Original Article. Department of Orthodontics, Göteborg University, Göteborg, Sweden. b

Transcription

1 Originl Article A -Yer Follow-up of Signs nd Symptoms of Temporomndiulr Disorders nd Mlocclusions in Sujects With nd Without Orthodontic Tretment in Childhood Inger Egermrk, LDS, Odont Dr/PhD ; Toms Mgnusson, LDS, Odont Dr/PhD ; Gunnr E. Crlsson, LDS, Odont Dr/PhD, Dr Odont hc, FDSRCS c Astrct: This investigtion nlyzes the influence of orthodontic tretment on signs nd symptoms of temporomndiulr disorders (TMDs) nd different mlocclusions during -yer period. Originlly, rndomly selected 7-, -, nd 5-yer-old sujects were exmined cliniclly nd y mens of questionnire for signs nd symptoms of TMDs. The exmintion ws repeted fter five nd ten yers. After yers, sujects (5% of the trced sujects) completed the questionnire. The oldest ge group, now 5 yers of ge, ws invited to clinicl exmintion, nd sujects (% of the trced sujects) were exmined. The correltions etween signs nd symptoms of TMD nd different mlocclusions were minly wek, lthough sometimes sttisticlly significnt. Lterl forced ite nd unilterl crossite were correlted with TMD signs nd symptoms t the - nd -yer follow-ups (r., P.5 nd r., P., respectively). Sujects with mlocclusion over long period of time tended to report more symptoms of TMD nd to show higher dysfunction index, compred with sujects with no mlocclusion t ll. There were no sttisticlly significnt differences in the prevlence of TMD signs nd symptoms etween sujects with or without previous experience of orthodontic tretment. This -yer follow-up supports the opinion tht no single occlusl fctor is of mjor importnce for the development of TMD, ut lterl forced ite etween retruded contct position (RCP) nd intercuspl position (ICP), s well s unilterl crossite, my e potentil risk fctor in this respect. Furthermore, sujects with history of orthodontic tretment do not run higher risk of developing TMD lter in life, compred with sujects with no such experience. (Angle Orthod ;7: 5.) Key Words: Temporomndiulr disorders, Mlocclusion, Orthodontic tretment INTRODUCTION Epidemiologicl studies hve shown tht sujective symptoms nd clinicl signs of temporomndiulr disorders (TMD) re commonly found oth in children nd dults. It is generlly greed tht such signs nd symptoms re mostly mild in childhood nd tht they increse slightly with ge up to dolescence, oth in prevlence nd severity. 7 Studies on the consequences of orthodontic tretment on TMD hve shown tht such tretment neither increses nor decreses the risk of developing TMD lter in life. 5,, But the Deprtment of Orthodontics, Göteorg University, Göteorg, Sweden. The Institute for Postgrdute Dentl Eduction, Jönköping, Sweden. c Deprtment of Prosthetic Dentistry/Dentl Mterils Science, Göteorg University, Göteorg, Sweden. Corresponding uthor: Dr. Inger Egermrk, Deprtment of Orthodontics, Box 5, SE 5 Göteorg, Sweden. Accepted: August. Sumitted: June. y The EH Angle Eduction nd Reserch Foundtion, Inc. results re not conclusive, nd some recent studies hve found less prevlent TMD signs nd symptoms in sujects who hve received orthodontic tretment, compred with orthodonticlly untreted sujects. During the lst decdes, severl investigtions hve focused on morphologicl nd functionl mlocclusions s well s signs nd symptoms of TMD.,5,,5, In other studies, efforts hve een mde to evlute the possile etiologicl importnce of occlusl fctors for the development of TMD.,7 These studies indicte, in generl, tht occlusl fctors re of minor etiologicl importnce for pin nd functionl disorders in the mstictory system. But the role of occlusion in the etiology of TMD is still controversil., The ojective of the present study ws to evlute whether previously received orthodontic tretment, s well s different morphologicl nd functionl mlocclusions, hd ny consequences for the long-term development of signs nd symptoms of TMD in children nd dolescents who hve een followed longitudinlly for period of yers. Angle Orthodontist, Vol 7,,

2 EGERMARK, MAGNUSSON, CARLSSON MATERIALS AND METHODS Becuse detiled description of the sujects included nd the methods used hs een presented recently, 5, only rief summry is given here. Sujects Originlly, rndomly selected 7-, -, nd 5-yerold sujects were exmined y mens of questionnire on TMD symptoms, hedches, nd orl prfunctions nd cliniclly regrding signs of TMD nd occlusl fctors. The results were pulished in doctorl thesis. The investigtion ws repeted fter 5 nd yers, using the sme methods, nd the results hve een pulished erlier. 7,,,7,,7, Twenty yers fter the first exmintion, n ttempt ws mde to find the ddresses of the originl prticipnts, who t tht time hd reched the ges of 7,, nd 5 yers, respectively. Three hundred seventy-eight individuls of the originl group could e trced (%). The trced sujects were ll sent questionnire, nd (% of the originl smple, 5% of the trced sujects), 7 women nd 5 men, completed nd returned the questionnire. Sujects elonging to the oldest ge group, originlly 5 rndomly selected 5-yer-old individuls, now 5 yers of ge, were lso invited to clinicl exmintion. Of the individuls who could e trced, completed nd returned the questionnire, nd ( women nd 5 men) were lso sujected to functionl exmintion of the mstictory system (% nd % of the trced sujects, respectively). Methods The questionnire focused on the presence of symptoms from the mstictory system such s temporomndiulr joint (TMJ) clicking, difficulties in mouth opening, pin nd tiredness in jws, s well s hedches nd orl prfunctions. At the -yer follow-up, the sujects were lso sked out previous orthodontic tretment (fixed pplinces or more simple orthodontic tretment such s removle pltes, hedger, etc). At the -yer follow-up, informtion out previous orthodontic tretment performed in the oldest ge group ws otined y scrutinizing the individul cse records. The stndrdized clinicl exmintion, comprised mesurements of the rnge of movement of the mndile, presence of deflection during mouth opening, registrtion of TMJ sounds, joint locking or luxtion, pin on movement of the mndile, nd TMJ or muscle pin on plption. From these clinicl prmeters, clinicl dysfunction index ccording to Helkimo ws clculted. The registrtion of morphologicl mlocclusions, such s post- nd prenorml occlusion, inverted incisors, cross- nd scissors ite, deep ite, nterior or lterl open ite, ws mde ccording to the definitions given y Björketl The following findings were registered s functionl mlocclusions (occlusl interferences): unilterl contcts in retruded conttct postition; RCP (grde I/mild: reported y the ptient, grde II/grve: visile to the nked eye), lterl forced ite (.5 mm) etween RCP nd intercuspl position; ICP, nterior forced ite (.5 mm) etween RCP nd ICP, nd occlusl interferences on the nonworking side preventing contct on the working side during lterl excursion. All three uthors took prt in the clinicl exmintions fter clirtion, which hs een descried erlier. The clirtion ws repeted t ech follow-up. The 5-yer-old sujects were lso divided into two sugroups: () no mlocclusion long-term-group contining sujects for whom no morphologicl or functionl mlocclusions hd een registered t the ges of 5 nd 5 yers (n ); nd () mlocclusion long-term-group contining sujects who hd t lest two different mlocclusions, morphologicl nd/or functionl, t the ges of 5 nd 5 yers (n ). Sttisticl methods The Wilcoxon mtched pirs signed rnk test nd Fisher test were used for nlysis of differences etween vriles. The correltion etween vriles ws clculted y mens of the Spermn (r s ) rnk correltion test. The following levels of significnce hve een used: P.5 not significnt,. P.5,. P., P.. RESULTS Previous orthodontic tretment At the -yer follow-up, totl of individuls (%) gve n ffirmtive nswer tht they hd received some kind of orthodontic tretment in childhood. Of the respondents, sujects (%) stted tht they hd not received orthodontic tretment, ut s mny s sujects (%) did not rememer whether they hd received such tretment. The corresponding figures for the oldest group ws %, %, nd %, respectively. In this group, scrutiny of the cse records showed tht 5% hd received orthodontic tretment from specilists, nd % hd received tretment from generl prctitioners. Thus, the differences etween reported nd true vlues were smll. Nevertheless, two orthodonticlly treted sujects did not rememer tht they hd received such tretment, nd three other sujects, not orthodonticlly treted ccording to the cse records, reported such tretment. The prevlence figures of TMJ clicking, other sujective symptoms of TMD, hedche, nd sujective reports of ruxism t the -yer follow-up in respect of whether the sujects hd received previous orthodontic tretment re presented in Tle. There were no sttis- Angle Orthodontist, Vol 7,,

3 TMD AND ORTHODONTIC TREATMENT TABLE. Percentge Distriution of Reported TMJ Clicking, Other Sujective Symptoms of TMD, Hedche, nd Bruxism in 7-, -, nd 5-Yer-Old Sujects (N ) According to Reports of Orthodontic Tretment Vrile Reported TMJ clicking Other sujective symptoms of TMD Hedche Bruxism Orthodontic Tretment (n ) TMJ indictes temporomndiulr joint. TMD indictes temporomndiulr disorder. Orthodontic Tretment (n ) 7 Don t Know (n ) 5 5 ticlly significnt differences etween the groups, ut sujects who hd no experience of orthodontic tretment tended to report more frequent hedche, ruxism, nd sujective symptoms of TMD (TMJ clicking excluded) compred with those who hd received such tretment. According to the cse records, 7 sujects in the oldest ge group hd received orthodontic tretment (mostly fixed pplinces) from specilists in orthodontics. Their ttitude to the orthodontic tretment chnged over time. They were more stisfied with the result of the orthodontic tretment t the ge of 5 yers, compred with yers erlier (Tle ). The 5-yer-old sujects lso nswered some other questions out their orthodontic tretment. At the ge of 5 yers, none of those who hd received orthodontic tretment regretted tht they hd undergone the tretment, nd % should recommend someone in their previous sitution to hve orthodontic tretment performed. Six percent of ll sujects in the oldest ge group expressed present demnd for orthodontic tretment. There ws tendency of less frequent TMD symptoms, hedche, nd ruxism in the corrective group in comprison with the interceptive nd nontretment groups (Tle ). But the differences were not sttisticlly significnt. All the recorded signs nd symptoms of TMD fluctuted considerly during the yers covered y this longitudinl investigtion s reported previously. 5, This ws lso the cse mong those included in the corrective nd interceptive orthodontic groups. Aout hlf of the sujects in ech group did not report TMJ clicking or other sujective symptoms of TMD on ny occsion, wheres one suject in ech group reported one or more such symptoms t ll four exmintions during the -yer period. In ll other cses, there ws sustntil fluctution of symptoms during the exmintion period. TABLE. Distriution of Answers t the - nd -Yer Followups to Questions Aout Orthodontic Tretment Received from Specilists (n 7) Question Did you find the tretment inconvenient? Yes Did you use your removle pplince regulrly? Yes neglected Are you stisfied with the orthodontic tretment result? Yes, very stisfied Yes, cceptle It could e etter, not t ll Hve your teeth relpsed since the tretment? Yes, very much Yes, little After y 7 5 After y TABLE. Percentge Distriution of Reported TMJ Clicking, Other Sujective Symptoms of TMD, Hedche, Bruxism, nd Recorded Clinicl Dysfunction Index in 5-Yer-Old Sujects (N ) Who Hd Erlier Hd Orthodontic Tretment Performed y Specilists (corrective group) nd y Generl Prctitioners (interceptive group) nd Individuls Who Hd t Received ny Orthodontic Tretment Vrile Reported TMJ clicking Other sujective symptoms of TMD Hedche Bruxism Clinicl dysfunction index ne Mild Moderte/severe Corrective (n 7) 5 5 Interceptive (n ) 7 55 Orthodontic Tretment (n ) 5 5 TMJ indictes temporomndiulr joint; TMD, temporomndiulr disorder. N, nd N in the three groups ws,, nd 7, respectively. Angle Orthodontist, Vol 7,,

4 EGERMARK, MAGNUSSON, CARLSSON TABLE. Prevlence in Percent of Different Morphologicl nd Functionl Mlocclusions on Three Occsions in 5 5-Yer-Old Sujects, Some of Whom Were Followed for Yers Type of Mlocclusion 5 y 5 y 5 y c Postnorml occlusion Prenorml occlusion Deep ite (overite 5 mm) Anterior open ite (overite mm) Lterl open ite Crossite Bilterl Unilterl Scissors ite Inversion of incisors Extreme mxillry overjet ( mm) nworking side interferences Lterl forced ite RCP d /ICP e (.5 mm) Anterior forced ite RCP/ICP (.5 mm) Unilterl contct in RCP N 5. N. c N. d RCP retruded contct position. e ICP intercuspl position Mlocclusions Among those exmined cliniclly, no gender differences were found for the different mlocclusions, nd therefore the results re pooled for men nd women (Tle ). The prevlence figures for the different mlocclusions were firly constnt during the -yer period, ut the numer of sujects with crossite incresed sttisticlly significntly during the oservtion period (Tle ). At the ge of 5 yers, of the crossites registered were lterlly forced.5 mm etween RCP nd ICP. The registrtion of functionl mlocclusions fluctuted considerly, eg, registrtions of lterl slide.5 mm etween RCP nd ICP ws registered in 5% of the sujects on some occsion ut only in % ws it registered on ll exmintions. At the ge of 5 yers, not less thn 7% of the sujects reported unilterl contct in RCP, nd in %, this premture contct could e seen y the exminer with the nked eye (grve unilterl RCP interference). Some of the mlocclusions were wekly correlted to ech other. For exmple, nonworking side interferences were positively correlted to lterl forced crossite (r., P.), nd lterl forced ite RCP/ICP ws positively correlted oth to unilterl crossite nd unilterl contct in RCP (r., P. nd r., P., respectively). Sttisticlly significnt correltion coefficients etween signs nd symptoms of TMD (including hedche nd ruxism) nd different mlocclusions were few nd, in generl, wek (Tle 5). But oth t the ge of 5 nd 5 yers, the lterl forced ite etween RCP nd ICP ws sttisticlly significntly correlted to sujective symptoms of TMD (r., P.5 nd r., P.5, respectively). At the ge of 5 yers, TMJ clicking ws three times more common mong those who hd unilterl crossite yers erlier (r.5, P.) nd more thn twice s common mong those with lterl forced ite t present (r., P.). For the other correltions found, no conclusive pttern could e seen (Tle 5). The mlocclusion long-term-group reported more frequent TMD symptoms nd ruxism nd hd more severe clinicl dysfunction thn the no mlocclusion long-termgroup (Tle ). The differences, however, did not rech sttisticlly significnt levels. Among the 5-yer-old sujects, totl of six sujects hd severe clinicl signs of dysfunction nd/or frequent TABLE 5. Significnt (P.5) Spermn Rnk Correltions (r s ) in 5-Yer-Old Sujects Between Reported TMJ Clicking, Other Sujective Symptoms of TMD, Hedche, Bruxism (N ), nd Clinicl Dysfunction Index (N ), Respectively, nd Different Mlocclusions t the First Exmintion nd After nd Yers Vrile t 5 y of Age First Exmintion t Age 5 y After y t Age 5 y After y t Age 5 y TMJ clicking Unilterl crossite** (r.5) Lterl forced ite RCP/ICP** (r.) Hedche Crossite* (r.) Frontl open ite* (r.) Grve unilterl RCP interference* (r.) Postnorml occlusion** (r.) Postnorml occlusion** (r.) Unilterl RCP interference* (r.) Bruxism Unilterl crossite* (r.) Deep ite* (r.) Sujective symptoms of TMD, excluding clicking Lterl forced ite RCP/ICP* (r.) Lterl forced ite RCP/ICP* (r.) Clinicl dysfunction index TMJ indictes temporomndiulr joint; TMD, temporomndiulr disorder. *. P.5, **. P.. Grve unilterl RCP interference** (r.5) Lterl forced ite RCP/ICP** (r.) Angle Orthodontist, Vol 7,,

5 TMD AND ORTHODONTIC TREATMENT TABLE. Prevlence Figures in Percent of Reported TMJ Clicking, Other Sujective Symptoms of TMD, Hedche, Bruxism, nd Recorded Clinicl Dysfunction Index in 5-Yer-Old Sujects Among Those Who Hd t Lest Two Different Mlocclusions Both t the - nd -Yer Follow-ups (n ) nd Among Those Who Hd Mlocclusions Registered (n ) Vrile Reported TMJ clicking Other sujective symptoms of TMD Hedche Bruxism Clinicl dysfunction index ne Mild Moderte/severe Mlocclusion Long-Term- 5 5 Mlocclusion Long-Term- 7 7 TMJ indictes temporomndiulr joint; TMD, temporomndiulr disorder. symptoms of TMD oth t the - nd -yer follow-ups. Two of these sujects hd no mlocclusion, wheres four of them hd lterl forced ite etween RCP nd ICP nd/or unilterl crossite. Seven sujects hd no signs or symptoms of TMD t ny of the two follow-up exmintions. Two of them hd no mlocclusion, wheres five of them hd either postnorml occlusion or deep ite. One of them lso hd nonworking side interferences. DISCUSSION When considering the length of this follow-up investigtion, the loss of prticipnts is extremely smll. Furthermore, the sujects who were lost did not differ from those who prticipted with respect to gender or to ny of the originlly recorded signs or symptoms of TMD ccording to previous nlysis. 5, All the clinicl exmintions followed the sme methods nd were performed y the sme exminers. The questionnires used hve een the sme from the first investigtion to the lst one performed yers lter, with the exception of few dded questions. These circumstnces hve proly minimized the errors, ut, s lwys, results from questionnires, s well s from clinicl exmintions sed minly on semiojective prmeters, should e interpreted with cution. sttisticlly significnt differences could e found etween the orthodonticlly treted nd untreted sujects regrding sujective symptoms of TMD, including hedches, or reports of ruxism, lthough the figures were numericlly higher mong orthodonticlly untreted sujects, compred with those who hd received such tretment. Also in the oldest ge group, for which informtion out previous orthodontic tretment ws gthered from the ptients cse records, only smll differences concerning symptoms of TMD could e found. Thus, in greement with severl previous investigtions, the present findings support the opinion tht sujects who hve received orthodontic tretment do not run higher risk of developing signs or symptoms of TMD lter in life.,,, An lterntive view on this issue is tht the sujects who needed nd received orthodontic tretment s children, hd, s grown-ups, reched the sme level regrding risk for developing TMD signs nd symptoms s those who did not need such tretment. In Sweden, free dentl helth system exists, wherey children receive orthodontic tretment when indicted. One frequent indiction is occlusl disturnces. We cn ssume tht children who hd received orthodontic tretment hd originlly worse occlusl sitution, possily with less fvorle prognosis regrding development of TMD. The present results lso support the opinion tht correltions etween TMD nd different kinds of mlocclusions re nonexistent or wek lso in the long-term perspective of yers. We, however, cnnot totlly neglect the importnce of occlusl fctors in the complex nd controversil concept of TMD etiology ecuse wek, ut still significnt, ssocitions were found etween long-term development of TMD nd some mlocclusions. Especilly, lterl forced ite etween RCP nd ICP, s well s unilterl crossite, should e considered in this context. The possile etiologicl importnce of these occlusl fctors for the development of TMD in the present group hs een stressed previously 7, nd corroortes recently pulished results y others.,5 7 The finding tht four of six sujects with severe clinicl signs nd/or frequent sujective symptoms of TMD t oth the - nd -yer follow-ups hd lterl forced ite etween RCP nd ICP nd/or unilterl crossite supports the findings y Mohlin et l, 5 who found tht crossite ws more common in TMD ptients compred with controls. The increse of nonworking side interferences from 5 to yers of ge is logicl ecuse third molrs often erupt during this period, nd these teeth contriute to most nonworking side interferences. The increse of crossite is proly lso ttriutle to the eruption of the third molrs, resulting in lck of spce in the lterl segments with possile development of crossite. The nswers to questions out previously received orthodontic tretment re interesting. It is ovious tht mjority ws stisfied with the results of the tretment oth in - nd -yer perspective. It is, however, lso ovious tht in the longer perspective, perhps ecuse of fding memory or more mture judgment, the opinion out the tretment result is even more positive. For instnce, minor Angle Orthodontist, Vol 7,,

6 EGERMARK, MAGNUSSON, CARLSSON relpses fter orthodontic tretment re forgotten in longterm perspective. At the -yer follow-up, hlf of the sujects reported no relpse of the orthodontic tretment, figure tht hd incresed to 7% t the -yer follow-up. The reports of lrge relpses were the sme t the - nd -yer follow-ups (%). In spite of this, ll were very stisfied with the result of the orthodontic tretment t the lst follow-up. Mny of the 5-yer-old sujects sid tht they experienced the present period of their lives, with respect to fmily nd work, s much clmer compred with their sitution yers erlier. This my lso hve influenced their judgment out, nd cceptnce of, the tretment result. CONCLUSIONS The present investigtion seems to wrrnt the following conclusions: Sujects who previously hve received orthodontic tretment re in generl very plesed with the tretment result, especilly in long-term perspective. Sujects who hve received orthodontic tretment in childhood do not run n incresed risk of developing signs or symptoms of TMD lter in life. Correltions etween signs nd symptoms of TMD nd different kinds of mlocclusion re in generl nonexistent or wek, ut lterl forced ite etween RCP nd ICP, s well s unilterl crossite, might e of importnce in some individuls. ACKNOWLEDGMENT This investigtion ws supported y grnts from the Reserch Council, County of Hllnd, Sweden nd the Swedish Dentl Society. REFERENCES. Egermrk-Eriksson I. Mndiulr dysfunction in children nd individuls with dul ite [thesis]. Swed Dent J. ;(suppl): 5.. Mohlin B. Need nd Demnd for Orthodontic Tretment with Specil Reference to Mndiulr Dysfunction. A Study in Men nd Women [thesis]. Göteorg, Sweden: Fculty of Odontology, University of Göteorg;.. Nydell A, Helkimo M, Koch G. Crniomndiulr disorders in children. A criticl review of the literture. Swed Dent J. ; : 5.. Crlsson GE, LeResche L. Epidemiology of temporomndiulr disorders. In: Sessle BJ, Brynt PS, Dionne RA, eds. Temporomndiulr Disorders nd Relted Pin Conditions. Progress in Pin Reserch nd Mngement. Settle, Wsh: IASP Press; 5:. 5. Luther F. Orthodontics nd the temporomndiulr joint: where re we now? Prt. Angle Orthod. ;:5.. Luther F. Orthodontics nd the temporomndiulr joint: where re we now? Prt. Angle Orthod. ;:5. 7. Mgnusson T, Egermrk-Eriksson I, Crlsson GE. Five-yer longitudinl study of signs nd symptons of mndiulr dysfunction. J Crniomndi Prct. ;:.. Mgnusson T, Crlsson GE, Egermrk I. Chnges in sujective symptoms of crniomndiulr disorders in children nd dolescents during -yer period. J Orofc Pin. ;7:7.. Wänmn A. Crniomndiulr disorders in dolescents [thesis]. Swed Dent J. 7;(suppl):.. Pilley JR, Mohlin B, Shw WC, Kingdon A. A survey of crniomndiulr disordes in 5 -yer-olds. Eur J Orthod. 7; : McNmr JA, Seligmn D, Okeson JA. Occlusion, orthodontic tretment, nd temporomndiulr disorders: review. J Orofc Pin. 5;:7.. Egermrk I, Thilnder B. Crniomndiulr disorders with specil reference to orthodontic tretment: n evlution from childhood to dulthood. Am J Orthod Dentofcil Orthop. ;:.. Ohlsson M, Lindquist B. Mndiulr function efore nd fter orthodontic tretment. Eur J Orthod. 5;7:5.. Henrikson T. Temporomndiulr disorders nd mndiulr function in reltion to Clss II mlocclusion nd orthodontic tretment. A controlled, prospective nd longitudinl study [thesis]. Swed Dent J. ;(suppl):. 5. Pilley JR, Mohlin B, Shw WC, Kingdon A. A survey of crniomndiulr disorders in 5-yer-olds. A follow-up study of children with mlocclusion. Eur J Orthod. ;:5.. De Boever JA, Crlsson GE, Klineerg IJ. Need for occlusl therpy nd prosthodontic tretment in the mngement of temporomndiulr disorders. Prt I. Occlusl interferences nd occlusl djustment. J Orl Rehil. ;7: Egermrk-Eriksson I, Crlsson GE, Mgnusson T. A long-term epidemiologic study of the reltionship etween occlusl fctors nd mndiulr dysfunction in children nd dolescents. J Dent Res. 7;:7 7.. Kirveskri P, Alnen P, Jämsä T. Assocition etween crniomndiulr disorders nd occlusl interferences. J Prosthet Dent. ;:.. Egermrk-Eriksson I, Crlsson GE, Mgnusson T, Thilnder B. A longitudinl study on mlocclusion in reltion to signs nd symptoms of crniomndiulr disorders in children nd dolescents. Eur J Orthod. ;: 7.. Heikinheimo K, Slmi K, Myllärniemi S, Kirveskri P. A longitudinl study of occlusl interferences nd signs of crniomndiulr disorder t the ge of nd 5 yers. Eur J Orthod. ;: 7.. Crlsson GE, De Boever JA. Epidemiology. In: Zr GA, Crlsson GE, Sessle BJ, Mohl ND, eds. Temporomndiulr Joint nd Mstictory Muscle Disorders. Copenhgen: Munksgrd; : Pullinger AG, Seligmn DA. Quntifiction nd vlidtion of predictive vlues of occlusl vriles in temporomndiulr disorders using multifctoril nlysis. J Prosthet Dent. ;: 75.. Kirverskri P, Jms T, Alnen P. Occlusl djustment nd the incidence of demnd for temporomndiulr disorder tretment. J Prosthet Dent. ;7:.. Greene CS. The etiology of temporomndiulr disorders: implictions for tretment. J Orofc Pin. ;5: Mgnusson T, Egermrk I, Crlsson GE. A longitudinl epidemiologic study of signs nd symptoms of temporomndiulr disorders from 5 to 5 yers of ge. J Orofc Pin. ;:.. Egermrk I, Crlsson GE, Mgnusson T. A -yer longitudinl study of sujective symptoms of temporomndiulr disorders from childhood to dulthood. Act Odontol Scnd. ;5:. 7. Mgnusson T, Egermrk-Eriksson I, Crlsson GE. Four-yer longitudinl study of mndiulr dysfunction in children. Community Dent Orl Epidemiol. 5;:7. Angle Orthodontist, Vol 7,,

7 TMD AND ORTHODONTIC TREATMENT. Mgnusson T, Crlsson GE, Egermrk I. Chnges in clinicl signs of crniomndiulr disorders from the ge of 5 to 5 yers. J Orofc Pin. ;:7 5.. Crlsson GE, Mgnusson T. Mngement of Temporomndiulr Disorders in the Generl Prctice. Chicgo: Quintessence; : 77.. Helkimo M. Studies on Function nd Dysfunction of the Mstictory System [disserttion]. Göteorg, Sweden: University of Göteorg; 7.. Björk A, Kres AA, Solow B. A method for epidemiologicl registrtion of mlocclusion. Act Odontol Scnd. ;:7.. Crlsson GE, Egermrk-Eriksson I, Mgnusson T. Intr- nd interoserver vrition in functionl exmintion of the mstictory system. Swed Dent J. ;:7.. Siegel S. nprmetric Sttistics. New York, NY: McGrw-Hill; 5:75 ;. 5. Lgerström L, Egermrk I, Crlsson GE. Signs nd symptoms of temporomndiulr disorders in -yer-old individuls who hve undergone orthodontic tretment. Swed Dent J. ;: Mohlin B, Derweduwen K, Pilley R, Kingdom A, Shw WC, Kenely P. Mlocclusion nd TMD. A comprison of sujects with moderte to severe dysfunction with those without signs nd symptoms of TMD followed from to yers of ge. J Orthod. In press.. Olson M, Lindqvist B. Occlusl interferences in orthodontic ptients efore nd fter tretment nd in sujects with minor orthodontic tretment need. Eur J Orthod. In press. 7. Thilnder B, Guillermo R, Pen L, De Myorg C. Prevlence of temporomndiulr dysfunction nd its ssocition with mlocclusion in children nd dolescents: n epidemiologic study relted to specified stges of dentl development. Angle Orthod. ;7: 5. Angle Orthodontist, Vol 7,,