A R T IC L E S
In d ic a tio n s f o r o r th o d o n tic -p r o s th o d o n tic c o lla b o r a tio n in d e n ta l tre a tm e n t C a ria A . Evans, DDS, D M S c D a n N a th a n s o n , D M D
A com bined orthodontic-prosthodontic approach g re a tly benefits p atients needing comprehensive d ental care. Im provem ents in fu nction, o ra l health, and esthetic appearance can be re a liz e d by a p p ro p ria te ly p la n n in g the sequence and the tim in g o f treatm ent procedures.
A JL I s the p ub lic becomes more con cerned about long-term dental health and preservation o f natural d en ti tion, patients more re a d ily accept complex plans of treatment that are directed at establishing optim al oc clusion and integ rity of the dental arch. Coordinated programs o f or thodontic and prosthodontic treat ment have recently become more fre quent, especially as use of orthodon tic appliances by adults has become socially accepted .1 A survey of or th o d o n tis ts p u b lis h e d in 1977 sh o w e d th a t a d u lt p a tie n ts ac counted for more than 10 % of the pa tients in approxim ately h a lf of the or th o d o n tic practices .2 O rth od on tic appliances are also used in the treat ment o f adults by periodontists and dentists perform ing restorative pro cedures. Nevertheless, more patients c o u ld b e n e fit fro m c o o rd in a te d prosthodontic-orthodontic treatment after benefits of this approach be come better known. In coordinating orthodontic and prosthodontic treatment plans, restor a tio n o f n o rm a l fu n c t io n and achievement o f a nonpathogenic dis tribu tion of occlusal forces are key objectives. A lthough occlusal aberra tions alone do not cause periodontal
disease, the co m bination o f local b a c te ria l ir r ita n ts and o c c lu s a l trauma may lead to progressive de struction o f bone .3,4 M alpositioned teeth are more d iffic u lt to clean and are associated w ith an altered d is tri bution o f stress in the alveolar bone and periodontal ligam ent, such as around tipped m olars .5 Several categories o f collaboration of o rth o d o n tic and pro stho d on tic treatment w ill be described to em phasize the importance of a carefully planned approach to the patie nt’s needs o f com prehensive care; to demonstrate possible periodontal, biomechanical, and esthetic benefits; and to suggest guidelines for the se quence and tim in g o f treatment pro cedures.
Classification of indications INTEGRITY OF THE ARCH. Several conditions, inclu d in g abnormal size or shape of teeth, missing teeth, loss of space, and m alposition of teeth as in in s t a n c e s o f c r o w d in g o r crossbites, w ill upset the integrity of the arch. A lign m en t o f teeth should be evaluated for cusp-to-cusp and marginal ridge-to-m arginal ridge re
lationships. Contour o f the gingiva and s tru c tu re o f a lv e o la r bones should also be assessed. BIOMECHANICS. A fte r trea tm en t, teeth are exposed to and must to ler ate occlusal stresses that occasion a lly can be greater than o rig in a l stresses because of loss o f adjacent te eth or s u p p o rtin g tissu e. B io mechanical factors, such as the ratio o f crown to root and the in c lin a tio n o f teeth, w ill determine the d enti tio n ’s endurance of occlusal stresses and w ill directly affect the longevity o f the result. For instance, u prig h ting tipped molars before construction of a fixed prosthesis better distributes the forces. LIMITATIONS IN DESIGN OF PROS THESIS. O ptim al prosthetic restora tio n requires p a ra lle l abutm ents, p o n tic spaces o f s u ffic ie n t w id th , open embrasures, and a fla t occlusal plane. O rth o d o n tic m ovem ent of teeth may also be needed to avoid pulpal involvem ent o f teeth during restorative preparations, to a llo w an adequate thickness o f restorative ma terial to be placed, or to extrude teeth when crowns are fractured below the gingival attachment.6 If the patient’s fa c ia l s k e le ta l p a tte rn p re v e n ts adequate prosthetic treatment and if it is beyond the scope of orthodontic m ovem ent o f teeth, o rth o g n a th ic surgery may be indicated. ESTHETIC APPEARANCE. C o n s id erations of esthetic appearance that influ en ce the p a tie n t’s self-im age y A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9 ■ 8 2 5
A R T IC L E S
o rth o d o n tic treatm ent can be en hanced by b u ild in g retention into prostheses by restoring coronal con tour and by splinting. Reduction of the number o f appointments for ad justment of retainers and increased comfort of patients are other advan tages o f prosthetic reinforcement of retention.
Clinical examples
F ig 1
■
T o p le f t a n d r ig h t , t w o v ie w s o f m a lo c
c lu s io n s h o w in g c r o w d in g a n d m id lin e d e v ia t io n s . C e n t e r le f t , a r r a n g e m e n t o f te e th a f t e r o r th o d o n tic tr e a tm e n t. A lth o u g h m a n y te e th h a d p r e v io u s ly b e e n e x tr a c te d , a n o th e r e x tr a c tio n in m a x illa r y a r c h w a s n e c e s s a ry to a lig n r e m a in in g t e e t h . P r e m o l a r s p a c e w a s n o t c o m p le t e ly c lo s e d b e c a u s e in t e r d ig it a t io n w a s s a tis fa c to r y a n d p o n t ic c o u ld b e p la c e d . C e n t e r r ig h t , b o t t o m , c o m p le te d f ix e d p r o s th e s is .
and psychological and social func tions may require treatment of dias temas, crow ding, rotation, extrusion, or m igration of teeth. Whereas these conditions can be treated by means of orthodontic movement or restorative methods, a combined orthodonticp ro s th o d o n tic e ffo rt u su a lly p ro duces better results.
anterior and posterior teeth are pos sible when the balance of muscular, occlusal, and eruptive forces is upset. Restoration of tooth structure can be considered as a preventive orthodon tic method. PROSTHETICS AS ORTHODONTIC RE TENTION. In many cases, stability of
A lth ou g h many conditions can be im proved w ith either orthodontic or restorative treatment, a combination o f the tw o disciplines may produce better results in some cases. The examples show many indications for a combined approach. In the patient shown in Figure 1, there are problems of esthetic ap pearance, design of prosthesis, and in te g rity of the arch. She was seeking em ploym ent and th ou gh t her ap pearance was a handicap. Unless teeth were moved, a fixed p artial denture could not be designed to satisfy the demands of esthetic ap pearance and integrity of the arch. S im ilarly, in the patient shown in Figure 2 , there are problems in integ rity o f the arch, esthetic appearance, and biomechanical relationships. Or thodontic treatment was necessary to regain lost space adjacent to a peg shaped lateral incisor and to move the impacted left m axillary canine into the dental arch. A simple ap proach to restoration of misshapen teeth uses composite restorative ma terial to improve esthetic appearance
PERIODONTAL CONSIDERATIONS.
Conditions contributing to periodon tal disease warrant orthodontic and prosthodontic evaluation .7 Correc tion through orthodontic treatment should be considered when changes in alveolar bones are lik e ly to occur, as in the conditions of tipped molars, deep overbite, lim itations of function because o f crossbites, cro w d in g , open contacts that allo w im paction of food, occlusal trauma, and dis crepancies in positions of centric oc clusion and centric relationships. In p e r io d o n ta l tre a tm e n t, p r io r it y should be given to im proving oral hygiene and fa cilita ting periodontal maintenance.
F ig 2
■ T o p le f t , m a lo c c lu s io n c h a r a c t e r iz e d b y
C la s s I I m o la r r e la t io n s h ip , b ila t e r a l b u c c a l c r o s s b ite s o f m a x i l l a r y f i r s t p r e m o la r s , im p a c t io n o f m a x illa r y le f t c a n in e , c o n g e n it a l a b s e n c e o f p e r m a n e n t m a x illa r y le f t la t e r a l in c is o r , a n d p e g g in g o f m a x i l l a r y r i g h t l a t e r a l in c is o r . S e v e r a l p r o b le m s w e r e e n c o u n te r e d d u r in g tr e a t m e n t. T o p r ig h t , a f t e r o r t h o d o n t ic a lig n m e n t , b ite h a s d e e p e n e d b e c a u s e o f im p r o v e d in te r c u s p a tio n a n d r e s u lt n e e d s to b e r e t a in e d . B o t t o m , d r if t in g o f t e m p o r a r y p r o s th e s is c a n b e o b
PREVENTION OF MALOCCLUSION.
s e r v e d a n d r e la p s e o f c o r r e c te d r o t a t io n o f m a x il
M igration and overeruption of both
la r y r ig h t s e c o n d p r e m o la r h a s o c c u rre d .
8 2 6 ■ J A D A , V o l. 99 , N o v e m b e r 1 9 7 9
A R T IC L E S
F ig 3
■ R a d io g r a p h s s h o w e x a m p le o f c h a n g e s
in b o n e a c c o m p a n y in g u p r ig h t in g o f m o la r s in 4 5 - y e a r - o ld w o m a n . B e c a u s e im p r o v e m e n t s in a r c h ite c tu r e o f a lv e o la r b o n e m a y b e e x tr e m e , p e r io d o n t a l s u r g e r y is u s u a lly d e la y e d u n t i l m o v e m e n t o f t e e t h is c o m p le te d .
F ig 4
■ R a d io g r a p h s o f a r e a o f r ig h t m o la r i n 5 6 - y e a r - o ld w o m a n . N o tic e p a r a lle lis m o f a b u tm e n ts
a n d im p r o v e m e n t s i n c o n t o u r o f a lv e o la r b o n e .
F ig 5
■ L e ft, u n d e r s iz e d m a x illa r y la t e r a l in c is o r a f t e r o r t h o d o n t ic m o v e m e n t o f te e th . R ig h t , c o m p o
s it e b u ild u p p la c e d f o r im p r o v e d r e t e n t io n a n d e s th e tic a p p e a r a n c e . C h ip p e d c e n t r a l in c is o r w a s e x t r u d e d f o r s u b s e q u e n t r e c o n to u r in g .
and to m aintain the in te g rity and symmetry of the arch. Ceramometal crowns can be considered later; how ever, in many situations the acidetched composite restoration is pre ferred because it is more esthetically pleasing and is better tolerated by the g in g iv a . The re te n tio n phase o f treatment was deficient as relapse of the premolar rotation may have been prevented by severing the gingival fibers. The lateral pontic moved dur ing a prolonged period o f retention as the occlusion settled. Such move m en t o f a p e rm a n e n t p ro sth e sis placed prematurely w ou ld be unac ceptable. U p r ig h tin g o f a tip p e d d is ta l a b u tm e n t t o o t h c a n im p r o v e biom echanical relationships, solve lim ita tion s of design of prostheses, im p ro v e re te n tio n o f fix e d p ro s theses, and better provide an envi ronm ent for maintenance and heal ing of periodontal tissues. T ra d itio n ally, fixed partial dentures are used in posterior regions for mechanical rather than cosmetic reasons. Use of a fixed partial denture can stop d rift ing o f teeth and pro vid e occlusal support. However, some im portant biom echanical considerations are often neglected when the posterior spaces are restored. D istribution of forces on a tipped abutment creates a m om ent th a t u n fa v o ra b ly directs stress. Acute angles between tipped molars and the alveolar bone co n tri bute to fo rm a tio n o f p e rio d o n ta l pockets and defects in bone (Fig 3,4). U prigh ting alone can im prove the al veolar bone as shown on radiographs and substantiated by p e rio d o n ta l probing. Im proved contour of alveo lar bones after u prig h ting o f molars can even be achieved in 50- or 60year-old patients. A lthough the con struction of fixe d p artial dentures over tipped abutments is possible, or thodontic movement of the tipped molars before prosthetic treatment is a better approach. In addition, m u lti ple u n it fixe d prostheses required parallel abutments to facilitate inser tio n and removal. Restorations and prostheses may act as orthodontic retainers (Fig 5-7} or as preventive orthodontic a p p li ances (Fig 8). O rthodontic treatment can be fo llo w e d b y a s im p le , n o n in va sive te chn iqu e to ensure preservation of integ rity of the arch, especially when conventional fixed
E v a n s - N a th a n s o n : O R T H O D O N T IC -P R O S T H O D O N T IC C O L L A B O R A T IO N ■ 8 2 7
F ig 6
■ T o p , la b ia l v ie w o f d e n titio n o f 1 2 -y e a r-
o ld b o y . S p a c e f o r c o n g e n it a lly a b s e n t la t e r a l i n c is o r s h a s b e e n r e g a in e d w i t h u s e o f o r t h o d o n t ic a p p lia n c e s . B o t t o m , t w o v ie w s o f a c id - e tc h e d c o m p o s ite p a r t ia l p r o s th e s is . P r o s th e s is w a s p la c e d a f t e r p a t ie n t lo s t r e m o v a b le r e t a in e r m a n y t im e s .
F ig 7
■ L e f t , m a x illa r y m id lin e d ia s te m a i n y o u n g g ir l. R ig h t , m a x illa r y c e n t r a l in c is o r s s p lin t e d to
g e t h e r w i t h w i r e a n d c o m p o s ite s p lin t a f t e r o r t h o d o n t ic c lo s u r e o f m id lin e d ia s te m a .
F ig 8
■ D r if t in g o f m a n d ib u la r a n te r io r te e th
a l t e r lo s s o f g u id a n c e o f m a x i l l a r y in c is o r s . P r o p e r ly c o n to u r e d r e s t o r a t io n c a n e f fe c tiv e ly p r e v e n t d r iftin g o f te e th th a t o c c u rs a fte r c h a n g e in c o n ta c ts o r fu n c tio n . A lth o u g h tip p in g o f p o s t e r io r te e th in t o e x t r a c t io n s p a c e s is w e ll d o c u m e n te d , s im ila r c h a n g e s c a n o c c u r in a n te r io r r e g io n o f t h e m o u t h . I n e x a m p le s , d r if t in g o f m a n d ib u la r in c is o r s p r e v e n ts r e s to r a tio n o f m a x illa r y te e th .
8 2 8 ■ J A D A , V o l. 99 , N o v e m b e r 1 9 7 9
prosthodontic treatment is not in d i cated because of the patient’s age or economic situation. In Figure 5, the size of a m axillary lateral incisor was increased w ith composite resin to close spaces and to m aintain the po sition of the other m axillary anterior teeth. In Figure 6, plastic pontic units w ith retention slots were placed in the regained spaces of the lateral in cisor and were bonded to the enamel of the adjacent teeth w ith acid-etch resin and composite resin. Such con structions combine the esthetic and functional benefits w ith preservation of integ rity of the arch and allo w for the postponement of a trad ition al fixed p artial denture. In Figure 7, closure o f a median diastema was re tained w ith a s p lin t made o f compos ite resin and wire. Proper occlusal and interdental contacts are neces sary for sta bility o f position of teeth (Fig 8). Early replacem ent o f lost structure is indicated to prevent u n desired changes in position of teeth.
Specific recommendations Movement of teeth should be started after inflam m ation of the periodon tiu m has been reduced and after cooperation o f the patient has been assured. Thus, movement of teeth comes after oral hygiene instruction, sca lin g, ro o t p la n in g , c o n tro l of caries, endodontic treatment, extrac tions, and, i f possible, establishment of centric relationships. Space is a prerequisite for movement of teeth and can be created by stripping, ex traction, or, in lim ite d instances, by e x p a n s io n o f th e a rc h . D u rin g m o v e m e n t o f te e th , p e rio d o n ta l maintenance should be guarded by thorough care at home and more fre quent oral prophylaxis. Movement of teeth should precede elim ination of periodontal pockets and occlusal ad justment and should precede proce dures of prosthetic stabilization and retention because movement of teeth may m o d ify g in g iva l and osseous morphology. Retention o f teeth moved w ith or thodontic prostheses is 3 complex and im portant issue in oral recon struction. Generally, best results are obtained when prosthetic treatment is started after adequate retention is achieved and w hen m in im a l relapse is expected. A fter orthodontic treat ment, m in or changes in positions of
A R T IC L E S
teeth occur as the occlusion settles. Some retention can be incorporated into orthodontic treatment through restoration o f norm al contour to pos te rio r teeth that w ill ensure norm al intercuspation. Problems, such as u n dersized lateral incisors, should pro bably be considered after movement o f te e th . A n a c id -e tc h co m p o s ite b u ild u p o f an undersized tooth can be im m ediately placed i f bonded brackets have been used during or thodontic treatment and i f spaces are closed. If teeth were banded, inter d e n ta l spaces s h o u ld be closed q u ic k ly and p o sitio n o f the sm all tooth should be m aintained before increasing the size o f the underde veloped tooth. A ttainm ent o f normal shape and size o f a to o th , a fte r movement of teeth, functions as a re tainer, as does selective postorthodontic g rin d in g to elim inate inter ferences. Occlusion and tooth mass should be used as retentive devices as often as possible. Surgical transec tio n of g in giva l fibers can reduce ro tational relapse and should be done before rem oval o f the orthodontic prosthesis.8 Also, excessively com pressed tissue, w h ich sometimes re mains after closure o f an extraction space, should be excised. In adults, long periods o f retention may be im practical. If crow n prepara tions are started im m ediately after or th o d o n tic trea tm e n t, m o b ility o f teeth and greater than usual sensitiv ity to reduction of teeth can be ex pected. A settling or recovery tim e makes reduction more comfortable. A fter orthognathic surgery, an adap tive period o f several m onths may be needed before a perm anent pros thesis is placed. The choice o f fixed retention or removable retention may be dependent on age o f the patient because placement of a fixed partial denture in the anterior region may not be possible i f the p u lp chambers are large. Either a removable retainer or composite s p lin t may be placed for th e needed re te n tio n p e rio d in youngsters; th is depends on the re lia b ility o f the patient to wear a re movable retainer. In constructing a H awley retainer w ith a labial w ire that contacts a tooth restored w ith composite resin, a short piece of Tef lon or plastic catheter tubing should be slipped over the arch w ire during co nstructio n . A m etal stain on a composite restoration, caused by in
sertion and rem oval o f the retainer, is thereby avoided. Insertion o f a fixed prosthesis is subject to the fo llo w in g cautions: —Provisional s p lin t units should cover the entire length of the pre pared teeth and should not leave den tin exposed. — Temporary splints m ust fit w e ll and re lin in g o f the s p lin t may be needed to achieve a better fit. — Tem porary sp lin ts m ust have good occlusal contacts to prevent buccolingual d rift. — In the case o f a cantilever pros thesis, the pontic u n it should contact a broad surface o f an unrestored adja cent tooth. —Impressions should be made tw o or three weeks after preparation so that teeth can settle under the tem po rary sphnt. — To m in im ize the effects of con tinued changes in position o f teeth, dental laboratory procedures must be done in the shortest possible tim e and appointments should be sched uled as soon as possible after impres sions are made. —Patients should be to ld to return im m ediately for recementation i f the te m p o ra ry s p lin t s h o u ld fa il or loosen. —When the fin a l restoration does not seat com pletely (a discrepancy of a h a lf m illim e te r, or less) and occlu sion permits, it can be cemented w ith a less rig id tem porary cement. — P e rm a n e n t c e m e n ta tio n is norm ally delayed u n til the position o f the abutments is to ta lly stable. Long periods of temporary cementa tio n o f a permanent prosthesis may be required.
Discussion Goals o f o rth o d o n tic treatm ent in oral rehabilitation may d iffer from the usual objectives of orthodontic treatm ent o f young people. Some conditions that ro u tin e ly w ou ld be treated in a youngster may be u n treated in a middle-aged person who has healthy alveolar bone. Thus, ana tom ic criteria such as A ngle’s clas sification and a conceptual ideal ar rangement of teeth do not adequately describe the functional requirements o f a satisfactory outcome o f treat ment. It is not assumed that the per son w ill have better function i f the dentition conforms to A ngle’s stan
dard. It has long been recognized and summarized in a state-of-the-art pub lic a tio n on dental occlusion that, “ considerable variation in occlusal relationships n o rm a lly exists, and most o f th is variation has not been causatively related to diseases or de structive states.” 9 It is im portant to evaluate m alpositioned teeth relative to adjacent teeth in the same arch and to the opposing dental u nits in cen tric relation. Other factors, such as oral hygiene, stress, in te g rity of the arch, and age of the patient, influence the dental environment. In regard to the potential benefits to the patient, movement o f teeth in adults has been unw isely discour aged by both prosthodontists and orth o d o n tis ts . D e n tis ts h ave to o h ea vily re lie d on prostheses, con structing partial dentures in Class III m a lo c c lu s io n s , fa b ric a tin g fix e d prostheses w hen buccal crossbites exist, and extracting impacted teeth that could be moved into the arch. Dentists w ho use restorative proce dures should be more aware o f the fe a s ib ility o f im p ro v in g occlusion through orthodontic-prosthodontic treatment and, possibly, through or thognathic surgical means. Problems such as skeletal disharmonies, exces sive show o f m axillary gingiva, lack of teeth for orthodontic anchorage, or refusal o f the p atie nt to w ear or th o d o n tic appliances m ay require collaboration from the d iscip lin e of oral surgery in regard to orthognathic surgery. Orthodontists may fin d that adults are d iffic u lt patients though move ment o f teeth is feasible. A d u lt pa tie n ts d iffe r d e c id e d ly fro m the younger patients w ho have tra d i tio n a lly been treated by orthodon tis ts . A d u lts are concerned w ith esthetic appearance d u rin g tre a t m ent and consequently can be anx ious or uncooperative. They may focus on one aspect o f a malocclusion and demand that o nly w hat they con sider the chief problem be corrected. O fte n , tre a tm e n t is l im it e d or changed because o f lack o f growth. Teeth may move slow ly in adult pa tients; leveling o f the occlusal plane or change in m olar position may be less spontaneous because o f lack of eruption of teeth. A d u lts are con cerned more about pain and altered fu nctio n because o f changes in oc clusion than are the young patients
E v a n g -N a th a n s o n : O R T H O D O N T IC - P R O S T H O D O N T IC C O L L A B O R A T IO N ■ 8 2 9
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w ho a void the sensitive areas of shedding deciduous teeth and erupt ing permanent teeth. Previous con tacts w ith dentistry may have been unsatisfactory or unpleasant. A dults are more lik e ly to have missing teeth, large restorations, p a in fu l areas in the m outh, loss o f bone, unhealthy supporting tissues, and an apprehen sion of dental treatment. In many adults, orthodontic treatment is d i rected at problems of rehabilitation caused by neglect or insu fficien t den tal care. Treatment often requires col laboration and frequent comm unica tio n w ith other dental practitioners s u c h as p e r io d o n tis ts , p r o s th odontists, endodontists, and oral surgeons. O rthodontists should be educated about adult problems. They should look more closely at tooth-totooth contacts as the postorthodontic occlusion is notoriously deficient in regard to the local fu n c tio n a l re q u ire m e n ts o f the d e n titio n .10,11 Also, orthodontists could use com posite restorative m aterials more
often in the retention phases o f or thodontic treatment.
O r th o d 7 2 ( l) :8 5 - 9 2 ,1 9 7 7 . 3 . B a e r , P .N ., a n d M o r r is , J .L . T e x t b o o k o f
Summary
p e r io d o n tic s . P h ila d e lp h ia , J. B . L ip p in c o t t C o ., 1 9 7 7 ,p 18 5 .
In dental practice, combined plans of o r th o d o n tic a nd p ro s th o d o n tic treatment are underused. Indications fo r a co lla bo ra tive e ffo rt in c lu d e preservation of integ rity o f the dental arch, biomechanical factors, lim ita tions in design o f prostheses, esthetic appearance, p e rio d o n ta l c o n s id erations, p re ven tion o f m a lo cclu sion, and better retention of position of teeth.
4 . S c h lu g e r , S .; Y o u d e lis , R .A .; a n d
Page,
R . C . P e r i o d o n t a l d is e a s e s . P h i l a d e l p h i a , L e a & F e b ig e r , 1 9 7 7 , p 6 1 2 . 5 . H o o d , J . A . A . ; F a r a h , J .W .; a n d C r a ig , R .G . M o d ific a tio n
o f s tre s s e s in
a lv e o la r b o n e in
d uced
t ilte d
J P ro s th e t D e n t
b y
a
m o la r .
3 4 (4 ):4 1 5 -4 2 1 , 1 9 7 5 . 6 . In g b e r , J .S . F o r c e d e r u p t io n . A m e t h o d o f t r e a t in g
n o n r e s to r a b le te e th — p e r io d o n t a l a n d
r e s to r a tiv e
c o n s id e r a t io n s .
J P e r io d o n to l
4 7 (4 ):2 0 3 -2 1 6 , 1 9 7 6 . 7 . B r o w n , I.S . T h e e ffe c t o f o r th o d o n tic th e r a p y o n c e r t a in ty p e s o f p e r io d o n ta l d e fe c ts . J P e r io d o n to l 4 4 { 1 2 ) :7 4 2 - 7 5 6 ,1 9 7 3 . 8 . K a p la n ,
R .G .
S u p r a c r e s ta l fib e r o to m y .
J A D A 9 5 (5 ):1 1 2 7 -1 1 3 2 ,1 9 7 7 . D r . E v a n s is a s s is ta n t p r o fe s s o r , d e p a r tm e n t o f o r th o d o n tic s , H a r v a r d
S c h o o l o f D e n ta l
9 . Is a a c s o n , R .J ., a n d o th e r s . R e s e a r c h o n v a r ia t io n i n d e n ta l o c c lu s io n . A
“ s ta te -o f-th e -a rt”
M e d ic in e . D r . N a t h a n s o n is a s s o c ia t e p r o f e s s o r ,
w o rk s h o p
d e p a r tm e n t o f r e s to r a tiv e d e n t is t r y , a n d is h e a d ,
A n o m a lie s P r o g r a m , N a tio n a l In s t it u t e o f D e n
d iv is io n o f o p e r a tiv e d e n t is t r y , S c h o o l o f D e n ta l
ta l R e s e a rc h . A m J O rth o d 6 8 (3 ):2 4 1 -2 5 5 ,1 9 7 5 .
M e d ic in e , T u f t s U n iv e r s it y . A d d r e s s r e q u e s ts
c o n d u c te d
1 0 . S c h lu g e r , S . T h e
f o r r e p r in t s t o D r . E v a n s , A s s is ta n t P r o fe s s o r o f
p o s to r th o d o n tic
O r th o d o n t ic s , H a r v a r d
5 2 5 -5 2 7 , 1 9 6 8 .
S c h o o l o f D e n ta l
M e d ic in e , 1 8 8 L o n g w o o d A v e , B o s to n , 0 2 1 1 5 . 1.
B a r r e r , H .G . T h e a d u lt o r t h o d o n t ic p a tie n t.
b y
th e
C r a n io fa c ia l
p e r io d o n tis t a n d
p a tie n t. D e n t C lin
N
th e
A m e r
1 1 . W illia m s , R . L . O c c lu s a l t r e a t m e n t f o r th e p o s to r th o d o n tic
A m J O rth o d 7 2 (7 ):6 1 7 -6 4 0 ,1 9 7 7 .
8 3 0 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
2 . T u r p in , D .L . L o n g R a n g e S tu d y C o m m it te e r e le a s e s r e s u lt s o f m a n p o w e r s u r v e y . A m J
5 9 (5 ):4 3 1 -4 4 2 , 1 9 7 2 .
p a tie n t.
A m
J O rth o d
In d ic a tio n s f o r o r th o d o n tic -p r o s th o d o n tic c o lla b o r a tio n in d e n ta l tre a tm e n t C a ria A . Evans, DDS, D M S c D a n N a th a n s o n , D M D
A com bined orthodontic-prosthodontic approach g re a tly benefits p atients needing comprehensive d ental care. Im provem ents in fu nction, o ra l health, and esthetic appearance can be re a liz e d by a p p ro p ria te ly p la n n in g the sequence and the tim in g o f treatm ent procedures.
A JL I s the p ub lic becomes more con cerned about long-term dental health and preservation o f natural d en ti tion, patients more re a d ily accept complex plans of treatment that are directed at establishing optim al oc clusion and integ rity of the dental arch. Coordinated programs o f or thodontic and prosthodontic treat ment have recently become more fre quent, especially as use of orthodon tic appliances by adults has become socially accepted .1 A survey of or th o d o n tis ts p u b lis h e d in 1977 sh o w e d th a t a d u lt p a tie n ts ac counted for more than 10 % of the pa tients in approxim ately h a lf of the or th o d o n tic practices .2 O rth od on tic appliances are also used in the treat ment o f adults by periodontists and dentists perform ing restorative pro cedures. Nevertheless, more patients c o u ld b e n e fit fro m c o o rd in a te d prosthodontic-orthodontic treatment after benefits of this approach be come better known. In coordinating orthodontic and prosthodontic treatment plans, restor a tio n o f n o rm a l fu n c t io n and achievement o f a nonpathogenic dis tribu tion of occlusal forces are key objectives. A lthough occlusal aberra tions alone do not cause periodontal
disease, the co m bination o f local b a c te ria l ir r ita n ts and o c c lu s a l trauma may lead to progressive de struction o f bone .3,4 M alpositioned teeth are more d iffic u lt to clean and are associated w ith an altered d is tri bution o f stress in the alveolar bone and periodontal ligam ent, such as around tipped m olars .5 Several categories o f collaboration of o rth o d o n tic and pro stho d on tic treatment w ill be described to em phasize the importance of a carefully planned approach to the patie nt’s needs o f com prehensive care; to demonstrate possible periodontal, biomechanical, and esthetic benefits; and to suggest guidelines for the se quence and tim in g o f treatment pro cedures.
Classification of indications INTEGRITY OF THE ARCH. Several conditions, inclu d in g abnormal size or shape of teeth, missing teeth, loss of space, and m alposition of teeth as in in s t a n c e s o f c r o w d in g o r crossbites, w ill upset the integrity of the arch. A lign m en t o f teeth should be evaluated for cusp-to-cusp and marginal ridge-to-m arginal ridge re
lationships. Contour o f the gingiva and s tru c tu re o f a lv e o la r bones should also be assessed. BIOMECHANICS. A fte r trea tm en t, teeth are exposed to and must to ler ate occlusal stresses that occasion a lly can be greater than o rig in a l stresses because of loss o f adjacent te eth or s u p p o rtin g tissu e. B io mechanical factors, such as the ratio o f crown to root and the in c lin a tio n o f teeth, w ill determine the d enti tio n ’s endurance of occlusal stresses and w ill directly affect the longevity o f the result. For instance, u prig h ting tipped molars before construction of a fixed prosthesis better distributes the forces. LIMITATIONS IN DESIGN OF PROS THESIS. O ptim al prosthetic restora tio n requires p a ra lle l abutm ents, p o n tic spaces o f s u ffic ie n t w id th , open embrasures, and a fla t occlusal plane. O rth o d o n tic m ovem ent of teeth may also be needed to avoid pulpal involvem ent o f teeth during restorative preparations, to a llo w an adequate thickness o f restorative ma terial to be placed, or to extrude teeth when crowns are fractured below the gingival attachment.6 If the patient’s fa c ia l s k e le ta l p a tte rn p re v e n ts adequate prosthetic treatment and if it is beyond the scope of orthodontic m ovem ent o f teeth, o rth o g n a th ic surgery may be indicated. ESTHETIC APPEARANCE. C o n s id erations of esthetic appearance that influ en ce the p a tie n t’s self-im age y A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9 ■ 8 2 5
A R T IC L E S
o rth o d o n tic treatm ent can be en hanced by b u ild in g retention into prostheses by restoring coronal con tour and by splinting. Reduction of the number o f appointments for ad justment of retainers and increased comfort of patients are other advan tages o f prosthetic reinforcement of retention.
Clinical examples
F ig 1
■
T o p le f t a n d r ig h t , t w o v ie w s o f m a lo c
c lu s io n s h o w in g c r o w d in g a n d m id lin e d e v ia t io n s . C e n t e r le f t , a r r a n g e m e n t o f te e th a f t e r o r th o d o n tic tr e a tm e n t. A lth o u g h m a n y te e th h a d p r e v io u s ly b e e n e x tr a c te d , a n o th e r e x tr a c tio n in m a x illa r y a r c h w a s n e c e s s a ry to a lig n r e m a in in g t e e t h . P r e m o l a r s p a c e w a s n o t c o m p le t e ly c lo s e d b e c a u s e in t e r d ig it a t io n w a s s a tis fa c to r y a n d p o n t ic c o u ld b e p la c e d . C e n t e r r ig h t , b o t t o m , c o m p le te d f ix e d p r o s th e s is .
and psychological and social func tions may require treatment of dias temas, crow ding, rotation, extrusion, or m igration of teeth. Whereas these conditions can be treated by means of orthodontic movement or restorative methods, a combined orthodonticp ro s th o d o n tic e ffo rt u su a lly p ro duces better results.
anterior and posterior teeth are pos sible when the balance of muscular, occlusal, and eruptive forces is upset. Restoration of tooth structure can be considered as a preventive orthodon tic method. PROSTHETICS AS ORTHODONTIC RE TENTION. In many cases, stability of
A lth ou g h many conditions can be im proved w ith either orthodontic or restorative treatment, a combination o f the tw o disciplines may produce better results in some cases. The examples show many indications for a combined approach. In the patient shown in Figure 1, there are problems of esthetic ap pearance, design of prosthesis, and in te g rity of the arch. She was seeking em ploym ent and th ou gh t her ap pearance was a handicap. Unless teeth were moved, a fixed p artial denture could not be designed to satisfy the demands of esthetic ap pearance and integrity of the arch. S im ilarly, in the patient shown in Figure 2 , there are problems in integ rity o f the arch, esthetic appearance, and biomechanical relationships. Or thodontic treatment was necessary to regain lost space adjacent to a peg shaped lateral incisor and to move the impacted left m axillary canine into the dental arch. A simple ap proach to restoration of misshapen teeth uses composite restorative ma terial to improve esthetic appearance
PERIODONTAL CONSIDERATIONS.
Conditions contributing to periodon tal disease warrant orthodontic and prosthodontic evaluation .7 Correc tion through orthodontic treatment should be considered when changes in alveolar bones are lik e ly to occur, as in the conditions of tipped molars, deep overbite, lim itations of function because o f crossbites, cro w d in g , open contacts that allo w im paction of food, occlusal trauma, and dis crepancies in positions of centric oc clusion and centric relationships. In p e r io d o n ta l tre a tm e n t, p r io r it y should be given to im proving oral hygiene and fa cilita ting periodontal maintenance.
F ig 2
■ T o p le f t , m a lo c c lu s io n c h a r a c t e r iz e d b y
C la s s I I m o la r r e la t io n s h ip , b ila t e r a l b u c c a l c r o s s b ite s o f m a x i l l a r y f i r s t p r e m o la r s , im p a c t io n o f m a x illa r y le f t c a n in e , c o n g e n it a l a b s e n c e o f p e r m a n e n t m a x illa r y le f t la t e r a l in c is o r , a n d p e g g in g o f m a x i l l a r y r i g h t l a t e r a l in c is o r . S e v e r a l p r o b le m s w e r e e n c o u n te r e d d u r in g tr e a t m e n t. T o p r ig h t , a f t e r o r t h o d o n t ic a lig n m e n t , b ite h a s d e e p e n e d b e c a u s e o f im p r o v e d in te r c u s p a tio n a n d r e s u lt n e e d s to b e r e t a in e d . B o t t o m , d r if t in g o f t e m p o r a r y p r o s th e s is c a n b e o b
PREVENTION OF MALOCCLUSION.
s e r v e d a n d r e la p s e o f c o r r e c te d r o t a t io n o f m a x il
M igration and overeruption of both
la r y r ig h t s e c o n d p r e m o la r h a s o c c u rre d .
8 2 6 ■ J A D A , V o l. 99 , N o v e m b e r 1 9 7 9
A R T IC L E S
F ig 3
■ R a d io g r a p h s s h o w e x a m p le o f c h a n g e s
in b o n e a c c o m p a n y in g u p r ig h t in g o f m o la r s in 4 5 - y e a r - o ld w o m a n . B e c a u s e im p r o v e m e n t s in a r c h ite c tu r e o f a lv e o la r b o n e m a y b e e x tr e m e , p e r io d o n t a l s u r g e r y is u s u a lly d e la y e d u n t i l m o v e m e n t o f t e e t h is c o m p le te d .
F ig 4
■ R a d io g r a p h s o f a r e a o f r ig h t m o la r i n 5 6 - y e a r - o ld w o m a n . N o tic e p a r a lle lis m o f a b u tm e n ts
a n d im p r o v e m e n t s i n c o n t o u r o f a lv e o la r b o n e .
F ig 5
■ L e ft, u n d e r s iz e d m a x illa r y la t e r a l in c is o r a f t e r o r t h o d o n t ic m o v e m e n t o f te e th . R ig h t , c o m p o
s it e b u ild u p p la c e d f o r im p r o v e d r e t e n t io n a n d e s th e tic a p p e a r a n c e . C h ip p e d c e n t r a l in c is o r w a s e x t r u d e d f o r s u b s e q u e n t r e c o n to u r in g .
and to m aintain the in te g rity and symmetry of the arch. Ceramometal crowns can be considered later; how ever, in many situations the acidetched composite restoration is pre ferred because it is more esthetically pleasing and is better tolerated by the g in g iv a . The re te n tio n phase o f treatment was deficient as relapse of the premolar rotation may have been prevented by severing the gingival fibers. The lateral pontic moved dur ing a prolonged period o f retention as the occlusion settled. Such move m en t o f a p e rm a n e n t p ro sth e sis placed prematurely w ou ld be unac ceptable. U p r ig h tin g o f a tip p e d d is ta l a b u tm e n t t o o t h c a n im p r o v e biom echanical relationships, solve lim ita tion s of design of prostheses, im p ro v e re te n tio n o f fix e d p ro s theses, and better provide an envi ronm ent for maintenance and heal ing of periodontal tissues. T ra d itio n ally, fixed partial dentures are used in posterior regions for mechanical rather than cosmetic reasons. Use of a fixed partial denture can stop d rift ing o f teeth and pro vid e occlusal support. However, some im portant biom echanical considerations are often neglected when the posterior spaces are restored. D istribution of forces on a tipped abutment creates a m om ent th a t u n fa v o ra b ly directs stress. Acute angles between tipped molars and the alveolar bone co n tri bute to fo rm a tio n o f p e rio d o n ta l pockets and defects in bone (Fig 3,4). U prigh ting alone can im prove the al veolar bone as shown on radiographs and substantiated by p e rio d o n ta l probing. Im proved contour of alveo lar bones after u prig h ting o f molars can even be achieved in 50- or 60year-old patients. A lthough the con struction of fixe d p artial dentures over tipped abutments is possible, or thodontic movement of the tipped molars before prosthetic treatment is a better approach. In addition, m u lti ple u n it fixe d prostheses required parallel abutments to facilitate inser tio n and removal. Restorations and prostheses may act as orthodontic retainers (Fig 5-7} or as preventive orthodontic a p p li ances (Fig 8). O rthodontic treatment can be fo llo w e d b y a s im p le , n o n in va sive te chn iqu e to ensure preservation of integ rity of the arch, especially when conventional fixed
E v a n s - N a th a n s o n : O R T H O D O N T IC -P R O S T H O D O N T IC C O L L A B O R A T IO N ■ 8 2 7
F ig 6
■ T o p , la b ia l v ie w o f d e n titio n o f 1 2 -y e a r-
o ld b o y . S p a c e f o r c o n g e n it a lly a b s e n t la t e r a l i n c is o r s h a s b e e n r e g a in e d w i t h u s e o f o r t h o d o n t ic a p p lia n c e s . B o t t o m , t w o v ie w s o f a c id - e tc h e d c o m p o s ite p a r t ia l p r o s th e s is . P r o s th e s is w a s p la c e d a f t e r p a t ie n t lo s t r e m o v a b le r e t a in e r m a n y t im e s .
F ig 7
■ L e f t , m a x illa r y m id lin e d ia s te m a i n y o u n g g ir l. R ig h t , m a x illa r y c e n t r a l in c is o r s s p lin t e d to
g e t h e r w i t h w i r e a n d c o m p o s ite s p lin t a f t e r o r t h o d o n t ic c lo s u r e o f m id lin e d ia s te m a .
F ig 8
■ D r if t in g o f m a n d ib u la r a n te r io r te e th
a l t e r lo s s o f g u id a n c e o f m a x i l l a r y in c is o r s . P r o p e r ly c o n to u r e d r e s t o r a t io n c a n e f fe c tiv e ly p r e v e n t d r iftin g o f te e th th a t o c c u rs a fte r c h a n g e in c o n ta c ts o r fu n c tio n . A lth o u g h tip p in g o f p o s t e r io r te e th in t o e x t r a c t io n s p a c e s is w e ll d o c u m e n te d , s im ila r c h a n g e s c a n o c c u r in a n te r io r r e g io n o f t h e m o u t h . I n e x a m p le s , d r if t in g o f m a n d ib u la r in c is o r s p r e v e n ts r e s to r a tio n o f m a x illa r y te e th .
8 2 8 ■ J A D A , V o l. 99 , N o v e m b e r 1 9 7 9
prosthodontic treatment is not in d i cated because of the patient’s age or economic situation. In Figure 5, the size of a m axillary lateral incisor was increased w ith composite resin to close spaces and to m aintain the po sition of the other m axillary anterior teeth. In Figure 6, plastic pontic units w ith retention slots were placed in the regained spaces of the lateral in cisor and were bonded to the enamel of the adjacent teeth w ith acid-etch resin and composite resin. Such con structions combine the esthetic and functional benefits w ith preservation of integ rity of the arch and allo w for the postponement of a trad ition al fixed p artial denture. In Figure 7, closure o f a median diastema was re tained w ith a s p lin t made o f compos ite resin and wire. Proper occlusal and interdental contacts are neces sary for sta bility o f position of teeth (Fig 8). Early replacem ent o f lost structure is indicated to prevent u n desired changes in position of teeth.
Specific recommendations Movement of teeth should be started after inflam m ation of the periodon tiu m has been reduced and after cooperation o f the patient has been assured. Thus, movement of teeth comes after oral hygiene instruction, sca lin g, ro o t p la n in g , c o n tro l of caries, endodontic treatment, extrac tions, and, i f possible, establishment of centric relationships. Space is a prerequisite for movement of teeth and can be created by stripping, ex traction, or, in lim ite d instances, by e x p a n s io n o f th e a rc h . D u rin g m o v e m e n t o f te e th , p e rio d o n ta l maintenance should be guarded by thorough care at home and more fre quent oral prophylaxis. Movement of teeth should precede elim ination of periodontal pockets and occlusal ad justment and should precede proce dures of prosthetic stabilization and retention because movement of teeth may m o d ify g in g iva l and osseous morphology. Retention o f teeth moved w ith or thodontic prostheses is 3 complex and im portant issue in oral recon struction. Generally, best results are obtained when prosthetic treatment is started after adequate retention is achieved and w hen m in im a l relapse is expected. A fter orthodontic treat ment, m in or changes in positions of
A R T IC L E S
teeth occur as the occlusion settles. Some retention can be incorporated into orthodontic treatment through restoration o f norm al contour to pos te rio r teeth that w ill ensure norm al intercuspation. Problems, such as u n dersized lateral incisors, should pro bably be considered after movement o f te e th . A n a c id -e tc h co m p o s ite b u ild u p o f an undersized tooth can be im m ediately placed i f bonded brackets have been used during or thodontic treatment and i f spaces are closed. If teeth were banded, inter d e n ta l spaces s h o u ld be closed q u ic k ly and p o sitio n o f the sm all tooth should be m aintained before increasing the size o f the underde veloped tooth. A ttainm ent o f normal shape and size o f a to o th , a fte r movement of teeth, functions as a re tainer, as does selective postorthodontic g rin d in g to elim inate inter ferences. Occlusion and tooth mass should be used as retentive devices as often as possible. Surgical transec tio n of g in giva l fibers can reduce ro tational relapse and should be done before rem oval o f the orthodontic prosthesis.8 Also, excessively com pressed tissue, w h ich sometimes re mains after closure o f an extraction space, should be excised. In adults, long periods o f retention may be im practical. If crow n prepara tions are started im m ediately after or th o d o n tic trea tm e n t, m o b ility o f teeth and greater than usual sensitiv ity to reduction of teeth can be ex pected. A settling or recovery tim e makes reduction more comfortable. A fter orthognathic surgery, an adap tive period o f several m onths may be needed before a perm anent pros thesis is placed. The choice o f fixed retention or removable retention may be dependent on age o f the patient because placement of a fixed partial denture in the anterior region may not be possible i f the p u lp chambers are large. Either a removable retainer or composite s p lin t may be placed for th e needed re te n tio n p e rio d in youngsters; th is depends on the re lia b ility o f the patient to wear a re movable retainer. In constructing a H awley retainer w ith a labial w ire that contacts a tooth restored w ith composite resin, a short piece of Tef lon or plastic catheter tubing should be slipped over the arch w ire during co nstructio n . A m etal stain on a composite restoration, caused by in
sertion and rem oval o f the retainer, is thereby avoided. Insertion o f a fixed prosthesis is subject to the fo llo w in g cautions: —Provisional s p lin t units should cover the entire length of the pre pared teeth and should not leave den tin exposed. — Temporary splints m ust fit w e ll and re lin in g o f the s p lin t may be needed to achieve a better fit. — Tem porary sp lin ts m ust have good occlusal contacts to prevent buccolingual d rift. — In the case o f a cantilever pros thesis, the pontic u n it should contact a broad surface o f an unrestored adja cent tooth. —Impressions should be made tw o or three weeks after preparation so that teeth can settle under the tem po rary sphnt. — To m in im ize the effects of con tinued changes in position o f teeth, dental laboratory procedures must be done in the shortest possible tim e and appointments should be sched uled as soon as possible after impres sions are made. —Patients should be to ld to return im m ediately for recementation i f the te m p o ra ry s p lin t s h o u ld fa il or loosen. —When the fin a l restoration does not seat com pletely (a discrepancy of a h a lf m illim e te r, or less) and occlu sion permits, it can be cemented w ith a less rig id tem porary cement. — P e rm a n e n t c e m e n ta tio n is norm ally delayed u n til the position o f the abutments is to ta lly stable. Long periods of temporary cementa tio n o f a permanent prosthesis may be required.
Discussion Goals o f o rth o d o n tic treatm ent in oral rehabilitation may d iffer from the usual objectives of orthodontic treatm ent o f young people. Some conditions that ro u tin e ly w ou ld be treated in a youngster may be u n treated in a middle-aged person who has healthy alveolar bone. Thus, ana tom ic criteria such as A ngle’s clas sification and a conceptual ideal ar rangement of teeth do not adequately describe the functional requirements o f a satisfactory outcome o f treat ment. It is not assumed that the per son w ill have better function i f the dentition conforms to A ngle’s stan
dard. It has long been recognized and summarized in a state-of-the-art pub lic a tio n on dental occlusion that, “ considerable variation in occlusal relationships n o rm a lly exists, and most o f th is variation has not been causatively related to diseases or de structive states.” 9 It is im portant to evaluate m alpositioned teeth relative to adjacent teeth in the same arch and to the opposing dental u nits in cen tric relation. Other factors, such as oral hygiene, stress, in te g rity of the arch, and age of the patient, influence the dental environment. In regard to the potential benefits to the patient, movement o f teeth in adults has been unw isely discour aged by both prosthodontists and orth o d o n tis ts . D e n tis ts h ave to o h ea vily re lie d on prostheses, con structing partial dentures in Class III m a lo c c lu s io n s , fa b ric a tin g fix e d prostheses w hen buccal crossbites exist, and extracting impacted teeth that could be moved into the arch. Dentists w ho use restorative proce dures should be more aware o f the fe a s ib ility o f im p ro v in g occlusion through orthodontic-prosthodontic treatment and, possibly, through or thognathic surgical means. Problems such as skeletal disharmonies, exces sive show o f m axillary gingiva, lack of teeth for orthodontic anchorage, or refusal o f the p atie nt to w ear or th o d o n tic appliances m ay require collaboration from the d iscip lin e of oral surgery in regard to orthognathic surgery. Orthodontists may fin d that adults are d iffic u lt patients though move ment o f teeth is feasible. A d u lt pa tie n ts d iffe r d e c id e d ly fro m the younger patients w ho have tra d i tio n a lly been treated by orthodon tis ts . A d u lts are concerned w ith esthetic appearance d u rin g tre a t m ent and consequently can be anx ious or uncooperative. They may focus on one aspect o f a malocclusion and demand that o nly w hat they con sider the chief problem be corrected. O fte n , tre a tm e n t is l im it e d or changed because o f lack o f growth. Teeth may move slow ly in adult pa tients; leveling o f the occlusal plane or change in m olar position may be less spontaneous because o f lack of eruption of teeth. A d u lts are con cerned more about pain and altered fu nctio n because o f changes in oc clusion than are the young patients
E v a n g -N a th a n s o n : O R T H O D O N T IC - P R O S T H O D O N T IC C O L L A B O R A T IO N ■ 8 2 9
A R T IC L E S
w ho a void the sensitive areas of shedding deciduous teeth and erupt ing permanent teeth. Previous con tacts w ith dentistry may have been unsatisfactory or unpleasant. A dults are more lik e ly to have missing teeth, large restorations, p a in fu l areas in the m outh, loss o f bone, unhealthy supporting tissues, and an apprehen sion of dental treatment. In many adults, orthodontic treatment is d i rected at problems of rehabilitation caused by neglect or insu fficien t den tal care. Treatment often requires col laboration and frequent comm unica tio n w ith other dental practitioners s u c h as p e r io d o n tis ts , p r o s th odontists, endodontists, and oral surgeons. O rthodontists should be educated about adult problems. They should look more closely at tooth-totooth contacts as the postorthodontic occlusion is notoriously deficient in regard to the local fu n c tio n a l re q u ire m e n ts o f the d e n titio n .10,11 Also, orthodontists could use com posite restorative m aterials more
often in the retention phases o f or thodontic treatment.
O r th o d 7 2 ( l) :8 5 - 9 2 ,1 9 7 7 . 3 . B a e r , P .N ., a n d M o r r is , J .L . T e x t b o o k o f
Summary
p e r io d o n tic s . P h ila d e lp h ia , J. B . L ip p in c o t t C o ., 1 9 7 7 ,p 18 5 .
In dental practice, combined plans of o r th o d o n tic a nd p ro s th o d o n tic treatment are underused. Indications fo r a co lla bo ra tive e ffo rt in c lu d e preservation of integ rity o f the dental arch, biomechanical factors, lim ita tions in design o f prostheses, esthetic appearance, p e rio d o n ta l c o n s id erations, p re ven tion o f m a lo cclu sion, and better retention of position of teeth.
4 . S c h lu g e r , S .; Y o u d e lis , R .A .; a n d
Page,
R . C . P e r i o d o n t a l d is e a s e s . P h i l a d e l p h i a , L e a & F e b ig e r , 1 9 7 7 , p 6 1 2 . 5 . H o o d , J . A . A . ; F a r a h , J .W .; a n d C r a ig , R .G . M o d ific a tio n
o f s tre s s e s in
a lv e o la r b o n e in
d uced
t ilte d
J P ro s th e t D e n t
b y
a
m o la r .
3 4 (4 ):4 1 5 -4 2 1 , 1 9 7 5 . 6 . In g b e r , J .S . F o r c e d e r u p t io n . A m e t h o d o f t r e a t in g
n o n r e s to r a b le te e th — p e r io d o n t a l a n d
r e s to r a tiv e
c o n s id e r a t io n s .
J P e r io d o n to l
4 7 (4 ):2 0 3 -2 1 6 , 1 9 7 6 . 7 . B r o w n , I.S . T h e e ffe c t o f o r th o d o n tic th e r a p y o n c e r t a in ty p e s o f p e r io d o n ta l d e fe c ts . J P e r io d o n to l 4 4 { 1 2 ) :7 4 2 - 7 5 6 ,1 9 7 3 . 8 . K a p la n ,
R .G .
S u p r a c r e s ta l fib e r o to m y .
J A D A 9 5 (5 ):1 1 2 7 -1 1 3 2 ,1 9 7 7 . D r . E v a n s is a s s is ta n t p r o fe s s o r , d e p a r tm e n t o f o r th o d o n tic s , H a r v a r d
S c h o o l o f D e n ta l
9 . Is a a c s o n , R .J ., a n d o th e r s . R e s e a r c h o n v a r ia t io n i n d e n ta l o c c lu s io n . A
“ s ta te -o f-th e -a rt”
M e d ic in e . D r . N a t h a n s o n is a s s o c ia t e p r o f e s s o r ,
w o rk s h o p
d e p a r tm e n t o f r e s to r a tiv e d e n t is t r y , a n d is h e a d ,
A n o m a lie s P r o g r a m , N a tio n a l In s t it u t e o f D e n
d iv is io n o f o p e r a tiv e d e n t is t r y , S c h o o l o f D e n ta l
ta l R e s e a rc h . A m J O rth o d 6 8 (3 ):2 4 1 -2 5 5 ,1 9 7 5 .
M e d ic in e , T u f t s U n iv e r s it y . A d d r e s s r e q u e s ts
c o n d u c te d
1 0 . S c h lu g e r , S . T h e
f o r r e p r in t s t o D r . E v a n s , A s s is ta n t P r o fe s s o r o f
p o s to r th o d o n tic
O r th o d o n t ic s , H a r v a r d
5 2 5 -5 2 7 , 1 9 6 8 .
S c h o o l o f D e n ta l
M e d ic in e , 1 8 8 L o n g w o o d A v e , B o s to n , 0 2 1 1 5 . 1.
B a r r e r , H .G . T h e a d u lt o r t h o d o n t ic p a tie n t.
b y
th e
C r a n io fa c ia l
p e r io d o n tis t a n d
p a tie n t. D e n t C lin
N
th e
A m e r
1 1 . W illia m s , R . L . O c c lu s a l t r e a t m e n t f o r th e p o s to r th o d o n tic
A m J O rth o d 7 2 (7 ):6 1 7 -6 4 0 ,1 9 7 7 .
8 3 0 ■ J A D A , V o l. 9 9 , N o v e m b e r 1 9 7 9
2 . T u r p in , D .L . L o n g R a n g e S tu d y C o m m it te e r e le a s e s r e s u lt s o f m a n p o w e r s u r v e y . A m J
5 9 (5 ):4 3 1 -4 4 2 , 1 9 7 2 .
p a tie n t.
A m
J O rth o d
