinical Situations • Straight Wire Appliance (SWA)

examiners appointed at these prestigious societies, and yet they differed considerably. Therefore, Lawrence F Andrews concluded that the then existing criteria for measuring the

Fig. 11.1: Lawrence F Andrew

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Andrews’ Straight Wire Appliance

quality of finishing were ill defined and needed to be revised. He rightly decided that the answer to his question rested in the nature’s ideal cases. Thus started his tryst with the normal, which he latter on called optimal occlusion. He collected orthodontic study models of 120 non-treated individuals whose occlusion was considered to be ideal by him and his peers. With a keen eye and logical mind, he picked out the six consistent features related to the clinical crowns, which were common to all the study models. He named these as the six keys to normal occlusion. They describe the characteristics of best static natural occlusion as related to molar relation, angulations and inclinations of the teeth and stipulate that there should be no rotations and spaces, and the curve of Spee should be flat. He published his results in the American Journal of Orthodontics in the year 1972. The article since has attained the status of mandatory reading for anyone aspiring to become an orthodontist. The uniqueness of Andrews’ study was that the tooth positions were referenced from clinically visible teeth crowns (or, more specifically, the labial and buccal surfaces of clinical crowns) and not from the long axis of the teeth, which can be judged only from the radiographs. Further, the referents selected were such that optimal occlusion based on them obviated the need to use articulating paper to check the interfacing of occlusal surfaces or view the occlusion from the lingual side. The most important of the referents was the facial axis of clinical crown, formerly termed long axis of the clinical crown. For all the teeth other than the molars, it is the most prominent ridge on the crown’s face; while for the molars it is the dominant groove on the crown’s face. From the facial perspective it appears as a straight line. From the mesial or distal perspective it is perceived as a straight line tangent to the midpoint of the crown’s face. The midpoint of facial axis of clinical crown is named as the facial axis point (FA point), which is formerly termed long axis point. It is used for assessing the positions of the teeth as also for placing the brackets accurately on the teeth. When all the teeth are correctly positioned, the plane joining the FA points of all the teeth is named as Andrews’ plane.

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Andrews later stated in his interview that he considered finding the facial axis of clinical crown as his most significant contribution to orthodontics, because it can be used for both angulations and inclination. Also it has a reliable correlation with planes of crown at all times and with the mid-transverse planes of all the crowns in an arch when the teeth are correctly positioned. “Without it there would have been no six keys and no straight wire appliance.” Andrews reexamined the treated cases applying the criteria of the six keys. This study revealed that most of them failed to attain many, if not all, keys. The failures were, in a descending order of occurrence, errant angulations of the teeth; interarch relations, inclinations of the teeth, rotations of remaining teeth, excess curve of Spee and persistent spaces. Lawrence F Andrew started analyzing the causes for the above short comings and came to the conclusion that the standard edgewise appliance had too many deficiencies to obtain consistent results. These were in the following form: 1. Variability in wire bending from operator to operator and even with the same operator. 2. Deficiencies in the standard edgewise bracket design. 3. Variations in the bracket sitting procedures. Lawrence F Andrew’s next study was aimed at exploring the conceptual feasibility of developing an appliance, which would facilitate obtaining the six keys consistently in treated cases. It consisted of numerous measurements on the plaster casts of non-orthodontic normal occlusion. These ascertained the natural anatomic similarities (earlier named ‘tendencies’ by Wheeler) in human dentitions. Specifically, they were related to constancy of position and shape within each tooth type, and consistency of relative size of crowns within an arch. The conclusions from this study were: 1. Most individuals have normal teeth regardless of whether they have normal occlusion or malocclusion. Abnormally shaped crowns in the rest of the persons are generally amenable to restorative procedures to normalize them before orthodontic treatment is started. 2. Each normal tooth type (such as the central incisors, lateral incisors, cuspids, etc.) is

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similar in shape from one individual to another. 3. All the teeth in any individual’s mouth are generally proportionate though they may vary in size from person to person, i.e. all the teeth tend to be large, medium or small. 4. The size of normal crowns within a dentition has no effect on the relative prominence of their facial surfaces, or the curvatures both vertical and horizontal of the labiabuccal surfaces on which the brackets will be placed, or on the location of contacts between two teeth types. Also, optimal crown angulation or inclination as well as interarch relation are not related to the size of the crowns and hence are attainable, whatever may be the size of the crowns. 5. When the upper and lower jaws are proportionate and properly related, it is always possible for the teeth to be brought in optimal occlusion. The study thus paved the way for creating a new appliance by taking advantage of the anatomic similarities in the human dentition, and by recognizing the fact that similarities exist in the positions of the normal teeth when they are optimally occluded. Andrews developed his appliance to address all the above mentioned problems with respect to variability in wire bending, deficiency in bracket design and variable bracket sitting procedures. WHY “STRAIGHT WIRE”? The term straight wire in the present context refers to an archwire that is given the arch form and often the curvature to open the bite, but which is free from the first, second or third order bends. It is a ‘formed’ but ‘unbent’ archwire. Lawrence F Andrew’s endeavor to develop an appliance that would permit the use of such an archwire by transferring most of the tooth guidance functions from the archwires to the brackets (by modifying the bracket design), was based on the following reasoning: 1. Some of the bends in an archwire are needed for effecting first, second and third order tooth movements (Lawrence F Andrews termed these as the primary bends). It is difficult to make these bends precisely for affecting the exact amount of tooth movement. Hence, if precise tooth guidance

is built in the brackets instead of depending on the wire bends, more consistent results could be obtained. 2. Other wire bends (secondary bends) are required for compensating for faulty placement of the brackets or the deficiencies in the bracket design. One example is the buccal root torque in the posterior region of the archwire that is needed in the conventional edgewise treatment, which is given not to effect any torquing movement but to avoid unintentional torque. Standard edgewise brackets placed on the curved buccal surfaces of the posterior teeth, on receiving a flat (untorqued) archwire, would create an unintended torque on the teeth in a crown buccalroot lingual fashion that is generally undesirable. Buccal root torque in the archwire prevents this from happening. These wire bends are needed in all the successive archwires and in almost all the patients. This repetitive wire bending could be eliminated if the bracket design shortcomings are corrected by suitable modifications (for example, by having builtin torque in the brackets itself to remedy the above mentioned situation). 3. Even for the same operator, the bends placed in the successive archwires are likely to vary. They will certainly be different for different operators. Since every bend in the archwire not only causes some action but also has a reaction, the results from such differing bends are unpredictable and often lead to undesired tooth movements. Additional secondary wire bends will be required for overcoming them. 4. Some of the bends influence the actions of other bends, e.g. torque in the anterior section of the archwire negates the tip by a ratio of 1:4 (wagon-wheel effect). Accurate wire bending to negate such ill effects is extremely difficult but provision could be made in the bracket design to overcome them to a large extent. However, it should be noted that in only few cases, the entire treatment could be completed using ‘straight’ archwires. Andrews stated that straight wires in progressively larger dimensions take the treatment close to the treatment objectives, but in many cases would require some wire bending in the final archwires to fine tune

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Andrews’ Straight Wire Appliance

the results. The analogy he gave was of reaching some destination far away. You need not walk all the distance. The straight wire appliance is like an airplane that takes you to the nearest airport quickly and effortlessly. Final wire bending is like walking the last few kilometers. Deficiencies in the conventional edgewise bracket design, and how they are overcome in the ‘straight wire brackets’ The conventional edgewise brackets are identical for all the teeth except some mesiodistal width differences. However, different teeth have different relative prominences, angulations and inclinations. This necessitates giving first, second and third order bends in the archwire. 1. Bracket base is perpendicular to the faciolingual axis, and the slot is cut parallel to the facio-lingual axis. This leads to targeting the bracket slots to different inclinations and occlusogingival levels. When placed on different teeth with varying curvatures, the latter may result in functional interferences. 2. Because the bracket bases are not contoured occlusiogingivally, they can rock on the curved crown facial surfaces, which further affect the slot inclination and occlusogingival positions. Similarly, lack of mesiodistal base contour could lead to rocking of the brackets, which will affect the rotational control. 3. Because the brackets are not angulated, second order bends in the archwire become necessary. Angulating the brackets themselves does not solve the problem because of rocking potential of the bracket base. 4. Stems of equal prominence necessitate the first order bends such as the bends required between the upper central and lateral incisors. Similarly, because the molar tubes or brackets have no offset built-in, first order bends become necessary mesial to the molars. Andrews rightly observed that what stands between the orthodontist and the teeth are the brackets, and therefore the brackets should be designed and affixed on the teeth such that their planes should reflect the planes of the teeth crowns. Hence he set about designing a new system of edgewise brackets (and a more precise way of attaching them on the teeth. His brackets

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(which he described as fully programmed brackets) had the following features: 1. Every tooth type had a specifically designed bracket, which had precisely builtin angulations and inclinations to eliminate the second and third order bends. The magnitude of angulations and inclinations for different teeth (‘prescription’ values in degrees) were derived from his study of normal occlusion. 2. Unlike in the conventional edgewise brackets, in which the slots are perpendicular to the vertical edges of the bracket, the slots were cut at an angle to the vertical edges for attaining the built-in angulation in the bracket. This obviated the need to rotate the brackets for angulating them. 3. The bases of the brackets were inclined (the angle of inclination precisely matching the inclination of the facial plane of the respective crown at the FA point) in order to effect the torque needed for the particular tooth type; the bracket slots were not torqued within the bracket body. In other words, the torque was built in the bracket bases and not in the face of the bracket. This made it possible to make the mid-transverse planes of each crown and bracket stem and slot, coincide, and also to align the mid-transverse planes of all the crowns and bracket slots so that they coincided with Andrews’ plane when the teeth were correctly positioned. 4. The thickness of the brackets stem was varied according to the facial prominence of each tooth, thus eliminating the need for the first order bends. The bracket bases were made such that the slot in every bracket was perpendicular to the mid-sagittal plane of the crown. This necessitated a built-in offset in the maxillary molar tubes or brackets. 5. The bracket bases were contoured both occlusogingivally and mesiodistally, (compound contouring) according to the facial surface anatomy of each tooth type to eliminate rocking of the brackets on the teeth; since bracket rocking in the occlusogingival direction would affect the built-in torque, and bracket rocking in the mesiodistal direction would affect the rotational control. Thus it became possible to use flat unbent archwires in the appliance through most part of

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History of Orthodontics

the treatment. The treatment could be started with small diameter wires, which would flex in the brackets on malpositioned teeth. The resilient wires, while regaining their original shape and form, would correct the malpositions to some extent. As one gradually moves to bigger diameter archwires, they would progressively align the teeth till a full size ‘straight’ archwire, could passively fit in all the brackets. Two types of bracket configuration were originally made available. The vertical edges were always parallel to the facial axis of clinical crown, while the horizontal edges were perpendicular to the vertical edges in the square type brackets and at a different angle in the rhomboid shaped or so-called ‘diamond’ brackets. The latter type bracket became more popular since the horizontal edges could be well aligned with the incisal edges. Some other features called the convenience features meant for increasing the ease of the operator such as marking on the brackets to identify them, and gingival tie wings on the posterior teeth extended laterally for ease of ligation were added to the brackets. Similarly, for comfort of the patients some features were incorporated, as for example, the facial aspects of the incisor and canine brackets being curved and parallel to the crown’s facial surface so as to reduce irritation to the lips. Some more features named auxiliary features such as power arms, hooks, face-bow tubes, tubes for utility arches and rotation arms were also added. VARIABLE BRACKET SITTING PROCEDURES: LAWRENCE F ANDREW’S REMEDY Many authors earlier had suggested different landmarks for bracket locations on the teeth. Lawrence F Andrews felt that the traditional referents for angulation (long axis of the crown or the tooth, incisal edges for incisors and cusp tips for other teeth, marginal ridges, contact points, etc.) were neither reliable nor practical. Similarly, inclination referents viz. long axis of crowns or teeth were unsatisfactory. Additionally, the inclination of the bracket slots at varying heights on these axis would vary because of the curvature of the facial surface. Thus, a location of the landmark at a specified

distance from the incisal edge or the cusp tip would cause variation of slot inclination depending on the crown heights of the same type but different size teeth. Lawrence F Andrews emphasized that the accurate placement of the brackets was an integral part of the straight wire appliance. He suggested a bracket sitting procedure, which was aimed at targeting the slot within two degrees and 0.5 mm of the precise placement over the slot site (This is the area on a tooth that would accept the bracket such that the bracket slot would receive a ‘straight’ archwire passively when the tooth gets optimally positioned). He demonstrated that most of the people are able to mark the midpoint of a line about 10 mm in length (a figure close to the length of facial axis of clinical crown of a maxillary central incisor) to the accuracy of within 0.5 mm. Further, they can also judge the parallelism of two or more lines within the accuracy of two degrees. Hence he reasoned that it should be possible for anyone with average skill to draw with a pencil the facial axis of clinical crown of all the teeth, mark their midpoints and align the midpoint of the base of each bracket with the facial axis point in such a way that the sides of the brackets are parallel with the facial axis of clinical crown. This is done by placing the brackets on the crowns straddling the facial axis of clinical crown with the vertical components of the brackets (viz. the vertical edges of brackets and the tie wings) parallel to the facial axis of clinical crown and the horizontal midpoint of the brackets equidistant from the end points of the facial axis of clinical crown. This would provide the accuracy needed in using the full potential of the fully programmed brackets. STRAIGHT WIRE APPLIANCE BRACKETS FOR DIFFERENT CLINICAL SITUATIONS Andrews initially introduced brackets for the treatment of non-extraction cases, with an ANB differential of less than five degrees, which he referred to as the standard brackets. Subsequently he developed brackets for extraction cases. There was one standard (non-extraction) bracket for every tooth except for the incisors, that had three, and the maxillary molars, that had two. The differing features were built-in

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Andrews’ Straight Wire Appliance

inclination for the incisor brackets and angulations, and offset angles for the molars. All other features remained the same. The upper and lower incisor inclinations were different for different skeletal types. For skeletal class I, class II and class III, the upper central incisor inclinations were 7, 2, and 12 degrees, the upper lateral incisor inclinations were 3, -2 and 8 degrees, and for all mandibular incisors the inclinations were –1, 4 and –6 degrees, respectively. For maxillary first molars, the angulation and offset were 5 and 10 degrees, for class I molar finish occlusion, while these were 0 and 0 degree for class II molar finish occlusion. The brackets for extraction cases were developed in a more elaborate fashion. Series of brackets were developed for different combinations of extractions, ANB differentials, and anchorage requirements. As the teeth are translated, they tend to tip mesiodistally and rotate into the extraction sites since the force acts at the brackets away from the center of resistance, both in the lateral as well as occlusal perspectives. In addition to these tendencies, the maxillary molars during translation also tend to tip during translation on account of the drag created by the prominent lingual root. Hence the relevant existing features of the brackets were altered or new features were added to counter these effects to an extent that would overcorrect them. Depending on the amount of translation required, the built-in angulation for the canines and premolars was varied. For teeth undergoing distal or mesial translation, 2, 3 and 4 degrees were added to or subtracted from the corresponding angulations of the standard brackets for minimum (up to 2 mm), moderate (2 to 4 mm) and maximum (4 to 6 mm) retraction respectively. This was meant for giving the counter mesiodistal tip. Anti rotation adjustments were built in the extraction series to prevent the teeth from rotating into the extraction site. This was in the form of deviation of the mesiodistal axis of the slot from its normal (perpendicular to the midsagittal plane) position by 2, 4 and 6 degrees respectively for minimum (less than 2 mm), moderate (2 to 4 mm) and maximum (4 to 6 mm) retraction. For maxillary molars needing translation, the inclination values were altered (in addition to

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counter rotation and counter mesiodistal tip) to neutralize the buccal crown-tipping tendency. The additional (negative) inclination was four, five and six degrees for minimum, moderate and maximum translation. For mandibular molars, only counter rotation and counter-mesio-distal tip were added. The canine, premolar and molar brackets tubes acquired attached ‘power arms’ to move them in a bodily manner instead of permitting any tipping (The usage of these was originally envisaged and the term originally coined by Calvin Case. Andrews retained the name in his honor). The length of power arm was adjusted such that the amount of moment generated from it, when added to the moment created by the built-in angulation for counter tip, would equal the moment arising from application of the mesially or distally directed force on the tooth, thus nullifying the latter. All these modifications were bound to create an impression of the necessity of keeping a very large inventory of brackets. However, Andrews argued that there are only 12 treatment plan possibilities for each arch, which are met by a mixture of some standard and some translation brackets. Hence depending on one’s practice requirements, one could keep the standard and commonly required translation brackets in stock and order for the remaining as and when required. STRAIGHT WIRE APPLIANCE (SWA) Lawrence F Andrews made some interesting remarks when he introduced the straight wire appliance to the profession. He was candid to admit that he did not consider the appliance as the ultimate one (“Will there ever be one?”). He further emphasized that although he had his own treatment philosophy and mechanics, his appliance was not meant to serve only his way of treatment, but was for universal use to suit any philosophy and mechanics employing edgewise brackets. He felt that his appliance could successfully treat about 90 percent of cases leaving out the 10 percent of extreme cases (which would need surgical orthodontics). As was mentioned earlier, the SWA did not gain universal acceptance instantly. Although majority of the edgewise practitioners changed

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History of Orthodontics

over to some form of pre-adjusted edgewise appliance by eighties, there were some who voiced serious misgivings. Further, many researchers critically examined the concept of the SWA, and found several flaws in the concept itself. The comments/observations of some of the prominent critics is summarized below. The main drawback of the SWA is that it overlooks biological variation in the anatomy of teeth of different individuals (this criticism would hold true for other versions of preadjusted edgewise appliances also). Dellinger, Vardiman, Lamberts, Germane and other have discussed this aspect. They used more sophisticated gadgets to study the crown surface curvatures (‘profile’) of different teeth. Dellinger used an optical comparator. Germane et al used magnified projections of the X-ray pictures of extracted teeth for making the measurements. Dellinger argued that the basic data should have been collected from individuals having malocclusion and not from ideal occlusion casts as was done by Andrews. One of the important features of SWA (and other pre-adjusted edgewise appliance) is the torque built in the brackets, which ideally should eliminate third order bends in the archwire. A uniform torque value in the bracket slots for any given tooth of all the patients is based on the premise that individual teeth of any given type (e.g. right upper central incisors or left mandibular second premolars, etc.) in all the patients would exhibit identical curvatures of facial surfaces. Only then, at a particular height on any type of tooth (e.g. at the facial axis point) brackets with properly contoured bases would fit in identical manner. The above mentioned authors have challenged this axiom. According to them this curvature could vary by as much as 5.2 0 to 10.40 for teeth with low variation and 12.80 to 25.60 for teeth with high variations. Such variations are bound to affect the torque values in most of the individuals. Therefore, use of prescribed bracket torque value may improve care in some patients but not the others. Treatment must be tailored to the biologic variation presented by each patient. This implies that the third order bends will be often required in most of the patients. Andrews had laid great stress on the consistency of the long axis point (later renamed

as facial axis point). This is also not accepted by these authors. Dellinger found it erratic and inconsistent. Germane et al also questioned Andrews’ contention that the facial surface contour is more consistent when long axis. point is used to locate the brackets and that the clinicians can place the brackets within an error of ± 2 degrees torque. The colum angle, i.e. the angle between the long axis of crown and the long axis of root differs from tooth to tooth and also for the same tooth in different persons. In class II division 2 cases the central incisors have a more acute collum angle than that seen in class II division 1 cases. Hence, even when crowns are correctly positioned (which is difficult on account of earlier mentioned reason) root placement will vary. Teeth with more acute collum angle will be placed closer to the palatal cortical plate in some cases even pressing against it. What effect the variation in root placement will have on the health of the teeth or stability of the results is not known yet. Different vertical growth patterns have different inclines of occlusal plane with respect to the cranium. The inclination value of the maxillary incisors are preadjusted with respect to the occlusal plane. While the angle of U1 to SN remains almost same in all groups, that between U1 to OP varies in high, average or low mandibular plane angle cases. Hence, a uniform built-in torque value for all the patients would place the upper incisors in positions other that optimum in high or low angle case. The upper incisors would be placed more upright or more proclined respectively in these cases. Such cases would require different torque values for correct placement of these teeth. Dellinger made a scathing attack on SWA. He stated, “Clinicians are being saved not by what the SWA does but by what it does not do” (since less than full size wires are used). And further “If full sized unbent archwires are placed in the mouth and are allowed to totally work out, the results would be erratic, inconsistent and clinically unacceptable”. There is at least some truth in this comment because Andrews stated, in his interview published few years later after the above criticism appeared, that his preference is for 0.022 brackets and that the largest wire he uses in these brackets

Andrews’ Straight Wire Appliance

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is 0.018" X 0.025" (He does not use full size wires, not even the NiTi wires). Schudy also made comments similar to Dillinger- “Placing a lot of torque in the upper incisor brackets and then never using it by not filling the brackets is an admission that it is not right for some of the patients”. He also pointed out the possibility of abuse of the appliance by the general dentists. “It (the SWA) does not place the teeth in their proper position automatically as it allegedly is supposed to do. It provides an easy way for the general dentist to try to do orthodontics, believing that it automatically produces good results” (JCO Aug 92). Perhaps a balanced view of the contradictory opinions can be found in the

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article of Ross et al that summed up neatly the place of SWA in modern orthodontics. “The straight wire appliance should not be considered an inappropriate tool. It is an important step forward in orthodontic mechanotherapy that has maximum effectiveness on average or good skeletal patterns. It is clear that the concept of ‘one appliance fits all’ defies normal biologic variation among orthodontic patients. Hence, skilled orthodontic care is still needed in spite of technologic advances”. Whatever inventions have occurred from his time to till date in orthodontics is purely on the basis of Andrews Angle’s keys to normal occlusion.

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Evolution of Orthodontic Appliances

• Brackets – Metal Brackets – Plastic Brackets – Ceramic Brackets – Weldable Brackets – Bondable Brackets – Ribbon Arch Brackets – Modified Ribbon Arch/ Brackets in Begg Technique – Tip Edge Brackets – Edgewise Brackets – Preadjusted Edgewise Brackets – Lingual Brackets – Self-ligating Brackets – Single Width Bracket – Twin Brackets

– – – – – –

Lewis Bracket Steiner Bracket Broussard Bracket Lang Brackets Jaraback – 1963 Roth – 1976

12

• Manufacturing of Archwire

• Methods of Straightening of Orthodontic Wires • Properties of Archwire – Pseudoelastic Effect – Thermoelastic Effect • Bands – Strength of the Wire – Formability • History of Archwires – Solubility And Weldability – Gold – Friction – Stainless Steel – Environmental Stability – Nickel–Titanium Alloys – Shape Memory Effect – Beta–Titanium or TMA or Can Wire • Auxiliaries – Cobalt-Chrome-Nickel Alloy • History of Orthodontic Materials – Optiflex Archwire – Use in Dentistry – Multistrand Archwires – Uses in Orthodontics

Man has long enhanced his appearance. Evidence dates back some 3000 years. Archaeologists have discovered mummified remains with crude metal bands wrapped around individual teeth with catgut thought to have been used to apply forces. Later in 400-500 BC, Hippocrates and Aristotle both considered ways to straighten teeth. The Etruscans were using appliances to maintain space and prevent collapse of the dentition; while in a Roman tomb in Egypt, a researcher found a number of teeth bound with a gold wire, the original ligature wire. At the time of Christ, Aurelius Cornelius Celsus first recorded the treatment of malaligned teeth using finger pressure.

Despite all this evidence and experimentation, until the 1700s the most aesthetic though not effective appliance remained the finger. The French surgeon, Pierre Fauchard the “Founder of Modern Dentistry” described procedures for aligning the teeth, including: filing them, manipulating them with forceps, and then tying them with thread to a silver or gold “bandeau”. A contemporary of Fauchard, Etienne Bourdet, dentist to the King of France, went a step further and recommended the extraction of first premolars to maintain symmetry of the jaws. He also used the first and more aesthetic lingual appliances. The discovery of vulcanite, when combined with gold wire springs and screws, allowed the

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Evolution of Orthodontic Appliances

use of removable appliances to induce individual tooth movement. By 1937, the discovery of acrylic had allowed translucent acrylic plates to replace black vulcanite.

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Edward H Angle (1855–1930), the “Father of Modern Orthodontics” developed the first widely adopted system for correcting malocclusions using brackets soldered to the labial of metal bands. Thus the Edgewise system was born.

1. Weldable brackets 2. Bondable brackets III. Depending on technique for which they are used 1. Ribbon arch brackets 2. Begg modified ribbon arch brackets 3. Tip-edge bracket 4. Edgewise brackets 5. Pre-adjusted edgewise brackets 6. Lingual brackets

BRACKETS AND BANDS

Metal Brackets

Until the early 20th century, 14 to 18 carat gold was the principle metal used for constructing orthodontic brackets and bands. However, with the metallurgical developments of World Wars I and II appropriate forms of stainless steel became available. The introduction of stainless steel allowed the development of progressively smaller appliances. The road to smaller appliances had begun and it was significantly accelerated with Buonocore’s direct bonding of resin to enamel and Newman’s use of epoxy resin in 1965 to directly bond brackets to the labial surface of teeth.

• Metal brackets (Fig. 12.1) are routinely used in orthodontic practice of which steel brackets are the most frequently used. • Titanium brackets are recently introduced and have high biocompatibility and low friction.

BRACKETS • Brackets are passive components which provide a means of transferring tooth-moving forces from archwires, elastics and other active components of fixed orthodontic appliance. • They can be welded to the bands which are then cemented onto the teeth (weldable brackets). Bondable brackets being increasingly used in recent years, although weldable ones have to be opted in some cases. • Brackets manufactured from a variety of materials are available and they can be of various designs suitable for different orthodontic techniques. Brackets can be classified in a number of ways as listed below: I. Depending on material used for manufacture 1. Metal brackets a. Gold b. Stainless steel c. Titanium 2. Plastic brackets 3. Ceramic brackets II. Depending on mode of attachment

Advantages of Metal Brackets a. b. c. d. e.

They can be sterilised. They can be recycled. They resist deformation and fracture. Exhibit less friction with the arch wire. They are comparatively less expensive.

Disadvantages a. Easily noticeable, metallic brackets are aesthetically not pleasant. b. They may corrode and cause staining of the teeth. Plastic Brackets Plastic brackets (Fig. 12.2) initially made from acrylic and later from injection moulded polycarbonate, were introduced in the 1970s. They promised significantly enhanced aesthetics;

Fig. 12.1: Metal brackets

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History of Orthodontics

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Fig. 12.2: Plastic brackets

unfortunately, problems of staining, odour, timedependent creep, and breakage soon became apparent. Permanent deformation, or creep, occurs when a material is subjected to a constant load over an extended period. It is particularly important for thermoplastic materials such as polycarbonate and polyurethane resins. Compensation for the lack of strength and rigidity is reinforcement with ceramic or fiberglass fillers and/or metal. This has improved their popularity. Plastic brackets made of polycarbonate and other related materials were introduced to improve aesthetics. However, they are not preferred as they have a number of disadvantages such as: 1. They tend to get discolored easily especially in patients who smoke or drink coffee, tea, etc. 2. They have poor dimensional stability 3. Their slots tend to distort 4. There is a high amount of friction between plastic bracket and metal archwire. Ceramic Brackets Ceramic brackets (Figs 12.3A and B) were first introduced in the 1980s. There are two basic forms; monocrystalline, which is almost transparent; and polycrystalline which is tooth colored. Offering better aesthetics than either stainless steel or polycarbonate; they also exhibit good resistance to wear and deformation, as well as color stability. However, they have problems when compared to stainless steel brackets including greater frictional resistance, bracket breakage, iatrogenic enamel damage, and

A

B Figs 12.3A and B: Ceramic brackets

difficulty in debonding the brackets. These problems are being overcome and the brackets now offer quite an aesthetic alternative to stainless steel. Transparent and opaque tooth colored ceramic brackets are available and are generally made of alumina or zirconium based products. Advantages 1. They are highly a esthetic not easily noticeable. 2. Resist discoloration unlike plastic brackets 3. Dimensionally stable, do not distort in oral cavity Disadvantages 1. They are very brittle and thus tend to fracture easily during active treatment and also while debonding. 2. Exhibit greater friction at wire/bracket interface than metallic brackets 3. High cost of material.

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Evolution of Orthodontic Appliances

A

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Fig. 12.5: Bondable brackets

B Figs 12.4A and B: Weldable bracket

Weldable Brackets (Figs 12.4A and B) • They are either welded or soldered to the band which is then cemented over. The weldable brackets have metal flanges on the base to facilitate welding. Bondable Brackets (Fig. 12.5) • They are directly bonded onto the teeth using bonding adhesives • Base of these brackets generally exhibit meshwork or indentations to facilitate bonding with the adhesive material.

Fig. 12.6: Ribbon arch brackets

Ribbon Arch Brackets (Fig. 12.6) • Ribbon arch brackets had a simple design with occlusally facing vertical slot in it • They were used in ribbon arch technique. Modified Ribbon Arch/Brackets in Begg Technique (Fig. 12.7) • Begg technique uses modified ribbon arch brackets in which the vertical is facing gingivally rather than occlusally • This modification allowed easy tipping of the teeth.

Fig. 12.7: Modified ribbon arch/brackets in Begg technique

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History of Orthodontics

Fig. 12.10: Preadjusted edgewise brackets

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Fig. 12.8: Tip edge bracket

Fig. 12.11: Lingual brackets Fig. 12.9: Edgewise brackets

Tip Edge Brackets (Fig. 12.8)

Preadjusted Edgewise Brackets (Fig. 12.10)

They are used in tip-edge technique. The bracket design is a modification of the conventional Edgewise bracket where two diagonally opposite corners of the conventional edgewise bracket slot are removed and a vertical rectangular slot is also added.

They are modified edgewise brackets with in-built tip, torque angulations incorporated in their design.

Edgewise Brackets (Fig. 12.9) Edgewise brackets and their modifications becomes the mainstay in orthodontic practice today. They are employed in edgewise technique. Most Edgewise brackets have rectangular horizontal slot with four wings, two gingival and two occlusal. The rings help securing archwire in the slot and brackets may also have hooks for attaching auxiliaries such as elastics. They are available as a set of different brackets for different teeth.

Lingual Brackets (Fig. 12.11) Lingual brackets are arguably the most aesthetic, appliance of all as they are placed on the lingual aspect of the teeth. Despite being made of stainless steel they are virtually invisible to the casual observer. Unfortunately these appliances are generally considered to be more time consuming to both place and adjust, and therefore attract a significant premium in cost over conventional labial brackets and are initially more uncomfortable than labial brackets. Consequently fewer patients are attracted to them.

Evolution of Orthodontic Appliances

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Fig. 12.13: Vertical Slot Lewis bracket Fig. 12.12: Self-ligating brackets

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Self-ligating Brackets (Fig. 12.12) Self-ligating brackets were first popularized in the 1980s, one of the earliest being the speed system. They are more aesthetic as they have a much smaller labial “footprint” than other stainless steel brackets of the day and no longer require the use of either steel or elastomeric ligature ties. Stainless steel self-ligating brackets have been shown, in-vitro, to have the lowest static and kinetic frictional forces. Polycarbonate selfligating brackets generate significantly greater static and kinetic frictional forces than stainless steel self-ligating brackets but are comparable to conventional stainless steel brackets. Single Width Bracket • Narrow width - ineffective tooth rotation. • Angle - gold eyelets - on the orthodontic bands. • Two brackets - single tooth. Twin Brackets • Two edgewise brackets on a common base. • ‘Siamese twin bracket’ by Swain • Space between two brackets is 0.050 inch, which 0 equal to the width of one bracket.

Fig. 12.14: Tooth that is badly rotated, the wing in the direction of the rotation can be removed. The bracket can then be positioned properly, with the remaining wing serving to rotate the tooth into proper position

• Decreased amount of archwire, Interbracket span and resiliency • Closing loop archwires • Second order bends Lewis Bracket Lewis bracket is wedge shaped bracket, which places the tie wing close to the tooth occlusally and further away gingivally. Vertical Slot Lewis Bracket (Fig. 12.13) • A vertical slot 0.020 × 0.020 inch. • Uprighting springs - correct axial inclinations

Advantages • Rotational control : mainly by deflection of arch wire • Positive control Disadvantages • 10 percent play of archwire

Additional Benefit For tooth that is badly rotated, the wing in the direction of the rotation can be removed (Fig. 12.14). The bracket can then be positioned properly, with the remaining wing serving to rotate the tooth into proper position

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History of Orthodontics

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Fig. 12.17: Joseph Johnson introduced twin arch appliance

Fig. 12.15: When a Lewis or Steiner bracket is completely tied into a cuspid, there is a tendency to flatten the curvature of the archwire

Fig. 12.18: Oren A Oliver introduced labiolingual appliance

Lang Brackets (Fig. 12.16)

Fig. 12.16: A Lang bracket avoids this effect, while retaining the rotation wing capability

Steiner Bracket (Fig. 12.15) • Flexible rotation arm. • The flexibility arms gives a rotational effect .

• By Dr Howard Lang • Placed in large, round surfaced teethmaxillary and mandibular cuspids. • Contoured so that bracket fits beautifully on most cuspids. • When a Lewis or Steiner bracket is completely tied into a cuspid, there is a tendency to flatten the curvature of the archwire. A Lang bracket avoids this effect, while retaining the rotation wing capability.

Broussard Bracket • Graffard Broussard modified edgewise bracket • 0.0185 × 0.046 inch vertical slot • II accept a doubled 0.018 inch auxiliary wire

Later Modifications • Burstone modified canine bracket - a vertical tube - retraction assemblies.

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Evolution of Orthodontic Appliances

• Edgelock bracket and Hanson speed appliance bracket: • These brackets eliminate the need for ligature ties as they possess self-ligating mechanism. In 1938 Joseph Johnson introduced twin arch appliance (Fig. 12.17) In 1940 Oren A Oliver introduced labiolingual appliance (Fig. 12.18) Holdaway – 1952

Fig. 12.19: Self-ligating bracket

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Angulated brackets on the teeth adjacent to extraction spaces aid in: • paralleling the roots . • setting up posterior anchorage. • obtaining correct axial inclinations or ‘artistic positioning’ of the teeth. John J Stifter – 1958 • U S patent - designing an edgewise bracket comprising a male and female component Ivan Lee – 1960 Torqued slots - regional and basic edgewise bracket. To eliminate - adding torque - anterior portion of the upper archwire. Manufacturers – 1960: raised the base of lateral incisor. Raised bases eliminated the need for lateral offset bends. Jaraback – 1963 Described the use of torqued brackets • Andrews Straight Wire Appliance - 1970 • Two varieties. • The standard prescription for non extraction cases and ‘Translation series’ for extraction cases . • Limitations of conventional Straight Wire bracket • Moving teeth apex first generates maximum anchorage resistance • Torque control - unwanted reciprocal torque reaction in adjacent teeth • Full expression of torque not achieved“Torque slop” due to play between bracket and arch wire Roth – 1976 • Bracket set up containing modifications of tip, torque and rotations. • Purpose of Roth - over corrected tooth positioning.

Fig. 12.20: Peter C Kesling

• Appliance in position. It is impossible to position the teeth precisely into occlusion. • After appliance removal, the teeth will shift slightly. Self-ligating Brackets • Self-ligating brackets (Fig. 12.19) don’t need tie wires or elastic ligatures to hold the archwire onto the bracket. They are held on by a “trap door” built into each bracket. • As early as 1935, the idea of a self-ligating brackets began to take shape. • Over the years many designs were patented, but few were commercially available until Ormco created the edgelock system in 1972. • Nowadays, we have a number of self-ligating choices, such as Orec’s speed braces, Ormco’s Damon system, GAC’s In-Ovation, and Adenta’s Evolution. Peter C Kesling (Fig. 12.20) decided to combine both the techniques. He modified a straight wire

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History of Orthodontics

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bracket, to create tip edge bracket and differential force technique. In this technique initial crown tipping was done followed by controlled root uprighting with straight arch wires (differential tooth movement with straight arch wires). Therefore it is known as the “differential straight arch technique”. Archwire slot permits initial crown tipping mesially or distally and faces horizontally, the slot and bracket are termed Kesling determined that: • It is necessary for each tooth to tip either mesially or distally but not in both directions • All teeth tip distally except those distal to the extraction sites, which tip mesially • Anchor molars should remain upright throughout Rx. • Diagonally opposite corner were removed • Permits desired distal crown tipping • Preadjusted in three dimensions• tip, torque, in and out built in • Slot size - 0.022" × 0.028 Alexander – 1983 Vari–simplex discipline: • Vary - variety of bracket types used; • Simplex - KISS principle (Keep it Simple Sir) Discipline was chosen rather than the appliance. • Based on edgewise philosophy Creekmore – 1993 Slot machine onies solution to the • Inaccuracies of bracket placement, • Anatomic and biologic variations, over correction for tissue rebound and relapse and • Mechanical differences of preadjusted edgewise orthodontic appliance

Fig. 12.21: Bands

Table 12.1: The stainless steel strips are available in different widths and thickness to suit different teeth Teeth

Band Thickness Band Width (Inches)

Incisor Canine Premolar Molar

0.003 0.003 0.003 0.0050.006

Figure

0.125 0.150 0.150 0.0180.018

• It orients the archwire slot to relative to the facial surface of each tooth on the model. BANDS Bands (Fig. 12.21) are passive components that provide space for fixing various attachments onto the teeth. They are generally made of soft stainless steel. The stainless steel strips are available in different widths and thickness to suit different teeth (table 12.1). Weldable brackets, buccal tubes and other auxiliary attachments are soldered or welded over the bands, which are then cemented around the intended teeth. Availability 1. Custom-made bands are fabricated using band materials which are available in the form of spools. 2. Preformed seamless bands are available in different sizes which can be directly cemented around the tooth. Preformed bands are increasingly being used in recent years. ARCHWIRES History of Archwires By the 1960s, gold as an archwire had largely been replaced. It gave way to thinner, more resilient stainless steel wires such as Wilcox’s Australian wire. However, in 1974, Unitek patented its nitinol (Nickel Titanium Naval Ordnance Laboratory) wire having the lowest modulus of elasticity and most extensive deactivation range of any equivalent cross sectional wire of the time. This allowed the application of light forces over a protracted range. By 1986, “superelastic” alloy wires that undergo stress induced change in their crystal form had been developed. These offered significant advantages over nitinol. The range of wires available to orthodontist has been futher

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extended by the addition of various other elements (Table 12.2) including cobalt-chromimum. Betatitanium and, in 1994 copper. Copper NiTi changes its crystal form at a specific temperature. Most recently, a nickel free wire, titanium-niobium has been introduced. With these new wires, especially the super elastic wires, it is no longer necessary to incorporate multiple loops, significantly enhancing aesthetics as well as comfort. A number of manufacturers now offer NiTi and stainless steel archwires coated with tooth colored material to enhance their aesthetics, especially when combined with ceramic brackets. Unfortunately, these coatings tend to wear away with time; however, further research should see this resolved. The search for improved aesthetics is leading us down the road of fiber reinforced composites. These materials are not yet clinically useful as archwires; however, they have been incorporated into bis-GMA ribbons and bonded, as strips, to multiple teeth, to provide retention and also anchorage, reducing the number of conventional brackets required. Manufacturing The manufacture of metal alloy wires involves making an ingot followed by rolling and drawing: 1. Making the Ingot: This involves pouring of molten metal into a mold. The result obtained is the cast wire to produce an ingot. A magnified view of this ingot shows crystals or grains; it is mainly this grain structure, which ultimately controls the significant mechanical properties of the final wire. Grain formation depends on the rate of cooling and the size of the ingot. 2. Rolling: The formed ingot is rolled into a long bar. This is done with the help of a device termed as the roller. During rolling, the individual grains retain their identity throughout this process. Each grain gets elongated proportional to the ingot. The squeezing and massaging actions of roller increases the strength by causing the grains to mesh and interlock. The rolling procedure is continued till the crystals are so locked that they can no longer adjust. At this point, the rolling is interrupted and the metal structure is annealed by heating it to a suitable

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temperature. At the annealing temperature, atoms become mobile enough to move about and thereby get relieved of some of the internal stresses, which had been introduced during rolling. When the metal cools down, the grain structure is seen to be uniform. 3. Drawing: This is the final step, wherein this small cross section wire is further drawn into its final size. This is a more precise step in which the wire is pulled through a small hole in a die. The hole is slightly smaller than the starting diameter of the wire; so that the wall is squeezed uniformly from all sides as it passes through. The cross section of the wires are the same as the die. Methods of Straightening of Orthodontic Wires Following are the two methods of straightening of wires; 1. Spinner straightening. 2. Pulse straightening. 1. Spinner straightening: In this type of straightening, the wire is pulled through a bronze roller, which torsionally twist the wires. However, this mode does not produce wires as mechanically efficient as the the ones produced by ‘pulse straightening’. Disadvantages: Disadvantages of spinner straightening are as listed below • Deformation • Decreased yield stress value. 2. Pulse straightening: This is a recent and more accepted method of straightening of wires, which employs special machines to straighten wires which lead to: • Maintenance of the yield strength • Smooth finish, which would be also, beneficial as it produces less friction. Pulse straightened wires have superior qualities in comparison to spinner straightened wires as shall be discussed in the following section on stainless steel. Basic metallurgy: At this juncture, it is mandatory to understand briefly the metallurgical properties. 1. Metal: According to the Metals Handbook (1992); a metal is defined as ‘an opaque lustrous chemical substance that is a good conductor of heat and electricity and, when polished is a good reflector of light’. 2. Alloy: An alloy is defined as ‘a metal containing two or more elements, at least one of which is

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a metal, and all of which are mutually soluble in the molten state’. 3. Alloy system: ‘An alloy system is an aggregate of two or more metals in all possible combinations’.

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Metallic Bonds and Crystalline Structure Metallic bonds imply the primary ionic interaction, which holds the metal structure. Atoms with free valence electrons as the metal atoms are able to lose their outer shell (valence) electrons and form a positive ion. The free electrons are able to move about in the metal space lattice and they are termed as an ‘electron cloud’. The electrostatic attraction between the positive ions and the electron cloud forms the ‘metallic bond’. It is this metallic bond that is responsible for luster, conductivity properties and ability of the metal to deform plastically. A regular crystalline configuration is typical for metals. This is referred to as ‘space lattice’ or ‘crystal’ (grain). The common lattice configurations are: 1. Simple cubic. 2. Body-centered cubic or ‘BCC’, e.g. austenite NiTi. 3. Face-centered cubic or ‘FCC’, e.g. austenite SS. 4. Body-centered Tetragonal ‘BCT’, e.g. martenisitc SS. 5. Close packed Hexagonal, e.g. martensitic NiTi. It can be inferred from the above examples that the lattice configurations (in turn, the grain structure and their orientation) play a significant role in determining the ultimate mechanical properties. Cast versus Wrought Metals • Generally, all metals and their alloys originate from castings. A cast metal which is plastically deformed, either by machining or working, is termed as a wrought metal. • Cast structures are close to equilibrium conditions and are incorporated in some dental applications. However, the orthodontic wires are in the wrought form. Wrought metals have a fibrous structure with extremely elongated crystals. Also this structure exhibits enhanced mechanical properties like increased tensile strength and hardness.

• Because of this, the strength values could be altered by the phenomenon of either work hardening or heat treatment. This could be either beneficial (for example: the formation of ‘dead’ ligature wires) or could be deleterious (properties of a wire may be lost during soldering procedures) and should be kept in mind. Solidification of Metals Liquid state: The liquid or ‘molten state’ represents a multitude of random atoms or molecules surrounding numerous unstable atomic aggregates. This can be seen in the solidification curve as shown in the: If a metal is allowed to cool, it first cools down uniformly (as shown by the portion A-B). After this there is a gradual increase in temperature (till B), also known as the latent heat of solidification. The portion below the fusion temperature (B-B’) is termed as super cooling. It is during this period that the crystallization of the metal begins. This takes place around ‘nuclei’; also termed as embryos. B-B1 → Super cooling Tf → Fusion temperature This nucleus formation can either be homogenous or heterogeneous. This eventually leads to ‘grain’ or crystal formation. It is at the Grain boundary that the areas of lattice imperfections can exist. Lattice Imperfections and Dislocations As would have been seen in the solidification of metals: • Crystallization does not occur in a uniform manner and some lattice positions may be ‘vacant’ or ‘overcrowded’. These are termed as “lattice imperfections”. Dislocations are defects along a particular path in a polycrystalline structure. e.g. edge dislocation. • Dislocations tend to build up at grain boundaries, greater stress is required to produce greater slip. Thus, the material becomes stronger, harder and less ductile. This is termed as the phenomenon of ‘strain hardening’ or ‘work hardening’. • The ultimate result of strain hardening is fracture. Heat Treatment Heat treatment is the thermal processing of an alloy for a length of time above room temperature but below its solidus temperature.

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Quenching: A process wherein the metal is cooled rapidly from an elevated temperature. The Heat treatment procedures are carried out for the following reasons: a. Preservation of a phase at room temperature, which is stable usually at higher temperatures. b. Rapidly terminate a process that only occurs at elevated temperature.

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Types of Heat Treatment 1. Stress relief: This refers to a ‘low’ temperature heat treatment to relieve the stresses due to strain hardening. Cobalt-chromium alloy is very responsive to stress relief. It also, improves ductility. 2. Annealing heat treatment: This employs a heat treatment at a substantially higher temperature as compared to the stress relief. Consists of three phases: i. Recovery. ii. Recrystallization. iii. Grain growth. 3. Age hardening heat treatment: It is a long term process in which the temperature is slightly lesser than the anneal temperature. The metal is then cooled rapidly by quenching. PROPERTIES OF ARCHWIRE Different types of archwire, right from gold to till date invention in archwire, are explained below with their properties. Archwires are one of the active components of fixed orthodontic appliances, which when used bring about various tooth movements (tipping, bodily, torque, rotational and vertical movements)

through the medium of brackets and welded buccal tube on the palatal aspect of the molar bands. Gold Before 1950’s, gold and other precious alloy combinations like platinum and palladium with gold and copper were routinely used for orthodontic purposes. Gold and gold alloy archwire exhibit excellent formability, environmental stability and biocompatibility. Angle’s Ribbon arch appliance utilized a gold platinum alloy combination as the ‘archwire’. However, their popularity lost ground due to two main reasons: a. The marginal properties and cost factor involved. b. Advent of stainless steel or the ‘rust free’ alloys. Stainless Steel Stainless steel (Fig. 12.22) was introduced by Wilkinson in 1929. Stainless steel archwire (Table 12.2) exhibit adequate strength, high resilience, formability, high stiffness, biocompatibility and economic feasibility. The drawback of these archwires includes high modulus of elasticity; more frequent activations are required to maintain the same force level. Nickel-titanium Alloys (Fig. 12.23) Nickel titanium alloyl also known as nitinol, (Nickel titanium Naval Ordnance Laboratory) was invented by William R Buchler at Naval Ordnance Laboratory. The main advantage of this

Table 12.2: Classification of archwires I. Based on material used 1. Gold and gold alloys 2. Stainless steel 3. Nickel-titanium alloys 4. Beta-titanium 5. Cobalt–chromium- nickel alloys 6. Optiflex archwires II. Based on cross-section 1. Round 2. Square 3. Rectangular 4. Multistranded

Fig. 12.22: Stainless steel

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braided or twisted and may have three strands or six strands. The main advantage of these arch wires is that they exhibit increased flexibility. Physical Properties of Wire The first group of properties is concerned with the elastic behavior which represents the internal stress/strain in the wire. This is produced by an external force deflecting the wire, the stress being the internal load and the strain the internal distortion. 1. Stiffness/Springiness

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Fig. 12.23: Nickel-titanium alloy

Optiflex archwire was invented by MF Talass in 1992. Optiflex archwires are composed of clear optical fibers and are therefore highly aesthetic. The drawback of these archwire is that they cannot receive sharp bends.

i. Pseudoelastic effect: When an austenitic wire is placed in the mouth and deformed by forcing it into the misaligned brackets, the pseudoelastic effect is induced. This transforms the austenitic alloy into a martenstic state which, as the teeth align, gradually reverses to the austenitic state. ii. Thermoelastic effect: Martensitic-active alloys are stable at room temperature, but when raised to mouth temperature, the material changes into an austenitic state which exhibits shape memory. iii. Martensitic stabilized alloy (e.g Unitek’s original nitinol): The alloy, introduced in 1970 by Andreasen. It is stabilized by introducing a certain amount of work hardening during processing and does not show true memory shape properties. Austenitic-active Alloy: “Active “ means that it exhibits the shape memory, in this case of the pseudoelastic type, the shape memory effect being induced by stress distorting the arch wire in malaligned teeth. Examples of superelastic Niti are Titanol from Forestadent and Nitinol SE from Unitek. Martensitic-active Alloy: Again this exhibits shape memory, but of the thermally activated variety. This alloy is stable at low temperatures but when is placed in the mouth, and the temperature increased to mouth temperature, it exhibits the shape memory effect. Examples of thermally activated Niti are Neo Sentalloy from GAC and Nitinol XL from Unitek.

Multistrand Archwires

2. Range of Deflection – Spring Back

Multistranded archwires are made up of number of thinner wires. They can be round or rectangular,

The range of wire is the distance it will bend elastically before permanent deformation occurs.

alloy over others is the high elasticity and shape back memory. The drawback of these archwires is that they cannot be neither welded nor soldered, and cannot receive bends or loops or helices. Various phases of NiTi, like the austenitic-active, with pseudoelasticity and the latest being superelastic Cu-NieTi were brought out. Other varieties like martensitic active alloy or thermoelastic NiTi alloy also evolved. The credit for introducing the superelastic NiTi goes to Fujio Miura and to Dr Rohit Sachdeva for introducing Cu-NieTi. Beta-titanium or TMA or Can Wire Goldberg and CJ Burrstone invented beta-titanium and it is also known by TMA or CAN wire. The main advantage of these arch wires include high range of action, high spring back, receive bends, loops and helices, and they can be welded or soldered. Cobalt-chrome-nickel Alloy Cobalt- chrome-nickel alloy is also known as elgiloy. These wires exhibit excellent formability, joinability, spring back and biocompatibility. Optiflex Archwire

Evolution of Orthodontic Appliances

If the wire is deflected beyond its yield point, it will not return to its original shape. 3. Strength of the Wire The strength of a wire is important because it determines the maximum force it can deliver. The above three properties are related by the formula: strength = stiffness X range. 4. Formability This is the amount of permanent deformation a wire can withstand before it breaks. 5. Solubility and Weldability

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Stainless steel can be soldered and welded, but NiTi cannot. Miura recently reported a method of soldering nickel-titanium wires. TMA is weldable as described by Burrstone. 6. Friction The laboratory understanding of friction is not relevant to the clinical situation. Because every time the patient bites together, the tooth is liable to move a small distance in all three planes of space. More important is the concept that the two components, bracket and wire, may damage each other as they moved across their surfaces. This is borne out by the fact that it is difficult to slide teeth with ceramic brackets along a wire, as the abrasiveness of the ceramic notches the surface of the metal. 7. Environmental Stability Any material used for the construction of wire must be stable in the oral environment. This has been one of the limitation aesthetic. 8. Shape Memory Effect The shape memory effect exhibited by the more recent nickel-titanium wires has revolutionized the selection of wires for appropriate tooth movement. The wires manufactured for orthodontic purposes are composed of an alloy of nearly equal parts of nickel and titanium. The shape memory effect is brought about by a change in the internal crystal formation from the martensitic phase with a hexagonal crystal structure to or from the austenitic phase with a cuboids crystal structure (Kusy, AJO Sep 1991). The shape in crystalline structure can be brought about by either: a. Stress, as in the pseudoelastic effect in the Austenitic Active Alloy.

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b. Heat, as in the thermoelastic effect in the Martensitic-active alloy where the transition temperature is between room and mouth temperatures. AUXILIARIES Brass wire was initially used to ligate the arch wire to the band/bracket combination. However, by the 1960s, the thinner and more aesthetic stainless steel had replaced it as the ligature tie of choice. The advent of polyurethane materials has seen the introduction of aesthetic colored elastomeric modules to ligate the arch wire to the bracket. While offering good aesthetics when initially placed these modules are prone to discoloration and breakdown over time and so must be regularly replaced. They also tend to increase the friction between the bracket and the archwire. Nevertheless, their ease of placement and appeal to younger patients has ensured their general use. The latest innovation to the orthodontist’s aesthetic armamentarium is the sequential clear plastic aligner. The principles of this process were actually developed by kesling in 1945. However,it did not achieve more widespread use until invisalign combined the technique with 3D computer graphic and CAD/CAM technology to allow phased movement of multiple teeth to correct mid to moderate malocclusions. Since invisalign appeared a number of other companies have released similar products, including an Australian company, Clear Smile. Unfortunately, these appliances are not suitable for treating all malocclusions. Those with significant crowding or spacing, and/or interarch discrepancies (such as Class II and III relationships) often cannot be treated properly with these systems alone. Similarly, individuals with very short crowns and younger adolescents where teeth are not fully erupted are generally not suitable. Although some extraction treatments are being carried out they are not normally as suitable as non-extraction cases. Precise alignment and finishing with these systems can be more difficult compared to traditional fixed appliances so that a compromise result may need to be accepted. Further, they are still somewhat visible on the labial surface and over the incisal edges. However, clear aligners are considerably more aesthetic than traditional braces.

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History of Orthodontics

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HISTORY OF ORTHODONTIC MATERIALS Baptized with a name resulting from the contraction of the words “elastic” and “polymer”, elastomer is an umbrella term which encompasses materials which resist distortion and resume their original shape or volume. Classified according to their chemical structure, however, materials which are not necessarily flexible are still called elastomers. Their resilience has been exploited since antiquity. A century and a half after Fauchard’s use of silk, the first elastomer, rubber, allowed the upgrade of simple ties to gradual movements. This started for rubber a career which was not challenged for another century. Returning from Columbus’ second voyage, Michele de Cuneo reported in 1495 the strange custom “Indians” have to milk trees (latex means milk in Latin). In 1521, Hernando Cortes reported that Aztecs use this coagulated and dried milk to make balls for game and to waterproof textiles. In 1750, Francois Fresneau was the first to describe the tree which is now known as Hevea brasiliensis. The tree was called by the indigenes caa (tears) ochu (wood), i.e. the tree which sheds tears. This gave in French its current name, “caoutchouc”. Its name in English came from the famous scientist Joseph Priestley who described the material in 1770 as “excellently adapted for wiping from paper the marks of a black lead pencil”, in other words, a good ”rubber”. A similar product is gutta percha, extracted from another tree, Pallaquium gutta, which grows in Southeast Asia. The first attempt to commercialize the new material were deterred because it softened when heated and was partially soluble in water. It was not until 1839 when Charles Goodyear accidentally discovered “sulfur cross-linking” that rubber became a substitute for the omnipresent plastics. Soon, rubber became precious, and Brazil was fast to monopolize it. Henry Wickham succeeded, however, in smuggling the nuts of the tree to England. Starting 1976, England developed large rubber plantations in Ceylon (Sri Lanka) and Malaya (Malaysia, Indonesia). An invention with important consequences was that of J Dunlop who, in 1888, invented the pneumatic tires for bicycles. The extension of this idea by the burgeoning industry of automobiles made

chemists worldwide try to find a substitute for this natural polymer of isoprene (C5H8)n. Success occurred in 1910 when Karl Dietrich Harries, in Germany, polymerized with the help of sodium (Na), 2,3 dimethyl Butadiene. This rubber substitute, which received the name Buna, was followed by the invention of Buna-S (S standing for styrene) by K Ziegler in 1927. In the U S, a sulfur-substituted elastomer was invented by J C Patrick in 1930, and produced under the name Thiokol. The next year, a chlorine-substituted one, invented by F J A Nieuwland and W H Carothers, was launched by Dupont Company under the name Duprene (name changed today to Chloroprene or Neoprene). Otto Bayer invented polyurethanes, in Germany, in 1937. While the latter may not represent a major category of elastomers for the general use, these most interesting for orthodontics. In the recent years, polyurethanes have become increasingly important due to advances in telechelic polymers (from tele, distance, and chele, claw, in Greek). These polymers (especially polyols) contain reactive end groups which can be used to further increase their molecular weight (mw), or to generate other copolymers with a wide range of properties. Usually, as the molecular weight). Increases, the more valuable are the polymers. The above series of discoveries has led to a diminished share of consumption for natural rubber (only 35% among all elastomers). Not only that the plantations in Southeast Asia are both expensive to maintain and subject to weather conditions, but the substitutes prove to be better and by far more versatile. Use in Dentistry While maxillofacial prostheses were described by Ambroise Pare’ (1517-1590), their massive use was determined by the two world wars. While the elastomers used years ago were mainly vinyl plastisols (plasticized polyvinyl chloride), today polyurethanes, as such or modified with acrylics, and silicone rubbers (HTV, high temperature vulcanized) are preferred. After minor uses of elastomer, in the making of dams, cups, points, special filling materials (gutta percha), a major impact was prompted by the spread of AIDS. This has led to a new

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assessment of the cross-infection procedures, in which gloves were essential. Their routine wearing during treatment became mandatory in the U S following OSHA’s regulations and FDA’s alert of March 1991. Among the elastomeric impression materials used in large amount are the polysulfides, the “addition” and “condensation” polysiloxanes, and the polyethers. All of these are identified by the American Dental Association (Specification 19) as “non-aqueous elastomeric dental impression materials”. The advantage of these elastomers is related to their hydrophobicity, which renders them both accurace and physically and chemically stable. Polyethers are less water repellent and therefore less dimensionally stable in the presence of humidity. This reflects also on their biocompatibility, since these are not inert and can lead to tissue irritations whenever the material is left in the sulcus. Likewise, “condensation” polysiloxanes are less accurate due to reasons which we will examine later. Uses in Orthodontics In addition to the elastomers generally used in dentistry, some particular uses and developments are specific to orthodontics. Thus, while water-based alginates are used in dentistry for study and record models, in orthodontics these are the preferred impression materials. A similar case is that of composites, which are used in dentistry as restoratives, filling materials, onlays and inlays, while in orthodontics, as adhesives. Alginates the insoluble salts rather than polymers, alginates are of low cost, convenient and enough accurate for most orthodontic operations. Their advantage resides in a gel structure which can resume its shape when the impression is made over undercuts. Succeeding the agar-agar impression materials (colloidal suspensions in water which can be reused), alginates is commonly classified as “irreversible hydrocolloids”. Both before and after gelation, alginates are altered by heat and water: in water presence, these materials expand: in its absence, they contract (syneresis). As a result, alginate

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impressions have a limited life, even if kept in “humidors”. Elastics, elastomeric auxiliaries recalled by the famous Case-Angle controversy (Angle attributed their first use to Baker, instead of Case), the first use of intermaxillary elastics has been documented to date as early as 1880. Initially used to exert interarch forces, today elastics are used to close spaces within the arches, hold archwires in brackets and act as force-delivery systems for retraction, protraction, tipping, intrusion, extrusion and rotation. Natural rubber, the first elastomer used for such purposes, has lost considerable ground in the last years. Due to proprietary “secrets”, it is difficult to make a correct estimate. The chemical nature of the elastomers used is often withheld, as are some characteristics like the thermal behavior (thermoset vs thermoplastic). At the recent A A O Annual convention in Denver, none of the exhibitors selling gloves knew the material these were made of (the alternative was “latex” or “non-latex”). Polyurethanes are now preferred due to their superior properties such as biocompatibility, better tensile and tear strength, and higher elasticity modulus and abra-sion resistance than the best natural rubber. A review of their properties has been recently published. Unfortunately, all elastomers lose 50 to 70 percent of their initial force during their first day of application, and after three weeks, only 30 to 40 percent of it is left6. To compensate for this diminished force, stronger elastics have to be used. To prevent possible damage, these are prestressed in advance to 50 to 100 percent of their length. Unfortunately, this leads to a lack of certitude when it comes to know the force applied. Functional appliances used as early as 1902 for Robins’ monobloc, Vulcanized rubber was for long time the only material available for functional appliances. Tooth positioners, bite planes, chin cups, oral screens, wedges, cushions and elastic straps can all be made of elastomers. As it will be shown, that some feels soft or hard is just a matter of cross-linking which is adjustable as needed.

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History of Model Analysis • Carey’s Analysis – Procedure – Inference • Pont’s Index – Drawback of Pont’s Analysis • Linderharth Index • Korkhaus’ Analysis • Howe’s Analysis—1954 – The Procedure • Bolton’s Analysis – Procedure – Determination of Overall Ratio – Determination of Anterior Ratio • Cast Analysis: Symmetry and Space

• Alignment (Crowding), Space Analysis – Principles of Space Analysis • Arvey Peck, Sheldon Peck— 1972 • Huckaba’s Analysis • Hixon and Old Father Method—1958 • Marvin M Tanaka, Lystle E Johnston in 1974 – Short Method—TanakaJohnson – Procedure in the Maxillary Arch – Modifications • Nance Analysis – Procedure for Mandibular Arch—1976

Orthodontic diagnosis and treatment planning is done by taking into consideration the tooth material, skeletal and muscle balance and growth potential. Among the various decisions taken, an important decision is the one taken for or against extraction of certain teeth to achieve the desired results. Model analysis is one of the essential diagnostic aids. Study models help us to visualize the patient’s occlusion from all aspects and also help us in making the necessary measurements of the teeth and the dental arches and basal bone. Most of the model analysis suggested by various authors does not correlate the findings of model analysis with their

•

•

• •

• •

13 – Long Method – Problems Total Space Analysis—1978 – Anterior Area – Middle Area – Posterior Area Wylie – Commenting on Model Analysis Kesling Model Analysis Martinek Analysis – Comparative Analysis of Howes, Rees, Kesling and Strayer Suwannee Luppanapornlarp 3d Model Analysis

diagnostic aids such as cephalogram and OPG and hence diagnostic value of such independent model analysis is questionable. Model analysis provides us with valuable information and when it is correlated with other diagnostic aids will help us in diagnosing and planning treatment for a case. Among other benefits, model analysis provides a means of evaluating the amount of space required for proper alignment of teeth; by allowing accurate assessment of Arch length—Tooth material discrepancy. Various methods of model analysis have been described and appropriate analysis must be selected for a given case.

History of Model Analysis

CAREY’S ANALYSIS Arch length—Tooth material discrepancy is one of the important causative factors of malocclusion. Carey’s analysis is aimed at determining the extent of the discrepancy. Carey’s analysis is performed on the mandibular cast. If the same analysis carried out on the maxillary arch, then it is called as Arch Perimeter Analysis.

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Procedure 1. Determination of arch length: The arch length anterior to the mandibular first molars is measured using a 0.012 inch soft round brass wire which adapted to the model of the mandibular arch so that one end engaged first permanent lower near the marginal ridge. The wire is next passed over the buccal cusps of the premolars, then over the normal cuspal position of the cuspid, then over the anterior teeth at ridge center and finally around the same course on the opposite side, ending in the mesiobuccal line angle of the lower first permanent molar of the other side. The wire is cut at this point and straightened, and the length is recorded. • In case of proclined anteriors, the soft round brass wire is passed along the cingulum of anterior teeth. • In case of retroclined anteriors the soft round brass wire is passed labial to the anterior teeth. • In case of well aligned anterior teeth, the wire passes over the incisal edges of the anterior teeth. 2. Determination of arch width/tooth material: Tooth material is determined by measuring the mesiodistal width of the teeth anterior to the first permanent molars (incisors, canines and premolars) at the maximum contour using bow divider. 3. Determination of the discrepancy: The discrepancy refers to the difference between the arch length and tooth material. Inference 1. Non-extraction case: If the discrepancy is 2.5 mm or less, it indicates minimal tooth

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material excess, which can be managed by proximal stripping. 2. Extraction of second premolar: If the discrepancy is 2.5–5 mm. second premolar may need be extracted. 3. Extraction first Premolar: If the discrepancy is more than 5 mm, then extraction of first premolar is advised. PONT’S INDEX Pont in 1909, proposed a method of predetermining the ideal arch width which has become to be known as Pont’s index. However, he felt that the method of measuring teeth to determine arch width was not the only factor to consider in orthodontic treatment planning. He also stressed the assessment of facial profile, determination of Angle classification, relationship of upper and lower jaws to one another and the midline as important essentials to be considered. Pont devised a method of predetermining an “ideal” arch width based on the mesiodistal width of the crowns of the maxillary incisors. Pont suggested that the ratio of combined incisor to transverse arch width (as measured from the center of the occlusal surface of the teeth) was ideally 0.8 in the bicuspid area and 0.64 in the first molar area. He also suggested that the maxillary arch can be expanded 1 to 2 mm more during treatment than the ideal to allow for relapse. In recent years there has been an unfortunate revival of the use of the Pont’s index in a most sloppy manner. Its only occlusal guide Researchers at the University of Washington applied the pont’s index to patients who had undergone complete orthodontic treatment and were out of retention for at least 10 years. No permanent teeth had been extracted in any of the patients. They found very poor correlations between the combined maxillary incisor width and the ultimate arch width in the bicuspid and molar areas, and concluded that measuring the mesiodistal width of incisors to predetermine maxillary bi-molar and inter bicuspid width is of no value. Mandibular arch form and mandibular intercanine diameter have been repeatedly found to be more reasonable treatment guides for both mandibular and maxillary ultimate arch width

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History of Orthodontics

than the Pont’s index. It’s of little use in rational treatment planning. In an interesting prelude to the index itself, Pont noted that the mesiodistal width of the maxillary central and lateral incisors could be used to predict the mesiodistal width of the maxillary canines in normal dental arches. He sugested that half the mesiodistal diameter of central plus the mesiodistal diameter of lateral would generally, equal the mesiodistal width of the canine. Pont did not indicate the size of the sample used to determine the proposed index, but did state that they were of French nationality only. For each normal dental arch, he suggested that a constant relationship existed between the width of four upper anterior teeth and the width of the dental arch in premolar and molar area. All his measurements and predictions were related to the maxillary arch and did not include an assessment of the mandibular arch. Pont determined a constant ratio between 1. The width of the four maxillary incisors 2. The width of the maxillary arch as measured from the center of the occlusal surface of the first premolars and first molars. In the ideal dental arch he concluded that the ratio of combined incisors width to transverse arch width was 0.8 in the premolar area and 0.64 in the molar area. In orthodontic procedure Pont suggested that the maxillary dental arch should be expanded one or two millimeters more than that found in normal occlusion to allow for relapse. Drawback of Pont’s Analysis JA Stifter in 1958, tested Pont’s analysis in ideal and normal class I dentitions. Cases with slightly slipped contacts, minor rotations and insignificant deviations from perfect occlusion were used, but were considered in a group separately from ideal sample, a significant correlation existed between the combined maxillary incisors widths and the inter molar and inter premolar width. No corresponding correlation was found for normal group. The sample consisted of French nationalities. Hence Pont’s index universal validity is questionable and analysis does not taken into consideration and the alignment of teeth. Hotz in 1961, suggested that deviations from Pont’s index may be related to long and narrowly

shaped dental arches. He concluded that due consideration must be given to the shape of the skull in assessment of arch form and width. LINDERHARTH INDEX Linder Harth G in 1961, on a study on Rhineland population proposed index values of 85 and 64 rather than Pont’s values of 80 and 64. KORKHAUS’ ANALYSIS Korkhaus used Linder Hart’s measurements and introduced a third measurement from the midpoint of the inter premolar line of upper arch to a point incision between the incisal edges of upper central incisors. For a particular width of incisors there is a specific value of the distance from the incision to the interpremolar line according to Korkhaus. If the perpendicular distance from interpremolar line is more than ideal, then the anterior teeth are proclined, if it lesser than the ideal then the teeth are retroclined. HOWE’S ANALYSIS—1954 Howe devised a formula for determining whether the apical bases could accommodate the patient’s teeth. The Procedure Tooth material (TM) equals the sum of the mesiodistal width of the teeth from the first permanent molar forward. Premolar diameter (PMD) is the arch width measured at the top of the buccal cusps of the first premolars. Premolar diameter to tooth material ratio (PMD:TM) is obtained by dividing the premolar diameter by the sum of the width of the 12 teeth. Premolar basal arch width (PMBAW) is obtained by measuring, with the bowed end of the boley Gauge, the diameter of the apical base on the casts at the apical of the first premolars. The ratio of the premolar basal arch width to tooth material (PMBAW:TM) is obtained by dividing the premolar basal arch width by the sum of the width of the 12 teeth. Basal arch length (BAL) is measured at the midline from the estimated anterior limits of the apical base to a perpendicular that is tangent to the distal surface of 2nd molar. The ratio of BAL

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to tooth material (BAL:TM) is obtained by dividing the arch length by the sum of the width of the 12 teeth. Howe’s believed that the premolar, basal arch width (he called it the canine fossa diameter) should equal approximately 44% of the mesiodistal width of the 12 teeth in the maxilla if it is to be sufficiently large to accommodate all the teeth. When the ratio between basal arch width and tooth material is less than 37%. Howe’s considered that to be a basal arch deficiency necessitating extraction of premolars. If the premolar basal width is greater than the premolar coronal arch width, expansion of the premolars may be undertaken safely. Since this method was introduced, rapid palatal expansion has came into more common use and clinicians have more opportunity to alter the apical base itself. Howe’s analysis is useful in planning treatment of problems with suspected apical base deficiencies and dividing whether to 1) extract teeth 2) Widen the dental arch or 3) expand rapidly the palate. Mandibular apical base distance is more critical than that of maxillary. In the authors opinion Howe’s analysis is more logical and superior to the pont’s Index because the Howe’s analysis is applicable to each arch and has been represented as an aid to thoughtful diagnosis and planning while the Pont’s index is often used as a rigid rule and an illogical excuse for not extracting.

second permanent molars are measured and summed up. 2. Sum of maxillary 12 teeth: The mesiodistal width of all the teeth mesial to the maxillary second permanent molars are measured and summed up. 3. Sum of mandibular 6 teeth (anteriors): The mesiodistal width of all the teeth mesial to the mandibular first permanent premolars are measured and summed up. 4. Sum of maxillary 6 teeth (anterior): The mesiodistal width of all the teeth mesial to the maxillary first permanent premolars that is maxillary anteriors are measured and summed up. Determination of Overall Ratio According to Bolton’s study, the sum of mesiodistal width of the mandibular teeth anterior to second permanent molars is 91.3% of the mesiodistal width of maxillary teeth anterior to the second permanent molar. Overall Ratio =

Sum of mandibular 12

Bolton’s analysis gives significance to tooth size. According to Bolton, there exists a ratio between the mesiodistal widths of maxillary and mandibular teeth. Malocclusion occurs when there is disparity between the mesiodistal dimensions of maxillary and mandibular teeth. Bolton’s analysis helps in determining disproportion in size between maxillary and mandibular teeth. Procedure 1. Sum of mandibular 12 teeth: The mesiodistal width of all the teeth mesial to the mandibular

Sum of maxillary 12

Inferences If the ratio is less than 91.3%, then it indicates maxillary tooth material excess. Amount of maxillary excess is determined by the formula, Sum of maxillary 12 =

BOLTON’S ANALYSIS

100

Sum of mandibular 12 × by 100

91.3

If the ratio is more than 91.3%, then it indicates mandibular tooth material excess. Amount of mandibular excess is determined by the formula, Sum of mandibular 12 =

Sum of mandibular 12 × 91.3

100

Determination of Anterior Ratio According to Bolton’s study, the sum of mesiodistal widths of mandibular anteriors should be 77.2% of the mesiodistal width of maxillary anteriors. The anterior ratio is obtained by the formula,

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Anterior Ratio =

History of Orthodontics

Sum of mandibular 6 × 100 Sum of maxillary 6

analysis using the dental casts is required for this purpose. Principles of Space Analysis

Inferences If the ratio is less than 77.2%, then it indicates maxillary tooth material excess. Amount of maxillary excess is determined by the formula, Sum of maxillary 6 =

Sum of mandibular 6 × 100 77.2

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If the ratio is more than 77.2%, then it indicates mandibular tooth material excess. Amount of mandibular excess is determined by the formula, Sum of maxillary 6 =

Sum of mandibular 6 × 77.2 100

CAST ANALYSIS: SYMMETRY AND SPACE An asymmetric position of an entire arch should have been detected already in the facial/esthetic examination. An asymmetry of arch form also may be present even if the face looks asymmetric. A transparent ruled grid placed over the upper dental arch and oriented to the palatal raphe can make it easier to see a distortion of arch form. Asymmetry within dental arch, but with symmetric arch form, also can occur. It usually results either from lateral drift of incisor or from drift of posterior teeth unilaterally. The ruled grid also helps in seeing where drift of teeth has occurred. Lateral drift of incisors occurs frequently in patients with severe crowding, particularly if a primary canine was lost prematurely on one side. This often results in the permanent canine being locked out of the arch while the other canine is nearly in its normal position with all the incisors shifted laterally. Drift of posterior teeth is usually caused by early loss of a primary molar, but sometimes develops even when primary teeth were exfoliated on a normal schedule. ALIGNMENT (CROWDING), SPACE ANALYSIS It’s important to quantify the amount of crowding the arches, because treatment varies depending in the severity of crowding. Space

Since malaligned and crowded teeth usually result from lack of space, thus analysis is primarily of space within the arches. Space analysis requires a comparison between the amounts of space required to align them properly. • Analysis can be done either directly on the dental casts or by computer after appropriate digitization of the arch and tooth dimensions. • Dental cast analysis is two dimensional. • If a computer method is preferred, it is easier and more practical to use an office copying machine to obtain a 2-D usage of the occlusal view of the dental casts, then digitize from that. • A readable and surprisingly accurate image can be obtained by simply placing the casts on the center of the copying machine, avoiding the edges of its image area, where distortions often appear. • Whether done manually or computerized, the first step in space analysis is calculation of space available. This is accomplished by measuring arch perimeter from the 1st molar to the other over the contact points of posterior teeth and incisal edge of anteriors. There are two ways to accomplish this. 1. By dividing the dental arch into segments that can be measured as straight line approximations of the arch. 2. Or by contouring a piece of wire (or a curved line on computerize screen) to the line of occlusion and then straightening it out for measurement. The 1st method is preferred for manual calculation because of its greater reliability. Second step is to calculate the amount of space required for alignment of teeth. This is done by measuring the mesiodistal width of each tooth from contact point to contact point and then summing the width of the individual teeth. If the sum of the widths of the permanent teeth is greater than the amount of space available, there is an arch perimeter space deficiency and crowding would occur. If available space is larger than the space required (excess space), gaps between some teeth would be expected.

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Space analysis carried out in way is based on two important assumptions 1. Anteroposterior of the incisors is correct. (i.e. incisors are neither excessively protrusive nor retrusive. 2. The space available will not change because of growth; neither assumption can be taken for granted. It must be remembered that incisor protrusion is relatively common and that retrusion though uncommon, does occur. There is an interaction between crowding of tooth and protrusion of retrusion. • If the incisors are positioned lingually, this accentuates crowding but if the incisors protrude, the potential crowding will be at least partially alleviated. • If there is not enough room to properly align the teeth, the result can be crowding, protrusion or some contribution of the two. For this reason, information about how much the incisors protrude must be available from clinical examination to evaluate the results of space analysis. The second assumption, that space available will not change during growth is valid for adults but may not be for children. In a child with a well proportioned face, there is little or no tendency for the dentition to the displaced relative to the jaw during growth, but the teeth often shift anteriorly or posteriorly in a child with a jaw discrepancy. For this reason, space analysis is less accurate and less useful for children with skeletal problems (Class II, Class III, long and short face) than in those with good facial proportions. Even in children with well proportioned faces, the position of the permanent molars changes when primarly molars are replaced by premolars. If space analysis is done in the mixed dentition it is necessary to adjust the space available measurement to reflect the shift in molar position that can be anticipated. ARVEY PECK, SHELDON PECK—1972 It has been shown that naturally well aligned mandibular incisors possess distinctive dimensional characteristics; these teeth are significantly smaller mesiodistally and significantly larger faciallingually when compared with average population tooth dimensions.

The primary sources of facio lingual tooth size data for the incisors have been skeletal material and extracted teeth and not plaster casts. The index proposed for clinical orthodontics utilizes an MD/FL ratio. It’s constructed in the following manner.

MD crown diameter in mm × 100 FL crown diameter in mm Mandibular incisors of two groups of young female Caucasian adults from North eastern region, i.e. Boston were studied. • One group was designated as group with perfect mandibular incisors alignment, while the other was designated as the “Control population group”. The members of both sample were all within same age range (17-27 years). • For each subject in both groups, the maximum mesiodistal (MD) crown diameter and the maximum FL crown diameter were measured directly in the mouth. The mandibular central incisors of the group with perfect alignment has a mean MD/FL index of 88.4 with a SD of 4.3 • The mandibular lateral incisors of the groups with perfect alignment had a mean MD/FL index of 90.4 with a standard deviation of 4.8. • Take the lower incisor measurements in a sequence beginning with the four MD measurements, right lateral incisor to left lateral incisor followed by four FL measurements, left lateral incisor to left lateral incisor. • Male-female differences in MD/FL indices for the mandibular incisors appear to the below clinical significance. Index =

HUCKABA’S ANALYSIS • It uses both study casts and radiographs for determining the width of unerupted tooth. • It is necessary to compensate for enlargement of radiographic image. This can be done by measuring an object than can be seen both in radiograph and on the cast. A simple proportional relationship can then be established as follows; Actual width of primary molar (X1) y molars (X2) Apparent width of primary

=

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Actual width of unerupted premolar (Y1) nerupted premolar (Y2) Apparent width of un

OR Y 1 =

X1 × Y1 X2

This can be used for both arch groups.

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HIXON AND OLD FATHER METHOD—1958 They examined the dental casts and periapical radiographs of 41 children in the mixed dentition and the casts of the same children taken following the eruption of canines and premolars. Utilizing a 16 inch target film distance they found a weak correlation between the mesiodistal widths of the primary and permanent teeth. The correlation coefficient between the sum of the widths of mandibular permanent incisors and that of mandibular permanent canines and premolars measured on the casts, was similar to reported by other authors. The strongest correlation was between, on the one hand, the sum of the width of the central and lateral incisors in one quadrants, measured on the casts added to the sum of the width of the two premolars in the same quadrant, measured on radiographs and on the other, the sum of the width of the canines and premolars after their eruption. From these results the authors devised a table for prediction of mesiodistal width of unerupted canines and premolars.

combined width of the maxillary cuspid and bicuspids. c. Compute the amount of spee to left in the arch for molar adjustment by subtracting the estimated cuspid and bicuspid size from the measured space available in the arch after alignment of the incisors. Record these values for each side. From all the values now recorded, a complete assessment of the space situation in the mandible is possible. Procedure in the Maxillary Arch The procedure is similar to that for the lower arch, with two exceptions: 1) A different probability chart is used for predicting the upper cuspid and bicuspid sum. 2) Allowance must be made for overjet correction when measuring the space to be occupied by the aligned incisors. Remember width of the lower incisors is used to predict upper cuspid and bicuspid widths. It is good practice to study the radiographs when mixed dentition analysis is done in order to note absence of permanent teeth, unusual malpositions of development, or abnormalities of crown form. For example, mandibular 2nd premolars sometimes have two lingual cusps, when they are so formed, the crown is larger than might be expected from the probability chart; therefore a higher predicator value is used. Modifications

MARVIN M TANAKA, LYSTLE E JOHNSTON IN 1974 Dental casts of 506 orthodontic patients in Cleveland area were obtained from the Orthodontic Department of Case Western Reserve University School of Dentistry. To be included in the study, patients had to be of probable European ancestry and less than 20 years old. Short Method—Tanaka-Johnson A shorter but less precise method has been developed which is of merit, but does not allow for sexual dimorphism with equal accuracy. a. Add the width of the mandibular incisors and divide by two. b. To the value obtained add 10.5 mm to predict the combined widths of mandibular cuspid and bicuspids and 11.0 mm to predict the

A technique for mixed dental analysis that compensates nicely for radiographic enlargement of tooth images in periapical films is available. Its based on the assumption that the degree of magnification for a primary tooth will be the same as that for its underlying permanent successor on the same film. 1. Measure the width of the primary tooth on the X-ray film (Y1) and the width of its underlying permanent successors (X1) on the X-ray film. 2. Measure the primary tooth (Y) directly in the mouth or on the dental cast. The width of the unerupted permanent totoh (X) can then be calculated by simple mathematical proportion X : X1 = Y : Y1 or X = X1Y / Y1 X/X1 = Y/Y1 X = X1Y/ Y1

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Inaccuracy in radiographic tooth size measurements is not dentist fault. It occurs because the developing tooth are not always placed exactly at right angles to the central ray, therefore, the radiographic image of the tooth, when slightly rotated or tipped, is significantly larger than the actual size of the tooth. Ballard and Wylie 1947, conducted an investigation to evaluate the assumption that there is harmony in tooth size in any one individual that is, if the incisors are larger than average, the canines and premolars and molars are also correspondingly larger than average. They examined the casts of 441 individuals who had permanent incisors, canines, premolars and 1st molars fully erupted. They developed a predictive formula. X = 9.41 + 0.527Y and Which X = sum of mesiodistal width of canines and premolars and Y = Sum of mesiodistal width of mandibular incisors. NANCE ANALYSIS Determined the space available in the arch for unerrupted canines and premolars by measuring the mesiodistal width of primary molars and canine as dental casts, and determined the space required by measuring the mesiodistal width of the unerupted teeth on radiographs. He claimed that this assessment was accurate in most cases. He also measured total arch length from mesial surface of one permanent first molar to the other and showed that, in transition from mixed to permanent dentition, molar move mesially on average 1.7 m in lower arch and 0.9 m in upper arch. Clinical judgment: • It’s not time consuming • It requires no special equipment or radiographic projections • Although best done an dental casts, it can be done with reasonable accuracy in the mouth. • It may be used for both dental arches. Mixed Dentition Analysis have been misused in several ways: 1. They have been applied mechanically without proper regard for biologic dynamics of a critical stage is dentitional development. 2. Naive assumptions have been made (e.g. A universal 1.7 mm late mesial shaft).

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3. Many have presumed than to have an accuracy that is not present in any of the methods yet developed. None of Mixed Dentition Analysis are as precise as one might like, and all must be used with judgment and knowledge of development. Mandibular incisors have been chosen for measuring since they are erupted into the mouth early in the mixed dentition, easily measured accurately and are directly in the midst of most space management problems. Maxillary incisors are not used in any of the predictive procedures, since they show too much variability in size and their correlations with other groups of teeth are of lower predictive value. Therefore, the lower incisors are measured to predict the size of upper as well as lower posterior teeth. Procedure for Mandibular Arch—1976 1. Measure with tooth measuring gauge, the greatest mesiodistal width of each of the four mandibular incisors and record the values in mixed dentition analysis form. 2. Determine the amount of space needed for alignment of the incisors. Set the Boley gauge to a value equal to the sum of the width of the left central incisors and left lateral incisors. Place the point of the gauge at the midline of the alveolar crest between the central incisors and set the other point along the line of the dental arch on the left side. Mark on the tooth or the cast the precise point where the distal surface of the lateral incisors will be when aligned. Repeat this on the right side of the arch. If the cephalometric evaluations show the mandibular incisors to be too far labially, the Boley guage tip is placed at the midline but moved lingually a significant amount to simulate the expected uprighting of the incisors as dictated by the cephalometric evaluation. 3. Compute the amount of space available after incisor alignment. To do this, measure the distance from the point marked in the line of the arch. To the mesial surface of the first permanent molar. This distance is the space available for the cuspid and 2 bicuspids and for any necessary molar adjustment after the

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incisors have been aligned. Record data for both sides. 4. Predict the size of the combined widths of the mandibular cuspid and bicuspids.

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Long Method Experienced clinicians may choose to use the 50% prediction since it is a more precise estimate. Those who are inexperienced or without the use of cephalometrics and a precision appliance method would do well to proceed more conservatively (i.e. use 75% level of prediction). Prediction of the combined width of cuspid, first bicuspid and second bicuspid is done by use of probability charts. The tables used herein are based on size variations and relationships in teeth. North American whites and may or may not be valid for other ethnic groups. Problems A problem arises when considering the space left for molar adjustment. If this value in the chart is negative, that is, the predicted sizes of 3, 4, and 5 are greater than the space left after the alignment of the incisors, then crowding will occur in the arch even without any forward molar adjustment when the first permanent molars are in an end to end relationship (i.e. a flush terminal plane of the second primary molars, approximately 3.5 mm of space (one half a cusp width) is required to convert to a class I molars relationship. This needed 3.5 mm might be acquired, without orthodontic intervention, in any of three ways 1. 3.5 mm more late mesial shift of the mandibular first permanent molar than the maxillary. 2. At least 3.5 mm more forward growth of the mandible than the maxilla. 3. Some combination of dental adjustment and differential skeletal growth. Since we cannot yet predict accurately the amongst of differential skeletal growth that will occur, treatment planning must be based on dental adjustment factors. If differential skeletal growth occurs during this period, in the molar relationship will result and the mixed dentition analysis prediction must be altered accordingly. When there is class I molar relationships in mixed dentition, no part of

the arch perimeter need to be prevented for molar adjustment and all the space can be made available for incisors, cuspids and bicuspids. Perhaps the most severe termination of mixed dentition analyzes is their inability to reflect the position of the incisors with respect to the skeletal profile. There are a number of crude rules of thumb for determining how much arch perimeter deduction occurs for each degree or millimeter the incisor edge is changed in the cephalometric visualization of treatment. For example, one degree of tipping or 1 mm of lingual displacement of the mandibular incisal edge is said to be equal to 1 mm of arch shortening on each side. TOTAL SPACE ANALYSIS—1978 This analysis is developed by Levern Merrifield. This method has divided the lower dental arch into 3 areas. Anterior middle and posterior to analyze the space requirement in the lower arch. Measurement from study casts and cephalograms are used in this analysis Anterior Area Space Required • Measure width of mandibular incisors on the models and width of canine from radiographs. • Cephalometric correction for incisor position is calculated according to Tweeds method. FMIA is taken into consideration. The incisors are then repositioned and the difference is the actual and proposed FMIA is determined. The difference in angulations is multiplied by 0.8 mm to get difference in multi meters. • Soft tissue modification: Upper lip is measured from vermilion border of upper lip to greatest curvature of labial surface of central incisor. The total chin thickness is measured from soft tissue chin point to NB Line. • If lip thickness is greater than chin thickness the difference is determined and multiplied by 2 and added to the space required. If less no modification is necessary. • Measure Z angle of Merrifield and add the cephalometric correction to it. If corrected angle is greater than 80°, the mandibular incisor angulations is modified is necessary.

History of Model Analysis

If the correlate angle is less than 75° additional uprighting of mandibular incisor is necessary. Space Available Measure space availability by using brass wire from mesiobuccal line angle of first primary molar of one side to another.

b. Estimated increase: The increase is 3 mm per year, i.e. 1.5 on either side until 14 years of age in girls and 16 years in boys. Total space deficit: This is arrived by comparing the space required and space available in anterior, middle and posterior. Thus we can know where the discrepancy is present. WYLIE

Middle Area

Commenting on Model Analysis

Space Required

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• Measure mesiodistal width of first premolar as the cast and measure width of the unerupted premolar from the radiographs. • Curve of occlusion: A flat object is placed on the occlusal surface of mandibular teeth containing the incisors and first molar. The deepest position between the flat surface is measured and occlusal surface of primary molars was measured on both side. Depth on right side + depth of left side + 0.5 mm 2 mm

Space Available Using brass wire measure from mesiobuccal line angle of first primary molar to the distal buccal line angle of first permanent molar on either side.

In the year 1959, Commenting on model analysis methods point out “first of all, it is next to impossible to measure bone dimension from even the best plaster cast.”Teeth, yes with great accuracy. But no one can arrive a reliable ratio without measuring the both components accurately. As a matter of fact, only the procedure of Howe’s Pretends to measure anything but tooth-size and between teeth. Second, one over simplifies the problem when he Presumes that crowding can be analyzed completely. When he knows the size of teeth basal bone. But admits that we cannot ignore the abundant Empirical evidence that such procedures work, because through trial and error, we have discovered the dimensions which we should accept as timing factor. KESLING MODEL ANALYSIS

Posterior Area Space Required a. Mesiodistal width of II and III molars is obtained from radiographs as they might be unerupted. If not visible Wheelers method is used for calculation X = Y-X1/Y1 X = Estimated width of 3rd molar Y = Actual size if premolar 1 mandibular molar X’ = Wheelers value for 3 molars. Y’ = Wheelers value for 1 molars.

In the year 1945, he reported his analysis. Kesling gave a method of analysis, which was so-called “diagnostic setup”. Aim of this analysis is to determine the needs of reducing tooth material. MARTINEK ANALYSIS Comparative Analysis of Howes, Rees, Kesling and Strayer Martinek, in the year 1957, presented an interesting paper on comparing the analysis of Howes, Rees, Kesling, Strayer on five treated cases.

Space Available Amount of space available consists of space presently available on casts and estimated increase. a. Space presently available; obtained by measuring the distance on occlusal plane to distal surface of I molar to anterior border of ramus on lateral cephalogram

SUWANNEE LUPPANAPORNLARP In the year 1993, Suwannee luppanapornlarp, studied the long-term comparative effects of premolar extraction in clear-cut extraction and non extraction class-2 patients. He concluded that premolar extraction produced a significantly greater reduction in hard and soft tissue protrusion

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both treatments produced the mandibular mesial displacement—extraction significantly more than non-extraction. However, at recall the two groups did not differ with respect to signs and symptoms of dysfunction. 3D MODEL ANALYSIS

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In the current age, where today’s technological barrier is tomorrow’s technological breakthrough, we are continuously reinventing industries, manufacturing and design practices and finding innovative applications of new technological

breakthroughs for tried and true practices. The first time 3D modeling technologies were applied to the dental industry was in 1987 by Dr Mormann. The 3D modeling technology, at this point and time, allowed Dr Mormann to revolutionize the reconstructive dental industry. Over the years, as 3D modeling technologies improved, the application became ever more revolutionary. Here is a partial list of currently available treatments designed with the aid of 3D modeling software: Bending ART system Invisalign® treatment, Suresmile process Orthocad, E-models, etc.

History of Cephalometrics

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History of Cephalometrics

• History Prior to the Advent of Radiography – Classifying Physiques – Measurements and Proportions – Renaissance to the Twentieth Century - Leonardo da Vinci - Albrecht Durer - Spigel - Pieter Camper - Deschamps - Johann Friedrich Blumenbach - Anders Retzius - Thomas Huxley

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14

- Broca - Paul Topinard - Ihering

• Other Important Contributions – Allan G Brodie – Thompson and Brodie – Margolis • Cephalometric Radiography – Wylie – Wilhelm Conrad Roentgen – Wilhem Koening and Dr Otto • Cephalometric Analysis • Evolution of Cephalometrics Walkhoff • Patient Orientation – Van Loon – AJPacini and Carrera • X-ray Source Position – Atkinson • Film Position and Enlargement – Simpson • Posteroanterior (Frontal) – Dewey and Riesner Cephalometry – Down’s Analysis • Holly B Broadbent’s – Steiner Analysis Contribution – Tweed’s Triangle – Paul Simon – Wit’s Appraisal – Charles Bingham Bolton

Ever since God created man in his image, man has been trying to change man into his image. Attempts to change facial appearance are recounted throughout recorded history. The question of what is a normal face, as that of what constitutes beauty, will probably never be answered in a free society. Orthodontists, in their attempts to change facio-orodental deviations from accepted norms, have adopted cephalometric measurement, a method long employed in physical anthropology. With the introduction of roentgenography, it was inevitable that this procedure should be employed as a medium for the purpose of roentgenographic cephalometrics. Cephalometric radiography was introduced into orthodontics during the 1930s.

Cephalometry had its beginning in craniometry. Craniometry is defined in the Edinburgh encyclopedia of 1813 as “the art of measuring skulls of animals so as to discover their specific differences”. For many years, anatomists and anthropologists were confined to measuring craniofacial dimensions using the skull of dead individuals. Although precise measurements were possible, craniometry has the disadvantage for growth studies. Cephalometry is concerned with measuring the head inclusive of soft tissues, be it living or dead. However, this procedure had its limitations owing to the inaccuracies that resulted from having to measure the skulls through varying thickness of soft tissues.

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With the discovery of X-rays by Roentgen in 1895, radiographic cephalometry came into being. It was defined as the measurement of head from bony and soft tissue landmarks on the radiographic image (Krogman and Sassouni 1957). This approach combines the advantages of craniometry and anthropometry. The disadvantage is that it produces two-dimensional image of a three-dimensional structure. HISTORY PRIOR TO THE ADVENT OF RADIOGRAPHY

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Classifying Physiques History prior to the advent of radiography should begin with the mention of attempt of the scientists to classify the human physiques. In 500 BC, the Greek physician and Father of medicine, Hippocrates, designated two physical types — habitus phithicus with a long thin body subject to tuberculosis, and habitus applecticus— a short thick individual susceptible to vascular diseases and apoplexy. The search was continued by Aristotle, Galen (200 AD) and Rostan (1828). Rostan was the first to include muscle mass as a component of physique. Viola’s (1909) morphological index recognizes three morphological types. Kretschmer (1921) adhered to the three Greek terms: the pyknic (compact), aesthetic (without strength), and athletic. Kretshmer also included dysplastic physique which was taken up by Sheldon again in 1940. The long historic thread extended into the twentieth century when Sheldon introduced his method of somatotyping, based on three components of physiques, each rated on a seven point scale and expressed as a three digit number called somatotype. It also included a rating of dysplasia in the five regions of the body. “Dysplasia is literally bad shape or form. In somatotyping, it refers to disharmony or uneven distribution of a component or components in different parts of the body,” according to Carter and Heath. Moreover their definition of a somatotype quantifies relative fatness or endomorphy, relative musculoskeletal robustness or mesomorphy and relative linearity or ectomorphy. The somatotype then stands as a “measuring of overall appraisal of body shape and composition, an anthropological identification tag and a useful description of human physique.”

Sheldon’s temperamental components, viscerotonia, somatotonia, and cerebrotonia, convey behavioral traits commonly associated with physique. With a seven-point scale for each somatotype component, there is a wide distribution in the dense midrange around the 4-4-4 type; a close relation between somatotype and temperament becomes tenuous. Nonetheless, common knowledge suffices to recognize dominant behavioral trait in many instances, and that information can be revealing about the people in general. It may also give some clues relating to the orthodontic treatment by providing an insight to the character of the patients—their expectations concerning the treatment’s contribution to their well being, even their understanding and willingness to accept the discipline of cooperation needed for successful conclusion of therapy. Measurements and Proportions Early History—the Canons Portrayal of human form demands not only artistic talent and technical ability but also disciplined and consistent style. To ensure these stipulations when images of royalty and deity were commissioned and executed, the ancient Egyptians developed an intricate quantitative system that defined the proportions of the human body. It became known as the Canon. The theory of proportions according to Panofsky is a system of establishing the mathematical relations between the various members of the living creature, in particular of the human being. The mathematical relation can be expressed by the division of a whole as well as by the multiplication of the unit; the effort to determine them could be guided by the desire for beauty as well as interest in the norms, or finally by the need for establishing a convention. Initially the canons were enclosed in a grid system of equalized squares with 18 horizontal lines, line 18 drawn through hairline. Later it was included in a grid system of 22 horizontal lines, line 21 drawn through the upper eyelid. After the outline of the human figure, was drafted on papyrus leaves the iconographic norms or canon, served to insert the figure into a network of equal squares. The image could be transferred to any required size by first drawing a coordinate system to proper size; into this

History of Cephalometrics

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system the image can then be drawn readily and accurately for displaying in a tomb or on a wall. This procedure is still universally used to enlarge or reduce any kind of illustration. Indian econometric studied extensively by Ruelius, was transmitted through sanskrit literature and extensively reviewed in Indian texts of architecture. The proportional canons of that system were already detailed in older sources and did not materially change with time. Face height was used as the module of both the Sariputra and Alekhyalakshana proportional system, which closely reflected the natural relation of the parts of the body with each other. The Sariputra system, dated 1200 AD are known for the sculptures honoring the God Buddha. Renaissance to the Twentieth Century Fifteenth century saw the advent of specific measurements being made to compare the features of different skulls and heads. Leonardo da vinci (1452–1519 AD) was probably one of the earliest people of note to apply the theory of head measurement to good effect in practice. He used a variety of lines related to specific structures in the head to assist in his study of the human form. His drawings included a study of facial proportions in natural head position. According to the notes, the profile was divided into seven parts by eight horizontal lines. Subdivision is made with vertical lines. In his study of horse and horse men, he used a scheme of facial measurement within a grid system with five horizontal and six vertical lines and the subject in natural head position. The joining of the lower lip and the chin and the tip of the jaw and the upper tip of the ear with the temple forms a perfect square; and each face is half a head. Albrecht Durer (1471–1528 AC) was a brilliant, unusually productive and an exuberant artist of great virtuosity. He published a treatise in 1528 on cranial measurements which comprised “Vier Bucher von menschlicher Proportion” dealing with the proper proportion of human form in the first two books, the proportions according to mathematical rules in third book, the human figure in motion in the fourth book. Durer’s four books mark a climax, which the theory of proportions had never reached before or was to reach ever after.

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Using strictly geometrical methods, he provided a proportionate analysis of the leptoprosopic (long) face and euryprosopic (broad) face in coordinate system, where the horizontal and the vertical lines were drawn through the same landmarks or facial features. His drawings attest continuous efforts to define variations in the facial morphology. One of this is significant as the key to cephalometric analysis. In the difference between the retroclined and the proclined, facial profile is shown by a change of angle between the vertical and the horizontal axes of a rectangular coordinate system to characterize the facial configuration of each subject. Sixteenth century saw the first truly scientific attempt in cranial measurement and the introduction by Spigel (1578–1625 AD) of the “lineae cephalometricae”. Spigel’s linear cephalometricae consisted of four lines: the facial, occipital, frontal and sincipital lines. He described these lines as follows: • Facial: from the most inferior point of the chin to the most superior point on the forehead. • Occipital: from the crown of the head to the atlas. • Frontal: from one temple to the other. • Sincipital: from the lowest part of the ear, in the region of the mastoid process, to the highest part of the sinciput, sinciput being the anterior part of the head or skull from forehead to the crown. According to him, in a well proportioned skull, these lines should all be equal. The Dutchman Pieter Camper (1722–1789 AD) was credited with the introduction of facial angle and for famous publication “Dissertation sur les varietes naturelles de la physionomie” which appeared posthumously in 1791. The key to his methodology was to orient crania in space, horizontal from the middle of the porus acusticus to a point below the nose. Camper’s horizontal became the reference line for the angular measurements used to characterize evolutionary trends in studies of facial morphology and aging. The facial angle as he described, was formed by the intersection of a facial line and a horizontal plane. The facial line was a line tangential to the most prominent part of the frontal bone and to the slight convexity anterior to the upper teeth.

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The horizontal plane passes through the lower part of the nasal aperture, backwards along the line of the zygomatic arch and through the center of the external auditory meatus. Camper’s facial angle was readily accepted as standard measurement in craniology. The terms prognathic and orthognathic introduced by Retzius are tied to Camper’s illustrations of facial form in man and primates. As a result, the angle between a horizontal line and the line from nasion to prosthion became the time-honored anthropological method to determine the facial type. The term prognathism refers to the prominence of the face or jaws, relative to the forehead, and a straight facial profile became labeled as orthognathous. The drawbacks of Camper’s facial angle were: • It ignores the contribution made by the lower jaw to facial forms. • He did not adhere strictly to his location of posterior reference point for the horizontal plane. • The direct comparison of skull of different ages was not possible because the locating point might alter in position relevant to other bony structures with advancing age. Shortly after this, Deschamps (1740–1824 AD) introduced the cephalic triangle made up of facial, occipital, and coronal angles. The facial angle was the lesser angle formed by the intersection of a horizontal line that passes from the external auditory meatus to the base of the nose, which crossed a profile line. This is similar to Camper’s facial angle. Fortunately, the use of external auditory meatus as a reference point enabled a rough comparison to be made between different skulls. In the same period as Camper, there was a French man, Daubenton who was very concerned with the relative position of the foramen magnum in man and lower animals. He made use of new angles, including the occipital angle to make measurements. Although his measurements were not very reliable, a similar angle was later used by another craniologist, Pierre Broca. Daubenton’s occipital angle is formed by two lines, the first line passes along the level of opening of the foramen magnum, from the initial edge of the foramen along the surface of the occipital condyles and anteriorly for short

distance. The second line passes from the posterior margin of the foramen magnum to the tip of the nasal spine. Broca’s occipital angle was formed by two different lines giving alternative angles, originating from the posterior and anterior margins of the foramen magnum and passing anteriorly through the junction of frontal and nasal bones. The magnitude of occipital angle decreases as the habitual posture of the animal tend more towards upright. An antagonist of Camper, Johann Friedrich Blumenbach (1752–1840 AD) rejected the method of lines and angles as a test of national characteristics and proposed a minute survey of the skull particularly the frontal and maxillary bones. In 1795, he described a method of positioning the cranium which has to be measured in a standard reproducible manner. His method was simple, consisting of resting the skull on its base and looking down vertically upon its vault. The points to be noted were, the projection of the maxilla anterior to the frontal arch, the direction, of the jaws and cheek bones (outward, forward, etc.) and the proportional breadth or narrowness of the head. Anders Retzius (1796–1860 AD) correlated the two schemes, i.e. of Camper and Blumenbach, thereby providing a basis for the methods of craniology used today. He is also credited with the introduction of cephalic index, the ratio of breadth to length of the skull expressed as a percentage. Nineteenth century produced three great men in the history of craniology: Huxley, Broca and Topinard. Thomas Huxley (1825–1895 AD) wrote in 1876, “the so-called facial angle, in the fact, does not simply express the development of jaws in relation to face, but is the product of two factors, facial and cranial, which vary independently. The face remaining the same, prognathism may be indefinitely increased or diminished, by rotation of the frontal region of the skull, backward or forward, upon the anterior end of the basicranial axes”. He also introduced two new angles, the sphenomaxillary and spheno- ethmoidal angles. He preferred the spheno- maxillary angle to Camper’s angle when comparing the degree of prognathism in different skulls. This angle is formed by the two lines drawn from basion and prosthion to prosphenion. The other angle,

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History of Cephalometrics

sphenoethmoidal tends to be less than 180° in man. Broca (1824–1880 AD) who is the founder of the Paris society of anthropology believed that the great variability of the cranial form constituted a principal difficulty for the craniologist. He was the first craniologist to institute a precise and accurate technique which could be used to compare crania so that it was made possible to discriminate between the variation in racial types among human skulls. He introduced a base line “plan alveolocondylien” which passes through the alveolar point and tangential to the inferior surfaces of the two occipital condyles. He also developed a craniostat, mainly constructed of wood for positioning the skull. It was generally accepted at this time that the angles were best determined on projected drawings of the skull. Broca devised a simple method to trace the outline of the skull on to a piece of paper by fixing the skull in the craniostat and positioning a drawing board with paper attached to it parallel to the midsagittal plane and a pencil held in a frame perpendicular to the paper. The resultant tracing was equivalent to a tracing of the peripheral, as depicted on a lateral skull radiograph. Paul Topinard (1830–1912 AD) used a similar craniostat with some additional modifications. Topinard wrote in 1890 “the craniometer substitutes the mathematical data for the uncertain data founded on judgment and opinion. Moreover it studies the skeleton of the ensemble, the cranium and the face separately and each of the plates as well”. During nineteenth century, the need for standardization of methods used in craniometry became an important issue and since then, many bodies have met to better define those points and planes in use. The most important meeting as far as the dental profession is concerned was held in Frankfurt-am-Main in August 1882. This was the 13th General congress of the german anthropological society and it is to this congress that the Frankfurt horizontal plane owes its name. Earlier in 1859, a horizontal plane following the zygomatic arches was suggested by a Russian craniologist, Von Baer. Later, the plane was defined more precisely as line drawn from the

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center of each auditory meatus to the lower point on the inferior margin of each orbit by Von Ihering (1850–1930). The Frankfurt agreement modified Von Ihering’s definition such that the plane passes through the upper border of the bony meatus vertically above their centers. However, the reproducibility of this plane on an intact skull is less than Broca’s condyloalveolar plane. Subsequent to the agreement, the definition of the horizontal plane has been altered so that it is now taken as passing through the right and left porion and left orbitale. Thereby, reducing the problems incurred by asymmetrical skulls. CEPHALOMETRIC RADIOGRAPHY In 1895, Professor Wilhelm Conrad Roentgen made a remarkable contribution in the field of science with the discovery of x-rays. On December 28, 1895, he submitted a paper “On a new kind of rays, A Preliminary Communication” to the Wurzburg Physical Medical Society for publication in its journal. Professor Wilhem Koening and Dr Otto Walkhoff simultaneously made the first dental radiograph in 1896. It was clear that the use of X-rays provided the means of obtaining a different perspective on the arrangement and relation of bones, thus expanding the horizons of craniometry and cephalometry. The evolution of cephalometry in the twentieth century is universally linked to Edward Hartlay Angle’s publication of his classification of malocclusion. But the dogmatic inferences of the new school were criticized for failing to include differential diagnosis of facial profile in patients with class III and class II malocclusion. Van Loon was probably the first to introduce cephalometry to orthodontics, when he applied anthropometric procedures in analyzing facial growth by making plaster casts of face into which he inserted oriented casts of the dentition. Hellman used cephalometric techniques and described their value beginning with 1920s. The first X-ray picture of skull in the standard lateral view was taken by AJ Pacini and Carrera in 1922. Pacini received a research award from the American Roentgen Ray Society for a thesis entitled “Roentgen ray anthropometry of the skull”. Pacini introduced a teleroentgenographic

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technique for standardized lateral head radiography and thereby opened a way, which proved to become a tremendous advance in cephalometry, as well as in measuring the growth and development of face. His method, which was rather primitive, involved a large fixed distance from the X-ray source to the cassette. The head of the subject, placed adjacent to a standard holding the cassette, was immobilized with a gauze bandage wrapped around both the face and the cassette after the patient’s midsagittal plane was carefully oriented parallel to the cassette. He identified the following anthropometric landmarks on the roentgenogram: gonion, pogonion, nasion, and anterior nasal spine. He also located the center of the sella turcica and the external auditory meatus. He measured the gonion angle and the degree of maxillary protrusion. Atkinson in 1922 advocated the use of roentgenograms in locating the ‘key ridge’ and the soft tissue relations to the face and jaws. In 1923 McCowen reported on profile roentgenograms that he used for orthodontic purposes to visualize the relationship between the hard and soft tissues and to note the changes in profile which occur during treatment. Simpson presented a method for obtaining profile roentgenograms in 1923 before American Society of Orthodontists. In 1927, Ralph Waldron of Newark, NJ made mention of measuring the gonion angle from a roentgenogram taken at 90o to the facial profile. Waldron was the first to construct a cephalometer, which differed little from those used today. In 1928, Dewey and Riesner published an article, “A Radiographic study of facial deformity”. Dewey and Riesner immobilized the patients head in a head clamp and placed the cassette against the patient’s face. They took profile roentgenograms by aligning the eye to ear plane by a right angle leveling technique. They used a target distance of three feet. In 1931, the methodology of cephalometric radiography came into full function when B Holly Broadbent in USA and H Hofrath in Germany simultaneously published methods to obtain standardized head radiographs in the angle orthodontist (A new X-ray technique and its application to orthodontia) and in Fortschritte der Orthodontie, respectively.

This development enabled orthodontists to capture the field of cephalometry from the anatomists and anthropologists who had monopolized craniometric studies, particularly in nineteenth century. HOLLY B BROADBENT’S CONTRIBUTION Broadbent’s interest in craniofacial growth began with his orthodontic education under E H Angle in 1920. He continued to pursue that interest along with his orthodontic practice, working with a leading anatomist J Wingate Todd. The idea of diagnosing dental deformities by means of planes and angles was first proposed in 1922 by Paul Simon of Germany in his book, “Fundamental principles of a systematic diagnosis of dental anomalies”. Although his “Law of the canines” was later disproved by Broadbent, his theories stimulated the latter to apply the principles of craniometry to living subjects. The uncertainty of locating landmarks in the skull of the living child by approaching through skin and soft tissues led him to search for a means of recording craniometric landmarks on the living child accurately as done with a craniostat in measuring the dead skull. During 1920’s, Broadbent refined the craniostat into craniometer by the addition of metric scales. This proved to be the first step in the evolution of craniostat into a radiographic cephalostat. It did not take him much longer to convert the direct measuring instrument into a radiographic craniometer. Meanwhile, the course of Broadbent’s orthodontic practice corrected the malocclusion of Charles Bingham Bolton, son of Chester and Francis P Bolton. His discussions of facial growth with Congress woman, Bolton led to the addition of Bolton study of facial growth to the long list of Bolton philanthropies. As Charles grew to adulthood, this study became a major personal as well as financial commitment. Cephalometrics was neither developed as a technique looking for an application nor was it developed as a diagnostic tool. Broadbent’s single goal was the study of craniofacial growth. The Broadbent’s technique for cephalometric radiography was one of the tools which he developed for the implementation of that study.

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History of Cephalometrics

The technique and apparatus perfected for the Bolton fund study of the normal developmental growth of the face, eliminated practically all of the technical difficulties encountered in previous methods of recording dentofacial changes, and proved to be a convenient as well as scientific method of measuring orthodontic procedures. According to Broadbent, the patient’s head was centered in the cephalostat with the superior borders of the external auditory meatus resting on the upper parts the two ear rods. The lowest point on the inferior bony border of the left orbit, indicated by the orbital marker, was at the level of the upper parts of the ear rods. The nose clamp was fixed at the root of the nose to support the upper part of the face. The focus film distance was set at five feet (152.4 cm) and the subject film distance could be measured to calculate image magnification. With the two X-ray tubes at right angles to each other in the same horizontal plane, two images (lateral and posteroanterior) could be simultaneously produced. Germany’s Hofrath’s technique differed from Broadbent’s technique in this way of the central ray was not fixed in relation to the head and no plan was suggested for super-positioning subsequent X-rays. OTHER IMPORTANT CONTRIBUTIONS In 1937, using serial records of twins; Broadbent showed how growth or its lack was the greatest limiting factor in clinical success. In 1943, he stipulated that, eruption of the third molars had no ill effect on the denture, particularly the lower incisors. • In 1938, Allan G Brodie at the University of Illinois presented a cephalometric appraisal of orthodontic results: 1. The use of elastic causes a disturbance in the Bolton plane-occlusal plane angle; 2. Axial inclinations of orthodonticallymoved teeth tend to return to their original inclinations. 3. Bone changes during treatment are restricted to the alveolar process. • Brodie, in a landmark study (1941) used for his PhD in anatomy, corroborated Broadbent’s contention that the growth pattern of the normal child’s face develops in an orderly fashion downward and forward

and the pattern once attained at an early age, did not change. • Thompson and Brodie (1942) in a report on the rest position of the mandible, concluded that: 1. Morphogenetic pattern of the head was established ata early age and did not change, 2. Presence or absence of teeth has little bearing on the rest position of the mandible and 3. Vertical facial proportions are constant throughout life. Margolis (1943) wrote on the relationship between the inclination of the lower incisor and the incisor-mandibular plane angle and was the first to corroborate Tweed’s clinical observation that, in normal occlusions, the lower incisors are 90° to the mandibular basal bone. In 1947, Wylie produced a method of assessing anteroposterior dysplasias and that same year, Margolis contributed his maxillofacial triangle. CEPHALOMETRIC ANALYSIS The major use of radiographic cephalometry is in characterizing the patient’s dental and skeletal relationships. This led to the development of a number of cephalometric analyzes to compare a patient to his or her peers, using population standards. William B Downs (Fig. 14.1 ) in 1948

Fig. 14.1: William B Downs (1899–1996)

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Fig. 14.2: Herbert I Margolis (1900–1984)

developed the first cephalometric analysis. Its significance was that, it presented an objective method of portraying many factors underlying malocclusion and there could be a variety of causes of malocclusion exclusive to teeth. This was followed by another analyzes by Cecil C Steiner (1953), CH Tweed (1953) , RM Ricketts (1958), V Sassouni (1969), HD Enlow (1969), JR Jaraback (1970), Alex Jacobson (1975), etc. EVOLUTION OF CEPHALOMETRICS The thoroughness of Broadbent’s approach to the design of the cephalometric method is evident from the fact that the basic technique has survived almost unchanged for over seventy years. In about two decades time, the instrumentation had evolved to a form more suitable for the individual practitioner through the pioneering efforts of Margolis (Fig. 14.2), Higley and others. PATIENT ORIENTATION The ears were established as the basis for orientation and fixation in the beam axis. Frankfurt plane was adopted for horizontal orientation with nasion for stabilization. The Frankfort horizontal plane (FHP) was chosen because this was approximate the natural head position (NHP). But the FHP also had its drawbacks and those were: 1. Some individuals show a variation of their FHP to the true horizontal to an extent of ± 10°.

2. The landmarks to locate the FH plane, orbitale and porion, especially the latter, are difficult to identify on a cephalogram. An alternative to overcome this problem was to use a functionally derived NHP. According to Morrees and Kean, it was obtained by asking the subject to look at the image of their eyes in the mirror located at eye level. A frame of reference was originally intended as a reliable procedure for orienting facial profiles so that, same orientation could be established on different occasion by different investigators. Although the functionally derived NHP was more accurate, its reproducibility was less than FHP (anatomic approximation of NHP). Lateral and posteroanterior views perpendicular to each other in the horizontal plane were specified for three-dimensional analyses. Bjork’s studies of facial prognathism illustrated the unreliability of intracranial reference lines in cephalograms. Kroagman and Sassouni (1957) conducted an exhaustive survey of roentgenographic cephalometry in which the FHP (Frankfort horizontal plane) coincided with the physiologic or true horizontal. Sassouni made an attempt to standardize the orientation of cephalograms by means of an optical plane advocated in 1862 by Broca, who stated that “when a man is standing and when his visual axis is horizontal, his head is in natural position”. X-RAY SOURCE POSITION The X-ray source is positioned five feet (152.4 cm) from the subject’s midsagittal plane. A change to 150 cm has been adopted by some as a conveniently round metric number, but the difference is negligible. A major improvement in lateral cephalostats is, the capability of taking lateral and posteroanterior views with a single X-ray source instead of two. FILM POSITION AND ENLARGEMENT The other significant change from the original technique is adjustability of film position. The original cephalostat was based on the design of the anthropometric craniometer and cassettes were attached to these mechanisms. The disadvantage

History of Cephalometrics

of this very efficient mechanical design is that it makes cassette position and resultant enlargement depended on head size. Evaluation of serial changes by direct superimposition is made unreliable by this variable enlargement. The relative immunity of angular measurements to enlargement distortions led many researchers to opt for angular over linear values whenever possible. Also newer instruments have been developed that can over come this drawback of variable enlargement by providing independent adjustments for head holding mechanisms and cassette.

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POSTEROANTERIOR (FRONTAL) CEPHALOMETRY Since the introduction of a standardized method for obtaining skull radiographs, cephalometrics has become one of the major diagnostic tools in orthodontics. The posteroanterior cephalogram contains diagnostic information not readily available from other sources. This information allows the practitioner to evaluate the width and angulation of the dental arches in relation to their osseous bases in the transverse plane; evaluate the width and transverse positions of the maxilla and mandible, evaluate the relative vertical dimensions of bilateral osseous and dental structures; assess nasal cavity width, and analyze vertical and/or transverse facial asymmetries. Malocclusions and dentofacial deformities constitute three-dimensional conditions or pathologies. Although all orthodontic patients deserve an equally comprehensive three dimensional diagnostic examinations, assessment of posteroanterior cephalometric views are of particular importance in cases of: 1. Dentoalveolar and facial asymmetries 2. Dental and skeletal cross bites 3. Functional mandibular displacements. The same equipment that is used for the lateral cephalometric projections is utilized. The initial unit described by Broadbent consisted of a set up in which two X-ray sources with two cassettes were simultaneously used, so that lateral and frontal cephalograms were taken at the same time. Although precise-threedimensional evaluations are possible using this technique, it has now been almost abandoned

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since it requires rather large equipment with two X-ray sources. Modern equipment uses one X-ray source. Therefore, following lateral cephalometric registration, the patient must be repositioned if a posteroanterior cephalogram has to be produced. A head holder or cephalostat that can be rotated 90° is used, so that the central X-ray beam penetrates the skull of the patient in a posteroanterior direction and bisects the transmeatal axis perpendicularly. Maintaining the identical horizontal orientation from lateral to the posteroanterior projection is critical when comparative measurements are made on each other (Moyers et al, 1988). In using natural head position for posteroanterior cephalometric registrations, some practical problems are encountered. The patient’s head is facing the cassette; which makes it difficult for the patient to look into a mirror to register natural head position (Solow and Tallgren, 1977). Furthermore, space problems make it impossible to place a nose piece in front of nasion to establish support in a vertical plane. For better evaluation of patients with craniofacial anomalies that require special attention to the upper face, the patient head should be positioned with the tip of the nose and forehead lightly touching the cassette holder. (Chierci, 1981) In cases of suspected significant mandibular displacement, the posteroanterior cephalogram should be taken with the mouth of the patient slightly open in order to differentiate between functional mandibular displacements and dentoskeletal facial asymmetry (Faber, 1985). As far as exposure conditions and considerations are considered, more exposure is needed for posteroanterior cephalograms than lateral views (Enlow, 1982). Cephalometric radiography, which came into widespread use after the Second World War, enabled orthodontist to measure the changes in tooth and jaw positions produced by growth and treatment. Among other findings, these radiographs revealed that many class II and Class III malocclusions resulted from faulty jaw relationships, not just malposed teeth. By the use of cephalometrics, it was also possible to see that jaw growth could be altered by orthodontic treatment.

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According to Salzmann, cephalometric radiograph can show following features; 1. Show dimensional relationship of the craniofacial components. 2. Reveal manifestations of growth and developmental abnormalities. 3. Helps in treatment planning. 4. Helps in diagnosing the patient, especially of skeletal origin. 5. Helps in evaluating the dentofacial growth changes during and after the orthodontic treatment. The goal of cephalometric analysis is to estimate the relationship, in all three planes that is in anteroposterior, vertical and transverse relationship of the jaws to the cranial base and to other, the relationship of the teeth to their supporting bone, and the effect of the teeth on the profile. In the 16th century, artists Durer and Da Vinci sketched a series of human faces with straight lines joining homologous anatomic structures. Variations in these lines highlighted the structural difference among the faces. These facial proportions were basically an artist’s attempt, with beauty and harmony as the guiding principles, to quantify the basic structures of the human face. Much later, the anthropologists invented an instrument—the craniostat, which helped in orienting dry skulls and facilitating standardized measurement. This improved the art of comparisons as the instrument improved reproducibility but this also did not allow the study of skulls of living humans. The discovery of the X-rays in 1895 by Sir William Conrad Roentgen, proved to be a boon in this direction. Orthodontic diagnosis and treatment planning for growth children must involve growth prediction. The pubertal growth spurt is considered to be an advantageous period for certain types of orthodontic treatment and should be taken into account together with orthodontic treatment planning. Because of the wide individual variation in the timing of the pubertal growth spurt, chronological age is an unreliable guide for assessment of children development status. Other parameters such as, growth velocity, secondary sex changes, dental development and

skeletal ossification, have proven to be more accurate. The standard method to evaluate skeletal maturity has been the use of hand-wrist radiographs, matching the overall pattern of the subject’s maturation to a set of reference patterns, available in an atlas. Skeletal maturation is generally determined by evaluating either the stage of ossification of bones of the hand and wrist, due to the large number of different types of bones available in these areas, or the ossification onset of the ulnar sesamoid. However, to avoid taking additional radiographs, the cervical vertebrae, as seen on routine lateral cephalograms, have been used to determine the skeletal maturity. It is well known that the lateral view of cervical vertebral bodies change with growth. In 1972, Lamparski stated that the cervical vertebrae were as statistically and clinically reliable in assessing skeletal age as the hand-wrist technique. In recent years, evaluation of cervical vertebrae has been increasingly used to determine skeletal maturation. Several authors have reported a high correlation between cervical vertebrae maturation and skeletal maturation of the hand-wrist. It has been found that cervical vertebrae could offer an alternative method for assessing maturity without the need of handwrist radiographs. However, cervical vertebrae were used to evaluate growth in a subjective manner because the method consisted of a qualitative comparison between the patient radiographs and the images contained in the atlas. Mito et al (2002) established a new method for objectively evaluating skeletal maturation on cephalometric radiographs. A regression formula was determined to obtain cervical vertebral bone age based on ratios of measurements of the third and fourth cervical vertebral bodies. However, the population used to derive the formula consisted of Japanese girls only. The study of facial form as revealed in the analysis of lateral skull radiographs. In addition to clinical examination, analysis of a lateral cephalogram permits a more detailed evaluation of facial and dentoskeletal structures to aid diagnosis and treatment planning, especially in cases with a skeletal discrepancy. Also provides

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baseline measurements to monitor the effects of growth and development.

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Lucien De Coster: Lucien De Coster of Belgium in the year 1939, was the first to publish an analysis based on proportional relationships in the face conforming to the principles used in antiquity. Wits analysis: The Wits analysis (1967) gets its name from the University of Witwatersrand in South Africa; it was brought stateside by Alexander Jackobson of the University of Alabama. Rejecting dependence on the ANB angle, Jacobson relates A and B linearly by verticals from the occlusal plane. Like the Harvold analysis, the Wits analysis concentrates on the skeletal discrepancy between the jaws. It determines the magnitude of the jaw discrepancy by relying on the linear difference between points A, B and the occlusal plane. The wits take into account, the horizontal and vertical relationship of the jaws, but its weakness is that it is influenced by the dentition and therefore skews the analysis from indicating the true skeletal discrepancies between the jaws.

Fig. 14.3: Tweed’s triangle

Tweed’s Triangle Tweed in the year 1954 based on the hypothesis that, in the normal occlusion, the mandibular incisors are upright over the basal bone, constructed a triangle formed by the lower central incisor, mandibular plane, and Frankfort horizontal plane. The Tweed’s triangle (Fig. 14.3) makes use of three planes that form a diagnostic triangle called Tweed’s triangle. Following are the planes of Tweed’s triangle: 1. Frankfort mandibular plane angle (FMPA) 2. Incisor mandibular plane angle (IMPA) 3. Frankfort-mandibular incisor plane angle (FMIA)

Fig. 14.4: Richard A Riedel (1922–1994)

studies at the University of Washington of longrange treatment stability have left us an unsurpassed legacy. The ANB angle is defined as the mutual relationship, in sagittal plane, of the maxillary and mandibular bases.

ANB Angle

STEINER’S ANALYSIS: CECIL C STEINER (1896–1989)

Richard A Riedel (1922–1994) (Fig. 14.4), introduced ANB angle before completing his Master’s degree at Northwestern University in United States of America. Nowadays this is most widely used diagnostic cephalometric angle. The ANB angle represents the anteroposterior relationship of the maxilla with the mandible. In addition to his cephalometric research Riedel’s

Cecil C Steiner was Angle’s second student at the Pasadena school. He was initially rebuffed because he did not know who Charles Darwin was. Later with mother Angle’s encouragement, he not only got the admission but also carved his name in the orthodontics. The Steiner analysis, published in 1953, offered specific guides for the use of cephalometric measurements

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in treatment planning, based on what compromised incisor positions would be necessary to achieve normal occlusion when the ANB angle was not ideal. It I also incorporated arch length and other considerations, such as the profile, enabling even the neophyte orthodontist

to determine, for example, if extractions were necessary. Through this step-by step approach, the Steiner analysis has been instrumental in “popularizing“ cephalometrics. At one time, southern California was known cephalomtrically as Steiner Territory”.

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History of Extraction in Orthodontics

History of Extraction in Orthodontics

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• Arch-Length Analyses • Second Premolar Extraction • Evolution of the Philosophy of Extraction in Conjunction with Orthodontic Therapy

– Case or Angle Controversy • Need for Extraction • Choice of Teeth for Extraction • Serial Extraction

Extraction of one or more teeth is sometimes necessary to establish normal functional occlusion, especially when jaws are not large enough to accommodate all the teeth. Tooth extraction may also be needed to correct the anteroposterior dental arch relationships. The space gained by extraction is utilized to relieve crowding or to retract the proclined anteriors. The decision of extraction should always be based on sound judgment, taking patient’s age, development and amount of space needed for tooth alignment into consideration. The decision to opt for extraction should be made only after careful clinical evaluation, cephalometric and model analysis to assess the need and outcome of such extraction. First premolars are most frequently extracted as a part of orthodontic treatment followed by the second premolars. Injudicious extractions may lead to undesirable consequences such as arch collapse, deep overbite, spacing and tissue damage. By the 1930s, the relatively common extraction practices of the late 19th century, dictated largely by technique limitations, had given way to Angle’s non-extraction dogma. Although a more tempered position continued to be held by Case and others, the word “extraction” had become all but unmentionable. Thus, when it was mentioned in the literature, it was frequently

15

• Historieal Perspective – Dewel’s Method 1978 – Tweed’s Method (1966) – Nance Method – Grewe’s Method

described euphemistically as “reduction in the total number of dental units”. According to Lischer, “The extraction of one or more permanent teeth to facilitate an orthodontic treatment dates back at least to Fauchard (1728), and has been resorted to ever since. . . . The narrow, orthodox view that extraction of a tooth is never justified is being discarded. . . . The profile of a growing child must never be regarded as a fixed line, but one in which further changes will continue to take place.” As early as 1920, George W Grieve (1870–1950, Angle School, 1907; Fig. 15.1), considered the dean of Canadian orthodontists, recommended the removal of permanent teeth. However, the increase in extractions that took place in the mid-1940s was due, in large part, to the influence of Charles Tweed, whose teachings had become widely accepted. He advocated positioning the mandibular incisors upright over basal bone (approximately 90° to the mandibular plane angle) and argued that expansion of dental units off this bone led to instability. Extractions in the permanent dentition rapidly became the most common treatment strategy for the correction of Class I and II malocclusions, and, as Allan Brodie ruefully remarked, “soon the air was filled with bicuspids”. The prevalence of extractions soared from a modest 30% in 1953 to 76% in 1968.

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Fig. 15.1: George W Grieve

Tweed did not extract indiscriminately, but, in too many patients, practitioners looked on the removal of 4 premolars as the easy way out of an arch-length problem. Conservative leaders, although acknowledging that extraction had its place, were reluctant to endorse it publicly, out of fear that it would lead to abuses. Brodie, who became Angle’s torchbearer, said, “If I say it’s OK to extract, the first thing you know, everybody’s going to be extracting instead of making a proper diagnosis. Doctor Angle told me that and it’s true”. By the 1980s, the pendulum had swung back toward non-extraction as orthodontists began using new appliances and technologies to increase arch length and width, making it easier to treat crowded dentitions without extractions. Several other factors were responsible for this shift, including some negative ones. • Relapses (including the return of rotations and overbite) and the reopening of extraction spaces. • Gingival depressions at extraction sites. • The finding that extraction is no guarantee of stability. • Flattened lips—”aged” look. The general public often prefers fuller and more

prominent lips. Abraham Goldstein studied patients 21 years after retention and found that non-extraction patients looked better. • Lack of incisor prominence. • Narrowed maxillary arch. • Desire to avoid extended treatment. • The increased fear of malpractice litigation. In the 1980s, claims were made that temporomandibular disorder problems could be attributed to the removal of maxillary premolars. But there were also some positive factors. • Increased use of extraoral traction and functional appliances to take advantage of growth. • More arch length gained by the use of bonded brackets. • Better understanding of retention. • Reproximation (e.g. air-rotor stripping, “slenderizing”). • Increased use of removable appliances (which rely mainly on a full complement of teeth). • Revival of “arch development”14 (lateral expansion, rotation or distalization of molars, and controlled proclination of mandibular incisors). By 1993, the prevalence of extraction had returned to 1950s levels (28%). Proffit and Fields believe that nonextraction is once again being carried to an extreme. ARCH-LENGTH ANALYSES In the 1950s, to a considerable extent a result of Silas J Kloehn’s (1902–85, Fig. 15.2) revival of cervical traction and Nance’s arch-length analysis, there was increased interest in mixed-dentition treatment and serial extraction. Perceiving a need for improvement in mixed-dentition tooth-size measurement, Hixon and Oldfather in 1958 developed an analysis based on the widths of the mandibular permanent incisors and the X-ray measurements of the unerupted canines and premolars, using a 16-in cone. This contribution proved to be the most popular of its kind to date; however, it was later revised because it was learned that this analysis often under predicted the widths of unerupted teeth. Moyers’ analysis (1973), based on linear regression equations and the widths of the mandibular incisors, achieved widespread

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extreme cases, a mandibular incisor might require extraction.

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SECOND PREMOLAR EXTRACTION

Fig. 15.2: Silas J Kloehn

clinical acceptance because of its simplicity and ease of application. Offering insight into why some occlusions did not “fit”, Wayne Bolton devised an analysis based on average measurements to determine tooth-size discrepancies between the maxillary and mandibular arches. This analysis made it possible to determine whether the maxillary or the mandibular teeth (commonly, the 6 anterior teeth) have deficient or excessive mesiodistal diameters. His analysis immediately became a standard part of the complete diagnostic analysis of malocclusion, although, in 2000, Smith et al, examining the validity of Bolton’s ratios for various ethnic groups, concluded that the ratios apply only to white women and should not be used arbitrarily for white men, Hispanics, or blacks. Peck and Peck, believing that tooth shape (rather than tooth width) might be a factor in determining whether crowding of the mandibular incisors would occur, devised an index based on the ratio between the mesiodistal and faciolingual widths. With this and Bolton’s ratios, it became possible to determine the need for re-proximation. In

A borderline patient presents the dilemma of extracting first premolars when the amount of crowding does not warrant the 14 or 15 mm per arch thus gained, or the alternative of nonextraction, which might be equally undesirable for reasons of esthetics or stability. The idea of extracting teeth other than the first premolars must have occurred to early clinicians, and some might very well have done so. Surely, many had to deal with congenitally missing second premolars. But it was well into the 20th century before it is mentioned the literature. One of the first authors to spell it out was Clarence W (Clu) Carey (1904–2003, Fig. 15.3). Carey was an innovator whose many contributions to orthodontics include laminated arches, the Bi-Po toothbrush, and the tooth-size dental calculator. He was nevertheless more cautious when he advocated (1947) extracting 4 second premolars if the discrepancy is more than 2.5 mm and if the operator is willing to accept a compromised result. In 1949, Nance spoke of removing the second rather than the first premolars to keep the incisors over basal bone. Perhaps the most definitive description of second-premolar extraction procedures during those years was written by B F (Tod) Dewel (1902–99, Fig. 15.4 ), who emphasized that closure of extraction spaces requires “a delicate balance . . . between anterior anchorage and posterior resistance”. He reminded us that “extraction of second premolars decreases by 2 teeth the resistance the buccal segments present when the spaces are being closed”. In 1964, Ricketts (1920–2003) advocated placing the mandibular incisors within 1 standard deviation of the Point A-pogonion plane. That same year, Schoppe suggested that a discrepancy of 7.5 mm or less should be the criterion for considering second premolar removal, if there is no need for incisor retraction. He offered these advantages for the option: • Permits more rapid mesial movement of molars. • Permits less lingual movement of incisors. • Is probably the best means of gaining space when a minimum of space is necessary.

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Fig. 15.3: Clarence W (Clu) Carey

• Tends to alter the profile less. • Tends to hasten closure of the extraction space. Reminiscent of Tweed’s “100 cases”, Logan showed 100 case records of patients treated with second premolar extractions at the 1970 annual Pacific Coast Society of Orthodontists’ meeting. In a 1973 article, he listed these advantages of second-premolar extraction, over and above those proffered by Schoppe. • Eliminates problems of rotated, tipped, or late-erupting second premolars. • Facilitates closure of anterior open bite by reducing posterior vertical dimension. • Eliminates need to bond mandibular second premolars, which are less-than-ideal candidates for bonding. • Gains additional space for second and third molars. • Makes it easier to control rotations, axial inclinations, and anterior torque. • Requires less Class II elastic force and headgear. • Produces fewer end-to-end bites because of the comparative widths of maxillary and mandibular premolars. • Maintains the maxillary first premolar, which is usually stronger than the second premolar. EVOLUTION OF THE PHILOSOPHY OF EXTRACTION IN CONJUNCTION WITH ORTHODONTIC THERAPY The role of extractions in orthodontic treatment has been a matter of controversy for years. Although John Hunter recognized the role of extraction as early as 1771 in his book Natural history of the teeth, it was not until mid 20th century that extraction of teeth in conjunction with orthodontic therapy became more acceptable. Case-Angle Controversy

Fig. 15.4: BF Dewel

Originally, Calvin Case (Fig. 15.5) was a genuine admirer of Angle. He advocated the Angle system at every turn and hoped to place this system before the dental profession. In fact, he gave up the general practice of dentistry because of Angle’s influence. The discord started over the claim that Angle attributed the origin of the use of inter-maxillary elastics to Baker, while Case

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History of Extraction in Orthodontics

Fig. 15.5: Calvin Case

Fig. 15.6: Martin Dewey

thought that he should have received that credit. In fact, when Angle described this procedure, he never mentioned Case. This led to charges and counter charges between them in 1903. Case’s claim was that in 1890 he started this procedure and reported it at the Chicago Dental Society and also at the Columbian Dental Congress in 1893. The second point of contention was—and is the one usually remembered—the question of the extraction of certain teeth as a means of treatment. Angle’s thesis was that “there shall be a full complement of teeth, and that each tooth shall be made to occupy its normal position”. Case defended the discreet use of extraction as a practical procedure, while Angle believed in nonextraction. However, the unexpected result of this controversy was that it convinced general practitioners that they should not attempt orthodontic treatment but should refer patients to the specialist. The extraction story was continued into 1911 with Martin Dewey (1881–1933) (Fig. 15.6) an ardent champion of non-extraction. Dewey served as professor of Orthodontics at Kansas City Dental School, the University of Iowa Dental

Department, the Chicago Dental College, and the New York College of dentistry. He gained a wide reputation as an outstanding teacher. He had started his own graduate school in orthodontics in 1911 as the Kansas City School of Orthodontia and continued it as he traveled from one city to another, ending in New York City with his death in 1933. His influence was much felt since he was the editor of the International Journal of Orthodontia for 17 years and also the president of the American Dental Association in 1931. The climax of this conflict was a debate in 1911 at the annual meeting of the National Dental Association (former name of the ADA). Bitterness and animosity were rampant. It took many years after this episode for the problem to become a matter of calm and objective evaluation and respectful appreciation of various points of view, each of which has made its contribution to orthodontics. The first decade of the twentieth century was an era of the manufacture of standardized appliances. These appliances were made as sets of various kinds mounted on cards and sold by dental supply companies. By the use of a few

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simple soldering techniques, the dentist could make a required “fitting”, as it was called. William J Brady (Iowa City) advertised as a consulting specialist in orthodontia: Advice by mail upon regulating cases of all kinds. Appliances fitted to models with full instructions for handling from beginning to end. Instructions: send good models of both upper and lower, with thin wax bite. Give age and sex. Pack carefully. After examination, an estimate of the cost of instructions of appliance will be submitted free of charge. If satisfactory, remit the amount by bank draft or money order. George C Ainsworth patented a regulating appliance that used vertical tubes and the principle of the loop wire in 1904.Varney Barnes patented the so-called Barnes posterior tube consisting of a soldered band that held several teeth together, with vertical tubing applying root pressure to individual teeth. Many innovative ideas and procedures were introduced. Victor H Jackson (1850–1929) was experienced in mechanics and devised a specially designed appliance known as the Jackson crib, which incorporated the use of an auxiliary spring (finger) as an aid in tooth movement. His appliance was one of the first “systems” of treatment to influence the development of modern orthodontics. Jackson published Orthodontia and Orthopaedia of the Face in 1904. In it, he claimed that with his method a large number of patients could be cared for as contrasted to the highly sophisticated techniques in vogue at the time that limited the number of patients. Another contribution was reintroduction of the maxillary suture opening by Herbert A Pullen (1874–1938) in 1902. Charles A Hawley (1861–1929) used a celluloid sheet containing a geometric figure that, when adapted to a model determined the extent of proposed tooth movement (1905) and introduced the retainer appliance that bears his name (1908). Scientific studies included research in dental histology, particularly by Frederick B Noyes (1904); the influence of heredity and environment on dental structures (1905); emphasis on rhinology, which brought the medical fraternity into cooperation (1907); the study of the deciduous dentition vis-a-vis nasodental growth, especially by Edward A. Bogue (1838–1921); and

the diagnosis of “mouth breathing”, which took on special meaning (1907). In 1907 Benno Lischer (1876–1959)(Figure 14.7), dean and professor of dental orthopedics at Washington University Dental School in St. Louis, founded the International School of Orthodontia, and in 1912, he published Principles and Methods of Orthodontia. He was an advocate of early treatment. Lischer wrote: “It is my firm belief that irreparable damage is done by oft repeated advice to wait until the permanent teeth are all erupted before beginning operations for correction of malocclusion.” Other publications included the first separate journal entitled American Orthodontist, which started in 1907 and ceased publication in 1912. In 1909 CN Johnson (Chicago) edited a work entitled A Textbook of Operative dentistry, which contained a chapter, “Orthodontia”, written by Herbert A Pullen covering over 275 pages of text. It contained not only etiology, diagnosis, and treatment modalities but also instruction in laboratory procedures. NEED FOR EXTRACTION Extraction of teeth in orthodontic treatment is necessary in two main circumstances: 1. For the relief of crowding caused by arch lengthtooth material discrepancy 2. For the correction of anteroposterior dental arch relationship. CHOICE OF TEETH FOR EXTRACTION The choice of teeth for extraction should be carefully made with consideration to the following factors: • The amount of tooth material excess in relation to arch length, degree and site of crowding. • The anteroposterior inter-arch relationship. • Profile of the patient. • Age of the patient and his/her dental developmental status. • The direction of jaw growth. • Carious status of the teeth. • General health status of the dentition. SERIAL EXTRACTION Serial extraction is an interceptive orthodontic procedure undertaken in the (early) mixed

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History of Extraction in Orthodontics

dentition period that involves planned removal of certain primary and permanent teeth in a programmed sequence, so as to relieve crowding in the arches and to guide the remaining erupting permanent teeth into a more favorable position. A thorough understanding of the dynamics of orofacial growth and development and that of the stomatognatic system is essential for the success of serial extraction procedures. When executed properly in carefully selected patients with the proper assessment, skilled timing and careful monitoring, programmed serial extraction procedures can produce best possible and most stable results with minimal or in some cases no further need of corrective mechanotherapy at a later stage when all permanent teeth erupt. Although occasionally used to intercept Class II and Class III malocclusions, serial extraction procedure is mainly used to intercept and/or treat Class I malocclusions with crowding resulting from severe tooth size arch length discrepancy. Definition • Tweed: Serial extraction as ‘the planned and sequential removal of the primary and permanent teeth to intercept and reduce dental crowding problems.’ • Iondon: The correctly timed, planned removal of certain deciduous and permanent teeth in mixed dentition cases with dentoalveolar disproportion. HISTORICAL PERSPECTIVE Robert Bunon in the early 1743 advised extraction of primary teeth to achieve a better alignment of permanent teeth in his diseases of teeth (Table 15.1). Later several authors like Bourdet (1757), Hunter (1771), Robinson (1846) and Harris (1855) advocated removal of primary canines and the premolars when permanent incisors crowded. The term “serial extraction” was first coined by Kjellgren in 1929. However it was Nance who popularized the procedure in 1940’s in England and is considered as the Father of Serial Extraction technique practiced today.

Although popular, the term “serial extraction” does not stress the importance of thorough knowledge of growth and development, comprehensive analysis based on investigative records required to execute the procedure properly and thus may be misleading. Hotz (1970) recommended the term “guidance of eruption”. It is also sometimes referred to as “guided extraction”, while other authors prefer to call the procedure “Guidance of Occlusion”. Dewel’s Method 1978 Dewel’s has proposed a three step serial extraction procedure in 1978 (Table 15.2). Step 1: In this step the deciduous canines are extracted to create space for the alignment of the incisors (Fig. 15.7A). The main objective of extracting primary canines is to establish the integrity of upper and lower incisors. This prevents development of lingual cross bite of maxillary laterals and resultant mesial migration of maxillary canines. Step 2: In this step deciduous first molars are extracted at 8-9 years of age. The objective of Table 15.1: Authors and their inventions Authors

Diseases of teeth

Robert Bunon (1743) First reference to extraction of primary teeth to facilitate alignment of permanent teeth Kjellgren (1929) First coined the term Serial Extraction Nance (1940s) Popularized the procedure considered father of serial extraction technique Hotz (1970) Argued against the term serial extraction to call it guidance of eruption Table 15.2: Dewel’s method Steps

Tooth extracted

Step 1 Extraction of deciduous canines Step 2 Extraction of deciduous first molars Step 3 Extraction of first premolars

Purpose Alignment of incisors To facilitate the eruption of first premolars ahead of permanent canines To facilitate eruption of permanent canines

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A

B

D

C

E

Figs 15.7A to E: Dewel’s method of serial extraction: (A) Deciduous canines are extracted to create space for the alignment of the incisors; (B) Deciduous first molars are extracted to facilitate eruption of first premolars; (C) First premolars are extracted to facilitate the eruption of permanent canines; (D) Favorable eruptin of canines after removal of first premolars; (E) Proper occlusion after minimal period of fixed orthodontic mechanotherapy

deciduous first molar extraction is to accelerate eruption of first premolars. This ensures that the first premolars emerge into oral cavity ahead of the permanent canines (Fig. 15.7B). Step 3: In this step first premolars are extracted to facilitate the eruption of permanent canines (Fig. 15.7C). After serial extraction procedure, the teeth are fairly aligned (Fig. 15.7D). However, establishment

of proper intercuspation usually requires orthodontic mechanotherapy of minimal duration (Fig. 15.7E), although it may not be necessary in rare cases. TWEED’S METHOD (1966) This method involves the extraction of the deciduous first molars at 8 years of age. This is

History of Extraction in Orthodontics

followed by the extraction of the first premolars and the deciduous canines simultaneously. Nance Method Nance method of serial extraction is a modification of Tweed’s method which involves the extraction of the deciduous first molars followed by the extraction of the first premolars and the deciduous canines.

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Grewe’s Method Grewe’s method of serial extraction is based on the planning of extraction sequence for different clinical conditions. 1. Class 1 malocclusion with premature loss of a mandibular deciduous canine. Class 1 malocclusion with premature loss of a mandibular deciduous canine will result in midline shift, when the arch length discrepancy is 5–10 mm/arch, then the remaining deciduous canines should be extracted the deciduous first molars are extracted next, if the first premolar have their roots more than half formed. If the roots of the first premolars are not developed more than half then extractions of the deciduous first

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molar is delayed. The first premolars should be extracted as they emerge. 2. Class 1 malocclusion with severe mandibular anterior crowding. Deciduous Canines are extracted when there is arch length deficiency and more than 5 mm per quadrant. The deciduous first molars are extracted next on completion of at least half of first premolar root formation and the extraction of first premolars follow as the erupt into the oral cavity. 3. Class 1 malocclusion where minimal mandibular anterior crowding is 6–10 mm arch deficiency. In such conditions the first premolars are extracted. The deciduous first molars are extracted when the roots of the premolars are more than half formed, as this would in turn result in premature loss or eruption of the first premolar as soon as the first premolars erupt into the oral cavity; these are extracted followed by deciduous canines. If this is bound to be eruption of permanent canines before that of first premolar, then the deciduous canine is extracted first followed by the extraction of the deciduous first molar and encleation of the first premolar.

History of Expansion Appliances

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• Wescott’s Expansion Device • Angell’s Palatal Expansion Device – Goddard Expansion Device – Kingsley’s Extraoral Traction Appliance

16

– Kingsley’s Incline Plane – Herbst’s Retention-Joint Appliance – Coffin Appliance • Fixed Rapid Maxillary Expansion Appliances

WESCOTT’S EXPANSION DEVICE

ANGELL’S PALATAL EXPANSION DEVICE

Wescott first reported the placement of mechanical forces on the bones of the maxilla, in 1859. He used two double-clasps separated by a telescopic bar to correct a cross bite in a 15-year-old girl. One double clasp was soldered to the tube and the other was soldered to a screw that fit into the tube, thereby allowing lengthening of the screw to widen the palate. Adjustable spurs were also attached perpendicular to the telescopic bar to allow forward repositioning of the incisors (Fig. 16.1).

A year later, Angell’s performed a similar procedure with a differentially threaded jackscrew connected across the palate to both bicuspids on one side and the second bicuspid on the other (Fig. 16.2). The patient was given a key to turn the screw and instructed to keep it uniformly firm. Upon her return, 2 weeks later she had developed a space between her central incisors, which Angell claimed “showed conclusively that the maxillary bones had separated”. Goddard, in 1893, further standardized the palatal expansion protocol. He activated the device twice a day for 3 weeks, followed by a consolidation period to allow the deposition of “osseous material” in the created gap. The description of his appliance is similar to Hyrax appliance, being attached to the first bicuspids and second molars bilaterally. In addition to palatal expansion, two other orthodontic techniques utilized traction for the correction of craniofacial skeletal deformities. In 1866, Kingsley first applied extraoral traction to correct the protrusion of the maxilla. His appliance consisted of a gold frame that covered the incisors and a head cap, which was connected to the frame by elastic ligatures (Figs 16.3A and B).

Fig. 16.1: Wescott’s expansion device

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Fig. 16.2: Angell’s palatal expansion device placed on the maxillary teeth

A

Nine years later, Potpeschnigg described a “Tooth Regulating Machine” that consisted of a head cap connected to a steel rod, that was secured to the tooth by means of an elastic ring. Traction was applied to the tooth by tightening the elastic band between the head cap and metal rod (Fig. 16.4). In 1892, Kingsley successfully used principles of traction to treat mandibular retrognathia, with a functional appliance. He developed an inclined plane attached to the upper arch to force the entire mandible forward as the patient closed his mouth. Thirteen years later, Herbst demonstrated his “retention-joint appliance” which consisted of two telescoping rods attached to the teeth (Fig. 16.5). As the patient closed his mouth, the mandible was forced forward into a normal position.

B

Figs 16.3A and B: Kingsley’s extraoral traction appliance (A) and Potpeschnigg’s “tooth regulating machine” (B)

Fig. 16.4: Kingsley’s incline plane

Fig. 16.5: Herbst’s “retention-joint appliance”

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Arch expansion is one of the methods of gaining space in orthodontics. The concept of arch expansion was explained for the first time by Emerson C Angel. Hence, he is considered as father of expansion appliances. Arch expansion can be slow or rapid, removable or fixed. Slow arch expansion brings about mainly dentoalveolar expansion whereas rapid maxillary expansion brings about both skeletal as well as dentoalveolar expansion. Rapid maxillary expansion appliances are the best appliances of the orthopedic expansion. In this, changes are produced mainly in the underlying skeletal structures rather than by the movement of teeth through the alveolar bone. Rapid maxillary expansion not only separates the midpalatal suture but also affects the circumzygomatic and circummaxillary sutural systems. Rapid maxillary expansion is also called palatal expansion or split palate. Rapid maxillary expansion is a skeletal type of expansion, which produces skeletal changes by separation of mid palatal suture. Rapid maxillary expansion device was first used by Emerson C Angel in the year 1860. He used a jackscrew type of rapid maxillary expansion device between two premolars in maxillary arch on palatal side in a 14-year-old girl and achieved arch expansion by ¼ inch in 14 days. For this significant valuable contribution to the expansion in orthodontics, he is considered as the Father of rapid maxillary expansion. Walter Coffin in 1877, developed a spring for the purpose of arch expansion which has come to be known as Coffin spring. This spring also produces arch expansion by separation of mid palatal suture, when used in young patients. This expansion device was of gained popularity by

Fig. 16.6: Derichsweiler type expander

orthodontic community at that time. Later in 1956, this expansion device was reintroduced to orthodontics by Andrew Hass, in the United States of America. Removable expansion appliance may be a simple expansion appliance with incorporated jackscrew or Coffin appliance. Fixed arch expansion appliances are toothborne expansion appliance (Hyrax, Isacson) or tooth and tissue borne expansion appliance (Derichsweiler Haas expansion appliance). How much to expand and when to expand are evaluated by model analysis. FIXED RAPID MAXILLARY EXPANSION APPLIANCES Fixed rapid maxillary expansion appliances are fixed expanders and cannot be removed by the patient. These fixed expanders can be classified into tooth and tooth tissue-borne appliances. Tooth and tissue borne appliances are: • Derichsweiler type • Haas type. Most commonly used fixed expander of tooth borne appliances are: • Hyrax type • Isaacson type. Derichsweiler-type expander: Derichsweiler expansion appliance consists of molar bands on right and left permanent first molars and first premolars with wire tags soldered into the palatal surface of all molar and premolar bands. The outer free ends of wire tags are inserted into split palatal acrylic incorporating a jack expansion screw in its center (Fig. 16.6). Haas-type expander: Haas expander was designed and popularized by Andrew Hass in the year 1961. This appliance consist of molar bands on right and left permanent molars and premolars. A jackscrew is incorporated in the midline into the two acrylic pads that closely contact the palatal mucosa. Support wires also extend anteriorly from the molars along the buccal and lingual surface of the posterior teeth, to add rigidity to the appliance (Fig. 16.7). Haas states that, more bodily movement and less dental tipping is produced when acrylic palatal coverage is added to support the appliance thus permitting the forces to be generalized not only against the teeth but also against the underlying soft and hard palatal tissues

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Fig. 16.8: Hyrax expander

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Fig. 16.7: Hass expander

Hyrax–type expander: The more commonly used type of banded RME appliance is the Hyrax–type expander. This type of expander is made entirely from stainless steel. Bands are placed on the maxillary first molars and first premolars. The expansion screw is localized in the palate in close proximity to the palatal contour. Buccal and lingual wires may be added for rigidity (Fig. 16.8). Isaacson expansion appliance: It is a fixed tooth borne appliance without acrylic covering. This appliance consists of molar bands on first right and left, permanent molars and premolar bands on right and left permanent premolars. Metal flanges are soldered into the molar and premolar bands (14, 16, 24, and 26) on buccal and palatal sides (Fig. 16.9). A spring loaded expansion screw (Minne) expander having a nut which can compress the spring and is made to extend between palatal metal flanges. Activation: It is activated by closing the nut, so that the spring gets compressed. Bonded rapid maxillary expansion: These appliances consist of an acrylic splint covering variable number of teeth on either side in the maxillary arch, to which a jack screw is attached. Splint can be either cast cap made of silver copper alloy or acrylic splint made of polymethyl methacrylate (Fig. 16.10). A wire framework may be adapted around the teeth to reinforce the acrylic.

Fig. 16.9: Isaacson expansion appliances

Fig. 16.10: Bonded rapid maxillary expansion appliances

Expansion Screw A typical expansion screw (Figs 16.11A to D) consists of an oblong body, divided into two

halves. Each half has a threaded inner side that receives one end of a double ended screw. The

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History of Orthodontics

A

B

C

D Figs 16.11A to D: Different types of expansion serews

A

B

Figs 16.12A and B: (A) Expansion screw key; (B) Showing activation of expansion screw by placing the key in the hole

screw has central bossing with four holes. These holes receive a key called expansion screw key (Figs 16.12A and B) which is used to turn the screw.

Various types of expansion screws are available to carry out different types of expansion as enumerated in Table 16.1.

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Table 16.1: Different types of expansion screws

Table 16.2: Timm’s schedule of activation of expansion screw

Expansion screw type

Use

Symmetrical bilateral expansion screw

Bilateral expansion

Age of the patient

Degree of activation

Number of activation in a day

Traction screw

Closing spaces

Up to 15 years

90o

2 times in a day

Expansion screw with split activator

Separate expansion of maxilla or mandible

o

4 times in a day

Three-dimensional screw

Anterior and bilateral expansion

More than 15 years

45

Table 16.3: Expansion orthodontic appliances

Expansion Screw Activation Schedule Schedule by Timms

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See Table 16.2. Expansion Orthodontic Appliances Expansion orthodontic appliances (Table 16.3) are used to relieve crowding in cases of arch length—tooth material discrepancy. Following are the researchers involved in the development of various type of expansion appliances.

Author S.No. Type of expansion appliance

Contributions to orthodontics Developed by

1

Derichweiler

2 3 4 5

Derichweiler expansion appliance Isaacson’s expansion appliances Haas expansion appliance Coffin spring Jack expansion screw

Isaacson Haas Walter coffin Jack

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History of Removable Orthodontic Appliances

• Development of Removable Orthodontic Appliances – Victor Hugo Jackson – George Crozat – Robin – Andersen – Adam – Martin Schwartz – Indications

Removable orthodontic appliances are so-called because they are designed to be fitted and removed by the patient. Removable orthodontic appliances are limited to tipping and simple rotatory movements of teeth, which are sufficient for many orthodontic treatments. They depend on cooperation and a certain degree of skill on the part of patient. Removable orthodontic appliances may be active or passive. The use of removable orthodontic appliances was always more popular in Europe than the United States, but even there, the use of fixed appliances [using (generally metal) bands and brackets] has largely become the primary method of treatment. Nevertheless, as the authors of Removable Orthodontic Appliances point out, removable appliances are often an effective means of addressing many patients’ needs and in some cases have considerable advantages over fixed appliances. Use of removable appliances also requires careful case selection for, success of the treatment. They are ideally used when simple tipping movement of teeth is sufficient to correct a certain

17

– Contraindications – Advantages – Disadvantages • Components of Removable Orthodontic Appliances – Retentive Components – Active Components – Base Plate

type of malocclusion. The range of malocclusions that can be treated with removable appliance alone is limited. They can also be used as passive appliances to maintain teeth in their corrected positions after active phases of orthodontic therapy, e.g. retainers. Removable orthodontic appliance is often used in conjunction with fixed mechanotherapy. The most familiar removable device is the retainer, specifically the Hawley or Begg device. Its function, however, is retention—keeping teeth in their place after the desired tooth-movement has been achieved. The main drawback of removable orthodontic appliances is that they can only apply a tipping force (whereas fixed appliances can also apply a rotating force), this means they are not suitable for the complete treatment of some cases (specifically, serious class II and III cases). Among the big advantages of removable orthodontic appliances are in the area of anchorage (since the palatal area is also used for this), significant since fixed appliances must generally rely on adjacent teeth (As the authors note, the use of removable

History of Removable Orthodontic Appliances

appliances generally involves the upper arch; lower arch treatment with them is limited by difficulties with retention and bulk, as well as the limited space available for active components on the appliances themselves).

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DEVELOPMENT OF REMOVABLE ORTHODONTIC APPLIANCES Removable orthodontic appliances begin with a brief general introduction, and then discusses the ‘Biomechanics of tooth movement’, various active components that can be utilized, and how they function and are integrated into devices, including a variety of springs, bows, and screws. The next survey ‘Appliance retention’, ‘The baseplate’, and ‘Anchorage’, discussing the factors that should be taken into consideration which designing the device, both generally (going so far as to note: “Removable appliances should ideally be fitted within two weeks of the impression being taken”) and also in tailoring it to the individual case. Anchorage issues, in particular, must be closely monitored from visit to visit, and as the authors point out: “if space is critical, it may be wise to plan for extraoral anchorage from the start”. Clearly, the use of extraoral anchorage headgear, which in the case of removable appliances cannot be cervical (since the pull must be upwards so as not to displace the appliance) allows for much greater flexibility in treatment, as headgear can be used as the sole source of anchorage or to reinforce intraoral anchorage, as well as extraoral traction be an active component for tooth movement. Victor Hugo Jackson Victor Hugo Jackson is from United States of America. He was the chief proponent of removable appliances. • At that time, neither the modern plastics for base plate material nor stainless steel wireclasp, springs were available. • Appliances are fabricated with bases and precious metal or nickel silver wires. • In early 20th centuries. George Crozat In early 1900s, Crozat developed a removable appliance fabricated entirely of precious metal

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that is still used occasionally. Crozat appliance consists of: – Modified Jackson’s clasp. – Heavy gold wire framework. – Lighter gold finger springs to produce desired tooth movement. Robin In the year 1900, forerunner of all functional appliances, the monobloc was developed by Robin. Andersen In the 1920s, andersen developed activator in Norway. He was the first person to develop functional appliance. Adam In the 1921s, Adam developed a clasp called Adam’s clasp. Martin Schwartz • He developed split plate appliance. Indications of Removable Orthodontic Appliances Use of removable orthodontic appliances requires careful selection. They should not be used in circumstances where fixed orthodontic appliance therapy would be more appropriate. May be used as an adjunct to fixed orthodontic appliance treatment. Contraindications of Removable Orthodontic Appliances Removable orthodontic appliances are contraindicated in case, where bodily movement is required. Advantages of Removable Appliances Advantages of removable orthodontic appliances are listed below: 1. Removable appliances permit easy cleaning. 2. They need less chair side time. 3. They are good for overbite reduction. 4. They can tip the teeth efficiently. 5. They eliminate occlusal interferences.

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Disadvantages of Removable Orthodontic Appliances

Retentive Components

Disadvantages of removable orthodontic appliances are listed below: 1. Removable orthodontic appliances can bring about only a limited type of tooth movement. 2. Anchorage of tooth movement is sometimes difficult, since anchor teeth cannot be prevented from tilting. 3. Retention with removable orthodontic appliance is more difficult than with fixed appliances. 4. A high degree of cooperation and a certain amount of skill is required from the patient, who has to remove, clean and replace the appliance at frequent interval. 5. Limited scope on lower arch. 6. They affect speech.

• Jackson describes the construction of a crib clasp which has a square form and is designed not only to grasp the tooth buccally but, by running forward and backward and turning sharply at a right angle, to grasp the tooth anteroposteriorly. The next real advance in clasp design was the introduction of the arrowhead type of clasp, usually attributed to Schwarz and introduced in England by Tischler. • The arrowheads depend on the use of the spaces below the point of contact between two teeth. Several arrowheads are usually embodied in a clasp. • The modified arrowhead clasp, introduced by Adam in 1949 and today widely referred to as the Adam clasp, makes use of the mesial and distal undercuts of a single tooth only and can in practice be applied to any tooth, deciduous or permanent. The success of a removable orthodontic appliance mainly depends upon good retention of the appliance. Adequate retention of a removable orthodontic appliance is achieved by incorporating certain wire components, got engaged the undercuts on the teeth. These wire components that help in retention of a removable appliance are called clasps. Following are the different type of clasps which aids in retention to the appliance: i. ‘C’clasp or Circumferential clasp ii. Jackson’s clasp or Full clasp iii. Adam’s clasp iv. Schwartz clasp v. Crozat clasp vi. Triangular clasp vii. Ball end clasp viii. Resta clasp ix. Eyelet clasp x. Southend clasp.

Advantages of Removable Appliances a. They are removable and therefore easier to clean. b. They can provide increased vertical and horizontal anchorage due to palatal coverage. c. They can produce efficient over-bite reduction in a growing child. d. They can transmit forces to blocks of teeth. Disadvantages of Removable Appliances a. b. c. d.

The appliances can be left out. Only tilting movements are possible. They affect speech. A technician’s input is required to make the appliances. e. Intermaxillary traction is more difficult. f. They are inefficient for multiple tooth movements. g. Lower removable appliances are more difficult to tolerate. COMPONENTS OF REMOVABLE ORTHODONTIC APPLIANCE Removable orthodontic appliance consists of following three components: 1. Retentive components 2. Active components 3. Base plate.

Evolution of Clasp Design

Modifications of Adam’s Clasp and its Use Adam’s clasp offers a unique feature that, its design can be modified in a number of ways suit varies clinical requirements. The following are some of the modifications of Adam’s clasp.

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They can also be used for space closure in the anterior segment as well as space distal to canines. The following are some of the routinely used design of labial bows (Table 17.1): 1. Short labial bow 2. Long labial bow 3. Split labial bow 4. Modified split labial bow 5. Reverse labial bow 6. Robert’s retractor 7. Mill’s retractor 8. High labial bow 9. Fitted labial bow.

1. Adam’s clasp with incorporated helix Use: For the attachment of elastics. 2. Adam’s clasp with soldered hook Use: For attachment of elastics. 3. Adam’s clasp with traction hook Use: For attachment of elastics. 4. Adam’s clasp with additional arrowhead Use: For additional retention. 5. Adam’s clasp with single arrowhead Use: For partially erupted teeth. 6. Adam’s clasp with soldered buccal tube Use: For attachment of face bow. 7. Double Adam’s clasp on maxillary central incisor Use: For additional retention. 8. Adam’s clasp with distal extension Use: For attachment of elastic and additional retention.

Springs

Active Components Bows Bows are one of the active components of removable orthodontic appliance. They are usually used for overjet retraction of anteriors.

Springs are active components of removable orthodontic appliances which are used to bring about tooth movement. There are different types of springs (Table 17.2) which can be used according to the need. The basic principle behind using springs is that, when a wire is deflected, it tries to regain its prefabricated original shape and while trying to do so, the springs move the teeth along their path.

Table 17.1: Different types of labial bows Type of labial bow Wire used for fabrication

Description of the bow

Activation

Short labial bow 23 gauge hard It extends from Reduction of round stainless permanent lingual palatal steel or 0.7 mm canine to canine acrylic of anteriors Compression of both U loops Long labial bow 23 gauge hard It extends from round stainless first permanent steel or 0.7 mm premolar to premolar

Flexibility

Indications

Less flexible than any other type of labial bows

Minor overjet reduction (upto 3.5 mm) Mild space closure in the anterior segment

Reduction of More flexible lingual palatal than short acrylic of labial bow anteriors Compression of both U loops

Split labial bow 23 gauge hard The bow is split Reduction of More flexible round stainless in midline lingual palatal than short steel or 0.7 mm acrylic of labial bow anteriors Compression of both U loops

Minor overjet reduction Minor anterior space closure Closure of space distal to canine Anterior retraction

Contd...

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History of Orthodontics

Contd...

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Type of labial bow Wire used for fabrication

Description of the bow

Activation

Flexibility

Indications

More flexible than short, long and split labial bow

Mainly used for closure of midline diastema

Modified split labial bow

23 gauge hard The bow is Reduction of round stainless modified to lingual palatal steel or 0.7 mm engage the acrylic of opposite central anteriors incisors Compression For example, of both right bowwill U loops engage left central incisor below the contact point and vice versa

Reverse labial bow

23 gauge hard It extends from round stainless permanent steel or 0.7 mm canine to canine or permanent premolar to premolar The bow is reversed

Reduction of More flexible lingual palatal than short, acrylic of long, split, anteriors modified split Opening the labial bow loop resulting in lowering the bow incisally and compensatory bend is given to maintain proper level of bow

Overjet reduction (5 to 7 mm)

Robert’s retractor

23 gauge hard It extends from round stainless permanent steel or 0.5 mm canine to canine It incorporates an helix on either side The diameter of both helix should be 3 mm

Reduction of lingual palatal acrylic of anteriors Closing both the helices

More than short, long, split, modified split and reverse labial bow

Increased overjet (7 to 9 mm)

Mill’s retractor

23 gauge hard Bow having round stainless extensive steel or 0.7 mm looping

Reduction of lingual palatal acrylic of anteriors Compression of looping

More than Large overjet short, long, split, (more than 9 mm) modified split, reverse labial bow and Robert’s retractor

High labial bow with apron spring

21 gauge hard Extends in round stainless buccal steel or 0.9 mm vestibule Apron spring Apron springs fabricated with are made to 0.4 mm rest on incisors

Activated only by apron spring Apron sping is activated by bending it toward the teeth

Apron spring is Proclined incisors highly flexible because it is fabricated with thinner gauge wire

Fitted labial bow

23 gauge hard round stainless steel or 0.7 mm or 21 gauge hard round stainless steel or 0.9 mm

It is not activated

Least as compared to all other types of bows

It is made to be fitted in the contour of all anteriors

Mainly used for retention after completion of fixed orthodontic therapy

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Table 17.2: Different types of springs and their activation and indications Type of spring

Wire used for fabrication

Description of the spring

Activation

Indication

Finger spring

0.5 mm or 0.6 mm stainless steel wire

Consist of active arm, helix and retentive arm Helix is of 3 mm in diameter and should rest on the long axis of root of the tooth to be moved Retentive arm is of 4-5 mm in length and is made to get embedded in acrylic base

Closing the helix and moving active arm towards the tooth to be moved

Closure of midline diastema Closure of minor anterior space

Z spring

0.5 mm or 0.6 mm stainless steel or

Consists of two helixes arranged in pattern of Z that’s why also known as double cantilever spring

Activation depends on its indication For correction of minor rotation then only one upper helix is activated by opening the helix For labial movement of incisors the spring is activated by opening both the helixes

Correction of minor rotation Labial movement of incisors Labial movement of tooth in case of single or segmental cross bite

T spring

0.5 mm or 0.6 mm stainless steel wire

It consists of T shaped arm

Pulling the free end of T towards the intended direction of tooth movement

Buccal movement of premolars

Mattress spring

0.6 mm round stainless steel wire

It is shaped like a mattress with ‘U’ loops extending up to the retentive

——

Labial movement of upper teeth in cross bite

Helical coil spring

0.6 mm round stainless steel wire

Free-ended spring with two helixes formed on different arms

——

Regain the lost space

Canine Retractors Canine retractors are springs that are used to move canines in a distal direction. They can be classified in a number of ways (Table 17.3). Usefulness of canine retractors depends on the angulations of the canine to be retracted. The

removable orthodontic appliance with canine retractor can be efficiently used only when the canine is mesially angulated. When used on upright or canines, the removable canine retractors can worsen the situation. Thus fixed orthodontic appliances with greater control over tooth movement are preferred over removable canine retractors.

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Table 17.3: Classification of canine retractors

Base Plate

According to their location, canine retractors can be classified as: Buccal placed buccally Palatal placed palatally

Base plate has a greater percentage of bulk in removable orthodontic appliance than other components. The design of base plate varies with the type of removable orthodontic appliance. Self cure or auto polymerizing acrylic resins are used for the fabrication of base plate. It joins all other (active and retentive) components of removable orthodontic appliance together into a single functional unit.

According to presence of helix or loop: a. Helical canine retractor b. Looped canine retractor According to their mode of action: a. Push type b. Pull type

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The following are some of the commonly used canine retractors (Table 17.4) 1. ‘U’ loop canine retractor 2. Helical canine retractor 3. Palatal canine retractor 4. Buccal self-supported retractor

Table 17.4: Different types of canine retractors and their activation and indications Type of canine retractor

Wire used for fabrication (in mm)

Description of canine retractor

Activation

Indication

U loop canine retractor

0.6 or 0.7

It consists of U loop, active arm and retentive arm which is distal

Closing the loops 1 to 2 mm or cutting the free ends of active arm by 2 mm and readapting it

For canine retraction

Helical canine retractor

0.6 or 0.7

It consists of a coil of 3 mm diameter and active arm (towards the tissue) and retentive arm

Opening the helix by 1 mm or by cutting 1 mm of free ends and readapting it

For shallow sulcus in mandibular arch

Palatal canine retractor

0.6 or 0.7

It consists of a coil of 3 mm diameter, active arm and guide arm

Opening the helix 2 mm at a time

For retraction of palatally placed canine

Buccal canine retractor

0.6 or 0.7

It consists of a coil of 3 mm diameter, active arm (away from the tissue) and retentive arm

Opening the helix or closing the helix 2 mm at a time

For retraction of buccally placed canine

Buccal selfsupported canine retractor

0.6 or 0.7

It consists of a coil of 3 mm diameter, active arm (away from tissue) and retentive arm

Activation by closing helix 1 mm at a time

For retraction of buccally placed canine

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History of Fixed Orthodontic Appliances • • • • •

E-arch Appliance • The Concept of the Ideal Arch – Comparison of Architectural Pin and Tube Appliance and Dental Arches Ribbon Arch Appliance – Cause for Collapse of Arches Edgewise Appliance – Ideal Arch Form What was Orthodontics before • The Ideal Arch Wire Angle System? – Characteristics of an Ideal • Evolution and Development of Arch Wire the Edgewise Appliance – Arch Wire Bends • Evolution of Bracket • Advantages and Disadvantages • Evolution of Edgewise Buccal of Edge- wise Appliance Tubes

For the first third of this past century, orthodontics found itself dominated by one man, Edward H Angle (Fig. 18.1), with the resultant intellectual stagnation that arises from such monomaniacal control. This recognition in no way detracts from Angle’s contributions—notably his clear and simple classification system along with the edgewise bracket. Both of these inventions have endured for a century, and that is no mean achievement in any scientific discipline. Nevertheless, orthodontists’ unquestioning acceptance of his limited diagnostic and treatment planning regimens hindered the advancement of this discipline more than it helped, and the last half of this past century was spent trying to overcome the stupor of the first half. Angle’s influence continued until an apostate student of his, Charles H Tweed, had enough courage and objectivity to challenge Angle’s nonextraction scheme. It was not a tremendous leap of intellectual power. Tweed simply and honestly

18

• Building Treatment into the Edgewise Appliance • History of Begg Appliance • Straight Wire Appliance • Andrews’s Six Keys to Optimal Occlusion • Limitations of Straight Wire Appliance • History of Lingual Technique

Fig. 18.1: Edward H Angle

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recognized that when 100 percent of your patients relapsed, there might be something wrong with the diagnosis and/or treatment planning. Dr Tweed (Fig. 18.2) acted appropriately in the face of this challenge—quite unlike the ancient dentist who chided a young colleague who was describing his meticulous technique of endodontic filling to the monthly assembly of dentists. The old man explained his own technique that used a simple matchstick sharpened with a pocketknife and then jammed into the canal. When the young dentist asked if a lot of these root canal fillings did not subsequently fail, the older man replied, “Every damn time!” Tweed tired of those orthodontic abscesses and, unlike his peers, sought to correct the deficiencies he saw in Angle’s philosophy. Some would say that he overcorrected, but that said, we must pay homage to anyone who has the skill and temerity to successfully challenge a mentor and his minions. Tweed’s success brings to mind the remark of C S Lewis, who said, “No genius is so fortunate as he who has the skill and ability to do well that which others have been doing poorly”. Nevertheless, I do not think that Tweed would have ever been able to deliver his paper describing his extraction technique if Angle had still been alive. Angle’s influence over the society

Fig. 18.2: Dr Tweed

that bore his name was too immense to permit such hubris from a young upstart. But as Samuelson, the MIT economist, once noted: “Science progresses slowly—funeral by funeral.” And so it was and is in orthodontics. Non-extraction Philosophy Aside from the edgewise bracket and the classification system, Angle’s most enduring legacy has been his belief in non-extraction therapy. Angle had unsuccessfully experimented with premolar extractions while using his ribbon arch appliance, but he never solved the problem of paralleling the roots to prevent the extraction spaces from opening. If he could not do it, then, ergo, no one else could, and this resulted in a virulent opposition to any extractions and an insistence upon enlarging the arches to accommodate all of the teeth. This dogma stayed dominant for several decades until Tweed advocated the extraction of premolars based on his diagnostic triangle, which was the first systematic treatment planning stratagem orthodontists had. Tweed received corroboration simultaneously from another former Angle protégé in Australia, Raymond Begg, who had studied aborigines and concluded that nature intended for enamel to wear. He decided that orthodontists could mimic nature by extracting teeth prior to orthodontic therapy. The Tweed and Begg extraction philosophies eventually prevailed and remained uncontested for some time. Several years passed before Holdaway , published his articles that suggested the soft tissue as the determining feature of diagnosis. This disputed Tweed’s narrow diagnostic regimen that focused on the mandibular incisor and totally neglected the soft tissue. Tweed’s triangle set in motion a trend that emphasized more prudence in the extraction of teeth. Soon others added their discoveries regarding soft tissue and the maxillary incisors as main determinants of diagnosis and treatment planning. From the inception of this specialty, with Angle, diagnosis never had too much importance because everyone received the same non-extraction treatment with the same expansive appliance. The marvel of it is all that the collection of orthodontic records never became important. A few months

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ago an orthodontist boasted that since invoking a different treatment regimen, he was treating 98 percent of his patient non-extraction using treatment. One was tempted to ask if he still took records because with diagnostic certainty such as that, records are clearly redundant. Orthodontists should not waste patients’ time and money taking impressions, cephalometric X-rays or doing treatment simulations, if all treatment plans are essentially the same. One does not need orthodontic records to come to such a preconceived conclusion. Obviously, this one-size-fits-all treatment planning did not benefit patients a hundred years ago, and it does not in our own age, but such simplicity continues to hold enormous appeal for many orthodontists. Orthodontists pride themselves in being scientists, and without doubt they receive good training in the scientific method; but it takes very little anecdotal information to eclipse the scientific judgment of many in the profession. Albert Szent-Györgyi was probably more right than he knew when he said, “The brain is not an organ of thinking but an organ of survival like a claw and fang. It is made in such a way so as to make us accept as truth that which is only advantage.” No matter how spectacularly orthodontic therapy changes, it will benefit our patients minimally if we do not have a concomitant improvement in our diagnostic and prognostic knowledge. This remains the number one imperative for those who practice orthodontics. Orthodontists should view any new therapy unaccompanied by equally sophisticated diagnostic knowledge suspiciously. Patients have already received far too much orthodontic treatment but diagnosis. Instrumentation The first attempts to correct malocclusions used simple large arch wires ligated to the malposed teeth. Pierre Fauchard of France developed the precursor of the modern appliance — expansion arch. This arrangement gave only tipping control, in one dimension, and soon proved inadequate for controlling rotations. In 1887 Edward H Angle

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introduced the E arch, i.e. expansion arch that used a labial wire supported by clamp bands on the molar teeth which ligated to the other teeth. Metallurgical developments by the early 20th century allowed clinicians to encase all of the teeth with bands and solder attachments that could control the horizontal rotations. Angle developed a popular attachment known as the pin and tube attachment in 1911, and it satisfied many of the requirements of clinicians; but this demanded unusual dexterity, patience and skill, so dental clinicians evolved to a ribbon-arch bracket, which Angle introduced in 1918. It provided good control in two-dimensions and became popular quickly. The ribbon arch attachment also marked the first time orthodontic attachments gained the name bracket. When Angle launched the ribbon-arch bracket, he had already started work on the edgewise bracket primarily as a supplement to his ribbonarch appliance. Nevertheless, the edgewise bracket did not suddenly spring full-grown from Angle’s fertile mind, but slowly evolved with several iterations. When Angle realized that this bracket could deliver three-dimensional control of the teeth with horizontal, one directional placement and simultaneous engagement of all the teeth, he changed the bracket several times until he achieved it in 1928. It received early and enthusiastic endorsement from dental clinicians throughout the United States and eventually eclipsed other useful orthodontic appliances such as the McCoy open tube appliance, the Atkinson universal appliance and the Johnson twin wire attachment. The universal application and durability of the edgewise bracket confirmed Angle’s immodest claim that it offered the “latest and best in orthodontic mechanisms”. Innovators have added minor but practical trimmings such as rotating wings, twin brackets, different dimensions, preadjusted appliances, lingual applications, etc., but the essence has remained edgewise. For any instrument, particularly in the health sciences, to remain virtually unchanged (and almost as useful for close to a century) approaches unbelievability. In the automobile industry, this would be equivalent to the Model T Ford remaining as the epitome of motoring sophistication.

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Other than adding wings and doubling the bracket to make the popular twin edgewise bracket, Angle’s invention has remained basically unchanged. Holdaway suggested angulations for brackets to help set anchorage, parallel roots and artistically position teeth, while Lee had built some anterior brackets with the ability to torque incisors. But it was Andrews who was to develop an appliance that would apply first, second and third order movements to the teeth without making changes in the wire—hence the Straight Wire Appliance. Preadjusted orthodontic appliances have dominated the profession for the past 30 years, and the belief in them shows little sign of abating, even though many have questioned the one-sizefits-all idea. And back again... The publication of Frankel’s work with functional appliances illustrated significant enlargement of dental arches and reawakened an interest in nonextraction therapy. Nevertheless, Frankel mechanics required the use of removable appliances, and that did not resonate well with many orthodontists or their patients. After a brief flurry of interest in the United States, few clinicians continued to use the Frankel appliance on a regular basis. Nevertheless, the successful use of orthopedic appliances alerted orthodontists to the possibility of increasing arch widths and arch perimeters with minimum forces. Although mandibular canines offer significant resistance to expansion, mandibular premolars and first molars often demonstrate substantial and stable expansion. Brader hinted at this with his work on the trifocal ellipse arch form, but he did not follow through about how this might give wider and more accommodating arch forms. Low-force titanium coil expanders have shown their ability to develop arches laterally, and recently Damon has suggested that low arch wire forces, coupled with a passive tube and a small wire-to-lumen ratio, enable teeth and their accompanying dentoalveoli to expand in all planes of space. Damon feels that using small, low-force wires such as those of Copper Ni-Ti™ (Ormco Corporation, Orange, CA) achieves the ideal biological forces proposed long ago by several investigators.

Self-ligating brackets that essentially form a tube, developed several decades ago with the Ormco Edgelok 26 being the first, closely followed by the speed bracket. Both of these early selfligating systems suffered from the fact that the straight-wire appliance phenomenon debuted at approximately at the same time, plus a lack of appreciation for what the newer titanium wires could achieve. Damon has persisted since 1995 with his version of a self-ligating bracket and has fundamentally changed the types of arch wires and the sequence in which clinicians use them. His experience has shown that with many patients he can often eliminate distalization of molars, extractions (excluding those needed to reduce bimaxillary protrusions) and rapid palatal expansion. He offers compelling clinical evidence of doing this with consistency. The Damon bracket is essentially a tube designed with the right dimensions to foster sliding mechanics where needed and enough play in the system for torque and rotational control using the larger cross section wires. Damon starts cases with a large lumen arch wire slot and 0.014 or smaller diameter hi-technology arch wires. Starting cases with a large dimension passive arch wire slot and small diameter wires diminishes the divergence of the angles of the slots. This lowers the applied force and binding friction. The most logical questions readers could propose would be why has Damon shown successful expansion whereas Angle did not? The quantity of expansion probably differs little, but the quality of expansion offers a quantum change. Mollenhauer has suggested as much with his appeal for light forces. Even though Angle used a ribbon arch, (which suggests a thin, delicate wire) the actual size of the wire had the dimension of 0.036 × 0.022 inches. Ligating to this wire would overwhelm the periodontium and prevent the development of a supporting dentoalveolus. Rather than forming new bone, the supporting dentoalveolus would simply bend and upon completion of treatment quickly return. Astute clinicians often see this with molar distalization from headgear use and over treat such movement in order to compensate for this regressive bone bending.

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Schwartz stated that it takes 20 to 26 g/cm² of force to collapse the capillaries in the Periodontal ligament. With RPEs and headgears, this force sometimes exceeds 10 pounds! Proffit states that optimal force levels for orthodontic tooth movement should be just high enough to stimulate cellular activity without completely occluding blood vessels in the periodontal ligament. True biomechanics is staying in the optimal force zone, i.e. keeping forces below capillary blood pressure. Conventional ties (o-rings and stainless steel ligatures and spring clips) make staying in the optimal force zone nearly impossible due to the increased binding and friction. The most important caveat Damon offers clinicians is not to use their ordinary mechanics with his system, and I could not agree more. When I first began to use the Damon system, I continued to use the regular sequence of arch wires and saw little advantage to these new, more expensive brackets. Nevertheless, as I began to use the brackets according to Dr Damon’s advice, I started seeing phenomenonal changes. The following patient illustrates typical responses to the biomechanics offered by the Damon system. E-ARCH APPLIANCE E-arch appliance was developed by Angle in early 1900. It is also referred to as Edward Angle‘s Earch. It was the first Angle’s orthodontic appliance developed to treat malocclusions. E-arch appliance consists of bands which are placed on molar teeth on either side of the arch of a heavy labial arch wire extended around the arch. The ends of labial extended arch wire threaded to the buccal aspect of the molar bands allowed the arch wire to be advanced so that the arch perimeter increased. Individual teeth were ligated with the heavy labial extended arch wire with ligature wire of 0.010" (Fig. 18.3). PIN AND TUBE APPLIANCE Pin and tube appliance was also developed by Edward H Angle. In this pin and tube appliance, all teeth are banded. Vertical tubes were welded to the bands on the labial surface in the center of the crown for all teeth in the arch. Arch wires were secured with soldered pins that inserted into the vertical tubes (Fig. 18.4). Tooth movement was

Fig. 18.3: E-arch appliances

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History of Orthodontics

Fig. 18.4: Pin and tube appliance

achieved by altering the placement of these pins. Pin and tube appliance is also used for treating malocclusions RIBBON ARCH APPLIANCE Ribbon arch appliance was also developed by Edward H Angle and it is the modification of pin and tube appliance. This appliance was introduced in 1910. Ribbon arch was the first appliance to use a true bracket. The bracket has a vertical slot facing occlusally. The brackets were attached to the bands at the center of labial surface of teeth (Fig. 18.5). EDGEWISE APPLIANCE In order to overcome the deficiencies encountered with his previous techniques, Angle desired a metal bracket that could give a better control over individual tooth movement. The edgewise bracket has a rectangular slot facing labially, rather than occlusally or gingivally, which receives a rectangular arch wire. This unique feature of rectangular arch wire in a rectangular slot enabled control of tooth movement in all three planes of space. Furthermore, the bracket has four wings, two occlusal and two gingival, which increase the

Fig. 18.5: Ribbon arch appliance

surface of arch wire with the bracket slot and thus give accurate control over tooth movement (Fig. 18.6). The term Edgewise refers to the method by which rectangular arch wire is inserted into the horizontal slotted bracket. The edgewise appliance was developed and introduced to orthodontics by Edward H Angle in the year 1925. Every generation of men admires his own wisdom, skill, science, art and progress. In light of today’s progress, it is interesting to know that today orthodontists believe he is doing something heretofore never practiced. Although the practical

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History of Fixed Orthodontic Appliances

Fig. 18.6: Edgewise appliance

growth of orthodontist has occurred during the last hundred years, hardly we find any material progress in this science until within the last half century. Out of the great achievement by mankind in orthodontics the edgewise mechanics was one of the last and greatest contribution of Edward H Angle after a lifetime devoted to the development of the orthodontic appliance. The edgewise appliance reflexes the philosophy of Edward H Angle. This was designed to allow orthodontists to place the teeth into Angle concept of “Lines of Occlusion”. WHAT WAS ORTHODONTICS BEFORE ANGLE SYSTEM? i. Funchard’s bow (1728): The first scientist attempt at tooth movement occurred in 1728 by a French Physician, Pierre Fauchard, made use of a flat strip of metal, pierced with holes

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suitably placed. The flat strip of metal was made in the form of an arch of various crooked teeth were secured to it by threads passing around them and through the holes. The threads were tied for force application. Thus the first Expansion arch was introduced. ii. Dwinelle’s jackscrew (1849): In 1849, Dwinelle invented the regulating Jackscrew. It delivered a pushing force on the teeth. Angle improved the jackscrew by making it more delicate and by increasing the force. He developed later a regulating retracting screw which delivered pulling force on the teeth soldering was introduced at this time to provide for the attachment of the Jackscrew and the retracting screw to bands. iii. Kingsley’s headgear: In 1861, Kingsley introduced the headgear to apply extra-oral force and provide acceptable anchorage. Angle respected Kingsley so much that he incorporated this headgear into his system. iv. Magill’s band: The practice of orthodontics has changed forever in 1870 with an invention that most orthodontist have not seriously associated with treatment. It was the invention of dental cements by Magill which later lead to the development of band which could be attached to tooth. v. Coffin flexible piano wire: In 1861, Coffin introduced flexible piano wire and after 26 years, Angle (1887) developed the prototype of the first bracket attachment a delicate metal tube soldered to the band. These two inventions which took 26 year apart enabled the orthodontist to apply the rotation force on teeth. vi. Bakers (case) rubber elastic: In an article “the use of Indian Rubber in Regulating teeth” (1896) according to him, very light forces generated by the Indian rubber is sufficient for regulating the tooth movement . He used it to provide intermaxillary force of anchorage. EVOLUTION AND DEVELOPMENT OF THE EDGEWISE APPLIANCE To start with, simple basic E-arch which is the first appliance described by Angle in early 1900, is capable of tipping tooth crowns into proper alignment. This is the first appliance to employ stationary anchorage or bodily control of the

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anchor molar teeth. But Dr Angle realized the short comings in this approach and thereafter developed the pin and tube appliance in 1910, by which the tooth roots could be brought into proper axial relationships. But the difficulties encountered with this mechanism involved the high degree of skill necessary to obtain proper parallelism between the tubes and the arch wire and also the necessity to unsolder the pins every time. It was designed to move teeth in different locations on the arch wire and also correction of rotations. The next step in the evolutionary process was the development of the ribbon arch appliance in 1915. The ribbon arch bracket was actually the first bracket as such, to be used in an appliance. It is obvious, therefore this was a great step forward in the development of orthodontic appliances. The chief advantage of the ribbon arch appliance was the fact that rotations were easily accomplished. It is also offered buccolingual and incisogingival movements. Gingivo-incisal and gingivo by occlusal movements are also possible. The main disadvantage was that mesiodistal axial movement was difficult to obtain, second disadvantage is the difficulty in obtaining distal tipping movements of the buccal segments, third the size of ribbon arch itself did not offer the stability thought necessary for stabilization or anchorage of the posterior teeth. Dr Angle’s final achievement was presented shortly before his death. The edgewise appliance was introduced to the dental profession in 1925. The edgewise arch mechanism was designed to allow the orthodontist to place the teeth into Angle’s concept of “Line of occlusion”. The original bracket was designed with slot 0.022 by 0.028 inch. Over the years, many changes and modifications have been made in the basic appliance itself. Gold alloy arch wires were used exclusively in the formative years of the appliance. Although Dr Angle intended the edgewise appliance to be used only for treatment without the removal of teeth, to fit into is concept of the line of occlusion, the mechanical principles of this original thinking were so sound that the basic philosophy is still in use today. It will probably have considerable value in orthodontics for many years to come. Over the years, new principles of force application and control have been evolved by

orthodontists who have conscientiously studied the possibilities and potentials of this appliance. It is interesting to note, that in 1943 Dr Robert Strang made the statement that he was certain that undiscovered possibilities are still to be brought forth, from this device to aid the specialist in difficult corrective procedures. However, it is necessary to constantly bearing mind the basic philosophy and concepts of the edgewise appliance as originally presented by Dr Angle. The basic concepts are still the key success with its use. EVOLUTION OF BRACKET The evolution of edgewise bracket is the study that has to be heard and read and never to be forgotten. This story started in 1916 in the form of ribbon-arch bracket as devised by Dr E H Angle. Although it became very popular at that time the bracket could not mask its deficiencies. Some of the highlighting faults of these brackets were: a. It could not control tooth movement in all three planes. b. Root control was not upto expectations. Hence, Angle decided to modify this bracket and the year 1925 the “edgewise bracket” was born to overcome the deficiencies of the ribbon arch. Angle reoriented the soft from vertical to horizontal and inserted to rectangular wire rotated 90 degrees to the orientation. It had with the ribbon arch, thus the name “edgewise”. The bracket was referred to initially as “open face” or “tie bracket”. The edgewise bracket by Angle was made with soft gold with a 0.022 × 0.028" slot that was readily deformed by the forces of occlusion and by tying ligature wires to the bracket. The original edgewise bracket was redesigned into the cross section that is used today. The original design has been modified to provide a slightly larger bracket and one with greatly increased tying area under the wings; this increased area makes the placement and tying of ligature wires much easy. The brackets are modified in so many ways. For examples, single width bracket, twin bracket, curved base twin bracket, twin bracket tooth rotation, etc. EVOLUTION OF EDGEWISE BUCCAL TUBES The last tooth in the arch that is banded, which is usually a molar, has been commonly referred to

History of Fixed Orthodontic Appliances

as the anchor tooth. A section of tubing instead of some type of edgewise bracket is placed on the buccal surface of the anchor molar and as is called the buccal tube. In edgewise appliance, the original buccal tube was a piece of 0.22 × 0.028" gold or nickel silver tubing soldered to the molar band. The buccal tube is for insertion and stabilization of the arch wire, which is inserted into the tube horizontally and is therefore completely encased in the sheath like structure.

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THE CONCEPT OF THE IDEAL ARCH At an early stage in his development, man recognized in the arch, a strong, stable frame work upon which to build structures. The igloos of the Arctic and the mud huts of the plains are examples of structures employing the keystone and balancing effect of arches and domes. An excellent comparison of the orthodontic arch with other natural arch formations was made some time ago by Dr Mathew Lasher. He noted that the shell of an egg has extreme strength in spot of its delicate structure and that the curved walls and ceilings of caves maintain their integrity for millions of years. Dr Lasher went to compare the architectural arch with the dental arch, a comparison, with slight modification, that is worth reviewing. Comparison of Architectural and Dental Arches To appreciate the concept of the ideal dental arch, it is necessary to describe the basic principles which lead stability to the architectural formation known as the voussoir arch. A series of wedge— shaped units usually made from blocks of stone are arranged to form a structure with a curved outer surface and a curved inner surface. This arch will be self supporting even without and joining material and it is possible to determine the distribution of forces which tend to maintain and support it. The top block [A] is known as the keystone. Block B, resting on the ground itself or the structure upon which the arch rests is called the abutment. Blocks C known as haunches. The curved inner surface is called the intrados and the curved outer surface is called the extrados. The height of the arch is called the rise, and the width is called the span.

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The architect must determine geometrically, the curvature of the arch and the weight is to be maintained, because each unit of an arch is an active, working component tending to maintain its own position and to give support to its adjacent component. There is a central distribution of force between the various blocks that maintain this structure in equilibrium. The same principle applies in a dental arch; consider each of the teeth as supporting structures, each maintaining itself against the pressures transmitted from the adjacent teeth. The line of force resistances which maintains the teeth are properly positioned anatomically or mechanically to produce a balanced arrangement. Therefore, it is imperative that each unit in a dental arch be in a precise anatomical relationship to its neighbors and that each contact relationship be such that forces are distributed through the center of mass of the crown in the horizontal plane. There is arch integrity along a smooth curve, through the center of mass in the mesiodistal plane in the anterior teeth. These may be termed the “haunches” of the arch. The basis of this smooth curve is the cuspids, which may be called the “Springers”. The bicuspids and molars are supports and may be termed the “pillars”. This structure is buttressed or reinforced laterally by the cheek on the outside and the tongue on the inside. Theoretically the dental arch will maintain itself if the bicuspids and molars are not disturbed by lateral force. If such forces are present, then the entire arch may lose its continuity and its integrity will be destroyed. Cause for Collapse of Arches Four basic reasons for failure of arches: 1. Slipping of the voussoirs: The curvature of the arch is either too flat or too pointed and the haunches or side blocks are more in or out because they cannot take the strain, e.g. Irregular arrangement of teeth. 2. Rotation of voussoirs: The line of action or resistance passes to the outer or inner third of the blocks, rather than through the middle, creating a tendency in part of the blocks to rotate in the arch and to cause failure. 3. Crushing: The weight imposed on the arch is greater than the strength of the material to resist.

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4. Failure of the buttresses: If lateral stresses exceed the limits of the additional support, the buttress will fail, and the entire structure will collapse. The similarity of problems of the anatomical arrangement of teeth to those of the architectural arch has been noted for many years. In dental arches, only slipping and rotations will cause the collapse of arches. Slipping is mainly because which irregular arrangement of the teeth and rotations of the teeth occurs when the line of force does not pass through the center of mass of the tooth. Crushing of the voussoir arch, does not occur in the dental arch. Failure of buttresses: The buttressing effect of the cheeks and tongue against bicuspids and molars is demonstrated clearly by the integrity and stability of this area when arch widths are not changed during treatment. Ideal Arch Form A consideration of the causes of failure of the dental arch automatically gives an insight into the primary objectives of orthodontic treatment for maximum stability, it is essential that arch integrity be established of ideal arrangement of the teeth. The teeth should be positioned as indicated by Edward H Angle to conform to the “line of occlusion”. Accepting this it is also necessary to accept the concept of the ideal arch as essential to a well balanced tooth arrangement, that is fundamentally stable and will more likely maintain its integrity, with this objective all arch wires made, and towards it all planned tooth movements are predicted. The variation in dimension and shape of the different teeth in each arch makes their relationship which each of them unique and precise, if arranged in an ideal arch form. Since there is a variation in anatomical dimension in a labiolingual direction of various teeth at the bracket level, it is necessary to consider several anatomical demands that determine the arrangement of teeth in an ideal arch form, the maxillary arch, the central incisor is a thicker tooth than the lateral incisor, and so as the cuspid. Since the maxillary anterior teeth contact the mandibular anterior teeth, it is safe to assume that

the curvature of the lingual surfaces of the maxillary anterior teeth should conform to a continuous smooth arch. This being the case, the labial outline of the maxillary anterior teeth at the brackets will vary according to the differences in thickness of the teeth themselves. The general position of all the maxillary anterior teeth must relate to the labial contour of the mandibular anterior arch. In the mandibular arch, arch wire configuration again is governed by tooth shape and size. The variation of the labial outline will be governed by the dimensions of the individual teeth at bracket level. Consequently, there is a difference between the labial outlines of the maxillary incisal teeth and of the mandibular incisal teeth which relate to the labial contour of the mandibular incisal teeth. In the mandibular arch, the labiolingual dimensions of the four anterior teeth are the same, so that a continous arc is contoured. The smaller labiolingual dimensions of the mandibular canine reduce the effect in this area. In its normal position, the mesiobuccal cusp in the maxillary and mandibular molar is much more prominent than rest of the tooth. Therefore, an offset, or a step out, as it is sometimes called is necessary to make the wire conform to the buccal surface of maxillary and mandibular molars. The general form assumed by the arch wire in each arch, therefore, must be a curve in the anterior section and a general tapering distally, progressively increasing in arch width. THE IDEAL ARCH WIRE The purpose of an ideal arch wire is: to transmit to the brackets through the contour of the wire, the ideal arch form of the teeth, for particular patient. Forming the arch wire: There are different methods of forming an arch wire as well as different techniques for different wires, i. e. gold alloys and stainless steel. Arches are made in one of the three ways. 1. By indirect measurement a. The Angle methods—using graph b. The Bonwill-Hawley method 2. By direct measurement—patient mouth (Chair side) 3. By adaptation: on a plaster, model

History of Fixed Orthodontic Appliances

The ideal arch wire can be made by any one of those three methods, depending upon the understanding and skill of the operator. The “Angle” and “Bonwill-Hawley” methods provide a means of obtaining perfect arch symmetry by intermittent checking during the formation of the arch wire.

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Characteristics of the Ideal Arch Wire An ideal arch wire has certain identifying characteristics. It is flat and without bends in its vertical plane other than the curve of speed. It is bilaterally symmetrical and has the following bends in the horizontal plane. The anterior bend: This is the arch that extends around the labial of the teeth from cuspid to cuspid. The lateral set-back bends: Because of the labiolingual thickness of central and cuspids as compared to the lateral incisors known as the lateral set-back bends. The mesial cuspid bends: The demarcation between the cuspid eminence bends and the lateral set-backs is made at the mesial of the cuspid and is known as the mesial cuspid bend. The buccal sweep: The part of the arch wire that extends distally from the cuspid eminence is not a straight line, but instead it has a slight or gentle curve running from the cuspid to the end of the arch wire. This gentle curve forms an arch that is at least equal to the thickness of the archwire. The molar bayonet bends: The first and second molars usually extend buccally out from the line of the cuspid and bicuspid surfaces due to the buccolingual thickness of those teeth. To compensate, the arch wire is bent abruptly outward by a double bend called the bayonet bend. Arch Wire Bends All bends placed in arch wires during treatment of the various types of malocclusions with the Edgewise arch mechanism may by classified into three general types. 1. Primary or first order bends: Are those bends placed in the arch wire that do not alter the horizontal plane of the wire. Examples: The various bends used to form the ideal arch wire when properly placed, permit the arch wire to lie tangent to a glass slab in its entirety.

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2. Secondary or second order bends : Are also known as tip back bends are bends placed in the arch wire in the vertical plane. They are utilized to tip the teeth in the buccal segments of both dental arches either mesially or distally. In edgewise appliance, three types of second order bends are there; i. Tip back bends ii. V bends iii. Artistic positioning bends i. Tip back bends: Tip back bends for preparing anchorage in edgewise appliance. It is an upward and downward bend. These bends are placed between II bicuspid, first molar, and in between I molar and II molar. The degree of tip back in the terminal molar is such that, when the arch wire is placed in the buccal tubes, it will cross the cuspid teeth at the dentoenamel junction. The arch wire when raised and ligated to the two brackets on the first molars are depressed. At this point, the arch wire will lie gingival to the brackets of the second premolar teeth. ii. V bend: These V bends are placed between the lateral and cuspid teeth. The apex of the V is pointed gingival. Significance: It separates anterior segment and posterior segment. It differentiates torque in anterior and posterior segment. iii. Artistic positioning bends: Are important for the finishing phase of treatment. These bends are necessary because the long axis of each tooth is inclined relative to the plane of a continuous arch wire. Without adequate artistic positioning bends, the incisor teeth are positioned straight up and down with the roots too close together producing an effect sometimes disparagingly called “orthodontic look”. 3. Tertiary or third order bends: Better known as torque are placed in the arch wire to effect buccolingual or labiolingual root and crown movements in single teeth or groups of teeth. Torque is a twist in the wire in the horizontal plane. In upper anterior teeth the torque value in positive means palatal root torque or labial crown torque and in upper/lower in posterior teeth torque given in negative is buccal root torque.

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ADVANTAGES AND DISADVANTAGES OF EDGEWISE APPLIANCE The edgewise appliance was invented by Angle and introduced to the dental profession in 1925. It was then far the advance of any other appliance in the control that it give the orthodontist over the movement of the teeth, and it has never lost that position. From mechanical viewpoint, the best appliance would be one that offers the most complete control of the teeth in all three planes of space with the least amount of material. Edgewise is an exacting appliance, requiring thorough understanding and skill in its manipulation. It is a labial arch technique offering excellent control in the labiolingual, mesiodistal and vertical directions. It is possible with one rectangular arch wore to move teeth in three planes of space. Other appliances may be able to achieve a comparable degree of control, but not without auxillary attachments to the main arch wire. 1. The ability to obtain tooth movements in all three planes of space with a single arch wire. This is true for all the teeth in both arches. 2. The philosophy of treating to an ideal arch or the Angle’s concept of the line of occlusion. 3. The use of rectangular or square edgewise arches which, if properly used; control arch widths, arch form, buccolingual crown inclinations, axial root inclinations and incisor crown and torque. Disadvantages 1. Operator skill is required. Bends incorporated in the arch wire should be accurate to get proper finishing of the case. 2. Heavy forces generated: Causes pain discomfort to the patients, damage to tooth roots. 3. Anchorage control or extraoral anchorage: Edgewise mechanism was designed to achieve universal tooth movements. But the forces delivered by it are much too high. These excessive forces limit its tooth moving efficiency because, high forces prevent tooth movements from being kept under control. When force is applied with the edgewise mechanism, there is movement of the anchor teeth as well as of the teeth which are to be moved. 4. More chair side time.

5. Tipping of tooth crown is impossible with rectangular wires. It is most important in certain stage of the treatment of almost every patient, to produce no tooth movement other than tipping of tooth crowns. For example, bidentoalveolar potrusion. 6. Patient cooperation: Heavy forces cause pain, as well as for anchorage using headgears. 7. Anterior movement of dental arches: It has been found that, soon after edgewise arch wires are fully engaged in tie brackets on all or most of the teeth their is in most patients, some anterior movements of the dental arches as a whole. The explanation for this anterior movement is that the sum of the forces exerted by the arch wires and transmitted through the tie brackets to the roots of teeth is to produce an anterior thrust on the dental arches. It is because tie brackets have a significant mesiodistal dimension arch wires exert force mesially or distally on tooth roots when engaged in the brackets. BUILDING TREATMENT INTO THE EDGEWISE APPLIANCE There are several basic principles of appliance construction that have been referred to as building treatment into the appliance in this instances is defined as the basic components that are cemented to the teeth—the bends with their respective attachments. The shape and manipulation of arch wire and auxiliaries are directly related to the basic appliance that is fixed upon the teeth. Many of the adjustments and tooth movements that require highly complicated arch wire bends can be produced without these time consuming adjustments, if some of the treatment is built into the appliance, by placing the brackets and tubes in such a position that they become unnecessary. The following principles will result in more consistent results with far less effort. The time spent in incorporation of these details into the basic appliance construction will pay large dividends. Bracket angulations: Angle described how edgewise brackets were soldered to band stripes, with the bracket slot parallel to the band strip, at the same time, he suggested angulated posterior brackets to produce desired tooth movements. The general rule in the earlier days of the edgewise appliance was to place the band strip on the teeth

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with the brackets parallel to the long axis of the teeth. In 1941, Tweed pointed out the short comings of this approach. He advocated arch wire bends to obtain correct axial inclinations and called them “artistic positioning” bends. In 1952, a classic article by Holdaway described three uses for bracket angulation. 1. As an aid in paralleling roots adjacent to extraction spaces. 2. As a method of sitting up posterior anchorage units into tipped back or anchorage prepared positions. 3. As a means of obtaining correct axial inclinations or artistic positioning.

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Torqued Bracket Slot In the original and basic edgewise bracket, the slot is cut at a right angle to the base. The rectangular arch wire must be twisted or torqued to obtain correct crown root inclinations. At the suggestion of “Ivan Lee”, manufacturers began to offer brackets with torqued slots. These brackets introduced in the later 1950s or early 1960s, were designed to eliminate the need for adding torque to the anterior portion of the upper archwire. Jarabak described the use of torque brackets in 1960s that had a raised base of approximately 0.016". This projected the bottom of his bracket slot further from the labial surface and eliminated the need for lateral offset bends. Angulated buccal tubes and brackets in the 1960 have to build the correct rotation into the appliance. In addition, during this period at least one of the manufacturers introduced a biangulated tube that incorporated 10 degree of torque as well as rotational control for the upper molars.

think of solution and he came up with the light wire differential force technique, now popular by the name Begg technique. He modified the ribbon arch bracket with a vertical slot facing gingivally. Although biocompatible, the gold arch wire was expensive and forces were insufficient. In search of an alternative, Begg approached his friend AJ Willcock, who was a metallurgist. Willcock developed Australian austenitic arch wires, which were biocompatible, flexible, formeable, malleable, resilient and also inexpensive. Begg technique advocates the use of differential force and tipping of teeth crowns rather than bodily movement. Roots are torqued at the end of the treatment. Although a number of other advanced fixed techniques have been developed lately, Begg technique is still used in many parts of the world. Begg appliance/technique uses stainless steel

Fig. 18.7: Begg appliance

BEGG APPLIANCE The Begg appliance (Fig. 18.7) was introduced by Dr PR Begg (Fig. 18.8) in the year 1930.Begg studied in Angle‘s school of orthodontics and later began practicing in Australia. After a couple of years of practice neither his patients nor himself were satisfied with the treatment using appliances available then, namely ribbon arch and pin and tube appliance. The treatment period was too long, oral hygiene was a prime issue and soft tissue irritation and oral ulcers due to extensive metallic design were common. These problems led him to

Fig. 18.8: Dr.P R Beg

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arch wires along with a number of auxiliaries and springs to achieve the desired tooth movement. STRAIGHT WIRE APPLIANCE Straight wire appliance/technique (Fig. 18.9) is a modification of edgewise appliance and it was developed by Lawrence F Andrew in the year 1970, based on his six keys to normal occlusion. Brackets used in this technique are having prebuilt tip, angulations and torque.

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Introduction (Straight Wire Appliance) Prior to 1970, the Begg’s and Edgewise appliance were the most commonly used appliances in orthodontics. These appliances served the profession well for many years and quality results were achieved by those, who devoted the time and effort to learn, their proper use. In the 1950s, both Begg’s and edgewise practitioners, began to seriously consider ways to achieve, the same or even higher quality results with less wire bending time and more simplified mechanics. The results of this effort was the development of the concept of ideal gnathologic or pre-angulated orthodontic appliance. Such an appliance was envisioned as follows. If an ideal gnathologic set up was completed on study models of a given patient, the pre-adjusted appliance would; 1. Have bracket bases that accurately fit each tooth at a predetermined point 2. Have bracket slots that are passively a “straight wire” coordinated to the patient’s arch form.

Fig. 18.9: Straight wire appliance

The Straight Wire Appliance Origins: Since its introduction in 1971, the straight wire appliance has become widely appreciated by orthodontists. It was designed by “Lawrence Andrews”, an orthodontist practicing in San Diego, California. To assist in establishing a definition of ideal occlusion, a study of excellent untreated occlusions was undertaken and a remarkable collection of more than 120 sets of study models amassed. From examination of the records of these “non-orthodontic normals” Andrews arrived at his six keys of normal occlusion and, with this clear goal in mind, set about designing an appliance to facilitate attainment of his treatment objectives. ANDREWS SIX KEYS TO OPTIMAL OCCLUSION The following terms are necessary for discussing the six keys. 1. Andrews plane: The surface or plane on which the mid-transverse plane of every crown in an arch will fall when the teeth are optimally positioned. 2. Clinical crown: Normally, the amount of crown that can be seen intraoral, Orban has defined the clinical crown as the anatomical crown height minus 1.8 mm. 3. Facial axis of the clinical crown (FACC): For all teeth except molars, the most prominent portion of the central lobe on each crown’s facial surfaces. For molars, the buccal groove that separates the two large facial cusps. 4. Facial axis point (FA point): The point on the facial axis that separates the gingival half of the clinical crown from the occlusal half. Tooth type: A subordinate category within a class of teeth. I molar, II molar. 5. Crown angulations: The angle formed by the facial axis of the clinical crown {FACC} and a line perpendicular to the occlusal plane. Crown angulation is considered positive when the occlusal portion of the crown, tangent line, or FACC is facial to its gingival portion, negative when distal. 6. Crown inclination: The angle between a line perpendicular to the occlusal plane and a line that is parallel and tangential to the FACC at its midpoint (the FA point). Crown inclination is determined from the mesial or distal perspective. Crown inclination is considered positive if the occlusal portion of the crown,

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tangent line, or FACC is facial to its gingival portion, negative to lingual. Key I : Interarch Relationships: Key I patients to the occlusion and the interarch relationships of the teeth. This key consists of seven parts: • The mesiobuccal cusp of the permanent maxillary first molar occludes in the groove between the mesial and middle buccal cusps of the permanent mandibular first molar. • The distal marginal ridge of the maxillary first molar occludes with the mesial marginal ridge of the mandibular second molar. • The buccal cusps of the maxillary first molar occlude in the central fossa of the mandibular second molar. • The buccal cusps of the maxillary premolars have a cusp embrasure relationship with the mandibular premolars. • The lingual cusps of the maxillary premolars have a cusp fossa relationship with the mandibular premolars. • The maxillary canine has a cusp-embrasure relationship with the mandibular canine and first premolar. The tip of its cusp is slightly mesial to the embrasure. • The maxillary incisor overlaps the mandibular incisors and the midlines of the arches match. Key II: Crown angulations: Essentially all crowns in the sample have a positive angulation. Key III: Crown inclination: • Most maxillary incisors have a positive inclination, mandibular incisors have negative inclination. • Canines and premolars are negative inclination. I and II molars have more negative inclination. Key IV: Rotations: The fourth key to optimal occlusion is an absence of tooth rotations. Key V: Tight contacts: Contact points should about unless a discrepancy exits in mesiodistal crown diameter. Key VI: Curve of spee: The depth of the curve of spee ranges from a flat plane to a slightly concave surface. Additional Keys Key VII: Intercuspal position: Intercuspal position and retruded jaw relation should be coincident.

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Key VIII: Anterior guidance: In mandibular protrusion, opening should be guided by the incisors. There should be disocclusion of all other teeth. Key IX: Canine guidance: Lateral movements of the mandible should guided by the working side canines. There should be disocclusion of all other teeth on both working and non-working sides. Key X: Cusp embrasure contact: The intercuspal position should be even throughout both buccal segments. Historical Background Until the mid 1970s, most fixed appliance therapy was carried out using the standard edgewise bracket, either in single or twin form, having a 90o bracket base and bracket slot angulations. Arch wire bending by the orthodontist was required in order to achieve adequate results. Two major disadvantages resulted from this treatment method: Arch wire bends were time consuming and tedious. Even in the hands of experienced operator, adjustments were imprecise and hard work requiring hours of additional chairside attention. The short comings of the bracket system and the extreme skill required of the orthodontist, resulted in many undertreated cases which led to the second disadvantage. Molars were not in a true class I relationship, lacked torque. In effect the resulting occlusion, had the appearance of a “nice orthodontic result” rather than a pleasing natural dentition. Equally important, the long-term stability of tooth alignment was compromised by failing to establish ideal tooth relationships. The Straight Wire Appliance Prior to the 1970s, there were minor appliance adjustments made in the direction of preadjusted appliances (i.e. tipping of the brackets to minimize the need for II order bends), but it was not until Lawerence F Andrews evaluation and measurement of the non-orthodontic normal study models, followed by his development of the Andrews’ straight wire appliance that the preadjusted appliance became a sophisticated three-dimensional system commercially available to the orthodontist. It was hailed by clinicians as a radical step forward offering the dual advantage of less wire bending, coupled with an improved quality of

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History of Orthodontics

finished cases. For the first time, a system second to offer an escape from the drudgery of wire bending. If the finished stage of treatment was less taxing on the patient and orthodontist then perhaps, the quality of the completed case would be greatly enhanced. The old mechanics and heavy force levels were developed for standard edgewise brackets. Simply did not transfer to the new sophisticated bracket system. Operators found that many unwanted changes occurred early in treatment in response to the heavy forces in particular. A “Roller coaster” effect was frequently observed, with rapid, undesirable deepening of the bite. Another frequent observation was in the area of the premolars and canines which tended to tip and rotate into the extraction sites. Such unwanted tooth movement retarded treatment to such a great extent, that the theoretical advantage offered by the new system was dramatically compromised. The Late 1970s There was two possible ways to proceed. The route taken by Andrews (and later by Roth) was to maintain the same force levels and treatment mechanics, but introduce features into the bracket system to prevent undesirable changes. Hence extra torque was introduced into incisor brackets and anti-tip and anti-rotation features were added to canine, premolar and molar brackets. There was the extraction of translation series of brackets, some of which were alter grouped together to produce the definitive Roth appliance. Today the straight wire concept has been modified by Roth, Ricketts and Alexander. The advantages of straight wire appliance include: 1. Precise control of premolar and molar torque. 2. Bilateral symmetry of buccolingual inclination. 3. Bilateral symmetry of arch form. 4. Use of straight arch wires with few or no bends. This reduces chairside time. In addition, the results are not compromised due to clinicians wire bending limitations. 5. Precise control of finishing in both areas in all three planes of space. 6. Elastic use is very minimal and confined to last stage of treatment.

7. Self limitations of movement. Hence, even if the patient misses one or two appointments nothing untoward can happen. 8. Finishing is excellent, not only is the esthetics enhanced but it is possible to produce mutually protected occlusion. The stability of result is thereby guaranteed. LIMITATIONS OF STRAIGHT WIRE APPLIANCE (SWA) It is wrong to assume that no wire bending at all is necessary with Single wire appliance (SWA). While no bending is necessary in the initial stages of treatment, finishing required some wire bending in almost every case. First, because the appliance prescriptions are based on averages, they cannot possibly account for all the variations of tooth size and shape. This means that detailing bends would be needed in finishing wires of some patients. Second, bracket placement is such an exacting requirement of preadjusted appliance that when brackets are not properly positioned, they must be repositioned or compensatory bends must be made. Wire bending may be necessary for over correction. Other criticism that have been leveled against the SWA include: 1. The higher forces that may be needed 2. Torque values 3. Attempt to confirm each patient arch to the same basic arch form. Not withstanding these limitations, the SWA is a significant step forward in rendering “Quality orthodontic treatment and has come to stay at the end of the treatment, a stage of finishing and detailing is required. Rectangular finishing arch wires must incorporate a complex series of adjustments to compensate for labiolingual crown position (first order bends) mesiodistal root position or tip (second-order bends) and labiolingual root position or torque (third order bends)”. Straight wire attachments incorporate individual adjustments for each tooth, the thickness of the base of each bracket and tube varies so that ideal alignment can be obtained from a simplified arch form, omitting the inset and offset bends required with traditional edgewise appliance. The angle at which the arch wire intersects the long axis of the labial faces of the

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History of Fixed Orthodontic Appliances

teeth is also predetermined in such a way so as to build in the optimum tip for each tooth. Finally the angle at which the slot is set into the attachment is adjusted to provide the ideal torque.

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LINGUAL TECHNIQUE Since the earliest fixed lingual orthodontic appliances appeared in the mid to late 1970s, they have been subject to significant vicissitudes. Beginning in 1979, an initial wave of popularity occurred when the first mass-manufactured lingual brackets were released in the United States. At that time, the media and public had been made aware, rather suddenly, of a new technique that would allow straightening of teeth, without the requirement for traditional labial “outside braces”. No matter how vigorously esthetic labial brackets (e.g. plastic, polycarbonate, vinyl and ceramic brackets) or other moderately effective alternatives (e.g. Invisalign [Align Technology Inc., Santa Clara Calif.]) have been promoted over the years, many adults do not seek orthodontic treatment because of the perceived embarrassment of wearing braces. The earliest consistently documented work on lingual appliances began around 1975, when 2 orthodontists working independently in Japan and the United States started developing their own systems to place braces on the inside surfaces of the teeth. The early prototypes were based on modified, traditional “outside” braces. Much credit has been given to late Dr Craven Kurz of California, who with co-workers developed the early Kurz/Ormco lingual bracket system. However, over the same period, significant development was made by Professor Kinya Fujita, of Kanagawa Dental University in Japan, who continues to make great advances in this clinical discipline.

associated with potential back pain and related discomfort may have discouraged many operators— although these difficulties were overcome with practice and enhanced efficiency of clinical technique — resulting in the abandonment of many early lingual orthodontic treatments, which were completed with labial appliances. An early generation of frustrated clinicians came to believe that accurate, efficient lingual orthodontic treatment was an inherent paradox — much like earlier views that, achieving manned flight was impossible. Many negative perspectives continue to be propagated, particularly in North America. Thus, much of the long-term development of lingual orthodontic therapy has occurred in other parts of the world, including Japan, Italy, France, Korea, Germany, Singapore and Australia, Turkey, Israel and South Africa, although there are a few dedicated practitioners in the United States. The lingual technique (Fig. 18.10) was introduced by Craven kurz in 1976. Dr Craven kurz,

Why Lingual Orthodontics Developed Slowly in North America Clinical protocols had not been fully elucidated in those early days, resulting in many clinicians feeling impelled to begin lingual orthodontic cases without being fully prepared. Orthodontists found that the new lingual technique required much more rigorous attention in detail, as well as a fundamentally different approach to treatment planning and biomechanics. Postural challenges

Fig. 18.10: Lingual technique

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History of Orthodontics

an assistant professor at UCLA school of dentistry, realized that many of his patients were adults. This led to the development of the concept of the lingually bonded appliance, consisting of plastic Lee Fisher brackets bonded to the lingual aspect of the anterior dentition and metal brackets bonded to the lingual aspect of the posterior dentition. The plastic brackets were used for the inherent ease of recontouring and reshaping them to avoid direct contact with the opposing teeth. Dr Fujita of Japan published cases treated with his modification of the Begg light wire appliance. He had bonded the Begg brackets lingually or palatally and used the same AJ Willcock Australian austenitic arch wires contoured to the lingual aspect of the teeth. He explained the arch form which resembled a mushroom (when viewed occlusally) and advocated the same basic steps as in the conventional Begg technique to be used with the Begg brackets with a modified base. The 1970s was an exciting decade for orthodontics. The straight wire appliance was developed, treatment demands had increased, and adults were seeking treatment in greater numbers. This increasing demand for adult treatment brought unique concerns to the profession. Esthetics was then and continues to be a primary concern of patients. Adult patients present with unique challenge, of wanting to look good even during orthodontic treatment. They have demands of their work and broader social needs to consider. They think that braces are normally meant for kids. In an effort to provide solution to these esthetic problems, tooth colored brackets and wires were also introduced. But these brackets were invisible only from a distance and staining of the bracket and the tooth presented a significant problem. The search for improved esthetic alternatives to metal or clear brackets continued. Some orthodontists thought of placing braces on the lingual side, leaving the labial surface retouched. During the evolution of lingual appliance therapy, the technique has moved in and out of public and professional favor. Over the years, the appliances and techniques have improved dramatically and as a result, a reliable system has emerged. Research has shown that physically attractive people achieve higher levels of success in many

aspects of life than unattractive people. Improvement in one’s physical appearance, as is common with orthodontic treatment, can positively affect social and professional interactions. The use of unattractive labial orthodontic practice can negatively affect one’s self-esteem. Many patients, if given the choice, would opt for an appliance that was not visible, provided the course and treatment and quality of results were the same as with a conventional treatment. Thus was born the methodology of lingual orthodontics. Even before the development of true lingual appliance, the orthodontic company Ormco in conjunction with Dr Wildman, had attempted to develop a system to align the dentition using the lingual approach. This system consisted of a pedicle positioner, rather than a multibracketed system. Although innovative, the inherent limitations of this system prevented it from gaining widespread popularity in orthodontic community. It was only in early 1970s that Dr Craven Kurz, an assistant professor at UCLA school of dentistry, realized that a major portion of his private orthodontic practice was dominated by adult patients. Dr Kurz developed the first true lingual appliance, consisting of plastic Lee Fisher brackets bonded to lingual aspect of the anterior dentition and metal brackets bonded to lingual aspect of posterior dentition. The plastic brackets were used for the inherent case of recontouring and reshaping them to avoid direct contact with opposing teeth. Around the same time Dr K Fujita of Japan published cases treated with his modification of the Begg light wire appliance. He had bonded the Begg bracket lingually and used the same Australian A J Wilcock wire contoured to lingual aspect of teeth. He explained the arch form which resembled a mushroom and advocated the same basic steps as in conventional Begg technique to be used with Begg bracket with modified base. Further, research was carried out by individuals and group of individuals associated together, with financial finding from orthodontic manufacturing companies. The lingual task force was setup by Ormco to develop a commercially viable lingual appliance. The lingual task force pioneers Dr Kurz, Gorman and Smith were the first to conduct courses on the edgewise lingual appliance, Dr

History of Fixed Orthodontic Appliances

Vince Kelly of Oklahoma and Dr Steve Paige of Florida were the first to start giving courses using Begg appliance lingually. Dr Dilier Fillon of France is the only orthodontist to have restricted his practice to lingual orthodontics exclusively. Some of the drawbacks encountered during the development of lingual orthodontics were : 1. Tissue irritation and speech difficulty 2. Gingival improvement 3. Occlusal interference 4. Appliance control 5. Base pad adaptation 6. Appliance placement and bonding 7. Appliance prescription 8. Wire placement. For Personal Use Only Library Of School Of Dentistry.Tums

Generation 1 1976

Generation 2 1980 Generation 3 1981

Generation 4 1982–84 Generation 5 1985–86

Generation 6 1987–90

Generation 7 1990– Present

Flat maxillary occlusal bite plane from C-C the lower incisor and PM bracket were low profile and half round. No hooks. Hooks were added to canine brackets. Hooks added to all anterior and PM brackets the first molar had a bracket with internal hook. Addition of low profile anterior inclined plane, hooks optional. Anterior inclined plane because pronounced, increase in labial torque in maxillary anterior region TPA attachment. Inclined plane because more square in shape. Hooks on anteriors and premolars were elongated. Hooks on all brackets. Maxillary anterior inclined plane is now heart-shaped with short hooks. The lower anterior brackets have larger inclined plane with short hooks. The premolars brackets were widened mesiodistally and hooks were shortened, the

185 increased width of PM bracket allows better angulation and rotation control.

9. Ligation. 10. Attachment. Modifications were done from time to time to correct these drawbacks :

Drawbacks of Lingual 1. Discomfort to the tongue. 2. Difficulty in speech, which usually improves after two to three weeks of appliance placement. 3. Extended chairside time needed for appliance placement and adjustments. 4. Expensive. Advantages • The labial enamel surface of anterior teeth plays an important esthetic role. • In labially placed brackets, the susceptibility of enamel surface to chemical results and plaque accumulation with poor oral hygiene is increased. • Permanent and unsightly decalcification marks can result in labial. • Easy access for routine oral hygiene procedures on the labial surfaces. • Clinical judgment of treatment progress can be enhanced. • Evaluation of individual tooth position can be easily accomplished by having labial surface free of distracting metal or plastic brackets. • Soft tissue responses of the lips and cheeks to treatment can be judged accurately because there is no distortion of shape or irritation caused by labial appliance. Four distinct situations exist where lingual appliances may be more effective than labial appliances because of their unique mechanical characteristics. • Intrusion of anterior teeth • Maxillary arch expansion • Combining mandibular repositioning therapy with orthodontic movements • Distalization of maxillary molars.

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History of Myofunctional Orthodontic Appliances • History of Activator

• History of Herbst Appliances

• History of Frankel Appliance • History of Bionator

• History of Twin-Block Appliance • History of Double Plate

• History of Oral Screen

• History of Tooth Positioner

The term “Functional appliance” means that when the appliance is fully seated in the mouth, the mandible is forced into an eccentric/Nonecentric relation position. Any such mandibular posture causes the musculature to try to move the mandible toward a centric position. This results in force systems being exerted whenever the appliance is mounted on the teeth or soft tissues of the mouth. Although functional appliances have been used throughout the century in Europe and in the last 40 years in the United States, it was not until the late 1960s that scientific data were available to evaluate the empiric rationalization for their clinical effectiveness. This early data consisted of animal experiments demonstrating histologic and radiographic evidence of increased growth of the condylar cartilage when the mandible was held in a forward position. Breitner’s early monkey studies and Alexander Petrovic and coworker’s initial findings and usually rats as models were complemented by later primates and rat studies conducted by number of independent investigators. Petrovic suggested that the unique characteristic of the condylar cartilage, including cell division of the prechondroblast (as opposed to the chondroblast in epiphyseal cartilage of his long bones or cartilage in the synchondroses of the cranial base) make this cartilage more responsive

19

to orthopedic devices. The animal studies of the 1960s and 1970s created enormous enthusiasm in the professional community and played an important role in the rapid acceptance and use of functional appliances in the United States that has been largely ignored up till that time. There were two important considerations that were left unanswered. First, would the increase in overall mandibular length achieved with orthopedic devices placed in growing rats and monkeys also occur in growing children? Second, was the quantitative increase in condylar growth demonstrated at a cellular level enough of an increase to make a relevant clinical difference in humans? In response to these issues, various investigators in the 1970s and 1980s conducted retrospective clinical studies. This was occurring at the same time that many clinicians were embracing functional appliances as the answer of mandibular deficient patient. A number of these retrospective studies demonstrated some average modest increases in mandibular growth (2–4 mm per year) during treatment with functional appliances. Other investigators did not consider the effect of functional appliance on quantities lengthening of the mandible to be clinically significant. In addition, it became clear that there was much greater variability in the mandibular growth response of humans to functional

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History of Myofunctional Orthodontic Appliances

appliance that in the animal models. Also the variability of growth potential in response to orthopedic treatment was much greater for the mandible than for the maxilla. The enthusiasm for functional appliance in the United States during the 1980s considerably moderated in the 1990s in the light of the less impressive results of the retrospective clinical studies complemented by clinical experiences. Although a modest mean increase in mandibular growth may occur for a group of patients being treated with functional appliances, the increase is not predictable because of the great variability in patient’s response. In addition, there still is uncertainty whether discernible mandibular growth acceleration is nearly temporal and does not result in an absolute final gain in mandibular length. In other words, it is possible that the ultimate length of the mandible may not be altered appreciably in spite of accelerated growth during treatment. There still has been no clear demonstration that the observed treatment effects represent true growth stimulation beyond the limit of human growth variation. In spite of the continued controversy around the reliability of gains in mandibular length from functional appliance treatment, there are the effects that contribute to the correction of Class II malocclusion. ACTIVATOR Viggo Andresen(1870–1950) (Fig. 19.1) in 1908 in Denmark designed a loose filling appliance which he first used on his daughter. He made a modified Hawley type of retainer on the maxillary arch to which he added a lower lingual horseshoe shaped flange which helped in positioning the mandible forward. Viggo Andersen removed his daughter’s fixed appliances before she left for her summer vacation, as was customary at the time, and placed a Hawley-type maxillary retainer. On the mandibular teeth, he placed a lingual horseshoe flange that guided the mandible forward about 3 to 4 mm in occlusion. Andresen, a Danish dentist, did not start specializing in orthodontics until 1919. On his daughter’s return, he was surprised to see that nighttime wearing of the appliances had eliminated her Class II malocclusion, and it was stable. Applying this technique to other patients resulted in significant

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Fig. 19.1: Viggo Andersen

sagittal corrections that he could not produce with conventional fixed appliances. The original Andresen activator was a tooth-borne, loosely fitting passive appliance consisting of a block of plastic covering the palate and the teeth of both arches, designed to advance the mandible several millimeters for Class II correction and open the bite 3 to 4 mm. The original design had facets incorporated into the body of the appliance to direct erupting posterior teeth mesially or distally, so, despite the simple design, dental relationships in all 3 planes of space could be changed. In designing an inert appliance that fitted loosely in the mouth and, because of its mobility, transferred muscular stimuli to the teeth, jaws, and supporting structures, Andresen had taken a decisive step in orthodontic treatment. Although he had effectively redesigned Robin’s monobloc to correct Class II Division 1 malocclusions, he declared that he had no knowledge of Robin’s work at the time. Andresen’s novel device was not initially well received. First, removable appliances were not much accepted at that time. Second, the profession was under the influence of

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History of Orthodontics

Martin Schwarz, whose active plate was then a common form of removable not functional appliance. Finally, Andresen advocated extractions, although not necessarily in connection with activator treatment. And, in contrast to Angle’s concept of ideal occlusion that was then prevalent, Andresen advocated a more realistic “individual and functional gnathological optimum”. Thus he was subjected to the same type of ridicule that Tweed endured years later. In 1925, Andresen, then director of the orthodontic department at the University of Oslo, began developing for the government a simple method of treating Norwegian children. He modified his retainer into an orthodontic appliance, using a wax bite to register the mandible in an advanced position. At the university, Karl Häupl (1893–1960) (Fig. 19.2), an Austrian pathologist and periodontist, saw the possibilities of the appliance and became an enthusiastic advocate of what he and Andresen called the “Norwegian system”. Häupl’s theories were inadvertently strengthened by the findings of Oppenheim, who showed the potential tissue damage caused by the heavy orthodontic forces of fixed appliances. At that time,

Fig. 19.2: Karl Häupl

there was no mention of “growth stimulation”. Activator use became so widespread among European practitioners that there was concern that proper diagnosis was being neglected. Unfortunately, reminiscent of Angle’s following, “functional jaw orthopedics became a profession of faith, a religion, beside which no other opinion was tolerated”. Furthermore, Reitan, in his 1952 doctoral thesis, questioned Roux’s hypothesis and demonstrated that no special histologic picture emerged from the use of functional appliances. His findings were supported by later researchers. Andresen and Häupl later collaborated on a textbook (Funktionskieferorthopädie) about their system in 1936. The sixth edition included Leopold Petrik as coauthor. Although Häupl’s complete rejection of fixed appliances led the profession astray for a time, had it not been for his promotional efforts, the activator might have languished in obscurity. The advantages of the activator include: 1. Treatment in the deciduous and early or late mixed dentition is possible and successful, 2. Appointments can be spread out to 2 months or more 3. Tissues are not easily injured 4. The appliance is worn at night only and is acceptable from an esthetic and hygienic standpoint 5. It helps eliminate pressure habits, mouth breathing, and tongue thrusting. Its disadvantages include: 1. Success depends on patient compliance 2. Activators are of little value in marked crowding, so that patients must be selected 3. The appliance does not obtain a good response in older patients 4. Forces on individual teeth cannot be controlled with the same degree of exactness as in fixed appliances. During the time of Viggo Andresen and Häupl the appliances were made of vulcanized rubber, but this gave way to acrylic in the 1950s. Over the year, various modifications have been made to the original design of Andresen’s appliance such as: 1. The bow activator of AM Schwartz 2. Wunderer’s modification 3. The propulsor 4. Cutout or palate free activator

History of Myofunctional Orthodontic Appliances

5. The reduced activator or cybernator of Schmuth 6. Kawetzky modification 7. Herren’s modification of the activator. Most of the modifications of Andresen appliance were based on Andresen’s concepts. There can be advantages to using a simple design in terms of patient cooperation, case of adjustment and freedom from breakages.

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Graber Observed That “Numerous modifications have been made to the Andresen—Häupl monobloc and have been described in texts and periodical contributions by Petrik, Eschler, Hoffer, Grossman and others. These are surprisingly effective at times but generally a simpler design of appliance is performed.” FRANKEL APPLIANCE A more recent innovation in functional appliance design, the functional corrector or functional regulator or Frankel Appliance was designed by Rolf Frankel (Fig. 19.3) in Germany and was introduced to orthodontics in 1966. This appliance was unique in that, it was principally tissue-borne, mostly supported in the vestibule rather than supported by teeth. There are five types of Frankel appliances and are used for management of Angle’s class I, Class II and class III malocclusions and even it is used in bimaxillary protrusion .Types and their indication in specific malocclusion is explained below.

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Types of Frankel Appliance There are five types of Frankel’s Appliances a are as follows: 1. FR-I is further divided into 3 types: FR-I a FR-I b FR-Ic 2. FR-II 3. FR-III 4. FR-IV 5. FR-V Indications of Various Types of Frankel Appliance FR-I a appliance of Frankel: Treating Angle’s class I malocclusion with deep bite. FR-I b appliance of Frankel: Indicated for treating cases of Angle’s class II division 1 malocclusion where the overjet does not exceed 5 mm. FR-I c appliance of Frankel: Indicated for treating cases of the Angle’s class II division I malocclusion where the overjet is more than 7 mm. FR-II appliance of Frankel: Indicated for treating cases of Angle’s class II division 1 malocclusion and class II malocclusion. FR-III appliance of Frankel: Indicated for Angle’s class III malocclusion FR-IV appliance of Frankel: Indicated for treating bimaxillary protrusion and open bite. FR-V appliance of Frankel: It is used with headgear. BIONATOR The Bionator was developed in Germany by Wilhelm Balter in the early 1950s to increase patient’s comfort and facilitate daytime wear to increase the functional use of the appliance. Balter accomplished this by drastically reducing acrylic bulk of the appliance. There are three types of Bionators , 1. Standard bionator 2. Class III or Reverse bionator and 3. Open bite bionator. Standard Bionator

Fig. 19.3: Rolf Frankel

Standard bionator is used for the treatment of class II division 1 malocclusion and Angle’s class I malocclusion having constricted (narrow) dental arch.

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History of Orthodontics

Class III or Reverse Bionator Class III bionator is also known as reverse bionator and is used for the treatment of Angle’s Class III malocclusion caused due to mandibular prognathism. Open Bite Appliance This type of bionator is used in open bite cases. Uses of Bionatar

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1. 2. 3. 4.

Class II malocclusion. Class III malocclusion. Deep bite cases. Open bite cases.

ORAL SCREEN (VESTIBULAR SCREEN) Newell in 1912 introduced oral screen. It is composed of acrylic base material which fits in the buccal/labial vestibule of the mouth. Indications Indications for oral screen includes 1. Oral habits such as a. Thumb sucking or Mouth breathing b. Tongue thrusting c. Lip biting. 2. In cases of mild proclination of maxillary anterior teeth. HERBST APPLIANCE The Herbst bite jumping mechanism was developed by Emil Herbst in the early 1900s.The original banded design of this appliance was introduced at the International Dental Congress in Berlin (Germany) by Herbst in 1905.It was introduced by Pancherz. Pancherz (Fig. 19.4) used a banded Herbst design that involved the • Placement of bands on molar and premolar Maxilla • Bands are connected by copper lingual wire • Bands on lower right first premolar and lower right first premolar Mandible • Bands are connected by a

lower lingual arch wire The Herbst appliance is a fixed functional orthopedic appliance having passive tube and plunger system with the exact length of the tube

Fig. 19.4: Pancherz

determining the amount of anterior mandibular development. The tube is attached to a maxillary posterior root, whereas the plunger is fixed anteriorly to the mandibular dentition and slides through the tube during opening and closing movements. TWIN-BLOCK APPLIANCE Twin-block appliance is a functional jaw orthopedic appliance developed by Scottish orthodontist William Clark in the year 1977. The Twin-block appliance is composed of maxillary and mandibular retainers that fit tightly against the teeth, alveolus, and adjacent supporting structures. Delta clasps are used bilaterally to anchor the maxillary appliance to the first permanent molars and 0.030 inch ball clasps are placed in the interproximal areas anteriorly. The precise clasp configuration depends on the type of deciduous or permanent teeth and number of teeth present at the time of appliance construction. Various designs are available for the lower part of the twin block appliance. The original design advocated by Clark and it consists of a horse shoe of acrylic that extends anteriorly from the mesial of the first permanent molars. The acrylic covers the lingual aspect of the premolar/deciduous molars and the canines and incisors. In this design, delta clasps are used to anchor the appliance to the first premolar/first deciduous molar and ball clasp are present between the canines and lateral incisors, additional ball clasps can be placed between the incisors if

History of Myofunctional Orthodontic Appliances

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appliance retention is thought to be a problem. There should not be any acrylic material touching the lower molars, this allows the lower molar to erupt vertically if the acrylic on the maxillary block is trimmed to increase the vertical dimension. The Twin-block appliance has been shown to produce increase in mandibular length, incisor proclination and variations in lower anterior facial height. The posterior bite blocks of the twin-block appliance can be trimmed to facilitate the eruption of the lower posterior teeth in patient with a deep bite and an accentuated curve of spee. The blocks also can be left untouched to prevent the eruption of the posterior teeth in patients with a tendency toward an anterior open bite. Indications Twin-block appliance most commonly used in the treatment of class II malocclusions. Duration of Treatment Full time wearing of twin block appliance including during eating and the duration of treatment usually is about (9–12) months. Just as Andresen’s discovery of the activator was an accidental outgrowth of his retainer, so was Hans Peter Bimler’s (1916–2003) (Fig. 19.5) Elastischer Gebissformer (elastic bite former) a fortuitous development. As a surgeon treating jaw injuries during World War II, Bimler had devised a maxillary splint for a patient who had lost his left gonial angle. The splint provided a guide into

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which the patient could insert the remainder of his mandible. In so doing, however, the pull of scar tissue led to a slight widening of the maxillary arch. Bimler reasoned that it might be possible to expand the arch by means of crosswise mandibular movements, and the Bimler appliance was born. Bimler also developed, about 1938, the “roentgenphotogramm,” by superimposing a photograph on a head plate, to show the relationship between the skull, the teeth, and the soft tissues something done today by computer. World War II brought European orthodontic progress almost to a standstill. Nevertheless, functional appliances got a boost because precious metals were no longer available for fixed appliances. In Germany, dentists were ordered to specialize in functional jaw orthopedics. Still, the war brought its own brand of progress. After several modifications, the Bimler appliance achieved its final form in 1949. Compared with previous functional appliances, its reduced size made it possible to wear all day, its elasticity allowed muscular movements to translate more effectively to the dentition, and, because the upper and lower parts were connected by a wire, gradual forward positioning of the mandible became possible. Also like Andresen, Bimler was attacked by the functional establishment, in particular Häupl, for his new ideas, but every functional appliance subsequently developed has incorporated at least one of his innovations. THE DOUBLE PLATE A Martin Schwarz (1887–1963) (Fig. 19.6) began his career as an ear, nose, and throat physician but was diverted into dentistry by famed histologist Bernhard Gottlieb. He became director of Kieferorthopaedia, Vienna Polyclinic, and the jaw orthopedics division of the Viennese government in 1939, where he expanded orthodontic service from 100 to more than 3000 patients. In 1956, Schwarz attempted to combine the advantages of the activator and the active plate by constructing separate mandibular and maxillary acrylic. THE TOOTH POSITIONER

Fig. 19.5: Hans Peter Bimler

In 1944, Harold D Kesling (1901–79) (Fig. 19.7) developed the tooth positioner. The technique involved taking impressions of a patient nearing

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History of Orthodontics

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Fig. 19.6: A Martin Schwarz

completion, denuding the plaster of appliances, and resetting the teeth into ideal positions (the “diagnostic setup”). From the new models, a rubber positioner was made that, if worn enough hours, acted as a finishing appliance. It could also

Fig. 19.7: Harold D Kesling

be used as a retainer or a recovery appliance. Later versions were made of other materials, including clear plastic. Out of these innovations developed T(ooth) P(ositioner) Orthodontics (LaPorte, Ind), which now markets them as Pre-Finishers.

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History of Surgical Orthodontics

20

• Hullihen

• Eiselberg and Pehr Gadd

• Mowlem Appliance

• Blair • Brown

• Rosenthal • Kazanjian

• Pionears • Mandibular Procedures

• Bruhn and Linderman Oral and maxillofacial surgical procedures are sometimes necessary to optimize the results of orthodontic treatment. Surgical orthodontics encompasses all those surgical procedures that are carried out as an adjunct to, or in conjunction with orthodontic treatment. These procedures may range from minor surgeries such as tooth extraction to major procedures such as orthognathic surgeries of maxilla and/or mandible. In cases of crowding due to arch length -tooth material discrepancy, it may be necessary to extract some teeth to obtain proper alignment of teeth. Unerupted teeth may require surgical exposure to facilitate bracket placement and their subsequent alignment. Adult patients with narrow maxilla may need surgically assisted rapid maxilla expansion to correct malocclusion in transverse plane. Cases with significant skeletal discrepancies and dentofacial deformities cannot be treated satisfactorily by orthodontic management alone. In such cases, surgical correction by means of orthognathic surgeries of maxilla and mandible may be indicated to obtain optimal occlusal and esthetics results. Adult patients with significant skeletal malocclusion may also benefit from orthognathic surgery in whom, growth modification procedures cannot be carried out.

Children with congenital malformations such as cleft lip and palate often require surgical procedures along with orthodontic treatment for their rehabilitation. In recent times, new approaches have been adapted in orthodontic treatment such as implant placement to gain anchorage and distraction osteogenesis for advancement of maxilla or mandible. Although orthodontic treatment provides a means of correcting maxilla-mandibular skeletal discrepancies, it is limited to actively growing children. In non-growing individuals, surgical intervention has been implemented to circumvent this limitation. The first surgical procedure for the correction of a craniofacial deformity was reported in 1848, at which time Hullihen successfully performed a partial osteoplastic resection of a prognathic mandible. The subapical osteotomy of the anterior mandible was followed by the removal of a wedge-shaped section of bone from each side of the mandibular body. The anterior segment was then setback into the new position. Surgical treatment of mandibular retrognathia, however, was not reported until the 1st decade of the 20th century, when Blair demonstrated the use of a bilateral horizontal ramus osteotomy to advance the mandible.

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History of Orthodontics

Two years later, Babcock suggested a similar osteotomy for mandibular prognathism . Osteotomy of the mandibular corpus has also been advocated for advancement of the retrognathic mandible. According to Limberg, Brown in 1918 and Bruhn and Linderman in 1921 performed a vertical osteotomy of the mandibular body followed by acute advancement of the anterior segment. The ensuing defect usually healed by new bone in growth. However, the amount of advancement with these osteotomies was limited and often associated with instability of bone segment fixation. In an attempt to increase the contact surface area between divided bone segments and provide greater stability of bone fixation, different modifications of mandibular osteotomies were developed. For example, in order to obtain broader contact surfaces, Cryer and Limberg performed C-shaped arcing and L-shaped oblique osteotomies, respectively, concentric with the desired movement of the mandible. Likewise, Eiselberg and Pehr Gadd developed step-like sliding osteotomies for lengthening or widening the mandible. According to Wassmund, in 1927 Rosenthal performed the first mandibular osteodistraction procedure by using an intraoral tooth-borne appliance that was gradually activated over a period of one month. In 1937, Kazanjian also performed mandibular osteodistraction by using gradual incremental traction instead of acute advancement. After performing modified L-shaped osteotomies in the corpus, he attached a wire hook to the symphysis, thereby providing direct skeletal fixation to the bone segment to be distracted. Three days postoperatively, an “over the face” appliance was placed and activated with an elastic band, thereby exerting traction on the chin and gradually pulling the mandibular anterior segment forward. Seventeen days later, the elastic force was removed. Occlusal splints, connected by rigid bars, remained in place for 11 weeks at which time complete consolidation of the jaw had taken place. Kazanjian’s “over the face” appliance for gradual advancement of the mandible. Even though the first distraction osteogenesis procedures applied gradual traction to the bone segments and surrounding soft tissues, this

technique did not gain immediate acceptance. This was primarily due to the lack of control over bone segment manipulation, inadequacy of distraction appliances, and the instability of osseous fixation. Instead, corrective osteotomies remained a principal treatment modality for the management of mandibular deformities, especially after the introduction of the sagittal split osteotomy by Trauner and Obwegeser. Although acute bone segment movements remained the treatment of choice, the adaptation of orthopedic external skeletal fixation to the mandible rekindled interest in osteodistraction. The application of external skeletal fixation for craniofacial fractures was first reported by Haynes, in 1939. Using a number of pins connected to a rigid bar, he applied this technique to a comminuted, compound fracture of the mandible. Based on external skeletal fixators for the lower extremities, two other external mandibular fixation devices were developed in 1941. The Mowlem appliance and the Converse and Waknitz appliance were similarly designed and consisted of three main parts: two pairs of fixation pins with locking plates located on either side of the fracture, and an intervening telescoping fixation bar. Stader, in 1942, further modified the mandibular external fixator by adding doubleplane-joint elements and a threaded rod to connect both pin fixation clamps (Shaar and Kreuz, 1942). Stader’s fixation appliance was the first mandibular device that allowed angular adjustments in two planes as well as anteroposterior incremental compression or distraction. The early 1950s began a period of rapid development in orthognathic surgery. In 1954, Caldwell and Letterman developed a vertical ramus osteotomy technique, which had the advantage of minimizing trauma to the inferior alveolar neurovascular bundle. This method could be used instead of a body ostectomy to correct mandibular excess. Europe then became the center of progress. Pupils of the Vienna School of maxillofacial surgery, Richard Trauner and Hugo Obwegeser (1957), introduced the intraoral bilateral sagittal split ramus osteotomy, allowing corrections in all three planes of space without a need for bone grafting. Even so, it was not until

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History of Surgical Orthodontics

the early to middle 1960s that mandibular surgeries became popular in the United States. Marsh Robinson and SM Moos developed a reliable extraoral procedure for prognathism: the vertical subsigmoid or vertical ramus osetotomy with a bone cut posterior to the inferior dental nerve. Spectacular changes in the midface resulted from the treatment of craniofacial deformities and the orbital areas by Paul Tessier in France during the 1960s and 1970s. Derek Henderson also developed appropriate planning techniques using a combination of photocephalometry and accurate model surgery. He emphasized anticipating softtissue changes. Alveolar surgeries were the next procedures to gain popularity in the United States after being pioneered in Europe. In 1959, Heinz Köle, a student of Obwegeser, introduced subapical dentoalveolar osteotomies in the anterior mandible. In 1960, Obwegeser began performing maxillary surgery and, by 1969, had described many LeFort I osteotomies, marking the beginning of a new era in the correction of dentofacial deformities: before the mid-1960s, maxillary deficiency was typically treated by mandibular surgery. Obwegeser also performed the first total 2-jaw surgery (1970), facilitating the correction of extensive aberrations in a single operation. Advances in mandibular surgery included intraoral vertical oblique osteotomy (for advancement or setback), total mandibular subapical osteotomy, and refinement of lower border osteotomy. Again, Europeans led the way. In 1972, Paul Tessier came to New York to demonstrate the surgeries he had perfected in the 1960s, and it was not until then that American surgeons, concerned as they were about blood supply and total or partial loss of the osteotomized fragment, could be convinced of the possibilities of moving the midface skeleton. In 1974, the European literature featured 104 LeFort I osteotomies that demonstrated remarkable stability and predictability. In the mid-1970s, Bell and Epker started to popularize the procedure, now commonplace in the surgeon’s repertoire. About that time, orthodontists and oral surgeons began to realize that, contrary to current practice, orthodontists, having aligned the separate arches, could better detail the occlusion if the appliances were left inplace during surgery. Improvements in the stiffness of orthodontic wire helped make

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this possible, even after the introduction of bonding. At the same time, training of oral surgeons started to include orthognathic procedures. Until about 1975, the prevailing concept of facial deformities was that they existed only the sagittal plane, but, as diagnosis became more thorough, surgeons acquired a measure of control over the vertical and transverse dimensions. Plating techniques (1983) and screws for the fixation of jaw fragments reduced the risk of relapse and allowed intermaxillary fixation to be dispensed within many patients. By the 1990s, the use of rigid fixation had become routine, increasing precision and patient comfort (eliminating 6 to 8 weeks of wired jaws, liquid diets, inability to brush lingually, and “claustrophobia”). More recently, the use of resorbable bone plates in Helsinki and Groningen reduced the risk of leaving plates permanently in situ or the necessity of a second operation. Other technological improvements have included freezedried bone, bovine bone, and autogenous bone; biodegradable osteosynthesis material; hypotensive general anesthesia (to reduce blood loss); smaller instruments with better intraoral designs; computer-aided treatment planning; and computerized axial tomography scans (3-dimensional reconstruction). PIONEERS Wescott first reported placing mechanical forces on the bones of the maxilla in 1859. He used 2 double clasps separated by a telescopic bar to correct a crossbite in a 15-year-old girl. However, the entire expansion procedure was slow and tedious, lasting several months. A year later, Angell performed a similar procedure with a differentially threaded jackscrew connected to the premolars. Palatal expansion was achieved rapidly in 2 weeks by the separation of the maxillary bones at the midpalatal suture. Goddard, in 1893, further standardized the palatal expansion protocol. He activated the device twice a day for 3 weeks followed by a stabilization period to allow the deposition of “osseous material” in the created gap. Codivilla, who lengthened a femur to correct limb length deficiencies, first reported bone lengthening by DO in 1905. Abbot then reported lengthening the tibia and the fibula in 1927. These early efforts

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were complicated by edema, skin necrosis, infection, and delayed ossification of the expanded bone. MANDIBULAR PROCEDURES

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Osteotomy of the mandibular corpus was also advocated for advancement of the retrognathic mandible. According to Limberg, Brown in 1918 and Bruhn- Linderman in 1921, each performed a vertical osteotomy of the mandibular body followed by acute advancement of the anterior segment. The ensuing defect usually healed by new bone ingrowth. However, the amount of

advancement with these osteotomies was limited and often associated with instability of bone segment fixation. In 1927, Rosenthal performed the first mandibular osteodistraction procedure by using an intraoral tooth-borne appliance that was gradually activated over a month. In 1937, Kazanjian also performed mandibular osteodistraction using gradual incremental traction instead of acute advancement. After performing modified L-shaped osteotomies in the corpus, he attached a wire hook to the symphysis, thereby providing direct skeletal fixation to the bone segment to be distracted.

History of Cleft Lip and Cleft Palate

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• Demographic Data • Embryological Aspects • Classification of Cleft Lip and Palate

21

• Etiology of Cleft Lip and Palate

• Lip and Palate Associated Problems • Clinical Features of Cleft Lip and Palate

The history of surgery of cleft lip and palates reaches as far backwards as the pre-christian era to 390 BC when for the first time a cleft lip was closed successfully in China. Although Egyptian and Greek medicines developed to a remarkable degree, no descriptions of cleft operations have survived. In the middle ages operations on cleft lip have been several times described. A successful operation on a cleft palate did however not occur until 1816. This can be explained by the fact that cleft palates were thought to be secondary to syphilis, but also because without anesthetic this operation was extremely painful and difficult. Graefe in 1816 and Roux in 1819 published the first satisfactory results. After the introduction of chloroform cleft surgery made remarkable progress. The development of cleft surgery has been chronologically described and finally the present state of affairs is discussed. Long before dentists held the notion that they could give patients pretty smiles, innovative surgeons were coping with a challenge far more fundamental: how to give certain unfortunate infants new faces. Many children born with cleft palates, unable to nurse, failed to survive because of malnutrition. Others were left to die either because of superstition or because the anomaly was too hideous to contemplate. The term “harelip”, now considered demeaning, is believed to have come from the cleft lip’s resemblance to a

rabbit’s mouth. It was once believed that children with cleft lips were born to women who, when pregnant, were frightened by the devil, who had assumed the shape of a hare. The incidence of cleft lip and palate—the single most common defect affecting orofacial structures is approximately 1 in 1000 births; for cleft palate only, 1 in 200; isolated cleft lips occur in 20% of all clefts. Cosmetic surgery began in the ancient world. The Romans performed simple techniques such as repairing damaged ears. Physicians in ancient India used skin grafts for reconstructive work as early as 800 BC. However, the early history of cleft lip and palate surgery describes only unilateral procedures. The first report of surgical cleft lip repair appears in Chin Annals, involving repair of an apparently congenital cleft in 390 BC. The treatment consisted of cutting and stitching the edges of the cleft together, followed by 100 days of complete bed rest, when the patient could eat only thin gruel and was not allowed to smile or talk. Hippocrates (400 BC) and Galen (150 AD) mentioned cleft lips, but not cleft palates, in their writings. The first exact description in the western world of cleft lip surgery was given by Johan Yperman, who practiced in the 14th century. He performed a 2-layer operation with waxed, twisted thread. In 1552, Houlier proposed suturing palatal clefts; 12 years later, Ambroise Paré

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History of Orthodontics

illustrated obturators for palatal perforations. For centuries, perforations of the palate were considered to be secondary to syphilis, and cleft palate was not recognized as a congenital disorder until 1556, when Pierre Franco, along with Paré, described in detail the principles and techniques of cleft palate surgery. Franco has been called the “father of cleft palate surgery”. Hendrik van Roonhuyze of the Netherlands (1625–1672) advised that a cleft lip should be repaired when the baby was between 3 and 4 months of age, because if done earlier, the results would be unfavorable. James Cook of Warwick (1614–1688) was the first to warn against removal of the pre-maxilla because of the danger of interfering with subsequent growth. Pierre Fauchard, in his book Le Chirurgien Dentiste, described several different obturators to close the cleft palate defect. The first successful closure of a soft palate defect was reported in 1764 by Le Monnier, a French dentist, using sutures along with cautery of the edges (the first palatorrhaphy). In the United States, Matthew Wilson, practicing in the 18th century, was the first to publish an account of a cleft lip surgery. Because of the dangers associated with surgery in any form, especially that involving the head or face, it was not until the 19th and 20th centuries that such surgeries became commonplace. A successful operation on a cleft palate finally occurred in 1816 when C von Graefe published the first satisfactory results (Philbert J Roux, called by many the founder of modern cleft lip and palate surgery, did so in 1819). Von Graefe cauterized the margins before suturing them together. When the wound failed to heal, he freshened the wound margins and fastened them to the cheeks, so that they could not rip out. Roux’s operation is well known because the first patient to undergo this procedure, medical student John Stephenson, wrote a thesis about it to complete his degree in medicine. After the introduction of chloroform, cleft surgery made remarkable progress. In 1820, Jonathan C Warren was probably the first American surgeon to perform reconstructive rhinoplasty and close a palate successfully. In 1828, he performed a successful closure of a soft palate, noting that, after closure, the width of the hard palate cleft also diminished. Thus, Warren became an early pioneer in preoperative orthopedic repositioning of the pre-maxilla. The first plastic surgeon in the United States was John Peter Mettauer. He performed the first cleft palate

operation in 1827 with instruments that he designed himself. In 1828, Johann F Dieffenbach enhanced cleft palate surgery by elevating the hard palatal mucosa to allow closure of the hard palate cleft. He also performed the first closure of both hard and soft palates in 1834. The introduction of general anesthesia in the late 1840s led to great advances in cleft palate surgery. In the 1840s, Simon P Hullihen (1810–1857) advocated surgical repair in infancy before eruption of the dentition and used an adhesive strap from cheek to the other before surgery. In 1861, von Langenbeck was the first to use a mucoperiosteal flap, which was separated from the hard palate. This method is still used in many centers. Norman W Kingsley’s Treatise on Oral Deformities as a Branch of Mechanical Surgery in 1880 was the first recognized work on orthodontic and prosthetic treatment of cleft palates. In the field of cleft lip surgery, Hagedorn was a leading pioneer (1884). He used a quadrangular flap to increase the thickness of the medial part of the lip. The first attempts at bone grafting in patients with clefts were performed by von Eiselberg in 1901 and Lexer in 1908. Drachter in 1914 reported closure of a cleft with tibial bone and periosteum. The 1930s were an important decade for developments in both cleft palate and cleft lip. Blair and Brown (1930) attempted to correct the anterior nares by shifting the tissues toward the midline. Also that year, V Veau, a leading figure in cleft surgery, advised that bilateral cleft lips could be closed in 2 to 3 stages, depending on the width of the gap. His name was perpetuated when he devised a 4-part classification of clefts. Later in the decade, Kilner and Wardill independently developed the “pushback” procedure (in which tissue from the palate is moved back to lengthen it). The first cleft palate clinic in the United States was established in 1939 when Herbert Cooper opened the Lancaster (Pa) Cleft Palate Clinic. Cooper’s recognition of the need for multidisciplinary involvement resulted in the formation of a clinic that had all the necessary dental and surgical specialists in one location. He was also among the first to use cineradiography to evaluate velopharyngeal function. In a patient with a bilateral cleft palate, the surgical closure of the lip is different from that of a unilateral condition because of the position of the pre-maxilla, the short columella, and the absence of the muscles in the prolabium. Surgeons who excised the pre-maxilla to suture the gap in the lip did not realize the

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History of Cleft Lip and Cleft Palate

damage being done to maxillary growth with this operation. Elastic traction to reposition the premaxilla in bilateral cleft lip and palate patients is still being practiced. In 1950, C Kerr McNeil, often called the founder of modern-day, pre-maxillary orthopedic treatment, described the use of acrylic appliances to reposition bony cleft segments, in addition to traction. Also in 1950, TM Graber, in his PhD dissertation, was the first to document a disturbance in facial growth as a result of palatal surgery. His work led to the alteration and staging of surgical procedures. About that time, surgeons in Europe were inserting bone grafts as a primary procedure. In the 1960s, Sheldon W Rosenstein, working with surgeons, introduced the technique of placing a plate in the maxilla of a newborn before surgical lip closure to guide the maxillary segments into proper alignment. After lip closure, the aligned segments helped guide the teeth into better positions and reduced the incidence and severity of cross-bite and segment malalignment. The late 1960s and early 1970s was a period when primary bone grafting and maxillary orthopedics were in vogue, but by the 1970s many who had previously advocated the bone-graft procedure had abandoned it because their results had negative effects on the growth of the maxilla and the midface. Others, including Hugo Obwegeser, recommended the LeFort I osteotomy with secondary bone grafting after development of the adult dentition, especially as an aid to orthodontic and prosthetic reconstruction. Additionally, much discussion has occurred over the role and the timing of pre-surgical appliances. Both the hard palate and the alveolus can be molded with passive molds and active devices, with the shared ultimate goals of facilitating surgical repair and providing an improved long-term outcome in both facial form and palatal function. The word ‘cleft’ literally means a crack, split or a gap. Orofacial clefts are congenital deformities, which manifest at birth. Cleft lip and cleft palate are the most common congenital malformations of the head and neck region. The term cleft lip and cleft palate is commonly used to represent two types of malformation which are embryologically distinct that, is, 1. Cleft lip with or without associated cleft palate (CL ± CP). 2. Isolated cleft palate (CP).

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The term harelip often used to denote cleft lip should be discouraged. Cleft lip and cleft palate exhibit wide range of presentation with varying degrees of severity; from a small notch in the lip vermillion to a complete bilateral cleft of lip and cleft palate. Cleft may occur in isolation or as part of a syndrome. Management of these patients is quite challenging since clefts of lip and palate are usually associated with impaired facial appearance, speech, hearing, mastication, deglutition, dental occlusion and treatment should address these problems. Thus, management of cleft lip and palate requires a multidisciplinary approach with a long term treatment plan and individualized rehabilitation program designed to address the treatment needs have given patient. Malocclusion is usually present and orthodontic therapy with or without corrective jaw surgery is frequently indicated. The defects generally have profound psychosocial implications on the afflicted children and their patents. It is reassuring that, with a team approach, the defects are fairly correctable and need not adversely affect the child’s future. DEMOGRAPHIC DATA Race The reported incidence of clefts of the lip and palate varies from 1 in 500 to 1 in 2500 live births depending on geographic origin, racial and ethnic backgrounds. The incidence of cleft lip and palate is reported to be highest in Asians (Mongoloids 1 in 500), intermediate in Caucasians and least in Negroid populations (1 in 2000 to 2500). • Jones C (2000) estimated the occurrence of oral clefts in UK to be 1 in 700 births. • Fough-Anderson (1956) cited 1 in 665 as incidence of cleft lip and palate in Denmark. • Overall incidence of cleft lip and palate in human appears to be 1:700 live births. Sex Males are more commonly affected by orofacial clefts, than females by a ratio of 3:2. Cleft lip with or without cleft palate is more common in males than in females (2:1),whereas isolated cleft palate is observed to be more common in female.

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Type and Side • Cleft lip with or without cleft palate is more common than isolated cleft palate. • Unilateral clefts are more common as compared to that of bilateral clefts (prealveolar clefts) . • Unilateral clefts account for 75% of all cleft seen, while bilateral clefts account for the remaining 25%. • In cases of unilateral clefts, left side is more commonly affected than the right side. The reason why left side is more frequently involved is unknown.

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Syndromic and Nonsyndromic As stated earlier orofacial clefts can occur alone (nonsyndromic) or as part of syndrome with congenital deformities of other parts of the body (syndromic). Over 300 syndromes are known to be associated with orofacial clefts. However, clefting syndromes are rare and make up only 5 % of all clefts.

Two palatine shelves, which extend from left and right maxillary process towards the midline. ♦ Nasal septum which grows downwards from the frontonasal process along the midline. After the descent of the tongue, the elongated palatine shelves become horizontally oriented and are in close proximity to each other by 8th week. They fuse with each other in the midline and is represented by the median palatine raphe. The palatine shelves also fuse with primary palate and the nasal septum. Incisive foramen is present at the junction of primary and secondary palates. Fusion between palatine shelves and nasal septum proceeds from incisive foramen in a posterior direction ending at uvula; whereas, fusion between the primary palate and anterior borders of the palatine shelves progresses in an anterior direction towards the lip. ♦

Cleft Lip and Palate Formation

An understanding of the embryological development of these structures is essential so as to appreciate the etiology of these clefts. The embryonic development of palate takes place between 6th and 9th weeks of intrauterine life. The entire palate develops from two structures: • Primary palate (premaxilla) and • Secondary palate.

Cleft lip and palate occur when mesenchymal connective tissues from various embryological structures fail to merge with each other. • Cleft lip— Arises from failure of fusion between medial nasal processes and the maxillary process. It can be unilateral or bilateral; and can be extended into the alveolar process (CL + CP). • Cleft palate— Arises from failure of palatine shelves to fuse with each other, or with the nasal septum or with the primary palate.

Primary Palate

CLASSIFICATION

• The primary palate is the triangular shaped part of the palate anterior to the incisive foramen. It is developed from frontonasal process by fusion of two medial nasal processes; primary palate forms the premaxilla which carries the incisor teeth.

There are many classifications of clefts. Few commonly used ones are given below.

EMBRYOLOGICAL ASPECTS

Secondary Palate • The secondary palate gives rise to the hard and soft palate posterior to the incisive foramen. It develops from the fusion of three parts as follows:

I. Embryologic Classification Patients with cleft lip and palate can be divided into two groups which are embryologically distinct. 1. Cleft lip with or without cleft palate (CL ± CP) Include: ♦ Patients with cleft lip and cleft palate (CL + CP) ♦ Patients with cleft lip without cleft palate (CL)

History of Cleft Lip and Cleft Palate

2. Isolated cleft palate (CP) include: Patient with cleft palate alone II. Classification by the International Confederation for Plastic and Reconstructive Surgery (1968) This classification has three main groups. Group 1—Cleft of Anterior Primary Palate

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a. Lip: ♦ Right side ♦ Left side ♦ Both b. Alveolus: ♦ Right side ♦ Left side ♦ Both. Group 2—Clefts of Anterior and Posterior Palate a. Lip: ♦ Right side ♦ Left side ♦ Both b. Alveolus: ♦ Right side ♦ Left side ♦ Both c. Hard palate: ♦ Right side ♦ Left side ♦ Both. Group 3—Clefts of Posterior Secondary Palate a. Hard palate: ♦ Right side ♦ Left side b. Soft palate : Median. III.

Veau’s Classification

This classification is morphological and described as four types of clefts: Group I Clefts of the soft palate only. Group II Clefts of the hard and soft palate extending up to the incisive foramen. Group III Complete unilateral clefts involving the soft palate, hard palate, alveolar ridge and the lip on one side. Group IV Complete bilateral clefts of the soft and hard palate, alveolar ridge and the lip.

IV.

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Kernahan’s Stripped ‘Y’ Classification

Kernahan proposed a symbolic classification of cleft lip and palate deformity using a stripped ‘Y’ having numbered blocks. The incisive foramen is represented symbolically by a small circle with the dividing pointing between the primary and secondary palates. Each right and left limb is divided into three portions representing respectively the lip, alveolus and area between alveolus and incisive foramen. The stem of the Y is similarly divided into three portions representing hard palate and soft palate. Each block represents a specific area of the oral cavity: Block 1 and 4 — lip Block 2 and 5 — alveolus Block 3 and 6 — hard palate anterior to the incisive foramen Block 7 and 8 — hard palate posterior to the incisive foramen Block 9 — soft palate Each individual can be diagrammatically represented by stippling appropriate areas of clefting. In submucous cleft of palate the appropriate section is cross hatched. ETIOLOGY OF CLEFT LIP AND PALATE Despite numerous clinical and experimental investigations, the etiology of cleft lip and palates in humans is still largely unknown palate. In most cleft cases, no single factor can be identified as the cause. Heredity with superimposed environmental factors is considered to be the most probable cause of cleft formation. It is important here to distinguish between two forms of clefts; Non-syndromic clefts with no other related health problem and syndromic clefts associated with other birth disorders or syndromes. Syndromic Cleft Cases In syndromic cases, cleft occurs by monogenic mode of transmission, i.e. by a single mutant gene producing a large effect. Over 300 syndromes have been reported in the literatures which have associated clefts along with other defects. Most of these syndromes are rare. Some of the relatively common syndromes associated with cleft lip and palate are listed in Box 21.1.

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History of Orthodontics

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Velocardiofaial syndrome (velum=palate, cardia = heart, facies = face) is the most common syndrome to exhibit clefts. The features include the following— • Cleft palate • Cardiac defects • Characteristic facial appearance • Learning problems and speech • Feeding problems. Box 21.1: Common syndromes associated with cleft lip and palate • Craniofacial Syndromes • Velocardiofacial syndrome • Apert’s syndrome • Crouzon’s syndrome • Carpenters syndrome • Down syndrome • Encephalocele • Goldenhar syndrome • Hypertelorism • Pfeiffer syndrome • Pierre robin syndrome • Saethre-Chotzen syndrome • Treacher Collins syndrome • Van der Woude’s syndrome

palate is genetic in origin; less than 20% of isolated cleft palates (CP) are genetically determined. Environmental Factors Earlier, heredity was thought be single most important causative factor. However, recent studies have shown that, environmental factors play a significant contributory role at the critical time of embryogenic development when lip and palate shelves are fusing. A number of environmental factors have been suggested as causative factors including: 1. A defective vascular supply to the area involved during critical time of embryonic development. 2. A mechanical disturbance in which, size of the tongue may prevent union of parts. 3. Excessive concentration of circulating substances such as alcohol, certain drugs (antibiotics, steroids, insulin) and toxins. 4. Viral infections. 5. Exposure to radiation. 6. Hypoxia. 7. Vitamin deficiencies and excesses. 8. Stress.

Nonsyndromic Clefts

Risk of Producing a Child with Cleft Deformity

Recent investigations show that both heredity and environmental factors act together in causation of non-syndromic clefts. Such a mode of transmission of a defect/trait caused by interaction of multiple genes and multiple environmental factors is known as multifactorial inheritance.

1. Every parent has approximately a 1 in 700 risk of having a child with a cleft. 2. Parents having a child with a cleft have increased risk of having the 2nd child affected2% to 5%. 3. If more than one person in immediate family has a cleft→ risk rises to 10% to 12%. 4. A parent having a cleft→ has 2% to 5% chance of producing a child with a cleft. 5. If a syndrome is involved, the risk for recurrence within a family can be as high as 50% 6. Maternal age→ increased risk of clefting is observed when age of conceiving is late.

Heredity (Genetic Predisposition) In contrast to syndromic clefts caused by single mutant gene, clefts in non-syndromic patients are caused by multiple genes (polygenic), each producing small effects which together create this condition. Every individual carries some genetic liability for clefting, but there is no cleft formation until the threshold level for expression is reached. When the total genetic liability of an individual reaches a certain level, the threshold for expression is reached and cleft occurs. Genetic basis of cleft lip and palate is significant but not predictable. Studies reveal that, less than 40% of cleft lip with or without cleft

CLINICAL FEATURES Oral clefts commonly affect the upper lip, alveolar ridge and hard and soft palates. • The clefting anterior to the incisive foramen is defined as the cleft of primary palate. • The clefting posterior to the incisive foramen is defined as a cleft of secondary palate.

History of Cleft Lip and Cleft Palate

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• A patient may have clefting of primary palate, secondary palate or both. • The clefts can be complete, i.e. extending the entire distance from the lip to the soft palate or incomplete. • CL ± CP can e unilateral or bilateral; isolated cleft palate occurs in midline. • Severity of CL ± CP may range from a small notch on the edge of the vermilion border to a wide cleft extending into the nasal cavity. • Isolated cleft palate may also present with varying degrees of severity. Mildest form is the bifid uvula. A more severe form is a cleft of the soft palate. A complete cleft palate constitutes a cleft of the hard palate, soft palate and cleft uvula. CLEFT LIP AND PALATE ASSOCIATED PROBLEMS Most patients with cleft lip with cleft palate (CL + CP) and isolated cleft palate (CP) present with a myriad associated problems. 1. Dental problems 2. Occlusal problems (malocclusion and impaired facial aesthetics) 3. Feeding problems 4. Nasal deformity 5. Ear problems 6. Speech difficulties 7. Psychological problems. Dental Problems Cleft involving alveolus often affects the development of primary and permanent teeth and the jaw. The cleft usually extends between the lateral incisor and canine area. Teeth may be congenitally absent in the area of cleft or even supernumerary teeth may also be present. Teeth present near the region of cleft may be morphologically deformed or hypomineralized. Crowding or severe displacement of the teeth near the region is a common finding. The patient with cleft lip and palate shows the following features . • Lateral incisor on the cleft side may be absent. • Presence of supernumerary teeth • Fusion of teeth • Enamel hypoplasia • Multiple missing teeth • Ectopically erupting teeth • Anterior and/or posterior cross bite

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• Periodontal complications • Crowding may be seen • Spacing may be present. Occlusal Problems • Clefts involving alveolus and palate invariably show malocclusion. Patients with clefts especially of the palate, show discrepancies in size, shape and position of their jaws. • Most patients exhibit class III malocclusion with hypoplastic maxilla and relative prognathism of the mandible. • Along with missing teeth or supernumerary teeth, retardation of maxillary growth significantly contributes to the development of malocclusion. Scar contracture following early closure of cleft palate significantly retards the growth and development of maxilla in all three planes of space. Narrow high arch palate with constricted and retruded maxilla is a common finding. Feeding Problems Structural defects of cleft lip and palate prevent negative oral pressure required for effective sucking. Feeding is a major problem in these patients as food and liquids regurgitate through the nose. Thus, breast or bottle feeding by sucking is difficult. However, babies can swallow normally, if they are fed directly toward the hypopharynx. The problem can be overcome through the use of specially designed nipples that are elongated and have bigger opening which extend directly into the hypopharynx. Child may swallow lot of air during swallowing and need frequent burping. Nasal Deformity Patients with cleft lips often exhibit deformities of nasal architecture, especially when the cleft extends into the floor of the nose. Plastic surgery of nose is usually done at later stage and treatment after correction of all clefts and associated problems. Ear Problems Clefts involving soft palate predispose to middle ear infections. This is because the levator and

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tensor veli palatine, the muscles of soft palate are left unattached in case of soft palate clefts. These muscles have their origins near the auditory tube and under normal circumstances allow opening of the auditory tube into the nasopharynx facilitating equilibrium and the pressure. In palatine clefts this function is disrupted, the middle ear becomes a closed space without a drainage mechanism. When tube opening mechanism is impaired, there is greater susceptibility of middle ear infections. Accumulation of serious fluids and then bacteria can lead to serous otitis media. Chronic otitis media causes hearing impairment, that is common in patients with cleft palate.

nasopharynx. This is called valopharyngeal mechanism. (Valo = softpalate). During speech and deglutition, soft palate is elevated towards the posterior pharyngeal wall by contraction of its muscles. Valopharyngeal mechanism cannot function when a soft palate is involved by the cleft. The soft palate cannot elevate to make contact with the pharyngeal wall and this result in escape of air into the nasal cavity producing hyper nasal speech. Hearing impairment may further aggravate the speech problem. Retardation of consonant sounds (i.e. p, b, t, d, k, g) is the most common problem. Speech problem should be addressed at the earliest, and several years of speech therapy may be needed to achieve intelligible speech.

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Speech Difficulties During normal speech, the tongue, lips, lower jaw and soft palate work together in a highly coordinated fashion to produce the sounds. The soft palate is raised during the speech, preventing air from escaping from the nose. The soft palate functions as a valve to control the distribution of escaping air between oropharynx and

Psychosocial Problems Impaired facial aesthetics, hearing and speech problems often produce psychosocial problems in these patients. Support of the family, professional help and social worker are all necessary to the normal well being of these patients.

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History of Malocclusion Indices

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• Index of Orthodontic Treatment Needs

• Index of Complexity, Outcome and Need

• Peer Assessment Rating

• Dental Aesthetic Index

Traditional orthodontic thinking has emphasized the major benefits of orthodontic treatment on: the ‘improvement of physical functions, the prevention of tissue destruction and the correction of aesthetic impairment’. (Standard Dental Advisory Committee, 1973). In times of limited resources, it is important that patients who need treatment should be treated and that, when treatment is undertaken, the malocclusion should be corrected to an appreciable extent. Many studies in the UK and Scandinavia have assessed the success of treatment by recording the various occlusal traits before treatment, and after treatment. British Studies Over recent years, the standard of orthodontic treatment undertaken within the general dental services has given cause for concern. Several reports have suggested that British orthodontic results are not as good as Northern European countries (Cousins, 1973; Shaw, 1983; Haynes, 1979; British Orthodontic Standards Working Party, 1986). A report on child dental health in England and Wales (Todd and Dodd, 1985) found that 30 percent of 15-year-olds who had previously received orthodontic treatment were in need of further treatment. The occlusal index (Summers, 1971) was used by Elderton and Clark, (1983) to

record treatment need in a sample of 256 patients in the Scottish Dental Service, most of the treatment being undertaken with removable appliances. Some reduction was seen in 88 per cent of cases. However, 30 percent of cases were minimally improved or made worse, and in those cases which started with a marked malocclusion only about one-third showed a sizeable improvement. Sixty-five percent of cases falling in the ‘No treatment need’ category at the start of treatment showed a sizeable improvement. Thirty-five percent of cases falling in the ‘no treatment need’ category at the start of treatment showed no improvement and, in fact, 15 percent were made worse. In a further survey of 51 cases with a class II division 1 malocclusion treated with removable appliances (Elderton and Clark 1984), 41 percent of cases finished in the two best categories and substantial improvement was found for one quarter of the whole sample. However, 20 percent of the cases showed no improvement at all. In a study undertaken by the Dental Reference Service in 1984 (DHSS 1986), for 59 percent of the estimate references (852), the dental officer disaggreed substantially or fundamentally with the proposed treatment. In 49 percent of the completed treatments, the dental officer considered the treatment unsatisfactory to a major or fundamental extent.

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During the year 1986—87, 35,800 orthodontic cases treated within the General Dental services were reported as discontinued (14 percent of all non-prior approval cases and 26 percent of priorapproval cases).

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Scandinavian Studies Myrberg and Thilander, (1973) assessed treatment results in 1486 cases. In 60 percent, removable appliances were used, whilst the remainders were treated with fixed appliances. In 54 percent of the cases the result was good and in 1 percent treatment had no effect. However, the criteria for assessing the success of treatment were not stated. Berg, (1979) analyzed 246 consecutively treated cases, the majority having undergone fixed appliance treatment. The author looked at both dental cast and radiographic records. He found that the objectives were only achieved in 43 percent of all cases. Root resorption was present in 14 percent of all cases and overjet was not eliminated in 13 percent of Class II cases. the objectives were not achieved in a substantial percentage of class I, class II, and class III malocclusions. Although all the objectives had not been attained, substantial improvement had been achieved and the author coined the phrase ‘partial success’. In a further study, Berg and Fredlund, (1981) used the Treatment Priority Index, TPI (Grainger, 1967) on 60 cases randomly selected from 329 consecutively treated patients in two private practices. At the end of treatment, 36 cases (60 percent) achieved normal or near normal occlusion. They found the greater reduction in the TPI score resulted from an improvement in overjet. It was suggested that the degree of improvement was more important than the ‘success’ of treatment. Post-retention Survey There have been several investigations involving the prevalence of malocclusions over 20 years of age (Ingervall et al 1978 ; Mohlin, 1982 ; Bernhold and Lindquist, 1981). These studies indicate that the prevalence of malocclusion in men and women is similar to that found in children, although 10 percent of men and 25 percent of women had previously received orthodontic

treatment. Mohlin suggested that the need was still high as much of the orthodontic treatment was provided 20-30 years ago, probably as a compromise owing to limited orthodontic resources, removable appliances having been used in two-thirds of the treatments. The treatments had probably reduced the severity of malocclusions, but had not eliminated them. However, Myrberg and Thilander (1973), have reported mild to severe relapse in 24 percent of orthodontically treated children, 1–5 years after treatment. The long-term stability of orthodontic treatment has been reported for a group of 96 patients treated 12–35 years previously (Sadowsky and Sakols, 1982), the majority of cases having been treated with both upper and lower Edgewise appliances. The authors revealed that 72 percent of cases still had deviations outside the ‘ideal’ range. There was a tendency for overjet and overbite to increase, as well for the development of lower anterior crowding. Other studies have shown that even when optimal treatment results had been achieved, imperfection in alignment and occlusion often developed in the long-term (Water, 1953; Simons and Joondeph, 1973; Little et al 1981, 1988; Udhe et al 1983; Shields et al 1985). The constraints imposed by underlying skeletal discrepancies which could not be changed by orthodontic treatment alone were highlighted in a review of 50 consecutively treated patients with an original overjet of 10–15 mm. As few as 6 percent displayed an overjet within the normal range (less than 4 mm) on follow-up (Nashed and Reynolds, 1989). However, 60 percent of all the patients had their overjets reduced to less than 5 mm as a result of treatment. Some studies have attempted to determine the effectiveness of the orthodontic treatment provision by the hospital orthodontic service, using recently developed occlusal indices as measures of outcome and assessed the influence of operator, treatment methods, and individual departments upon treatment outcome in terms of dento-occlusal change. Pickering and Vig, (1974) in the first application of an index to assess the effectiveness of orthodontic treatment used Summer’s Occlusal Index (Summers, 1971) as an outcome measure to evaluate the effectiveness

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History of Malocclusion Indices

of treatment provided for 351 patients treated in one London hospital. This study revealed that a proportion of patients did not benefit from treatment and that fixed appliances were the most effective treatment method. Berg, (1979) used a criterion based approach to assess a sample of consecutive cases treated in his practice. He found that optimal treatment results were achieved in only 43 percent of cases. In a similar evaluation, Berg and Fredlund, (1981) concluded that 60 percent of a sample of cases collected form two private practices had normal occlusions following treatment. While both investigations produced favorable results, an analysis of 256 completed cases at the Scottish Dental Estimates Board using Summer’s Occlusal Index (Summers, 1971) revealed that treatment change was inadequate and the standard of treatment required improvement (Elderton and Clark, 1984). More recently, Jones (1988), carried out an extensive study using a three- dimensional assessment of occlusal change of 109 patients. He concluded that the overall success of treatment was high. This was influenced by the method of treatment; two arch fixed appliances being more effective than removable appliances. The only large scale study has been carried out by Richmond (1991). He assessed 1210 patients’ records obtained from the Dental Practice Board of England and Wales for orthodontic treatment need and treatment standards with the Index of Orthodontic Treatment Need (Brooke and Shaw, 1989) and the Peer Assessment Rating (Richmond et al 1992) respectively. He concluded that the standard of treatment was poor and many patients did not receive an improvement in occlusion following a course of orthodontic treatment. Again, two arch fixed appliance therapy was the most effective treatment method. There are very few recorded studies dealing with the evaluation of treatment results in large samples or in randomly selected cases. In many published studies, only successful cases are analyzed and the frequency with which the demonstrated results could be achieved is often not considered. However, Myrberg and Thilander (1973) examined 1486 treated cases and graded the treatment results. In their clinical judgment, good results were obtained in 54% of the cases.

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Petterson and Andren (1978) found that the majority of orthodontic patients were satisfied with their treatment results. Although most of the patients had found treatment to be ‘troublesome’ 76 percent would have been willing to go through the same procedure again. About 94 percent would have had their children treated if they had developed a similar malocclusion. Fredlund in 1977 (unpublished material) examined the treatment results in all of the 209 cases he had started in 1973. Berg (1979) examined the treatment results in 264 consecutively treated cases. Both Fredlund and Berg found the reproducibility of criteria such as ‘good’, ‘acceptable‘, etc. to be questionable and they therefore based their observations on whether or not so-called ‘text-book’ normal occlusion had been achieved. The results of the two independent studies were similar : text-book normal occlusion was achieved in less than 50 percent of the cases. While many practitioners are convinced that orthodontic treatment influences the soft tissue profile, controversy remains concerning the precise soft tissue response to changes in tooth position. A positive correlation between incisor movement and soft tissue changes has been reported (Roos, 1977). On the other hand, the studies of Angelle (1973) and Hershey (1972) showed that changes in tooth position are not systematically followed by proportional soft tissue profile changes. Variables such as lip morphology, type of treatment (extraction versus non extraction therapy, choice of extraction), patient gender, and age have been held responsible for individual differences in soft tissue response (Wisth, 1972, 1974). Extraction decisions have to be made not only by considering the among of crowding but also the eventual influence of orthodontic tooth displacement on the soft tissue surface of the face. No information concerning the correlation between the initial among of crowding and the changes in profile during orthodontic treatment was found in the literature. In nonextraction therapy without extraoral traction, one can assume that tooth alignment protrudes the anterior teeth and the facial profile. In extraction therapy, tooth alignment partly consumes the extraction spaces. Closing the remaining spaces

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could retrocline the anterior teeth and retracts the facial profile. Williams and Hosila (1976) found that orthodontic treatment with extraction of premolars was accompanied by changes of the soft tissue profile. In some cases these changes improved the facial aesthetics; in others an undesired profile outcome could be seen. For this reason, a carefully studied extraction policy, accounting for all possible changes, would be very valuable. The same study indicated that orthodontic treatment with extraction of four first molars results in less incisor retraction than cases treated with extraction of four-first premolars or maxillary first premolars and mandibular second premolars. Clinical observation points in the same direction: therapy with more posteriorly situated extraction seems to result in less incisor retroclination. De Castro (1974) recommended extraction of second premolars in cases where retraction of anterior teeth has to be avoided. By this choice, the closing of extraction spaces after alignment would be mainly realized by mesial movement of posterior teeth instead of distal movement of anterior teeth. An important motivation factor for orthodontic treatment is improved dentofacial appearance (Gosney, 1986 ; Birkeland et al 1999). The relationship between physical appearance and perception of an aesthetic deviation, and the impact of such a deviation on self-esteem and body image are important issues in determining the benefits from orthodontic treatment. Attention should be given to the specific occlusal and aesthetic deviations that cause concern to the patients, and assumptions based purely on the general occlusal condition should be avoided (Gosney, 1986). A variety of social, cultural, and psychological factors, and personal norms influence perception of physical attractiveness (Jenny, 1975; Baldwin, 1980). Studies in social psychology indicate that physical attractiveness plays a major role in social interaction and influence the impression of an individual’s social skill (Baldwin, 1980; Shaw, 1981). As orthodontic treatment improves facial appearance, it is assumed to increase self-worth. However, this hypothesis has been difficult to verify. One study on self-concept changes during orthodontic treatment showed no long-lasting effect on self-esteem (Korabit, 1994). Another

indicated that a high self- esteem could be related to orthodontic concern (Birkeland et al 1996). Whilst many indices exist to record malocclusion, it is important to distinguish those that classify malocclusions into types (Angle, 1899) and those that record prevalence in epidemiological studies (Bjork et al 1964), from those indices that attempt to record treatment need for priority. Furthermore, indices used to record treatment success and treatment difficulty will have differing requirements. Many indices have been developed with the intention of categorizing malocclusions into various groups, according to the urgency and need for treatment (Summers, 1971; Salzmann, 1968; Linder-Aroson, 1974; Lundstrom, 1977; Grainger, 1967; Draker, 1960). Individuals with greatest treatment need can then be assigned priority when orthodontic resources are limited and when the availability of treatment is unevenly spread. Similarly, individuals with little need for treatment can be safeguarded from the potential risks of treatment (Shaw, 1988). The early efforts to design indexes were the product of workers in the public health field, trying to establish data about pathologic or handicapping dental conditions. Thus, Klein et al developed the DMF (decayed, missing, filled) scale that was and is the ultimate in simplicity is measuring dental conditions for large numbers of people. Early efforts to quantify the extent of malocclusion were based on the assumptions about ideal occlusion previously outlined. As a result, researchers like Graineger produced data on that basis. From this data, he developed the Orthodontic Treatment Priority Index. Salzmann published the Handicapping malocclusion Assessment (the Salzmann index) that also measures variations from this arbitrary standard. Others working on this vein of thought include Massler and Frankel, VanKirk and Pennell, Bjork et al, Summers, Freer and Adkin, Ingervall and Ronnerman, and Helm. Experience made it apparent to some observers that variation from a very narrow ideal often failed to equitably identify the truly handicapping malocclusions. Because of the CHAMPUS program, the Armed forces of the United States in 1976 contracted with the National Research Council to organize a work force to define “Seriously handicapping orthodontic conditions”. An excellent committee

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History of Malocclusion Indices

of highly qualified workers in the field labored for some time but was unable to produce such a definition. HL Draker Suggested a different approach in which selected deviations from ideal were scored and weighted. He called it the Handicapping Labiolingual Deviation index or HLD Index. Careful reading of the original article makes it clear that he made some of them wanting. Then he suggested some changes but never reported any more test results in his article. A number of indices have been introduced, however, based on his suggestions and have been called an HLD Index. Cons et al approached the index problem from purely the appearance standpoint and developed the Dental Aesthetic Index. They generally used the opinions of the lay public as to what constituted unacceptable dental arrangements from the aesthetic standpoint. The Dental Index has been accepted by the World Health Organization as a screening tool. Meanwhile in Europe, probably because of government pressure, much effort was spent on defining which patients qualified as needing orthodontic treatment to be paid for by the government. It would be helpful to remember the extent to which dentistry is socialized in many of those countries. Brook and Shaw in 1989 developed the Index of Treatment Need used in the United Kingdom. Richmond et al also developed the PAR (Peer Assessment Rating) Index (1990, 1992) as a tool to measure the results of orthodontic treatment and not the need. Espeland et al produced a new approach in Norway for their mixture of public and private funding of treatment. Draker HL, Albany NY in 1960 proposed the Handicapping Labiolingual Deviation (HLD) index which was an attempt to obtain a method which would complement and perhaps substitute for clinical judgment which, although useful to a degree, is vulnerable because it is entirely subjective. The three planes commonly used for orthodontic orientation, i.e. the sagittal plane; frankfurt plane and orbital plane are the basis for HLD measurements. The intention was to measure the presence or absence, and the degree, of the handicap caused by the components of the index, and not to diagnose “malocclusion”. He found that labiolingual deviations from a fictitious norm rather than the state of occlusion are of

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epidemiological importance in establishing prevalence rates for physically handicapping orthodontic defects, and degree of the physical handicap. These deviations are measurable in definite units. Fastlicht J in 1970 did a study to compare the degree of crowding of the anterior teeth in cases which were treated orthodontically years before with those which were not treated, in order to determine whether treatment had an influence through time on the crowding of the incisors. He concluded that the crowding of the incisors was an anatomic-physiologic phenomenon of adaptation observed in orthodontically treated cases, as well as in untreated cases, which resulted from the combination of several factors, such as sex, anatomic predisposition of dolichocephalic or long-faced persons, tooth-size discrepancies, exaggerated overbite, extrusion of the canines, reduction of the intercanine width, age, muscle function, and, in some cases, imperfect mechanotherapy. There was less crowding of the incisors in the treated group. Thus, it was assumed that treatment had a favorable influence over the stability of the dental arches. Summers CJ in 1971 developed the Occlusal Index (OI) Nine characteristics were scored in the occlusal index: dental age, molar relation, overbite, overjet, posterior cross-bite, posterior open-bite, tooth displacement (actual and potential), midline relations and missing permanent teeth. The purpose of describing these scoring procedures in detail are as follows : to standardize scoring procedures, to indicate how each scoring procedure is mutually exclusive and enable investigators to apply subjective classification to the objective measurements. The OI was tested for validity, validity during time, and intraexaminer reliability. The OI appears to correlate highly (rs = 0.920) with the clinical standard indicating high validity; the OI also appears to be valid during time, since the average group scores did not decrease during time. Intraexaminer reliability was very high (rs = 0.963). Little RM in 1975 proposed the Irregularity index, a scoring method which involved measuring the linear displacement of the anatomic contact points (as distinguished from the clinical contact points) of each mandibular incisor from the adjacent tooth anatomic point, the sum of these five displacements representing

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History of Orthodontics

the relative degree of anterior irregularity. Perfect alignment from the mesial aspect of the left canine to the mesial aspect of the right canine would theoretically have a score of 0, with increased crowding represented by greater displacement and, therefore, a higher index score. Rather than measuring from contact point to ideal arch form or to another subjective point, the actual linear distance between adjacent contact points is determined. Such a measure represents the distance that anatomic contact points must be moved to gain anterior alignment. Eismann in 1980 carried out an investigation on pre-treatment, post-retention and follow-up casts of 200 patients treated with removable orthodontic appliances to assess changes resulting from orthodontic treatment. He found that the extent of abnormal criteria between the initial casts and the post-treatment casts was reduced on average to about one-fifth and this improvement generally remained constant over the follow-up period, apart from slight further improvements resulting from reduction of extraction spaces. Berg R, Fredlund A in 1981 tried to evaluate the degree of morphological improvement achieved during treatment. 30 cases were selected; the recordings were made on pre- and post-treatment plaster models. The degree of improvement, or change during treatment, was assessed by means of a treatment priority index worked out by a study-group of Norwegian orthodontists. The findings indicated that evaluation of treatment results by an index score system may be a contribution to the quantification of the changes achieved; may relate the degree of change to the condition before treatment and perhaps to the need for treatment; and may also permit comparison of the effects of different treatment methods. Shaw WC in 1983 compared the orthodontic manpower, finance and training in England and Wales, the Netherlands, Norway, Sweden and Denmark to find out the criteria for general acceptance of an adequate orthodontic service. The following criteria were concluded: (a) treatment should be available to all those in need, (b) the cost should be reasonable, (c) treatment should be of a satisfactory standard. The principles emerging from the comparison that seemed to be relevant to these criteria were—(a) acceptance of the principle that the majority of

treatment be undertaken or at least supervised by specialists, (b) improvement in the ratio of specialists to susceptible age groups by maximizing training capacity, (c) extension of the role of dental surgery assistants, (d) guidelines to eliminate unnecessary treatment of acceptable malocclusions. Brook PH, Shaw WC in 1989 conducted a study to formulate a valid and reproducible index of orthodontic treatment priority using 222 patients referred to a regional orthodontic center for advice or treatment. To simulate the use of the indices in a screening program, 333, 11–12 year old school children were also examined. The functional and dental health component of the index was based on the index of treatment priority used by Swedish Dental Board with five grading, grade 1 representing little or no need for treatment and grade 5 representing great need of treatment. The second part of the overall assessment of treatment priority, the aesthetic component was based on the SCAN index (Standardized Continuum of Aesthetic Need). The dental photographs of the patients were evaluated on a 10-point scale in the aesthetic component. Satisfactory levels of intra- and interexaminer agreement was obtained and it was proposed that the main benefit by use of this index to the patient of orthodontic treatment would be in improved aesthetics and socialpsychological well-being and additionally the effect this may have on attitudes to dental health. Richmond S, Shaw WC, O’Brien KD, Buchanan IB, Jones R, Stephens CD, et al in 1992 developed the PAR (Peer Assessment Rating) index to assign a score to various occlusal traits which make up a malocclusion. The individual scores were summed to obtain an overall total, representing the degree a case deviates from normal alignment and occlusion. The score of zero indicated good alignment and higher scores (rarely beyond 50) indicated increased levels of irregularity. The overall score was recorded on the pre- and post-treatment dental casts. The difference between these scores represented the degree of improvement as a result of orthodontic intervention and active treatment. After all 272 cases were evaluated by 74 examiners and they concluded that the PAR index provided a single summary score for all the occlusal anomalies and may be used for all types of malocclusions, treatment modalities and

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History of Malocclusion Indices

extraction/non-extraction cases. The score provided an estimate of how far a case deviates from normal and the difference in scores for preand post-treated cases reflected the perceived degree of improvement and therefore the success of treatment. Richmond S, Shaw WC, Roberts CT, Andrews M in 1992 developed a method for relating numerical change in the weighted PAR scores to consensus professional judgments in order to express the degree of improvement resulting from treatment. A panel of 74 examiners was asked to examine 128 pairs of dental casts. Using this index, it was revealed that at least 30 percent reduction was needed for a case to be judged ‘improved’ and a change in score usually of 22 to bring about a change judged to be ‘greatly improved’. It was concluded that for a practitioner to demonstrate high standards, the proportion of an individual’s case load lying in the ‘worse or no different’ category should be negligible and the mean percentage reduction should be as high as possible (greater than 70 percent). The greater the mean percentage reduction in weighted PAR scores the higher the standard of orthodontics achieved. If the mean percentage reduction is high and the proportion of cases that have been ‘greatly improved’ is also high, this indicates that the practitioner is treating a great proportion of cases with a clear need for treatment, to a high standard. Richmond S, Andrews M in 1993 assessed the outcome of treatment provided by a sample of Norwegian orthodontists using objective measures of assessment. A sample of 220 cases was collected from Norwegian specialist orthodontists who had agreed to participate in this study. The index of orthodontic treatment need and the PAR index were applied to the preand post-treatment cases. They concluded that the indices could be used to identify differences not only between individual practitioners, but also health care systems in different countries. It was confirmed that the Norwegian orthodontists were producing a high standard of orthodontic treatment. Buchanan IB, Shaw WC, Richmond S, O’Brien KD, Andrews M in 1993 compared the relative merits of the PAR index and Summer’s Occlusal Index in terms of validity and reliability. A panel of 74 examiners rated 256 sets of study

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models. They found that the occlusal index was fairly complicated in use and incorporated several weighting mechanisms appropriate to each developmental stage. The PAR index was a simple, easy to grasp method of assessing treatment standards as opposed to the more complicated approach of Summer. On the basis of this study it was found that the PAR index is as reliable and as valid a method of assessing orthodontic treatment outcome as is the occlusal index. O’Brien KD, Shaw WC, Roberts CT in 1993 studied the effectiveness of orthodontic treatment provided by a sample of 17 hospital based orthodontic departments. They used index of orthodontic treatment need and the PAR index as a measure of orthodontic treatment need and standard of treatment respectively, in 120 consecutively started patients from each department. The influence of operator, treatment methods and individual departments upon treatment outcome in terms of dento-occlusal change was also assessed. They found that the hospital orthodontic service provided treatment of a high standard. It was also seen that the greatest influence upon the standard of treatment was the choice of treatment methods and operator experience. Two arch fixed appliances were found to be more effective than single arched fixed appliances and removable appliances. Single arch fixed appliances were more effective than removable appliances. There was also an additional effect arising from the aspirations of the consultant and supporting staff. Kerr WJS, Buchanan IB in 1993 used Peer Assessment Rating Index to assess the improvement produced is a series of 150 cases treated with removable appliances and to ascertain in which circumstances they performed most successfully. The pre- and post-treatment study models were used to assess the effectiveness of the appliance. As measured by the PAR index 89.3 percent of a group of patients selected as suitable for treatment with removable appliances were either ‘improved’ or ‘greatly improved’. Of 10.7 percent cases which were classified as being ‘worse, no different’, six were mixed dentition cases where the treatment objectives were limited to the alignment of one incisor tooth and only seven were judged as

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being unsuitable for removable appliances on the ground of their malocclusion. Richmond S, Roberts CT, Andrews M in 1994 assessed the need for orthodontic treatment before and after treatment, on a systematic sample of 1225 cases, using the Index of Orthodontic Treatment Need (IOTN). The results showed that the number of patients needing orthodontic treatment on aesthetic grounds after appliance treatment fell by 27 percent for non-prior approval cases and 45 percent for prior approval cases. The number of patients needing orthodontic treatment on dental health grounds fell by 36 percent for non-prior approval cases and 45 percent for prior approval cases. They also found that upper and lower fixed appliances had the greatest influence or outcome of treatment in terms of aesthetics and dental health. Shaw WC, Richmond S, O’Brien KD in 1995 published an article describing the development and validation of two indices, IOTN (an index of treatment need) and PAR (an index of treatment outcome). To assess the extent to which the indices reflect current orthodontic opinion, a validation exercise was carried out. A panel of 74 dentists was enlisted. Each member of the panel recorded a personal opinion on the need for orthodontic treatment and the change due to treatment of 234 starts and finish study casts, with standardized rating scales. The models were independently scored with the IOTN and the Index of Treatment Outcome (PAR index) by the investigating team. Experience with their use in Europe suggested they have a useful role in resource allocation and planning, monitoring and promoting standards, better uniformity in patient identification and referral, and informed consent. DeGuzman L, Vig PS, O’Brien K in 1995 conducted a study to evaluate the relationship between the subjective estimates of severity of malocclusion and treatment difficulty by using a panel of American Orthodontists and to evaluate the relationship between severity and difficulty, and the PAR index. A group of 11 orthodontists examined the 200 study casts. The results of this study made it possible to derive a set of weightings for the PAR index and to calculate scores that would represent groupings of malocclusion’s severity and treatment

difficulty, according to the perceptions of a panel of orthodontists. As a result, the PAR index may be considered to represent a good approximation of malocclusion severity and treatment difficulty, and may be used as an outcome measure for the assessment of dento-occlusal change. Jenny J, Cons NC in 1996 modified the Dental Aesthetic Index (DAI), an orthodontic index that provides a single score linking the public’s perceptions for dental aesthetics with objective measurements associated with malocclusion. It now had decision-points along the DAI scale defining specified case severity levels. DAI scores of 25 and below represent normal or minor malocclusion with no treatment needed or slight treatment need. DAI scores of 26 to 30 represent definite malocclusion with treatment elective. DAI scores of 31 to 35 represent severe malocclusion with treatment highly desirable. DAI scores of 36 and higher represent very severe or handicapping malocclusion with treatment considered mandatory. Turbill EA, Richmond S, Wright JL in 1996 conducted a study in which subjective grading of cases at the Dental Practice Board of England and Wales was compared to the Peer Assessment Rating Index (PAR) and Index of Orthodontic Treatment Need (IOTN) in assessing 1505 cases sampled at the Board between late 1990 and mid1991. They concluded that some cases rated as ‘greatly improved’ or ‘improved’ by PAR still had substantial residual malocclusion (weighted PAR at finish) and/or residual need for treatment and that the dental advisers disliked PAR’s low weighting of buccal occlusion and residual buccal spaces. Turbill EA, Richmond S, Wright JL in 1996 used the Index of Treatment Need and Peer Assessment Rating index to assess targeting, use of appliances, and standards of outcome for General Dental Service orthodontic cases collected between 1990 and 1991 and compared them with a sample of cases from an earlier study, collected between 1987 and 1988. The samples of cases used in this study were sub-samples from two parent samples, each of around 1500 cases. They concluded that since the 1988 study, there had been a trend to acceptance of more cases with lower need for treatment, but no increase in treatments previously defined as ‘unnecessary’. The standard of completed cases had improved

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History of Malocclusion Indices

slightly in terms of both residual need for treatment and residual malocclusion (IOTN and weighted PAR scores at finish). These limited improvements were apparently associated with increased use of fixed appliances. Buchanan IB, Russell JI, Clark JD in 1996 did a study to investigate the usefulness of the PAR index as a means of differentiating between results achieved by two different fixed appliance techniques: the preadjusted Edgewise and the Begg appliance. A group of 41 cases treated using the Begg appliance and 41 cases treated using the preadjusted Edgewise appliance were gathered. Comparison of results using the monogram and percentage reduction on the two appliance system groups indicated that the cases treated by the preadjusted Edgewise appliance had a better outcome. This comparison showed that there was a significant difference between the two appliance types in terms of treatment success when the monogram, percentage reduction and comparison of the actual PAR scores were considered. Preadjusted Edgewise cases being more successful than the Begg. This difference was much more marked in the cases with low start PAR score than it was in the high start group, where the appliance type seemed to be of less relevance. Birkeland K, Furevik J, Boe OE and Wisth PJ in 1997 used the Peer Assessment Rating index to assess the treatment results in a postgraduate clinic and to assess the occlusion at a 5 year follow-up control, in relation to the original malocclusions, and the changes occurring in the follow-up period. 224 cases were selected and the treatment result was a 76.9 percent PAR score reduction. The treatment success was greatest for Angle Class II division 2 with 80.8 percent PAR score reduction, closely followed by Angle Class II division 1 (78.4 percent). Extractions did not significantly influence treatment success and neither did the sex difference. Saelens NA, deSmit AA in 1998 did a study to investigate (in extraction and non-extraction therapy), the initial amount of crowding, the changes in the position of the incisors and molars, the changes in the soft tissue profile, and the clinical outcome. Three groups of 30 patients were investigated. In all cases, the orthodontic treatment moved the molars mesially. The lower incisors remained in about the same position in the

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extraction groups but then proclined in the nonextraction group. The upper incisors were retroclined approximately 2 mm in the extraction groups. A change in lip protrusion was found in the non-extraction group, where tooth alignment was accompanied by proclination. It was concluded that within the appropriate indications, extraction of first or second premolars, or non-extraction therapy with light-wire appliances and no extraoral anchorage, leads to good occlusal results without unfavorable changes in the facial profile. Parker WS in 1998 discussed the Handicapping Labiolingual Deviation Index (CalMod), a lawsuit-driven modification of some 1960 suggestions by Dr Harry L Draker, which proposed to identify the worst looking malocclusions as handicapping and offered a cutoff point to identify them. The HLD (CalMod) index went into official use late in 1991, and as of January 1 1998, 135,655 patients had been examined orally by qualified orthodontists and screened using this index. Of this number, 49,537 were found to have a score of 26 or greater, and study models of these patients were produced and screened by board-qualified orthodontists for the fiscal intermediary. The HLD (CalMod) index proved to be a successful tool to identify a large number of very disfiguring malocclusions and two known destructive forms of malocclusion (deep destructive impinging bites and destructive individual anterior cross bites). These were all then certified as medically necessary handicapping malocclusions. Firestone AR, Hasler RU, Ingervall B in 1999 did a study to investigate the objective need for treatment and the treatment results for two groups of patients who were treated in a dental school orthodontic clinic approximately 10 years apart and to investigate factors predictive of change in PAR score and the length of treatment. They concluded that changes in treatment techniques and the introduction of new materials have had a significant positive effect on treatment outcome in a postgraduate dental school orthodontic clinic and improvement in occlusion and alignment was primarily the result of a reduction in overjet, an increase in the alignment of the maxillary anterior teeth, and a reduction in overbite. Hamdan AM, Rock WP in 1999 did a study to re-test the validity of the PAR index against

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assessments by West Midland Consultant Orthodontists, to compare the validity of three new weighting systems and to apply the best new weighting system to unweighted PAR scores and examine the effect for each malocclusion class. Eighty sets of pre- and post-treatment dental casts, representing equal numbers of Class I, Class II division 1, Class II division 2, and Class III cases were randomly selected. The results supported the hypothesis that it is inappropriate to group all orthodontic cases together to derive a generic weighting formula and that weightings should be derived separately for each malocclusion class. The most valid PAR index weightings were derived by multiple regressions, modified by the addition to base weights for buccal occlusion and lower anterior displacements. Assessments of treatment outcome using point and percentage reductions were more valid than using the original PAR monogram. Arnett GW, Jelic JS, Kim J, Cummings DR, Beress A, Worley M et al in 1999 presented a technique for soft tissue cephalometric analysis. Forty-six adult white models comprised the cephalometric database for this analysis. They concluded that, (a) natural head position must be adjusted for some patients using clinical judgment,(b) the Soft Tissue Cephalometric Analysis (STCA) is a facial diagnostic tool, (c) STCA diagnosis is used for cephalometric treatment planning(CTP), (d) clinical facial analysis is used to augment cephalometric information, (e) absolute projection values for important soft tissue structures are measured to the true vertical reference line, (f) the true vertical reference line is placed through subnasal and (g) the true vertical reference line is moved forward from subnasale when maxillary retrusion is indicated by clinical and cephalometric findings. Birkeland K, Boe OE, Wisth PJ in 2000 did a study to measure aesthetic and occlusal changes from 11 to 15 years of age using the Index of Orthodontic Treatment Need (IOTN) and Peer Assessment Rating (PAR) Index, to compare treated and untreated groups using the same indices. Out of a sample of 359 children simple treatment with removable appliances was used in 23.8 percent. They found that children were less critical in their aesthetic evaluation compared with that noted by the examiners. The

post-treatment mean PAR scores of 5.8 in this study with 6.0 in the former showed a high standard of treatment results. Cooper S, Mandall NA, Dibiase D, Shaw WC in 2000 did a study to establish whether IOTN was reliable over time, between the age of 11 and 19 years old, for subjects who had not received orthodontic treatment and to investigate the changes over time in the occlusal traits that comprise the dental health component of IOTN. Study casts of a longitudinal sample of 11 year old (n = 314), 15 year old (n = 314) and 19 year old (n = 142) subjects were examined. They found that the dental health component of IOTN is reliable between 11 and 19 years despite temporal changes in the separate occlusal traits that comprise the index and IOTN DHC grading at the age of 11 years is likely to be similar when the patient reaches 19 years. They also found that most of the occlusal traits contributing to IOTN DHC improved over time except posterior cross bite and displacement of contact points that worsened between 11 and 19 years. Fastlicht J in 2000 developed a visual cephalometric analysis based on two geometric constructs the “Tetragon”, a polygon that represents the maxillo-dento-mandibular complex, made up of reliable and familiar cephalometric landmarks—the palatal plane, the mandibular plane, and the axes of the maxillary and mandibular central incisors, the “Trigon”, a complementary triangle situated above the Tetragon and formed by one plane that is intrinsic to the Tetragon—the palatal plane (PNS-ANS)—and two that are extrinsic – the pterygo-palatal plane (Pt-PNS). He concluded that the Tetragon and the Trigon provide a clear picture of the position of the maxillo-dentomandibular structures within the craniofacial complexes and that this visual cephalometric analysis could be a useful diagnostic tool for treatment planning, surgical preparation, and evaluation of growth, treatment progress, and post-treatment results. Pinto N, Woods M, Crawford E in 2000 conducted a study, designed to determine the influence of the pretreatment vertical facial pattern on post-treatment occlusal change (as assessed with the PAR index) occuring after fixed-appliance orthodontic treatment of patients managed by one orthodontist with consistent

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aims and methods. Pretreatment, post-treatment and follow-up casts of 60 patients were assessed by the PAR index. The pretreatment vertical facial pattern for each subject was established using the Jarabak Facial Height Quotient. The results of this study suggested that the pretreatment vertical facial pattern, at least on its own, is not likely to be predictive of the amount of post-treatment occlusal change. Beatrice M, Woods M in 2000 conducted a study designed to assess whether or not rotational changes occurring during or after treatment, in one accepted indicator of vertical facial dimension, the Facial Axis, are in any way related to post-treatment occlusal changes. The pretreatment, post-treatment and follow-up cephalograms of 55 cases were assigned numbers and arranged in random order by an independent observer before being traced and digitized by one examiner. The pretreatment vertical facial pattern for each subject was established using the Jaraback Facial Height Quotient. Occlusal assessment using the pretreatment (T1) post-treatment (T2) and follow-up (T3) models was undertaken using the PAR index. They concluded that the facial axis tends to change in the long-term following routine, comprehensive orthodontic treatment. A change in the Facial Axis does not seem to be directly related to the underlying vertical facial type. Long-term post-treatment Facial Axis changes and long-term changes occurring in the occlusion are not directly related. Wijayaratne D, Harkness M, Herbison P in 2000 conducted study to determine in children with Class II, division 1 malocclusions treated with functional appliances, first, if lower incisor proclination affects the assessment of treatment outcome using the PAR index and, second to evaluate the effectiveness of functional appliances after adjusting the PAR score for any lower incisor proclination. The subjects in this study were 43 consecutively treated children who were assigned to either an untreated group, a group treated with Frankel function regulators, or a group treated with Harvold activators. The PAR index showed that improvements were made during treatment with functional appliances in 50 percent of the cases in this study; however, cephalometric analysis, which is not part of the PAR assessment, showed that in a

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proportion of cases the overjet reduction was achieved by lower incisor proclination, which is considered by some authorities to be unstable. Daniels C, Richmond S in 2000 formulated a study to propose orthodontic indices to assess treatment need, complexity, treatment improvement, and outcome based on international professional opinion, intended for use in the context of specialist practice, and to compare treatment thresholds in different countries and serve as a basis for quality assurance standards in orthodontics. An international panel of 97 orthodontists from nine countries was asked to judge 240 dental casts for assessment of treatment need and 98 paired pretreatment and post-treatment cases for assessment of treatment outcome. The outcome was a new index, Index of Complexity, Outcome and Need (ICON) which was based on the average opinion of a large panel of international orthodontic opinions. For the first time the design of the index had been specifically developed to enable assessments of treatment need and outcome using one set of occlusal traits. The accuracy of the index to reflect professional opinion for a diverse sample of cases was estimated at 84 percent for decisions of treatment need and 68 percent for treatment outcomes. The method was heavily weighted by aesthetics. Kim JC, Mascarenhas AK, Joo BH, Vig KWL, Beck FM, Vig PS in 2000 conducted a study to assess the value of cephalometric variables in predicting orthodontic outcomes for patients with Class II malocculusions and variables that are most useful as predictors of pre-PAR, post-PAR, percent PAR reduction, and treatment duration. This study evaluated selected cephalometric variables with the intention of identifying predictors of the occlusal outcome of orthodontic treatment in 223 patients with Class II malocclusions. The results showed that Cephalometric variables explained 39.2 percent of the variation in the pre-PAR scores; they suggested that cephalometrics may be more valuable as a diagnostic tool than a prognostic tool. The selected cephalometric variables explained only 18 percent of the variance of the post-treatment occlusal result (post-PAR). Sixteen percent of the variance in improvement of the malocclusion (percent PAR reduction) could be explained by cephalometric variables. Mascarenhas AK, Vig K in 2002 did a study to compare the quality of orthodontic treatment

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provided by orthodontists in private practice (experts) with that of graduate orthodontic residents (novice). The sample consisted of 143 cases treated by private practice orthodontists and 165 cases treated at the graduate orthodontic clinic. The results of study showed that although there was no difference in the final occlusal outcome there was a difference in the treatment duration between the graduate educational setting and private practice, favoring the GOC. These results indicated that the clinical proficiency of graduate orthodontic program was comparable to that of highly experienced private practice orthodontists. Yang-Powers LC, Sadowsky C, Rosenstein S, BeGole EA in 2002 conducted a study to determine whether dental relationships at the end of orthodontic treatment in a university postgraduate clinic are within the ABO’s limit for passing the phase III examination, to assess the contribution of each of the 8 components of the OGS to the total OGS score, to determine whether treatment outcome is different for the various malocclusion categories, and to investigate treatment outcome in a sample of cases that passed ABO certification compared with cases treated in a university clinic. The sample used in this retrospective study consisted of records of 96 patients treated in the graduate orthodontic clinic at the University of Illinois at Chicago. They concluded that there was a statistically significant difference (P < 0.05) in overall treatment outcome (OGS score) between the university group (average total score 45.54) and the ABO group (total score 33.88). Significant differences in treatment outcome (using OGS scores) were found between the university and the ABO groups for the components of root paralleling (panorex), occlusal contact, and overjet. Occlusal contact and overjet were significantly higher (worse) in the university sample. Panorex was significantly higher (worse) for the ABO group. The ABO group exhibited better finishing details in the anterior segment and in the second molar region than did the university group. Cassinelli AG, Firestone AR, Beck MF, Vig KWL in 2003 did a study to test whether objective criteria can be used to identify difficult and complex cases before treatment, and to determine whether objective measures of malocclusion

severity (e.g. the PAR index) or an index of orthodontic treatment need (e.g., the IOTN) could be used to differentiate between easy and difficult cases. A further aim was to investigate whether factors related to the treatment or the patients were associated with orthodontists’ evaluations of cases as easy or difficult after treating the patients. Ten orthodontists practicing in Ohio were selected by telephone solicitation, and each orthodontist was asked to identify the complete records of 10 treated cases he or she judged as having been easy to treat and 10 cases as having been difficult to treat. The cases selected were to be chosen from the last 100 patients the orthodontist had treated. This study showed that complexity, or difficulty in achieving an ideal occlusion, increases as the severity of the initial malocclusion increases. Complex cases are associated with patients who are seen more often and receive repeated warnings about compliance problems. Easy cases have less severe malocclusions initially, are associated with compliant patients, and are more likely to have 2-phase treatment. Weerakone S, Dhopatkar A in 2003 conducted a study to demonstrate the potential of a new software package, clinical outcomes monitoring program (COMP), for use in clinical research by carrying out a limited audit for illustration. The program can collect data from PAR, IOTN, and ICON indexes with built-in “Wizards” capable of calculating all 3 scores automatically. The COMP database contained information on 205 consecutively finished cases over a period of approximately 1 year after the introduction of the COMP. This study demonstrated that this approach is useful in comparing outcomes from various providers and monitoring the general quality of treatment in a practice with many orthodontists. Lieber WS, Carlson SK, Baumrind S, Poulton DR in 2003 tested the reliability and subtraction frequency of the study model— scoring system of the American Board of Orthodontists (ABO). Thirty-six post-treatment study models were selected from six different orthodontic offices. They found that the greatest limitation of the ABO index, its dependence on landmark identification. Most of the scoring involved measuring “landmark-to-landmark” linear distances using the ABO scoring tool.

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Reliability was lower than expected, suggesting that the ABO index may still be overly subjective. Subtraction frequency revealed a significant emphasis on second molars. Cangialosi TJ, Riolo ML, EdOwens S, Dykhouse VJ, Moffitt AH, Grubb JE et al in 2004 have discussed criteria for determining the acceptability of a case presented for the American Board of Orthodontics (ABO) Phase III clinical examination which is case difficulty. Case difficulty can often be subjective; however, it is related to case complexity, which can be quantifiable. Over the past 5 years, the ABO has developed and field-tested a discrepancy index, made up of various clinical entities that are measurable and have generally accepted norms. These entities summarize the clinical features of a patient’s condition with a quantifiable, objective list of target disorders that represent the common elements of an orthodontic diagnosis: overjet, overbite, anterior open bite, lateral open bite, crowding, occlusion, lingual posterior crossbite, buccal posterior crossbite, ANB angle, IMPA, and SN-Go-Gn angle. The greater the number of these conditions in a patient, the greater the complexity and the greater the challenge to the orthodontist. Read MJF, Deacon S, O’Brien K in 2004 conducted a prospective cohort study. Thirty-two children were included in the study over a 2-year period. Study casts were analyzed with the Peer Assessment Rating (PAR index), weighted with the UK weights. Cephalometric radiographs were analyzed with the Pancherz analysis. This prospective cohort study showed that the modification of the Twin-block appliance was an effective method of treating Class II malocclusion in terms of the morphological effects on the dental and skeletal tissues; and the main theoretical advantages of this appliances over the removable twin-block were that patient cooperation is enhanced and the appliance is active for 24 hours a day, there is no transition phase between the functional and fixed appliances phases, and it is less bulky. Fogle LL, Southard KA, Southard TE, Casko JS in 2004 conducted a retrospective study to provide soft and hard tissue cephalometric analysis of treatment effects after correcting Class II malocclusions in growing patients with moderate to severe mandibular retrognathia and

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to examine the outcomes for growing patients with a range of skeletal anteroposterior and vertical dysplasias, who were treated with orthodontics and growth modification techniques. Pretreatment and post-treatment cephalograms of 100 growing Class II division 1 patients with mandibular skeletal retrusion were divided into 5 groups depending on initial vertical and anteroposterior measurements. Post-treatment soft and hard tissue measurements were assessed and compared between the groups. They concluded that conventional orthodontic therapy successfully correct and Class II division 1 malocculusions in growing patients through a combination of skeletal and dentoalveolar changes, with the greatest changes occurring in patients who initially had the most severe skeletal dysplasias. Janson G, de Souza JEP, Henriques JFC, Cavalcani CT in 2004 did a study to compare the occlusal changes of the FRI and the eruption guidance appliance, using the Peer Assessment Rating (PAR) index. From the treated-patients records of the Orthodontic Department, Bauru Dental School, and two samples of Class II patients were retrospectively drawn. Group 1 consisted of 25 patients treated with the FRI. Group 2 included 30 patients treated with the G series of the eruption guidance appliance known as Occlus-o-Guide. The results of this research showed that there was a similar effectiveness in producing occlusal changes in the two investigated appliances, regardless of treatment time. The main shortcoming of the Frankel appliance was its large size and the initial discomfort and the eruption guidance appliance presented advantages because it was smaller but presented a slightly greater mean treatment time. Abei Y, Nelson S, Amberman BD, Hans MG in 2004 conducted a study to compare orthodontic treatment outcome in a sample of patients divided on the basis of orthodontic provider education by using 2 outcome measures. The first measure was the patient’s perception of the improvement in his or her smile. A visual analog scale (VAS) was used to estimate this variable. Second, we used the ABOI to compare the alignment of the teeth. The goal was to obtain evidence to support the commonly held belief that orthodontic specialists provide better orthodontic care than do general dentists.

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Survey data were obtained from 280 students. In this sample, significantly lower ABOI scores were found per patients treated by orthodontic specialists compared with patients treated by general dentists. Malocclusion is a common oral disorder which manifests itself during childhood and the correction of malocclusion (orthodontic treatment) is frequently carried out during childhood. With the growing demand for orthodontic treatment a variety of clinician-based indices have been developed to classify various types of malocclusion and determine their orthodontic treatment need. These indices can be used in estimating orthodontic treatment need, prioritizing of treatment need in patients referred for orthodontics particularly where there are limited resources for orthodontics among public health care services, and safeguarding for the patients. The most commonly employed malocclusion indices are the Dental Aesthetic Index (DAI), Index of Orthodontic Treatment Need (IOTN), Peer Assessment Rating and Index of Complexity, Outcome and Need (ICON). Generally, among the commonly used indices, IOTN (AC, DHC), DAI and ICON are used to assess the orthodontic treatment needs while ICON and PAR are used to assess the treatment outcome. In some ways, the indices of IOTN, DAI and ICON are similar. All include two components-morphological and esthetic. The difference is that for the IOTN, the esthetic component is separated from the dental health component. All the three indices measure similar traits such as overjet, reverse overjet, open bite, overbite, anteroposterior molar relationship, and displacement. However, the weights of these traits are rated differently by each index. The four indices are described below. INDEX OF ORTHODONTIC TREATMENT NEEDS (IOTN) Brook and Shaw in 1989, developed a valid and reproducible index (Index of orthodontic treatment need—IOTN) to determine orthodontic treatment need. This index attempts to rank malocclusion in terms of the significance of various occlusal traits for an individual’s dental

health and perceived aesthetic impairment. It intends to identify those individuals who would most likely benefit from orthodontic treatment. The index has two components, the aesthetic and dental health components, which rank malocclusion in increasing priority according to aesthetic considerations and dental health implication. Aesthetic Component Aesthetic component (AC) consists of a scale of ten color photographs showing different levels of dental attractiveness. The dental attractiveness of prospective patients can be rated with reference to this scale. Grade 1 represents the most and grade 10 the least attractive arrangement of teeth. The score reflects the aesthetic impairment. Aesthetic Component value indicates patient’s esthetic concern and reflects sociopsychological needs. Grade 1, 2, 3 and 4 — no or slight need for treatment, Grade 5, 6 and 7 — moderate or borderline need for treatment, Grade 8, 9 and 10 — need for orthodontic treatment. Dental Health Component Dental health component (DHC) involves features that might impair the health and function of the dentition. DHC records the various occlusal traits of a malocclusion that would increase the morbidity of the dentition and surrounding structures. The traits of malocclusion are: overjet, reverse overjet, overbite, open bite, crossbite, displacement of teeth, impeded eruption of teeth, buccal occlusion, hypodontia and defects of cleft lip and palate. Functional disturbances are also recorded which included lip competency, mandibular displacement, traumatic occlusion and masticatory or speech difficulties. Only the worst occlusal feature is recorded. The components of DHC are shown in Table22.1. There are five grades. Grade 1 and 2 – no need or slight need for treatment, Grade 3 – moderate or borderline need for treatment, Grade 4 and 5 – need for orthodontic treatment.

History of Malocclusion Indices

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Table 22.1: The dental health component is usually recorded at the chair side by direct examination of the subject but can also be recorded from dental casts need (IOTN) (Shaw et al, 1989) Grade 5 (Need treatment) 5.a Impeded eruption of teeth (except for third molars) due to crowding, displacement, presence of supernumerary teeth, retained deciduous teeth and any pathological cause 5.b Extensive hypodontia with restorative implications (more than 1 tooth missing in any quadrant) requiring pre-restorative orthodontics 5.c Increased overjet greater than 9 mm 5.d Reverse overjet greater than 3.5 mm with reported masticatory or speech difficulties 5.e Defects of cleft lip and palate and other craniofacial anomalies 5.f submerged deciduous teeth Grade 4 (Need treatment) 4.a Less extensive hypodontia requiring prerestorative orthodontic or orthodontic space closure to obviate the need for prosthesis 4.b Increased overjet greater than 6 mm but less than or equal to 9 mm 4.c Reverse overjet greater than 3.5 mm with no mastieatory or speech difficulties 4.d Reverse overjet greater than 1mm but less than 3.5 mm with reported masticatory or speech difficulties 4.e Anterior or posterior crossbites with greater than 2 mm discrepancy between retruded contact position and intercuspal position 4.f Posterior lingual crossbite with no functional occlusal contact in one or both buccal segments 4.g Severe contact point displacements greater than 4 mm 4.h Extreme lateral or anterior open bite greater than 4 mm. 4.i Increased and completed overbite with gingival or palatal trauma 4.j Partially erupted teeth, tipped and impacted against adjacent teeth 4.k Presence of supernumerary teeth. Grade 3 (Borderline need) 3.a Increased overjet greater than 3.5 mm but less than or equal to 6 mm with incompetent lips 3.b Reverse overjet greater than 1mm but less than or equal to 3.5 mm. 3.c Anterior or posterior crossbites with greater than 1 mm but less than or equal to 2mm discrepancy between retruded contact position and intercuspal position 3.d Contact points displacements greater than 2 mm but less than or equal to 4 mm

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3.e Lateral or anterior open bite greater than 2 mm but less than or equal to 4 mm. 3.f Deep overbite complete on gingival or palatal tissues but no trauma. Grade 2 (Little need) 2.a Increased overjet greater than 3.5 mm but less than or equal to 6 mm with incompetent lips 2.b Reverse overjet greater than 0 mm but less than or equal to 1 mm 2.c Anterior or posterior crossbites with less than or equal to 1 mm discrepancy between retruded contact position and intercuspal position 2.d Contact point displacements greater than 1 mm but less than or equal to 2 mm 2.e Anterior or posterior open bite greater than 1 mm but less than or equal to 2 mm 2.f Increased overbite greater than or equal to 3.5 mm without gingival contact 2.g Pre-normal or post-normal occlusions with no other anomalies (includes up to half a unit discrepancy) Grade 1 (None) 1. Extremely minor malocclusions including contact points displacements less than 1 mm

Limitations Aesthetic component cannot be used accurately in mixed dentition. There is a shortage of scientific information regarding the long-term effects of malocclusion. Nonetheless the DHC of IOTN provides a structured method for assessment of malocclusion. PEER ASSESSMENT RATING The Peer assessment rating (PAR) index, previously refered to as the index of treatment standards, was described by S Richmond, W C Shaw, K D O’Briene, I B Buchaman, R Joes, C D Stephens and M Andrew in 1992.The PAR index is a quantitative occlusal index measuring how much a patient deviates from normal alignment and occlusion. This index is designed to measure the efficacy or the outcome of orthodontic treatment by comparing the severity of occlusion on pretreatment and post-treatment casts. The PAR index has five components. 1. Upper and lower anterior segments: Scores are recorded for both upper and lower anterior segment alignment. The features recorded are crowding, spacing and impacted teeth.

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2. Buccal occlusion: The buccal occlusion is recorded for both left and right sides. The recording zone is from the canine to the last molar. All discrepancies are recorded when teeth are in occlusion. 3. Overjet: Positive overjet as well as teeth in crossbite is recorded. The most prominent aspect of any one incisor is recorded. If the two lateral incisors are in crossbite while the centred incisors are with increased overjet of 4 mm, the score will be 3 for crossbite and 1 for the positive overjet, 4 in total. 4. Overbite: The vertical overlap or open bite of the anterior teeth is recorded. 5. Centerline assessment: The centerline discrepancy between the upper and lower dental midline is recorded in relation to lower central incisors. The PAR index is applied to an individual’s preand post-treatment study casts. Scores are assigned to each component. The individual scores are calculated in each component and multiplied by a weight of each component. Scores are summed to obtain a total score that represents the degree a case deviates from normal alignment and occlusion. The degree of improvement as a result of orthodontic intervention is obtained by calculating the difference between the pre- and post-treatment PAR scores. The degree of improvement can be assessed using two different methods: 1. Nomogram: The degree of change is separated into 3 sections: a. Worse or no difference, b. Improved and c. Greatly improved 2. Percentage improvement: This method gives a more sensitive assessment than the nomogram which only provides three broad bands of treatment change. A change of score from 40 to 10 would represent an 80% improvement as would a change from 15 to 3. However, the actual reduction in PAR scores is also relevant as in the first case where there has been a much greater change with a 30 point reduction as opposed to the second case in which the degree of change is less with only a 12 point reduction.

INDEX OF COMPLEXITY, OUTCOME AND NEED The Index of Complexity, Outcome and Need (ICON) has been developed recently and claims among other things, to evaluate orthodontic treatment complexity. ICON is based on the subjective judgments of 97 orthodontists from nine countries. It is a single assessment method to quantify orthodontic treatment complexity, outcome and need. The ICON consists of following five weighted components, Table 22.2: 1. The Aesthetic Component (AC): The dental aesthetic component of the IOTN is used. Once this score is obtained it is multiplied by the weighting of 7. 2. Crossbite: Crossbite is deemed to be present if a transverse reaction of cusp to cusp or worse exists in the buccal segment. This includes buccal and lingual crossbites consisting of one or more teeth with or without mandibular displacement. 3. Anterior vertical relationship: This trait includes both open bite (excluding development conditions) and deep bite. If both traits are present only the highest scoring raw score is counted. Scoring protocol is given in Table 22.2. 4. Upper arch crowding/spacing: The sum of the mesiodistal crown diameters is compared to the available arch circumference, mesial to the last standing tooth on either side. Buccal segment anteroposterior relationship: The anteroposterior cuspal relationship is scored according to the protocol given in Table 22.2 for each side in turn. The raw scores for both sides are added together. Calculation of the Final Scores Once all of the raw scores have been obtained and multiplied by their respective weights, they are added together to yield a weighted summary score for a particular cast. The summed score is interpreted as following: pre-treatment scores give the treatment needs and complexity grades; end of treatment scores gives the acceptability; while (pre-treatment scores)—(4 × post-treatment scores) gives the degree of improvement.

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Table: 22.2: Protocol for occlusal trait scoring (Daniel and Richmond, 2000) Score

0

1

3

4

5

Aesthetic

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1–10 as judged using IOTN AC Upper arch Score only the Less than 2.1–5.0 mm crowding highest trait 2.0 mm either spacing or crowding Upper Transverse Up to 2.0 mm spacing Cross bite Relationship No cross bite of cusp to cusp or worse Incisor Score only the Complete bite open bite highest trait either open bite or over bite Incisor Lower incisor Up to 1/3 1/3–2/3 over bite coverage tooth coverage

2

Buccal segment anteroposterior

Left and right Cusp to Any cusp added together embrasure relation up relationship to but not only, class I, including II or III cusp to cusp

Limitations The PAR is based solely on study models and does not account for changes in facial profile, iatrogenic damage, tooth inclination, arch width or posterior spacing, and is not appropriate for assessment of mixed dentition treatment. DENTAL AESTHETIC INDEX The Dental Aesthetic Index (DAI) was developed by NC Cons, J Jenny, F J Kohaut in 1986 to assess orthodontic treatment need. It is an orthodontic index based on socially defined esthetic norms. The Dental Aesthetic Index (DAI) has been adopted by the World Health Organization as a cross-cultural index. It identifies deviant occlusal traits and mathematically derives a single score. Its structure consists of 10 occlusal features of malocclusion; overjet, underjet, missing teeth, diastema, anterior openbite, anterior crowding, anterior spacing, largest anterior irregularity (mandible and maxilla), and anteroposterior molar relationship. The ten occlusal features are

5.1–9.0 mm 9.1–13.0 mm 13.1–17.0 mm >17.0 mm or impacted teeth 2.1–5.0 mm 5.1–9.0 mm >9.0 mm Cross bite present Less than 1 mm

1.1–2.0 mm

2.1–4.0 mm

>4 mm

1/3 upto Fully covered full covered Cusp to cusp relationship

weighted on the basis of their relative importance according to a panel of lay judges. The codes and criteria are as follows: 1. Missing incisor, canine and premolar teeth: The number of missing permanent incisor, canine and premolar teeth in the upper and lower arches should be counted and recorded. 2. Crowding in the incisal segments: Both the upper and lower incisal segments should be examined for crowding. Crowding in the incisal segments is recorded as following: 0— no crowding; 1—one segment crowded; 2— two segments crowded. 3. Spacing in the incisal segments: Both the upper and lower incisal segments should be examined for spacing. Spacing in the incisal segments is recorded as following: 0—no spacing, 1—one segment spaced, 2—two segments spaced. 4. Diastema: A midline diastema is defined as the space, in millimetres between the two permanent maxillary incisors at the normal position of the contact points.

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5. Largest anterior maxillary irregularity: Irregularities may be either rotation out of, or displacements from, normal alignment. The four incisors in the maxillary arch should be examined to locate the greatest irregularity. 6. Largest anterior mandibular irregularity: The measurement is the same as on the upper arch except that it is made on the mandibular arch. 7. Anterior maxillary overjet: The largest maxillary overjet is recorded to the nearest whole millimeter. 8. Anterior mandibular overjet: Mandibular overjet is recorded when any lower incisor is in crossbite. 9. Vertical anterior openbite. 10. Anteroposterior molar relation: The right and left sides are assessed with the teeth in occlusion

and only the largest deviation from the normal molar relation is recorded. The following codes are used: 0—normal, 1—half cusp, 2—full cusp. Calculation of DAI Scores The regression equation used for calculating standard DAI scores is as follows: (missing visible teeth × 6) + (crowding) + (spacing) + (diastema × 3) + (largest anterior maxillary irregularity) + (largest anterior mandibular irregularity) + (anteriormaxillary overjet × 2) + (anterior mandibular overjet x 4) + (vertical anterior openbite × 4) + (antero-posterior molar relation × 3) + 13. The severity of malocclusion is classified on the basis of the DAI scores as shown in the Table 22.3.

Table: 22.3: Severity of malocclusion and decision of treatment need Severity of malocclusion

Treatment indication

DAI Scores

No abnormality or minor malocclusion Definite malocclusion Severe malocclusion Very severe or handicapping malocclusion

No or slight need Elective Highly desirable Mandatory

< 25 26–30 31–35 > 36

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History of Interproximal Enamel Reduction in Orthodontics • History of Interproximal Enamel Reduction – Ballard – Hudson – Bolton – Kelsten

– – – – – –

Paskow Shillingbourg and Grace Tuverson Doris, Bernard and Kuftinec Sheridan Zachrisson

Interproximal enamel reduction (IER) is understood to be the clinical act of removing part of the dental enamel from the interproximal contact area. The aim of this reduction is to create space for orthodontic treatment and to give teeth a suitable shape whenever problems of shape or size requires attention. In the literature, this clinical act is normally referred to as “stripping”, although other names can be found, such as “slendering”, “slicing”, “Hollywood trim”, “selective grinding”, “mesiodistal reduction”, “reapproximation”, “interproximal wear”, and “coronoplastia”. IER is a critical procedure. Therefore, planning and execution need to be carefully assessed. This treatment should be considered as an exact reduction of interproximal enamel and not just as a simple method to solve problems. HISTORY OF INTERPROXIMAL ENAMEL REDUCTION Interproximal dental stripping has been used by orthodontists for many years. It was initially used to gain space when correcting mandibular incisor crowding or to prevent such crowding. In 1944, Ballard recommended a careful stripping of the interproximal surfaces, mainly from the anterior segment, when a lack of balance is present. In 1954, Begg published his study of

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• Indications of Interproximal Enamel Reduction • Contraindications of Interproximal Enamel Reduction

Stone age man’s dentition, where he referred to the shortening of the dental arch over time, which occurred through abrasion. Although the degree of shortening of the dental arch found by Begg was contested, the existence of this natural reduction led to the publication and development of the technique for interproximal enamel reduction. In 1956, Hudson stated that mesiodistal reduction of the mandibular incisors is only occasionally referred to in the literature, and listed just three previous articles with direct reference to the mesiodistal reduction of mandibular incisors. In his study, Hudson stated that stripping should be carried out with medium and fine metallic strips, followed by final polishing and topical application of fluoride. He stated that it was possible to gain 3 mm of space between mandibular canines, and presented an enamel thickness table for incisor and mandibular canine contact points. In 1958, Bolton published his seminal study titled “Disharmony in tooth size and its relation to the analysis and treatment of malocclusion”. This study, together with Ballard’s study, supported the need in dental dimension discrepancy problems, to use interproximal stripping to correct problems of dental balance.

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History of Orthodontics

In 1969, Kelsten recommended the use of mechanical means to carry out stripping and recommended prior alignment of teeth. He posited that, only after alignment stripping could be simply and accurately achieved. That same year, Rogers and Wagner described an in vitro study that used teeth extracted for orthodontic reasons. These extracted teeth were subjected to stripping and polishing. It was found that if the extracted teeth were treated with fluoride after stripping, they offered greater resistance to acid attacks, mainly in the 48 to 96 hours after the procedure. This scientifically justified the importance, already highlighted by Hudson, of topical fluoride application after stripping and polishing. In 1971, Paskow published an article that recommended the use of mechanical methods of IER (interproximal enamel reduction). In 1973, Shillingbourg and Grace wrote an article entitled “Thickness of enamel and dentin”, which was an important study on enamel and dentin thickness. The results of this study later served as the scientific basis for work on stripping and allowed the amount of enamel that could be safely removed from each dental face to be accurately determined. Also in the 70s, Peck and Peck published articles, on crowding of the mandibular incisors and presented the Peck index. They advised stripping whenever the mesiodistal dimension of the mandibular incisors did not fall within acceptable figures calculable from their index. They claimed that anything in excess would constitute predisposition toward crowding. In 1980, Tuverson published “Anterior interocclusal relations: Part 1”, which presented a highly, detailed description of the stripping technique using a back angle and abrasive disks. In 1981, Doris, Bernard, and Kuftinec concluded that one of the strongest determining factors for dental crowding is the dimension of teeth in the arch. In 1981, Betteridge presented the results of stripping on the anterior and inferior segment after 1 year without retention. She observed some relapse, but concluded that esthetics were clearly acceptable after observation by a panel of three dentists, three orthodontists, and three non-dentists. In 1985, Sheridan published his article “Airrotor stripping” and, in 1987, “Air-rotor stripping

update”. These articles totally revolutionized the technique and aims of interproximal enamel reduction. He recommended: 1. Use of a turbine with carbide drill, instead of diamond disks and strips. 2. Stripping on buccal sectors; in other words, distally on canines or mesially on the second molars on both arches. This achieves greater space and allows the preservation of incisors. 3. Use of stripping procedures to achieve space (up to 8 mm per arch) for the correction of moderate dentomaxillary disharmony, without recourse to extraction or excessive expansion. In 1986, Zachrisson proposed a new direction for stripping: improvement of the shape of the teeth, mainly for incisors and reduction of the black triangular space above the papilla. INDICATIONS The IER (Interproximal enamel reduction) technique has evolved over the years; it was first used only for stripping mandibular incisors, with the aim of preventing and correcting crowding. Areas of application have continued to grow: 1. Tooth size discrepancy: In 1944, Ballard recommended careful stripping of the proximal surfaces of the anterior teeth when there was imbalance. 2. Crowding of mandibular incisors: Stripping was first used to obtain space for the correction and prevention of crowding. 3. Tooth shape and dental esthetics: Stripping can and should be used for the reshaping of enamel on some teeth, thus contributing to an improved finishing of orthodontic treatment and dental esthetics. 4. Normalization of gingival contour and elimination of triangular spaces above the papilla, thus greatly improving esthetics and smile. 5. Moderate dentomaxillary disharmony: This is a primary area of application for interproximal enamel reduction in the technique developed by Sheridan in 1985 and 1987, which allowed space to be obtained for the correction of moderate dental crowding; up to 8 mm per arch could be achieved without the need for extraction or excessive expansion.

History of Interproximal Enamel Reduction in Orthodontics

6. Reduced expansion and premolar extraction. 7. Camouflage of class II and III malocclusions: The use of mandibular stripping can be beneficial in camouflaging slight to moderate class III conditions and overjet. In orthodontic treatment to camouflage class II with the extraction of two maxillary premolars, correcting the crowding and inclination of the mandibular incisors with stripping is an ideal solution. 8. Correction of the curve of spee: For the correction of an exaggerated curve of spee, it is necessary to create a few millimeters of space in the arch. This can be achieved through moderate stripping.

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CONTRAINDICATIONS There are several contraindications for the approximation technique: 1. Severe crowding (more than 8 mm per arch): With application of IER, it would be hazardous to carry out orthodontic correction. There would be risk of excessive loss of enamel and all of the ensuing consequences. 2. Poor oral hygiene and/or poor periodontal environment: IER should not be used when

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there is active periodontal disease or lack of dental stability. Although little scientific evidence exists linking IER and increased dental mobility, it is prudent to avoid this technique in these situations. In addition, IER should not be used when there is poor oral hygiene, the orthodontist could be held responsible for all subsequent iatrogenic activity. Vanarsdall has called attention to the potential deleterious consequences. 3. Small teeth and hypersensitivity to cold: Stripping should not be used in these situations, as the risk of the appearance of or an increase in dental sensitivity is great. 4. Susceptibility to decay or multiple restorations: There is a risk of causing imbalance in unstable oral situations, although the stripping of restorations, instead of enamel surfaces, is an option to consider. 5. Shape of teeth: Stripping should not be carried out on “square” teeth—teeth with straight proximal surfaces and wide bases—as these shapes produce broad contact surfaces, and could potentially cause food impaction and reduce interseptal bone.

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History of Invisalign

• Historical Perspective of Invisalign • What Exactly the Invisalign Means? • Developing the Invisalign Brand • Philosophy of Invisalign • Fabrication of Invisalign • Principle of Stereophotolithography

• Summary of the Invisalign Technique • Indications of Invisalign • Advantages of Invisalign • Disadvantages of Invisalign • Limitations of Invisalign • Procedure of Treatment with the Invisalign • Benefits of Invisalign

As far back as 1945, orthodontists realized that a sequence of removable plastic appliances could move teeth toward a predetermined result. Some orthodontists even made simple plastic “aligner trays” in their offices for minor adjustments. But it took an adult who’d just had braces to take the concept a step further. Invisalign was the brainchild of Zia Chishti and Kelsey Wirth, graduate students in Stanford University’s MBA program. Wirth had traditional braces in high school (she reportedly hated them). Chishti had finished adult treatment with traditional braces and now wore a clear plastic retainer. He noticed that if he didn’t wear his retainer for a few days, his teeth shifted slightly — but the plastic retainer soon moved his teeth back the desired position. In 1997, he and Wirth applied 3D computer imaging graphics to the field of orthodontics and created Align Technologies and the Invisalign method. With a boost from ample Silicon Valley venture funding, Align soon took the orthodontic industry by storm. Dentists and other dental companies were skeptical at first, because neither

• • • • • • • • •

24

Care of Teeth with Invisalign Study 1 Study 2 Study 3 Study 4 Study 5 Study 6 Study 7 Other Studies

Chishti nor Wirth had any professional dental training. Invisalign braces were first made available to the public in May, 2000 and proved extremely popular with patients. Soon similar products began appearing on the market, made by GAC, 3-M Unitek, Ormco, OrthoClear, and others. Manufactured by American dental product manufacturer Align Technology, Inc., these aligners are based on the suggestions of dentist Dr H.D. Kessling, who first proposed the removable tray alternative to braces in 1945. Of great importance was Dr Kessling’s idea that the removable tray be part of a series of trays, with each tray forcing teeth to maneuver one step further into line. In 1998, Align Technology received full FDA approval for Invisalign as a Class II medical device. Align Technology continues to get FDA testing and approval for modifications made in the years since. Nearly one million patients have used Invisalign under the guidance of their dentists, orthodontists and cosmetic surgeons. When used properly, these aligners get the same or similar results as traditional braces.

History of Invisalign

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HISTORICAL PERSPECTIVE OF INVISALIGN The movement of teeth through sequential stages, individually planned by a set up in casts, and the use of elastomeric appliances was initially suggested by: Remensyner (1926) when he introduced the FLEX-O-LITE gum massaging appliance, through which reported minor tooth movements and Kesling (1945) by introducing a vulcanite appliance called the Tooth Positioner. Though thermoplastic sheets were manufactured as far back as 1896, thermoforming as a process was not known until a little before 1950. The Dental Contour Appliance was manufactured using an industrial grade vacuum former and reported by Nahoum (1964). Modlin (1974) reported realignment of teeth using vacuum formed appliances. Ponitz (1971), McNamara et al (1985) described the use and efficacy of invisible retainers. The Essix System was described by SHERIDAN et al. for fabricating retainers in 1993. Rinchuse and Rinchuse described active tooth movement with the same in 1997. Lindor and Schoff (1998), Hilliard (2000), Armbruster (2003), Giancotti (2004) and others have contributed to the treatment possibilities with the Essix System. The limitations of all Essix appliances were the small magnitude of changes achieved, associated with the technical difficulties, to manually subdivide, in stages, a movement, desired in several small progressive movements. The Invisalign System was developed in 1998 by Align Technology. This was the first technique to be based on 3D Digital Technology. A series of algorithm stages were produced to move teeth into 0.015–0.025 mm, successive precise movements using computer programmes that manipulate the virtual images of the individual malocclusion. Chisti and Wirth, 2 MBA Students from Stanford University were credited with the formation of Align Technology. Boyd et al (2000) published the first clinical study carried out in the Pacific university, California reporting successful treatment outcomes in cases with mild crowding and spacing between 3–6 mm.

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Boyd and Vlaskalic(2001), Womack (2002), Norris(2002), Miller(2002), Christianson (2002), Joffe (2003), Faltin (2003) have documented successful treatment outcomes and deliberated on the finer nuances of Invisalign therapy. Lagravere (2005) conducted a systematic review on the system. The authors could make no conclusion from the same about the indications for, limitations of and outcomes of use of the Invisalign system because the author found no study that quantified treatment effects or accomplishment of treatment goals using it. Djeu et al (2005) assessed the treatment outcome of Invisalign and traditional orthodontic treatment compared with the American Board of Orthodontics objective grading system and found treatment effects with Invisalign deficient in certain respects. Tuncay (2006) edited a publication on the Invisalign concept and its clinical management. BOYD (2006, 2008) demonstrated use of Invisalign in a surgical case, and reviewed previous Invisalign studies showing significant limitations for complex tooth movement with current case reports showing successful treatment of moderate to severe malocclusions, attributing it to technological advancements in the system during a decade of its existence. The Clear Aligner concept and branding of an alternative low-cost orthodontic appliance system to both orthodontists and general dentists was introduced by TAE WEON KIM (2004).The system uses digital aid combined with manual manipulation to fabricate aligners. Kim (2007) authored the Clear Aligner Manual. The Orthoclear system introduced itself as an alternative to Invisalign.CHISTI, WEN & Riepenhausen (2005) were the founders of the same. Miller, Crawford and Nanda (2006) described case reports with the Orthoclear system. Orthoclear was involved in a legal battle over patents with Invisalign and a settlement was reached in 2006 wherein Orthoclear decided to stop operations in the US. 3D Ortholine was established as a system offering aligner therapy by Abouhassan (2006) and inculcated an advanced system of virtual set ups and appliance design where special emphasis was placed on the sequential division of tooth

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228

History of Orthodontics

movement to enhance patient comfort and increase the scope of tooth movements with aligner therapy. Vaid and Abouhassan (2008) reported clinical reports and technological parameters of the system, designed to provide efficacy. Long-term results were still awaited. Profit (2007) described a role for Aligner Therapy in treating complex malocclusions with limitations in specific scenarios and predicted a future for this method of treatment. Namiranian (2008) studied the effect of aligner thickness on stress production and concluded that thick and medium aligners were more likely to produce effective tooth movement compared to medium aligners.Different Systems of Plastic aligners differ in the clinical and laboratory steps and the modifications possible, that they offer the operator. A lot of the published data is “system based “rather than “therapy based” and has commercial or system specific allegiance to it. The literature on the therapy is definitely encouraging, but is mostly anecdotal including case reports or clinician’s innovations. Randomized clinical trials that follow the CONSORT statement are needed to evaluate the treatment effects of Aligners. Technological analysis of the biomechanical properties of the materials used and the permutation of tooth movements effectively possible, with an organized classification of stages involved will and should be the trend of future research. WHAT EXACTLY THE INVISALIGN MEANS? Invisalign refers to a series of clear, removable heavy-duty plastic aligners that gradually correct minor crookedness and gaps, overcrowded teeth, overbites and/or minor underbites. When considering your options, there are a number of reasons to select this procedure over other choices such as metal braces, crowns, veneers and implants. DEVELOPING THE INVISALIGN BRAND So where does Invisalign fit into this picture? The Invisalign brand was first launched in America in 1999. Invisalign products work in much the same way as conventional brackets in that appliances are fitted to your teeth, and those appliances then move the teeth slowly and gently

towards their optimum positions. But whereas conventional braces are built from stainless steel and metal wire, Invisalign products are clear plastic aligners that are less than one millimeter thick. They are also removable, which makes everyday tasks such as eating much easier—as you can probably imagine. One of the reasons why Invisalign has grown in recent years is because orthodontic work for adults is becoming much more popular. In the past, most people believed that braces could only really make a difference to your teeth as a teenager, when your teeth were still growing. But that is a myth. Braces can still move your teeth as an adult and you can still achieve the smile you want later in life. As more adult orthodontic treatments are becoming available, more people are keen to learn about the options available to them. The growth in adult orthodontic treatment has led to greater consumer demand for more flexible products that can be adapted to suit a customer’s lifestyle. For example, conventional braces may get just the same results as Invisalign aligners. But if you’ve got a big presentation with your boss next week, what would you rather be wearing: an old-fashioned metal and wire bracket or a virtually invisible aligner that you can even remove if you need to? In a nutshell, that’s why most adults choose Invisalign. Over the years, Invisalign has developed into a successful brand with a number of products in its portfolio. There is the original, definitive Invisalign program, which this site covers in detail from treatment through to costs. Recently, however, Invisalign has also released modified versions of the original system to exploit new opportunities within the dental market. Invisalign Express is a new version of the Invisalign system which is designed to correct minor orthodontic issues in short timescales. Invisalign Teen is the program that Invisalign has designed specifically for teenagers. It includes a number of modifications that make it easier for teenagers and parents to manage the treatment and therefore achieve the desired results. For a long time now Orthodontists and patients have wanted to correct teeth inconspicuously and without the use of fixed dental brackets. New technology has turned this dream into reality; the new type of treatment is called Invisalign (Fig. 24.1) (Invisible/Align) Technique.

History of Invisalign

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the PVS impressions and to record treatment changesor modifications immediately in a digital format. Adding the other 3D compartments (skeletal, facial, jaw movements and animation to the current surface map of the teeth) will greatly enhance the diagnostic and treatment capabilities of this appliance. Thus the clinician must have indepth understanding of the biomechanics, biology, periodontal concerns and optimal therapeutic occlusion achieved during orthodontic treatment to successfully plan and use this appliance. FABRICATION OF INVISALIGN

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Fig. 24.1: Invisalign appliance

Align Technologies introduced Invisalign (invisible/align) in 1999. Invisalign incorporates a series of invisible (clear) plastic aligners that fit comfortably over teeth and are designed to move teeth gradually into the desired position. Invisalign aligners are manufactured at the align technologies dental laboratory using computeraided design/computer-aided manufacturing (CAD/CAM) processes. PHILOSOPHY OF INVISALIGN Invisalign takes the principles of Kesling, Nahoum, and Raintree Essix even further, using cter-aided-design-computer-aidedmanufacture (CAD-CAM) technology combined with laboratory techniques to fabricate a series of custom appliances that are esthetic and removeable, and that can move teeth from beginning to end. The Invisalign system has been tested in university clinical trials and is available to public. There are currently certain limitations to this appliance in terms of cost, case selection, experienced required for computer treatment planning, difficulty obtaining certain tooth movements and lack of potential in cases involving mixed dentition or impacted teeth. However as the number of clinicians using this appliance increases more information will be available to evaluate the risks and benefits of this system. A great help in the future will be to use one of the emerging intraoral scanning devices to replace

The orthodontist submits the following to align technology: • A set of a polyvinyl siloxane impressions • A centric occlusion bite registration • A panaromic radiograph • A lateral cephalometric radiograph • Photographs. The impressions are poured up in dental plaster and then placed in a tray and encased with epoxy and urethane. The impressions are inspected by the laboratory to ensure that the patients dentition has been fully captured. The tray is placed into a destructive scanner (Figs 24.2A and B) using computed tomography. The scanners rotating blades makes numerous passes over the epoxy encased models removing a thin layer with each pass. A computer linked with a scanner then assembles the scanned information to create a three-dimensional rendering of the models. After the bite has been established, based on the clinician’s treatment plan technicians generate a virtual correction of malocclusion that is then reviewed by the clinician this process is called the Clin-Check. The software cuts the virtual models and separates the teeth allowing them to be move individually (Fig. 24.3). A virtual gingival is placed along the gingival line of the clinical crown to serve as the margin for the manufacturing of the aligners (Fig. 24.4). After final approval the treatment sequence is divided into a series of algorithmic stages. Each stage has maximum tooth movement potential of 0.25 mm/appliance. Models of each stage of treatment are made by having the computer direct their fabrication in a process called Stereolithography (Figs 24.5A to C).

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History of Orthodontics

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These models are then used to fabricate the aligners on a Biostar pressure molding machine (Fig. 24.6). The aligners are trimmed and laser etched with the patients (Fig. 24.7). • Patients initial • Case number • Aligner number • And arch upper/lower. They are then disinfected, packaged, and shipped to the doctor’s office. If for whatever

A

reason the aligners appear not to be achieving the treatment goals (compliance, difficult movements etc) a midcourse correction protocol can be initiated. Mid course correction involves new impressions and a new clean check which is send to the clinician within 2 weeks. A new series of aligners are constructed and send to the clinician. At the end of the treatment, the clinician may also be able to initiate a case refinement for detailing and final corrections if needed.

Fig. 24.3: Cutters separate teeth

B Figs 24.2A and B: (A) Destructive scanner; (B) 3D Generated computer model

A

B

Fig. 24.4: Placement of virtual gingiva

C

Figs 24.5A to C: (A) Stereolithography machines; (B) Stereolithography models; (C) Aligners

History of Invisalign

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Fig. 24.6: Biostar machine

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Fig. 24.8: The principle of stereophotolithography applied to the rapid prototyping of 3D objects

Fig. 24.7: Stereolithographic models

PRINCIPLE OF STEREOPHOTOLITHOGRAPHY Principle A system able to create 3D objects of any complexity by successive layers (slices). Each slice is produced by action of a laser light on a liquid material. This 2D shape of the solid slice is obtained by the movements of the laser, commanded by a computer. The precision is defined by the thickness of each slice (Fig. 24.8). The process called stereophotolithography (SPL) has been developed in the 90’s by Laser 3D (Nancy, France), based on the French Patent No. 84 11 241 (CNRS- July 84 (Fig. 24.9)). SUMMARY OF THE INVISALIGN TECHNIQUE The technique for using the invisalign system is as follows: • The clinician sends a rubber base impression of maxillary and mandibular arches to align technologies laboratories along with patient facial photograph, radiographs and a detailed treatment plan.

Fig. 24.9: Diagram of a typical stereophotolithograhy system, according to Kristi S Anseth, Dept Chem. Eng. Univ. of Colorado at Boulder

• The impression is inspected by the laboratory to ensure that patient’s dentition has been fully captured. Then the impression is scanned using computer tomography to create a highly accurate and detailed three-dimensional study model. • Based on the clinician’s treatment plan technicians generate a virtual correction of the malocclusion that is than reviewed by the clinicians. This process is called clin-check. • The clinician reviews the planned corrections and if necessary, sends any revisions to align technology. The final step of clin-check must be approved by the treating clinician. • After final approval, the treatment sequence is divided into a series of algorithmic stages. Each

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History of Orthodontics

stage has a maximum tooth movement potential of 0.25 mm per appliances. • Models of each stage of treatment are made by process called stereolithography Individual appliances (aligners) are made from the computer-generated models of each stage. • A typical invisalign treatment requires 20 to 30 aligners for the maxillary and mandibular arches. • In most of the cases, treatment with invisalign is done in less than a year; however, treatment time depends on the specific alignment problem.

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INDICATIONS OF INVISALIGN According to researchers and align technologies, invisalign can be used to correct the following types of mild malocclusions: 1. Malocclusion with mild crowding cases. 2. Malocclusion with mild spacing case. 3. In cases mild relapse – after traditional braces have been removed, when some relapsing tooth movement has occurred. ADVANTAGES OF INVISALIGN 1. Improved esthetics compared to fixed orthodontic appliance and ability to remove the appliance. 2. Invisalign patients showed no measurable root resorption. 3. It gives the patient an esthetic choice in their orthodontic treatment. DISADVANTAGES OF INVISALIGN 1. Fabrication of the aligners is a very time consuming and tedious process that probably would not be practical day to day orthodontic practice. 2. Severe derotations, complex extrusions and large translations are less predictable with invisalign and may require auxiliary treatment. LIMITATIONS OF INVISALIGN 1. All permanent teeth should be fully erupted for treatment using invisalign as it is difficult to achieve retention of the appliance on short clinical crowns.

2. The treatment procedures do not allow for continued eruption of teeth, or significant dental arch changes during growth that may occur during the mixed dentition phase. 3. There is currently no capability to incorporate basal orthopedic change with this appliance system, thus restricting it to malocclusions requiring pure dental movements. 4. Unlike fixed or removable appliances, the treatment plan cannot be changed once the appliance series has begun. If change in treatment is desired the current series may be completed and a new plan and appliances are made or the current series may be stopped. 5. The inability to integrate hard and soft tissues of the head into the computer treatment thus there is no direct indication of where teeth are in relation to basal bone or in relation to the lips or other soft tissues of head. 6. Invisalign is generally not recommended in treating more complicated malocclusions such as severe deep bite, anterior-posterior corrections greater than 2mm, uprighting severely tipped teeth and closure of premolar extraction spaces. PROCEDURE OF TREATMENT WITH THE INVISALIGN First Evaluation • Orthodontist evaluates and creates a program of treatment. • Records and impressions of arches are taken. Invisalign Aligners Made and Delivered • A CT-scan (Computed Tomography or CATscan), is made from your dental impressions that produces an extremely accurate, 3D digital model of your teeth. • CAD (Computer-aided design) software is then used to simulate the movement of your teeth during treatment. • The treatment plan are reviewed, modified, and approved before the aligners are created. • Invisalign then uses advanced stereolithography (SLA) technology to build precise moulds of teeth at each stage of treatment. • Individualized, custom-created clear aligners are made from these models and sent to orthodontist.

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History of Invisalign

Wearing of Invisalign (Fig. 24.10) • Visits are made to orthodontist for adjustments and to check progress on a monthly basis. • At regular intervals, a new set of custommolded clear aligners are received to continue the straightening process. The total number of clear aligners is specific to you, determined by orthodontist for the course of treatment.

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BENEFITS OF INVISALIGN 1. Invisible thus no unwarranted attention to your mouth. 2. Removable thus easy to eat, brush and floss. 3. No brackets to catch food or plaque. 4. Healthier gums from properly aligned teeth that help gums to “fit” tighter around each tooth. 5. Easier cleanings in maintaining a good oral hygiene program that reduce chances of plaque build-up, tooth decay and periodontal disease. CARE OF TEETH WITH INVISALIGN 1. Teeth and the aligners would need to be kept cleaned every day if the teeth and gums are to be healthy during and after orthodontic treatment. 2. Follow orthodontist directions on how often to brush, how often to floss and use of other cleaning aids to help maintain good dental health. Like brackets and arch wires are to braces, Invisalign aligners move teeth through the appropriate placement of controlled force on

the teeth. The principal difference is that Invisalign not only controls forces, but also controls the timing of the force application. At each stage, only certain teeth are allowed to move, and these movements are determined by the orthodontic treatment plan for that particular stage. This results in an efficient force delivery system.

STUDY 1 OUTCOME ASSESSMENT OF INVISALIGN AND TRADITIONAL ORTHODONTIC TREATMENT COMPARED WITH THE AMERICAN BOARD OF ORTHODONTICS OBJECTIVE GRADING SYSTEM Garret Djeu,a Clarence Shelton,b and Anthony Maganzinic New York, NY Introduction This treatment-outcome assessment objectively compares Invisalign (Align Technology, Santa Clara, Calif) treatment with braces. Methods This study, a retrospective cohort analysis, was conducted in New York, NY, in 2004. Records from 2 groups of 48 patients (Invisalign and braces groups) were evaluated by using methods from the American Board of Orthodontics Phase III examination. The discrepancy index was used to analyze pretreatment records to control for initial severity of malocclusion. The objective grading system (OGS) was used to systematically grade posttreatment records. Statistical analyses evaluated treatment outcome, duration, and strengths and weaknesses of Invisalign compared with braces. Results

Fig. 24.10: Wearing invisalign appliance

The Invisalign group lost 13 OGS points more than the braces group on average, and the OGS passing rate for Invisalign was 27% lower than that for braces. Invisalign scores were consistently lower than braces scores for buccolingual inclination, occlusal contacts, occlusal relationships, and overjet. Invisalign’s OGS scores were negatively correlated to initial overjet, occlusion, and buccal posterior crossibite. Invisalign patients finished

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History of Orthodontics

4 months sooner than those with fixed appliances on average. P _ .05 was used to determine statistically significant differences. Conclusion According to the OGS, Invisalign did not treat malocclusions as well as braces in this sample. Invisalign was especially deficient in its ability to correct large anteroposterior discrepancies and occlusal contacts. The strengths of Invisalign were its ability to close spaces and correct anterior rotations and marginal ridge heights. This study might help clinicians to determine which patients are best suited for Invisalign treatment (Am J Orthod Dentofacial Orthop 2005;128.

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STUDY 2 HOW WELL DOES INVISALIGN WORK? A PROSPECTIVE CLINICAL STUDY EVALUATING THE EFFICACY OF TOOTH MOVEMENT WITH INVISALIGN Neal D. Kravitz,a Budi Kusnoto,b Ellen BeGole,c Ales Obrez,d and Brent Agrane South Riding, Va, White Plains, Md, and Chicago, Ill Introduction The purpose of this prospective clinical study was to evaluate the efficacy of tooth movement with removable polyurethane aligners (Invisalign, Align Technology, Santa Clara, Calif). Methods The study sample included 37 patients treated with Anterior Invisalign. Four hundred one anterior teeth (198 maxillary and 203 mandibular) were measured on the virtual treat models. The virtual model of the predicted tooth position was superimposed over the virtual model of the achieved tooth position, created from the posttreatment impression, and the 2 models were superimposed over their stationary posterior teeth by using Tooth Measure, Invisalign’s proprietary superimposition software. The amount of tooth movement predicted was compared with the amount achieved after treatment. The types of movements studied were expansion, constriction, intrusion, extrusion, mesiodistal tip, labiolingual tip, and rotation.

Results The mean accuracy of tooth movement with Invisalign was 41%. The most accurate movement was lingual constriction (47.1%), and the least accurate movement was extrusion (29.6%)— specifically, extrusion of the maxillary (18.3%) and mandibular (24.5%) central incisors, followed by mesiodistal tipping of the mandibular canines (26.9%). The accuracy of canine rotation was significantly lower than that of all other teeth, with the exception of the maxillary lateral incisors. At rotational movements greater than 15°, the accuracy of rotation for the maxillary canines fell significantly. Lingual crown tip was significantly more accurate than labial crown tip, particularly for the maxillary incisors. There was no statistical difference in accuracy between maxillary and mandibular teeth of the same tooth type for any movements studied. Conclusion In this prospective clinical study evaluating the efficacy of tooth movement with Invisalign, the following conclusions were made: 1. The mean accuracy of tooth movement with Invisalign was 41%. The most accurate tooth movement was lingual constriction (47.1%). The least accurate tooth movement was extrusion (29.6%). The mandibular canine was the most difficult tooth to control. 2. Maxillary and mandibular canines achieved approximately one-third of the predicted rotation. The accuracy of canine rotation was significantly lower than the rotation of all other teeth, with the exception of the maxillary lateral incisors. At rotational movements greater than 15°, the accuracy for the maxillary canines was significantly reduced. 3. With the exception of canine rotation, no tooth was significantly less accurate in movement. 4. Lingual crown tip was significantly more accurate than labial crown tip, particularly for the maxillary incisors. 5. The severity of pretreatment overjet might influence the accuracy of anterior tooth movement with Invisalign. 6. There was no statistical difference in accuracy between maxillary and mandibular teeth of the same type for any tooth movement studied. These results indicate that we still have much to learn regarding the biomechanics and

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History of Invisalign

efficacy of the Invisalign system. Clinicians who prescribe Invisalign treatment should fully recognize its limitations and commit themselves to providing the gold standard of care for their patients. Providing quality care, regardless of the treatment modality, is only way to truly be a premiere provider.

STUDY 3

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RETAINING ALIGNMENT CHANGES WITH INVISALIGN Kuncio D, Maganzini A, Shelton C, et al: Invisalign and traditional orthodontic treatment postretention outcomes compared using the American Board of Orthodontics objective grading system. Angle Orthod 77:864-869, 2007. Relapse of orthodontic cases, while extensively studied, remains poorly understood. In this study, while both techniques produced acceptable initial results, cases treated with conventional braces were more stable over time. Retention times were comparable but changes in resultant treatment forces were more frequent with Invisalign than with fixed appliances.

STUDY 4 STRUCTURAL CONFORMATION AND LEACHING FROM IN VITRO AGED AND RETRIEVED INVISALIGN APPLIANCES Susan Schuster, DDS,a George Eliades, DDS, DrDent,b Spiros Zinelis, PhD,c Theodore Eliades, DDS, MS, DrMed, PhD,d and T. Gerard Bradley, BDS, MSe Milwaukee, Wis, and Athens, Greece The objectives of this study were to investigate the structure of Invisalign appliances (Align Technology, Santa Clara, Calif) after intraoral exposure, and to qualitatively and quantitatively characterize the substances leached from the aligners after accelerated in vitro aging. Samples of Invisalign appliances were randomly selected from 10 patients before intraoral placement and after retrieval, and the prepared specimens were subjected to (1) brightfield optical reflection microscopy to study the surface morphology; (2) Fourier transform infrared microspectroscopy to characterize the in vivo changes in molecular composition induced on appliance surfaces, (3) scanning electron

microscopy and energy dispersive X-ray microanalysis to identify the elemental composition of integuments formed on the surface, and (4) Vickers hardness (HV200) testing. Another set of reference and retrieved appliances was subjected to artificial aging for 2 weeks, and the extracts were subjected to gas chromatography-mass spectroscopy. The retrieved appliances demonstrated substantial morphological variation relative to the as-received specimens involving abrasion at the cusp tips, adsorption of integuments, and localized calcification of the precipitated biofilm at stagnation sites. Buccal segments of retrieved appliances showed an increase in hardness, which might be attributed to mastication-induced cold work; however, the clinical implication of this effect on mechanotherapy is unknown. In vitro aged and retrieved appliances were found to leach no traceable amount of substances in an ethanol aging solution. (Am J Orthod Dentofacial Orthop 2004;126:725-8). Conclusion Retrieved Invisalign appliances demonstrate substantial morphological variation in relation to new specimens, involving abrasion at the cusp tips, adsorption of integuments at stagnation sites, and localized calcification of the biofilm developed during intraoral service. An increase in hardness of the buccal segments of the retrieved appliances was found; this could mainly be attributed to cold work during mastication. The clinical implication of this effect in the force delivery of the appliance requires further study. In vitro aged appliances were found not to release traceable monomers or byproducts after immersion in an ethanol-water solvent. The aging pattern of these appliances intraorally involves abrasive wear arising from mastication, and, thus, no definitive consensus on their reactivity and biological properties can yet be established.

STUDY 5 CYTOTOXICITY AND ESTROGENICITY OF INVISALIGN APPLIANCES Theodore Eliades,a Harris Pratsinis,b Athanasios E. Athanasiou,c George Eliades,d and Dimitris Kletsase Thessaloniki and Athens, Greece

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Introduction

Materials and Methods

Our purpose was to study the in-vitro cytotoxic and estrogenic properties of Invisalign appliances (Align Technology, Santa Clara, Calif). Methods: Three sets, each consisting of a maxillary and a mandibular appliance, of as-received aligners were immersed in normal saline solution for 2 months. Samples of eluents were diluted to 3 concentrations (5%, 10%, and 20% vol/vol) and tested for cytotoxicity on human gingival fibroblasts and estrogenicity by measuring their effect on the proliferation of the estrogenresponsive MCF-7 breast cancer cells. All assays were repeated 4 times for each maxillary and mandibular set, and the results were analyzed with 2-way analysis of variance (ANOVA) with appliance and concentration serving as predictors at the .05 level of significance; differences among groups were investigated with the Tukey test.

The compliance indicators in the Invisalign Teen aligners were tested for color resistance in various aqueous models with no saliva involved.

Results

Results Color fading was observed as a function of time, pH, and temperature while compliance indicators were stored in drinking water or sour soft drinks and in conjunction with the use of cleaning tablets and a dishwasher. The findings of color fading were consistent with the color changes observed when the aligners were being worn by patients. Color fading, notably as observed in connection with acidic soft drinks and cleaning techniques, introduces uncertainty into the assessment of actual patient compliance, as reflected by the fading colors of compliance indicators. Conclusion

There was no evidence of cytotoxicity on human gingival fibroblasts and no stimulation of proliferation of the MCF-7 cell line at any concentration, indicating no estrogenicity of aligner eluents. Conclusions: The use of Invisalign appliances did not seem to induce estrogenic effects under the conditions of this experiment. (Am J Orthod Dentofacial Orthop 2009;136:100-3). Conclusion No cytotoxic or estrogenic activity of Invisalign appliances was documented in this in-vitro assay, which used a standard model for the assessment of estrogenicity of materials.

STUDY 6 COLOR FADING OF THE BLUE COMPLIANCE INDICATOR ENCAPSULATED IN REMOVABLE CLEAR INVISALIGN TEEN ALIGNERS Timm Cornelius Schotta; Gernot Go¨ zb

Compliance indicators are not immune to simple intentional or unintentional manipulations. Therefore, they can best show an estimate of wear time but cannot be recommended as objective wear-time indicators. (Angle Orthod. 2011;81:185–191).

STUDY 7 A COMPARISON OF TREATMENT IMPACTS BETWEEN INVISALIGN ALIGNER AND FIXED APPLIANCE THERAPY DURING THE FIRST WEEK OF TREATMENT Kevin B. Miller,a Susan P. McGorray,b Randy Womack,c Juan Carlos Quintero,d Mark Perelmuter,e Jerome Gibson,f Teresa A. Dolan,g and Timothy T. Wheelerh Rock Hill, SC, Gainesville and Miami, Fla, Glendale, Ariz, Louisville, Ky, and San Antonio, Tex Introduction

Objective To evaluate the color fading in aqueous solutions of the blue dot wear-compliance indicators of the Invisalign TeenH System outside the oral cavity.

The aim of this study was to evaluate the differences in quality of life impacts between subjects treated with Invisalign aligners (Align Technology, Santa Clara, Calif) and those with

History of Invisalign

fixed appliances during the first week of orthodontic treatment. Methods: A prospective, longitudinal cohort study involving 60 adult orthodontic patients (33 with Invisalign aligners, 27 with fixed appliances) was completed by using a daily diary to measure treatment impacts including functional, psychosocial, and painrelated outcomes. A baseline survey was completed before the start of treatment; diary entries were made for 7 consecutive days to measure various impacts of the subjects’ orthodontic treatment over time. The data were then analyzed for differences between treatment modalities in terms of the subjects’ reported impacts from their orthodontic treatment.

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Results The baseline mean values did not differ between groups for pain reports (P _ .22) or overall quality of life impact (P _ .51). During the first week of treatment, the subjects in the Invisalign group reported fewer negative impacts on overall quality of life (P _.0001). The Invisalign group also recorded less impact in each quality of life subscale evaluated (functional, psychosocial, and pain-related, all P _.003). The visual analog scale pain reports showed that subjects in the Invisalign group experienced less pain during the first week of treatment (P _.0001). The subjects in the fixed appliance group took more pain medications than those in the Invisalign group at days 2 and 3 (both P _.007). Conclusion Adults treated with Invisalign aligners experienced less pain and fewer negative impacts on their lives during the first week of orthodontic treatment.

OTHER STUDIES SCIENTIFIC STUDIES In a systematic review of the literature, published in the Journal of the American Dental Association in 2005.Drs. Manual Lagravere and Carlos FloresMir were unable to draw strong conclusions about

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the effectiveness of the Invisalign system. They pointed to the need for randomized clinical trials. Since this paper, more studies about the clinical effectiveness have been published; for example in the UK, Dr Paul Humber has analyzed 100 backto-back Invisalign cases. Assessing the patients after two sets of aligners, he found that 94% of the dentitions had achieved the objectives set. In the USA, Akhlaghi and colleagues compared treatment with the invisalign system with treatment with conventional braces and concluded that “conventional fixed appliances achieved better results in the treatment of Class I mild crowding malocclusions” In a comparison of outcomes between the two approaches, Kuncio et al reported that the Invisalign group displayed greater relapse saying “the mean alignment of the Invisalign group was superior to the Braces group before and after the retention phase, but these differences were not statistically significant. Therefore, even though the Invisalign cases relapsed more, they appear to have the same, if not better, overall alignment scores.” In a larger study Djeu and colleagues had similar findings to Akhlaghi above and concluded that “Invisalign was especially deficient in its ability to correct large anteroposterior discrepancies and occlusal contacts”. They felt that “The strengths of Invisalign were its ability to close spaces and correct anterior rotations and marginal ridge heights.” They added “Invisalign patients finished 4 months sooner than those with fixed appliances on average.” Furthermore, work at NYU/Buffalo University by Dr Omar Fetouh was published in 2009 where 67 patients were studied, half of whom were treated with Invisalign and half with fixed appliances. He concluded that ‘There was no statistical significant difference between the scores of the Invisalign group and Braces group for Alignment, Occlusal Relationship and Interproximal Contacts. The Invisalign group had higher scores in Marginal ridges, Bucco-lingual inclination, Occlusal Contacts, and Overjet than the Braces group.’ His conclusion was that Invisalign can treat mild malocclusions ‘as efficiently, if not better, as braces.’

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History of Molar Distalization in Orthodontics • History of Molar Distalization • Indications for Molar Distalization • Contraindications of Molar Distalization • An Ideal Intraoral Molar Distalization Appliance should meet the following Criteria • Mechanism of Action of Distalizing Appliances • Pendulum Appliance • Pend-X Appliance • M-pendulum Appliance • Pendulum F Appliance • Jones Jig

• Intermaxillary Class II Malocclusion Correction Appliances • Vertical Holding Appliance • Removable Molar Distalization Splint • Symmetric Distalization with a TMA Transpalatal Arch • Tube Plates for Distalization of Molars • Cetlin Appliance • Anchorage Need • Extraoral Force • The Force Applied • The Lokar Appliance

Whenever there is space deficiency, the methods of gaining space that strikes to our mind first are, extraction, expansion and stripping. Angle, proposed expansion of dental arches for nearly every patient and extraction for orthodontic purpose was not necessary for stability of results or for aesthetics. He believed that when teeth could be saved by dental treatment, extraction of teeth for orthodontic purpose seemed particularly inappropriate unacceptable. In 1930’s, Charles Tweed observed relapse after non-extraction expansion treatment and decided to retreat with extraction. In recent years, the percentage of patients having extraction as a part of orthodontic treatment has decreased considerably as experiments has shown that premolar extraction does not necessarily guarantee stability of teeth alignment. Proximal stripping also has its own limitation.

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• • • • • • • •

K-loop Molar Distalizer The Distal Jet Appliance The Crozat Appliance Molar Distalization by Magnets The Magnets The Klapper Superspring Herbst Appliance The Mandibular Anterior Repositioning Appliance (MARA) • Saif Springs • The ‘Fastback’ Appliance for Molar Distalization • Features of Fast Back Appliance

HISTORY OF MOLAR DISTALIZATION The concept of ‘distal driving’ of the maxillary posterior teeth has a long orthodontic history in 1920s. Class II elastic treatment was thought to be an easy and effective tool but early cephalometric studies in 1940s showed little or no distal movement of upper molars. Thus headgears were reintroduced as means of moving upper molars back. These extra oral appliances were heavily dependent on patient cooperation, forces generated were high and intermittent causing severe patient discomfort and prolonged treatment time. To overcome these difficulties, more recently several intra oral appliances employing palatal anchorage have been used to produce distal movement of upper molars. Distalization mechanics has found many supporters in its

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History of Molar Distalization in Orthodontics

quarters since it provides the arch with increase length which may correct arch relationship as well as do away with extraction and loss of tooth. In some cases the operator gets bonus of achieving expansion or molar derotation also. • Molar distalization, in recent years is evolved as an alternative method of gaining space to conventional methods where ever is indicated. • Kingsley was the first person to try to move the maxillary teeth backwards in 1892 by means of headgear. • Oppenheim advocated that position of mandibular teeth as being the most correct for individual and use of occipital anchorage for moving maxillary teeth distally into correct relationship without disturbing mandibular teeth. In 1944, he treated a case with extra-oral anchorage for distalizing maxillary molar. • Renfroe (1956) reported that lip bumper primarily devised to hold hypertonic lower lip caused a distal movement of lower molars sufficient to change class I to Class II. • Gould (1957) was first person to discuss about unilateral distalization of molars with extraoral force. • Kloehn (1951) described the effects of cervical pull headgear. • Graber T-M. (1969) extracted the maxillary II molar and distalized the first molar to correct class II div.1. Non-extraction treatment plans for angle class II malocclusions often require the distal movement of maxillary molars in the initial stage of treatment to convert the class II molar relationship to a class I molar relationship. Most traditional approaches to molar distalization including extra-oral traction through use of a headgear, Wilson distalizing arches, spring appliances and inter-maxilalry elastics with sliding jigs, require considerable patient compliance to be successful. With heightened awareness of balance and harmony of the facial profile combined with a need to treat patients with marginal space discrepancies, a variety of methods have been proposed to move molars distally with reduced dependence on patient co-operation. More recently, the subjectivity and problems of predicting patient behavior have led many clinicians to devise appliances that minimized reliance on the patient and that are under the

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control of the clinician. Relying on the patient’s willingness to wear an appliance consistently may result in increased treatment time, a change of treatment plan or both. In recent years, appliances largely independent of patient compliance increasingly have been used for maxillary molar distalization. INDICATIONS FOR MOLAR DISTALIZATION In a Growing Child • To relieve mild crowding • Causes permanent increase in arch-length of about 2 mm on each side. Late Mixed Dentition • When lower E space – utilized for relief of anterior crowding • Upper molars distalized to get a class I relation • Class I malocclusion—with highly/labially placed canine/impacted canine • Lack of space for eruption of premolars due to mesial migration of permanent first molars • Good soft tissue profile • Borderline cases • Mild-to-moderate space discrepancy with missing 3rd molars/2nd molars not yet erupted • Axial inclination : Mesially angulated upper molars • Normal or hypodivergant growth pattern • Late mixed dentition with mild crowding of anteriors. CONTRAINDICATIONS OF MOLAR DISTALIZATION • Profile: – Retrognathic profile. • Functional: – Numerous signs and symptoms of temperomandibular joint – Posteriorly and superiorly displaced condyles. • Skeletal: – Class II skeletal – Skeletal open – Excess lower face height – Constricted maxillary arch – Dolicocephalic growth pattern. • Dental: Class I or III molar relation.

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• Dental open bite Maxillary first molar distally inclined. AN IDEAL INTRAORAL MOLAR DISTALIZATION APPLIANCE SHOULD MEET THE FOLLOWING CRITERIA

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1. Minimal need for patient compliance. 2. Acceptable esthetics and comfort. 3. Minimal loss of anterior anchorage (as evidenced by axial proclination of the incisors. 4. Bodily movement of molars to avoid undesirable side-effects, lengthening of treatment and unstable results. 5. Minimal chair time for placement and reactivations. Advantage No patient cooperation was necessary to obtain molar movement.

• • • • • • • • • • • • • • • • • • • • •

Crozat appliance Crickett appliance CETLIN appliance Removable molar distalization splint Modified Nance Lingual appliance Non-extraction treatment (lip bumper) Molar distalization with magnets Transpalatal arch Use of Super elastic NiTi Double loop niti The Pendulum appliance Jones Jig C-space regainer Lokar appliance Intra oral bodily molar distalizer (IBMD) Maillary distalizing system (MDS) Fixed piston appliance The K-loop appliance The distal jet Using Implants Fixed functional appliances.

MECHANISM OF ACTION OF DISTALIZING APPLIANCES

PENDULUM APPLIANCE

• Passive 0.016 × 0.22 inch wire with stops that abut the distal wings of premolar brackets is inserted, and the coils are placed on the wire between first premolars and molars. The coils are activated 8 to 10 mm by compressing and maintaining them against the molars by crimpable hooks. • Since the reaction force of the coil moves the wire anterior, the function of the stop against premolar bracket is to ensure that the wire cannot move past first premolars, thus placing reaction force on Nance appliance. To enhance anchorage, 0.018 inch uprighting spring is placed in the vertical slot of the premolar brackets directing the crowns distally. • When class II elastics are attached, rectangular wire with 10 degree of incisor lingual root torque is inserted in the mandibular arch to maintain lower incisor position. Molar position is maintained by inserted of 0.016 x 0.022 inch wire with stops that about the molar tubes. Various types of molar distalization appliances in orthodontics are listed below and few of them are described in this chapter: • Headgears • Wilson Bimetric arch design • ACCO

This appliance first described by Hilgers in 1992 uses a large Nance button in the palate for anchorage and 0.032-inch TMA springs (Ormco Corporation) that delivers a distalizing force to the upper molars. The springs insert into lingual sheaths on the palatal surface of the band. The anterior portion of the appliance is retained with premolar bands, which are joined to the appliance using a retaining wire. Occlusally-bonded rests on the primary molars or second premolars add to the retention. If expansion of the upper arch is indicated, then a midline screw can be added to the appliance. This version of the appliance is known as the Pend-X appliance. Byloff and Darendeliler (1997) showed that the appliance moved molars distally without creating bite opening, but the molars did tend to tip. At the incisal edge was the anchorage loss was measured at 0.92 mm (SD ±0.67). Second premolar anchorage loss was measured at a mean of 1.63 mm (SD ±1.23), but distal movement of the molar represented 71 per cent of the space opened. If molar uprighting bends were incorporated into the appliance it reduced the tipping, but increased the anchorage loss at the premolars by 0.61 mm and the incisal edge by 0.62 mm (Byloff et al., 1997).

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History of Molar Distalization in Orthodontics

Ghosh and Nanda (1996) also found that the pendulum appliance is a reliable method for distalizing maxillary molars at the expense of moderate anchorage loss. The advantages of the appliance lies in its minimal dependence on patient’s compliance, ease of fabrication, one time activation, adjustment of the springs, if necessary to correct minor transverse and vertical molar positions, and patient’s acceptance. The mean maxillary molar movement was 3.4 mm with a distal tipping of 8.4 degrees. There was, however, 2.5 mm mesial movement of the first premolar, which represents some anchorage loss. Thus, for every millimeter of distal molar movement, the premolar moved mesially 0.75 mm. Hilgers (1992) reports that when the appliance is placed before the eruption of the second molars, two-thirds of the tooth movement is molar distalization, one-third is experienced as forward shift of the anchor bicuspids. If placed after eruption of the second molars, the experience tends to be reversed, one-third distal movement of the first molar, and two-thirds anchorage slip. Advantages • • • •

Minimal dependence on patient compliance Ease of fabrication One time activation Adjustment of the springs if necessary to correct minor transverse and vertical molar positions. • Patient’s acceptance. • Unilateral class II corrections. • Used to regain space lost through mesial drifting of the upper first molars because of either early loss of second deciduous molars or impaction of first molars under distal crown contour of the deciduous molars. Rapid distalization of upper first molars and stabilization with an insta Nance provide space for the erupting second bicuspids. Disadvantages James J Hilgers in 1992 introduced an appliance for class II correction in non-compliant patients. The “pendulum appliance” is a hybrid that uses large Nance acrylic button in the palate for

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anchorage along with 0.032" TMA springs that deliver light, continuous force to the upper first molars without affecting the palatal button. Thus, the appliance produces a broad swinging or pendulum of force from the midline of the palate to the upper molars. PEND-X APPLIANCE • In cases with severe narrowing of maxillary posterior segments, if expansion of upper arch is needed, a mid palatal jack screw can be incorporated into the center of the Nance button. • The screw is activated one-quarter turn every three days, after a week or so for patient adjustment, to produce a slow, stable expansion. • The resulting activation is usually sufficient not only to correct any transverse discrepancies, but also to control molar rotation during distalization. M-PENDULUM APPLIANCE Giuseppe Scuzzo in 1999 introduced Mpendulum: • In this horizontal pendulum loops are inverted, it will allow bodily movement of both the roots and crowns of the maxillary molars. Once the distal molar movement has occurred, the loop can be activated simply by opening it. • The activation produces buccal/distal up righting of the molar roots and thus a true bodily movement rather than a simple tipping or rotation. • Pendulum springs are activated to 40–45o, resulting in about 125 g of force on each side. This activation is repeated until the desired distalization of the molars is obtained. Advantages • • • • •

True bodily molar movement Minimal dependence on patient compliance Ease of fabrication Little need for reactivation Patient’s acceptance. An intra-maxillary anchorage unit is needed to counteract the reactive forces and moments in molar distalization.

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History of Orthodontics

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Anchorage Design of the M-pendulum Appliance • The anchorage block consists of a Nance palatal button and anchoring teeth in the same dental arch. The acrylic button fits tightly against the palatal mucosa in the region of the palatal rugae and is linked to the teeth with occlusally bonded onlays. After placement of the pre-activated pendulum springs, the anchorage unit is designed to counteract the reactive forces and moments. • The anchorage effect of the anterior palatal plate to the resilient palatal mucosa might be due to hydrodynamic interactions. Additional vertical stabilization might result from tongue pressure while swallowing. Anchorage value of the soft tissue supported Nance holding arch should not be overestimated. • The anchorage mainly depends on the dental anchorage quality of the teeth. The resistance potential of these anchorage teeth is determined by the size of the anchorage relevant surfaces and thus by the number of teeth involved, by root topography and the attachment level and by the bone structure and the desmodontal reactive state. • The bone structure and attachment level is constant among children and adolescents treated with pendulum appliance but differences might occur with respect to the number of teeth, root topography and desmodontal reactive state. Number of Anchorage Teeth • Hilgers used only anterior part of the appliance, using bands on maxillary first premolars or deciduous molars and a holding arch to the Nance button. He observed that after placing the springs, Nance buttons tended to lift. So the recommended that supporting elements should be bonded occlusally to the maxillary second premolars or second deciduous molars for additional stability. Additional bonding of occlusal on lays to the canines to obtain additional anchorage support is also recommended. • The reactive segment should consist of as many anchorage teeth as possible, which are combined to form a multi-rooted anterior anchorage unit with occlusal onlays and the

Nance button and permit uniform periodontal pressure distribution. Anchorage Quality of Deciduous Molars and Premolar Root Topography • The desmodontal anchorage quality of the anchoring teeth depends largely on their root surfaces and root topography. • Even if root surface of deciduous molars and premolars are identical, anchorage quality of deciduous molars undergoes a constant decrease during physiologic resorption resulting in imbalance in the favor of the premolars. • The results of this study show that extent and quality of molar distalization are better and side-effects are less pronounced in the anchorage and the incisor region if premolars alone are used for anchorage. • It is advisable to perform an initial test for increased tooth mobility when using dec. molars for anchorage, to avoid having to remove the appliance prematurely when the anchorage quality is overestimated. • A panoramic radiograph provides information on the extent of root resorption of dec. molars and indirectly quality of such teeth for anchorage purposes during pendulum appliance therapy. Desmodontal Reactive State, Potential Causes of Reduced Anchorage • The primarily unmoved tooth in a desmodontal resting state offers the best tissue resistance. • Initial leveling increases the proliferation rate of cells relevant to the remodeling process in the anchorage unit and increases readiness for reactive movement. Therefore initial leveling should not be performed in the region of the anchorage unit when placing pendulum appliance. • Omission of Nance anterior palatal plate also leads to increased loss of anchorage. Potential Measures for Increased Anchorage When an end osseous implant is used in the region of the hard palate or miniscrews, stationary intraoral anchorage can be achieved without teeth being incorporated. The fixing of pendulum appliance

History of Molar Distalization in Orthodontics

to an Osseo integrated palatal implant of the ortho system not only represents a significant improvement in anchorage quality during molar distalization but also permits stationary anchorage with a transpalatal arch during the subsequent distal guidance of premolars and canines. They are used in exceptional cases such as adults with problematic periodontal anchorage or in mixed dentitions with early loss of the decidduous molars.

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PENDULUM F APPLIANCE Favero modified pendulum appliance for lingual technique. Acrylic portion of the Nance button has a larger dimension than in other pendulum appliances and can accommodate in the anterior region a segmented wire, which is inserted in the lingual brackets of the incisors. An increase in biological anchorage quality is possible. Occlusal forces can be used therapeutically for increased anchorage if the composite on lays to which the wires are attached were formed with an occlusal relief. This method can be applied only if mandibular arch has sufficient teeth which are in stable position (i.e. no orthodontic treatment is performed simultaneously in the mandible). Drawbacks 1. Lingual tipping of molars. 2. Difficult to fabricate. JONES JIG The Jones Jig was first introduced by Richard D. Jones and J. Michael White. Jones Jig is one of the appliances which accomplish tooth movement without the need for patient compliance. The appliance uses an open coil Nickel titanium spring to deliver 70–75 g. Over a compressive range 1–5 mm to the molars. Advantages The advantages of the Jones Jig appliance are that, it can achieve class I relationship even when: • 2nd motors erupted or unerupted • In mixed and permanent dentition • Unilateral as well as bilateral distalization • Growing and non-growing patients. The appliance is also said to be a predictable, painless sand rapid method of correcting class II relationship with minimum patient co-operation.

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INTERMAXILLARY CLASS II MALOCCLUSION CORRECTION APPLIANCES Several intermaxillary fixed non-complaint appliances have been proposed and used over the past two decades. Advantages • Forward displacement of the mandible. • Backward displacement of the maxilla • Anterior force on the mandibular dentition. All above three actions and movements will bring about the correction of class II malocclusion. Disadvantages The common disadvantage of intermaxillary appliances is undesirable steepening of the occlusal plane with concomitant flaring of the lower incisors and distal tipping along with extrusion of the maxillary incisors. VERTICAL HOLDING APPLIANCE Vertical Holding Appliance is a fixed functional intra-oral distalizing appliance, as it is activated from the functional activity of the tongue. Wire used for the fabrication of this appliance: 0.040 inch wire is used for the fabrication of this appliance. Helices of Vertical Holding Appliance • Vertical holding appliance consist of four helices in its design • The two helices are placed just distal to each maxillary first molar • Other two helices are placed at the center of the appliance. V-Bend • V-bend is fabricated using 0.040 inch wire • V-bend separates the helices of VHA which are placed at the center of the appliance • V-bend portion of the wire is embedded in the acrylic button. Acrylic Button • Acrylic button is composed of self –cure acrylic material • Size of the acrylic button—size of a dime

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History of Orthodontics

• Thickness of the button—the acrylic button should be 2–5 mm away from the palate • Acrylic button contributes greater proportion as compared to the any other portion of the appliance.

Vertical holding appliance results in intrusion and distally directed force.

This method has several advantages: 1. ‘TMA’ has better shape memory and resilience than stainless steel. 2. The arch is simple to construct. 3. The system is hygienic and economic. 4. This is no anterior anchorage loss; the premolars and canines spontaneously follow the molar distally.

REMOVABLE MOLAR DISTALIZATION SPLINT

Drawbacks

Action

The removable molar distalization appliance was put forward by Dr A. Korrodi Ritto, to overcome the drawbacks of patient co-operation, needed with other removable appliances like the removable plates and headgears. For Personal Use Only Library Of School Of Dentistry.Tums

Advantages

Advantages 1. 2. 3. 4.

It is smaller than conventional removable plates. It is comfortable. Esthetics. Better patient co-operation.

Disadvantage There is more amount of molar tipping seen rather than bodily, molar distalization. Therefore the best cases for treatment with this appliance are those where the molars are already messily tipped. SYMMETRIC DISTALIZATION WITH A TMA TRANSPALATAL ARCH The intra-oral distalization methods can all produce bodily distal movement of the maxillary molars, but can also cause a mesial movement of the maxillary premolars and canines, or a proclination of the mandibular incisors when class II elastics are used. In addition, the loss of anterior anchorage often leads to relapse of the maxillary molars during the correction of canine relationship, overbite and over jet. According to Cetlin’s method, maxillary molars can be distalized unilaterally by using a Goshgarian transpalatal arch in conjunction with extra-oral traction. A toe-in-bend in the transpalatal arch applies a mesiobuccal rotation to the molar on the side of the bend and a distally directed force against the molar on the opposite side. This procedure does not cause a loss of anterior anchorage.

1. Because the ‘TMA’ is more fragile than stainless steel, the arch must be bent carefully, and fractures in the mouth are more common. 2. Since the ‘TMA’ arch rotates the anchor molar more mesiobuccally than a conventional arch does. It should be combined with a fixed orthodontic appliance using a rectangular arch-wire or a passive stainless steel wire segment between the second molar and canine on the anchor side. 3. The system can only distalize one molar at a time, and therefore is recommended for use with unilateral or slight bilateral class II molar relationships. 4. An extra-oral appliance should be worn at night to reinforce anchorage. TUBE PLATES FOR DISTALIZATION OF MOLARS Lain Benauwt explained the use of a removable appliance for distalizing the molars. These appliances were introduced as the appliances with wires sliding in tubes. Advantages 1. Retention of the appliance is very good, as the movable parts contribute to the retention (due to incorporation of Adam’s clasp). 2. It is very helpful in mixed dentition, when deciduous molars are not too retentive or are broken down or missing. 3. Unwanted displacement of teeth is minimized due to the Adam’s Clasp who holds the molar and avoids rotation. 4. An extra-oral appliance can be used along with this appliance to support and reinforce the stationary part or indirectly the anchorage.

History of Molar Distalization in Orthodontics

5. Expansion is also possible all the same time as the distalization of the molar, and is achieved by changing the angulations of the tubes in relation to the sagittal plane. 6. Repair is easy. Disadvantage It is a delicate appliance. The two wires must hold the movable part without binding.

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CETLIN APPLIANCE The appliance involves a combination of an extra-oral force in the form of headgear and an infra oral force in the form of a removable appliance. In molar distalization, bodily distal movement rather than distal tipping of the maxillary molars is essential. When there is only a distal tipping, the molars relapse messily, uprighting under their apices to comeback to its original position. To overcome these drawbacks, the Cetlin appliance utilizes a removable appliance intra orally to tip the crowns distally and then an extra oral force to upright the roots. So the intraoral removable appliance can be called the crown mover while the extra-oral force, is the root mover.

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supplies only 30 g of force on the molars. The springs are placed as far gingivally as possible to minimize crown tipping and to cause molar movement without Irritation. • The removable appliance exerts a force, which moves the molar crowns distally, with relative ease. • The extra oral headgear on the other hand exerts a force of 150 g per tooth and is used to control root position. The headgear is advised to be worn for 12–14 hours/day. • When using a cervical headgear, it is generally necessary to elevate the outer bow to produce an appropriate “force couple” that will move the roots distally, by directing the line of force above the outer of mass of the molar. THE LOKAR APPLIANCE The Lokar appliance was developed by Dr Loter In 1894. Components of Lokar Appliance The appliance consists of two basic components, and they are: • A mesial sliding component • A component which inserts Into arch wire tube of the molar.

ANCHORAGE NEED

Design of the Lokar Appliance

The anchorage for the removable appliance is by proper adaptation to the palate, an acrylic shield around the four maxillary incisors and a modified Adam’s Clasp on the first premolars.

• The distalizer is inserted into arch wire tube of the first molar and the application is adapted such that it is parallel to the plane of occlusion and as close to the teeth as possible tor patient comfort. • A 0012" S.S. ligature wire hand twisted around the premolar bracket before the Lokar is fixed to the molar tube. This ligature wire is engaged around the mesial sliding component of the distalizer and tightened to activate the appliance.

EXTRAORAL FORCE • The extraoral appliance is a headgear, which is inserted into the molar tube. The headgear used in generally a cervical or a high pull type, depending on the usual consideration of skeletal pattern. • The removable appliance is worn 24 hours a day. The appliance also contains a bite plane to disengage the molars (to aid in rapid molar movements).

Force Applied and Activation of the Appliance The force is delivered by NiTi Coil spring, which gets compressed during activation.

THE FORCE APPLIED • In the removable appliance, the spring is activated only 1 to 1.5 mm, measured along the occlusal surface of the molar and It

Anchorage The anchorage is by a Nance appliance, soldered to the premolars.

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Activation A 0.012" S.S. ligature wire is hand twisted twice around the premolar bracket, such that the free ends of the ligature face distally. One of the free ends is then passed over the mesial sliding component of the mainframe and tightened to activate the appliance. The force is delivered by the NiTi Coil spring, which gets compressed during activation. The best activation is achieved by compressing the spring by 2–3 mm. Re-activation of the Appliance Re-activation is done at 5–6 weeks interval.

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K-LOOP MOLAR DISTALIZER The K-loop molar distalizer was developed by Vamn Kalra. The K-loop molar distalizer consists of: • A K-loop—to provide the forces and moments • A Nance button—to resist anchorage. – The K-loop is made of 0.017- x 0.025" TMA wire. Which can be activated twice as much as stainless steel before it undergoes permanent deformation. A loop made of ‘TMA’ also produces less than half the force of one made with stainless steel. – Each loop of the ‘K’ should be 8 mm long and 1.5 mm wide. The legs of the ‘K’ are bent down 20° and inserted into the molar tube and the premolar bracket. The wire is marked at the mesial of the molar tube and the mesial of the premolar bracket. Stops are bent into the wire ‘1 mm’ distal to the distal mark and ‘1 mm’ mesial to the mesial mark. Each stop should be well-defined and about 1.5 mm long. These bends help keep the appliance away from the mucobuccal fold, allowing a 2 mm activation of the K-loop. – The 120° bends in the appliance legs produce moments that counteract the tipping moments created by the force of the appliance, and these moments are reinforced by the moment of activation as the loop is squeezed into place. Thus, the molar undergoes a translatory movement instead of tipping. Root movement continues even after the force has dissipated. If an extrusive or intrusive force against the molar is not desired, it is

important to center the K-loop between the first molar and the pre molar. – For additional molar movement, the appliance is reactivated 2 mm after 6-S weeks. The loop is easy to remove from the molar tube, since the distal end of the wire is not bent. In most cases, one reactivation, producing a total of as much as 4 m of distal molar movement is sufficient. – The palatal Nance button, held in place by wires extending from bands on the first premolars or first deciduous molars, is primarily responsible for preventing anterior movement of the first premolars. The button should be large enough to, provide adequate anchorage and prevent tissue impingement, but should be kept away from the teeth. The acrylic should not be built up so that the button acts as a bite plane. – The premolars moved forward by about ‘1 mm’ during ‘4 mm’ of molar distalization. If necessary, the anchorage can be reinforced by attaching a straight pull or high-pull headgear with a force of 150 g to the premolars. Advantages The K-loop molar distalizing appliance has the following advantages: • Simple yet efficient • Controls the moment-to-force ratio to produce bodily movement, controlled tipping or uncontrolled tipping as desired • Easy to fabricate and place • Hygienic and comfortable for the patient • Requires minimal patient co-operation lowcost. THE DISTAL JET APPLIANCE The distal jet was designed by Akto Carano and Miiuro Testa in 1996. Appliance Design • The appliance consists of bilateral tubes of 0.036" internal diameter which are attached to an acrylic name button. NiTi Coil spring and screw clamps are slide over each tube. • The wire extending from the acrylic, through each tube ends in a bayonet bend that is inserted into the lingual sheath of the first

History of Molar Distalization in Orthodontics

molar band. An anchor wire from the Nance button is soldered to the bands on the 2nd premolars.

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Components 1. The transpalatal connectors—rigidly immobilize the premolars and provide a support to the Nance button. 2. The Bayonet director unit: Lumen of the tube portion supports the molar bayonet, while its outside diameter supports the spring and the activation lock. 3. The molar bayonet: It is drawn out of the bayonet director unit during distalization and inserted into the lingual sheath. The distal step prevents the spring from riding on the vertical arm of the molar bayonet while activating the appliance. 4. NiTi springs: NiTi coil springs of 150 gm are used for children and 250 gm used for adults. 5. Stainless steel springs: The appliance can also be fabricated with stainless steel springs. 6. Activation locks—to compress and activate the springs. 7. Lock wrench: To engage and tighten (the screw of the activation lock). Activation • The distal jet is activated by sliding the damp closer to the first molar once a month. • Once the distalization is complete, the appliance can be converted to a Nance retainer simply by replacing the clamp-spring assemblies with light-cured or cold cure acrylic and cutting off the arms or the promoters. Advantages The advantages of the distal-jet appliance are listed below: • Minimal patent discomfort • Minimal or no molar tipping • Ease of fabrication • Ease of insertion • Esthetically acceptable • Well-tolerated by patients • Ease of conversion to a Nance holding arch to maintain the distalized molar position • It can be used with a full-fixed appliance There are several modifications to the distaljet appliance, for different purposes. They are:

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1. Conversion to Nance holding arch. 2. Double set screw distal Jet appliance. 3. Incorporation of helical loops into bayonet wire far molar rotation and up-fighting. 4. Incorporation of Jack screws for maxillary expansion. THE CROZAT APPLIANCE The crozat appliance is similar to the crickett appliance but has palatal and lingual bars instead of stainless steel wire components. Dr Crozat viewed the appliance as acting in a truncated cone or funnel. As the molars are being translated distally in a divergent direction, expansion must be placed in the appliance to avoid the more roots striking the lingual cortical plate, blocking movement. Over-expansion can also impede distal movement by emerging the roots against the buccal plate. Treatment of a bilateral class II malocclusion with a good lower arch is begun with rotation adjustments of the upper molars. First the measurement is made between the lingual arms; and each crib clasp complex is rotated to increase this measurement ½ mm per side. Once the rotation adjustment is begun every third rotation adjustment, the molars are expanded to keep the teeth tracking back into a more divergent portion of the arch. Once the molars are derotatad, class II elastics are added to continue distal movement. Similar unilateral class II can also treated, with crozat appliance. Dr Crozat introduced this appliance in 1919. Dr Crozat’s goal was to solve crowding by the distal movement of molars. As he moved molars distally, expansion of the appliance was necessary because the bony dental arch itself is wider in the posterior regions. MOLAR DISTALIZATION BY MAGNETS • Magnets have been used intra-orally for a variety of reasons. More often for retention of prosthesis. In contemporary orthodontics, light continuous force (75 to 100 g) are commonly used to correct malocclusion with typical tooth movement of 0.5 mm/week. • Miniature Samarium-cobalt (Sm-Co) magnets are used and they have been proved to be effective and efficient force delivery systems. Ferrite, Ainico or platinum cobalt have been

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• •

•

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History of Orthodontics

tried but left out due to their very low magnetic strength and hence larger size. The magnets can either be used in the attractive or the repelling state. The repelling state is preferred. It was found that the Sm-Co magnet; when used, exert very high forces of more than 200 omi at small separations, while optimum orthodontic forces were generated (75 to 180 g), when separation was 0.5 to 1.00 mm. Magnetic Force = (Separation)n = (d)n The force exerted by the magnets decrease from 200 gms at contact to about 409 gms at 2mm, with a rapid decrease of force at greater separations. The magnets used showed good biocompatibility when they were coated. The stainless steel coated samarium-cobalt magnets can be recycled and showed good biocompatibility.

THE MAGNETS • The magnets are four in number and they are encased in a steel sleeve with a finely machined hole in the center and coated with a biocompatible polymer to avoid leaching out of products. • Two of the magnets are pre-set in regulation (on each wire) for easy insertion bilaterally. Both repelling magnets on each wire are clamped together to avoid possible loss of magnet. THE KLAPPER SUPERSPRING This appliance is an auxiliary which is fitted to fully banded upper and lower fixed appliances (ORTHO design, 744 Falls Circle, Lake Forest, Illinois 60045, USA). Design of the Appliance The appliance consists bilaterally of a length multi-flex nickel-titanium which is bent back on it attaching to the upper first molar tube and attaching to the lower arch wire by means of a helical loop. The springs lie in the buccal vestibule. The effect of the spring is to place a distalizing and intrusive force to the upper first molar. Latest Design of Klapper Super Spring The latest design of the spring requires a special oval tube to be fitted to the upper first molars. This

facilitates buccolingual adjustment of the springs in the vestibule and aids patient comfort. The springs can be readily removed for adjustment or activation. There have been no studies to date documenting results achieved with this appliance. Availability of the Appliance The appliance comes in two sizes: • 27 mm primarily designed for extraction cases and • 40 mm for non-extraction cases. • The springs are paired for left and right sides. Indications 1. Dental Class II malocclusion. 2. Deep bite with retroclined mandibular incisors. Contraindications 1. Cases predisposed to root resorption. 2. Dental and skeletal open bites. 3. Vertical growth with high mandibular plane angle and excess lower facial height. HERBST APPLIANCE The Herbst bite jumping mechanism was developed by Emil Herbst in the early 1900’s.The original banded design of this appliance was introduced at the international dental congress in Berlin (Germany) by Herbst in 1905. It was introduced by Pancherz. Pancherz used a banded Herbst design that involved the: • Placement of bands on molar and premolar Maxilla • Bands are connected by copper lingual wire • Bands on lower right first premolar and lower right first premolar Mandible • Bands are connected by a lower lingual arch wire Herbst Appliance The Herbst appliance is a fixed functional orthopedic appliance having passive tube and plunger system with the exact length of the tube determining the amount of anterior mandibular development. The tube is attached to a maxillary posterior root, whereas the plunger is fixed anteriorly to the mandibular dentition and slides through the tube during opening and closing movements.

History of Molar Distalization in Orthodontics

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THE MANDIBULAR ANTERIOR REPOSITIONING APPLIANCE (MARA) The Mandibular Anterior Repositioning Appliance (MARA, Allesee Orthodontics Appliances, PO Box 725, Sturtevant, WI 53177, USA) MARA consists of cams made from 0.060 square wire attached to tubes (0.062 square) on upper first molar bands or stainless steel crowns. A lower first molar crown has a 0.059 arm projecting perpendicular to its buccal surface, which engages the cam of the upper molar. The appliance is adjusted so that when the patient closes, the cam on the upper first molars guides the lower first molars and repositions the mandible forwards into a Class I relationship. There have been no studies to date documenting results achieved with this appliance. The developers of the appliance recommend a 12month treatment time to achieve a bite jumping or orthopaedic effect. Stabilization of the lower molars is assisted by the fitting of a lingual arch and on the upper arch a transpalatal bar to stabilize the upper molars is placed. This appliance does not require the placement of attachments on teeth other than the first molars. Indication Skeletal Class II with mandibular deficiency. Contraindications 1. Dolichofacial growth pattern. 2. Cases predisposed to root resorption. 3. Dental and skeletal open bites. 4. Vertical growth with high mandibular plane angle and excess lower facial height. SAIF SPRINGS Design of the Appliance These are long nickel-titanium closed coil springs that are used to apply Class II inter-maxillary traction when fully banded fixed appliances are in place (Saif Springs, Pacific Coast Manufacturing Inc, 18506 142nd Ave, NE Woodinville, WA 98072, USA). The springs are tied in place with steel ligatures and are worn in place of inter-maxillary elastics. Availability of the Saif Spring The springs are available in two lengths:

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• 7 and • 10 mm. Pre-requisites of the Spring No longitudinal research studies on this auxiliary are available in the literature to date. Starnes (1998) recommends that for successful treatment to be carried out the prerequisites are as follows: • Prior correction of deep bites; • Stabilization of each arch with a large rectangular arch wire; • Direction of force as horizontal as possible; • Sufficient resistant torque (lower incisor lingual crown torque); • Perfect fit of bands; • Proper placement of hooks for spring attachments. THE ‘FASTBACK’ APPLIANCE FOR MOLAR DISTALIZATION Modern Orthodontic Science is constantly exploring new non-extraction therapies through research carried out employing appliances that will allow the Orthodontist to gain space both transversally and distally. Consequentially, in recent times we have observed an increase in the number of appliances for the distalization of the upper molars. Italians have been particularly prolific in this area, probably on account of many of our young patients being reluctant to follow the therapeutic indications that come with extraoral tractions. The common goal for all those involved in developing new distalizing appliances appears to be the ability to provide a dental movement that is bio-mechanically controlled and generated by adequate forces, while keeping undesired contramovements to a minimum., the ideal Distalizer should occupy the smallest possible space, interfere as little as possible with function and provide bodily distal movement of the dental elements involved with minimal (or absence of) patient compliance. Distal movement should occur in the patient with minimal damage to the surrounding tissues and function, generating minimal (or absence of) contra-movements. The appliance used should be engineered in such a way that would make therapy management easy and safe. The ‘Fastback’ Molar Distalizer is now fully established as a ‘reference’ appliance in the

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Orthodontic field. A growing number of Professionals, having had the opportunity to fully evaluate and appreciate the ease and safety of use as well as the bio-mechanical development provided by this device, are now prescribing it regularly whenever they need to gain space in the posterior region. At the time of writing, 6 years have passed since the initial prototypes of ‘Fastback’ devices were introduced.

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FEATURES OF FAST BACK APPLIANCE Fast back features are as follows: • Easy to plan and assemble • Reduced bulk • Minimal patient discomfort • Good aesthetics • Continuous, constant forces are at work at all times • Intensity and direction of the forces applied can be • Accurately controlled

• Reduced or minimal loss of anchorage • Reduced or minimal contra-movements • Bodily Distalization occurs, no risk of undesired movements • Easy, non-frequent Activation • Checks every 4/6 weeks, cost-effective patient • management • Spherical or long ends ensure the appliance stops • when not activated, should the patient skip one or more appointments • The ‘Fastback’ can be used in conjunction with fixed • Buccal appliances (brackets). There are three versions of the ‘Fastback’ appliance: • FB1 (Monolateral FB with ‘Tripod’ Anchorage unit) with or without ‘Nance’ button • FB2 (Bilateral FB ) with ‘Nance’ button • FB3 (Bilateral FB ) with ‘Nance’ button and Extensions, or Rests, to the Canines.

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Suggested Reading

1. A practical guide to the management of the teeth. 1819:198. 2. Ackerman JL, Profitt WR. The characteristics of malocclusion: A modern approach to classification and diagnosis. Am J Orthod 1969;56:443-54. 3. Adams CP. The modified arrowhead clasps. Dent Record, 1950; 70:I43. 4. Adams. Removable appliances yesterday and today. Am J Orthod, 1969;202-18 5. Ahmad KA, Drummond JL, Graber TM, BeGole E. Magnetic strength and corrosion of rare earth magnets. Am J Orthod Dentofacial Orthop 2006;130:275 e11-15. 6. Ainsworth GC. Some thoughts regarding methods and a new appliance for moving dislocated teeth into position. Int Dent J, 1904; 24:481. 7. Alexander D. Vardimon AD, Graber TM, Drescher D, Bourauel C. Rare earth magnets and impaction. Am J Orthod Dentofac Orthop. 1991; 100: 494-512. 8. Allan G Brodie. Orthodontic concepts prior to the death of Edward H Angle. AO, 1956; Vol. 26, Page 144-54. 9. Andressen V. The Norwegian system of functional gnathoorthopedics. Acta Gnathol 1936;1:4. 10. Andrews lF. The keys for normal occlusion . AJO, 1972; Vol.62, Page 296. 11. Angel EC. Treatment of irregularities of the permanent teeth. Dent Cosmos 1860;1:540. Dent Cosmos, 1860; 1:281. 12. Angle CP. The modified arrowhead clasp—some further considerations. Dent Record, 1953; 73, 332-3. 13. Angle EH. Evolution of orthodontia—recent developments. Dent Cosmos. Reprint August, 1912:5.

14. Asbell MB. Bicentenary of a dental classic: John Hunter’s “Natural History of the Human Teeth.” J Am Dent Assoc, 1972;84:1311-4. 15. Asbell MB. The American Association of Orthodontists: a history, 1965-90 [unpublished manuscript]. p. 68-71. 16. Atkinson SA. Albin Oppenheim. Am J Orthod, 1957; 43:46-51. 17. Badcock JH. The screw expansion plate. Trans. Brit Soc Orthop, pp 1911;3-8. 18. Barrer, HG. Treatment timimg of borderline cases. J Clin Orthodont, 1971;5:191-9. 19. Bates v. State Bar of Arizona, 433 U S 350, 364, 1977. 20. Baty DL, Storie DJ, von Fraunhofer JA. Synthetic elastomeric chains: a literature review Am J Orthop Dentofac Orthop, 1994;105:536-42 21. Baumrind S, Korn EL, Boyd RL, Maxwell R. The decision to extract: part 1. Am J Orthod Dentofacial Orthop, 1996;109:297-309. 22. Begg PR, KeslingPC. Begg orthodontic theory and technique (3 Edn). (W.B. Saunders). 23. Begg PR. Begg orthodontic theory and technique. Philadelphia; WB Saunders: 1965. 24. Bernhard Schwaninger. Evaluation of the straight arch wire concept. AJO, 1978; Vol. 74,188-96. 25. Bishara SE, Staley RN. Mixed-dentition mandibular arch length analysis. Angle Orthod 1984;36:130-5. 26. Björk A. The face in profile, an anthropological X-ray investigation on Swedish children and conscripts. Svensk Tandl Tidskr 1947;40 Suppl. 27. Bogue EA. Orthodontia of the deciduous teeth. Dent Digest 1912;13:671-7;1913;19:9-14; 1919; 25:193-210. 28. Bolton WA. Disharmony in tooth size and its relation to the analysis and treatment of malocclusion. Angle Orthod 1958; 28: 113-30.

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29. Bonham ManessW. The straight wire concept. AJO, 1978; Vol.73, 541-50. 30. Breece GL, Nieberg LG. Motivations for adult orthodontic treatment. J Clin Orthod, 1986; 20(3):166-71. 31. Brodie AG. On the growth pattern of the human head from the third month to the eighth year of life. Am J Anat, 1941;68:209-62. 32. Buonocore MG. A simplified method of increasing the adhesion of acrylic filling materials to enamel surfaces. Journal of Dental Research. 1955;63/S.I Abstract No. 556, p232 33. Cacciafesta V, Sfondrini MF, Ricciardi A, Scribante A, Klersy C, Auricchio F. Evaluation of friction and stainless steel aesthetic self-ligating brackets in various bracket-archwire combin-ations. Am J Orthod Dentofac Orthop, 2003; 124:395-402. 34. Caniklioglu MC, Ozturk Y. Guray bite raiser: its clinical use in lingual orthodontic treatment. J Lingual Orthod, 2002; 2(3):71-7. 35. Carey CW. Linear arch dimensions and tooth size. AJO, 1949;35:764-6. 36. Carey CW. Linear arch dimensions and tooth size. AJO, 35:764-6,194. 37. Carey CW. Lower arch dimension and tooth size. Am J Orthod, 1949;35:762-75. 38. Carroll-Ann Trotman, James A. McNamara Jr. Association of lip posture and the dimensions of the tonsils and sagittal airway with facial dimensions. AO 1997;67:425-32. 39. Carter RN. Clinical management of ceramic brackets. J Clin Orthod, 1989;23(12):807–9. 40. Castro FM. The trend of orthodontic treatment. Proceedings of the American Society of Orthodontists, 1930 and 1932;119-23. 41. Castro FW. A historical sketch of orthodontia. Dent Cosmos, 1934;66:112. 42. Cetlin NM, Ten Hoeve AJ. Nonextraction treatment. J Clin Orthod, 1983;17:396-413. 43. Charles H Tweed. Clinical orthodontics, 1st Edn, Vol.1 (The C.V. Mosby Company). 44. Columbia. Sentinel, June 4, 1796. 45. Coreil MN. Uncompromising aesthetic treatment—dispelling the myths about ceramic brackets. Clinical Impressions, 2004;13(1):4-11. 46. Cozza P, Baccetti T, Franchi L, McNamara JA Jr. Treatment effects of a modified quad-helix in patients with dentoskeletal open bites. AJO 2006Jun;129(6):734-9. 47. Creekmore T. Lingual orthodontics—Its renaissance. Am J Orthod Dentofacial Orthop, 1989; 96(2):120–37. 48. Curtis EK. Orthodontics at 2000. St Louis: American Association of Orthodontists; 2000. pp. 27.

49. Curtner RM. Personal communication. November 1, 1995. 50. de Almeida MR, Henriques JF, de Almeida RR, Weber U, McNamara JA Jr. Short-term treatment effects produced by the Herbst appliance in the mixed dentition. Angle Orthod. 2005 Jul;75(4): 540-7. 51. De Medicina, Edition of Pincius for Fontana, Venice, 6 May 1497. Library #131881 (incunabula), College of Physicians, Philadelphia. For English translation see Foster EW. “Celcus”. Dent Cosmos, 1879;21:235-41. 52. Deguchi T, Kuroda T, Hunt NP, Graber TM. Long-term application of chin-cup force alters the morphology of the dolichofacial Class III mandible. Am J Orthod Dentofacial Orthop 1999;116:610-5. 53. Deguchi T, Kuroda T, Minoshima Y, Graber TM. Craniofacial features of patients with Class III abnormalities: Growth-related changes and effects of short-term and long-term chin-cup therapy. Am J Orthod Dentofacial Orthop 2002;121:84-92 54. Deguchi T, Takano-Yamamoto T, Kanomi R, Hartsfield JK Jr, Roberts WE, Garetto LP. The use of small titanium screws for orthodontic anchorage. J Dent Res, 2003;82:377-81. 55. Dent Cosmos 1887;29:275. 56. Dental Register, 1891;45:369. 57. Dewel BF. A question of terminology. Am J Orthodont, 1970;58:78-9. 58. Dewel BF. Orthodontics: midcentury recollections. Eur J Orthod, 1981;3:77-8. 59. Dewel BF. Prerequisites in serial extraction. Am. J Orthodont, 1969; 55:633-9. 60. Dewel BF. Second premolar extraction in orthodontics: principles, procedures, and case analysis. Am J Orthod, 1955;441:107-20. 61. Dewel BF. Serial extraction—its limitationssand contraindications. Arizona Dent J, Sept 15, 1968; 14:14-30. 62. Dewel BF. The Case-Dewey-Cryer extraction debate: a commentary. Am J Orthod, 1964; 50:862-5. 63. Dewel, BF. Precautions in serial extraction. Am J Orthodont, 1971;60:615-8. 64. DJ Bowells. The straight wire appliance : Dental up date, 1986; Vol.13, 367-76. 65. Dougherty HL, Allergy to rubber, Am J Orthop Dentofac Orthop, 1993;104:23A-24A. 66. Downs, William B, 1899-1966 (Obituary), Angle Orthod, 1983;53:1. 67. Dwinnell WH. Priority in the use of steel jackscrews. Dent Cosmos, 1886;28;171-2. 68. Earl W Renfroe. Edgewise (Lea and Febiger 1975).

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69. Einleitung zur Nötigen Wissenschaft eines Zahnarztes, (Introduction to the important science of dentistry), Wien, 1766:182. 70. Eitzen C. Implant anchorage in orthodontics. In: Technology spotlight. Available at: http:// www.dentalcompare.com/spotlight.asp? spotlighted_8. Accessed December 25, 2006. 71. El-Bialy T, El-Shamy I, Graber TM. Repair of orthodontically induced root resorption by ultrasound in humans. Am J Orthod Dentofacial Orthop 2004;126:186-93. 72. El-Bialy T, El-Shamy I, Graber TM. Growth modification of the rabbit mandible using therapeutic ultrasound: is it possible to enhance functional appliance results? Angle Orthod. 2003; 73:631–639. 73. Evans TW. Dental Newsletter, 1854;8:30. 74. Eveleth PB, Tanner JM. World wide variation in human growth (2nd edn), Cambridge, Mass. Cambridge University Press, 1990. 75. Everelt Shapiro. Broukline Mass. Current concepts and clinical applications of the edgewise arch mechanics, AJO, 1957; Vol.43, 174-91. 76. Faltin KJ, Faltin RM, Baccetti T, Franchi L, Ghiozzi B, McNamara JA Jr. Long-term effectiveness and treatment timing for Bionator therapy. Angle Orthod. 2003 Jun;73(3):221-30. 77. Fauchard P. The surgeon dentist or treatise on the teeth. (Translated from second edition of 1746 by Lilian Lindsay) London: Butterworth and Co, 1946:130. 78. Federal Gazette, Philadelphia, June 14, 1797. 79. Ferris T, Alexander RG, Boley J, Buschang PH. Long-term stability of combined rapid palatal expansion-lip bumper therapy followed by full fixed appliances. Am J Orthod Dentofacial Orthop, 2005;128:310-25. 80. Fillion D. The resurgence of lingual orthodontics. Clinical Impressions, 1998; 7(1):2-9. 81. Fletcher GGT. The Begg appliance and technique (wright). 82. Fogel MS. Borderline malocclusions, differential diagnosis. Part one, J Clin Orthodont, 1971;5;24859. Part two. 1971;5:305-20. 83. Foster TD. A Textbook of Orthodontics, St Louis, Blackwell Scientific Publications, 1982. 84. Fujita K. Multilingual bracket and mushroom arch wire technique. A clinical report. Am J Orthod 1982; 82(2):120-40. 85. Fujita K. New orthodontic treatment with lingual bracket and mushroom archwire appliance. Am J Orthod, 1979;76(6):657-75. 86. Fulmer DT, Kuftinec MM. Cephalometric appraisal of patients treated with fixed lingual orthodontic appliances: historic review and

87. 88.

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253 analysis of cases. Am J Orthod Dentofacial Orthop, 1989;95(6):514-20. Furstman LL. Interview. December 6, 1987. Geran RG, McNamara JA Jr, Baccetti T, Franchi L, Shapiro LM. A prospective long-term study on the effects of rapid maxillary expansion in the early mixed dentition. AO 2006 May;129(5):63140. Glasgold AI, Silver FH, Applications of biomaterials in facial plastic surgery. CRC Press, 1991, Boca Raton, FL. Goldstein A. The clinical testing of orthodontic results. Am J Orthod 1965;51:723-55. Goren S, Zoizner R, Geron S, Romano R. Lingual orthodontics versus buccal orthodontics: biomech-anical and clinical aspects. J Lingual Orthod, 2003; 3(1):1-7. Gorman JC, Smith RJ. Comparison of treatment effects with labial and lingual fixed appliances. Am J Orthod Dentofacial Orthop, 1991; 99(3):2029. Gorman JC. Treatment of adults with lingual orthodontic appliances. Dent Clin North Am, 1988;32(3):589-620. Gottlieb, EL. Orthodontics in the year 2000. J Clin Orthod, 2000;34:9-10. Graber TM, B Neumann. Removable orthodontic appliance. WB Saunders Co. Philadelphia, 1977. Graber TM, Bzoch KR, Aoba T. A functional study of the palatal and pharyngeal structures. Angle Orthod. 1959; 29(1): 30-40. Graber TM, Chung DDB, Aoba JT. Dentofacial orthopedics vs orthodontics. J Am Dent Assoc. 1967; 75: 1145-66. Graber TM, Neumann B. Removable Orthodontic Appliances. Philadelphia. WB Saunders, 1984. Graber TM, Neumann B: Removable orthodontic Appliances. WB Saunders, Philadelphia, 1984. Graber TM, Vanarsdall RL, et al. Orthodontics, Current Principles and Techniques. Diagnosis and Treatment Planning in Orthodontics. Mosby, 2000. Graber TM. A cephalometric analysis of the developmental pattern and facial morphology in cleft palate. Angle Orthod. 1949; 19(2): 91-100. Graber TM. An orthodontic perspective after 75 years. Am J Orthod. 1976; 69(5): 572-83. Graber TM. Auxiliary personnel – pillars of practice procedure. Am J Orthod. 1965; 51(6): 41236. Graber TM. Books for the dentist. J Am Dent Assoc. 1974; 88: 1322-42. Graber TM. Ch. 4 - Current status of magnetic forces in orthodontics (Biomechanics in clinical orthodontics) W.B. Saunders Co. 1997.

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106. Graber TM. Extraoral force – facts and fallacies. Am J Orthod. 1955; 41: 490-505. 107. Graber TM. Maxillary second molar extraction in Class II malocclusion. Am J Orthod. 1969; 56(4): 331-53. 108. Graber TM. Normal occlusion. Dent Clin North Am. 1968; Jul.: 273-90. 109. Graber TM. Notes and comments. Dental Abstracts 1976; 21(12): 712-13. 110. Graber TM. Occlusal splints (Letter to Editor). J Am Dent Assoc. 1980; 100: 171a. 111. Graber TM. On thumbsucking (Letter to Editor). J Am Dent Assoc. 1970; 81: 805. 112. Graber TM. Orthodontics: Principles and Practice. WB Saunders, 1998. 113. Graber TM. Postmortems in post-treatment adjustment. Am J Orthod. 1966; 52(5): 331-52. 114. Graber TM. Pride in orthodontics. Am J Orthod Dentofac Orthop. 2000 May;117(5):618-20. 115. Graber TM. Serial extraction: A continuous diagnostic and decisional process. Am J Orthod. 1971; 60(6): 541-75. 116. Graber TM. The “three M’s”: Muscles, malformation and malocclusion. Am J Orthod. 1963; 49(6): 418-50. 117. Graber TM. The role of upper second molar extraction in orthodontic treatment.Am J Orthod. 1955; 41: 354-361. 118. Guerini V. A history of dentistry from the most ancient times until the end of the eighteenth century. Philadelphia: Lea and Febiger, 1909. 119. Gunnell JS. A remedy for the protrusion of the lower jaw. Am J Dent Soc, 1841;2:65. 120. Hall RR, Hill DW, Beach AD. A carbon dioxide surgical laser Ann R coll Surg Engl 19771;48;1818. 121. Harradine N. Current products and practices. Self-ligating brackets: Where are we now?. Journal of Orthodontics. 2003; 30, pp262-73. 122. Hawley CA. Determination of normal arch and its application to orthodontia. Dent Cosmos, 1905;47;541-52. 123. Hellman M. An introduction to growth of the human face from infancy to adulthood. Int J Orthod, 1932;18:777-98. 124. Hellman M. The face in its developmental career. Dent Cosmos, 1935;75:685-9. 125. Hicks MJ, Flaitz CM, Westernman GH, Blakenau RJ, Powell GL, Berg JH. Enamel caries initiation and progression following low energy. Argon Laser J Clin Dent 1995;20(1):9-13. 126. Hitchcock HP. Pitfalls of the Crozat appliance. Am J Orthod, 1972;62:461-8. 127. Hixon EH, Oldfather RE. Estimation of the sizes of unerupted cuspid and bicuspid teeth. Angle Orthod, 1958;48:236-40.

128. Hong RK, Soh BC. Customized indirect bonding method for lingual orthodontics. J Clin Orthod, 1996;30(11):650-2. 129. Hong RK. Tandem archwire technique in the Fujita lingual bracket treatment. J Lingual Orthod, 2002;2(4):100-4. 130. Hower AE. A polygon portrayl of coronal and basal arch dimensions in the horizontal plane. Am J orthod, 1954; 40:811. 131. Hower AE: A polygon portrayl of coronal and basal arch dimensions in the horizontal plane. Am J orthod. 1954 ; 40:811. 132. Int J Orthod, 1924;10:471. 133. Items Interest, 1899;41:151. 134. Items Interest, 1899;41:178. 135. Items Interest, 1900;42:43. 136. Jackson VH. Some methods in regulating. Dent Cosmos, 1886;28:372-5. 137. James A McNamara Jr, Carlson DS. Quantitative analysis of TMJ adaptations to protrusive function. AJO 1979:76,6593-610. 138. James A McNamara Jr. Neuromuscular and skeletal adaptations to altered function in the orofacial region. AJO 1973;64;6;578-605. 139. James A McNamara Jr. Orthodontic treatment and temporomandibular disorders. OOO 1997:83:107-17. 140. James A McNamara. Influence of respiratory pattern on craniofacial growth. AO 1981;51:269300. 141. James A McNamara. Maxillary transverse deficiency. AJO may 2000:117:5-568-70. 142. James A. McNamara Jr, Raymond P. Howe, Terry G. Dischinger A comparison of the Herbst and Fränkel appliances in the treatment of Class II malocclusion. AJO 1990;98:134-44. 143. JC Bennet, PR Mclaughlin: Orthodontic treatment mechanics and the preadjusted appliance. 1st edn. (Wolfe). 144. Johnson JE. The twin-wire appliance. Am J Orthod Oral Surg, 1938;24:303. 145. Jost-Brinkman PG, Stien H, et al. Histological investiga-tion of the human pulp after thermodebonding of metal and ceramic brackets. Am J Orthod 1992;102:410. 146. Joyce Y. Chang James A. McNamara Jr. Thomas A. Herberger A longitudinal study of skeletal side effects induced by rapid maxillary expansion. AJO 1997:112:330-37. 147. K Calman, Hospital doctors: training for the future, London, HMSO, 1993; Dentists Register, London, General Dental Council, 1999. 148. Kesling HD. Coordinating the predetermined pattern and tooth positioner with conventional treatments. Am J Orthod Oral Surg, 1946; 32:28593.

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149. Ketcham A. Treatment by orthodontists supplementing that by the rhinologist. Dent Cosmos, 1914;54:1312-21. 150. KG. Issacson; J.K. Williams: An introduction to fixed appliances: III Edn, Page 1 (Wright). 151. Kim JH, Viana MAG, Graber TM, Omerza FF, BeGole EA. The effectiveness of protraction face mask therapy: A meta-analysis. Am J Orthod Dentofac Orthop 1999;115:675-85. 152. Kim MR, Graber TM, Viana MA. Orthodontics and temporomandibular disorder: A metaanalysis. Am J Orthod Dentofacial Orthop 2002;121:438–46. 153. Kingsley NW. A treatise on oral deformities, 1880. Republished in classics in dentistry library, Birmingham, Alabama, 1980. 154. Kingsley NW. Dent Cosmos, 1934;66:131. 155. Kingsley NW. Jumping the bite. Dent Cosmos, 1892;33:788. 156. Kjellgren, B. Serial extraction as a corrective procedure in dental orthopedic therapy. Acta Odont. Scandinav, 8:17-43, 1948; abst, Am J Orthoddont, 1949;35:471-6. 157. Kristine S. West and James A. McNamara, Jr. Changes in the craniofacial complex from adolescence to midadulthood: A cephalometric study. AJO 1999;115:521-32. 158. Krogman WM. Child Growth, Ann Arbor, Mich. The University of Michigan Press, 1972. 159. Krogman WM. Forty-years of growth, research and orthodontics. Am J Orthod, 1973; 63:357-65. 160. Kurz C, Romano R. Lingual orthodontics: historical perspective. In: Romano R, editor. Lingual orthodontics. Hamilton (ON): BC Decker; 1998; pp3-20. 161. Kurz C, Swartz ML, Andreiko C. Lingual orthodontics: a status report. Part 2: Research and development. J Clin Orthod, 1982; 16(11):73540. 162. Kusy R. Orthodontic biomaterials: From the Past to the present. Angle Orthodontist, 2002, 72:6, p501-12. 163. Lew KK. Initial alignment with .008" pulse straightened supreme Wilcock wire in lingual orthodontics. Aust Orthod J, 1991;12(1):53-4. 164. Li ZZ, Code JE, Van De Merwe WP. Er: YAG laser ablation of enamel and dentin of human teeth. Determination of ablation rates at various influences and pulse repetition rates.Laser surg Med 1992;12:625-30. 165. Linda Ratner Toth, James A. McNamara Jr. Treatment effects produced by the Twin-block appliance and the FR-2 appliance of Fränkel compared with an untreated Class II sample. AJO 1999;116:597-609. 166. Lischer BE. Time to tell. New York: Vantage; 1950.

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167. Lischer BE. What are the requirements of orthodontic diagnosis? Int J Orthod, 1933;19:37785. 168. Logan LR. Second premolar extraction in Class I and Class II. Am J Orthod, 1973;63:115-47. 169. Lundstrom A. Malocclusion of the teeth regarded as a problem in connection with the apical base. Svensk Tandl-Tidskr Supp, 1923. Reprinted in Int J Orthod, 11:591, 724, 793, 933, 1022, 1109, 1925. 170. Martinek Edward E. A comparison of various survey’s on the adequacy of basal bone. AJO,1956;42:244-254. 171. Martinek, Edward E. A comparison of various survey’s on the adequacy of basal bone. AJO, 1956;42:244-254. 172. Mayne WR. Serial extraction in orthodontics at the crossroads. D Clin North America, July 1968. 173. Mc Namara JA Jr, Brudon WL. Orthodontics and dentofacial orthopedics. Needham Press. 2nd edition. 2002. 174. Mc Namara JA Jr. A method of cephalometric evaluation. Am J Orthod. 1984; 86: 449-469. 175. McCoy JD. Applied orthodontics. 6th ed. Philadelphia: Lea and Febiger, 1946. 176. McNamara JA. A method of cephalometric evaluation. Am J Orthod, 1984;86:449. 177. Mershon JV. The removable lingual arch as an appliance for the treatment of malocclusion of the teeth. Int J Orthod, 1918;41:478;1920;12:1002; Dent Cosmos, 1920;62:698. 178. Michal Meyer. Pre adjusted edgewise appliances. Theory and Practice: AJO, 1978; Vol. 73, 485-498. 179. Midda M. The use of laser in periodontology. Curr opin Dent 1992;2;104-8. 180. Mills CM, Holman RG, Graber TM. Heavy intermittent cervical traction in Class II treatment: A longitudinal cephalometric assessment. Am J Orthod. 1978; 74(4): 361-79. 181. Moorrees CFA. The dentition of the growing child, Cambridge, Harvard University Press, 1959. 182. Nakai TT. The influence of serial extraction procedures on the soft tissues: profiles in class 2, division 1 malocclusions; a cephalommetric study. Am J Orhodont, 1968; 54:154. 183. Nance HN. The removal of second premolars in orthodontic treatment. Am J Orthod, 1949; 35:685-95. 184. National Gazette, April 11, 1826. 185. National Research Council, Polymer Science and Engineering, National Academy Press, Washington DC, 1994. 186. New York Daily Advertiser, Aug. 2, 1797. 187. Newman GV. Epoxy adhesives for orthodontic attachments. American Journal of Orthodontics. 1965;51:12. p901-12.

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206. Proffit WR. Concepts of growth and develop-ment. In: Contemporary Orthodontics, (2nd edn.) St Louis: Mosby Yearbook, 1999;2462. 207. Proffit WR. Forty-year review of extraction frequencies at a university orthodontic clinic. Angle Orthod, 1994;64:407-14. 208. Profitt WR, Ackerman JL. Rating the characteristics of malocclusion: A systematic approach for planning treatment. Am J Orthod 1973;64(3):258-69. 209. Profitt Wr: Contemporary Orthodontics, st louis, CV Mosby, 1986. 210. Pullen HA. Expansion of dental arches and opening maxillary suture in relation to development of the internal and external face. Dent Cosmos, 1912;54:509-28. 211. Raymond C Thurow. Edgewise orthodontics, 4th Edn. (The CV Mosby Company) 212. Reed A Holdaway. Bracket angulation as applied to the edgewise appliance. AO. 1952;227-36. 213. Reish MS, Rubber consumption is rising, Chem. and Eng News, August 14,1995. 214. Richard A Hocevar. Why edgewise? AJO, Vol. No.80; 237-55. 215. Ricketts RM. Keystone triad. Part 2. Am J Orthod, 1964;50:728-50. 216. Ringenberg, QM. Serial extraction: stop, look, and be certain. Am J Orthodont, 1964;50:327-36. 217. Robert HW Strang, 1881-1982 (Obituary). Angle Orthod, 1983;53:1. 218. Rogers AP. Evolution, development, and application of myofunctional therapy in orthodontia. Am J Orthod Oral Surg, 1939;25:1-19. 219. Rossman JA, Cobb CM, Laser in periodontal therapy. Periodontology 2000;1995:150-64. 220. Rufenacht CR. Fundamentals of esthetics. Chicago; quintessence; 1990. 221. Rupertogonzalez-Giralda. Dental specialization in spain. BJO, Feb, 1908 . 222. Russell JS. Current products and practices. Aesthetic Orthodontic Brackets. Journal of Orthodontics. 2005; 32, pp146-63. 223. Salzmann JA. Handicapping malocclusion assessment to establish treatment priority. Am J Orthod, 1968;54:749-65. 224. Salzmann JA. Principles of orthodontics, 2nd ed. Philadelphia: JB Lippincott, 1950:721. 225. Sarver DM, yanosky M, Principles of cosmetic dentistry in orthodontics; part 3. Laser treatment for tooth eruption and soft tissue problems. Am J Orthod Dentofacial Orthop 2005; in press. 226. Schoppe RJ. An analysis of second premolar extraction procedures. Angle Orthod, 1964;34: 292-302. 227. Schwab DT. The borderline patient and tooth removal. Am J Orthodont, 1971;59:126-45.

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228. Schwarz AM, M Gratzinger. Removable Orthodontic Appliances. WB Saunders Co. Philadelphia, 1966. 229. Scuzzo G, Takemoto K. Lingual straight-wire technique. In: Scuzzo G, Takemoto K, editors. Invisible orthodontics. Berlin: Quintessence Verlag; 2003. pp145-56. 230. Shankland WM. The American Association of Orthodontists. St. Louis: CV Mosby: 1971. 231. Sheldon Peck. A Biographical Portrait of Edward Hartley Angle, the First Specialist in Orthodontics, Part 1. The Angle Orthodontist: November 2009, Vol. 79, No. 6, pp. 1021-7. 232. Sheldon Peck. A Biographical Portrait of Edward Hartley Angle, the First Specialist in Orthodontics, Part 2. The Angle Orthodontist: November 2009, Vol. 79, No. 6, pp. 1028-33. 233. Sheldon Peck. A Biographical Portrait of Edward Hartley Angle, the First Specialist in Orthodontics, Part 3. The Angle Orthodontist: November 2009, Vol. 79, No. 6, pp. 1034-6. 234. Silver FH. Biomaterials, medical devices and tissue engineering: an integrated approach. Chapman and Hall, 1993, London. 235. Simon PW. On gnathostatic diagnosis in orthodontics. Int J Orthod, 1924;10:755-77. 236. Sinclair PM, Cannito MF, Goates LJ, Solomos LF, Alexander CM. Patient responses to lingual appliances. J Clin Orthod, 1986; 20(6):396-404. 237. Smith SS, Buschang PH, Watanabe E. Interarch tooth size relationship of 3 populations. Am J Orthod Dentofacial Orthop, 2000;117:169-74. 238. Sung JH. History of skeletal anchorage and development of microimplants for orthodontic anchorage. Unpublished manuscript; via e-mail; December 26, 2005. 239. Suwannee. The effect of premolar extraction: A long-trem comparison of outcomes in “clear cut” Extraction and non-extraction class 2 patients. 240. Swinehart EW. Orthodontic bands. In: Dewey M, Anderson M, eds. Practical Orthodontia. St. Louis: CV Mosby: 1955, p. 201. Dent Cosmos 1864;5:503. 241. Tanaka MM, Johnston LE. The prediction of the size of the unerupted canines and premolars in a contemporary orthodontic Population. J Am Dent Assoc 1974;88:798 242. Tanaka MM, Johnston Le. The prediction of the size of the unerupted canines and premolars in a contemporary orthodontic Population. J Am Dent Assoc, 1974;88:798. 243. Tanner JM, Whitehouse RH, Takaishi M. Standards from birth to maturity for height, weight, height velocity and weight velocity in British children, Arch Dis Child. 1966;41:454-71.

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244. Terwilliger. The development of the edgewise arch mechanism and its place in contemporary orthodontics. A J O, 1951;Vol.37,670-8. 245. This paper is based on a larger study, G S Taylor, ‘Review of the Transactions of the British Society for the Study of Orthodontics, 1907–1971’, DDS Thesis, University of Glasgow, 2004. 246. Thomas M Graber, Brainerd F Swain. Current orthodontic concepts and technique (II Edn.) Vol.No:5, 453-74. 247. Thomas M Graber, Brainerd F Swain. Orthodontics current principles and techniques (LV Mosby company) 1st Indian edition. 248. Tiziano Baccetti, Lorenzo Franchi, Linda Ratner Toth, James A McNamara Jr. Treatment timing for Twin-block therapy. AJO 2000;118:159-70. 249. Todd TW. Heredity and environment, facts in facial development. Int J Orthod, 1932;18:799-808. 250. Tucker EJ. Irregularities of the teeth. Dent Newsletter, 1853;6:95. 251. Tulley Wj, AC Campbell. A Manual of practical Orthodontics. J Wright and Sons, Bristol, 1960. 252. Vaden JL, Dale JG, Klontz HA. The TweedMerrifield Edgewise appliance: philosophy, diagnosis, and treatment. In: Graber TM, Vanarsdall RL, editors. Orthodontics—current principles and techniques. St Louis: Mosby Year Book Inc.; 1994. pp. 627-84. 253. Valiathan A, Siddhartha D. Fibre reinforced composite arch-wires in Orthodontics: Function meets aesthetics. Trends Biomaterials. Artif. Organs, 2006;20:1pp.16-19. 254. Vardimon AD, Graber TM, Drescher D, Bourauel C. Rare earth magnets and impaction. Am J Orthod Dentofacial Orthop 1991; 100:494-512. 255. Vardimon AD, Graber TM, Pitaru S. Repair process of external root resorption subsequent to palatal expansion treatment. Am J Orthod Dentofac Orthop 1993;103:120-30. 256. Vardimon AD, Graber TM, Stutzman J, Voss L, Petrovic AG. Reaction of the pterygomaxillary fissure and the condylar cartilage to intermaxillary Class III magnetic mechanics. Am J Orthod Dentofac Orthop 1994;105:401-13. 257. Vardimon AD, Graber TM, Voss LR, Lenke J. Determinants controlling iatrogenic external root resorption and repair during and after palatal expansion.Angle Orthod. 1991; 61(2): 113-22. 258. Vardimon AD, Graber TM, Voss LR, Muller TP. Functional orthopedic magnetic appliance (FOMA) III-Modus operandi. Am J Orthod Dentofac Orthop.1990; 97(2): 135-48. 259. Vardimon AD, Graber TM, Voss LR, Verrusio E. Magnetic versus mechanical expansion with different force thresholds and points of

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application. Am J Orthod Dentofacial Orthop 1987;92: 455-66. Vardimon AD, Graber TM, Voss LR. Stability of magnetic vs. mechanical palatal expansion. Eur. J Orthod. 1989; 11(2): 107-15. Vardimon AD, Stutzmann JJ, Graber TM, Voss LR, Petrovic AG. Functional orthopedic magnetic appliance (FOMA) II-Modus operandi. Am J Orthod Dentofac Orthop 1989;95:371-87. Von Fraunhofer JA, Allen DJ, Orbell GM. Laser etching of enamel for direct bonding. Angle Orthod 1993;63:73-6. Wachman C. Treatment of the teeth—Andressen method. Am J Orthod, 1949; 33:61 Wahl N. A short history of the Pacific Coast Society of Orthodontists. Part 1. PCSO Bull, 2000;72:30-4. Walsh LJ, Abood D, Brockhurst PJ. Bonding of resin composites to carbon dioxide laser— modified human enamel. Dent Mater 1994;10:162-6. Wayne A Bolton. The clinical evaluation of tooth size analysis. AJO. 1962;48:504-529. Wayne A Bolton. The clinical evaluation of tooth size analysis. AJO, 1962; 48:504-29.

268. Wayne Allen Bolton. Dishormony in tooth size,and its relation to the analysis and treatment of malocclusion. Angle ortho, 1958; 28:113-130. 269. Weinberger BW. [citing EJ Tucker]. Importance of regulating the teeth and employment of gum elastics. Am J Dent Soc, 1850;11:28-31. 270. Weinberger BW. Orthodontics, and historical review of its origin and evolution. St. Louis: CV Mosby; 1926. 271. Weinberger BW. The contribution of orthodontia to dentistry. Dent Cosmos, 1936;78:849. 272. Weinberger BW. The contribution of orthodontia to dentistry. Dent Cosmos, 1936;78:844-53. 273. Wiechmann D. Modulus-driven lingual orthodontics. Clinical Impressions, 2001;10(1):2-7. 274. William R Profit: Contemporary orthodontics , II Edn (Mosby) Page 357-62. 275. Wilton Marion Krogman. The creativity of Edward.H. Angle retrospect and prospect; A O 1976;Vol.46; 209-18. 276. Wylie Wendell L. 1913–1966, (Obituary), Angle Orthod, 1960;36:177. 277. Zachrisson BU. Bonding in orthodontics. In Graber Tm, Vanarsdall RL(Eds). Orthodontics: current principles and Techniques, Ed 3, st Louis, Mosby.

Index

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Page numbers followed by f refer to figure and t refer to table

A Adam’s clasp 162 with incorporated helix 163 with soldered hook 163 with traction hook 163 Adult orthodontics 19 Advantages of lasers in soft tissue surgery 52 metal brackets 107 removable appliances 161, 162 Aesthetic component 218 Aims of orthodontic treatment 15, 16f Alignment of incisors 152f Altered passive eruption management 51 American Board of Orthodontics 15 Orthodontics 29, 30 Anchorage design of M-pendulum appliance 242 Andrews’ straight wire appliance 98 Angell’s palatal expansion device placed on maxillary teeth 155f Anterior movement of dental arche 178 Apert’s syndrome 203 Aphthous ulcer 51, 56f Apicoectomy 52 Application of laser in bonding orthodontic bracket 54 orthodontics 53

Arch length analyses 146 wire 114 bends 177 Argon lasers 50 Artistic positioning bends 177

B Baker’s anchorage 25f, 33f Ball end clasp 162 Base plate 162, 166 Begg appliance 179f Benefits of orthodontic treatment 19 Bleaching 51 Bolton’s analysis 125 study 125 Bondable brackets 109, 109f Bonded rapid maxillary expansion appliances 157, 157f Branches of orthodontics 16 British Society for Study of Orthodontics 37t of Orthodontists 15 Broca’s occipital angle 136 Broussard bracket 112 Buccal self-supported retractor 166 sweep 177

C Calculation of DAI scores 222 final scores 220

Camper’s angle 136 Canine guidance 181 retractors 165 Carbon dioxide laser 50 Care of deciduous dentition 18 Carey’s analysis 123 Caries control during orthodontic treatment 57 removal 51 Carpenters syndrome 203 Case-angle controversy 70, 148 Cast versus wrought metals 116 Cephalometric analysis 139 of developmental pattern and facial morphology in cleft palate 85 radiography 137 roentgenography 27f Ceramic brackets 108, 108f Cetlin appliance 245 Characteristic facial appearance 202 of ideal arch wire 177 Choice of teeth for extraction 150 Circumferential clasp 162 Classification of archwires 117t canine retractors 166t malocclusions 27 Cleft lip and palate formation 200 of anterior and posterior palate 201 primary palate 201

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of posterior secondary palate 201 palate 202 Cobalt-chrome-nickel alloy 118 Common syndromes associated with cleft lip and palate 203 Components of removable orthodontic appliance 162 Comprehensive orthodontic treatment 19 Contraindications of molar distalization 239 removable orthodontic appliances 161 Correcting malocclusions of dental origin 19 skeletal origin 19 Correction of cleft palate 24, 25 curve of Spee 225 Corrective orthodontics 16 Craniofacial anomalies 219 syndromes 203 Craniometry 133 Crouzon’s syndrome 203 Crowding of mandibular incisors 224 Crown angulations 180, 181 inclination 180, 181 lengthening procedure 57, 58f Crozat appliance 247t clasp 162 Curing light-activated resins 51 Current clinical use of dental lasers 51 Curve of Spee 181 Cusp embrasure contact 181

Dentistry in eighteenth century 10 sixteenth and seventeenth centuries 7 Dentoalveolar and facial asymmetries 141 Dentofacial orthopedics versus orthodontics 79 Denture stomatitis 52 Depigmentation of gingiva 57, 57f Design of appliance 248, 249 Lokar appliance 245 Destructive scanner 231f Determination of anterior ratio 125 arch length 123 width 123 discrepancy 123 overall ratio 125 Development of removable orthodontic appliances 161 Dewel’s method 151, 151t of serial extraction 152f Different types of canine retractors 166t expansion screws 158f, 159t labial bows 163t Diode laser 50, 51 Disadvantages of removable appliances 162 orthodontic appliances 162 Distal jet appliance 246t Down syndrome 203 Drawback of lingual 185 Pont’s analysis 124

D

E

Debonding of brackets by laser 57 Deciduous dentition 18 teeth 52 Deficient lower anterior facial height 90f Definition of orthodontics 14 Dental aesthetic index 221 and skeletal cross bites 141 contour appliance 227 health component 218

E-arch appliance 27, 68, 68f, 171, 171f Early mixed dentition 18 permanent dentition 18 Ectopically erupting teeth 203 Edgewise appliance 69, 70f, 172, 173f brackets 110, 110f technique 27 Edward Hartley angle 67f Elimination of abnormal oral habits 18

Enamel hypoplasia 203 reduction in orthodontics 223 Encephalocele 203 Erbium-YAG laser 49 Esthetic harmony 15, 16 Etiology of cleft lip and palate 201 Evolution of bracket 174 cephalometrics 140 clasp design 162 edgewise buccal tubes 174 orthodontic appliances 106 Expansion orthodontic appliances 159, 159t screw 157, 159 Exposure of impacted tooth 53 teeth 52 Extensive hypodontia 219 External skeletal fixation 194 Extraction of second premolar 123 Extraoral force 79, 245 appliances 17 traction 25 Eyelet clasp 162

F Fabric of human body 22 Facial angle 135 axis angle 91 of clinical crown 180 point 180 deformities 27 Factual period 77, 78 Failure of buttresses 176 Fastback appliance for molar distalization 249 Father of American Orthodontics 24, 25, 31 expansion appliances 25 modern dentistry 23 orthodontics 20 orthodontics 27 Features of fast back appliance 250 Fictional period 77

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Index

Film position and enlargement 140 Fixed orthodontic appliance 17, 17f prosthetics/cosmetics 51 rapid maxillary expansion appliances 156 Focused versus defocused beam 48 Force applied and activation of appliance 245 Founder of modern dentistry 23 Frankel appliance 189 Frankfort mandibular incisor plane angle 143 plane angle 143 Frenectomy 51 Functional mandibular displacements 141 orthopedic magnetic appliance 82, 83 study of palatal and pharyngeal structures 85 Functions of teeth 23 Fusion of teeth 203

G Gaining access for bracket placement on partially erupted teeth 55 Gingival contact 219f retraction 51 Gingivectomy 51 Gingivoplasty 51 Goldenhar syndrome 203 Grewe’s method 153 Growth and development of jaws 23

H Haas expansion appliance 159 Hard lasers 49 tissue applications 51 evaluation 89 Healing of aphthous ulcer 56 Heavy gold wire framework 161 Helical canine retractor 166 Helices of vertical holding appliance 243 Herbst’s appliance 190, 248

retention-joint appliance 155 High labial bow 163 History of arch wires 114 cephalometrics 133 cleft lip and cleft palate 197 dental lasers 47 dentistry 1 expansion appliances 154 extraction in orthodontics 145 fixed orthodontic appliances 167 interproximal enamel reduction 223 malocclusion indices 205 model analysis 122 molar distalization in orthodontics 238 orthodontic materials 120 orthodontics in Greece and Rome 44 united states of america 28 removable orthodontic appliances 160 surgical orthodontics 193 Hixon and old father method 128 Howe’s analysis—1954 124 Huckaba’s analysis 127 Hyperplasia 51 Hypothetical period 77

I Impeded eruption of teeth 219 Incisor mandibular plane angle 143 Index of complexity 220 orthodontic treatment needs 218 Indications of removable orthodontic appliances 161 various types of Frankel appliance 189 Interceptive orthodontics 16 Intercuspal position 181 Intermaxillary elastics 25, 25f Internal structure of teeth 23 Interproximal decay detection 51 enamel reduction 223 Irregularities of teeth 30, 36 Isaacson expansion appliances 157f

J Jack expansion screw 159 Jackson’s clasp or full clasp 162 triad 16 James McNamara analysis 88 Jumping bite 24

K Kernahan’s stripped ‘Y’ classification 201 Kesling model analysis 131 Kingsley’s extraoral traction appliance 155f incline plane 155f Korkhaus’ analysis 124

L Labiolingual appliance 112f Lack of incisor prominence 146 Lang brackets 112 Laser ablation of surface enamel for orthodontic bracket placement 54 beam interaction with tissue 48 classification 52 medium 47 safety 52, 58 use in dentistry 51 Late mixed dentition 18, 239 Lateral borer of tongue 56f set-back bends 177 Latest design of Klapper super spring 248 Lattice imperfections and dislocations 116 Law of canines 138 Limitations of straight wire appliance 182 Linder Hart’s measurements 124 Linderharth index 124 Lineae cephalometricae 135 Lingual brackets 110f technique 183, 183f Lokar appliance 245 Long axis of root 165 labial bow 163 Looped canine retractor 166 Lower pharynx 92

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M Magnetic strength and corrosion of rare earth magnets 82 Management of aphthous ulcer 56, 56f dentofacial anomalies 19 Mandibular plane angle 90 procedures 196 Martensitic active alloy 118 stabilized alloy 118 Maxilla 83 McNamara analysis 94t Mechanism of action of distalizing appliances 240 Mesial cuspid bends 177 Metal brackets 107, 107f Metallic bonds and crystalline structure 116 Method of determining position of upper incisor 90f straightening of orthodontic wires 115 Mill’s retractor 163, 164 Modification of Adam’s clasp 162 Modified Jackson’s clasp 161 ribbon arch 109f split labial bow 163 Molar band 24f bayonet bends 177 distalization 239 Mouth guard 19 M-pendulum appliance 241 Multiple missing teeth 203 Multistrand archwires 118 Myofunctional orthodontic appliance 18f

N Nance analysis 129 method 153 Narrowed maxillary arch 146 Nasal deformity 203 septum 200 Natural history of human teeth 23, 34, 45 Nd:YAG laser 49, 50 Nickel-titanium alloy 117, 118f Night guards 19

History of Orthodontics

Non-aqueous elastomeric dental impression material 121 Non-extraction philosophy 168 Nonosseous gingival surgery 51 Nonsyndromic clefts 202 Normal lower pharyngeal measurement 93f Normalization of gingival contour 224 Normative standards in McNamara analysis 89t Number of anchorage teeth 242

O Occlusal interference 185 Open bite appliance 190 Opening midpalatal suture 25 Optiflex archwire 117, 118 Oral lesion therapy 51 screen 190 soft tissue pathologies 52 Orthodontia and orthopaedia of face 150 Orthodontic and dentofacial orthopedics 20 and temporomandibular disorder 87 appliances 17, 186 Orthopedic appliance 17, 18f Orthosurgical teamwork 86 Osseous recon touring 51 Overcrowded teeth 15

P Palatal canine retractor 166 Pallaquium gutta 120 Paris Society of Anthropology 137 Pend-X appliance 241 Periodontal regeneration surgery 51 Periodontics 51 Permanent teeth 52 Pfeiffer syndrome 203 Pierre Robin syndrome 203 Pieter camper 135 Pin and tube appliance 68, 69f, 171, 173f technique 27 Placement of virtual gingiva 231f Plastic brackets 107, 108f Pont’s index 123

Poor facial appearance 15 oral hygiene 225 maintenance 15 Posteroanterior cephalometry 141 Post-retention survey 206 Potential soft and hard tissue applications of laser in dentistry 51 Preadjusted edgewise brackets 110, 110f Premolar basal arch width 124 diameter 124 Primary incisions 51 palate 200 Principles of space analysis 126 steriophotolithography 231 Properties of archwire 117 laser beam 48 Protrusive upper incisors 92f Pulse straightening 115 Pulsed lasers 48 Pyorrhea alveolaris 12

R Radiographic cephalometry 134 study of facial deformity 138 Range of Deflection 118 Re-activation of appliance 246 Reflection 48 Removable molar distalization splint 244 orthodontic appliance 17, 17f prosthetics 52 Removal of fibroma 51 granulomatous tissue 51 redundant gingival tissue 56 Residual ridge modification 52 Retentive components 162 Reverse labial bow 163 Ribbon arch appliance 68, 69f, 172, 172f brackets 109, 109f Risk of dental caries 15 periodontal diseases 15 Roentgen ray anthropometry of skull 137

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Index

Role of upper second molar extraction in orthodontic treatment 78 Root desensitization 51

For Personal Use Only Library Of School Of Dentistry.Tums

S Saethre-Chotzen syndrome 203 Scandinavian studies 206 Schwartz clasp 162 Scope of orthodontics 18 Second premolar extraction 147 Secondary palate 200 Self-ligating bracket 111, 111f, 113, 113f Severe crowding 225 Shape of teeth 225 Short labial bow 163 Single width bracket 111 Size of acrylic button 243 Soft lasers 49 tissue evaluation 89 modification 52 Solidification of metals 116 Southend clasp 162 Spheno-ethmoidal angles 136 Split labial bow 163 Sports guard 19 Steiner bracket 112, 112f Stereolithographic models 230f, 231f Straight wire 180 appliance 103, 180, 181, 181f

Strength of wire 119 Structural balance 15 Studies on functional appliances 93 rapid maxillary expansion 95 TMJ 96 Submerged deciduous teeth 219 Supernumerary teeth 219 System of dental surgery 29

T Temporomandibular joint 14 Thickness of button 244 Timing of orthodontic intervention 18 Timm’s schedule of activation of expansion screw 159t Tooth shape and dental esthetics 224 size discrepancy 224 whitening 56f, 57 Total space analysis 130 Treacher-Collins syndrome 203 Triangular clasp 162 Tube plates for distalization of molars 244 Tuberosity reduction 52 Tweed’s method 152 triangle 143, 143f Twin arch appliance 112f block appliance 190 brackets 111

Two palatine shelves 200 Types of Frankel appliance 189 heat treatment 117 laser 49

U Unfavorable sequelae of malocclusion 15 Upper pharynx 92 Uses in orthodontics 121 of bionatar 190

V Van der Woude’s syndrome 203 Variable bracket sitting procedures 102 Veau’s classification 201 Velocardiofacial syndrome 203 Vertical holding appliance 243 position of lower incisors 92 Vestibular screen 190 Vestibuloplasty 51

W Wearing invisalign appliance 233f Weldable brackets 109 Wescott’s expansion device 154, 154f