Orthodontics-in-Daily Practice PDF [PDF]

Zitiervorschau

Contributors R. William McNeill, D.D.S., M.S.

H. K. Terry, D.M.D.

Associate Professor of Orthodontics University of Washington School of Dentistry Seattle, Washington

Visiting Postgraduate Lecturer School of Dentistry Washington University St. Louis, Missouri

Fujio Miura, D.D.S., M.S. Professor and Chairman Department of Orthodontics Tokyo Medical and Dental University Tokyo, japan

Faustin Neff Weber, D.D.S., M.S. Professor and Chairman Department of Orthodontics College of Dentistry University of Tennessee Memphis, Tennessee

Melvin L. Moss D.D.S., Ph.D. Professor of Anatomy College of Physicians and Surgeons Professor of Oral Biology School of Dental and Oral Surgery Columbia University New York, New York

Robert A. Wertz, D.D.S., M.S. Diplomate of the American Board of Orthodontics Orthodontic Lecturer and Independent Researcher Private Practitioner in Orthodontics Kunka kee, III in ois

William Marshall Parker, D.D.S. Instructor in Clinical Dentistry University of Tennessee Memorial Research Center and Hospital Knoxville, Tennessee

• Kaare Reitan, D.D.S., M.S.D., Ph.D. The Institute of Experimental Research Dental Faculty Uriversity of Oslo oe» Norway

Raleigh Williams, D.D.S., M.S.D . Teaching Associate Northwestern University Dental School Chicago, lllinois

Earl B. Shepard, D.D.S.

D. G. Woodside, D.D.S., M.5c.

Director, American Board of Orthodontics Professor of Clinical Orthodontics Chairman, Department of Orthodontics Washington University St. Louis, Missouri

Professor and Chairman Department of Orthodontics Faculty of Dentistry University of Toronto Toronto, Ontario

Copyright © 1974 by J. B. Lippincott Company This book is fully protected by copyright and, with the exception of brief excerpts for review, no part of it may be reproduced in any form by print, photoprint, microfilm, or any other means without written permission from the publisher. ISBN 0-397-50324-5 Library of Congress Catalog Card Number 73-22136 Printed in the United States of America 134 2

Library of Congress Cataloging in Publication Data Salzmann, Jacob Amos. Orthodontics in daily practice. 1. Orthodontia. I. Title. [DNLM: 1. Orthodontics. WU400 S186pa 1974) RK521.S243 617.6' 43 73-22136 ISBN 0-397-50324-5

Preface This text on orthodontics for everyday dental practice is intended for studen ts. practitioners, and teachers. They can find here the information best suited to their immediate practical needs and can avail themselves of the wide range of information on the specialty of orthodontics. This volume will be useful for planning and instruction in continuing education programs and as a handbook of ready reference in daily practice. Practical instruction is included on occlusal guidance of the developing dentition in the young child to obviate extensive orthodontic intervention later. Stress is laid on the construction and use of preventive-interceptive appliances. Practical cases are discussed and illustrated. Orthodontic treatment of adults is now an important phase of practice. This subject is presented and illustrated for the treatment of malocclusion and for the alignment of teeth into favorable positions as abutments in restorative dentistry. A method is discussed for establishing vertical dental height before undertaking restorative dentistry in occlusal rehabilitation. Techniques are presented in a stepby-step sequence. The related basic medical and dental sciences are explained when they have immediate bearing on diagnosis and treatment. I am proud to be associated with the contributors to this text whose names are listed alphabetically and not necessarily according to the relative importance of their contributions. The practice of orthodontics now requires the expertise of those who have made special contributions to the specialty. I have included these contributors for this reason. I am deeply indebted to them. A detailed account of interceptive-preventive orthodontic therapy is contributed by Dr. Faustin Weber. He addresses himself to the general practitioner and pedodontist as well as to the student and practitioner of orthodontics. Indications and contraindications are given for treatment with and Without the use of appliances. The mandibular first and second premolars shift distally while the permanent second molar remains stationary, owing to interference of the elongated maxillary permanent first molar. (Bottom row, lejt) The mandibular first and second premolars remain stationary while the second molar is shifting mesially into the extraction space. (Center) Distal shifting of the second premolar and mesial shifting of the second molar closed the mandibular extraction space. The first premolar remained stationary, and a space has been opened between the first and second premolars. (Right> The space of the extracted maxillary permanent first molar is completely closed. Closure was effected by distal shifting of the teeth anterior to the extraction space and mesial shifting of the second and third molars.

Maxillary midline diastemas can be a normal conditions from infancy until 10 years of age or until the

canines have erupted. The following can be the cause of abnormal diastemas: L Tongue, finger, or lip pressure habits 2. Endocrine dysfunction - acromegaly 3. Agenesis of tooth germs 4.A short upper lip accompanied by abnormal overjet of the maxillary incisors

Fig. 9-16. Outline drawing showing normal dental arches

(heavy solid lines) and shifting of the teeth following extraction of the permanent first molars and closure of the space (thin broken lines). In the maxillary arch, there is a shifting of the incisor teeth to the side from which the permanent first molar was extracted, a slight distal shifting of the canines and premolars, and a decided forward shifting of the second and third molars. At the same time, there is a flattening or collapse of the arch lingually on the side of the arch from which the first molar was extracted. In the mandibular arch, there is a slight shifting of the incisor teeth to the side from which the permanent first molar was extracted. There is also a lingual collapse of the canine and the incisor teeth which results in an increased overbite. The premolars rotate and incline as they shift distally and show spacing between them. The second and third molars shift mesially and show some rotation and much forward inclination, but there is no collapse of the premolars and the molars in a lingual direction.

70.

Midline Deviations· 117

Fig. 9-17. (Top) Left-side roentgenogram shows distal shifting of the mandibular first premolar and canine following loss of the deciduous second molar without a succeeding second premolar. (Top, right) The deciduous second molar on the right side is still in position; its roots are resorbed but no succeeding premolar is present. There is no space separating the mandibular first premolar and canine, as on the left. (Bottom) Pocket formation after loss of permanent first molars and shifting of adjacent teeth.

5. Deficiency of tooth structure, such as missing or dwarfed lateral incisors 6. One or more abnormally large or deformed teeth in the anterior region of the mouth that interfere with or disturb normal maxillary tooth alignment.

Space Loss Loss of mesiodistal space involving the teeth is caused by the following: 1. Loss of tooth substance from the mesial or distal aspects of teeth - extraction, premature loss, caries, accidental trauma 2. Faulty contour of fillings 3.Loss of deciduous teeth coincident with missing permanent tooth germs 4. Disturbances of occlusion following premature loss of deciduous teeth before the permanent successors are ready to erupt 5. Deciduous teeth lost through traumatic injuries can damage the unerupted underlying permanent teet~. Accidental loosening of primary teeth rarely affects the permanent successors.

Loss of Permanent Teeth Loss of permanent teeth can produce various types of shifting of the adjacent teeth, initiating or modifying existing malocclusion, depending on the type of occlusion originally present in the mouth.

Occlusal changes after loss of permanent first molars include the following: 1. Dental arch collapse 2.Teeth adjacent to the extraction space show a tendency to rotate, incline, and shift their position. The premolars usually shift distally while the molars shift in a mesial direction. 3. The median line of the teeth tends to shift in the direction of the side from which the first permanent molar has been extracted. 4. An increase in the incidence and degree of intensity of dental caries 5. Loss of the permanent first molar while the deciduous second molar is still in position can cause the second premolar to erupt distally in the space left by the extracted first molar. Occlusal changes following extraction of perrnanent first molars without orthodontic treatment can be summarized as follows: In the Maxilla. Closure of the space after extraction is caused by distal shifting of the premolars and mesial shifting of the molars. In Class I (Angle) malocclusion with normal molar relationship, the malocclusion may change to Class II, Division 2 subdivision. There may be buccoversion of the premolars (occasionally of the canines) and lateral incisors on the side where the extraction occurred. When mandibular permanent first molars are lost in Class I (Angle) cases, they may change to Class II, Division 1 or Division 2 subdivision, depending on whether the loss is unilateral or bilateral and on the

118 . Etiologic Factors in Malocclusion Fig. 9-18. Orodigital habits can contribute to malocclusion. (Left, top) The infant bites two fingers of each hand. (Center) Protrusion and openbite develop on the side on which this girl habitually sucks her finger. (Bottom) This boy pulls on his mandible. The mandible protrudes, and he has crossbite and open bite. (Opposite) Three examples of how thumbsucking can effect the occlusion.

relationship of the lower Lip to the maxillary incisors. If the lip rests under the maxillary incisors, the change is to Class II, Division 1 subdivision. If the lip closes normally over the maxillary incisors, the change is to CLass II, Division 2 subdivision. Loss of maxillary first molars in Class II, Division 1, (Angle) cases does not result in self-correction

because of the comparatively small amount of distal shifting of the premolars and the relatively greater mesial shifting of the adjacent second molars. The relative protrusion of the maxillary incisors may be increased because of the distal shifting of the premolars and lingual collapse of the mandibular incisors. When one permanent first molar is extracted in

Supernumerary Teeth· 119

Fig. 9-18 (Continued)

C4!ss II, Division 1 malocclusion there is a tendency for the maLocclusion to become a subdivision of the same classification. Loss of maxillary permanent first moLars in Class III (AngLe) cases (mesial relation of the mandible) increases the malocclusion. If a permanent first molar tooth is lost before the second premolar erupts, there is a tendency for the second premolar to fall into the alveolus of the ex-

tracted permanent first molar and to erupt distally, producing spacing between the premolars. SUPERNUMERARY TEETH Supernumerary teeth can be responsible for delayed eruption, norieruption, and spacing of the teeth. Early removal of supernumerary teeth is important to prevent dental irregularities and dental arch malrelationships.

120 . Etiologic Factors in Malocclusion Fig. 9-19. Open bite in an adult caused by lower lip sucking and posture of the tongue over the incisal surfaces of the mandibular incisor teeth. Note. The occlusion of the teeth in the lateral jaw segments is not disturbed. The habit caused spacing and protrusion of the maxillary incisor and canine teeth.

The following can serve as a guide in radiographic diagnosis of supernumerary teeth: 1. The supernumerary tooth shows a dense area on the film.

2. The enamel of the supernumerary tooth may be seen on the radiogram. 3. The pulp chamber of the supernumerary tooth is visible on the radiogram. 4. A radiolucent line of demarcation of the tooth sac is visible on the radiogram.

DENTOFACIAL PRESSURE HABITS Pressure habits that interfere with normal growth and jaw function include finger-sucking, tongueand lip biting, biting on firm materials, and bruxism.

Thumb- and Finger sucking There is a positive correlation between thumb- and finger sucking and malocclusion. This does not

mean that every child who sucks a thumb or finger will develop malocclusion. Forceful methods of preventing thumb- or finger sucking can produce psychological distress in children. Thumb-sucking practiced after permanent incisor eruption can cause openbite, maxillary incisor protrusion, crossbite, distoclusion of the mandibular dental arch, and constriction of both dental arches. The type of malocclusion depends on bone density, on the intensity, duration, frequency, and method of sucking, and on which finger is sucked. Malocclusion caused by thumb-sucking will correct itself if the habit is stopped while the child is young. If the maxillary incisors rest on the lower lip when the jaws are approximated, the occlusion will not correct spontaneously. A personal appeal to the child, preferably by someone other than the parent, for cooperation in eliminating the habit is important. The child thus is given a sense of responsibility for the ha bi t- breaking effort.

Dentofacial Pressure Habits' 121 TABLE 9-1. CONDITIONS THAT MAY RESULT FROM LOSS OF A SINGLE TOOTH" (I. HIRSCHFELD) Food impaction, entailing over 20 ill-effects, including caries and interproximal disease Periodontal disease, or accentuation of same Cervical caries (?) Traumatic. Acute or chronic inflammation Pulp involvement Referred occlusion pain { { Devitalization Root Cervical hypersensitiveness exposure { Wasting (abrasion, erosion or cervico-abrasion) Caries A. Shifting (mesiodistal

1. A break in continuity of the dental arch

2. Elongation

3. Diminished function (Local)

Accentuation of depth of approximal gingival crevice Excessive mobility or buccoTraumatization of tongue Interdental Unattractive appearance lingual) spacing Speech defect (social and economic disadvantages) Traumatization of tongue (inviting malignancy) Malposition of frenum { Gingival recession labially instead of Accentuation of pyorrheal destruction interproximally Interference with treatment Temporomandibular disturbances Approximation of jaws Traumatic occlusion and { Gingival traumatization anteriorly T. {FOOd impaction B. orsion Traumatic occlusion C. Food impaction other than that caused by shifting or torsion R . I) { Cervical hypersensitiveness

I

D. oot exposure (approxima Cervical caries E. Traumatization of tongue (inviting malignancy) A. Traumatic occlusion B. Food impaction C. Root exposure D. Proximal bifurcation exposure rendering prognosis of pyorrheal infection negative E. Shifting F. Satisfactory restoration made difficult { Atrophy Gingivitis Lowering of resistance to infection A. Diminishing of periodontal circulation B. Unhygienic condition Hypersensitiveness Caries { C. Retardation of occlusal wear D. Excessive occlusal wear on one side of mouth (inharmonious occlusal relation)

• Hirschfeld, Isadore: J. Am. Dent. Assoc. & Dent. Cosmos, 24:67-82, 1927.

Lip Biting Lip biting or sucking may occasionally develop as',a variant of or a substitute for thumb- or finger suaking. In lip sucking the lower lip is turned inward and is caught between the maxillary and mandibular teeth and pressure is exerted by the lip. The force produced by the lip can move the maxillary incisors labially and the mandibular incisors lingually. Tongue Sucking Tongue sucking may be caused by macroglossia.

Tongue sucking or fingernail biting may be a substitute habit when thumb-sucking is peremptorily prohibited.

Nail Biting Fingernail biting shows a marked increase in children after 6 years of age. There is a constant upward trend until 10 years of age for girls and 12 years for boys. The habit usually is replaced after adolescence by lip biting, gum chewing, or smoking. Clinical examination of the incisor teeth in finger-

122 . Etiologic Factors in Malocclusion Fig. 9-20. The face of this 13year-old girl is asymmetrical owing to finger-sucking and hand pressure. She had practiced this habit since early childhood. The side view shows how pressure was applied to the face and mandible. Her occlusion is fairly normal, but shows distortion from pressure. There is an opening in the bite where the fingers are inserted into the mouth.

nail biters indicates that the habit is responsible for openbite, and rotation of the mandibular incisors.

teeth. Fractured and missing teeth can produce the same effects on the occlusion as premature tooth extraction.

Traumatic Occlusion Force exerted on the occlusal or incisal surface of "" tooth is translated as traction on the periodontal ligament. When the force is greater than it can withstand, some of the periodontal ligament may be destroyed. The tooth may be loosened, or, if lateral trauma is absent, it may actually become ankylosed. Caries Caries can destroy the mesiodistal contour of

Bruxism

Bruxism can occur during sleep and in waking hours. The most important factor is psychological or emotional tension. It can be initiated by local factors including cusp interference, loose teeth, high fillings, and any continuing stimulus to the afferent nerve endings in the periodontal tissues, which normally are associated with the reflex arcs of the rhythmical movements of mastication. Children who suck their thumbs or bite their nails may

Bibliography' 123

switch to grinding their teeth as adolescents. Treatment consists of psychiatric intervention and the use of an activator or a teeth protector. MANDIBULAR INCISOR CROWDI G Crowding of mandibular incisors can be caused by the following: 1. Difference in width between the well aligned maxillary incisors and wider mandibular incisors that are crowded in the space lingual to the maxillary incisors 2. Deep overbite that interferes with mandibular incisor alignment 3. Lip pressure in lip-biting causing deviation from regular alignment 4. Relapse after the incisors have been moved into increased procumbency 5. Mesial shifting of the permanent molars that encroaches on space required by the premolars after premature loss of deciduous molars. The premolars in turn encroach on the space required for the canines and incisors. Fig. 9-21. Fingers and toes of a girl nail biter.

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10 Dentition Anomalies and Malocclusion NUMERICAL VARIATIONS OF TEETH relation to jaw or quadrant), mandibular central incisors, and maxillary first premolars. First molars, mandibular canines, and maxillary central incisors rarely fail to appear. Partial or total absence of tooth germs occurs more frequently in the mandible, while supernumerary teeth occur more frequently in the maxilla, especially in the anterior region.

Agenesis of teeth occurs about ten times as frequently as supernumerary teeth. The age of a person when supernumerary teeth form or erupt varies. Among causes of supernumerary teeth are the following: hypergenesis of the epithelial cord, heredity, and developmental aberrations such as cleft palate. Supernumerary teeth include the following: 1. Peg teeth with conical crowns, usually found at the midline between the .perrnanent maxillary incisors. 2. Multicusped, geminated teeth and teeth of unusual size. 3. Duplicate teeth in size and appearance-usually lateral incisors and premolars. Anodontia, the congenital absence of all teeth, is extremely rare. Oligodontia vera, a condition in which a number of teeth fail to form, can be related to ectodermal disturbances and may show itself in the deciduous or the permanent dentition. The causes of anodontia and oligodontia are as follows: 1. Hereditary ectodermal dysplasia 2. Cleft palate, micrognathia, or macrognathia 3.Acute, chronic, or pyogenic inflammations that destroy the tooth germ 4. Birth injuries, rickets, and diseases of the mother during pregnancy 5. Endocrine disturbances

Delayed Eruption Retarded eruption of teeth can be caused by the following: 1. Ectopic eruption 2. Abnormal distance of tooth germ from its usual place of eruption 3. Malformation of teeth 4. Presence of interfering supernumerary teeth 5. Trauma or infection of tooth germs 6.Displacement of tooth germs or teeth by a neoplasm 7. Ankylosis of the tooth with the jaw bone 8.Systemic diseases such as metabolic and endocrine disturbances 9. Space closure by adjacent erupted teeth 10. Heredity.

ECTOPIC ERUPTION Ectopic eruption is the abnormal eruptive position of a tooth. Ectopic eruption can be caused by the following: delayed exfoliation of deciduous teeth; presence of supernumerary teeth, cysts, and other infections; prolonged retention or premature extraction of deciduous teeth without space maintenance; and misplaced tooth germs. The prolonged retention of deciduous canines that fail to show root resorption can interfere with permanent canine eruption. The permanent canine may erupt high on the labial surface of the alveolar process. Ectopic eruption of second premolars in the mandible is usually found when loss of permanent first

Agenesis of Teeth The frequent agenesis of the maxillary lateral incisors can be linked to an abnormality occurring at the lateral sulcus of the palate. Agenesis of mandibular central incisors may be an indication of obstruction or abnormal ossification at the mandibular symphysis. Agenesis is most frequent in the third molars and is seen with decreasing frequency in maxillary lateral incisors, second premolars (without cor-

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Ectopic Eruption· 127 Fig. 10-1. Roentgenograms show apparent agenesis of second premolar follicles in a 7V2-year-old patient. At 9Y1 years, there is evidence of second premolar crowns forming. At lOV2, the second premolar crowns are calcifying; and at age 13 V2 calcification is continuing.

molar occurs before the second premolar erupts. In these cases, the second premolar is often found to Jrupt in the space formerly occupied by the extracted permanent first molar, while a space about the width of the extracted molar separates the second premolar from the first. Occasionally the second premolar may fail to erupt altogether. Ectopic eruption of first permanent molars that brings them too far mesially can cause the roots of

the second deciduous molars to be resorbed prematurely. Occasionally the eruptive force of the permanent molar will cause exfoliation, or elevate the second deciduous molar into supraclusion. Third molar ectopism can be caused by lack of alveolar tuberosity growth and by micromandibular growth. It is questionable whether the eruptive force of the third molars can force the teeth anterior to them out of alignment. When the second molar has

128 . Dentition Anomalies and Malocclusion

Fig. 10-2. Roentgenographic evidence of agenesis of tooth follicles: (top row) maxillary permanent lateral incisors and canines are missing. (Center) The maxillary left central incisor was lost accidentally; the maxillary first premolars and canines are missing. (Bottom row) Permanent mandibular lateral incisors are absent. The mandibular right deciduous second molar is displaced into the alveolar process by the inclined permanent first molar (left side).

been moved distally by orthodontic means onto the path of eruption of the third molars there can be recrowding. -Migration of the mandibular canine to the opposite side occurs when the tooth germ is situated at the symphysis of the mandible. As the tooth develops horizontally, it finally erupts or is impacted on the side opposite its normal position. Fusion of teeth may involve the crowns only, the roots alone, or the entire tooth. Union of the tooth germs during the developmental process is considered to be responsible for teeth fusion.

IMPACTIONS An impacted tooth is one that is prevented from eruptirig into position because of malposition and contact with other teeth. Causes of impaction are hereditary factors, space closure after early loss of deciduous teeth, and prolonged retention of deciduous teeth. Although impacted deciduous teeth are rare, any tooth in the mouth may become impacted. Teeth that become impacted, in order of decreasing frequency, are mandibular third molars, maxillary third molars, maxillary canines, mandibular second

Impactions' 129 Fig. 10-3. The roots of an ll-year-old girl's mandibular second deciduous molar were resorbed. Her second premolar is absent.

Fig. 10-4. (Bottom) Compare this second deciduous molar that likewise has nosecond premolar successor. The deciduous molar that shows resorption has received fillings; the one without resorption has not been filled. Root resorption in deciduous teeth that are without permanent successors occurs more frequently when the deciduous teeth are filled and when they are not below the line of occlusion.

premolars, and maxillary second premolars. Unilateral impactions of third molars are somewhat more frequent than bilateral. Maxillary canines show a frequent tendency to unilateral impaction. Impacted teeth should be examined to determine whether the periodontal ligament is intact before an attempt is made to bring them into occlusion. When the periodontal ligament is absent, the roots are ankylosed and orthodontic tooth movement without tooth dislodgement is not possible.

Impaction of Third Molars The normal position of the calcifying crown of the mandibular third molar faces mesially. Slight aberration in posterior growth of the mandible can cause the tooth to be impacted against the distal aspect of the second molar. The maxillary third molars are malpositioned less frequently than are the mandibular ones because the direction of eruption of the maxillary molars is backward and downward. Maxillary third molars may erupt buccally to the second moLars. However, the thickness of the mandibula.r bone usually prevents lingual and buccal deviation of the erupting third molar. Diagnosis of impacted third molars should take into consideration the age of the patient and the stage of eruption of the dentition as a whole. Diagnosis is more certain in the late adolescent stage. The positional changes in third molars brought about by jaw growth and eruption can eliminate apparent

Fig. 10-5. Agenesis of mandibular permanent central incisor teeth.

130 . Dentition Anomalies and Malocclusion

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Fig. 10-6. Casts of a girl of 10 years and 5 months show multiple ankyloses of deciduous and permanent teeth and arrested tooth eruption. The alveolar process is not growing. (Top left) On the right side the maxillary permanent first molar (1) is not completely erupted. (2) The mandibular 2 deciduous second molar is below the line of occlusion. (Top right) (1) The maxillary permanent first molar has not erupted. The mesiobuccal cusp of the maxillary deciduous second molar (2) is showing through the alveolar mucosa, and the maxillary deciduous first molar is above the line of occlusion. The mandibular second deciduous molar (3) is below the line of occlusion. (Bottom left) The anterior view shows an abnormally deep overbite. The occlusal view shows the mesiobuccal cusp of the maxillary left deciduous second molar (1) pushing through the gum. The permanent first molar (2) is almost wholly unerupted. On the right side of the maxilla the occlusal surface of the permanent first molar (3) has erupted slightly above the level of the alveolar mucosa. The 2 mandibular right and left deciduous second molars are seen to lie below the line of occlusion. (Bottom) side (left) The mandibular second deciduous molar (1) lies below the line of occlusion and the second premolar lies directly below. In the maxilla, the permanent canine (2) is erupting mesially to the deciduous canine and the permanent first molar (3) has not reached the line of occlusion. (Right) On the left side, the maxillary permanent second molar (4) has not erupted; likewise the permanent first molar, (5) except for the mesiobuccal cusp, which shows through the gum. The deciduous second molar (6) is ankylosed, and its crown, except for the occlusal surface, is covered by bone and gum tissue. The 4 second premolar crown (7); the first pres molar (8); the first deciduous molar (9); 6 7 the permanent canine (10); and the des ciduous canine (11) are shown. The man~o dibular deciduous second molar (12) lies below the line of occlusion, and the second 12 premolar is directly below it.

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impactions of these teeth. Radiographic examination of the third molars requires occlusal and lateral jaw films to check on buccal deviations. ERUPTION ANOMALIES Ankylosis of teeth is a fusion of the cementum

with the surrounding alveolar bone. Tooth ankylosis may occur either before or after eruption of the tooth and can be found in the deciduous and the permanent dentitions. Ankylosis of deciduous teeth can be caused by the deposition of bone into the partially resorbed roots. Biederman found tooth ankylosis to occur more than twice as often in the man-

Eruption Anomalies . 131

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Fig. 10-7. Agenesis of permanent maxillary second and third molars.

dible as in the maxilla, and far more in the deciduous than in the permanent dentition. The teeth most frequently ankylosed are the mandibular second deciduous molars; then, in decreasing order, the mandibular first deciduous molars, the maxillary second deciduous molars, and the maxillary first deciduous molars.

Re-enclosure of Teeth in the Jaws There are two types of teeth found imbedded in the

Fig. 10-8. (Top) Right mandibular 2nd molar eruption is interfered with by 3rd molar crown. Note. A brass ligature separating wire was used to move the 3rd molar crown away from the 2nd molar. (Bottom) Right, the 2nd molar is erupting and its crown is now above that of the 3rd molar which requires axial correction.

Fig. 10-9. (Left) The second molar is impacted against the first molar. (Center) A band with an extension looped auxiliary spring is used to move the second molar away from the first molar and to rotate the crown occ1usally. (Right) The second molar is in position; the third molar is impacted. jaw bones: those that erupted but were later reenclosed, the so-called "submerged" teeth, and those that never erupted. A re-enclosed ("submerged") tooth is one that fails to maintain its position in the developing occlusion. It may become partially or completely enclosed by the alveolar mucosa and the alveolar process in the growing child. Failure of these teeth to maintain their height is ascribed to ankylosis of surrounding bone and the tooth. As the alveolar

process continues to grow, what was formerly alveolar process becomes part of the body of the maxilla or the mandible.

Prolonged Retention of Deciduous Teeth Prolonged retention of deciduous teeth beyond the chronologie age when these teeth normally are shed is attributed to the following: 1. Absence of permanent successors

132 . Dentition Anomalies and Malocclusion 72.

J Fig. 10-10. The mandibular left canine lies across the incisor teeth. An attempt to expose canine could harm the incisor teeth. 2. Malposition of the erupting permanent teeth 3. Impaction of permanent teeth 4. Ankylosis with the alveolar bone.

Premature Exfoliation Premature exfoliation of teeth occurs in premature root resorption; keratosis palmaris et plantaris in which there is loss of alveolar process; reticuloen-

Fig. 10-11. Supernumerary teeth interfere with the eruption of permanent central incisors. This 11-yearold patient's deciduous central' incisors are still in position. The permanent lateral incisors have erupted.

Fig. 10-12. (Left) Supernumerary teeth are situated above and below the unerupted maxillary central incisor in a child 8 years old. (Right) The maxillary central incisor erupted after supernumerary teeth were removed. Removal of supernumerary teeth close to unerupted teeth requires special care to avoid injuring and displacing them.

73.

Fig. 10-13 (A) (Top) A and B show maxillary 4th molars. C shows a horizontal impaction of a mandibular right 3rd molar. (Center) Supernumerary premolar teeth. (Bottom) Left, peg tooth in palate. Right, peg teeth in close proximity to maxillary left permanent central and lateral incisor teeth. Attempts to remove the supernumerary teeth can interfere with the vitality of the adjacent incisor teeth. (B) Three supernumerary premolars.

Eruption Anomalies· 133

134 . Dentition Anomalies and Malocclusion dotheliosis which shows osteolytic lesions developing about the roots; and acrodynia osteonecrosis; and in severe bruxism when the teeth are forced out of the alveolar process. Hypophosphatasia with tooth loss manifests itself in the first few years of life and is more severe in early infancy. Early maturation, early eruption, and early exfoliation of both the deciduous and the permanent teeth have been reported to occur in otherwise normal patients. Traumatized Teeth Trauma of a tooth may cause obliteration of the pulp canal, resorption at the pulp walls, or resorption of the tooth surface. The extent of external and internal resorption depends on the extent to which the hard tissues have been damaged by loss of nerve and blood supply. Asymmetric Root Resorption Asymmetric root resorption of the deciduous molar roots may show one root only to be resorbed. Such deciduous teeth should be extracted to prevent malposi tion of the succeeding permanent tooth when it is about to erupt. Fig. 10-14. In 1961, at age 10, this patient's permanent canines were in the normal eruption space. A year later they began to erupt ectopically and still a year later, they were impacted, (Courtesy M. L. Feldman)

Retention of Deciduous Tooth Roots Retained deciduous roots are more common in the mandible than in the maxilla and are found in

Fig. 10-15. (Left) The deciduous mandibular right lateral incisor and canine are geminated as the radiogram below shows, The right mandibular permanent incisor follicle failed to form, a condition frequently seen with geminated deciduous teeth. (Right) Casts show geminated maxillary central and lateral incisors. The radiogram shows the geminated deciduous left central and lateral incisors, All permanent incisors are present.

Root Resorption and Orthodontic Therapy· 135 the jaw to be covered by a thick layer of hyperplastic cementum. Root Resorption of Permanent Teeth Factors responsible for root resorption of permanent teeth are as follows: 1. Replanted teeth 2. Impacted teeth 3. Pulpless teeth 4.Fractured teeth that were allowed to remain in the mouth without pulp therapy 5. Teeth in close proximity to tumors and cysts of the jaws 6. Teeth subjected to excessive trauma 7.Diabetic disturbances, endocrinopathies or other systemic diseases can show high susceptibility to resorption of bone and teeth.

ROOT RESORPTION AND ORTHODONTIC THERAPY Root resorption can occur in the presence or absence of orthodontic tooth movement. In orthodontically treated teeth root resorption is usually microscopic in extent and is arrested when treatment is completed or discontinued. If it is not extensive root resorption does not interfere with the continued functional efficiency of the teeth. Frequent radiographic examination of teeth undergoing orthodontic tooth movement is advisable.

Root Resorption and Traumatic Occlusion Under abnormal occlusal stress the supporting structures of the tooth or teeth may become reinforced, enabling the teeth to withstand the excessive stress. Conversely, the supporting tissues may be damaged and the tooth may be loosened if it is unable to resist the force. Internal resorption of teeth, characterized by the socalled pink spot, is caused by vascular changes in the pulp. Internal resorption may follow marginal gingivitis with the formation of granulation tissue in the pulp chamber which resorbs the tooth structure. Resorption of "Blocked Out" Teeth. Insufficient rodm for the permanent lateral incisor to erupt can cause root resorption and premature exfoliation of the deciduous canine. The permanent lateral then erupts in the eruption path of the permanent canine. As the first premolar erupts, it occupies the rest of the space intended for the erupting permanent

Fig. 10-16. (Top) The erupting mandibular third molars are in mesioversion in a 15-year-old. (Center) At age 161h the left mandibular third molar has erupted into normal occlusion, and the right mandibular third molar shows improved position for eruption. (Bottom) The maxillary and mandibular third molars are in normal occlusion fully erupted. In the course of eruption third molars may show increased torsi version and may eventually become impacted. In this case, the third molars erupted into normal occlusion. The decision to extract ectopically erupting or impacted third molars during the period of dental development should be postponed until a series of examinations confirm the diagnosis.

canine which, consequently, is blocked out. The canine usually then erupts labially as the so-called high canine. Second premolar impaction can occur when the permanent first molar causes resorption of the roots and subsequent exfoliation of the second deciduous molar. The permanent first molar

136 . Dentition Anomalies and Malocclusion Fig. 10-17. (Top) Premolars erupted prematurely after the deciduous molars were lost early. (Center) There is delayed calcification in the right mandibular permanent second molar; the left one is unerupted. (Bottom) Radiograms of an t l-year-old boy who never developed permanent first molars. The permanent second molars are calcifying but are still unerupted.

Fig. 10-18. (Left) Ectopic eruption of the first and second premolars was caused by overretention of the deciduous first and second molars. (Right) Prolonged retention of deciduous molars caused buccal cross bite.

Root Resorption and Orthodontic Therapy' 137 Fig, 10-19, (Top) Geminated permanent lateral incisors interfere with mandibular permanent canine eruption, (Right) The geminated tooth has been separated; half was extracted, and the other half was left in the jaw. There is enough space for the permanent canine to erupt. (Courtesy of N. C. Gaston) (Center) An overretained deciduous lateral incisor caused the permanent successor to erupt ectopically. (Bottom left) An overretained incisor crown interferes with the resorption of the permanent lateral incisor. (Right) Failure of the deciduous lateral incisor to resorb interferes with the eruption of the permanent lateral incisor.

Fig, 10-20. The patient is a girl age 15 years. Retained maxillary canines are about to erupt buccally.

138 . Dentition Anomalies and Malocclusion

Fig. 10-21. (Top left) The radiogram shows extreme resorption of the right mandibular deciduous second molar with the succeeding second premolar ready to erupt. (Top right) A radiogram of the left side shows that the roots of the second deciduous molar are only partially resorbed, and the crown of the succeeding second premolar is not completely formed. The rate of root resorption of deciduous teeth and development of the permanent teeth on each side of the jaws of the same patient may show wide variation. (Bottom left! The radiogram shows attachment of the mucosa to the crown of the deciduous second molar after the roots were resorbed, causing prolonged retention of the deciduous molar crown and interference with the eruption of the second premolar. (Bottom right) The radiogram shows an unresorbed root of a mandibular deciduous lateral incisor interfering with the proper occlusal alignment of the erupted permanent lateral incisor. Roots of deciduous incisors may fail to resorb and can mechanically interfere with the eruption of permanent teeth.

Fig. 10-23. (Top) The maxillary permanent first molar is caught under the deciduous second molar. (Bottom) Three years later, the permanent first and second molars have erupted. The space for the second premolar is closed, and the second premolar IS impacted. Freeing the permanent molar from the second deciduous molar and space retention could have prevented this malocclusion.

Fig. 10-22. (Top) Alveolar bone overlies the crown of the premolar tooth. The premolar still has to complete calcification of its crown and begin calcification of its root. The deciduous second molar shows root resorption but should be retained in position until the premolar is ready to erupt. (Bottom) Early loss of the deciduous second molar has hastened the eruption of the premolar before it actually was ready.

Root Resorption and Orthodontic Therapy . 139 Fig. 10-24. An odontoma is interfering with the eruption of the mandibular canine.

74.

Fig. ·10-25. (Left) A peg tooth, also known as a mesiodens, is between the maxillary central incisors. (Right) Supernumerary teeth in the maxillary incisor area crowd the maxillary incisors.

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Fig. 10-26. Pretreatment view (top left) and cast (center) show that the lateral incisors are distal to the canines. After treatment, the incisors are aligned, but the lateral incisors were allowed to remain distal to the canines (bottom left, right).

140 . Dentition Anomalies and Malocclusion 75. Fig. 10-27. (Top) Transversion of maxillary permanent canine (0 and premolar (P) teeth: the roentgenogram shows transversion of the canine and premolar teeth. (Center) Right and left canines erupt between the first and second premolars. (Bottom) A permanent lateral incisor erupts under the deciduous first molar: (A) deciduous first molar; (B) permanent lateral incisor; (C) deciduous canine.

Fig. 10-28. Radiograms show agenesis of all four permanent canines in a 15-year-old boy with hypogonadism and hypopituitarism. The four deciduous canines are in position and show failure of root resorption.

Bibliography· 141 then erupts mesially usurping some of the space intended for the second premolar. With the eruption of the first premolar before the second premolar erupts, the space is occupied and the second premolar is impacted or may erupt lingually. Anomalies of Tooth Arrangement. In the permanent dentition those teeth most commonly out of position are the third molars; then, in order of decreasing frequency, the maxillary lateral incisors, the mandibular incisors, the second premolars, and the second molars. The first molars and first premolars are rarely out of position.

BIBLIOGRAPHY Book, ]. A.: Clinical and genetical studies of hypodontia. Am. J. Hum. Genet., 2:240, 1950. Boruchov, M. J" and Green, L. J,: Hypodontia in human twins and families. Am. J, Orthodontics, 60:165, 1971, Bradlow, R.: An inheritance of dwarfed or absent maxillary lateral incisors in three generations. Internat. ]. Orthod. & Dent. Child., 21:439,1935. Brekhus, P, J., Oliver, C. P., and Montelius, G.: A study of the pattern and combinations of congenitally missing teeth in man, ]. D. Res., 23:117, 1944. Bruce, K W.: Dental anomaly: early exfoliation of deciduous and permanent teeth. J.AD,A, 48:414, 1954. Bruszt, P.: On the migration of lower canines to the

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opposite side of the mandible. Acta Morph. Acad. Sci. Hung., p. 7, 1956. Del Boca, R.: Considerazioni su cinque casi di transposizione dentaria. Minerva Stomatol., 8:115, 1959. Foster, T, D., and Taylor, G. S.: Characteristics of supernumerary teeth in the upper central incisor region, D. Practitioner., 20:8, 1969. Gardiner, J. H.: Supernumerary teeth. Dent. Practitioner, 2:63, 1961. Millhon, Jerry A., and Stafne, E. c.: Incidence of supernumerary and congenitally missing lateral incisor teeth in eighty-one cases of harelip and cleft palate. Am. ]. Orthodontics, 27:599, 1941. Sabes, W. R., and Barthold i, W. L.: Congenital partial anodontia of permanent dentition: a study of 157 cases. J. Dent. Child., 29:211, 1962. Steinberg, A. G., Warren, J. F., and Warren, L. M.: Hereditary generalized microdontia. J. D. Res., 40:58, 1961. Tannenbaum, K A, and Alling, E. E.: Anomalous tooth development, case reports of gemination and twinning. Oral Surg., Oral Med., & Oral Path., 16:883, 1963. Yolk, A.: Untersuchungen zur Zahnunterzahl, Fortschr. Kieferorthopad ie, 24:202, 1963. Welsh, J. P.: The psychogenesis of bruxism. J. Periodont., 36:417, 1965. Warner, G, R, Orban, B" Hine, M. K, and Ritchey, B.: Internal resorption of teeth: interpretation of histologic findings. J.AD.A, 34:468, 1947. Wegner, H.: Uber hypodontia vera der milch und ersatzzahne bei vererbter ekto- und mesoderm- dysplasie. Deutsche Zahn. Ztschr., 17:1019, 1958.

11 Examination of the Patient The child orthodontic patient can be assessed in six parameters. The (1) amount, (2) rate, and (3) direction of dentofacial growth and function of the stomatognathic system over (4) intervals of time, must be ascertained to determine the status, progress and (as far as possible) the terminal state of the occlusion in the individual child. Function (5) is another important parameter in measuring the development of the dental occlusion, and (6) psychoneurogenic endowment of the child is a dimension which frequently determines whether the patient will cooperate in the treatment of malocclusion.

lation and centric occlusion. Midline discrepancies should be noted. When deviations in swallowing are suspected, the patient may be given a biscuit to eat so that the method of chewing and swallowing can be observed. The teeth and gingival tissues should be examined. Speech, postural, and functional aspects of the tongue, the position of the lips in relation to the teeth, and the rest position and postural positions of the mandible should be noted. Serial Examinations. Serial examinations are of special value during the deciduous- and mixed dentition periods. The roots of deciduous teeth may be resorbed abnormally, or the deciduous teeth may be prematurely lost or retained too long. Interferences with continuing normal dentofacial development should be noted. Histories. Medical and dental histories of the patient and his immediate family provide information on genetic endowment, postnatal development, and growth experience. Medical history obtained from the mother usually is not reliable. Hospital records and information obtained from the family physician can be useful when systemic etiologic influences on dentofacial abnormalities are suspected. Height and weight measurements provide a clue to physical growth and maturation. Posture. Correction of throat and neck muscle function is important in treating some malocclusions and in avoiding relapse after treatment. Good posture is comfortable and requires little effort to maintain. Conformation to a single postural pattern is of no value. Skeletal Signs. Skeletal proportions are indicators of maturation. At birth the ratio of the upper and lower body segments, divided at the symphysis pubis, is 1:1.7, with the upper segment being longer. By age 10 years the ratio is 1:1. Unusual skeletal proportions are characteristic of certain sexual aberrations that can exert an effect on dental development. Bone age is an indication of maturation and physical development of the skeleton and the dentition developmental stage. Wrist radiograms are

SCOPE Malocclusion is more than a biophysical morphologic deviation that requires the application of mechanical force only to bring about desired changes in the dentofacial area. Diagnosis in the individual patient entails the weighing of many variables which tend to modify each other and may even cancel out their respective etiologic significance. The correlation of chronologie age, skeletal age, and dental age is important for determining optimal time for planning and beginning treatment. The examination must be centered on the patient as a person and not merely on the malocclusion or on the dentofacial malformation alone. Above all it should not be based on the "system" of appliances used. The medical and dental history of the patient and the assessment of his growth are important in order to establish a diagnosis. The examination should be complete, but must at all times be practical. Only questions that have value in prescribing therapy should be asked. Mandibular Dynamics Examination. The clinical e aluation of mandibular dynamics should be made with the mandible in full occlusion and while it is going through its range of motions. The midline deviation should be observed with the teeth in full occlusion and at rest position in order to learn whether the mandible is shifted in going into terminal occlusion from rest position. This will indicate any discrepancy between centric jaw re-

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Suggestions for Diagnostic Examination Charts· 143 considered an adequate indicator of skeletal development. A disparity of 1 or even 2 years in bone age and chronologie age based on an accepted standard can (in the absence of other unfavorable systemic symptoms) be considered to be within normal range. Children with less than average skeletal development for their age may show well developed dental arches, while tall, well developed children may show deficiency of dentofacial development. Dental Age. The stage of dental development is determined by the order of appearance, the size, and the amount of calcification shown by the teeth, deciduous and permanent tooth eruption, and closure of the apices of the permanent teeth. The foregoing are compared with standard tables of normal dental growth and development. One estimate of dental age can be made from the number of teeth already erupted. A second, more limited •estimate, can be based on the age at time of calcification of the permanent mandibular first molars. A third estimate is based on the age at the time of completion of calcification of the dentition as a whole.

ORAL EXAMINATION In addition to charting dental defects and missing teeth, information should be obtained on the sequence of eruption, velocity of eruption, the time of shedding of deciduous teeth, and the presence of infection in the teeth and gums. The teeth should be examined in occlusion, when the jaws are opened, and when the mandible is in motion. Attention should be given to the appearance and texture of the oral mucosa and the alveolar and gingival tissues. A physical count of the teeth should be made to detect missing, supernumerary, over retained or prematurely lost teeth. A pulp-vi tali ty examination is of value before orthodontic appliances are placed on the teeth. Radiograms. Cephalometric radiograms help to obtain a quantitative analysis which aids in localizing the malocclusion. Cephalometric analysis shows the pattern of facial growth, arch length, and relative position of the dental arches, among other data, as found at the time the radiogram was obtained. Dental radiograms and casts can aid in obtaining information on the following: (1) the direction in which the teeth are to be moved, (2) changes required in axial position of teeth, (3) an analysis of overbite, overjet, openbite, crossbite, and the line of occlusion. The type of dental arch, whether tapering, round, or square, can be determined. Photographs. Photographs can show the face full

front and in profile, the soft tissues in repose, the habitual position of the head in space, and the changes brought about by growth and orthodontic therapy. Face Masks. Hydrocolloid or other plastics may be used to taking the impressions of the face when dramatic changes have been obtained. A method of making facial casts is as follows: 1. Place patient in a horizon tal position in the dental chair. 2. Cover the face, eyebrows, eyelashes, and hair about the temples and forehead with a thin film of petroleum jelly. 3. Adjust the heavy cardboard or metal face frame that will serve as a tray for the plaster. 4. Prepare a thin mixture of alginate. This is used to cover the face and is applied from the chin upward. Keep it away from the nostrils. Let the thin coating dry. 5. Straws in the nostrils or between the lips are not necessary, provided you are careful not to pour any loose alginate into the nostrils. To strengthen the alginate, a gauze covering may be incorporated into it before it is fully set. 6. Prepare a mixture of fast-setting plaster and pour it over the alginate, being careful not to occlude the openings at the nostrils. Pour plaster over the entire surface of the alginate to a thickness of about lh to V2 inch. 7. After the plaster has set, ask the patient to contract the muscles of the face, and then remove the alginate slowly. 8. Pour the impression in dental stone. The entire inside surface of the impression should be poured to the desired thickness of the cast to be made.

SUGGESTIONS FOR DIAGNOSTIC EXAMI A TION CHARTS The following can serve as suggestions of items that may be included in examination charts: 1. Name, sex, age at examination 2. Address 3. Parent responsible for patient 4. Medical History a. Parents and siblings b. Patient 1. Diseases of infancy and childhood 2. Operations involving dentofacial area 3. Accidents involving dentofacial area 4. Present state of health 5. Specify any current treatments 6. Malformations, hereditary and congenital

144 . Examination of the Patient 5. Dental History a. Age at eruption of deciduous teeth b. Age at beginning of eruption of perman~nt teeth c. Extractions d. Periodontal condition e. Oral hygiene f. History of traumatized teeth 6. Clinical Dentofacial Examination a. Facial musculature: normaL- hypotonic __ hypertonic __ b. Labial condition - competent- incompetent-; Upper lip: normal __ short __ functionaLnonfunctionaL-; Lower lip: functional __ nonfunctional __ 7. Congenital Defects a. Clefts, abnormal frenums b. Muscle abnormalities c. Tongue abnormalities 8.Functional impairment - difficulty in swallowing, chewing, jaw movements, tongue movements 9. Speech defects 10.Clinical Dental Examination number of teeth present __ missing __ carious __ . a. Teeth: carious extracted, nonvital, and filled. Caries susceptibility b. Mucous membranes: pale, pink, congested, swellings, ulcers, fistulas c. Periodontal condition: gingivitis hypertrophy, infections d. Oral hygiene: goo~ fair __ poor __ e. Quantity and quality of saliva f.Type and condition of previous dental work 11. Malocclusion a. Abnormalities of dental arches in form, size, and position: maxilla, mandible. Intermaxillary: curve of occlusion, overbite, openbite, dual bite b. Classification: Angle, skeletal

12. Abnormalities of teeth: size; shape: square, ovoid or tapering; hypoplasia or hyperplasia of enamel; grooved, mottled, color, stains, translucency; oligodontia; supernumerary teeth 13. Anomalies of dental development: state of eruption, root resorption, prolonged retention or premature loss of deciduous teeth, delay or eruption of permanent teeth 14. Anomalies of position of individual teeth: rotation, axial inclination, transversion (labial, buccal, lingual, mesial, distal, etc.) 15. Anomalies of groups of teeth: protrusion, retrusion, mesiodistal crowding, constructed dental arch, infraclusion, supraclusion, crossbite. 16. Habits interfering with proper dentofacial development: persistent thumb or finger sucking, nail biting, lip biting, tongue posture, tongue thrusting, orofacial pressure habits 17. Vitality test of the teeth as determined by their response to an electric pulp tester 18. Radiographic examination a. Intraoral 1. Individual dental radiograms 2. Bite-wing radiograms 3. Occlusal radiograms b. Extraoral and cephalometric radiograms 1. Lateral (profile) radiograms 2. Posteroanterior radiograms 3. 45° cephalometric radiograms 4.Temporomandibular articulation radiograms 19. Carpal or skeletal radiograms to obtain skeletal maturation rating 20. Dental impressions and casts 21. Photographic examination 22.Anteroposterior 23.Profile 24.Close-up of teeth, occlusion 25.Anomalies of individual teeth

12 Guidance of Occlusal Development SCOPE

Treatment of malocclusion while the dentition is undergoing active development can be corrected only to the given stage of development. When all permanent teeth have erupted, there may be a need for additional orthodontic treatment. Definitive orthodontic treatment must be postponed until all of the deciduous teeth in have been shed and the permanent teeth, with the exception of the third molars, are in the terminal stage of eruption. Treatment cannot be considered completed until jaw growth is completed. In some patients mandibular growth may not be completed until late adolescence or early adulthood. When this occurs the orthodontic result may show relapse and require retreatment. Etiology, classification of the malocclusion, and age of the patient are interdependent factors that determine time and type of treatment. A malocclusion at one developmental age level may be considered normal at some other level and vice versa. A form of treatment indicated at one stage of dentofacial development may be contraindicated at another. As long as malformation and malfunction continue, they contribute to making the malocclusion worse.

The scope of occlusal guidance includes the following' 1. Correction of anteroposterior or lateral malocclusions and malrelations of the dental arches 2. Prevention of space loss following premature loss of deciduous teeth and loss of permanent teeth 3. Extraction of overretained deciduous teeth 4.Recognition and treatment of habits that affect position, relation,' and function of the dentofacial components 5. Elimination of dental caries, especially those that cause the child to occlude the teeth off-centric in order to avoid pain and facilitate mastication 6. Extraction of supernumerary teeth that interfere with the establishment of normal occlusion Malocclusion can be intercepted in the incipient stage, especially when it is of local etiology. There are various interceptive measures that can guide the developing dentition into normal occlusion and forestall the need for extended orthodontic treatment.

TYPES OF ORTHODONTIC TREATMENT DENTOFACIAL ORTHOPEDICS

Forms of orthodontic treatment can be described as follows: 1. Preventive orthodontics 2. Interceptive orthodontics 3. Corrective - early and late 4. Posttreatment maintenance or retention 5. Dentofacial orthopedics

The correction of abnormalities and deviations from the normal range in the facial and oral tissues is the concern of dentofacial orthopedics. Classical orthodontic therapy is limited to the correction of alveolodental abnormalities that do not involve the bodies of the jaws themselves. Dentofacial orthopedics is an extension of orthodontics that includes the treatment changes in the jaws. Baume has reported changes in the mandibular growth vector following the application of pressure at the mandibular condyle. Examples of orthopedic measures in orthodontics include the following: 1. Palatal suture opening 2.Palatal expansion for widening the palate in cleft palate 3. The extraoral appliance for influencing the vector of growth of the maxilla and mandible

REEV ALUA TION OF TREATMENT PLANS Since the dentition of the child is in a dynamic st~te, and especially since the extent and quality of response to treatment varies among patients, treatment planning must be reevaluated from time to time and modified in accordance with the response of the patient to the treatment and not in relation to a preconceived "system" of appliance therapy. Diagnosis and treatment should not be applianceoriented.

145

146 . Guidance of Occlusal Development 4. The chin cap with cervical anchorage to reduce the forward extension of the mandible Types of malocclusion in order of decreasing frequency are: 1. Intramaxillary irregularity of tooth arrangement 2. Intermaxillary deviations of the dental arches with or without jaw abnormalities in size and shape 3. Abnormalities of jaw development 4.A combination of dental irregularities, lack of development, and malrelation of the jaws Irregularities of tooth position evidence themselves clinically in crowding, spacing, rotations, and proximal contact abnormalities. Irregularities may result from premature shedding or prolonged retention of deciduous teeth, the presence of supernumerary teeth, congenitally missing buds of teeth, and postnatal loss of teeth. In the deciduous dentition spacing is the most common problem; in the permanent dentition, crowding occurs most frequently.

THE AGE FACTOR IN TREATMENT OF MALOCCLUSION

Early Treatment Early treatment of gross malocclusions is conducive to better esthetic and functional results. Occlusal guidance without the use of mechanical appliances may be undertaken on patients of any age when indicated. However, care should be exercised to avoid interfering with inherent growth when using mechanical appliances during the mixed dentition period. Contra indications to early orthodontic treatment include the following: 1. Minor malocclusions in the deciduous dentition which may correct themselves by continuing dentofacial growth and development 2. Rampant caries and oral sepsis, which should be eliminated before orthodontic treatment is undertaken 3. Dentofacial conditions that primarily require surgery 4. A patient in a highly emotional state 5.Disturbances of general health that would interfere with continuity of orthodontic treatment

DIFFERENCES I RESPONSE TO TREATME T

The Ages of a Child The decision to initiate orthodontic therapy should be based on the presence of a condition that interferes with the continued normal development and function of the dentition of the child, regardless of age. A child has many ages - chronologie, skeletal, dental, physiologic, maturative or developmental, and mental-which mayor may not coincide with his chronologie age. Standards of growth and development do not apply precisely to the individual child.

Prevention Before Tooth Eruption Preventive measures can be instituted even before the teeth actually erupt into the mouth. Malocclusion can be initiated by improper selection of a feeding nipple for the bottle-fed baby and by improper position of both the infant and the bottle during feeding. A nipple long enough to rest on the anterior third of the tongue should be used, and small openings should be punctured in the sides of the bulb of the nipple instead of at the end only. This will prevent the infant from squirting the milk directly into the pharynx. With this type of nipple there is more spreading pressure on the jaws when the baby is nursing; this eliminates compression caused by sucking with the nipple held between the gum pads.

Differences in response to treatment can be caused by the following: 1. Timing of treatment. The best results are obtained during the active growth period, provided growth is favorable. 2. Bone resistance, the osteogenic quality of the alveolar process. The haversian systems tend to make bone anistropic, so that it is more responsive to force in some directions than in others. (For example, it is more responsive when teeth are moved in the direction that growth naturally proceeds.) 3. Failure to eliminate local and systemic etiologic factors that interfere with normal tooth arrangement or actually produce abnormalities Self-Correcting Malocclusion When the distinction is made between stages of growth and developing malocclusion, there are actually few instances of self-correction. Malocclusion may show change to normal occlusion or to different types of malocclusion during dentofacial growth and development. Examples of self-correction may be found in lingually erupting lateral incisors and in rotations of individual teeth which may show a delayed tooth eruption pattern, but which eventually find proper positions in the dental arches. Spontaneous correction of rotated teeth sometimes occurs while the roots are undergoing

Differences in Response to Treatment· 147 completion. Self-correction in mesiodistal arch relation can occur during the eruption of the permanent first molars and during the eruption of the premolars and permanent second molars. Self-correction has been observed in children with midline incisor diasternas on completion of the eruption of the permanent dentition. Self-correction can occur in protrusion of maxillary incisors when the incisors do not rest on the lower lip when the mandible is in rest position, or when the teeth are in full occlusion. When the maxillary incisors are displaced forward and the lower lip falls lingual to the maxillary incisors: it continues their forward displacement. Incisor malocclusion usually corrects spontaneously if thumb- or finger sucking is discontinued by age 4 to 6 years, provided inherent growth is favorable; that is, if: (1) the lower lip does not rest lingual to the maxillary incisor teeth, (2) the tongue does not habitually lie in the interarch space over the occlusal and incisal surfaces of the teeth, and (3) there are no other developmental defects or interferences with dental occlusion.

fied as malocclusion at the transition from the deciduous to the permanent dentition may, in fact, be phases of normal growth. For example, deep overbite in the deciduous dentition at 3 or 4 years may

Transitional Malocclusion Conditions in the child patient that can be classi-

A

D

6VRS.5 MO.

10YRS.O MO.

Fig. 12-1. The casts on the left, made at the age of 6 years and 6 months, show a stage of dental development that may be mistaken for an openbite condition. Casts on left at 8 years of age show elimination of openbite as teeth continued to erupt. The child's dentition, beginning with the eruption of the permanent teeth, is in a highly dynamic state. Development and growth changes in relation to age are important factors in the diagnosis of malocclusal tendencies.

B

E

8VRS.1 MO.

11YRS. 0

M

c

F

9YRS.

0 MO.

12vRS.OMU

o, ages show the change in inclination of the incisors and Fig. 12-2. Posteroanterior roentgenograms of a child at successive the path of eruption of the maxillary canines. Failure of the canines to change their eruption path results in their impaction. (B. Holly Broadbent)

148 . Guidance of Occlusal Development disappear as the mandible is rotated forward during growth. Teeth coming into occlusion, especially in the incisor region, may appear to be, and frequently are, in malocclusion. Such cases should receive periodic reexaminations to ascertain whether these teeth are actually in malocclusion. Serial clinical examinations are especially valuable during the transitional dentition period, when the deciduous teeth may be abnormally resorbed, prematurely lost, or over-retained.

The Vestibular Screen When the lower lip rests lingual to the maxillary incisors they are propelled into increasing protrusion. This can be alleviated with a vestibular screen. The screen is a sheet of plastic adapted to fit over the teeth that makes it impossible to bite the lip or place it lingual to the maxillary incisors. The screen can be used to keep the tongue from producing open bite by resting over the maxillary and the mandibular dental arches. It can be used also to reduce maxillary incisor abnormal overjet. The screen makes it impossible for the child to introduce the fingers or thumb into the mouth and suck them. The screen should be worn as much as possible. It should be placed in the mouth at least 1 hour before bedtime; otherwise, it will annoy the child and keep him awake. The vestibular screen is constructed as follows: 1. Maxillary and mandibular impressions that extend to the mucobuccal folds are taken. 2. Stone casts are poured.

3. The mandibular cast is elevated to approximate normal occlusion with the maxillary incisors. 4. An acrylic sheet is trimmed clear of the maxillary and the mandibular mucobuccal folds and frenums and extended to the distal surface of the second deciduous or permanent first molars. 5. The screen is bent slightly away from the buccal dental segments so that it rests on the protruding anterior teeth. If the screen is to be used for lip exercises, a wire ring is inserted on the labial surface at the level of the edge of the upper lip. 7. The screen is trimmed and polished. 8.The patient is instructed to place the appliance in the mouth as long as possible before going to bed. Usually by the third night the screen can be worn comfortably. The screen may be used during active treatment with appliances in the mouth and during retention. A lip bumper may be used as a means of avoiding extraction in so-called borderline cases. The lip bumper is inserted prior to loss of the deciduous mandibular second molars. Thus the leeway space is maintained, and the actual distal movement of the permanent first molars provides sufficient space for regular alignment of the anterior teeth and mandibular dental arch. Headgear therapy may be used on the maxillary permanent molars in conjunction with the lip bumper.

SPACE MAINTAINERS Space loss after a deciduous molar is exfoliated is more marked in the maxillary than in the man-

Fig. 12-3. (Top, left) Completed vestibular screen. (Top, right) Vestibular screen in position. (Bottom)

Method of using vestibular screen for exercising the orbicularis oris muscle.

Prevention of Dental Arch Collapse· 149 dibular dental arch. Space closure is greater after loss of a deciduous second molar than after loss of other deciduous teeth. A space maintainer is a passive and frequently an active orthodontic appliance. Space maintenance, if not properly applied, can interfere with the time scale of occlusal adjustment in the mixed dentition. The space maintainer should receive inspection and adjustment at frequent intervals and should be removed when no longer needed to avoid interference with the succeeding erupting permanent tooth and the establishment of normal permanent occlusion. Indications The following can serve as a guide for the use of space maintainers: 1. When the space shows signs of closing as determined by actual measurement of the space required for the succeeding permanent tooth. 2. If retention of the space will make eventual treatment of malocclusion when necessary less involved. The following conditions should be met by a space maintainer: 1. It should maintain the desired mesiodistal dimension of the space. 2. It should not interfere with the eruption of the occluding teeth. 3. It should not interfere with speech, mastication, or functional movement of the mandible. 4. It should not interfere with the eruption of the permanent teeth. 5. It should provide sufficient mesiodistal space opening for the normal alignment of the permanent teeth. Space maintainers are contraindicated under the following conditions: 1. When there is no alveolar bone overlying the crown of the erupting tooth and the space is sufficient to permit its eruption. 2. When the space left by the lost deciduous tooth is in excess of the mesiodistal dimension of its permanent successor, as "Shown by measurement on the radiogram, and where repeated examinations show that the space is not closing. 3. When retention of the space is contraindicated because of a general lack of sufficient dental arch length, requiring eventual extractions, and where space maintenance would further complicate existing malocclusion. 4. When the permanent succeeding tooth is absent and it is necessary to close the space by orthodontic treatment.

Fig. 12-4. Construction of the vestibular screen. (Top, left) Casts show protrusion of the maxillary central and lateral incisors. (Top, right) Same casts with the mandibular cast raised to approximate the maxillary incisors prior to the construction of the vestibular screen. (Center, left) Vestibular screen constructed of acrylic or plexiglass with wire handle inserted. (Center, right) Vestibular screen in position with casts approximated in proper relationship. (Bottom, left) Occlusal view showing the vestibular screen fitted to rest on the incisor teeth. (Bottom, right) Anterior view of vestibular screen with wire prongs inserted to overcome tongue thrusting and resultant openbite. PREVENTION OF DENTAL ARCH COLLAPSE Decrease in mandibular arch length can be avoided by using a stabilizing lingual arch appliance when the deciduous molars and the premolars that replace them show comparatively little difference in mesiodistal diameter, or "leeway" space. The stabilizing arch is removed when the greatest diameters of the crowns of the premolars and

150 . Guidance of Occlusal Development Fig. 12-5. (A) Space maintainer, consisting of a band on permanent first molar and a wire running along the mucosa and on the distal aspect of the first premolar. (B) Space maintainer with adjusta ble loop, which permits beginning of eruption of second premolar without interference of the space maintainer. (C) Side view of B. (0) This lingual appliance is used to prevent collapse of the dental arch and tooth shifting following loss of deciduous molars. (E) Cast for which the appliance was made.

permanent canines have erupted through the alveolar mucosa. When an excess of interdental spacing is present, the removal of the stabilizing lingual arch permits the mandibular first molars to shift forward and close the spaces. Stabilizing lingual arch construction 1. Bands with vertical half-round tubes soldered lingually are fitted to the permanent molars. 2. The lingual arch is bent to lie in contact with the linguogingival margins of the mandibular teeth and the gingivae of the mandibular incisors. 3. Vertical half-round posts are fitted on the lingual archwire to fit into half-round tubes attached to the molar bands. The lingual arch may be soldered directly to the molar bands when so desired. The lateral segments of the arch should be adjusted so that they do not interfere with the erupting permanent teeth. TREATMENT OF LABIAL FRENUMS

3 .. Abnormal eruption of central incisors 4. Supernumerary teeth' 5. Oligodontia, especially agenesis of permanent lateral incisors 6. Tooth shifting following loss of teeth 7. Genetic factors Separation of the central incisor teeth may not, and frequently does not, have any relationship to a large frenum. Separation between the central incisors can persist after frenum excision under the following conditions: 1. When the ligament connecting the frenum with the incisor papilla lies in an opening in the alveolar bone. 2. When the alveolar bone between the incisors is a square single mass of bone. When an excessive amount of bone is present between the central incisors, the excision of the frenum has no effect on the space. The foregoing anomalies require active orthodontic tooth movement to approximate the central incisors. This usually causes the frenum to recede. The teeth should be retained in approximation until the canines have erupted.

Separated Maxillary Central Incisors Separation of the maxillary central incisors during childhood is a normal occurrence in dental eruption. Practically all maxillary permanent central incisor teeth erupt spaced at some distance from one another but eventually come together. Angle advised excision of the frenum. Mershon pointed out the dangers of unnecessary surgical excision of frenums. Abnormal midline frenums may have a wide base or they may be thin and fibrous. Both types can be responsible for spacing. The following conditions may be found with abnormally spaced maxillary central incisors: 1. Abnormal maxillary midline frenum 2. Presence of peg-shaped lateral incisors

Periodontal Treatment in Malocclusion Poor arch relationship with dental irregularities can result in gingival and periodontal trauma. Periodontal disturbances in children are usually caused by diabetes, allergy, endocrine and digestive disturbances, disorders of circulation and avitaminosis. Although prevalence and severity of periodontal disease increase with age, the onset of destructive lesions occurs early in life. Young girls are more severely affected than boys. In later years men show more periodontal disease than women.

Treatment of Labial Frenums' 151

B

A Fig. 12-6A. (Top left) Stabilizing lingual arch to reenforce anchorage. Note. This arch can be used also to maintain dental arch length after premature loss of deciduous teeth. B. (Top, right) Lip-plumper appliance with contoured plastic vestibular portion and closed coil spring stop. e. (Bottom, right) Intraoral view of lip plumper in position. First permanent molars banded with combination tubes, 0.018 by 0.025 inch, and 0.045 inch round tubes. Tubes positioned parallel to occlusal plane. Lip plumper adjusted 2 to 3 mm. labial to lower anterior teeth and 2 to 3 mm. above depth of vestibule.

Fig. 12-6D. Case 1. Pretreatment view. ote incisor crowding and right canine .nalposition, (Courtesy Faustin Weber)

Fig. 12-6E. Posttreatment view. Note improvement in alignment and arch form. Lipplumper treatment only used in lower arch. (Courtesy Faustin Weber)

152 . Guidance of Occlusal Development

A

B

c

76.

o

Fig. 12-7. Various lypes of bone formation in abnormal frenum labii. (A) man, 44 years of age; (B) girl, 9.7 years of age; (C) man, 50 years of age, permanent separation; (D) woman, 44 years of age, permanent separation. (After H. Chapman.)

Fig. 12-8. (Top) Maxillary permanent central incisor teeth are widely spaced and root formation is just beginning. (Bottom) Mandibular permanent incisor teeth show advanced eruption with root formation just beginning. Moving teeth with roots in the early stages of calcification leads to root distortion.

Fig. 12-9. (Left) Diastema in an adult who has no lateral incisors. (Right) The teeth show evidence of traumatic occlusion in the widened periodontal space and occlusal grinding to overcome trauma, since there was an edge-toedge occlusion.

Orthodontic tooth movement in some children, especially where mouth hygiene is poor, may show thickening of the gingival mucosa. Proper mouth hygiene and massage with a water pulsating device will return the gingival tissues to normal in the absence of other etiologic factors. Extremely light force should be used when moving

periodontally involved teeth. The periodontally affected permanent tooth, when moved into a new and more favorable location and then sufficiently stabilized, will frequently become firmer than before it underwent tooth movement. Periodontal treatment may be carried on simultaneously with orthodon tic therapy.

Treatment of Labial Frenums' 153 Fig. 12-10. (Top left) An abnormal frenum caused a wide diastema between the central incisors. With the eruption of the lateral incisors (which are undersized) the diastema almost (right). When the closed permanent canines erupt the diastema may close entirely without orthodontic therapy. In this case, retention will be continued until the permanent canines have erupted. (Bottom) Radiograms before (left) and after (right) eruption of the permanent lateral incisor teeth. Retention will be continued until the permanent canines are erupted.

Fig. 12-11. Thumbsucking caused openbite and diastema between the maxillary central incisors. The space was closed by orthodontic therapy. Note the closure of the midline suture in the alveolar bone.

154 . Guidance of Occlusal Development

77. DENTAL ARCH AND JAW DISCREPA CIES Basal Arch Discrepancy The basal arches are the areas at the most constricted part of the body of the maxilla and the mandible. Basal arch discrepancies in relation to dental arch space requirements for normal tooth arrangement can be unimaxillary or bimaxillary. As a result of basal arch discrepancies there may be crowding, impaction, and procumbency of the incisor teeth.

Large Basal Arches When the maxillary or mandibular basal arch is too large in relation to the mesiodistal space required by the dental arch, spacing and diasternas can occur. The arrangement of the teeth in the dental arches then will depend primarily on muscular pressure, tongue size, jaw relationship and function, and dentofacial pressure habits. When treating spaced teeth in the presence of a large basal arch, the dental arch should not be constricted. Spaces should be closed by moving the teeth along the same arc described by the spaced dental arch.

Constricted Basal Arches

Fig. 12-12. (A) The central incisors are still separated in this adult whose frenum labii was cut in childhood. (B) Incisors are crowded in an adult whose median maxillary frenum was completely excised in childhood.

If the basal arch is constricted or too small in relation to the coronal arch, the mandibular incisors and other teeth will be crowded out of normal alignment. If there is normal dental arch alignment, the incisors will show a procumbent relationship to a plane tangent to the base of the mandible. Arch length deficiency may not be responsible for tooth crowding in Class I malocclusion when the entire dentition is in a forward position in relation to the body of the jaws themselves.

Fig. 12-13. Front and side views of casts showing areas covered by the basal arches.

78.

Abnormal Overbite' 155

Fig. 12-14. (Top) Edge-to-edge occlusion before and after treatment. (Second row) A removable appliance with a top flange was used in treatment. (Third row) A mandibular removable appliance with an anterior flange was used in a 12-year-old girl who had a tendency to relapse into Class III (Angle) malocclusion after termination of treatment for that condition. (Right) With the appliance in position, the maxillary and mandibular arches are slightly separated and the maxillary incisors are allowed to become elongated to increase the overbite,. (Bottom) The lateral view of the appliance on the cast shows the anterior portion trimmed away from the lingual surfaces of the mandibular incisors. (Right) View of appliance from below, caused by lack of growth at the tuberosity of the maxilla or at the inner angle of the ramus and body of the mandible. Crowding in the molar region may occur independently or in conjunction with crowding or procumbency of the incisor and other teeth in the mandible and in the maxilla.

ABNORMAL OVERBITE Crowding of Teeth and Basal Arch Size While the size, form, and relationship of the jaws are independent of the size of the teeth, tooth arrangement is greatly dependent on the size of the jaws and on the relationship of the jaws to each other. Therefore, teeth moved into apparently normal arraqgement by orthodontic means will not stay in position when the basal arches of the jaws are too small to permit such teeth to occupy the new locations, since they are thus in conflict wi th the intrinsic lines of functional stress of the jaws. Extraction then becomes a necessary adjunct to the orthodontic therapy. Crowding of the molars, especially the second and the third molars, can be found in arch inadequacy

Overbite refers to the vertical relationship of the maxillary to the mandibular incisors. Normal overbite usually occurs when the sequence of eruption is canine, first premolar, second premolar in the mandibular arch and first premolar, canine, second premolar in the maxillary arch. Incisor overbite develops independently of molar height. Variations in the degree of overbite in normal occlusion can be attributed primarily to the axial position of the incisor teeth; vertical position of the maxillary incisors encourages deep overbite, alveolar growth and mandibular incisor height. Abnormal overbite may be inherited. It is present when the incisor overlap extends vertically more than one third over the opposing tooth crowns. In the mixed and permanent dentitions overbite de-

156 . Guidance of Occlusal Development

Fig. 12-15. (Top row) A removable appliance for bite opening seen from the tissue surface (left), the lingual surface (center), and in place in the maxillary dental arch (right). (Second row) Pretreatment casts (lefl) and the teeth after treatment (right). (Third row) The appliance with a labial wire to aid retention: (leit) in place in the mouth and (right) from the lingual aspect. (Fourth and fifth rows) Comparison casts of a case of persistent open bite. Lateral, anterior, and occlusal views of two sets of casts. In each set, these on the left were made at age 4 and those on the right, at age 15.

Open bite . 157

Fig. 12-16. (A). Casts of open bite in a woman caused by tongue posture over the incisor and lateral series of teeth. (B) The casts of a different patient, show overjet and overbite.

pends primarily on the extent of mandibular forward growth during the eruption of the mandibular permanent incisor teeth and on the axial relation of the incisors. Abnormal overbite is most prevalent in the mixed dentition. Openbite is comparatively more prevalent in the deciduous and early mixed dentition and tends todisappear in the later mixed dentition period. After the eruption of the permanent canines and premolars the overbite in the permanent dentition is established. Molar eruption is not the determining factor in severity of overbite.

ABNORMAL OVERJET Overjet refers to the horizontal protrusion of the maxillary incisors in relation to the mandibular incisors. Abnormal overjet can be caused by (1) anterior maxillary alveolar overgrowth and incisor pro-

trusion, (2) forward overdeveloprnent of the maxilla, (3) a retrognathic or undersized mandible, (4) difference in the amount of alveolar prognathism in the respective jaws, (5) the presence of abnormal labial inclination of the maxillary incisors, (6) pressure of a large tongue, and (7) lip biting, finger sucking, and other orodental pressure habits.

Extraction in Abnormal Overjet or Overbite Abnormal overjet and overbite are not contraindications to extraction. Tooth extraction in orthodontic treatment is not a reason for increase in overbite or openbite. Errors in orthodontic therapy can cause these conditions. OPEN BITE Openbite is the failure of the occluding surfaces of the teeth to achieve contact when the teeth are

158 . Guidance of Occlusal Development Fig. 12-17. This adult's openbite was caused by lower lip sucking and posture -of the tongue over the incisal surfaces of the mandibular incisors. The occlusion in the lateral jaw segments is not disturbed. The habit produced spacing and protrusion of the maxillary incisors and canines.

Fig. 12-18. Plumper used to overcome lip sucking habit.

brought into full closure. The cause of open bite, in the absence of gross jaw bone deformities, is interposition between the dental arches of the tongue, the lip, the fingers, or other objects for periods of sufficient duration, and frequency generating sufficient force to interfere with the establishment of normal occlusion or to affect the alveolar bone and move the teeth out of occlusion. Tongue posture over the occlusal and incisal edges of the teeth is a causative factor of open bite. In total openbite, the tongue may overlie the occlusal surfaces so that the premolars and molars are prevented from achieving full occlusion without overclosure of the mandible. Incomplete eruption and alveolar deficiency are results of open bite, not causes, except in arrested eruption of ankylosed permanent teeth. There is no evidence that posterior supraclusion, an obtuse

mandibular angle, a short ramus, or downward bending of the mandible at the antegonial notch can cause openbite. Patients with short rami, obtuse gonion angles, and short mandibles without tongue posture over the occlusal surfaces, do not show openbite. They do show extremely long anterior mandibular height from infradentale to menton. Treatment should be directed primarily to eliminating the causative factors. The curve of occlusion of the mandibular teeth should be corrected, and the maxillary teeth should be brought into vertical alignment. The use of an activator appliance 12 to 14 hours per day will tend to close the openbite because the tongue cannot rest over the incisal edges of the teeth. A plumper appliance keeps the lower lip from being held on the occlusal surfaces of the teeth. When orthodontic appliances are used

Tongue Thrusting· 159 Fig. 12-19. Front view showing extremely long distance from gnathion to incision.

Note. Openbite in the absence of tooth ankylosis is caused by an object which intervenes between the teeth. Otherwise, the teeth seek antagonists and continue to erupt with or without elongation of the alveolar process. The obtuseness of the gonial angle is not a factor in openbite.

vertical elastics are employed to close the open bite and keep the lower lip from resting on the incisal edges of the mandibular teeth.

79. 80.

TONGUE THRUSTING Tongue thrusting and the deficient function of the upper lip and of the hyoid suspensory musculature are indications of possible lack of neuromuscular maturation and may be etiologically related to the other muscle and neurogenic problems. Examination and treatment of tongue thrusting should include the following: 1. The posterior pharyngeal wall, fauces, and soft

Occlusal rest, upper first premolars

Fence construction, no interference, all excursions of mandible

Palatal bar clears anterior teeth

Occlusal rests, upper first premolars

Platform clears palate

Hayrake clears upper and lower anterior teeth

Fig. 12-20. (Left) The palatal bar acts as a habit reminder by breaking the seal that would otherwise create suction. (Right) The hayrake is a mechanical device with a "fence" that interferes with the pleasure of thumb-sucking. (Klein, E. T.: Am. J. Orthodont., 59:286, 1971.

160 . Guidance of Occlusal Development

Fig. 12-21. (Top) A large tongue and a forward tongue posture resulted in openbite and crossbite. (Bottom) A lingual appliance with maxillary springs was used to widen the maxillary arch to correct crossbite. A grid was attached to the appliance to confine the tongue. palate should be examined to rule out neurogenic functional interferences. 2. Intrinsic and extrinsic tongue muscle action should be checked. 3. Position of the mandible when swallowing

should be checked to determine presence of lateral occlusal deviations. 4. The presence of grimacing during swallowing is usually an indication of tongue thrusting. 5. A blunt instrument should be used to show the patient and parent where the tip of the tongue should press when swallowing. 6. The patient should be told to put the tip of the tongue at the junction at the gingivolingual aspect of the maxillary incisor teeth, to pronounce the word lay, and to repeat that sound until he realizes that the tongue contacts the area where it should be during the act of swallowing. Some openbite swallowers will produce the lay sound with the tongue farther back on the palate or against the mandibular incisor teeth. The patient's attention is directed to observe that the lay sound is produced at the linguogingival margin of the maxillary incisors. 7. When the patient knows where to place the tongue, he is told to bring the teeth into full occlusion, press hard with the tip of the tongue, and swallow. After a series of exercises, this pattern of swallowing becomes habitual and involuntary. 8. The patient may be asked to bring the teeth into full occlusion and flatten the tongue to reach the lingual surfaces of his premolars and molars, as in pronouncing k, and to swallow keeping the teeth and tongue as indicated. The swallowing exercise should be practiced by the patient at least 25 times before each meal. Lingual alveolar speech sounds in such words as lady, today, tonight, or the k sound should be practiced. For psychologic reasons it is best not to magnify

Fig. 12-22. (Top) Habitual lip- and tongue biting created this openbite. The patient thrust the tongue under the lingual appliance that was fitted to correct the habit (right). (Bottom) An appliance was then constructed on the mandibular arch that successfully confined the tongue. When the patient continued to bite the lip, a plumper was constructed to help overcome that habit.

The Split-Plate Appliancr . 161 the tongue thrusting habit in the mind of the child patient but to seek cooperation from the patient and the mother in practicing the swallowing exercise. The correction of incisor malocclusion frequently eliminates the tongue thrusting. Activator appliances that confine the tongue are helpful in correcting tongue thrust. The rake appliance affixed to molar bands on a palatal or lingual arch also may be used. Regardless of the appliance used, the habitual tongue thruster who does not cooperate will manage to bring the tongue past the obstruction placed in its path, and the tongue thrusting will persist. 'An appliance is made of a 0.030-inch round archwire attached to the upper first molar bands with an anterior platform which clears the palate by about Vs inch. This keeps the thumb or finger from exerting pressure on the soft tissue of the palate. An occlusal rest on the occlusal surface of the upper first premolars prevents the palatal bar from settling into the soft tissue. The seal is broken, and the pleasure of thumb sucking is destroyed. The bar must be so designed that it will not prevent the teeth from closing normally.

THE SPLIT-PLATE APPLIANCE The use of expansion plates was mentioned by Robin in 1902 and Badcock in 1911, and now many types are used. The average distance per quarter turn of the expansion screw expands the plate from 0.18 to 0.1 mm. Activation should not exceed one turn a week. It is inadvisable to turn the screw only because the sensation of tension on the teeth is not Fig. 12-24. This tongue-thrusting patient was treated for Class II, Division 1 malocclusion, and was 3 years out of retention when the photographs were taken. Note that satisfactory occlusion has been maintained in spite of tongue thrusting. Tongue posture and lip sucking, rather than tongue thrusting, are etiologic factors in anterior open bite. .

Fig. 12-23. These photographs show tongue thrusting, interdental tongue posture, and open bite in a mother and her son. Tongue thrusting, jaw posturing, and occlusal mannerisms have been found to show genetic reference. (Salzmann, J. A.: Am. J. Orthodont., 61:466,1972)

felt by the patient. Expansion screws with springs have not been shown to have any advantage over rigid expansion screws.

162 . Guidance of Occlusal Development

81.

Fig. 12-25. (A, lop). Casts of patient who showed that the right mandibular lateral incisor had been extracted. Note abnormal overbite and cusp-to-cusp occlusion on the right side where the lateral incisor was extracted. (Bottom) Occlusion after treatment. Normal intercuspation and opened anterior overbite. (B, lefl) Occlusion before treatment. (Right) Occlusion after treatment. Note. The right permanent cani.ne was moved forward to serve in place of the extracted lateral incisor.

Orthodontic expansion screws should have high mechanical efficiency, minimal bulk, and a transverse dimension of at least 4 mm. The HawleyRussell 999 screw is recommended where 4 mm. or less widening or expansion is required. For distances exceeding 4 mm, the Hawley-Russell 666 screw is recommended.

THE HAWLEY RETAINER Biteplanes used for tooth movement produce tipping. Sometimes the root will tend to follow the crown, but this usually takes a long time. In some

instances by moving the crown of one tooth against that of the adjacent tooth and by applying spring force gingivally. the tooth can be moved to a more vertical position. Gore successfully closes extraction spaces by this method with the Crozat appliance. Control of the axial inclination of teeth is an important consideration when moving them by means of biteplates. When incisors protrude and there is no need to change the position of their roots, the biteplate and other removable appliances can be used with a flat plane, opening the bite sufficiently to free interlocking of the cusps (3fs-inch). Wire springs attached to plates should be cut to size when

The Higley Stabilizing Plate' 163 the appliances are fitted in the mouth. The ends of the wire can then be rounded by adding a drop of solder or by turning the end of the spring on itself. Springs should be activated so that the appliance is opened or closed by a distance somewhat less than the width of the tooth to be moved. If the appliance is to be used for closing spaces in extraction cases, impressions should be taken and the appliance constructed before the extractions are made. Distal movement of premolars can best be obtained by freeing the occlusal surfaces and by opening the bite so that the maxillary and mandibular teeth are not brought into actual contact. Distal movement of molars can be performed with finger springs attached to a plate. Space closure in the mandible is not easily accomplished with a removable appliance when there is need for bodily movement of the mandibular incisors. Using biteplates for tooth movement seems easy. While it is easily accomplished, retention is important, as is control of axial position of the teeth. Removable appliances require exact knowledge of appliance manipulation as do the fixed appliances. The use of a biteplate to correct excessive overbite frequently fails when the correction of excessive overbite requires changes in the axial relations of the maxillary to the mandibular incisors. This cannot easily be accomplished with biteplates. Biteplates make it possible for the posterior teeth to elongate by continuing eruption and alveolar process elongation. Whether they will relapse to their former height after the plate is removed is uncertain. If the masticatory muscles, especially the strong masseter muscle, are stretched when the posterior teeth are elongated, there will be a tendency for the vertical dimension to return to its original size. The intrusion of mandibular incisors into the alveolar process will not remain when the plate is removed if the mandibular incisor teeth do not have proper contact and angular relation with the maxillary incisor teeth. The maxillarymandibular incisor angle should not be allowed to remain excessively obtuse in deep overbite. If a biteplane (like. the Oliver guideplane) or a Hawley retainer is used, the inclined plane should be constructed in the mouth of quick-setting acrylic. The retainer should then be removed. When the quick-setting acrylic is hardened, it is trimmed so that the mandibular incisor teeth fit directly against the inclined plane. Among the changes that can be effected by means of biteplanes are the following: 1. Forward positioning of the head of the mandibular condyle repositioning the mandible especially in growing young children

2. Opening of the bite, diminishing the overjet of the anterior teeth 3. Elevation of the posterior teeth; the anterior teeth may be slightly depressed or both changes may occur 4. A more normal anteroposterior relationship of the occlusion 5. Retention after correction of distoclusion 6. With myofunctional therapy 7.Relieve locking of individual teeth or groups of teeth 8. To eliminate tongue habits, lip biting, thumbsucking and other deleterious habits Note. In Class II, Division 2 (Angle) malocclusion the interference of the anterior and other teeth should be removed before the biteplane is used. Biteplanes should not be used where there is a tendency toward an openbite. 9. To retain space in premature loss of teeth 10.With additional spring attachments, to move groups and individual teeth 11. In correcting the mesial position of the mandibular teeth in the deciduous dentition Increase in face height following the use of biteplanes due to vertical increase in the posterior dental region, mostly in the maxillary posterior teeth. Increase in vertical dimension is accompanied by change also in the mandibular position.

THE HIGLEY STABILIZING PLATE A stabilizing plate can be used as a means for obtaining anchorage in orthodontic tooth movement. An acrylic plate, similar to a Hawley retainer, is made for either the maxilla or mandible, as required in treatment. The plate, devised by Higley and Moyers, is constructed so that it lies in lingual contact with the teeth and covers as much of the soft tissues lingually as possible. The plate is supplied with wire extensions to which are soldered vertical round or half-round shafts that insert into lingual half-round tubes soldered to the molar bands. These help to hold the plate in position. The stabilizing plate makes it possible to move the canines and the incisors distally without also moving the posterior teeth mesially in extraction cases. The plate may be cut away from the lingual surfaces of the incisor teeth which may then be moved distally by means of intramaxillary elastics attached to wire extensions on the plate distal to the canine proximal contact points. When reciprocal movement of posterior teeth mesially and anterior teeth distally and lingually is desired the plate is removed and intramaxillary elastics are used.

164 . Guidance of Occlusal Development Construction of Stabilizing Plate 1. Construct the molar bands taking care to solder the lingual half-round tubes perpendicularly. Solder intermaxillary hooks on the buccal surfaces. 2. Take an impression with the uncemented bands in place on the teeth. 3. Remove molar bands from the teeth and seat them in their proper position in the impression. 4. Pour the impression in stone. 5.Construct a wire framework. Process in quicksetting acrylic; a broad contact of acrylic with the teeth is desirable. It is advisable to cover the lingual surface of the molar bands or overlay them with a layer of heavy tinfoil before processing. This facilitates the removal of the band from the acrylic. 6. Remove the molar bands from the plate and cement them in place on the teeth. 7. Polish the plate and insert in the mouth after bands are cemented.

THE CHINCAP The chincap was used by Cellier (1802) and by Fox early in the 19th century. Tomes described it in 1873; Victor Hugo Jackson (1890) used it. Angle, Case, and Oppenheim and other used the chincap early in this century. The chincap can inhibit forward translatory growth of the mandible. Maxillary growth can then be expected to overcome the disproportion in forward growth. The chincap should not be used in an attempt to retract the mandible; its purpose is to exert a holding effect. It should fit snugly but should not exert appreciable pressure. It is of value primarily during the active growth period in the young child. Changes produced by the chincap can be compared to the skull changes brought about by certain South American Indians who flattened the heads of children, producing cranial deformities. The changes produced occur in the vector of growth but not as a result of inhibition of growth. Gentle pressure on the chincap should be directed in a backward rather' than an upward direction. Pressure against the temporomandibular articulation should not be directed for the purpose of inducing changes in the glenoid fossa. Armstrong found that young children with Class III dental incisor relation show an appreciable improvement when the chincap is used. It inclines the incisors lingually. The chincap should be worn 12 to 14 hours a day. Oppenheim was the first to use force to move maxillary teeth mesially by means of extensions from a chincap to which intermaxillary elastics are attached.

CONSTRUCTION OF ACRYLIC RETAINERS 1. Form the wire attachment according to the type of appliance required. Remove the attachment before painting the cast with acrylic separating medium. 2. Carefully replace the wire attachment in its proper position and apply acrylic powder and liquid. If necessary, the wire may be held temporarily in position with sticky wax or other material added on the buccal and the labial surfaces not to be covered by acrylic. 3. Build the palate by alternately applying the acrylic powder and liquid. Work only on relatively small areas, in order to maintain better control overall. Begin construction of the palate by distributing a layer of acrylic powder with the dispensing bottle. Spread powder uniformly. 4. Saturate the powder with acrylic liquid from the dropper bottle. Use liquid generously; too much does no harm, and too little may result in an unsatisfactory bond. Build the area to the desired thickness by repeating the process. 5. The center of the palate is built last because excess lateral material tends to gravitate toward the center. 6. Turn the cast down on its occlusal surface and permit it to remain in this position for about 15 seconds. This prevents soft material from drifting into the center of the palate. 7. When the material is tacky turn the cast over and smooth out rough spots with a finger. If the acrylic has set too fast, soften it by adding a few drops of liquid and smooth it over. 8. Allow the appliance to cure on the cast at room temperature for 30 to 45 minutes. This prevents warping and shrinking. The acrylic plate may be lifted out of the cast with a knife or any other sharp instrument. 9. Trim and smooth the excess material from the interdental spaces with burs and disks. For the best result, soak the appliance in water overnight to further cure the material and eliminate unpleasant taste.

REPAIRING RETAINERS 1. Place the retainer on original cast or construct an index so that the retainer lies passive. 2. Clean, trim, and smooth the irregular edges along the break with a bur or stone. 3. Acrylic separating medium is applied on the palatal area of the cast and the broken parts are replaced on the cast. From this point on, the standard procedure is followed by adding quick-setting

Bibliography· 165 acrylic until the break is completely filled. When the acrylic is set the retainer is trimmed and polished.

BIBLIOGRAPHY Alldritt, S.: Gingivitis and imbrication. D. Practitioner, 22: 60, 1972. Andersen, W. S.: The relationship of the tongue-thrust syndrome to maturation and other factors. Am. J. Orthodontics, 19:264, 1963. Anderson, D. L., Thompson, G. W., and Popovich, F.: Relation of socioeconomic level to sucking habit and tooth eruption. Program and Abstracts of Papers, Fiftieth G;eneral Session, IADR, March 1972. Ast, D. B., Allaway, ., and Draker, H. L.: The prevalence of malocclusion related to dental caries and loss of first permanent molars in a flouridated city and a fluoridedeficient city. Am. J. Orthodontics, 48:106, 1962. Backlund, E.: Facial growth, and the significance of oral habits, mouthbreathing and soft tissues in malocclusion. A study on children around the age of 10. Acta odont. scandinav.,21 [Supp.]: 36, 1963. Ballard, C F., and Bond, E. K.: Clinical observations on the correlation between variations of jaw form and variations of oro-facial behaviour, including those for articulation. Speech Path. & Therapy, 3:55, 1960. Benjamin, L. S.: Non-nutritive sucking (thumbsucking) and dental malocclusion in the deciduous and permanent teeth of the rhesus monkey. Child Dev., 33:29, 1962. Beresford, J. S.: Orthodontic Diagnosis. Bristol, England, John White & Sons, Ltd., 1965. Bhaskar, S. ., et al.: Water jet devices in dental practice. J. Periodcnt., 42:658, 1971. Bishara, S. E.: Management of diastemas in orthodontics. Am. J. Orthodontics, 61:55, 1972. Bowden, B. D.: A longitudinal study of the effects of digit- and dummy-sucking. Am. J. Orthodontics, 52: 887, 1966. Chandler, T. H.: Thumbsucking in childhood as a cause of subsequent irregularity of the teeth. Boston Med. & Surg. J., 99:204, 1878. Clinch, L. M., and Healy, M. J. R.: A longitudinal study of the results of premature extraction of deciduous teeth between 34 and 13-14 years of age. Tr. Brit. Soc. Study Orthodont, p. 109, 1958. Clinch, L. M.: A longitudinal study of the results of premature extraction of deciduous teeth between 3-4 and 13-14 years of age. Dent. Practitioner, 9:109, 1959. Ditto, W. S., and Hall, D. L.: A survey of 143 periodontal 'l)ases in terms of age and occlusion (Abstract). Am. J. Orthodontics, 40:234, 1954. Dixon, D. A: Observations on submerging deciduous molars. Dent. Practitioner, 13:303, 1963. Douglas, B. L., and Douglas, W.: Clinical observations on replantations of upper anterior teeth. Oral Surg., 7:27, 1954. Dunlop, R.: Habits: Their Making and Unmaking. New York. Liveright, 1932.

Duyzings, J. A C: Nasenatmung bzw. Mundatmung und ihre Folgen fur die Form des Gesichtes wie auch die Form und Funktion des Gesamtk6rpers. Fortschr. Kieferorthopadie, 3:289,1963. Emslie, K D.: Malocclusion and periodontal health. Report of the 30th Congress. European Ortho dont. Soc. p. 271. The Hague. Holland, 1954. Englehardt, H. G., and Hammer, H.: Pathologie und Therapie der Zahnwurzelfrakturen. Deutsche Zahn. Ztschr., 17:1278, 1961. Epstein, L. 1.: Trauma tic injuries to anterior teeth in children. Oral Surg., Oral Med., and Oral Path., 15:334, 1962. Geiger, A M.: Occlusal studies in 188 consecutive cases of periodontal disease. Am. ]. Orthodontics 48:330, 1961. Cranerus, K: Some clinical aspects of the problems of impacted upper canines. Tr. European Orthodont. Soc., annual, 1961. Hallett, G. E. M., and Weyman, ].: Fourteen cases of congenital absence of canines. Brit. Dent. J., 97:228, 1954. Haryett, R. D., Hansen, F. C, Davidson, P.O., and Sandelands, M. L.: Chronic thumbsucking: The psychologic effects and the relative effectiveness of various methods of treatment. Am ]. Orthodontics, 53:569, 1967. Hennis, 1.: Zur Frage der Genese und Therapie des unechten und echten Diastemas. Stoma, 17:150, 1964. Holloway, P. J., Swallow, J. N., and Slack, G. L.: Child Dental Health, A Practical Introduction. Baltimore, Williams & Wilkins, 1969. Ingervall, B.: The influence of orthodontic appliances on caries frequency. Odont. Revy., 13:175, 1962. James, P. M. C: Survey of dental and gingival conditions in school children. Proc. Roy. Soc. Med., 56:620, 1963. [ann, H. W., [ann, G. K, Malone, H. D., and Ward, N. M.: Visceral swallowing and malocclusion. J. Speech & Hearing Dis., 26:334, 1961. Johnson, E., and Taylor, K C: A surgical orthodontic approach in uprighting impacted mandibular second molars. Am J. Orthodontics, 61:508, 1972. Johnson, R., and Baldwin, C, Jr.: Maternal anxiety and child behavior. J. Dent. Children. 36:87, 1969. Kantorowicz, A: Die Bedeutung des Lutschens fur die Entstehung erworbener Fehlbildungen. Fortschr. Kieferorthopaed, 15:109, 1955. Kingsberg, J.: Effective management of juvenile periodontitis (periodontosis): Case report. New York State D. J., 38:71, 1972. Klein, E. T.: The thumb-sucking habit: Meaningful or empty. Am. J. Orthodontics, 59:283,1971. Kortsch, W. E.: Speech defects in a tongue-thrust group. J. A. D. A., 67:698, 1963. Kravitz, H.: Lip biting in infancy. J. Pediatrics, 65:136, 1964. Linder-Aronson, S.: The effect of premature loss of deciduous teeth. Acta odont. scandinav., 18:101, 1960. Lindner, S. L.: Das Saugen an den Fingern. Lippert usw. bei den Kindem. [ahrb. f. Kinderh., 14:68, 1879. McClure, F. J.: Diet and dental caries. J. A D. A, 62:511, 1961. Medina, C A.: Oral manifestations of vitamin deficiencies. Oral Surg., Oral Med. & Oral Path., 9:1060, 1956.

166 . Guidance of Occlusal Development Nadler, S. C.; Detection and recognition of bruxism. J. A. D. A., 61:470, 1960. Nizel, A. D.: Nutrition in Clinical Dentistry. Philadelphia, W. B. Saunders, 1960. Palmer, J. M.: Tongue thrusting: a clinical hypothesis. J. Speech Hearing Dis., 27:323, 1962. Quintarelli, 1.: Sulla etiopatogenesi del diastema interincisivo superior, Minerva Stornatol., 11:465, 1962. Reitan, K.: Orthodontic treatment of patients with psychogenic, muscular and articulation disturbances. Tandlaegebladet, 75: 1182, 1971. Rendle-Short, J.: The history of teething in infancy. Proc. Roy. Soc. Med., 48:132, 1955. Rogers, A. P.: Evolution, development and application of myofunctional therapy in orthodontics. Am. J. Orthodontics & Oral Surg., 25:1, 1939. ---: Myofunctional treatment from a practical standpoint. Am. J. Orthodontics & Oral Surg., 26:1131, 1940. ---: A restatement of the myofunctional concept in orthodontics. Am. J. Orthodontics, 36:845, 1950. Rogers, A. P., Dinham, W. R, and Logan, H. L.: Symposium on muscle function. Int. J, Orthodontics & Oral Surg., 16:254, 1930. Romans, A. R., and App, G. R: Bacteremia, a result from oral irrigation in subjects with gingivitis. J. Periodont., 42:757, 1971. Russell, A. 1.: International nutrition surveys: A summary of preliminary dental findings. J. Dent. Res., 42 [Suppl.], 233,1963. Salzmann, J. A.: Rate and direction of orthodontic change and effect on incidence of caries in 500 adolescents following caries, filling or extraction of first permanent molars. J. A. D. A., 26:1991, 1939. --: Rapid orthodontics. J. A. D. A., 29:1230, 1942. ---: Prevention and interception of malocclusion, Am. J. Orthodontics, 34:732, 1948. ---: Developing normal occlusion. ew York State D. L 18:3, 1952. ---: Orthodontic approach to the interception and treatment of oral habits in children. J. Dent. Children, J. Dent. Children, 19:90, 1952. ---: Effect of postadolescent face growth on orthodontic restults. Am. J. Orthodontics, 43:698, 1957, ---: Dento-rnaxillo-facial orthopedics: etiology and prevention. Am. J. Orthodontics, 43:242, 1957. ---: An answer to "How much orthodontics shall the pedodontist do?" Am. J. Orthodontics, 44:630, 1958.

---: Orthodontic principles and prevention in the everyday practice of dentistry. J, Canad. D. A., 27:81, 1961. Salzmann, J. A., and Ast. D. B.: The Newburgh Kingston fluorine study. IX. Dentofacial growth and development cephalometric study. Am, J. Orthodontics, 41:674, 1955. Scherp, H. W.: Dental caries: Prospects for prevention. Combined utilization of available and imminent measures should largely prevent this ubiquitous disease. Science, 173:1199, 1971. Schour, I., and Massler, M.: Effects of dietary deficiencies upon the oral structures. J. A. D. A., 32:714; 871; 1022; 1139, 1945. Sewerin, I.: Prevalence of variations and anomalies of the upper labial frenum. Acta Odont. Scandinav.. 29:487, 1971. Sinclair, V., and Goose, D. H.: The periodontal condition of grammar school children in cheshire. Brit. D. J., 121: 420, 1966. Stanhope, E. D.: A "buried" tooth containing an amalgam filling. Brit. D. L 81:392, 1946. Suomi, D., et at.: Oral calculus in children. J. Periodont., 42:341, 1971. Thilander, B., and [akobsson, S. 0.: Local factors in impaction of maxillary canines. Acta odont. scandinav., 26:145, 1968. Trott, J. R, Chappell, R, and Borrow, 1.: Gingival health and dental health attitudes in 766 Winnipeg high school students. J. Can ad. D. A., 33:319,1967. Tulley, W, J.: Cineradiographic studies of tongue behavior. D. Practitioner, 10:135, 1960. Tuverscn, D. 1.: Orthodontic treatment using canines instead of missing maxillary lateral incisors. Am. J. Orthodontics, 58:109, 1970. Warrer, E.: Simultaneous occurrence of certain muscle habits and malocclusion. Am. J. Orthodontics, 45:365, 1959. Watson, D. C.: Retraction of upper incisors with the oral screen. Brit. D. L 112:501,1962. Weidemiiller, D., and Weidemiiller, B.: Die kieferorthopadische Behandlung hartnackiger Lutscher- ein psychologisches Problem. Deutsche zahn. Zeitsch., 16: 1045, 1961. Whitman, C. 1., and Rankow, R M.: Diagnosis and management of ankyloglossia. Am. J. Orthodontics, 47:423, 1961.

13 Radiography in Orthodontics The following information useful in orthodontics can be gained from radiograms: 1. General development of the dentition: presence, absence, and state of eruption of the teeth 2. Root resorption of deciduous teeth 3. Root formation of permanent teeth 4. Ectopic eruptions 5. Morphologic anomalies of teeth 6. Pathologic conditions in the dentofacial area 7.Cephalometric lateral radiograms for dentofacial analysis 8. Cephalometric posteroanterior radiograms for symmetry analysis 9. Temporomandibular radiograms for diagnosis of TM disturbances 10. Character of the alveolar bone 11.Evidence of present or past pathologic conditions or morphologic abnormalities 12. Estimate of skeletal age - from radiograms of the carpals

body of the dentist or of the dental auxiliary can be measured with a film badge. Protecting the Patient The following measures should be taken to protect the patient when radiographs are made: 1. Use high-speed films 2. Use diaphragms to collimate the x-ray beam 3. Use a lead apron on the patient 4.Use as large a film as possible for intra- and extraoral radiograms 5. Process films carefully to avoid the necessity of reexposure to x-rays. Effect of Therapeutic Radiation on Teeth The teeth can be damaged by therapeutic radiation, but not by x-rays used for dental diagnostic purposes. The xrays used for therapy are in the 275 to 3,000 kilovoltage range, the dose range is between 4,000 and 6,000 rads. The dose for a single dental radiograph varies between 0.15 and 4 roentgens. The effect of therapeutic x-rays on fully formed and erupted teeth is usually seen as a saucer-shaped loss of tooth substance. in the cervical region. In most cases several adjacent teeth are involved. This occurs not only on the interproximal areas but also on the buccal and lingual surfaces. Both anterior and posterior teeth may be affected. Cervical tooth degeneration may progress until the crown separates from the root; often the pulp is exposed.

RADIATION CONTROL Protecting the Operator Exposure of the operator of a dental x-ray machine to radiation can be minimized by the following procedures: 1. Avoid the direct beam of primary radiation. Stand behind a protective barrier to radiation. Use highspeed films. Use a long cord on the timer to permit the operator to stand out of sight of the sources of secondary radiation. Stand at a 45° angle to the path of the central x-ray beam, behind and to the left or the right ear of the patient. 2. 'Wear a lead apron. 3. Do not hold the tube housing the ray-directing cylinder or the film during x-ray exposure. 4. An open-ended, shielded cylinder in place of a pointed plastic directing cone eliminates, controls, and confines scattered secondary radiation. 5. The x-ray machine should be tested for radiation leakage. 6. The amount of x-ray radiation that reaches the

INTRAORAL RADIOGRAPHY Intraoral dental radiograms for orthodontic diagnosis should present clear views of the apices of the teeth. Bitewing radiograms should be obtained to aid in ascertaining the need for fillings. Exposure time varies with the x-ray machine used. The bisecting angle technic in intraoral dental radiography is based on the principle that the rays are directed perpendicularly to an imaginary plane

16 7

168 . Radiography in Orthodontics

82.

that bisects the long axis of the tooth or teeth and the plane of the film. The uses of periapical and bitewing radiograms are as follows: 1. For assessing the degree of development and clacification of the teeth in the deciduous and permanent dentitions 2. To measure crowns of unerupted permanent teeth in order to estimate dentition jaw length adequacy 3. To measure extraction space closure 4.To recognize the presence of caries and periapical infection 5. To detect the presence of supernumerary teeth 6. To detect congenitally missing tooth buds, developing teeth, and missing unerupted teeth 7. To determine jaw bone density 8. To diagnose ankylosed teeth 9.To evaluate position of developing, unerupted teeth 10. To estimate degree of root resorption 11. To detect interproximal caries

The Maxillary Incisor Region Insert the occlusal packet with the pebbled side toward the upper arch and the long axis coincident with the median plane. Direct the central ray at a vertical angle of +65° through the bridge of the nose,

Fig. 13-1. Correct posinon of patient's head for periapical and occlusal examinations of maxillary regions, and for interproximal (bitewing) examination. (From XRays in Dentistry, published by Radiography Markets Division, Eastman Kodak Company)

to the center of the packet. The patient immobilizes the packet with a gentle end-to-end bite. The Mandibular Incisor Region Insert the occlusal packet with the pebbled side toward the lower arch and the long axis coincident with the median plane. Direct the central ray in the horizontal plane through the tip of the chin to the center of the packet. The angle formed by the central ray and -the film plane is approximately -55°. The patient immobilizes the packet with a gentle end-to-end bite.

The Entire Mandibular Arch Insert the occlusal packet with the pebbled side toward the lower arch and the short axis coincident with the median plane. The posterior edge of the packet should be against inner border of the mandible. Direct the central ray perpendicularly to the occlusal plane, through the inferior aspect of the mandible to the center of the packet. The patient's head should be back far enough so that the occlusal plane is perpendicular to the floor. The patient immobilizes the packet with a gentle end-to-end bite.

The Entire Maxillary Arch The occlusal film is inserted with the smooth

Fig. 13-2. Correct position of patient's head for mandibular periapical examination. (From X-Rays in Dentistry, published by Radiography Markets Division, Eastman Kodak Company)

Extraoral Radiography' 169 83.

Fig. 13-3. To radiograph the central incisors have the patient hold the head vertical and insert the occlusal packet pebbled side up (A). (B) Direct the central ray at a vertical angle of -HiS degrees through the bridge of the nose to the center of the packet. The patient immobilizes the packet with a gentle end-to-end bite. (C) This method will yield a radiograph of the maxillary incisor region. (From X-Rays in Dentistry, published by Radiography Markets Division, Eastman Kodak Company)

Fig. 13-4. To radiograph the entire maxillary arch, the occlusal cassette is inserted with the smooth side adjacent to the maxillary occlusal surfaces-the short center axis in the median plane and the long axis directed bucally and the posterior edge abutting the mandibular rami (A). (B) Direct the central ray perpendicularly in the intersection of the medial plane and a coronal plane through the outer canthi of the eyes to the center of the packet. The patient immobilizes, the packet with a gentle end-to-end bite. (C) This procedure will yield a film of the entire maxillary arch.

'.

side adjacent to the maxillary occlusal surfaces, the short center axis in the median plane, and the long axis directed buccally with the posterior edge butted against mandibular rami. Direct the central ray perpendicularly in the intersection of the median plane and the coronal plane through the outer canthi of the eyes to the center of the packet. The patient immobilizes the packet with a gentle end-to-end bite.

EXTRAORAL RADIOGRAPHY Body of the Mandible The arm of the dental chair on the side to be examined is lowered so that the patient may sit sideways. Place the film holder on the headrest and the chair back so that the film is at an angle of +45°.

170 . Radiography in Orthodontics 84.

Fig. 13-5. (AJ To make a film of the mandibular incisor region, insert the occlusal packet with the pebbled side down. The patient inclines her head upward 45 degrees. Direct the central ray in the horizontal plane through thetip of the chin to the center of the packet. (B) The angle formed by the central ray and the film plane is approximately -55 degrees. The patient immobilizes the packet with a gentle end-to-end bite. (e) This method will produce a film of the mandibular incisor region. (From X-Rays in Dentistry, published by Radiography Markets Division, Eastman Kodak Company)

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Fig. 13-6. (A) To make a film of the entire mandibular arch, insert the occlusal packet pebbled side down with the posterior edge against the rami of the mandible. (B) Direct the central ray perpendicularly to the occlusal plane through the inferior aspect of the mandible to the center of the packet. The patient's head should be back far enough so the occlusal plane is perpendicular to the floor. The patient immobilizes the packet with a gentle end-to-end bite. (e) The film will show the entire mandibular arch.

The patient holds the film holder in position with hands at lower corners. The patient's cheek is in contact with the front of the film holder. The median plane of the head is rotated until the body of the mandible is in contact with the center of the film holder, the lower border of the mandible parallel with its lower edge. Direct the central ray at an angle of approximately +250 through the lower molar area on the side being examined to the center of the film.

Extraoral Radiography· 171

Fig. 13-7. (A) To take two lateral jaw views, cover half the 5" x 7" cassette with a lead sheet. (B) Two lateral jaw roentgenograms were taken on one 5" X 7" film in a cassette.

c Fig. 13-8. To make a film of the body of the mandible, the arm of the dental chair is lowered on the side to be radiographed so the patient may sit sideways. (A,B) Place the film holder on the headrest of the chair back so that the film is at an angle of +45 degrees. The patient holds the film holder in position with hands at the lower corrters, The patient's cheek is in contact with the front of the film holder. The nose should be V2 inch from the surface of the cassette; the head is extended backward. The median plane of the head is rotated until the body of the mandible is in contact with the center of the filmholder, the lower border of the mandible parallel with the lower edge of the cassette. (C) Direct the central ray at an angle of about 25 degrees above the horizontal and from a point behind and beneath the condyle so that the central ray passes through the second or third molar on the side to be radiographed. (0) This procedure produces a film of the body of the mandible. Figures 13-8A-13-10 (From X-Rays in Dentistry, pubijshed by Radiography Markets Division, Eastman Kodak Company)

The arm of the dental chair is lowered so that the patient may sit sideways. The patient rotates the upper trunk to face the cassette. Place the cassette on the headrest and the chair back in a horizontal position. Place the patient's nose and chin on the

cassette so that the nose is over the approximate center with the median plane vertical and coincident with the long axis of the film holder. Direct the central ray at an average angle of +700 in the median plane, through a point 1 V2 inches below the

172 . Radiography in Orthodontics base of the skull toward the center of the film. Use two lateral jaw radiograms on one 5 X 7 film taken in a cassette. One half of the cassette is covered with a lead shield when the exposure is made.

The Facial Profile (Lateral View) A line from the tragus of the ear to the ala of the nose is taken as horizontal. The median plane is vertical. The occlusion should be in the rest position. The cassette containing the film is positioned vertically against the lateral aspect of the head, with its lower edge resting on the patient's shoulder. The center of the film should be opposite the zygomatic arch. The patient holds the cassette with the front edge parallel with the median plane of the head. Direct the central ray horizontally and laterally through the anterior nasal spine to the center of the film.

Temporomandibular Radiography Temporomandibular radiograms show the relation of the mandibular condyle to the glenoid fossa and are intended to disclose evidence of pathologic and morphologic deviations. The dense bony structures surrounding the temporomandibular articulation make it difficult to radiograph this area. The patient is seated sideways in the dental chair, and the headrest is adjusted to hold the patient's head stable. A film in a cassette is used. The central ray of the x-ray machine is focused at 2.5 em. above the border of the ear on a line above the external auditory meatus and is directed to the opposite condyle head. The central ray of the x-ray machine is set between 20° and 30° and turned 15° to 20° towards the face. Another method is for the patient to hold the cassette vertically. The side of the face is placed against the cassette so that the contour of the face touches

Fig. 13-9. To radiograph the temporomandibular articulation, the arm of the dental chair is lowered on the side to be examined, to allow the patient to sit sideways. The cassette is placed on the headrest with the chair back in horizontal position. Center the lateral aspect of the temporomandibular articulation on the cassette, rotating the median plane toward the cassette until the zygomatic arch touches it. The lower border of the mandible is parallel to the lower edge. Direct the central ray at an angle of about +75 degrees through the head of the condyle on the opposite side. (From X-Rays in Dentistry, published by Radiography Markets Division, Eastman Kodak Company)

Extraoral Radiography· 173

85. 86.

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the cassette. The central ray is directed downward 15° from a point about 2 inches above and behind the external auditory meatus and towards the condyle nearest to the cassette.

Panradiography Panradiography is a method for exposing the entire dentoalveolar and adjacent jaw region on a single film. This is accomplished by traversing the x-ray tube and film around the patient's head while making a continuous radiographic exposure during the rotation. The x-ray head is attached to one end of a ,.. _ __ __ __ _____- - ~~ - JiL -

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Patient R. M. Age Dimension

Facial Angle (F.H. to N-Pg) Angle of Convexity (N-A-Pg) A-B line to N-Pg Mand. Plane to F.R Y-Axis Occlusal Plane to F.H, 1 to I angle I to Mandibular Plane 5- -A 5- -B Gonion Angle

Downs Range

Mean

Age 7 Years

10 Years, 3 Months

Age 13 Years

82° to 95°

87.8°

82°

83°

83°

-8.5" to + 10°

0°

+6°

+10°

+10°

-4,8° 21.9 59.4° 9S 135.4° 91,4° 82° 80°

-2° 32° 63° 15° 130° 85° 80° 77°

-5° 32° 64° 14° 117° 94° 81° 77°

-6° 32° 66° 15° 133° 92° 82° 77°

126°

132°

132°

132°

-9° to 0° 28° to 17° 66° to 53° 1.5" to 14° 130° to 150.5° 81.5° to 97°

Tweed 116°-135°

The following patient was treated without extraction, although growth was unfavorable: Patient M. M. (Fig. 19-6) Clinical Description. A girl, age 8 years and 6 months with a Class I malocclusion. There is lingual collapse of the mandibular incisor teeth and an abnormal overjet of 12 mm. There is interdental spacing of the maxillary permanent right and left central and lateral incisors. The right and left mandibular permanent central and lateral incisors are erupted (Fig. 19-6A). The right deciduous canine is in position. The first deciduous molar has been exfoliated. The left decidu-

ous canine has been exfoliated, and the space is closed. The left first deciduous molar is in position and the left second deciduous molar has been extracted. The right and left mandibular permanent first molars are erupted. The lower lip rests lingually to the maxillary incisor teeth. At age 9 years and 6 months, after 1 year of treatment, the occlusion is Class I (Angle). The incisor overjet has been reduced to 4 mm. The maxillary right and left permanent central and lateral incisors are in normal alignment. In the mandible the right and left permanent central and lateral incisors are in normal alignment. On the left side the first deciduous molar is in position and the extraction space of the second deciduous

268 . Serial Extraction Fig. 19-6. (A) Patient M. M. Anterior (top) and occlusal (second row) views when patient was first seen at age 8 years and 6 months. There is an overjet of 12 mm. There are space maintainers (third row, left) at the right deciduous first molar space and the left second molar space. (B) (Top) lateral views before treatment. (Center) After 1 year treatment. The overjet and overbite have been reduced, the mandibular permanent canines are erupting and there is sufficient space for the unerupted premolars. (Bottom) After 1 year of observation there is some increase in overbite. Otherwise, the developing occlusion is stable. (C) (Opposite page) Anterior and occlusal views at age 16,4 years out of retention. (0) Lateral photographs at 8 V2 years (left), 10lh years (center), and at 16 years. Facial growth continued to be unfavorable with the mandible showing practically no forward growth, while the maxilla continued to grow forward. However, the dental arches continued to grow forward and show indications of accommodating the permanent teeth in regular alignment without extraction. (E) Tracing of the lateral radiograms at 8lh years shows that the face is retrognathic. The maxillary incisors are in alveolodental protrusion.

Treatment Without Extraction - Case Histories' 269

131.

M.M. 7yrs. ----- 12Yrs. _.-15yrs.

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M.M_ -age 6 yrs.,6 mos. - - -age 9yrs.6 mos. - - --agelOyrs,,6 mos_

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270 . Serial Extraction

133. 134.

molar is available for the eruption of the second premolar. Skeletal Classification. The facial skeletal pattern is Class 2. History. When the patient was first examined she had a space maintainer at the right mandibular deciduous first molar space and at the left mandibular second deciduous molar space. The left deciduous canine space was closed but the right deciduous canine was permitted to remain in place. There had been no attention given to the severe maxillary incisor overbite and overjet. The dynamic dentition of the child cannot be treated piecemeal but must be regarded and treated as a unit.

TWEED'S ORTHODONTIC GUIDANCE When a discrepancy exists between dental arch and alveolar process length (basal bone) and the patient is between the ages of 7% and 8 V2 years, Tweed performs serial extraction as follows: At age 8 years all four deciduous first molars are extracted. If the mandibular permanent incisors are not blocked out or severely crowded, the deciduous canines are maintained in position to prevent too early eruption of the permanent canines. When the first premolar teeth erupt to about the level of the crest of the alveolar mucosa, they are extracted. The deciduous canines also are extracted at this time. When the premolars are extracted 4 to 6 months prior to eruption of the permanent canines, the permanent canines usually shift posteriorly and erupt in the space left by the extracted first premolars. Slight irregularities of the mandibular in-

THE TWEED DIAG OSTIC FACIAL TRIANGLE Tweed conceived the diagnostic facial triangle as a basis for diagnosis and treatment planning. This consists of the following: 1. FMA - the Frankfort-Mandibular Plane Angle. 2. IMA- the Incisor-Mandibular Plane Angle. 3.FMIA-the Frankfort-e Mand ibular Incisor Angle. In addition consideration is given to: A- -B-the A-Point-Nasion-B-Point angle, and S- - the sella-nasion line. Tweed established 25° as the norm for the Frankfortmandibular plane angle (FMA), and 90° as a norm for the mandibular-incisor-mandibular plane angle (IMA). By extending the line through the

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cisor teeth may show self-correction at this time. The second deciduous molars should be maintained in the dental arch to prevent the permanent first molars from shifting and inclining forward. Tweed summarizes the philosophy on which his therapy is based as follows: 1. The mandibular incisor teeth are in normal axial inclination when related to the Frankfort plane at approximately 65° (FMIA). 2. The mandibular incisors should be positioned over basal bone (the medullary bone of the respective basal arches) at 90° ± 5° in relation to the mandibular base (lMPA). Serial extraction objectives are as follows: 1. Facial balance and harmony 2. Stability of the posttreatment dentition 3. Healthy oral tissues 4. Efficient function

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Front view showing location of wire for labial root torque.

ARCHWIRE LOOPS The archwire, when first adjusted, possesses a variable amount of stored energy depending on its spring design. After insertion there is a gradual loss of force until the minimum pressure is attained. Loops increase the length of the wire between attachments, thereby reducing force and increasing the range of the activity of the archwire. However, the force exerted by a loop depends on the amount of deflection it undergoes when it is attached to a tooth. Vertical Loops. Vertical loops are intended to increase the force delivered to the teeth. Vertical loops under compression have a greater range of activation when not expanded and then compressed. Excessive expansion of the loops in the incisor region can cause the anterior teeth to tip forward. Vertical loops aid in resisting permanent crimping of wires between attachments, so that variations in bracket heights and tooth irregularities will not readily produce permanent distortions of the archwire, If the distance of the deflection of the wire to the bracket seat is not increased, vertical loops reduce the force exerted by the archwire, If loops are placed in the archwire between the brackets, the length of the' "lever arm" (the force-producing part) is increased. A lighter force can be exerted provided the

Fig. 20-11. (Top) Second-order bends in the archwire produce mesial crown tipping. (Center) Passive arch without second-order bends. (Bottom) Second-order bends produce distal tipping (tipback bends). ote that two staples are attached to each band.

282 . Biomechanics in Orthodontic Therapy

147. 148.

Fig. 20-13. (Top) An open-coil spring is inserted under compression to open space for insertion of artificial lateral incisor. (Center) A sliding jig against the maxillary canine with intermaxillary elastic moves the canine distally. (Bottom) Sliding jig against the molar is used with intermaxillary elastics to move the maxillary molar distally. Fig. 20-12. (Top) Contraction coil spring in place on the sectional appliance. The anterior end of the straight wire extending from the spring is secured by wrapping it several turns around the ribbon wire portion of the sectional appliance in front of the canine attachment. The posterior end is wrapped around a portion of end tubing that is allowed to project past the distal end of the buccal tube. (Bottom) Contraction coil spring in action. This is activated by pulling the tightly wound coil spring open and wrapping the straight wire sections of the spring around the anterior and posterior ends of the sectional appliance. If the portion of the spring to be secured around the ends of the sectional arch wire is softened by heating, it can be closely adapted. (Courtesy of F. . Weber) distance of deflection is not increased. When the archwire with a loop is not adapted closely enough to the teeth and the distance of deflection is increased, the resulting force is accordingly increased regardless of the small diameter of the wire. When a Single vertical loop is used to open space, the arch wire is fixed in the brackets by compressing

the legs of the open loop. When the loop tends to assume its original position, the teeth are moved apart. Loops can also be used to rotate teeth, since they enable immediate bracket engagement through their increased resiliency. The loop creates a force of greater duration that rotates the tooth toward the desired position. A single, closed vertical loop can be used to close space. The legs are compressed, and as the loop expands it draws the horizontal extensions of the wire arch together along with the teeth. Double vertical loops are used to rotate and to move teeth labial1y and lingually into line.

Horizontal Loops. Horizontal loops are used to reduce force in a vertical or occlusogingival direction permitting immediate bracket engagement in severely malaligned teeth which need to be elevated or depressed. Helical Loops. When a helical loop is used the force is reduced, but the range of force activity is

Elastic Force . 283 149. 150.

increased. The amount of force exerted by a helical loop varies with the size of the loop and the size of the coil. Open Loops. Open or continuous loops, when activated by compressing its legs, will tend to push the horizontal extensions apart, increasing the length of the archwire. A closed loop or reversed loop, when activated by compressing its legs, will tend to draw the horizontal extensions toward one another, shortening the arch wire length. Torquing Loops. The torquing loop is a compressed vertical loop which may be seated between twin brackets or adjacent to single brackets. It is corttoured to press against the gingival surface of the crown and is activated by ligating the archwire in the brackets. When the buccal segments are stabilized, it tends to exert lingual root movement. It also stabilizes vertical loops and prevents their impinging on the labial or gingival mucosa.

ELASTIC FORCE Force produced by elastics on a tooth or teeth depends on the type of elastic used, the site of application, the distribution of the force, and the direction, length, diameter and contour of the root of the tooth to which the force is applied, the character of the alveolar process, the amount of tooth rotation, and the health, age, and cooperation of the patient. Rubber elastics, according to Beshara and Andreasen, maintain a more constant force over a 3week period than plastic" Alastics," and the elastic force produced varies less. Alastics show more deformation. Elastics can be used for intramaxillary and intermaxillary tooth movement and in combination with extraoral anchorage. Intramaxillary elastics are used between two points in the same dental arch. Intermaxillary elastics are used between the maxillary

6.2 oz.

Fig. 20-14. (Top) The upper arch is fitted with an anterior retraction mechanism that uses a .010 X .020 flat wire spring. The anterior segment is fabricated of .021 X .028 tube in which the .0lD X .020 spring is placed. A lower base arch is used to depress the anterior teeth and reciprocally elevate the posteriors. An inner wire from canine to canine is being used to level and rotate the anterior teeth. (Bottom) A canine retraction spring. (Courtesy C. J. Burstone)

and the mandibular dental arches to retract the maxillary dental arch or to bring the mandibular dental arch forward. Elastics may be used also vertically to bring teeth in opposing dental arches into occlusion. Elastics of the same dimensions are not constant in the amount of pull they exert. They are modified by the length of time since their manufacture, by the quality of the latex from which they are made, and by the length of time they are subjected to the oral fluids.

9.8

3.4 oz.

6.6 1IIIIl.

00.

6. 6

-------1 2.5 11IIII.

0.9 oz. 10.5 lUI. 8.1. oz. 0.900.

A 1).7

00,

B Fig. 20-15. Vector diagrams, with intermaxillary elastics of the mouth closed (left) and open (right). (Courtesy S. M. Bien)

284 . Biomechanics in Orthodontic Therapy

152. 151. 153.

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1 Fig. 20-17. (Top) Sliding hook against maxillary canine with intermaxillary elastic to close space distal to canine. (Bottom) The space distal to the canine now is closed.

Fig. 20-16. Space diagrams of intermaxillary elastics with the mouth closed (top) and open (bottom). (Courtesy S. M. Bien) Most of the fixed and some removable appliances rely on elastic force to varying extents. When intermaxillary elastics are used during the growth period, there is a greater tendency for the anchor teeth in the mandible to move mesially. To move maxillary teeth distally by means of intermaxillary elastics, it is necessary to use minimum elastic force during the day when the mouth is open. Heavier intermaxillary elastics, the headgear, or both, may be used at night when the mouth is closed.

Fig. 20-18. Lingual and buccal elastics are used to close a space; (lop) occlusal and (bottom) side views. The larger the elastics, the lighter the force. This produces distal movement of the canine while the molars remain essentially stationary. If forward movement of the molars is desirable, the elastic on the buccal surface is attached to hooks on the round lingual arch mesial to the canines, and smaller elastics are used.

Bibliography· 285 When Class II intermaxillary elastics are used (from maxillary incisors to mandibular molars) the mandibular incisors and the teeth in the entire dental arch are moved forward, in many cases to an objectionable extent. The extraoral headgear with spring traction bar exerts the smallest amount of undesirable force. Force exerted by intermaxillary elastics is in an anteroposterior direction when the mouth is closed and the jaws are in rest position. When the jaws are opened, a vertical component of force is introduced which tends to pull the posterior part of the maxillary dental arch downward. Untoward forces show themselves in a downward displacement of the maxillary molar teeth. The force of intermaxillary elastics can cause an increase in the angle of the occlusal plane. Those patients who experience the greatest amount of growth during treatment exhibit the least change in the inclination of the occlusal plane, and those that show the least growth during treatment show the greatest change in the occlusal plane. Subsequent to treatment, the patients exhibiting most growth during treatment show the greatest tendency of the plane to return to the original inclination, and those who show the least growth show less tendency to return to the original inclination. The attempt to establish normal interarch relation of the teeth by intermaxillary force results in failure when the patient brings the mandible forward bodily. A dual bite may be present before orthodontic therapy is started or it may be established by the patient when strong elastics are inserted. The patient should be taught how to use the elastics and should be impressed with the importance of cooperating in wearing elastics.

BIBLIOGRAPHY Adams, C. P.: The soldering of stainless steel for remova ble appliance construction. D. Practitioner, 6:334, 1955. ---: Orthodontic doctrine and mechanical treatment methods. Am. J. Orthodontics, 46:811, 1960. Aderer, J.: The soldering of half-round points and socalled finger springs to arch wires. Int. J. Orthodontics, 15:796, 1929. Andreasen, G. F. and Bishara, S.: Comparison of alastik chains to elastics involved with intraarch molar to molar forces. Am. J. Orthodontics, 60:200, 1971. Angle, E. H.: The latest and best in orthodontic mechanisms. Dental Cosmos, 70:1143,1928; 71:164,260,409,1929. Armstrong, M. M.: Controlling the magnitude, direction and duration of extraoral force. Am. J. Orthodontics, 59:217, 1971. Backofen, W. A.: Heat treating stainless steel for orthodontics. Am. J. Orthodontics, 38:755, 1952. Beshara, S. E. and Andreasen, C. F.: A comparison of time

related forces between plastic elastics and latex elastics. Angle Orthodontist, 40:319, 1970. Bien, S. M.: Analysis of the components of forces used to effect distal movement of teeth. Am. J. Orthodontics, 37:508, 1951. ---: The mechanism of tooth movement: An investigative approach. New York J. Dent., 36:191,1966. Bien, S. M., and Ayers, H. D., Jr.: Solder joints and rustless alloys. J.A.D.A., 58:74,1959. Boman, V. R: A radiographic study of response to torquing spring action. Angle Orthodontist, 32:54, 1962. Born, H. S.: Some facts concerning the open coil spring. Am. J. Orthodontics,41 :917,1955. Borschke, A.: Vorschlage zur Messung der Kraftwirkung verschiedener Regulierungs-apparate mit besoriderer Beri.icksichtigung von intermaxillaren Gummizilgen. Zeitschr. Stornatol., 18:448, 1969. Buchner, H. J.: Anchorage considerations in the treatment of Class II, Division 1 malocclusions. Angle Orthodontist, 27:217, 1957. Burstone, C. J.: Rationale of the segmented arch. Am. J. Orthodontics, 48:805, 1962. Burstone, C. L Baldwin, J. L and Lawless, D. T.: The application of continuous forces to orthodontics. Angle Orthodontist, 31:1,1961. Callender, R S.: The effect of heat treatment on resiliency of orthodontic wires. J. D. Res., Abstracts, 1962. Crabb, J. J. and Wilson, J. J.: The relation between orthodontic spring force and space closure. D. Practitioner, 22:233,1972. Drenker, E. W.: Unilateral cervical traction with a Kloehn extraoral mechanism. Angle Orthodontist, 29:201, 1959. Enlow, D. H.: A study of post-natal growth and remodeling of bone. Am. J. Anat., 110(2):79, 1962 ---: Principles of Bone Remodeling. Springfield, Ill. Charles C Thomas, 1962. Evans, F. G.: Methods of studying the biomechanical significance of bone form. Am. J. Phys. Anthropol., 11 :413, 1953. ---: Studies' in human biomechanics. In Miner, R. W., (Ed): Dynamic Anthropometry. Ann. N. Y. Acad. Sci. 63: Art. 4, 586-615, 1955. -. --: Stress and strain in bones. Their relation to fractures and osteogenesis. Springfield, 111. Charles C Thomas, 1957. ---: Biomechanical Studies of the Musculo-Skeletal System. Springfield, Ill. Charles C Thomas, 1961. Flourens, J. P.: Recherches Sur Ie' Developpment des Os et des Dents. Paris, 1842. ---: Theorie Experirnentale de la Formation des Os. Paris, 1847. Fogel, M. S. and Magill, J. M.: A fundamental re-appraisal of popular techniques with a collective approach toward appliance therapy. 55:705, 1969. Freeman, R. S.: Are class II elastics necessary? Am. }. Orthodontics, 49:365, 1963. Funk, A. c.: Mandibular response to headgear. 53:182, 1967. Gaston, N. G.: Chrome alloy in orthodontics. Am. ). Orthodontics, 37:779, 1951.

286 . Biomechanics in Orthodontic Therapy Gianelly, A: Mandibular cervical traction in the treatment of class I malocclusion. Am. J, Orthodontics, 60:257, 1971. Goldstein, M. C: Elastic-thread ligature as an auxiliary for tooth movement. Am. J. Orthodontics, 45:6,1959. Gould, 1. E.: Mechanical principles in extra-oral anchorage. Am. J. Orthodontics, 43:319,1957. Haack, D. C: The science of mechanics and its importance to analysis and research in the field of orthodontics. Am. J. Orthodontics, 49:330,1963. Haack, D. C, and Weinstein, S.: The mechanics of centric and eccentric cervical traction. Am. J. Orthodontics, 44:346, 1958. Haynes, S., and Jackson, D.: A comparison of the mechanics and efficiency of twenty-one orthodontic expansion screws. D. Practitioner, 13:125, 1962. Higley, L. B.: Anchorage in Orthodontics. Am. J. Orthodontics 55:791, 1969. Hixon, E. H., et al.: Optimal force, differential force and anchorage. Am. J. Orthodontics, 55:437, 1969. Luffingham, J. K: Pressure exerted on teeth by the lips and cheeks. D. Practitioner, 19:6], 1968. Iyer, V. S.: Reaction of gingiva to orthodontic force: a clinical study. J. Periodont., 33:26, 1962. Janssen, M.: On Bone Formation. Its Relation to Tension and Pressure. London, Longmans, ]920. Johnson, A L., Appleton, J, L. T., and Rittershofer, L. S.: Tissue changes involved in tooth movement. Int. J, Orthodont., Oral Surg., & Oral Radiog., 12:889, ]926. Joffe, B. M.: Galvanic current generated by an orthodontic appliance. J.D.A South Africa, 17:78,1962. Jolly, M.: The formation of bone. D. J. Australia, 25:133, 1953. Kaletsky, T.: An additional report on further studies in electric pulp testing. New York J. Dent. 7:81, 1937. ---: Management of traumatized pulps. Am. J. Orthodont. & Oral Surg., 30:93, 1944. King, E. W.: Cervical anchorage in Class II, Division 1, treatment, a cephalometric appraisal. Angle Orthodontist, 27:98, 1957. Kloehn, S. J,: Guiding alveolar growth and eruption of teeth to reduce the treatment time and produce a more balanced denture and face. Angle Orthodontist, 17:10, 1947. ---: An appraisal of the results of treatment of Class II malocclusion with extraoral forces. Tr. European Orthodont. Soc., p. 112, 1961. Krebs, A: Expansion of the midpalatal suture studied by means of metallic implants. Trans. European Orthodont. Soc., 34:163, 1958. Kressner, A: Die Umstellung zur Nasenatmung durch die Gaumennahterweiterung, vom Standpunkt des Rhinologen. Fortschr. Kieferorth, 15:228,1951. 'Lindquist, J. T.: Indirect band technic. Angle Orthodontist, 29:11, 1959. Lischer. B. E.: Mechanical treatment of dental anomalies. J.AD.A & Dent. Cosmos 25:397, 1938. Luffingham, J. K: Pressure exerted on teeth by the lips and cheeks. D. Practitioner, 19 :61, 1968.

agai, K: Behavior of metals in oral cavity. J, Nihon Univ. School Dent., 1:203, 1959. agarnoto, G.: Contraction coil spring, its uses and how to make it. Am. J. Orthodontics & Oral Surg., 33:392, 1947. ---: The significance of proper mechanical therapy in orthodontic treatment. Am. J. Orthodontics, 35:269, 1949. Nyquist, G.: The biological effect of monomeric acrylic. Internat. D. J., 14:242, 1964. Paffenbarger, G. C, Sweeney, W. T., and Isaacs, A.: Wrought gold wire alloys, physical properties, and a specification. J,A.D.A, 19:2061, 1932. Parker, W. S.: A technique for treatment with cervical gear. Angle Orthodontist, 28:198, 1958. ---: Mechanical principles and orthodontic appliances. Angle Orthodontist, 30:241, 1960. Poulton, D. B.: The influence of extraoral traction. Am. J. Orthodontics, 53:8, 1967. Rauch, E. D.: Torque and its application to orthordontics. Am. J. Orthodontics, 45:817, 1959. Rogers, A. P.: Myofunctional treatment from a practical standpoint. Am. J, Orthodontics & Oral Surg., 26:113], ]940. Salzmann, J, A.: The biophysics of bone and success in orthodontic therapy. Am. J. Orthodontics, 45:606, 1959. Sandstedt, c.: Einige Beitrage zur Theorie der Zahnregulierung. Nordisk. Tand. Tid., 5:236, ]904; 6:]41, 1905. Sather, A H., Mayfield, S. B. and Nelson, D. H: Effects of muscular anchorage appliances on deficient mandibular arch length. Am. J. Orthodontics, 60:68, ]971. Simon, P.: System einer biologischmechanischen Therapie der Gebiss-Anomalie. Berlin, H. Meusser, 1933. Smith, R., and Storey, E.: Optimum force for optimum tooth movement. Australian J, D., 56:291, 1952. ---: The importance of force in orthodontics, design of cuspid retraction springs. Australian J. D., 56:291, 1962. Sorensen, O. J,: The sectional arch in CLass II extraction cases. Angle Orthodontist, 30:174, 1960. Stevenson, W.: Extraoral anchorage and traction in orthodontics. Brit. J, D., 122:309, 1967. Stoner, M. M.: Past and present concepts of anchorage preparation. Angle Orthodontist, 28:176, 1958. -,--: Force control in clinical practice. I. An analysis of forces currently used in orthodontic practice and a description of new methods of contouring loops to obtain effective control in all three planes of space. Am. J. Orthodontics, 46:163,1960. Storey, E., and Smith, R.: Force in orthodontics and its relation to tooth movement. Australian J. D., 56:11, 1952. ---: Bone changes associated with tooth movement: A radiographic study. Australian J. D., 57:57, 1953. Susarni, R., and Akiyama, K: Some physical properties of rubber elastics. J. Osaka Univ. Dent. Soc., 4:485, 1959. Sved, A.: The behavior of arch wires in fixed attachments. Int. J. Orthodontics & Oral Surg., 23:683,1947. ---: The application of engi neeririg methods to orthodontics. Am. J, Orthodontics, 38:399, 1952. Taylor, N. 0.: Problems involved in the study of wrought

Bibliography· 287 gold alloys for orthodontia. Int. J. Orthodontics, 17:1033, 1931. Thorne, H.: Experiences on widening the median maxillary suture. Report of the 32nd Congress, European Orthodont. Soc. Annual 1956. Timoshenko, 5.: Strength of Materials. ed. 3. New York, Van ostrand, 1955. Tirnoshenko, 5., and Young, D. H.: Engineering Mechanics. ew York, McGraw-Hill, 1956. Tweed, C. H.: The soldering technic for steel arch wire. Angle Orthodontist, 11 :68, 1941. Van der Linden, F. P. G. M.: The removable orthodontic appliance. Am. J. Orthodontics, 59:376, 1971. Waldron, R.: The dynamics of the new Angle mechanism, as observed by a non-Angle man. Int. J. Orthodontics, Oral Surg. & Radiog., 17:1113, 1931.

Weinstein,S.: Minimal Forces in Tooth Movement. Am. J. Orthod., 53:881-903, Dec. 1967. Weinstein,S., and Haack, D. c.: Theoretical mechanics in practical orthodontics. Angle Orthodont., 29:177, 1959. Weinstein,S., et al.: On an equilibrium theory of tooth position. Angle Orthodontist, 33:1,1963. Wilkinson, J. V.: Some metallurgical aspects of orthodontic stainless steel archwires. Am. J. Orthodontics, 48:192, 1962. Williams, R. V.: Orthodontic metallurgy. Int. J. Orthodontics, 15:219, 1929. ---: Orthodontic alloys. Int. J. Orthodontics, 11 :1,1935. Ziegler, J. T.: The comparative merits of cementing orthodontic bands on non-dehydrated and air-dried teeth: A clinical study (Abstract). Am. J. Orthodontics, 45:869, 1959.

21 Appliance Construction and Use An orthodontic appliance is a means to an end. It is not an end in itself as is the case with operative and prosthetic appliances that replace lost dental and oral tissues. Some appliances are more effective than others in producing desired results in specific types of malocclusion. Placement of appliances in the mouth should be accomplished gradually, and active force should be postponed until the patient has become accustomed to the presence of the appliances in the mouth. The patient should be advised that some temporary tenderness may develop. Appliances should be removed when not absolutely necessary.

Overlapping portions of bands on the occlusal surface of teeth should be removed. All excess cement, especially on gingival and occlusal surfaces, should be removed. All loose bands should be recemented without delay.

LINGUAL APPLIANCES The fixed appliance is attached to the teeth; it is removable by the operator. Anchorage is dependent on the resistance offered by teeth (anchor teeth). Bodily movement and rotation of teeth with labiolingual appliances are not easily obtained although they readily permit tooth movement by tipping. Functional freedom of the teeth is more possible with labiolingual appliances than witl"~ multi banded appliances that keep the teeth in a more rigid state. Space closure with labiolingual appliances does not lend itself readily to paralleling the roots of teeth. When gentle pressure is used, teeth can be moved with only slight axial inclination. Teeth adjacent to an extraction space should be banded in order to obtain parallel root movement. Axial inclinations of the moved teeth adjacent to an extraction space will correct themselves occasionally when a retaining appliance is worn. Another method of space closure is to bring the tooth to be moved into the extraction space into contact with the tooth on the opposite side of the extraction space. Light spring pressure then is exerted at the gingival margin of the tooth being moved, while the adjacent tooth acts as a stop, until the axial inclination of the moved tooth is corrected. Rotation of Teeth. While auxiliary springs can be of assistance in rotating teeth, lingual appliances require bands to be cemented to the teeth to be rotated. Brackets or staples are attached to the mesial and the distal thirds of the band for ligating the teeth to the arch wire in order to obtain rotation. Elastic or steel ligatures also may be used. To correct tooth irregularities in the mandibular arch, a lingual archwire (0.036 inches) with loops can be used. By bending the archwire slightly down-

BASIC REQUIREME S OF ORTHODONTIC APPLIANCES Appliances should possess the following qualities: 1. Permit control of the degree, distribution, duration, and direction of the force they exert 2. Be harmless to the oral tissues and not adversely affected by oral secretions 3. Allow teeth and soft oral tissues to function normally 4. Allow wearer to maintain oral hygiene. 5.Exert sufficient force or offer sufficient anchorage resistance to induce histologic bone changes necessary for desired orthodontic tooth movement 6. Respond to the control of the operator 7.Allow movement of individual teeth or of groups of teeth in desirable directions Safety Measures in Appliance Therapy Appliances should be examined to note that the bands are properly soldered, aligned, and cemented in proper position in order to avoid undesirable movement of teeth, caries formation, and unnecessary interruption of treatment. Archwires should be examined for brittleness and unwanted crimping. Irritation of the mucous membranes can result from rough ends or archwires, Small, smooth wires soldered to the lingual surface of bands afford a grip for the band remover and facilitate removal.

28 8

Lingual Appliances . 289 Fig. 21-1. To separate for banding, the elastic ture is drawn through dental floss (left) and tightly (center and right).

teeth ligawith tied

Fig. 21-2. The Mershon lingual and the labial arch. A, buccal tube, the inner dimension varies with the type of

archwire used, usually for .040 in. wire; B, stop spring or Porter loop, a .022 in. diameter wire; C, labial arch wire, diameter varies but is usually .040 in.: D, intermaxillary hook, usually .036-in. diameter; E, Mershon half-round vertical molar tube, .10 long; F, half-round wire post to fit the 'half-round tube; G, lingual arch lock wire, .022-in. diameter; H, auxiliary spring may be .022-in. or .020° diameter; I, lingual arch, .040 in. or lesser diameters may be used; J, auxiliary spring stabilizer wire, .022-in. diameter; K, anterior band material, .040- or .003-in. thick and .1Bo-in. wide. L, ligature stop .020-in. diameter; M, band material, .006-thick and .1BO-in. wide.

ward close to the molar bands compensation is obtained to prevent shifting the molars forward when intermaxillary elastics are used. Intermaxillary elastics are not to be used until individual tooth irregularities in the mandibular dental arch are eliminated.

The Mershon Lingual Appliance

at intervals during dental development. He did not consider treatment completed before the eruption of the permanent dentition is completed. Mershon advocated correcting molar relationship before aligning other teeth. Construction. 1. Adapt bands to the second deciduous molars, or in their absence, to the first permanent molars. Solder half-round vertical tubes to the lingual surface of the maxillary molar bands

Mershon advocated lingual appliances and treating , Fig. 21-3. (Left) Types of locks used in removable lingual arch appliances. (Right) Labial arch loops used as stops. These can be brought against or away from the molar buccal tubes. (Courtesy Lowrie J. Porter)

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290 . Appliance Construction and Use Fig. 21-4. (Top left) Lingual appliance used to replace maxillary left lateral incisor tooth, and auxiliary spring to move the maxillary left canine mesially. (Top right) Lingual appliance with auxiliary springs to move maxillary right central incisor and left lateral incisor. (Bottom left) Lingual appliance. (Right) Appliance used to move canine in palatal eruption.

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and to the lingual surface of the mandibular molar bands. 2. Take an impression with bands seated but not cemented to the molar teeth. Remove the bands from the teeth and fit them into position in the impression. Cover the inner surface of the bands with a thin film of wax to facilitate their removal from the cast to be made. Pour the impression in stone and separate the cast when set. 3. Adapt an 0.040-inch archwire around the lingual surfaces of the teeth on the cast. Solder two halfround posts to the archwire so that they fit into the half-round tubes attached to the molar bands. Solder lock-wires to the end of the arch wire.

4. Cement the bands to the molar teeth. Attach auxiliary springs of 0.016- or 0.020-inch round wire as desired for movement of individual or groups of teeth. Tooth movement is accomplished by means of the archwire and by auxiliary springs attached to the archwire. Attachment of Auxiliary Springs: The following should be observed: 1. Attach auxiliary springs on the gingival aspect of the archwire. 2. Use low-carat solder for soldering auxiliary springs to avoid removing the temper and elasticity of the spring. Melt a small piece of solder on the

Lingual Appliances' 291

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Fig. 21-7. Auxiliary springs on the lingual appliance used to open space for a lateral incisor.

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Fig. 21-6. The Mershon lingual arch with auxiliary springs as it is positioned to achieve different effects: A, intercanine expansion; B, expansion of the anterior portion of the arch; C, expansion of the canine and premolar region; 0, general expansion of the arch, using recurved springs; E, opening space for canine; F, anterior movement of lateral incisors; G, anterior movement of incisor teeth; H, closure of space between central incisors; I, opening space for lateral incisor. (Courtesy Lowrie J. Porter)

spring wire and another piece of solder on the archwire at the point where the spring is to be attached. Attach the spring by joining the solder covered parts. 3. Attach auxiliary springs to the main arch wire

Fig. 21-9. (A) Solid lines show passive auxiliary spring ar d dashed lines show activation to clove premolars buccally. (B) Active spring moves molars and premolars, and when spring wire is extended forward, it moves canines and incisors buccally and labially. (C) Active spring moves molars buccally. (D) Active spring moves premolars and other anterior teeth wh~n spring wire is lengthened.

Fig. 21-8. The lingual appliance is activated to correct posterior cross bite. at an angle of 45° and then bend to the desired position. If the auxiliary spring raises the main archwire from its passive position, the auxiliary .spring is exerting too much pressure. It should then be readjusted. 4. When the original spring force has spent itself, the auxiliary springs are again readjusted.

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292 . Appliance Construction and Use

METHODS OF SEP ARA TING TEETH FOR BANDING Soft brass 0.020-inch ligature wire is used to separate molar teeth prior to band fitting. Occasionally separation is required in anterior teeth; an O.OlD-inch steel or brass wire is used. Elastic or steel spring ligatures may also be used (Fig. 21-1). Elastic ligatures of light, medium, or heavy thickness may be used for separating teeth before band fitting, tooth rotations, space closure, tooth alignment and canine retraction, and for bringing teeth into the line of occlusion. The elastic ligature is drawn through the interproximal space of the teeth with a fine ligature wire and tied under tension. Gauges of wires. The following gauges and dimensions of wire are used in labial and lingual appliances: Band material. For banding molars use 0.006-inch or 0.007 X 0.18S-inch or 0.187-inch material. For

anterior band material use 0.003-inch to 0.005 x 0.018Sinch Labial and lingual archwires 0.038-inch to 0.040inch Buccal tubes (round). Usually one-quarter inch in length, to fit various gauges of wires as used. Lock wires - 0.022-inch soft Auxiliary springs - O.OlS-inch or 0.020-inch. Half-round tube length is 0.010 inches, to fit 15gauge, half-round wire Guideplane wire - 0.030-inch Intermaxillary hooks 0.03S-inch

ST AINLESS STEEL APPLIANCES Stainless steel commonly used in orthodontics contains 18 per cent chromium and 8 per cent nickel. This is known as austenetic type steel. Allergic reactions to stainless steel have been found to occur in some patients. Stainless steel used in orthodontics should be malleable, resilient, and impervious to oral fluids; Stainless steel wires when heated to redness and slowly cooled become soft. The temper in stainless steel cannot be restored as in precious metal alloys. Steel wires have a high tensile strength, therefore, wires of smaller dimensions should be used to avoid excessive force. An 0.006-inch steel wire can produce a force of 2S g. While an 0.020-inch steel wire produces a force of almost 700 g. High degrees of force reduce the rate of tooth movement. Initial use of arch wire force should be confined to light round wires of small diameters. Steel wires have a tendency to break under increased manipulation. The wires should be bent slowly if sharp bends are to be made. Soldering Stainless Steel

Fig, 21-10. When stainless steel is soldered, the steel is held close to but not in the flame (top), By winding one piece around the other to which it is to be soldered, a stronger joint is obtained (bottom).

Soldering stainless steel depends on mechanical adaptation, since there is no alloy union or fusion .between the parts soldered. Solder for stainless steel contains potassium fluoride, boric acid, and hydrochloric acid. The solder is melted on the part to be soldered. Low-fusing silver solder and appropriate flux must be used. The parts to be soldered are brought as close to the flame as possible to allow the solder to melt without actually bringing the stainless steel parts to bright redness. A fine needle flame should be used. The soldering operation should be accomplished in one heating, and the soldered joint should immediately be quenched in water. Light wires to be soldered to heavier wires should be wrapped around the heavier wire after soldering. The joint to be soldered should be surrounded by a plentiful supply of flux, and solder should completely cover both sides to be joined. Sufficient heat

Soldering Precious Metals . 293

10. should be applied to just melt the solder; if it is heated too much the soldered joint has a rough, pitted surface. Care should be taken to hold the wires in the exact position desired. High heat should not be used, because it reduces or destroys tensile strength and hardness. The surface of the wires at the site to be soldered should be free of grease and dirt. Soldered joints should not be polished to the extent of removing the outer layer of solder, because it tends to lower the strength of the joint. All flux should be removed but not polished away from a soldered joint. When solder is allowed to flow around one or both of the wires to be joined and the wires are held in proximity, gentle heat is enough to melt the solder and produce a satisfactory joint. When the wires to be soldered are brought near the flame, it should be done slowly to give the flux a chance to dry by gentle heat and to stay in place so as to keep clean the area to be soldered. The area to be soldered should be roughened first with a smooth file or steel brush. The wire is prepared to take the flux evenly and hold it in place. Intermaxillary hooks of stainless steel may be annealed without losing their usefulness. The solder should be melted on the wire used for hooks at some distance from its end and flown onto the archwire. Solder is applied to both sides to be joined and then fused.

Spot Welding Spot welding is accomplished by holding the pieces to be welded together under pressure between hard copper electrodes and passing a high amperage current through them for a given length of time. The electrical resistance of stainless steel is high, so that the temperature generated at the contact causes fusion, and the pressure of the copper electrodes completes the weld. Several welds should be made in welding orthodontic bands. Bracket alignment should be checked and corrected after the initial weld. Welded auxiliary springs should be wrapped around the arch wire.

~~ SOLDERING PRECIOUS METALS Solder of 22 carat is the best for soldering precious metals. Lower carat solders are more brittle. Soldering should be done at the lowest possible temperature. The thinner the space between the wires to be soldered, the stronger the joint will be. Precious metal wires should be softened prior to being shaped. While partially softened wires are less subject to breakage, the bending operations during appliance construction leave highly stressed sections

Fig. 21-11. (Top) A removable appliance with finger springs used to move teeth mesially or distally. The plate has been cut away from the lingual surface of the incisor teeth. A wire has been adapted to help keep the anterior springs in place. When fine wires are used it is better to depend on opening the coil (pushing force) rather than on closure of the coil (pulling force) for tooth movement. The spring is compressed when the coil is tightened. (Center) A retracting spring for moving canine into first premolar extraction space; The free end is flattened and inserted above the mesial contact point. (Courtesy C. P. Adams). (Bottom) A removable plate with springs is used to close a first premolar extraction space.

294 . Appliance Construction and Use

11.

Fig. 21-12. This appliance is used to bring the permanent lateral incisors together in order to obtain space for the erupting lateral incisors and to dose the midline diastema. It is shown below in position in the mouth. that are more likely to break. These are relieved by heat treatment and hardening treatment. THE HAWLEY RETAINER Hawley introduced his retainer in 1919. Biteplanes used for tooth movement produce tipping. The tipping can be minimized and in some cases the root will tend to follow the crown if the force in tooth movement is light. In some instances by moving the crown of one tooth against that of the adjacent tooth and by applying spring force gingivaIly, an inclined tooth can be uprighted. Control of the axial inclination of teeth to be moved is an important con-

sideration when they are moved by means of biteplates. When incisor teeth are in protrusion and change of the position of the root is not required, the biteplate can be used with a flat plane, opening the bite sufficiently to free interlocking cusps, by grinding away the lingual surface of the plate at the maxillary incisors and using a 3fs-inch elastic. Wire springs attached to plates should be cut to size when fitting the appliances in the mouth. The ends of the wire can then be rounded by adding a drop of solder or by turning the end of the spring on itself. Activation of springs for moving teeth should be a little less than half the width of the tooth to be moved. If the appliance is to be used for closing spaces in extraction cases, impressions should be taken first and the appliance constructed before the extractions are performed. Distal movement of premolars can best be obtained by freeing the occlusal surfaces and by opening the bite so that the maxillary and mandibular teeth are slightly out of occlusion. Distal movement of molars can be performed with finger springs attached to a plate. Space closure in the mandible is not easily accomplished with a removable appliance when there is need for bodily movement of the mandibular incisors. While the use of biteplates for tooth movement appears to be easy of accomplishment, retention is important, as is control of axial position of the teeth. Removable appliances require exact knowledge of appliance manipulation as do the fixed appliances. The use of a biteplate to correct excessive overbite frequently meets with failure when the correction of excessive overbite requires changes in the axial relations of the maxillary to the mandibular incisors. This cannot be accomplished easily with biteplates. Biteplates make it possible for the posterior teeth . to become elongated by continuing eruption. Whether the posterior teeth will relapse to their former height after the plate is removed is uncertain. If the masticatory muscles, especially the strong

Fig. 21-13. Tissue surface (left) and side view of mandibular appliance with auxiliary wires to move crowded incisor teeth into alignment.

(right)

The Hawley Retainer' 295 Fig. 21-14. (Top left) Before treatment, the maxillary right central incisor was lost. After treatment (top right) a retaining appliance with tooth attached was fitted (bottom).

Fig. 21-15. Mutilated dentition had caused crossbite (top left). Treatment progressed satisfactorily (center) and cross bite was corrected (rignt). (Bottom) The activator type of appliance was used. It is shown in position in the mouth at right.

masseters, are stretched when the posterior teeth are elongated, there will be a tendency for the vertical dimension to return to its original size. The intrusion of mandibular incisors into the alveolar process will not remain when the plate is removed if the mandibular incisors do not have proper contact and proper angular relation with the maxillary incisors. The maxillarymandibular incisor angle should not be allowed to remain excessively obtuse (over 150°) in deep overbite. If a biteplate or a Hawley retainer is used to retain the mandibular incisor teeth as well, the inclined plane can be constructed in the mouth with quicksetting acrylic. The retainer should then be removed. When the quick-setting acrylic is hardened, it is

trimmed so that the mandibular incisor teeth fit directly against the inclined plane. Among the changes that biteplanes can effect are the following: 1. Forward positioning of the head of the condyle of the mandible; repositioning the mandible, especially in young children when growth is active 2. Opening the bite and diminishing overjet of the anterior teeth 3. Elevation of the posterior teeth; the anterior teeth may be slightly depressed or both changes may occur 4. A more normal anteroposterior relationship of the occlusion 5. Retention after correction of distoclusion

296 . Appliance Construction and Use Fig. 21-16. (Top) Removable appliance for bite opening without a wire retainer. Left, tissue surface. Right, lingual surface. (Second Row) Appliance in position. (Third Row) Left, before treatment. Right, after treatment. (Bottom Row) Left, appliance with a labial wire in position. Right, lingual view of appliance.

6. As an aid in myofunctional therapy 7.Relieve locking of individual teeth or groups of teeth 8. Eliminate tongue habits, lip biting, thumb sucking and other deleterious habits. NOTE. In Class II, Division 2 (Angle) malocclusion the interference of the anterior and other teeth should be removed before the biteplane is used. Biteplanes should not be used where there is a tendency toward an openbite. 9. To retain space when teeth are lost prematurely 10. With additional spring attachments, to move groups and individual teeth 11. For correcting the mesial position of the mandibular teeth in the deciduous dentition.

Bahador and Higley found most of the increase in face height following the use of Hawley-type biteplates to be due to vertical increase in the posterior dental region, mostly in the maxillary posterior teeth. Increase in vertical dimension is accompanied by change also in the mandibular position.

THE REMOVABLE STABILIZING PLATE A removable stabilizing plate was devised by Moyers and Higley that can be used as a means for obtaining anchorage in orthodontic tooth movement in the mixed dentition when all mandibular permanent teeth are not fully erupted. An acrylic plate,

The Removable Stabilizing Plate . 297 Fig. 21-17. (Top and Second Row) Casts show deep overbite

and spacing distal to canine teeth. This young adult patient was not seen before these casts were made. (Third Row) A removable with auxiliary appliance springs was fitted to move canines distally. (The appliance itself is at bottom right.) (Bottom Row) Left, anterior view before treatment. Center, after treatment.

similar to a Hawley retainer, can be constructed for either the maxilla or mandible as required. The plate is constructed to lie in lingual contact with the teeth and to cover as much of the soft tissues lingually as possible. The plate is supplied with wire extensions to which are soldered vertical round or half-round extensions that fit into lingual round or half-round tubes soldered to the molar bands. These are an aid in holding the plate in position. A mandibular plate can be cut away from the lingual surfaces of the incisor teeth, which can then be moved lingually by means of intra maxillary elastics attached to wire extensions on the plate distal to the canine teeth.

Construction 1. Molar bands are constructed with lingual halfround tubes soldered perpendicularly. Intermaxillary hooks are soldered on the buccal surfaces of the bands. 2. Take an impression with the uncemented bands seated on the teeth. 3. Remove the molar bands from the teeth and seat them in their proper position in the impression. 4. Pour the impression in stone. 5.Construct a wire framework and process the plate in quick-setting or blow-on acrylic. A broad, flat acrylic surface contacting the teeth is desirable.

298 . Appliance Construction and Use

Fig. 21-19. (Top) An auxiliary spring of O.028-gauge wire, for lingual movement of a premolar. (Bottom) A lingual spring, O.020-gauge, was used for distal movement of a premolar. Overlying wire guides the activated spring wire. (Adams, C. P.: Removable appliances yesterday and today. Am. J. Orthodont., 55:748, 1969)

7. Polish the plate and insert it in the mouth after the bands are cemented. Fig. 21-18. The Schwarz arrowhead clasp (top) depends on interdental spaces gingival to contact points for retention. The Adams clasp (center) uses mesial and distal undercuts on a single tooth for retention; buccal view of Adams clasp is at bottom. (Adams, C. P.: Removable appliances yesterday and today. Am. J. Orthodont., 55:748,1969)

It is advisable to cover the lingual surface of the molar bands or overlay them with a layer of heavy tinfoil before processing. This facilitates the removal of the band from the acrylic. 6. Remove the molar bands from the plate and cement them in place on the teeth.

ACRYLIC RETAINERS Construction Form the wire attachment according to the type of appliance required. Remove wire attachment from the cast prior to painting the cast with acrylic separating medium. Carefully replace the wire attachment in its proper position and apply acrylic powder and liquid. The wire should be held temporarily in position with sticky wax or other material added on the buccal and the labial surfaces not to be covered by acrylic. Build the palate by alternately applying the acrylic powder and liquid. Work only on relatively small areas, in order to maintain better control over all. Begin construction of the palate by distributing a layer of acrylic powder with the dispensing bottle.

Acrylic Retainers' 299 Fig. 21-20. (Top) The lower traction plate is clasped to four teeth and has hooks on the molar clasps. The labial bow is fitted as near as possible to the incisal edge of the lower incisors. (Bottom) One kind of upper traction appliance is clasped with four clasps and tubes that will take an extraoral attachment which can be added for nighttime use. Figures 21-18 to 20, courtesy (Adams, C. P.: Removable appliances yesterday and today. Am. J. Orthodont., 55:748,1969)

12. Spread the powder evenly. Saturate the powder with acrylic liquid from the dropper bottle. Use liquid generously; too much does no harm, and too little may result in an unsatisfactory bond. Build the area to the desired thickness by repeating the process. The center of the palate is built last because excess lateral material tends to gravitate toward the center. Turn the cast down on its occlusal surface and let it remain in this position for about 15 seconds. This prevents soft material from drifting into the center of the palate. When the material reaches a sticky or tacky stage, turn the cast over and smooth out rough spots with a finger. If the acrylic has set too fast, soften it by adding a few drops of liquid and smooth it over. Allow the appliance to cure on the cast at room temperature for 30 to 45 minutes. This prevents warping and shrinking. NOTE. The acrylic plate may be lifted out of the cast with a knife or any other sharp instrument. Trim and smooth the excess material from the interdental spaces with burs and disks. NOTE. Results are improved if the appliance is soaked in water overnight. This further cures the material and eliminates unpleasant taste.

Repairing Retainers Place the retainer on the original cast or construct

an index so that the retainer lies passive. Clean, trim, and smooth the irregular edges along the break with a bur or stone. Apply acrylic separating medium to the palatal area of the cast and replace the broken parts on the cast. From this point on, the standard procedure is followed by adding quick-setting acrylic until the break is completely filled. When the acrylic is set, trim and polish the retainer.

Fig. 21-21. (Left) Framework for a maxillary stabilizing plate; (center) posterior extension on framework. (Right) Maxillary cast ready for waxing. Note that the posterior extension is covered by stone which holds the framework in its proper relationship. (Courtesy L. B. Higley)

300 . Appliance Construction and Use

~

2

1

Fig. 21-22. Method of applying hooks for intermaxillary elastics: 1, band; 2, fashioned hook; 3, hook soldered on band.

THE EXTRAORAL APPLIANCE Extraoral Appliance Force Malocclusions characterized by forward displacement of the dental arches can be treated with extraoral force emanating from occipital or cervical anchorage. The appliance should be worn 12 to 14

Fig. 21-23. Maxillary stabilizing plate with labial archwire. (Courtesy L. B. Higley)

hours daily during the afternoon, evening, and at night. Some children do not mind wearing it all day. The extraoral appliance must feel comfortable Fig. 21-24. (Top left) Anterior view of casts for which a retainer with inclined plane is to be constructed to prevent a patient from tongue thrusting. The appliance is worn after school, in the evening, and at night. (Top right) With the wire framework and bite, the casts are assembled and joined with sticky wax. (Bottom left> Anterior view showing plaster index over the casts. Petrolatum is applied to the labial and the buccal aspects of the casts before the plaster index is poured. (Bottom right> The lower cast has been removed to show the upper cast, the ends of the wire framework, and the plaster index. The casts are now ready for adding acrylic.

The Exiraoral Appliance' 301 Fig. 21-25. (Left) The lower cast has been replaced and the acrylic biteplate can be constructed. The base of the lower cast has been cut away to permit more direct access when acrylic is applied. (Right) Lower cast has been removed to show the completed plate on the maxillary dental cast.

, Fig. 21-26. (Left) Wire is applied to the maxillary dental cast before "blow-on" acrylic. (Right) The finished Hawley retainer,

to the patient, and the force applied should be in the direction in which the teeth are to be moved. When gentle force is exerted by the appliance the teeth anterior to the molars that carry the appliance will also move distally. A study by Funk on the effect of headgear treatment on the maxillary dental arch showed that mandibular teeth were uprighted and moved distally, mandibular arch form was improved, and tooth rotations were diminished. The most favorable changes produced in treatment with extraoral appliances occur in young patients. The extraoral appliance is useful in some cases as a sale method of treating malocclusion and to reinforce anchorage when intraoral appliances are used.

longer arm of the facebow will receive the greater force. Lateral forces of small magnitude are always developed by an eccentric desgin of the extraoral appliance. These forces can be controlled or manipulated to obtain lateral movement on one side or the other by springing the labial arch inward or outward. Biologic and morphologic variables in the dental arch can cause variation of unilateral or bilateral forces. Molar extrusion should be avoided especially in retrognathic mandibles, since the ietrognathism is increased. The arms of the face bow should not impinge on the cheeks.

Facebow Angulation and Direction of Tooth Movement Asymmetrical Extraoral Appliances force exerted by the extraoral appliance depends on' (1) the point where the force is applied, (2) the magnitude of the force, and (3) the direction in which the force is exerted. When the direction of force from the cervical appliance is asymmetrical because of the difference in length of the facebow arms with respect to the midsagi ttal line of the face, then the anteroposterior components of force on the right and left molars are unequal. The molar nearest the

When the arms of the bow of the headgear appliance are below the occlusal line there is distal tipping of the crowns of the molars. By raising the arms so that they are parallel with the line of occlusion, crown tipping is lessened. In this manner the axial position of molar teeth can be corrected. Distal movement of the teeth anterior to the molars usually follows the molars. The interdental fibers of the periodontal ligament help the distal movement of the buccal series of teeth to move

302 . Appliance Construction and Use Fig. 21-27. (Top) The extraoral headgear assembled. (Bottom) The headgear consists of a section of clothcovered rubber tubing (1). Wire endpieces (2) are connected by a large elastic (3). This appliance follows the design originated by Crain.

Fig. 21-28. A cervical extraoral appliance with extraoral wires of equal lengths moves teeth distally at an equal rate on both sides (left). (Right) The teeth on the side of the longer extraoral wire arm will move faster than those on the side of the shorter arm.

The Extraoral Appliance . 303

6.3 oz.

5.4 oz. 10.5 rom. 4.0 oz. Fig, 21-29, (Top left) Chincap with extension hooks for elastics used for Class nr malocclusion from hooks on the archwire soldered mesial to the molar tubes, (Center) Front view of chincap and headcap to which it is attached. (Right) Profile showing chin cap in position. (Bottom left) The relationship of the face bow to the arch effects the force on the molars. When the face bow is parallel with the arch, the force produces a distal body movement. Bending the face bow below the arch as indicated in the drawing produces a distal crown tipping force upon the molars. (Center) When the face bow is bent above the arch a distal root force is placed on the molars. A distal crown tipping force stimulates faster movement and may open the contact between the molar and the tooth mesial to it. Note, The elastic size is determined by the distance from the end of the face bow and the hooks on the cervical strap, and tissue response, pain being the indication to reduce pressure by using a larger elastic. Constant maximum pressure according to the patient's tolerance is important and desirable according to Kloehn, and can be accomplished by changing elastics several times a week. (After S. J. Kloehn.) (Right) Vector diagram; headgear with spring traction bar.

distally as a unit. When space develops mesial to the molar teeth as distal force is applied, it becomes necessary to move the premolars distally in turn and then to apply force on the incisors to move them distally. Spacing mesial to the molar teeth may be due also to excessive force. Intermaxillary elastics may be used if response to treatment in the permanent dentition is slow when extraoral force alone is used. This is especially useful for lip-biters when the maxillary incisor teeth are pushed forward by the lower lip. Bite opening caused by elongation of molar teeth when using an extraoral force depends on the degree and direction of force applied, the nature of the alveolar bone, and muscle activity. When active, vigorous muscular activity is exerted in chewing

there is a tendency for the elongated molars to return to their original occlusal height. When a biteplate that keeps the jaws apart is used in conjunction with an extraoral appliance, the possibility of elongating the molars is increased. This is not of value in correcting deep overbite, since the vertical height of the molars cannot be arbitrarily permanently increased. The overbite usually is caused by overeruption of the incisor teeth. As the bite is opened there is a tendency for the mandible to assume a more retrognathic rotation in relation to the maxilla. This appears on the cephalometric tracing as a downward and rearward positioning of the mandible. Distal Driving. Extraoral force is a useful aid in inhibiting the forward translation of the dentition

304 . Appliance Construction and Use The patient, preferably, or the parent in younger children, is taught how to place the extraoral appliance into position. Construction

Fig. 21-30. (Top) A "high pull" extraoral appliance in position; (bottom) a cervical extraoral appliance in position. and to help stabilize anchorage when Class II intermaxillary elastics are used. So-called distal driving of the maxillary dental arch serves to inhibit the forward translation of the dental arch and has been found to modify the vector of growth of the maxilla in general. The extraoral appliance can be used in the mandible in Class III fashion by moving the mandibular molars distally and for providing space for the teeth anterior to the molars. Shifting of permanent molars caused by premature loss of deciduous molars, with encroachment on the premolar eruption space, can be prevented with the extraoral appliance. When dental arch-basal arch discrepancy is slight, it is possible by means of extraoral force to move the buccal segments distalIy and frequently to avoid extraction, especially if treatment is initiated in the early mixed dentition. When using force emanating from occipital anchorage, it is necessary to guard against impaction of third and possibly second molars, if the first molars are tipped too far distally. Additional appliances are usualIy needed to complete tooth positioning and rotations.

Cement molar bands onto the deciduous second molars. If these teeth are missing or if their roots show advanced resorption place the bands on the permanent first molars. Solder tubes with 0.040 or 0.045-inch inside diameter, and attach rectangular tubes to hold an 0.020inch archwire to be attached to the bracketbands on the teeth, as far gingivally and mesialIy as possible, for distal tooth movement. The labial arch wire should lie opposite the gingival level of the incisor teeth. The molar tubes can be adjusted to permit root or crown tipping of the molars when desired. The labial archwire is constructed of 0.040-inch or 0.045-inch stainless steel. wire. Soldered or welded fixed stops are attached to the arch wire to rest against the mesial ends of the molar tubes, while the arch rests labially 0.25 inch away from the incisor teeth. A 0.040inch spur to receive the traction bar or face bow is soldered to the labial archwire at the median line. The face bow or traction bar itself also may be soldered to the archwire itself. Stops are soldered on the 0.045-inch labial archwire so that its anterior part is 4 to 5 mm. away from the incisors. The labial arch may be allowed to rest against the incisors if it is desired to move the incisors lingually, in which case the stops are placed on the arch wire away from the anterior limits of the molar tubes so that the archwire can slide into the tubes as the incisor teeth are brought lingualIy. When the incisor axial relation is corrected the stops are replaced on the arch wire to rest against the molar tubes to move the molar teeth distally. Another method of moving incisor teeth lingually is to attach hooks on the archwire of the extraoral appliance distal to the canines and to attach 3fsinch rubber dam elastics that would exert pressure on the incisors. The mesiobuccal cusps of the maxillary first molars can be rotated buccally by bending the ends of the labial arch buccally in front of the molar tubes. The traction bar or face bow of 0.070-inch round wire is constructed with hooked ends to hold the cervical gear. The cervical gear is made of 1.5-inch wide belting material.

JUMPING THE BITE What is known as "jumping the bite" is accomplished by an abrupt change in the position of the mandible produced by orthodontic means. This may

Teeth Protectors . 305 be accomplished with strong elastic force, by incorrect use of the activator appliance, and by stops attached to the teeth that make it impossible to bring them into full occlusion without bringing the mandible forward. The adult temporomandibular articulation does not adapt itself as a rule to "jumping the bite." Orthodontic bite jumping especially in the permanent dentition can result in the establishment of a "dual bite." The method may be erroneously considered successful where the patient had a dual bite before treatment. This is a bite in which the patient brings the mandible forward voluntarily but occludes distally in a Class II relation when the teeth are brought together involuntarily. Successful cases of bite jumping in adults can be attributed to repositioning of the body of the mandible. In early childhood a change in the vector of growth of the mandibular condyle is possible, since the condyle and subcondylar portion of the ramus do not calcify until late adolescence.

SLIDING JIGS In constructing a sliding jig, an 0.020- or 0.022inch round steel wire is used. The use of the sliding jig in conjunction with intermaxillary elastics makes possible the distal movement of teeth in series. The jig can be activated against the tube on the band of the last molar or tied to any of the teeth anteriorly. It is best to construct the jig so that the anterior hooked loop is situated just distal to the canine bracket. As space is opened, the jig is engaged anteriorly to the canine bracket so that the canine is activated in a distal direction. The use of the sliding jig permits serial movement of the teeth distally from the canines. It permits using the entire mandibular arch as stationary anchorage against two teeth at a time, one on each side of the maxillary jaw, or to move teeth on one side of the dental arch distally. Sliding jigs for space closure after extraction of premolar teeth may be used with the headgear to make certain that the molars will not move forward if forward movement of molars is not desired. When maxillary molars are moved distally by means of sliding jigs, the premolars will usually be found to move distally at the same time. This is true especially in children who swallow in the normal closed-mouth manner. In the tongue-thrust or open-mouth swallow when the tongue rests habitually on the occlusal surfaces, the premolars do not usually move distally with the molars. The required direct force can be achieved by tying the sliding jigs directly to the premolars and then to the canines. The use of lighter elastics is beneficial in maintaining anchorage stability. When anchorage stability is lost, it can be regained by discontinuing

Fig. 21-31. (Top) Intermaxillary hooks for attaching extraoral appliance and for inter- or intramaxillary elastics. (Second row) Sliding jig used against molar tube to drive the molar distally. The premolar teeth usually move distally with the molars. (Third row) Sliding jig used in front of the canine tooth to move it distally. (Bottom) Use of a Pletcher coil to retract the maxillary canine tooth.

distal movement of the teeth for about 6 weeks, until the teeth are again stabilized in the alveolar process. TEETH PROTECTORS Fixed orthodontic appliances need not be removed in order to construct a teeth protector. The impression is made with the fixed orthodontic appliance in place and the teeth protector is constructed to fit over the appliance. To construct a teeth protector alginate impressions of the dental arches and a wax bite with the teeth about 3 mm. apart are taken, and the casts are poured.

306 . Appliance Construction and Use Teeth protectors should meet the following requirements: (1) occupy as little space in the mouth as possible; (2) be light and easily positioned on and removed from the teeth; (3) do not impinge on the soft tissues; and (4) do not distort the muscles of the face to any great degree. Teeth protectors may be made of prefabricated rubber with a thermoplastic lining, or of latex, clear acrylic, or semihard acrylic shell with a soft acrylic insert. A material of silicon vinyl in clear plastic 0.125 inch thick is available in 3" X 6" sheets. The material is soft and flexible and is readily formed by softening in heat and molding on a dental cast. The teeth protector is trimmed to about the middle of the crowns of the teeth. A second layer can be added to the first by heating the surface of the layers.

BIBLIOGRAPHY Adams, C. P,: The Design and Construction of Removable Orthodontic Appliances. Bristol, John Wright & Sons, 1955, --_: The design of removable appliances for intermaxillary and extra-oral traction. D. Practitioner, 5:244, 1955. --_: The design of removable appliances for mesial movement of teeth. D. Practitioner, 6:191, 1955. --_: Removable appliances yesterday and today. Am. J. Orthodontics, 55:748,1969. Andresen, V.: Ein gnatho- physiognometrisches System als asthetische Grundlage der biomechanischen Orthodontie. Fortschr. Orthod, Vol. 4. 1932. --_: Die Gnathophoremethode die ktinstlerische Diagnose und wissenschaftliche gnathophysiognomische Diagnose. Fortschr. Orthod. Leipzig. Hermann Meusser, 1936. -_: Gnathologische und physiognometrische Proportionslehre als diagnostische Grundlage der Punktionskieferorthopadie, Den. norske Tand. Tid, 3: 1938. Bahador, M. A and Higley, 1. B.: Bite opening: A cephalometric analysis. J.AD.A., 31:343,1944. Baldridge, J. P.: Unilateral action with headcap. Angle Orthodontist, 31 :63, 1961. Bayne, D. I.: A preliminary study of changes in the lower arch subsequent to cervical force treatment in the maxillary arch (Abstract). Am. J. Orthodontics, 46:386, 1960. Bell, W.: A study of applied force as related to the use of elastics and coil springs. Angle Orthodontist, 21 :151, 1951.

Beresford, J. 5.: Orthodontic springs for removable appliances. D. Practitioner, 2:178,1951. Block, A J.: Headgear- modifications and admonitions. Angle Orthodontist, 32:19, 1962. Brock, W. C.; 'The principle of coil spring traction applied to cervical strap therapy. Am. J. Orthodontics, 46:43, 1960. Brodie, A G.: Technique of the pinch-band. AngleOrthodentist, 2:260, 1932. ___ : A discussion of torque force. Angle Orthodontist, 3:263, 1933. --_: The application of the principles of the edgewise arch in the treatment of Class II division 1 malocclusion. Angle Orthodontist, 7:3, 1937. Brousseau, ]. c.: Bilateral Class II division 1 malocclusion treated with an occlusal gUide plane. Am. ]. Orthodontist, 38:444, 1954. Hawley, C. A.: The principles and art of retention. D. Record, 44:175, 1924. Holdaway, R. A.: Bracket angulation as applied to the edgewise appliance. Angle Orthodontist, 22:227, 1952, Hopkin, G. B.: A case of cutaneous sensitivity to stainless steel. Brit. D. L 98:117,1954. Hopkins, S. c.: Inadequacy of mandibular anchorage. Am. ]. Orthodontics, 41 :691, 1955. --_: Inadequacy of mandibular anchorage-five years later. Am. ]. Orthodontics, 46:440, 1960. Lewis, P. D.: Principles for use of the edgewise bracket with rotation arms. Angle Orthodontist, 29:182, 1959. McKeag, H. J. A: The teaching of appliance design in orthodontia. D. Recoral, 56:260, 1936. Mershon, J. V.: The removable lingual arch as an appliance for the treatment of malocclusion of the teeth. Int. J. Orthodontics, 4:578, 1918. --_: The removable lingual arch and its relation to the orthodontic problem. Dental Cosmos, 62:693, 1920. - __ : A practical talk on why the lingual arch is applicable to the orthodontic problem. D. Record. 46:297, 1926. The removable lingual arch appliance. Int. ]. Orthod., Oral Surg. & Radiog., 12:1002, 1926. Moyers, R. E. and Higley, 1. B.: The stabilizing plate, an adjunct to orthodontic therapy. 35:54, 1949. 'PosseH, U,: Bite guards, bite plates, and orthodontic treatment in periodontal disease. D. Practitioner, 11 :126, 1960. Rortsahl. ].: Zum Problem der sagittalen Beeinfliissung der oberen apikalen Basis mit Platten beim umgekehrten Frontzahniiberbiss. Fortschr. Kieferorthop, 23:312, 1962. Salzmann, J. A: The use of removable appliances. Am. ]. Orthodontics, 51 :865, 1965.

22 Diagnosis and Treatment in the Deciduous Dentition TYPES OF NORMAL OCCLUSION IN THE DECIDUOUS DENTITION

deciduous second molars are on the same vertical plane. 2. Deciduous molars follow the same relationships as in normal occlusion of permanent molars, the mesiobuccal cusp of the maxillary deciduous second molar occluding into the buccal groove of the mandibular deciduous second molar. The deciduous second molar relationship is not an invariable base for classification in the deciduous dentition, since the foregoing two types are both considered normal. The canine relationship should

Patterns of occlusion in the deciduous dentition that may be regarded as normal are the following: 1. Distal surfaces of the maxillary and mandibular

A

B

Fig. 22-1. These drawings illustrate changes in premolar-molar relationship with the change from the mixed to the permanent dentition. (A) Top group shows occlusal relation before loss of the deciduous second molars. The middle group shows the relation after the deciduous second molars are lost; the mandibular permanent first molar (6) has shifted forward. The bottom group shows the final relationship under normal occlusal adjustment. (B) The middle and bottom groups show prolonged retention of the mandibular deciduous molar interfering with the premolar-molar adjustment, initiating a forward relationship of the maxillary arch. (After A. Kantorowicz)

Fig. 22-2. The entire deciduous dentition has erupted, and permanent incisor teeth are developing. There is interdental spacing in the deciduous dentition. The erupting permanent incisor teeth are crowded.

30 7

308 . Diagnosis and Treatment in the Deciduous Dentition

Fig. 12-3. (Top) The maxillary deciduous dentition has erupted and permanent incisor teeth are calcifying. (Bottom) Mandibular deciduous teeth have erupted, and the permanent incisor teeth are calcifying. There is no interdental spacing in the deciduous incisor area as in Fig. 22-2. The developing permanent incisor teeth nevertheless show less crowding than those in Figure 22-2. Deciduous teeth do not become spaced. They erupt either spaced or in close contact. be employed in diagnosing mesiodistal arch malrelation in the deciduous dentition. In normal dental development the permanent first molars usually complete their eruption at age 6 to 7 years and assume their normal relationship, in which the mesiobuccal cusp of the maxillary permanent first molar occludes within the buccal groove of the mandibular permanent first molar and the mesiolingual cusp occludes at the occlusal fossa of the mandibular first molar. The permanent molar oc.ciusal adjustment occurs while the premolars are erupting. If the occlusal adjustment does not occur, there is a distal relation of the molars and frequently malocclusion of the entire interarch relation.

DECIDUOUS DENTITION AS AN INDICATOR OF A NORMAL PERMANENT DENTITION The normality of occlusion in the permanent

Fig. 22-4. (Left) Crossbite in deciduous dentition. The maxillary left deciduous central incisor tooth was lost in an accident. (Right) The dentition after orthodontic therapy. dentition cannot be predicted on the quality of the occlusion of the deciduous teeth. Likewise, the size of the deciduous teeth is not an indicator of the size of the permanent teeth. Interception of malocclusal tendencies and correction in the deciduous or mixed dentition do not necessarily prevent malocclusion in the permanent dentition. More than one period of orthodontic treatment may be necessary. While interceptive orthodontic measures must be applied early in the life of the child, corrective

Indications for Treatment in the Deciduous Den~ihon . 309 Fig. 22-5. (Left) At 7'h years the central incisors are separated. This patient had no orthodontic treatment, and at 10 years (right) the central incisors had come together and the laterals had erupted. Treatment, if necessary, will be initiated in the permanent dentition.

orthodontic therapy may be instituted at any age when a condition is found to interfere with the continuing normal development and function of the dentition. Periodic examinations are especially advisable during the early stages of the mixed dentition.

INDICATIONS FOR TREATMENT IN THE DECIDUOUS DENTITION Treatment in the deciduous dentition should be instituted when the roots of the deciduous teeth reach their terminal stage of development and before root resorption has progressed to a point where the teeth can be easily dislodged. Mathews found that the position of permanent teeth can be influenced favorably by changing the position of the overlying deciduous teeth, as long as there is

sufficient root structure to permit banding the deciduous teeth. , Complicated appliances should be avoided in the deciduous dentition. Treatment should concern itself primarily with functional interferences and the continuing normal development of the dental arches. Severe anomalies affecting groups of teeth, the face, and the relationship of the jaws to each other and to the cranium should be treated. All obstacles to tooth eruption, such as odontomas, supernumerary teeth, cysts, etc., should be removed as early as possible so as not to interfere with the eruption of the teeth. Indications for treatment in the deciduous dentition may be summarized as follows: 1. Gross interferences with the establishment of normal occlusion 2. Loss or impairment of function

Indications for Treatment in the Deciduous Dentition' 309 Fig. 22-5. (Left) At 7lf2 years the central incisors are separated. This patient had no orthodontic treatment, and at 10 years (right) the central incisors had come together and the laterals had erupted. Treatment, if necessary, will be initiated in the permanent dentition.

orthodontic therapy may be instituted at any age when a condition is found to interfere with the continuing normal development and function of the dentition. Periodic examinations are especially advisable during the early stages of the mixed dentition.

INDICATIONS FOR TREATMENT IN THE DECIDUOUS DENTITION Treatment in the deciduous dentition should be instituted when the roots of the deciduous teeth reach their terminal stage of development and before root resorption has progressed to a point where the teeth can be easily dislodged. Mathews found that the position of permanent teeth can be influenced favorably by changing the position of the overlying deciduous teeth, as long as there is

sufficient root structure to permit banding the deciduous teeth. , Complicated appliances should be avoided in the deciduous dentition. Treatment should concern itself primarily with functional interferences and the continuing normal development of the dental arches. Severe anomalies affecting groups of teeth, the face, and the relationship of the jaws to each other and to the cranium should be treated. All obstacles to tooth eruption, such as odontomas, supernumerary teeth, cysts, etc., should be removed as early as possible so as not to interfere with the eruption of the teeth. Indications for treatment in the deciduous dentition may be summarized as follows: 1. Gross interferences with the establishment of normal occlusion 2. Loss or impairment of function

310 . Diagnosis and Treatment in the Deciduous Dentition TIMING OF OCCLUSAL GUIDANCE Timing of occlusal guidance procedures should be based on serial examinations that include cephalometric, lateraljaw, and intraoral radiograms, and dental casts. The time to start corrective treatment depends on the presence of a condition which interferes with the continued normal development and function of the dentition, regardless of chronologie age of the patient. Diagnostic records should be obtained during the following dentofacial development stages: 1. Before the permanent molars and incisors begin to erupt. 2. After the permanent first molars and incisors are fully erupted. 3. Before any orthodontic treatment is started. Malocclusion in the young child is usually progressive. Consideration should be given to maturative, physiologic, and dental developmental ages. These do not always coincide or progress at the same rate even in the normal child. Chronologie age varies in the individual child but bears a positive correlation to the number of erupted permanent teeth, root calcification, and bone age.

ESTIMATES OF DENTAL AGE IN THE DECIDUOUS DENTITION Fig. 22-6. Before (left) and after (right) casts of crossbite that was corrected during late deciduous dentition. A removable mandibular appliance was used that had a flange to guide the maxillary dentition into alignment (bottom).

3. Incipient dental malocclusion and jaw malposition 4. Class I (Angle) malocclusion, when the maxillary incisors occlude lingual to the mandibular incisors 5. Class II, Division 1 malocclusion, when severe enough to affect jaw relation in addition to dental arch relationshi p 6. Class II, Division 2 malocclusion with severe jaw malrelation and overbite injurious to maxillary mucosa -" 7. Class III malocclusion (should be treated early before root resorption begins in the deciduous mandibular incisors)

Three related estimates of dental age are available in the deciduous dentition: (1) the number and the type of erupted teeth present in the mouth; (2) the rate of calcification of the permanent mandibular first molars; (3) the rate of calcification of the dentition as a whole, in relation to standards of growth. EARLY TREATMENT IN CLASS III MALOCCLUSION Because Class III malocclusion becomes progressively worse during growth, early treatment is advocated. The force of occlusion exerted by the lingually occluding maxillary incisor teeth on the growing mandible is accepted as tending to encourage its forward progress. Early treatment can influence thevectorof growth of the bodyof the mandible. THE CHINCAP

CONTRAINDICATIONS TO TREATMENT IN THE DECIDUOUS DENTITION 1. Patient unwilling to cooperate in treatment 2. Poor prognosis

The chincap was used by Cellier (1802) and by Fox early in the 19th century. Tomes described it in 1873. Victor Hugo Jackson (1890) used it. Angle, Case, and Oppenheim used the chincap early in this century. Forward growth of the mandible can be inhibited when the chincap is used. Maxillary growth can then

13.

The Chincap . 311

Fig. 22-7. Treatment of this patient's Class III malocclusion began when she was 3112 years old. Compare her appearance before (A, B) and after (C)

treatment. A chincap (D, E) was worn and a Ii ngual appliance were used (F, G, H). The front view (f) shows the 3/B-inch elastic ligature in place. Note that the anterior portion of the lingual archwire is away from the front teeth (G). A side view of the appliance shows buccal extensions and hooks for the elastic. Frontal views show the occlusion before (1), during (j), and after (K) trea trnent.

(Continued on overleaf)

be expected to overcome the disproportion in forward growth. The chincap should not be used in the attempt to retract the mandible but to exert a

holding effect. It should fit snugly but should not exert appreciable pressure. It is of value primarily during the active growth period in the young child.

312 . Diagnosis and Treatment in the Deciduous Dentition Fig. 22-7 Continued (L) Another patient, age 4, anterior view. (M) Dentition before treatment. (N) Appliance in position with latex ligature moving the mandibular incisors lingually. (0) Anterior view after treatment.

Changes produced by the chincap can be compared to the skull changes brought about by certain South American Indians who flattened the heads of children, producing deformities of the cranium. The changes produced occur in the vector of growth but not as a result of inhibition of growth. Gentle pressure on the chincap should be directed in a backward rather than an upward direction. Pressure against the temporomandibular articulation should not be directed for the purpose of inducing changes in the glenoid fossa. Armstrong found young children with Class III dental incisor relation to show an appreciable improvement when the chincap is used. The changes in the incisor region when the chincap is used are lingual inclination of incisor teeth. The chirrcap should be worn 12 to 14 hours a day. Oppenheim was the first to use force to move maxillary teeth mesially by means of extensions from a chincap to which intermaxillary elastics are attached.

Use of the Chincap for Developing Class III Malocclusion The chincap is not intended to push the mandible rearward but rather to inhibit its forward growth. At the same time the maxilla is left unhampered to continue forward growth. As shown by Baume, the condyle is responsive to mechanical force. The chincap does not inhibit forward growth of the jaw. It

14.

changes the vector of mandibular growth. The claim that chincaps will not affect the vector of growth of the mandible is inaccurate in view of the changes in the cranium seen in primitive tribes who compress and deform it.

INDICATIONS FOR DECIDUOUS TOOTH EXTRACTION Indications for extraction of prolonged retained deciduous teeth are as follows: 1. The root is resorbed while the cervix of the crown is attached to the alveolar mucosa and interferes with the eruption of the permanent successor. 2. The permanent tooth is ready to erupt as indicated by the degree of completion of its roots and its proximity to the alveolar bone crest, and the deciduous tooth shows little or no root resorption. 3. A permanent tooth is erupting through the buccal alveolar mucosa before the deciduous tooth is shed.

4. The roots of a deciduous molar are resorbed, and the succeeding premolar shows calcification of onehalf to two-thirds of its root; there is no overlying alveolar bone; and the premolar on the opposite side of the dental arch has erupted. S. The permanent first molar has erupted past the deciduous second molar occlusally and there is wedging of the deciduous second molar into the

Indications for Deciduous Tooth Extraction' 313 Fig. 22-8. (A) J\nterior views of patient with mandibular dental prognathism in the late deciduous dentition. (Center left) (B) Views with chincap in position. right. (Upper right) Mandibular dental prognathism is eliminated. (e) Lateral view at start of use of chincap. (OJ Lateral view showing profile at age 12 years with permanent dentition erupted.

alveolar process. The deciduous second molar should be extracted and the space retained. Extraction of the deciduous molars should be followed by

periodic checking to assure proper eruption space for the premolars. In the absence of a permanent tooth follicle where

314 . Diagnosis and Treatment in the Deciduous Dentition the dentition shows crowding and there is jaw length deficiency, in relation to obtaining normal dental arch arrangement, consideration should be given to extraction of the deciduous tooth and closing the space. The patient should be kept under supervision to prevent unfavorable tooth shifting. Orthodontic intervention usually is required in the permanent dentition in these cases.

PREMATURE LOSS OF DECIDUOUS TEETH Premature loss of deciduous teeth can be responsible for the development of malocclusion of the permanent dentition, although the premature loss of deciduous teeth is not a factor in jaw growth itself. The deciduous teeth affect the vertical and

horizontal positioning of the permanent teeth. Thus, they help to maintain the line of occlusion and the mesiodistal arrangement of the dental arches. Shifting of teeth following premature loss occurs in the deciduous and mixed dentitions. The continuity of the dental arch can thus be destroyed and the arrangement and symmetry of the dental arches endangered. The resulting harm to the later erupting permanent dentition depends, among other factors, on the length of time elapsed before the permanent succeeding teeth erupt. Premature loss of deciduous first or second molars is not necessarily always followed by space closure and malocclusion. The space left by loss of deciduous molars may close: it may remain stationary; or it may become larger. Early loss of mandibular deciduous molars is more frequent than the loss of maxillary deciduous molars. Spaces should be measured at successive time intervals. If evidence of closure is found; space maintainers or a holding lingual arch appliance should be employed. If the deciduous

Fig. 22-9. (Left) The deciduous second molar is interfering with the eruption of the first and second premolars. (Right) An over-contoured filling is causing occlusal trauma evidenced in the widened periodontal ligament of the premolar teeth that shifted.

Fig. 22-10. (Top) Radiograms show over-retention of deciduous second molar crowns in the maxilla. This can lead to interference with occlusal adjustment in the mixed dentition. (Bottom) In the mandibular radiograms the deciduous second molar crowns are retained in position by their attachment to the gingival mucosa. Deciduous tooth crowns should be extracted when it becomes evident that they are interfering with the eruption of their permanent successors.

Fig. 22-11. (Top) Alveolar bone overlies the crown of the second premolar, which still has to complete calcification. The deciduous second molar shows root resorption but should be retained in position until the premolar is ready to erupt. (Bottom) Early loss of the deciduous second molar has hastened the eruption of the premolar before it actually had sufficient root formation.

Effect of Sequence of Tooth Eruption on the Deciduous Dentition' 315 molars are lost prematurely and the space closes only 1 or 2 mrn., there may still be sufficient space to accommodate the succeeding premolar teeth, provided they are not larger, mesiodistally. than the deciduous molars. In children with well-developed arches there is, as a rule, little closure of the space after the deciduous molars are lost. Premature loss of maxillary deciduous incisors seldom affects permanent incisor eruption and tooth arrangement. In prematurely lost deciduous canines, at or after the eruption of the permanent incisors, the space usually closes, interfering with the erupion of the permanent canines.

EFFECT OF SEQUENCE OF TOOTH ERUPTIO o THE DECIDUOUS DENTITIO The order of tooth eruption can affect the occlusion of the permanent canine, depending on the amount

Fig. 22-12. (Top) The maxillary permanent first molar is impeded in its eruption because it is caught within the deciduous second molar. (Bottom) Three years later, the permanent first and second molars have erupted. The space for the second premolar is closed and the second premolar is impacted. Freeing the permanent molar from the second deciduous molar and space retention could have prevented this malocclusion.

Fig. 22-13. Supernumerary teeth interfere with eruption of maxillary central incisor teeth. The permanent lateral incisors are erupted, while the deciduous central incisors are still in position. The cause of delayed eruption and eruption out of the usual sequence should be investigated.

Fig. 22-14. (Top) An overretained deciduous second molar caused ectopic eruption of the second premolar. Roots of the deciduous second molar are resorbed, and its crown is retained by attachment to the alveolar mucosa. (Bottom) Uneven resorption of the roots of the deciduous second molar caused ectopic eruption of the second premolar. Deciduous teeth should be extracted when it is evident that they interfere with the eruption of permanent teeth.

316 . Diagnosis and Treatment in the Deciduous Dentition of space closure. The permanent canine usually is crowded out of the arch if it erupts after the premolars. If the maxillary deciduous second molar is lost before the permanent first molar erupts, the space for the second premolar is usually reduced by the forward shifting of the erupting permanent first molar. Premature loss of mandibular deciduous second molars may occur before the permanent first molar erupts. Placement of a space retainer should be postponed until the permanent first molar begins to erupt. Insertion of spurs through the mucous membrane against the unerupted molar may actually interfere with its eruption, and infection may infiltrate through the opening in the mucosa. Infected deciduous teeth should not be retained in the mouth for the purpose of maintaining space. Space maintainers should be inserted when necessary. Permanent teeth lost through caries must be replaced in children just as readily as in adults if malocclusion is to be avoided. Ankylosed deciduous teeth should be extracted when the permanent succeeding teeth show about one-half of their roots to be calcified. If a deciduous ankylosed tooth has no permanent s.uccessor it can be extracted and the space closed, if such treatment is indicated by the general state of the occlusion and jaw growth. Space closure in the mandibuler dental arch when a second premolar is absent may leave the opposing third molar in the maxillary dental arch without an occluding opponent. A large alveolar arch and agenesis of some of the teeth in the same arch contraindicate space closure. Resorption of ankylosed deciduous teeth roots may be partial or it may not occur. Root resorption in deciduous teeth without permanent successors occurs more frequently when the deciduous teeth are filled and when their occlusal plane is not below the general line of occlusion of the teeth.

DIASTEMAS IN THE DECIDUOUS DENTITION Two distinct diastemata can be observed in the deciduous dentition-one between the mandibular deciduous canine and the first molar and the second between the maxillary lateral deciduous incisqr and the deciduous canine. There is no evidence of a continuously increasing dimension at intercanine and intermolar width or appreciable growth in the completed deciduous dentition. Vertical and horizontal growth of the alveolar processes is concomitant with the development of the permanent teeth. There is vertical, horizontal, lateral growth of the jaws, but no shifting of the deciduous dentition as a unit.

SPACING OF TEETH Spacing of the teeth in the deciduous dental arches depends on the extent of growth of the jaws and alveolar process, the size of the teeth, the size of the tongue, and the tonicity of the circumoral musculature. Locking of permanent first molars against the deciduous second molar is usually associated with general lack of growth of the basal arches of the jawbones and with general tooth crowding. Locked permanent first molars may resorb the second deciduous molar at the cervical portion of the tooth. The distal root may be severed and become imbedded in the alveolar process. The permanent molar crown, when caught at the gingival margin of the deciduous second molar, can be freed by disking the distal surface of the deciduous second molar crown. If root resorption in the deciduous second molar is advanced, the tooth should be extracted and a space maintainer should be inserted until the second premolar shows eruption. Separation of slightly locked permanent first molars can be effected by passing a wire or elastic dental floss ligature through the interdental space. When a wire is used it should be twisted at intervals until separation of the teeth is obtained. Grinding of incisal tips of deciduous canines is useful to permit free lateral excursion of the mandible, to prevent interference with forward movement of the mandible, and to correct crossbite in the deciduous and early mixed dentitions.

CROSSBITE Crossbite tends to appear when the deci.duous canine teeth erupt- between the ages of 18 months and 2 years. The canines may show cusp-to-cusp relationship while the mandible slides to the left, 'right, or forward. Crossbite should be treated in all classifications of malocclusion before the attempt is made to correct mesiodistal arch malrelation, Crossbite may be confined to the teeth alone or it may involve the alveolar process and the jaws. Lingually occluding maxillary incisors and labially occluding mandibular incisors should be treated in relation to available space and arch development. The position and shape of the temporomandibular articulation and the form of the glenoid fossa can be affected by the deviation of the mandible, if the crossbite brings the jaw out of centric relation when the teeth are occluded. Appliances such as modified activators may be used when treating crossbite in the deciduous dentition as early as age 3 to 5 years. In the mixed denti-

Crossbite . 317 Fig. 22-15. (A) The pattern of eruption, at 7 years, shows separation of the permanent maxillary central incisors and insufficient space for erupting permanent lateral incisors, Treatment of malocclusion is not warranted at this time, because natural growth may overcome deficiencies of this type, An occlusal view (C) shows the maxillary left permanent first molar to be caught on the distal bulge of the crown of the second deciduous molar. Casts made at age 9 show persistence of the early eruptive pattern and lack of development in the maxillary incisor region (B), In the occlusal view it can be seen that (D) the maxillary left deciduous second molar was shed and the space was partially closed by forward shifting of the first molar. The radiogram shows the maxillary permanent first molar caught on the partially resorbed crown of the deciduous second molar (EJ. Space closure occurs after early loss of deciduous teeth because the remaining teeth shift. Often, closure is pathognomonic of a constricted basal arch pattern rather than a lack of growth induced by loss of a tooth. Basal arch growth in the respective bodies of the jaws is independent of the presence or absence of teeth.

han, removable appliances are indicated that will not interfere with the natural eruptive process and establishment of the occlusion of the permanent teeth. In posterior cross bites in the permanent molars, cross ~lastics may not prove efficient. While normal

tooth alignment may be achieved in this manner the position of the body of the mandible may remain in lateral deviation. Therefore, mandibular repositioning may be required prior to crossbite correction. An activator appliance can be used for this purpose.

318 . Diagnosis and Treatment in the Deciduous Dentition the distance on the casts from the palatine midline to the teeth on both sides of the dental arch.

THUMB AND FINGER SUCKING Infantile thumb sucking and other nonnutritive sucking habits are significantly correlated to malocclusion of both the deciduous and permanent teeth. In order for sucking pressure to affect occlusion, the force exerted has to be stronger than the component of force that the alveolar and facial bones can withstand. If this were not so, the face of man would be in a constant state of startling change, like the face of an elastic toy that changes grotesquely on the application of slight pressure. Circumstances that affect the extent of change that pressure habits can induce in the orofacial region depend on the frequency with which the habit is practiced, the duration of time that the habit has lasted, the osteogenic development, the genetic endowment, and the general state of health of the child. These determine the presence, type, and severity of the resulting malocclusion. NAILBITING

Fig. 22-16. (Top) The maxillary permanent first molar is erupting against the deciduous second molar. (Center) The permanent first molar causes resorption on the deciduous second molar crown and can cause it to be shed prematurely. Another result may be impaction of the unerupted second premolar. (Bottom) The deciduous second premolar is disked to allow the permanent molar to erupt past the distal bulge of the deciduous molar crown.

Posteroanterior cephalograms and dental casts can aid in determining whether the fault of the cross bite is caused by alveolar and dental deviation in the maxillary arch, the mandibular arch, or both arches. This can be ascertained in the maxilla by measuring

Nailbiting is most commonly seen in tense, excitable children, in contrast to thumb sucking, which is more likely to occur in children who are outwardly calm and placid. N ailbiting of the fingers occasionally is associated with biting the toenails and with picking at the nails with the fingers. Some nailbiting of a transitory nature, frequently in imitation of other children, is observed in early adolescence. Arousing a new interest in the fingernails such as the application of fingernail polish has been found helpful in girls. Boys may be appealed to on the basis of good sportsmanship or reward for effort in sparing the nails of an increasing number of fingers. , Lip biting may be treated by attaching labial acrylic plumpers to a fixed or removable appliance on the mandibular dental arch. Use of mechanical devices should be discouraged in the preschool child. The thumb should not be pulled forcefully out of the infant's mouth. There should not be a show of disapproval or punishment nor ridiculing, criticism, or shaming the child. Parents should be advised to observe the following principles: 1. Promote favorable relation of the child with his immediate environment. 2. Provide play materials suited to the child's stage of development. 3. Provide the child with opportunity and space to be active, to experiment, to explore, and to play.

Bibliography . 319 4. Reduce supervision of the child to necessities, and provide as much freedom as possible. 5. The attitude toward the child should be one of happiness, sympathy, patience, and understanding.

BIBLIOGRAPHY Altemus, L. A.: Relationships of tooth material and supporting bone, D. Progress, 1:36, 1960, Armstrong, C J.: A Clinical Evaluation of the Chin-Cup. Australian D. J., 6:338, 1961Baker, C R.: The selection of cases for treatment in the deciduous dentition. Am. J. Orthodontics, 39:273, 1953. Brock, J. R.: The role of the speech clinician in determining indications for frenulotomy in cases of ankyloglossia. New York State D.J., 34:479, 1968. Bogue, E. A.: Orthodontia of the deciduous teeth. D. Digest., 18:671, 1912; 19:9, 1913; 25:193, 1919. Breitner, C, and Tischler, M.: Ueber die Beeinflussung dey Zahnkeime durch orthodontische Bewegung der Milchzahne. Ztschr. Stornatol., 32:1383, 1934. Breitner, c.: The influence of moving deciduous teeth on the permanent successors. Am. J. Orthodontics, 26:1152, 1940. - __ : The tooth-supporting apparatus under occlusal changes. J. Periodont., 13:72, 1942. Clinch, L. M.: A longitudinal study of the results of premature extraction of deciduous teeth between 3-4 and 13-14 years of age. D. Practitioner, 9:109,1959. Jamison, H. C: Prevalence of periodontal disease in the deciduous teeth. J.A.D.A., 66:207, 1963. Leighton, B. C: Serial models illustrating some spontaneous changes in the deciduous dentition. D. Practitioner, 11:109,1960. Linder-Aronson, S.: The effect of premature loss of deciduous teeth. Acta odont. scandinav., 18:101, 1960. Lysell, L.: Relationship between mesiodistal crown diameters in the deciduous and permanent lateral teeth. Acta odont. scandinav., 18:No. 2, 1960, Mathews, J. R.: Clinical management and supportive rationale in early orthodontic therapy. Angle Orthodontist, 31:35,1961___ : Interception of Class II malocclusion. Angle Orthodontist, 41 :81, 1971. Meredith, H. V.: Change in the profile of the osseous chin during childhood. Am. J. Phys. Anthropol., 15:247, 1957. Meredith, H. V., and Hopps, W. M.: Longitudinal study of dental arch width at deciduous second molars on children 4-8 years of age. J. D. Res., 35:879,1956. Qeconomopoulcs, c. T.: The value of glossopexy in Pierre'Robin syndrome. New England J. Med., 262:1267, 1960. Ravin, J. J.: Sequelae of acute mechanical traumata in the primary dentition, a clinical study. J. Dent. Children, 35:281, 1968. Sharma, P. S. and Brown, R. V,: The management of young dental patients. D. Practitioner, 17:419, 1967. Strock, M. S.: A new approach to the unerupted tooth by surgery and orthodontics. Am. J. Orthodontics & Oral Surg., 24:626, 1938.

Fig. 22-17, (Top) Lipbiting in the deciduous dentition, (Center) Overjet causes the lower lip to rest behind the maxillary incisors. When this becomes a pattern of closure, the permanent incisors will be in abnormal overjet and the faulty lower lip posture may initiate a Class II malocclusion. (Bottom) A plumper is attached to a lingual appliance to interfere with the faulty lower lip posture.

320 . Diagnosis and Treatment in the Deciduous Dentition Thompson, J. R: Early orthodontic treatment. Am. J. Orthodontics, 48:758, 1962. West, E. E.: Treatment objectives in the deciduous dentition. Am. J. Orthodontics, 55:617, 1969.

--_: Analyses of early Class II, Division 1, treatment. Am. J. Orthodontics, 43:769,1957. Wylie, W.: Assessment of anteriorposterior dysplasia. Angle Orthodontist, 17:97, 1947.

23 Diagnosis and Treatment in the Mixed Dentition SCOPE OF TREATMENT

7. Elimination of dentofacial, abnormal pressure habits 8. Approximation of abnormally spaced maxillary permanent central incisors (abnormal midline diastemas) until the permanent lateral incisors and canines are erupted. 9. Expansion of excessively narrow dental arches with teeth in lingual or crossbite occlusion. 10. Correction of crossbite, abnormal overbite, extreme overjet, and open bite after the permanent incisors are fully erupted and their roots are in the terminal stage of completion. When the deciduous molar roots are resorbed, treatment in the mixed dentition for widening the dental arch is ineffective. Light forces should be applied on deciduous teeth at all times when treating the mixed dentition.

Treatment in the mixed dentition can be either preventive, interceptive, or corrective. The primary aim is to correct dental arch irregularities and occlusal and jaw relation abnormalities and to eliminate functional interferences. Positional anomalies of individual teeth in children with both deciduous and permanent teeth cannot always be diagnosed on the basis of a single dental examination, since an apparent anomaly actually may be a stage in dentition development. Knowledge of the time sequence in the development of the child's dentition and ability to recognize the rate and direction of the general physical maturation of the child in relation to the development of the dental growth pattern are primary requirements, not only in preventive orthodontics but also in treating the mixed dentition. Many cases of apparent malocclusion in the mixed dentition actually are stages in dental development. Incisor irregularities, including midline diastemas, may be transitory stages in occlusal adjustment. Appliances used and the treatment itself should not interfere with the rapid changes in occlusal adjustment and continuing eruption of the permanent teeth. Extensive tooth movement of newly erupted permanent teeth should be avoided.

ANTEROPOSTERIOR OCCLUSAL CHANGES The following changes occur in the anteroposterior adjustment of the dental arches from the mixed to the permanent dentition: 1. Anteroposterior dental relation is established when eruption of the permanent dentition is complete. , 2. The maxillary and mandibular permanent molars shift forward when the premolars erupt. The mandibular permanent first molars shift forward more than the maxillary ones in the establishment of normal molar occlusion. 3. Intercanine space increases with the permanent dentition eruption. Crowding of teeth in the early mixed dentition may be treated in the following ways: 1. Expanding the dental arches to permit normal alignment. 2. Opening the palatine suture to widen the dental arch. 3. Serial extraction. A fixed and rigid orthodontic appliance that immobilizes the permanent molars can interfere with

INDICA nONS FOR TREATMENT Treatment of the following abnormalities may be undertaken in the mixed dentition period: -.1. Poor relationship of the dental arches, Class I, Class II, and Class III (Angle) malocclusion

2. Malposition and malrelation of permanent teeth after they have erupted fully 3. Elimination of supernumerary teeth 4. Treatment of ectopic teeth 5.Space opening to allow erupting permanent teeth to come into occlusion 6. Correction of labioversion of maxiIIary incisors

321

322 . Diagnosis and Treatment in the Mixed Dentition GENETIC INflUENCE ON DENTOFACIAL CHANGES IN MONOVULAR TWINS

Twins C.S. and 1.5. (Figs. 23-1, 2)

Fig. 23-1. Facial growth achievement in monozygotic twins. (Top) Full face of twins C. S. (left) and L. S. (right) at age 9 years. (Second row) Profile views at age 9 years. (Third row) Full face of C. S. (left) and L. S. (right) at age 13 years. (Bottom) Profile views

of C. S. (lefO and L. S. (right) at age 13 years. These twins were inseparable. Note the extreme facial resemblance.

Hie development of normal occlusion when the deciduous molars are being shed and the permanent molars are about to shift forward to occupy the "leeway" space as the premolars are erupting. (The leeway space is the difference in the mesiodistal diameters of the deciduous canine and the two deciduous molars, which usually occupy more space than their succeeding permanent teeth.)

Clinical Description. Patient C.S. at age 9 years, has a Class II, Division 1 (Angle) malocclusion. The maxillary right and left permanent central and lateral incisor teeth are erupted, spaced, and in protrusion. The mandibular right deciduous canine has been shed, and the space is almost completely closed by the shifted mandibular right lateral incisor. On the right side there is a cross bite of the deciduous first and second molars and of the permanent first molars. The mandibular right and left permanent central and lateral incisor teeth are erupted. The mandibular dental arch on the left side shows collapse lingually of the first and second deciduous molars. The mandibular incisors are spaced and overerupted; they occlude on the palatal gingivae. Patient L.S. at age 9 years, before treatment, shows exactly the same type of malocclusion as twin C.S., including the exfoliated mandibular right deciduous canine and closure of the space, cross bite on the right side, and lingual collapse on the left side of the mandibular first and second deciduous molars. Skeletal Classification. Both twins have a Class I facial skeletal pattern. The prominent chinpoint helps to bring the facial angle within low normal range. However, SNA and SNB are both well below the mean of normal range. This is usually found in young children when the face especially the mandible, is still growing. Treatment Summary. An extraoral appliance was used to correct the relation of the maxillary and mandibular dental arches. Edgewise arch brackets and round O.OISinch archwires, followed by 0.020inch archwires, were used for "leveling off" the occlusal planes and for eliminating interdental spacing. Activator appliances were used as retainers to confine the tongue and break the tongue thrusting habit. The activators were constructed so that they would not move the teeth or change intermaxillary or occlusal relations. The results obtained in treatment are stable. The tongue thrusting habit was stopped. One of the twins began to bite her fingernails; this produced slight crowding of her mandibular central incisor. At the age of 9 years these monovular twins showed six similar cephalometric dimensions. They showed a difference of lOin two dimensions, 20 in two dimensions and 3° in one dimension. After 2 years of orthodontic treatment, they showed only three similar dimensions; a difference of lOin four dimensions; a difference of 2° in two dimensions,

15. 16. 17. Fig. 23-2. (A, B) Dentitions of twins in Fig. 23-1 at 9 years of age. Note concordance in overbite and cross-bite. (C, D) Same twins at age 15, 2 years out of retention. The maxillary right central incisor in the twin on the left is inclined mesially, and the same is true of the maxillary left central incisor of the twin on the right. These are mirror . twins. The one on the left developed a nail-biting habit and disturbed the alignment of her mandibular left central incisor. This tends to mask somewhat the high degree of dental concordance. (E) Comparison of profile tracings at age 9. C. S. shows more forward growth than L. S. (F) At age 11, at completion of treatment, the twins show increased discordance of facial profiles, with C. S. continuing to show more forward growth than L. S., who shows more downward growth than C. S. This could be caused by the orthodontic intervention. (G) There is almost complete facial profile concordance at age 13. The genetic growth pattern reasserted itself, and environmental effects were not a factor in these twins.

Genetic Influence on Dentofacial Changes in Monovular Twins' 323

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and a difference of 3° in one dimension. At age 13 years, 1 Y2 years out of retention, the twins were again alike in six dimensions. There was a difference of 10

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324 . Diagnosis and Treatment in the Mixed Dentition through orthodontic therapy and the changes through genetic endowment and growth. These monovular twins show a high degree of concordance in their facial growth patterns. In the final analysis, genetics appears to have the most important role in the determination of the facial growth pattern.

ORTHODONTIC TREATMENT AND FA VORABLE GROWTH CHANGES 'Patient A.C. (Fig. 23-3)

lary and mandibular permanent first molars show a cuspto-cusp relation when viewed from the buccal aspect. This is frequently seen in the mixed dentition. However, since the mesiolingual cusps of the maxillary permanent first molars occlude in the central fossae of the mandibular permanent first molars, the occlusion is Angle Class I. There is incisor crowding in the maxillary dental arch. The right maxillary deciduous first molar interferes with the eruption of its succeeding premolar, which has emerged buccally through the mucosa. The maxillary right and left deciduous canines and deciduous second molars are still in position. The maxillary permanent first molars have erupted.

Clinical Description Before Treatment. The maxilFig. 23-3. (A, top left) Anterior view before treatment. (Right) Anterior view of same patient after treatment. There is a decided forward growth of the mandible. (Center left) Profile before treatment. (Right) Profile of same patient two years out of retention. (Bottom left) Anterior view of dentition before treatment. (Right) Anterior view of dentition two years out of retention. (B, opposite, top) Casts before treatment. (Center) Casts after retention. (Bottom) Occlusal views. (Left) Before treatment. (Right) After retention. Casts are oriented along Frankfort plane. (C) Superimposed tracings of patient A. C. show decided forward and downward growth of the face. (0, top) Tracings registered on the anterior nasal spine (ANS). Maxillary dentition grew downward and incisors were moved distally. (Bottom) Mandible registered on the inner plate of the symphysis. This shows general growth of the mandible, especially in a forward direction.

19. 18.

Orthodontic Treatment and Favorable Growth Changes· 325

PNS AC, -age 11yrs.

-- -age 15yrs.

"

c

326 . Diagnosis and Treatment in the Mixed Dentition Fig. 23-4. (A, top left) Profile view before treatment. (Right) Profile view at age 18 years, 5 years out of retention. (Center) Dentition before treatment age 10 years. B. Dentition of same patient at age 18 years, 5 years out of retention. (Bottom left) Face before treatment at age 10 years. (Right) Face at age 18 years, 5 years out of retention. Posterior teeth in good occlusion. Mandibular incisors show slight relapse. The mandible is retrognathic. (Opposite, B, top) Casts of same patient as in previous illustrations before treatment. (Center) At 5 years out of retention. (Bottom left) Before treatment and (right) 5 years out of retention. Casts are oriented along Frankfort plane. (C) Tracing of patient before the beginning of treatment, age 10 years; at 3 years out of retention; and at the age of 18 years, 5 years out of retention. The nasion kept growing forward as did the A-Point. The mandible grew slightly forward but mostly downward. The mandible continued to become more retrognathic in relation to the maxilla during growth.

The mandibular right and left permanent central and lateral incisors and permanent first molars are erupted. The right and left deciduous canines and first and second deciduous molars are in position. There is no mandibular crowding. The deciduous molars show progressive root resorption.

Skeletal Classification. The facial skeletal pattern is Class l.

Treatment Summary. This patient was treated without extraction. Extraoral force was used to the mandibular and maxillary dental arches to align the teeth. Edgewise arch bracket bands were used.

Orthodontic Treatment and Unfavorable Growth Changes· 327

20.

Fig. 23-4.

B

Round wire, 0.018 inches, followed by 0.020 inch arches with stops anterior to the molar tubes were used, and advantage was taken of the leeway space to move the mandibular incisors into less procumbency and to level the mandibular occlusal plane. Successful therapy depended to a great extent on proper timing of treatment, which took advantage of the leeway space. Favorable growth also aided in obtaining a good result. The occlusion is stable 2 years and 4 months out of retention.

Continued.

RB. Radiogram after treatment.

Ectopy and Impaction . 339

Fig. 24-7 A. (Left) The maxillary canines erupted on the palate. Orthodontic movement in such cases must use extremely light pressure to prevent root displacement. (Center) The canines are in position after treatment. B. (Right) This patient's maxillary canine is brought into position with a finger spring from an edgewise appliance. attempts to bring an ectopic or impacted tooth into position it should be ascertained that the tooth is not ankylosed.

Orthodontic Therapy When the patient's age and dental development indicate that a tooth is long past its physiologic eruption period and the position of the apex of the tooth indicates that the tooth will have to be moved through a considerable amount of bone, the prognosis for bringing it into arch alignment is poor. Otherwise, orthodontic therapy of impacted teeth is recommended. Buccal canine impactions, while less common than palatal ones, present special problems. The eruptive path of the canine is longer than that of any other tooth. The height of the canine tooth germ and the forward and downward path of eruption of the lateral incisor may cause the canine to be deflected palatally. Delayed resorption of the deciduous canine root may also cause the permanent canine tooth to become deflected. When the prognosis of an impacted canine tooth is questionable, or where other teeth may have to be sacrificed in trying to bring it into alignment, the canine may be allowed to remain im pacted or it may be removed surgically. Treatment of canine teeth in transversion with premolars can be accomplished when the premolars are not on a direct line with the canines by moving the premolars distally and the canines mesially. If 'the canine is in labial position, the labial plate

Fig. 24-8. This removable appliance is used for moving ectopically erupting canines into position (top). The lateral incisors were ageneticaIly absent. (Center) Appliance used, in position. (Bottom) canines were moved into position, a bridge supplied artificial lateral incisors.

340 . Diagnosis and Treatment in the Permanent Dentition

Fig. 24-10. Locating impacted canines. (Top) The radiogram on the left was taken with the central ray at the midline; that on the right was taken with the central ray at the lateral incisor. The canine moves in the opposite direction of the central ray. Therefore it is labial. (Bottom) The position of the canine changes in the opposite direction from that in which the film is taken. Again, the canine is labial.

Fig. 24-9. (Top) Spacing between maxillary incisor teeth. Removable appliances used with :Yg" rubber dam elastic. (Bottom) Same dentition after orthodontic therapy.

(Cente1')

and overlying mucosa may be lost during rapid tooth movement. When the canine is between the first and second premolars, or between the central 'and lateral incisors, but on a straight line, the transversion should be allowed to remain. Changes in the position of the canines in transversion are difficult to accomplish.

Surgical Exposure of Impacted Canines Surgery to expose impacted canines should in-

elude the removal of the bone slightly past the greatest diameter of the crown. The opening over the crown should be covered by a surgically packed crownform for about a week or until the mucosa around the tooth shows epithelization. Strock presented the following method of exposing unerupted maxillary incisors and canine teeth for the purpose of aiding their eruption: 1. Localize the crown of the unerupted tooth by radiographic means. 2. Excise the overlying mucosa. (Do not make a flap.) An electrosurgical scalpel, ordinary scalpel, mucoperiosteal elevator, chisel and mallet, hand chisels, or other instruments may be employed. 3. Remove the bone overlying the crown of the tooth to permit adequate direct access. 4. Establish a trough around the entire crown by removing the saclike portion of the tooth follicle, using scalers and periodontal files until the cementoenamel junction is reached. 5. Shape celluloid tooth crown form with heated bandstretching pliers until the neck of the celluloid

25.

Ectopy and Impaction . 341

Fig. 24-11. Locating impacted canines. (Top) The central ray was directed between

the central incisors for the radiogram on the left and for that on the right, at canine region. The canine tooth is palatal because it changed its position in the same direction as the central ray of the x-ray machine was moved. (Bottom) The canines are in palatal impaction for the same reason as above.

crownfonn is as wide as the greatest width of the tooth. Cut the neck of the crownform to fit the contour of the tooth crown. 6. Adapt the crownform to fit snugly over the crown of the tooth; it need not fit over the full length of the crown. 7. Sterilize the crownform and fill it with an obtundent ointment. Place it over the crown of the exposed tooth and leave it in place for a week to 10 days. It is advisable to provide space into which the tooth is to be moved before exposing the impacted tooth crown. If the impacted tooth is at some distance from the space into which it is to be moved, it is advisable to expose the toothcrown before the space is fully opened. Immediate Torsion of Teeth. Immediate torsion of teeth to correct irregularities actuaUy is autogenous replantation of teeth though the tooth never leaves the socket. Teeth so treated later show varying degrees of root resorption in most cases. Under local or general anesthesia the crown of the tooth on which a band has been placed is held by a forceps designed to preven tit from leaving the socket. A rotary movement is applied. When the tooth is loosened, it is turned but not pressed, apically. The tooth is then splinted to the ortho-

Fig. 24-12. A lateral cephalogram was used to locate an impacted canine tooth. (Arrow points to impaction.)

342 . Diagnosis and Treatment in the Permanent Dentition

Fig. 24-13. To locate an impaction a radiogram is taken from the position shown at left. (Center) The impacted canine is located palatally. (Right) The radiogram shows that a canine is erupting ectopically.

26.

Fig. 24-14. (Top left) Loop of electro surgical scalpel cutting into gum tissue. Dotted line indicates location of tooth. (Top right) Needle electrode coagulates the remnants of the dental sac so that it can be removed readily. (Center left) Tooth entirely exposed. (Center right) Neck of celluloid crownforrn being stretched with warmed pliers. (Bottom left) Crown being filled with ointment. Note how edges of crownform are festooned. (Bottom right) Crown applied to tooth. (Courtesy M. S. Strock)

dontic bands on the adjacent teeth and on the turned tooth. The turned tooth should be positioned so that it is not traumatized in function. , Successful surgical movement of teeth with incompletely formed roots is attributed to the rich vascularity of the apical region and the presence of undifferentiated mesenchymal tissue in the remnant of the dental papilla. This can produce the vascular supply needed for repair of stretched or torn tissues. Successful prognosis after this technique depends on the degree of root maturation, absence

of infection, and severity of the tooth rotation required. Replantation of Teeth. Replantation of teeth with incompletely calcified apices may be performed without pulp canal therapy, even though the nerve may be severed. The nerve may recover or root development may be atypical, and the pulp cavity may eventually be eliminated. Treatment of Mutilated Dentition. Patient S. B. (Fig. 24-15) has congenital facial asymmetry and microtia. The patient was born with stenosis of

Ectopy and Impaction . 343

27. 28.

E

S,B. -Before --- - After

I I

--,.L ,\

:

,~

.;},

IN

rl I'

7

33

40

'Score maxi Ilory or mandibular incisors. Na, - number of teeth affected, P .V. = point value.

6 6

TolOI score

2. Posterior Segment SCORE TEETH

RELATE MAN DI BULAR TO

AFFECTED ONLY

MAXILLARY TEETH DISTAL ~IGHi

M ESI AL

!-EFT

ee

1

Canine

1 st Premo lor

"

No. = number;

LEFT 5>

I 50

I

54

CROSSel TE RlGH T

"

LIE~T

51

5.

•a

I

51

55

so

s

ee

.0

ea

~IGHT

LE.F'T

es

"

••

70

.7

7'

••

7'

I

I

I

NO.

P.V.

SCORE

3 2Z.

Xl

3

Xl

'2.

Xl

t:

Xl

Z

OPENel TE

I

J

4•

lsI Molar

'RIGHT

4•

47

2nd Premolor

SCORE AFFECTED MAXILLARY TEETH ONLY

P.V. = point value;

Z.

'1

Total Score

'Add 8 points,when i ntrc-ond inter-o rch maxillary

~

JZ-

GRAND TOTAL'

inci sor score is 6 or more to denote esthetic hondicop.

REMARKS:

Prep

ere

d

by Dr. J. A. Salz.tnal"ln, opprovod by Ih~ Boord" of D"(letor$ of Americ=on the

As

Den'ol Heel th of the American Dental A.$$ocigllon.

Fig. 37-9E.

aeete

nen of OrthQdQnli!.u and

the

Ceun

cl

l

e

n

636 . Orthodontics in Public Health and Prepayment Programs

139. 140.

Fig. 37-10. See text. Continued, opposite.

A?

'B. Interarch Deviations: equal more than 6 points, 8 points are added. This makes an grand total assessment of 40 points for these casts (Fig. 37-11E). Use of the Index in Direct Mouth Examination The Supplementary Oral Assessment Record (Fig. 3721) is used when the assessment is made directly in the mouth of the patient. Dentofacial deviations, such as the following, that are not apparent on dental casts can be scored when the Index is used in direct mouth examinations. Eight points are scored for each dentofacial deviation. Facial and Oral Clefts. Facial and oral clefts (Fig. 3712) refers to malocclusion in association with clefts of the lip and palate. When the alveolar process is not involved in the cleft, orthodontic treatment priority is determined by the malocclusion score alone.

Lower Lip Palatal to Maxillary Incisors. The assessment of the rest position of the lower lip palatal to the maxillary incisors is made with the lips relaxed and the teeth in terminal occlusion (Fig. 3713). Jaw closure should be repeated until relaxation of the lips is obtained before the assessment is made. Occlusal Interference. Occlusal interference refers to the presence of malpositioned teeth that interfere with lateral, protrusive, or other excursive movements of the mandible (Fig. 37- 4A) Functional Jaw limitation. Functional jaw limitation refers to malpositioned teeth that interfere with or limit jaw movements usually required during mastication (Fig. 37-14B). Facial Asymmetry. Facial asymmetry refers to malocclusion that necessitates lateral or protrusive shifting of the mandible to obtain terminal occlusion so that lateral asymmetry of the face becomes evident (Fig. 37-15). Mandibular prognathism is shown

Defining Handicapping Malocclusion . 637

DEFINITION AND CRITERIA FOR ASSESSING HANDICAPPING MALOCCLUSION PERMAN ENT DENTI TION DEFINITION: Handicapping malocclusion and handicapping dentofacial deformity are conditions that constitute a hazard to the maintenance of oralhealth, and interfere with the well-being of the child by adversely affecting dentofacial esthetics, mandibular function, or speech.

HANDICAPPING MALOCCLUSION ASSESSMENT RECORD I

Ce s e No.

2

IliITI

3

4 Excmrne r No.

r=o

7

8

9

12

10 11

13 14 I, 16

Arcol=rrIIJ

DOI.~

~ A. INTRA·ARCH DEVIATION

SCORE TEETH

SPACING MISSING

CROWDED

POINT

ROTATED

NO.

VALUE

'Z

X2

SCORE

AFFECTEO ONLY OPEN

MAXILLA

MANDIBLE

Ant.

"

"

Post.

22

2>

27

28

I

'2

ae

2-

Ant. Post.

'0

J

CLOSED 2,

/

24

as

26

••

'0

ar

/

Xl

'4

ae

,.

Z

Xl

4-

Xl

Total

Score

Ant. ; anterior teeth (4 incisors); Post. ; posterior teeth (include canine, premolars and first molor).

I

z

1

No. ; n umber of teeth affected.

B. INTER-ARCH DEVIA nON 1. Anteri or Segmen t

SCORE MAXILLARY

OVERJET

OVER61 TE

EXCEPT OVER61 TE'

4-

37

t

so

C~OSS6ITE

i

TEETH AFFECTEDONLY.

I'·

*Sc:ore maxillary or mondibulor incisors.

OPEN61 TE

'0

NO.

P.V.

SCOR E

~

X2

/&

Total

SCore

/6

NO.

P.V.

I

Xl

No_ • number 01 teeth affected; P .V. = POInt value. 2. Posterior Segment SCORE TEETH

RELATE MANDI6ULAR TO

AFFECTEO ONLY

MAXilLARY TEETH DIS1 AL .R1-bHT

'-EFT

SCORE AFFECTED MAXILLARY TEETH ONLY

MESIAL LEFT

RIGHT

RIGHT

4,

45

'9

53

"

42

4'

50

"

ee

"

"

se

>2

ee

Canine 1 st Premolar 2nd Premo I Or 44

LEFT

'"

SCORE

OPEN6ITE RIGI-IT

t.EFT

"

ea

'0

53

71

J

Xl Xl

1st Molar No. = number;

CROSS61TE

ec

"

P. V. = point value;

6'

72

Xl Total Score

* Add 8 points, when intra-and i nter-o rch mo xi II ory

------- -------+

incisor score is 6 or more to denote esthetic handicap.

GRAN D TOT AL ~

REMARKS:

I 11

~z

Prepcred by Dr, J. A. Sol zmcnn, Qppro .••. ed by ,h", BOO;Jrd of Dt-eerer s of the Americon A5-S0l;iQtion of Orthedent! sis and the Council on Dee tel Health ~'the Amel ccn DcnlO;JI As s o cletlcn.

Fig. 37-lOE.

638 . Orthodontics in Public Health and Prepayment Programs

141.

A

Fig. 37-11. See text. Continued op-

posite.

in Figure 37-16, and a retrognathic mandible is shown in Figure 37-17. Speech defect should not be assessed by the orthodontist, general dentist, or hygienist without special training in speech pathology.

TREATME T DESIRABILITY The assessor completes the Treatment Desirability section without conveying the findings to the patient, the parent, or the teacher, each of whom is interviewed individually in turn. The treatment desirability section shows some rectangles to be omitted. The following instructions indicate by number the rectangles in which the various scores are to be entered (Fig. 37-21). Examiner or Assessor Treatment needed (TN). The assessor bases his decision on first impression. He checks Nos. 26, 27,

and 28 as indicated by esthetic deficiency, interference with function, or dental health. Patient The examiner checks squares 29, 30, and 31 as indicated. If the patient requests treatment or replies in the affirmative when asked if he desires treatment, squares 32, 33, and 34 are checked as indicated. If treatment is not wanted, square 35 is checked. Parent The examiner checks squares 36, 37, and 38 as indicated. The parent is asked if he has any questions about the patient's teeth. If not, the assessor asks if treatment is desired. If the reply is in the affirmative, the parent is asked if it is because it would correct the patient's dental irregularity, improve facial appearance, chewing, or tooth cleaning. Affirmative replies are checked as indicated in os.

Treatment Desirability' 639

DEFINITION AND CRITERIA FOR ASSESSING HANDICAPPING MALOCCLUSION PERMANENT DENTITION DEFINITION: Hondicopping molocclusion ond hondicopping dentofo eio l deformity ore conditions that constitute a hazord to the maintenonce of orol heolth, end interfere with the well-being 01 the child by c dver selv al." fecting dentofcc io l esthetics, mondibular lunction, or speech. HANDICAPPING MALOCCLUSION ASSESSMENT RECORD 1

Ca5i1t

2

3

4

No.1=rJIJ

7

S 9 10 11

12

DOI.1TTTTl

6 E)(omlner No. ~

13 14 IS 16

A'ooo=IITI

~ A. INTRA-ARCH DEVIATION

SCORE TEETH

SPACING MISSING

CROWOED

POINT

ROTATED

NO.

VALUE

SCORE

4-

X2

ff

Z

Xl

e:

AFFECTED ONLY OPEN >7

Ant.

MAXILLA

MANDIBLE

I

"

I' 24

Post.

n

23

Ant.

"

20

Post.

aa

20

.::i

"2.. eo

,.

CLOSEO

" ae

"

Xl Xl

as

10

T otol Score Ant. = onterior teeth (4 incisors); Post. = posterior teeth (include canine, premolors end lirst molor). No. = n umber of teeth affected, B. INTER·ARCH DEVIATION 1. Anterior Segment I

SCORE MAXILLARY TEETH AF FECTED ONLY. EXCEPT OVERBITE'

OVERJET

OVERSI TE

••

3

37

1-

"Score moxillary or mandibulor incisors. No. = number 01 teeth affected, P.V. = pornt vclue.

C~OSSBITE

,.

OPEN BITE 40

NO.

P,V,

SCORE

1

X2

/1-

NO.

P.V.

SCORE

Z 2-

Xl

7.-

Xl

~

2

Xl

2

2-

Xl

~ ~

Totol score

If

2. Posterior Segment SCORE TEETH

REL ATE MANDIBULAR TO

SCORE AFFECTED

AFFECTED ONLY

MAXILLARY TEETH

MAXILLARY TEETH ONLY

DIST AL LEFT

RIGHT

ee

41

Conine

"

1st Premolar

r

I

I

J .7

I

2nd Premo I ur 44

j

1st Molor No. = number;

I '6

P.Y.

MESI AL R((j.HT

L.EFT

4'

ee

50

OPEN srr

CROSSBI TE RtGHT

'LEFT

FUGH'T

L~F'T

"

01

6'

50

54

"

02

50

"

"

55

59

03

67

"

52

56

00

04

6.

12

I

s

Totol Score

;;;; point val we;

*Add 8 points,when intra-and inter-orch moxillary

If

incisor score is 6 or more to denote esthetic hondicap.

REMARKS:

GRAND TOTAL *

40

Prepered by Dr. J. A. Salzmann, oppro v e d by th~ BI;loQrd I;lof Dl rectcr s of ,h~ Am4!lrieor'll AS!Qdotion of Dr'''oo'ontists eed the Cl)Ur'IIeil on Dl:"Ilh:1I H4!loltJ-. of 'heAmerican Dl!'r'II te I A$~Qc;iQtion.

Fig. 37-11E.

640 . Orthodontics in Public Health and Prepayment Programs

Fig. 37-12. See text.

Fig. 37-14. A, B. See text.

Fig. 37-13. See text.

39, 40, and 41. If treatment is not wanted, square 42 is checked. Teacher or urse The examiner (assessor) checks squares 43, 44, and 45 as indicated. If treatment is requested voluntarily or in reply to a question, the assessor asks if the reason is to correct dental irregularity, facial appearance, or as an aid in chewing or tooth cleaning. Affirmative replies are checked as indicated in as. 46, 47, and 48. If treatment is not wanted, square 49 is checked. The section on Treatment Desirability provides a

Fig. 37-15. See text.

Treatment Desirability· 641

Fig. 37-16. See text.

Fig. 37-17. See text.

2

A

B

A.

69 cases accepted by index assessment

A,

33 cases rejected by index assessment

B,

61 cases accepted by clinical judgment

B.

33 cases rejected by clinical judgment

8 cases rejected (see note 11

4

8 cases accepted (see note 2)

same cases used for both

NOTE L OF 8 CASES WITH INDEX ASSESSMENT OF 17 POINTS OR MORE REJ ECTED BY

cu NICAL JUDGMENT, 2 REQUIRED PROSTHESES, 2 HAD REGULAR ARCH

ALIGNMENT WITH MESIO·DISTAL DEVIATIONS, CLINICALLY CONSIDERED NOT HANDICAPPING, AND 4 WERE CONSIDERED OUTSIDE THE SCOPE OF THE STATE PROGRAM. THE INDEX FORM PROVIDES FOR THESE NOTATIONS UNDER DIRECT MOUTH ASSESSMENT WESTCHESTER COUNTY, N,Y. SCREENING CENTER NEW YORK STATE BUREAU OF DENTAL HEALTH ORTHODONTIC PROGRAM

"REMARKS".

NOTE 2. OF 8 CASES WITH INDEX ASSESSMENT OF LESS THAN 17 POINTS, ACCEPTED BY CLINICAL JUDGMENT, THE DEVIATIONS WERE CONFINED TO THE INCISOR REGION AND WERE CONSIDERED HANDICAPPING. THE INDEX FORM PROVIDES FOR THESE

Fig. 37-18. (Courtesy Dr. Norman D. Allen)

NOTATIONS UNDER "REMARKS".

642 . Orthodontics in Public Health and Prepayment Programs

Fig. 37-19. (A) Enlarging mirror used in examining for rotated, crowded, spaced and missing teeth. (B) Metal mirror and cheek retractor used in examining the dental arches.

Fig. 37-20. (A) Head position and cheek retraction for intraoral examination except for overbite. (B) Retraction of cheek for anteroposterior occlusion examination. (C) Intraoral examination for overjet and overbite. (D) Intraoral examination for overbite. (E) Intraoral examination for anteroposterior deviations (Courtesy M. M. Feldman).

Bibliography' 643 SUPPLEMENTARY ORAL ASSESS.ffi~T RECORD

Cue NO)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 IJl9.rrnEx~miner NornD"telTTTllere~ ~ ~ C. DENTOFJlCIJlL DEVIATIONS

III

15 16 17 18 19

IIIII

Locution

The following devietionc ere scored eB hendicopping when OBsociated with melocclusion: Score 8 points for each devietion. 1. Faciel end orel c1@fts 142. 143. 2.

Low@r lip pDlatel to mDxi11ery incisor teeth

3. Occlusel interference 4 . 5. F~cial esymmetry 6. Speech impeirment Totel Scor D. TREATMENT DESIRABILITY ~. The exeminer should not suggest the need for treatment. Check repHe.

exJ>,MINER T.N. T.R. N.W.

Fechl 26 esthet ics Function 27 Dental ltygien"

PARE-N'r

N.W . 35

T.N. T.R. N.W. 36'39 42

TEI\CHER T.N. T.R.C.W. 43

46 49

28

T.N.· - Treetment needed T.R. - Treatment requested ~.W. - Treatmont not wanted or needed Rernerksl Mention deviation not included in this ~sscssment record form.

Fig. 37-21. Supplementary Oral Assessment Record.

clue to the degree of patient and family cooperation that can be expected. This may help avoid wasting manpower and available funds. Allen described the use of the Index in direct mouth examinations of prospective orthodontic patients in the following manner:

tion is a valid and practical method of assessment. Direct mouth examinations can be used also in epidemiologic surveys of malocclusion or the assessment of large numbers of children for prepayment or public health orthodontic care programs (Fig. 3718).

The patient is seated in a dental chair with the head tipped back and the mouth sufficiently open to permit a clear view of the entire dentition (Fig. 37-18A, B, C). The assessor must be able to view the dental arches from the front of the mouth for assessing overbite and overjet, and the buccal series of teeth at a right angle to the occlusal plane, in order to assess the mesiodistal relation of the mandibular to the maxillary dental arch. A magnifying hand mirror and metal mirror cheek retractor are useful for this purpose (Fig. 37-19A and B). The patient is asked to "bite on the back teeth." The occlusion is checked to ascertain that the mandible is not thrust forward or to one side. Overbite is assessed with the patient's head level and overjet with the head tipped back. Allen examined 110 children to determine the accuracy of direct mouth examination using the Index. The results indicate that the use of the Index in direct mouth examina-

BIBLIOGRAPHY Allen, N. D.: Handicapping malocclusion assessment record in direct mouth examination. Am. J. Orthodont., 58:67, 1970. Ast, D. B., Carlos, J. P., and Cons, N. c.: The prevalence and characteristics of malocclusion among senior high school students in upstate New York. Am. J. Orthodont.. 51:437,1965. Baumgartner, L.: Orthodontics as a public health service. Am. J. Orthodont., 47:809, 1961. Byrne, J. J.: Assessment of malocclusion: Implications for dental prepayment programs. Am. J. Orthodont., 54:766, 1968. Council on Dental Health, American Dental Association. Prepaid dental care programs, Am. J. Orthodont., 48:778, 1962.

644 . Orthodontics in Public Health and Prepayment Programs Hixon, E. H., et al.: On Force and Tooth Movement. Am. J. Orthodont., 57:476, 1970. Salzmann, J. A.: Principles and Practice of Public Health Dentistry, Boston, Stratford, 1937. --_: Orthodontics as a public health activity. Am. J. Orthodont., 35:179, 1949. Salzmann, J- A, et al.: Fact finding report on health services-Orthodontics. Am. J. Orthodont., 37:50, 1951Salzmann, J. A, and Moore, G. E.: The White House conference and orthodontics. Am. J. Orthodont., 37:426, 1951Salzmann, J. A: The Michigan workshop in orthodontics.

Am. J. Orthodont., 45:55, 1959.

--_: Orthodontics in prepaid dental programs, Am. J. Orthodont., 49:776, 1963. Salzmann, J. A.: Malocclusion severity assessment. Am. J. Orthodont., 53:109, 1967. Salzmann, J. A.: Handicapping malocclusion assessment to establish treatment priority. Am. J. Orthodont., 54:749, 1968. Strusser, H., and Simon, L. A: Orthodontics in public health practice. Am. J. Orthodont., 40:654-670, 1954. Squires, F. A., Salzmann, J. A, Howes, A E., and Bedell, W. R: The advisory committee on orthodontics in the public health program. Am. J. Orthodont., 46:220223, 1960.

Index Numerals in italics indicate a figure, "t" following a page number indicate a table.

Abnormalities. See Malformation(s) Activatorts), 556-591 action of, theories of, 570-578, 572-578 advantages of, 590-591, 619, 619 casts for, 578-579 application of separating medium to, 584 placement of acrylic on, 584, 587 Class II, correction of malocclusion with, 558, 563-565, 556. 557, 558, 560, 562, 568, 569, 570 eruption of teeth with, 581, 572, 572573. 582, 583 extension of acrylic of, 583, 585 working bite for, 572 Class III, correction of malocclusion with, 588-590, 589 eruption of teeth with, 581-582, 584 exten sian of acrylic of, 583, 585 labial archwire for, design of, 583, 580, 585 construction of, 578-586 bite registration for, 578-579, 579 and manipulation of, for Class II correction, 586-588,570,572,572-573, 585, 587, 588 contraindicatioris to, 591 disadvantages of, 590-591 dislodging springs for, formation of, 580-581, 582 facial changes and, 558, 557, 558 facial conditions best managed by, 562565,568,569,570 facial growth and, 561, 563-565, 566 frontal view of, 572-573 functional occlusal plane changes in Class II treatment with, 568-570, 570, 571 indications for, 591 intermittent forces of, tissue changes and, 605606, 606 intrusion of teeth and, 560 labial arch wire of, design of, 579, 556, 572-573, 580 limitations of, 556-567 lingual relief of, 579-580, 573, 581 mandibular growth change with, 559560,561 in mandibular relocation, 385, 386 masticatory muscle reaction to, 606-607

modified, in edge-to-edge bite, 383 occlusal changes and, 558, 559 skeletal dysplasia correction with, 558, 560 tooth eruption control with, 558-559, 565, 560, 570 trimmed, inferior view of, 572-573 lateral view of, 571 right buccal segment of, 571 superior view of, 572-573 trimming of, prefabrication of, 581-583, 582 procedure in, 584-586, 572, 572-573, 585 untrimmed, lateral view of, 572-573 uses of, 556-567 vertical manipulation of dentition with, 560-561, 560, 561, 562 Adams clasp, 298 Adolescent, as patient, 3 dentofacial growth changes of, influence of treatment on, 351-353, 352-354 Adult(s), skeleton and musculature of, and of newborn, compared, 6 skull of, 7 treatment of, 373-386 case report of, 377-378, 379 Age, as factor in treatment, 146, 147 changes in facial growth and dental development, 20-21. dental, assessment of, 143 in deciduous dentition, 310 skeletal, assessment of, 79-80, 142-143 tooth eruption and, 29 Agenesis of teeth, 126, 127, 128, 129, 131 Alastics. 283 Alveolar process, ankylosed teeth and, 131 growth of, 249 and maxilla, supraclus ion of, and buccoelusion of maxilla, 55 American Association of Orthodontists, interceptive orthodontics defined by, 211 -Salzrnann treatment priority index, 629-643 assessment of dental casts in, 632-636, 633-639 assessment of patients for, 629-630, 630 direct mouth examination and, 636-

645

638, 643, 640-642 establishment of treatment priorities in, 630631, 630 treatment desirability section of, 638-643 use of, as bas for fees, 631 instructions for, 631-638, 643, 631642 American Dental Association Council on Dental Health, on acceptance of patients for pu blic health orthodontic programs, 629 American Public Health Association, on orthodontics, 628 Analysis, cephalometric. See Cephalometric(s), analysis Anchorage, 275-277 compound intermaxillary, 275 definition of, 420 extra oral, 276 labiolingual technique and, 498, 499 loss of, 276 occipital, 276 problem, hypothetical, 419 reciprocal tooth movement and, 419-420, 419,420,421 reinforcing of, 276-277 resistance offered by, 276 simple, 275 simple reciprocal intermaxillary, 275 simple reciprocal intrarnaxillary. 275 simple stationary, 275 sta bili ty of, 276 types of, 275- 276 Angle, classification of malocclusions, 54-65,55 edgewise appliance, 408-409, 408-409 Ankylosis, in deciduous and permanent dentition, 130-132, 130 of primary molars, 240-241, 243 Anodontia, causes of, 126 Appliance(s), activator. See Activator(s) active, 277 Andresen. See Activator(s) antithumbsucking, 229, 228, 229 arch-widening, 403 in B gg technique, 440-442, 440, 457-459 Birnler, 556, 556 biteplate, 162-163 in Bruxism, 381, 384

646 . Index Appliance(s) - (Cont.) cervical, 277. 302. 304 chincap, 164, 310-312,303,311 for developing Class III malocclusion, 312,311 in mandibular prognathism, 313 construction of, 288-306 model conservation and, 481-482 Crozat, See Crozat appliance edgewise. See Edgewise appliance extraoral, asymmetrical, 301 cervical, 277. 302, 304 construction of, 304, 302 distal driving and, 303-304 facebow angulation of. direction of tooth movement and, 301-303 force of, 300-301 high-pull, 277 for nighttime use, 299 fixed, components of. 410 interrupted forces and, 605, 602 fixedremovable. in crossbite, 226-227, 227 force exerted by, factors determining, 279 Frankel, 556, 557 in labiolingual technique, 500, 499 hayrake, 161. 229, 159, 229 high-pull extraoral. 277 inclined plane, acrylic, 223-224,223,224, 225 labial, 220 labiolingual. See Labiolingual technique lingual, 288-291 activation of. 291 applications of, 290 arch stabilizing, 149-150, 151 auxiliary springs on, 291 holding, 237-238, 238 locks and loops on, 289 Porter, 220, 220 tooth rotation and, 288-289 wire in, gauges of, 292 lower traction, 299 Mershon, 289-291. 220. 289. 291 midpalatal suture-opening. See Midpalatal suture opening oral screen, construction of, 148, 149 orthorehabilitative. 215 palatal bar, 161. 159 passive, 277 in clefts, 405 plumper, 158, 158 removable, 277, 293-297 for bite opening, 156 in crossbite, 224-226. 226 intermittent forces of. tissue changes and, 605606, 606 mandibular, 155 for movement of ectopically erupting canines, 339 requirements of, 288 safety measures and, 288 space maintaining, 148-149,215,150,216 space regaining, 215, 216 speech, in cleft palate, 402

split-plate, 161-162,395,397,400 stabilizing plate. See Stabilizing plate stainless steel. 292293, 292 twinwire. See Twinwire appliance upper traction, 299 use of, 288-306 Archtes), anteroposterior adjustment of, from mixed to permanent dentition, 321 basal. areas covered by, 154 changes in, cephalometric analysis and, 194 discrepancies in, 154 of maxilla and mandible, 95 relationshi p of, 96 prognathism, 364 Salzmann's, 89 branchial, abnormalities of, 107-111 collapse of, prevention of, 149-150, 151 constricted, molar region of, 19 expansion of, twinwire appliance in. 460-462, 460 length, available, 211-213 deficiency of, methods of correction of, 409 increase in, 17 measurement of. 212-213, 212 required and available, Tweed method of establishing, 272 lingual, expansion of, round and halfround tubes and, 290 mandibular, collapse of. and microglossia, 333-334, 332-334 treatment of, 251 radiography of, 168, 170 maxillary, alignment of, following cleft lip closure, with segment guidance, 405 without segment guidance, 404 collapse of, in clefts. 392, 396. 402-404 following premolar extraction. 252 narrow, midpalatal suture opening in, 542-544 overexpansion of, 621 radiography of, 168-169, 169 normal, and shifting of teeth following extraction, 116 permanent, size of, estimation of, 262 width of. archwire and, 417 Archwire(s), arch width and, 417 in Begg technique, 440, 458. 459 configuration of. alignment of teeth and, 417-419, 417. 418 formation of, 414-419 functions of, 410 ideal, 419, 418 labial, of activator, Class III, design of, 583, 580. 585 design of, 579, 556, 572-573, 580 mandibular, for labiolingual technique, 498499 maxillary, for labiolingual technique, 495-496, 495, 496, 497 lingual, for labiolingual technique, attachments to, 487-493, 487-494 precious metal, for labiolingual tech-

nique, 482-484 stainless steel, for labiolingual technique, 484-486, 484, 485, 486 lingual holding, 237-238. 238 loops. 281-283 materials for, 410 resiliency of, 414-417, 416 second-order bends in, 281 steel. force of. 278 Articulation, mandibular, structure of. 99 temporomandibular. See Temporomandibular articulation Assessment, bone age, 79-80

Band(s), contour of, 411 fitting of. 412-414, 414. 415 function of, 410 in labiolingual technique, 480-482, 495, 482. 483, 495 materials for, 410-411 methods of separating teeth for, 292, 289 placement of, 414 preformed, 410 in twinwire appliance, 461-462, 461 Begg technique. 438-459 appliances in, 440-442, 440, 457-459 fundamental concepts of, 438 retention following, 459 treatment with, case histories illustrating, 442-459, 441-457 diagnosis in, 442 effectiveness of, 438-440 stages of. 438, 439 Benninghoff's lines of stress, profile of skull showing, 95 Bicuspids, band fitting and bracket placement on, 413, 413 Bimler appliance, 556, 556 Biomechanic terms, 274-275 Biomechanics in orthodontic therapy, 274-287 Bite, dual. 618 "jumping," 304-305 registration. for construction of activator, 578579, 579 neuromuscular concepts of. 570-578, 572-578 Bite opening, extraoral appliance and, 303 removable appliance for, 296 Biteplanes, changes effected by, 162, 163, 295296 Biteplate(s), construction of, 300-301 elongation of posterior teeth and, 294-295, 303 for tooth movement, 162-163, 294 Bi te-raising. 381-386 Biting, fingernail, 121-122. 123 lip, 121 Bjork's facial analysis, 204-206,204,205 Body proportions, of newborn and adult, compared,6 Body type(s), athletic, 75 leptosomatic, 75 pyknic, 75 skeletal classification according to, 75

Index' 647 Boley gauge in measurement of arch length, 212, 212 Bone(s), age assessment, 79-80, 142-143 alveolar, resorption of, tooth movement and, 592-593, 594 teeth as functional matrix for, 25 bundle, arrangement of, and tooth movement. 604, 603, 604 centers, in hand, range of time of appearance of, 83t changes, in adult, 373-374 cranial. See Skull deformation, theories of, 598-600, 599 deposition, internal. in posthyalinization period, 600, 601 . physiologic tooth movement and, 592, 593 displacement of, in mid palatal suture opening, 552, 551, 553 facial, development of, 6 of fetus, 9 formation, in abnormal labial frenums, 152 types of, 9-10 grafting, in cleft palate, 401-403, 405 growth of, types of, 26 lability of, 9, 9 long, structural details of, 8 orthodontic therapy and, 9-10 regeneration of, following mid palatal suture opening, 549-550, 549 resorption, orthodontic tooth movement and, 593-594, 594 physiologic tooth movement and, 592 593 undermining, 596, 595, 596 structure, factors influencing, 9 and teeth, differences between, 30 type, hyalinization of periodontal tissue and, 596, 593 Bracketts), attachment of, to enamel. See Direct Bonding System in Begg technique, 440-441, 440, 457 edgewise, 409, 409, 410 functions of, 410 modifications of, 411-412, 411 placement of, 412-414, 41~, 416 and tube set-ups, 412, 412 Brain, case, growth of, form-function relationship in, 25 expansion of, 16 Branchial arch abnormalities, 107-111 Bruxism, 122-123, 381 appliance in, 381, 384 Buccoclusion, of maxilla, and maxillary and alveolar supraclusion, 55 Bumper, lip, 148, 151

Calcification, of teeth roots, deciduous, 4 permanent, 42 Calvaria, growth of, form-function relationship in, 25 Canine(s), deciduous, grinding of incisal tips of, 316

1

occlusal relation of, 45, 46, 45 premature loss of, 315 development of, from birth to age fourteen, 30-41 ectopic eruption of, 126, 128, 134, 339 extraction of, 250 high, 135, 137 impacted, Direct Bonding System in, 437, 436 locating of, 337, 340, 341, 342 orthodontic therapy in, 339-340 surgical exposure of, 340-341, 342 movement of, force and, 279 permanent, occlusal relation of, 46, 48, 47 shaped to resemble lateral incisor, 337 Caries, dental occlusion and, 19 and malocclusion, 3, 122 and orthodontic treatment, 3 Cartilage, Meckel's, development of, 11 Centric occlusion, and centric relation, 618 of mandible, 97, 98 Centric relation, and centric occlusion, 618 of mandible, 97, 98 Cephalogram(s), accuracy of, 176 45 degree, 179 head position, natural, 178 information obtainable from, 183 lateral, 177-178, 178 comparison of, by mesh diagram, 210 oblique, 179 tracing of, 188 without cephalometer, 179, 180 magnification and distortion in, 176 mandibular rest position, 178 posteroanterior, 178 of ramus of mandible, 179 tracing of, 179-181, 188 in check of efficacy of treatment, 248 use of, 176 Cephalometer, 176, 177 Cephalometric(s), analysis, 197-210 denture, 194-195, 192 Downs', 197-202 facial, Bjork's, 204-206, 204, 205 mandible, 193 maxilla, 193 Moorrees mesh diagram in. See Mesh diagram, Moorrees' profile, 193,192 Ricketts', 202-203, 201 Sassouru's, 206-207, 205 skeletal, 193-194, 191 angle(s), 190 Gonion, variations in, 192 in evaluation of growth, 195-196, 193, 194, 195 Frankfort-mandibular plane angle in, 190, 194 Frankfort plane, 187-188, 194 landmarks, 183-186 commonly used, 189 lateral, 184, 186 and measure points for clinical use in, 189, 190 posteroanterior, 184. 185 variations in, 192, 189

lines, 186-189, 191 maxillofacial triangle in, Margolis', 203- 204, 203 measurements, Downs', 198-200, 198-200 planes, 186-189, 191 radiographic, 176-182 clinical value of, 183 in diagnosis and treatment, 183-196 in examination, 143 limitations of, 190-191 reference lines in, 191-192 techniques in, 176-179 tracings of, superimposition of, 195, 193, 194, 195 uses of, 176 standards, Downs', 198t Ricketts', 202-203 University of Washington, 202t technique, standardization of, 183 Yvaxis, 190, 194 Charts, diagnostic examination, 143-144 Child(ren), as patient, 2-3 comparison of hands of, from age 6 to age 15, 89-93 development of dentition of, from birth to age 14,30-41 temporomandibular articulation of, and of adult, compared, 99 Chincap. 164,310-312,303,311 for developing Class III malocclusion, 312, 311 in mandibular prognathism, 313 Chlorobutanol, 4 Chromosomal aberrations, and clefts, 387, 390, 391 Clasp, Adams, 298 Schwarz arrowhead, 298 Clasp knife reflex, mechanism of, 577 Classification, in deciduous dentition, 53 dental, variation of, 75-79 of malocclusion, Angle, 54-65, 55 Class I, 54 Class 54-55 Division 1,55 Subdivision, 55 Division 2, 58-65 Subdivision, 65 Class III, 65 skeletal. 75-94 variation of, 75-79 Cleft Ii p, chromosomal aberrations and, 387, 390, 391 dental abnormalities in, 387-389 etiologic factors in, 10, 387 formation of, stages of, 387 parent counselling in, 406 types of, 387, 388 Cleft palate, 387-407 bone grafting in, 401-403, 405 chromosomal aberrations and, 387, 390, 391 collapsed, treatment of, McNeil's technique for, 399-403, 397-398 crossbi te in, 399-400,403 dental abnormalities in, 387-389 etiologic factors in, 10, 387

n.

648 . Index Cleft palate- (Cont.) extractions in, 392 formation of, stages of, 387 not involving alveolar process, 400 oligodontia in, 393, 403 orthodontic intervention in, 389-396 contraindications to, 393-394, 393 results of, 394 timing of. 391-392 orthopedics, 396-403 parent counselling in, 406 postoperative anomalies in, 396, 392 prosthesis in, 394-395, 401 radiography in, 391, 393 rehabilitation in, 394 speech, 403-406 supernumerary teeth in, 395 transmission of, 387, 389 types of, 387, 388 Clicking of temporomandibular articulation, 100 Coil, Pletcher, 305 spring force, 280, 282 -springs. in twin wire appliance, 462, 462 Condyle(s), changes in, 196 mandibular, growth of, 10, 9 movements of, 99 malocclusion and, 100 Copalite,4 Coronoid process, and temporalis muscle, formfunction relationship of, 25 Cranium. See Skull Crossbite(s),215-227 anterior, 220-221 buccal, midpalatal suture opening and, 551 in cleft palate, treatment of, 399-400, 403 in deciduous dentition, 217, 316-318, 217.308.310 labiolingual technique in, 480, 481 in mixed dentition, 217, 217, 218 posterior, degrees of. 220 functional, detection of, 219-220, 219 unilateral, 219 right maxillary, with exception of central incisor, labiolingual technique in, 506512,509-511 simple incisor, characteristics of, 221. 221 correction of, acrylic inclined plane appliance in, 223-224, 223. 224, 225 fixed-removable appliances in, 226227,227 gaining cooperation from patient in, 221-222 removable appliances in, 224-226, 226 tongue blade technique in, 222-223, 218. 222 treatrnen t of, 220 early, 215-219, 217, 218 Crozat appliance, 513-514 acti vation of, 524-527 adjustment of, 522-524, 523-524, 525-526 clasps of, construction of, 513-514, 516 in Class II, Division 1 malocclusion, case

histories of, 527-531, 537, 528-530, 538541 Division 2, Subdivision malocclusion, case history of, 531-534, 532-534 construction of, 514-521 materials and tools for, 514, 527t crescent of, mandibular, formation of, 515-516, 516 maxillary, formation of, 519 cribwire of, mandibular, bending of, 515, 515, 516 maxillary, bending of, 518-519. 518 Crozat on, 513 finished, 521, 522 insertion of, 521-522 lingual bodywire of, mandibular, construction of, 516-517, 517 maxillary, construction of, 519-520, 519, 520 occlusal rest wires of, 517-518 in rotation of molars for space gain, case history of, 534-537, 535-537 soldering of, 520-521. 520, 521 Curve of Spee, 19 Cuspids, band fitting and bracket placement on, 413, 413

Deformation, definition of, 275 Dental care, general, 3-4 Dentinogenesis imperfecta, in ectodermal dysplasia, 115 Dentist, family, orthodontics and, 1 Dentition. See Tooth(Teeth) Development, of clefts, 10 definition of, 6 and growth, record charts, 563-565 of mouth, 10, 10 occlusal, guidance of, 145-166 scope of, 145 of teeth, deciduous, 30-35. 31-32 permanent, 35-42, 33-41 of tongue, 11 Diagnosis, in deciduous dentition, 307-320 of ectopy, 337 in mixed dentition, 321-334 in permanent dentition', 335-372 of prognathism, 353-361 of supernumerary teeth, 120, 230-231. 231, 232, 233 of temporomandibular dysfunction, 100 Tweed triangle in, 248, 270-271, 252 Diastemajs), abnormal, causes of, 116-117, 152. 153 in deciduous dentition, 316 midline, in adults, treatment of, 374, 384 Differential force, 279 Direct Bonding System, 434-437 advantages of, 434 bonding technique in, 434-435, 434-435 bracket removal in, 435 clinical use of, 435-437, 436 disadvantage of, 434 Disease(s), periodontal, malocclusion and, 111,150-152

renal, dentition and skeletal features in. 111-112 severe, dentition and skeletal features in, 110-111 Distoclusion. See Malocclusion. Class II Downs' cephalometric analysis, 197-202 Ductility, definition of, 275 Dwarf, achondroplastic, dentition and skeletal features of, 108-109 Dyslalias, malocclusions and, 101 Dysostosis, orodigitofacial. dentition in, 107 Dysplasia, ectodermal, hereditary, dentition in, 115 skeletal, activator in, 558, 560

Ectodermal dysplasia, hereditary, dentition in. 115 Ectopy, diagnosis of, 337 Edgewise appliance, 408-433 band fitting in, 412-414, 414, 415 bodily movement and, 605 bracket, 409, 409, 410 modifications of, 411-412, 411 placement of, 412-414, 413 and tube set-ups, 412, 412 in complex malocclusions, case reports of, 421-433, 422-432, 423t, 427t components of, 410-412 development of, 408-410 E arch, 408, 408 modifications of, 409-410 pin and tube, 408, 409 ribbon arch, 408-409, 409 uses of, 408 Elasticity, definition of, 275 Elastics, force produced by, factors influencing, 283 intermaxillary, force of, 284-285 hooks for, 300 in space closure, 284 with mouth open and closed, space diagrams of, 284 vector diagrams of, 283 lingual and buccal, in space closure, 284 modification of pull of. 283 Oliver guideplane and, 490 uses of, 283 Enamel, direct bracket attachment to. See Direct Bonding System etching, 4 Endocrine imbalance, dentofacial manifestations of, 111 Environmental factors, effects of, on dental genotype, 43, 44 Equilibration, occlusal, 623-626, 625 Eruption, control of. activator in, 558-559, 565, 560, 570 delayed, causes of. 126, 132, 136, 137, 139 surgical exposure of teeth in, 238-239, 240, 241

ectopic, 126-128, 134,135, 137 facial growth in depth and, 15 mean ages of, 29 order of, 30

Index' 649 effect of. on deciduous dentition, 315-316, 314, 315, 317 Etching, enamel, 4 Etiology, of malocclusion, 103-125, 103 acquired, 104·106 classification of, 103-106 dentofacial pressure habits in, 120-123, 118-119, 120, 121 endocrine imbalance in, 111 environmental, 104-106 functional, 104 genetic, 106-111 mandibular incisor crowding in, 123 midline deviations in, 115-119 mouth breathing in, 112 periodontal disease in, 111 postnatal factors in, 103-104 prenatal factors in, 103 supernumerary teeth in, 119-120 temporomandibular disturbances in, 111 tongue posture and function in, 113115 Examination(s), charts, diagnostic, 143-144 history in, 142 oral, 143 parameters in, 142 photographic, 143 posture, 142 roentgenographic, 143 scope of. 142-143 serial, 142 skeletal signs in, 142 of tongue thrusting, 159-160 Exfoliation, premature, 132-134 Expansion screws, 161-162 Extraction(s), in abnormal overjet or overbite, 157 of canines, 250 child and, 3 choice of teeth for, 250-257 in Class II, Division 1 malocclusion, 247 Division 2 malocclusion, 247-248 in cleft palate, 392 criteria for, 246-248 of deciduous teeth, indications for, 312-314, 314, 315 eight-tooth, Begg technique following, 453459, 453-457 facial profile and, 249-250, 250 of incisors, mandibular, 256-257 in procumbency of. 247-248 relapse following, 620 of molars, first permanent, 251-253 occlusal changes following, 117-119 second permanent, 253-256, 256 third, impacted, 256 orthodontic therapy without, case histories of. 264-270, 266-267, 268-269 of overretained primary teeth, 239-244, 242, 243, 244 of premolars, first, 25