Originl Article TMD in Consecutive s Referred for Orthognthic Surgery Cecili Abrhmsson ; EwCrin Ekberg b ; Thor Henrikson c ; Mri Nilner d ; Bo Sunzel e ; Lrs Bondemrk f ABSTRACT Objective: To nswer the question whether temporomndibulr disorders (TMD) were more common in group of individuls referred for orthognthic surgery thn in control group. The null hypothesis ws tht neither the frequency of signs nd symptoms of TMD or dignosed TMD would differ between the ptient group nd control group. Mterils nd Methods: A smple of 121 consecutive ptients referred for orthognthic surgery t the Deprtment of Orl Mxillofcil Surgery, Mlmö University Hospitl, Sweden, ws interviewed nd exmined regrding signs nd symptoms of TMD nd hedches. A control group ws formed by 56 ge- nd gender-mtched individuls ttending the Deprtment of Orl Dignosis, Fculty of Odontology, Mlmö University, Sweden, nd ublic Dentl Helth Clinic in Oxie, County of Skne, Sweden. TMD dignoses were used ccording to Reserch Dignostic Criteri for Temporomndibulr Disorders (RDC/TMD). Results: The ptient group showed more myofscil pin without limited opening, disc displcement with reduction, nd rthrlgi ccording to RDC/TMD thn the control group. The ptient group lso hd more symptoms nd signs of TMD in generl. Conclusions: The null hypothesis ws rejected becuse ptients who were to be treted with orthognthic surgery hd more signs nd symptoms of TMD nd higher frequency of dignosed TMD compred with the mtched control group. (Angle Orthod. 2009;79:621 627.) KEY WORDS: Temporomndibulr disorders; Orthognthic surgery; led study; Mlocclusion INTRODUCTION An incresed prevlence of temporomndibulr disorders (TMD) from dolescence to dulthood hs been reported in longitudinl studies, which lso hve Reserch Fellow, Deprtment of Orthodontics, Fculty of Odontology, Mlmö University, Mlmo, Sweden. b Associte rofessor, Deprtment of Stomtognthic hysiology, Fculty of Odontology, Mlmö University, Mlmo, Sweden. c Odont Dr, Deprtment of Orthodontics, Fculty of Odontology, Mlmö University, Sweden. d Chir nd rofessor, Deprtment of Stomtognthic hysiology, Fculty of Odontology, Mlmö University, Mlmo, Sweden e Odont Dr, Deprtment of Orl nd Mxillofcil Surgery, Mlmö University Hospitl, Mlmo, Sweden. f Chir nd rofessor, Deprtment of Orthodontics, Fculty of Odontology, Mlmö University, Mlmo, Sweden. Corresponding uthor: Dr Cecili Abrhmsson, Deprtment of Orthodontics, Fculty of Odontology, Mlmö University, Crl Gustfs väg 34, SE-205 06 Mlmö, Sweden (e-mil: cecili.brhmsson@od.mh.se) Accepted: September 2008. Submitted: June 2008. 2009 by The EH Angle Eduction nd Reserch Foundtion, Inc. shown fluctution of signs nd symptoms of TMD over time, with both improvement nd impirment on n individul bsis. 1 3 The most common subtypes of TMD re myofscil pin, disc displcements with reduction, nd rthrlgi. 4 6 Fctors tht hve shown ssocitions with TMD re indirect or direct trum to the mstictory system, ntomic, pthophysiologic, nd psychosocil fctors. 7 9 The importnce of the occlusion nd its role in cusing the onset or perpetution of TMD, compred with other fctors, hs been studied nd is still debted. 8,10 12 Subjects with mlocclusions hve been suggested to hve significntly higher prevlence of signs nd symptoms of TMD thn others. These mlocclusions include Angle Clss II, nterior open bite, deep bite, posterior crossbite, nd extreme mxillry overjet. 10,12 16 In ddition, severe mndibulr retrognthism nd hyperdivergent skeletl pttern hve been suggested to be risk fctors for TMD. 14,17,18 In recent systemtic review 19 considering ltertions of TMD before nd fter orthognthic surgery, heterogeneous study design nd unmbiguous results of the selected studies were found. Thus, no cler picture exists whether individuls re- DOI: 10.2319/060408-293.1 621
622 ABRAHAMSSON, EKBERG, HENRIKSON, NILNER, SUNZEL, BONDEMARK ferred for orthognthic surgery or with dentofcil deformities hve higher prevlence of TMD thn norml individuls. The im of this study ws to investigte whether TMD ws more common in group of individuls referred for orthognthic surgery thn in control group. The null hypothesis ws tht neither frequency of signs nd symptoms of TMD or dignosed TMD ccording to Reserch Dignostic Criteri for Temporomndibulr Disorders (RDC/TMD) would differ between the ptient nd control group. MATERIALS AND METHODS Subjects A smple of 121 consecutive ptients, men ge 22.5 7.4 yers, 70 femles nd 51 mles, with dentofcil deformities ws included. All ptients were referred to the Deprtment of Orl Mxillofcil Surgery, Mlmö University Hospitl, Mlmo, Sweden, between 1992 nd 2002 for orthodontic tretment in combintion with orthognthic surgery. A control group of 56 individuls, men ge 23.4 7.4 yers, 33 femles nd 23 mles, were recruited to mtch the ptients in the tretment group, considering ge nd gender. These individuls were regulr ptients, with or without minor mlocclusion trits tht were not needed to be corrected with either orthodontic therpy or orthognthic surgery, ttending the Deprtment of Orl Dignostics, Fculty of Odontology, Mlmö University, Sweden, nd ublic Dentl Helth Clinic in Oxie, County Skne, Sweden. The exclusion criteri for the 2 groups were crniofcil syndromes, systemic rthritic nd muscle diseses, nd dentition of fewer thn 24 teeth. The study ws pproved by the Ethics Committee of Lund University, Sweden (Ref No LU-241-01). Questionnire nd Clinicl Exmintion All individuls in the ptient group nd control group were ssessed for signs nd symptoms of TMD by mens of questionnire nd clinicl exmintion. In the questionnire, the individuls reported resons for seeking tretment (impired chewing cpcity/symptoms from the mstictory muscles, temporomndibulr joints [TMJs], nd hedches/esthetic resons), the stte of generl helth, use of pinkillers for hedche nd TMD (yes/no), s well s wreness of orl prfunctions s tooth grinding (yes/no), or tooth clenching (yes/no). Frequency of TMD pin, tiredness of the jws, TMJ clicking, nd hedche (never/once or twice month/once week/once or twice week/dily) ws registered s well s pin t rest (yes/no) nd during mndibulr movements (yes/no) nd reported TMJ clicking Tble 1. Clinicl Exmintion nd Registrtion of Temporomndibulr Disorders nd Relted Muscles Mesurement of mndibulr mobility in millimeters Mximum opening cpcity without ssistnce Mximum lterotrusion, left/right Mximum protrusion Mximum retrusion in on movement of the mndible Mndibulr devition 2 mm on opening Temporomndibulr joint (TMJ) clicking nd crepittions registered by plption nd usculttion during opening nd closing of the mndible Tenderness on plption of the TMJs; lterlly nd posteriorly nd mstictory musculture; the origin nd the insertion of the temporl muscles, the superficil nd deep portion of the msseter muscles, nd the insertion of the medil pterygoid muscle (yes/no). The questionnire lso included questions bout the severity of TMD discomfort on visul nlogue scle (VAS) 20 with the endpoints none nd severe nd verbl scle s follows: 0 no or miniml discomfort, 1 slight discomfort, 2 moderte discomfort, 3 severe discomfort, 4 very severe discomfort. Furthermore, the individuls rted themselves on the VAS regrding their level of nxiousness with the endpoints clm nd nervous/nxious. Before the orthognthic tretment ws strted, the clinicl exmintion ws performed t the Deprtment of Stomtognthic hysiology t Mlmö University, by either one of two clibrted 21 specilists. The exmintion included mesurement of mndibulr movements, pin during nonguided mndibulr movements, registrtion of TMJ sounds, nd tenderness of the TMJs nd relted muscles (Tble 1). The relibility of the methods used for clinicl registrtions ws improved by clibrting the exmintion technique between two exminers. Thus, before the study, eight subjects not included in the study were exmined. 21 Furthermore, the specilists conducting the exmintions were not informed of the group to which the individul belonged, nd the extrorl exmintion ws performed before the introrl one. Subdignoses of TMD were used ccording to RDC/ TMD. 4 The dignoses re divided into three groups: 1. Muscle disorders: () myofscil pin, (b) myofscil pin with limited opening 2. Disc displcements: () disc displcement with reduction; (b) disc displcement without reduction, with limited opening; (c) disc displcement without reduction, without limited opening 3. Arthrlgi, rthritis, rthrosis: () rthrlgi, (b) osteorthritis of the TMJ, (c) osteorthrosis of the TMJ The functionl occlusion ws ssessed by methods previously described nd investigted for observer error. 22,23 Nonworking side interferences within lterl
TMD AND ORTHOGNATHIC SURGERY excursion of 3 mm, working side interferences, protrusion interferences, nd the distnce nd the direction of the slide between retruded contct position (RC) nd the intercuspl contct position (IC) were registered. In both groups morphologic occlusion ccording to Björk et l 24 ws registered by introrl exmintion. The ptient group ws further nlyzed by dentl study csts, lterl cephlogrms, nd cephlometric nlysis. 25 A hyperdivergent fcil profile ws clssified s n NSL/ML ngle of 40 nd hypodivergent fcil profile s n NSL/ML ngle of 26. A Clss II skeletl reltionship between the dentl rches ws clssified s n ANB ngle of 6 nd Clss III skeletl reltionship s n ANB ngle of 0. Sttisticl Methods ower for test of the null hypothesis. One gol of the proposed study ws to test the null hypothesis tht the proportion positive ws identicl in the two popultions. The criterion for significnce (lph) ws set t.05. The test ws 2-tiled, which mens tht n effect in either direction ws interpreted. With the proposed smple size of 35 in ech subgroup, the study hd power of 89.8% to yield sttisticlly significnt result. This computtion ssumed tht the difference in proportions ws 0.30 (specificlly, 0.05 vs 0.35) in prevlence of TMD pin. This effect ws selected s the smllest effect tht would be importnt to detect, in the sense tht ny smller effect would not be of clinicl or substntive significnce. Differences between groups nd precision to estimte the effect size. erson s chi-squre test with Yte s correction for continuity ws used when 2 2 cross-tbultions were pplicble. When the expected cell vlue in 2 2 tble ws less thn 5, Fisher s exct test ws used. To compute the difference between rnks nd groups with ordinl dt, the Mnn- Whitney rnk sum test ws used. A second gol of this study ws to estimte the difference between the two groups. Bsed on these sme prmeters nd ssumptions, the study enbled us to report the difference in proportions with precision (95% confidence level) of pproximtely 0.17 points. Specificlly, n observed difference of 0.30 would be reported with 95% confidence intervl of 0.47 to 0.13. When compring mens in numericl vribles, the two-smple t-sttistic ws used. Medin vlue nd percentiles (Q) were clculted when estimting reported nxiety on the VAS. All sttistic procedures were performed with sttisticl softwre SSS 13.0 for Windows (SSS Inc, Chicgo, IL). 623 RESULTS Anmnestic Findings Twenty-one percent in the ptient group nd 2% in the control group used pinkillers for hedche nd/or TMD pin (.001). The self-rted level of nxiousness on the VAS ws similr in the two groups, with medin of 19.5 (Q 1 7, Q 3 47) nd 19.0 (Q 1 6, Q 3 43). There were no differences between the groups concerning reported weekly hedches (.373) or wreness of prfunctionl hbits such s tooth clenching (.665) nd tooth grinding (.080). When the ptients registered their resons for seeking tretment, 75% nswered impired chewing cpcity nd 72% symptoms from mstictory muscles, TMJs, nd hedches. Sixty-six percent reported esthetic resons. Symptoms of TMD The ptient group reported more subjective TMD discomfort on verbl scle (.001) thn did the control group (Figure 1). Also, pin in the TMJs nd/ or mstictory muscles during rest, wide opening, nd chewing were significntly more commonly reported in the ptient group thn in the control group, s well s weekly TMD pin, weekly jw tiredness, nd weekly joint clicking (Tble 2). Clinicl Findings Signs of TMD. There were sttisticlly significnt differences between the ptient group nd the control group with regrd to pin on plption of the TMJs nd relted muscles, devition during opening nd/or closing of the mndible, nd TMJ clicking (Tble 3). However, no differences were found in registered reciprocl clicking or crepittions. During mximum opening, lterotrusion, nd protrusion, the individuls in the control group hd significntly lrger mndibulr movement cpcity thn the ptient group did (Tble 4). Occlusl interferences. A sgittl nd verticl distnce of 1 mm between RC nd IC ws significntly more common in the ptient group thn in the control group. Significntly more individuls in the ptient group hd interferences in lterotrusion, mediotrusion, nd protrusion compred with the control group (Tble 5). TMD dignoses ccording to RDC/TMD. The ptient group hd significntly higher frequency of myofscil pin, disc displcement with reduction, nd rthrlgi compred with the control group (Tble 6). The frequency of myofscil pin with limited opening, osteorthritis, nd osteorthrosis ws low, nd no differences could be found between the two groups.
624 ABRAHAMSSON, EKBERG, HENRIKSON, NILNER, SUNZEL, BONDEMARK Figure 1. Reported temporomndibulr disorder discomfort on verbl scle. Subgrouping into different mlocclusion trits. The distribution of mlocclusion trits is shown in Tble 7. No certin mlocclusion trit could be ssocited with symptoms of TMD or hedche. No differences in the frequency of dignosed RDC/TMD could be seen between different mlocclusion trits. Tble 2. ercentge Distribution of Self-reported TMD Symptoms in the (n 121) nd the (n 56) Symptoms of TMD TMJs/muscles, pin t Rest 18 2.003 Wide opening 34 11.006 Chewing 50 11.000 Rest, wide opening, nd/or chewing 57 16.000 Weekly TMD pin 38 5.000 Weekly jw tiredness 64 9.000 Weekly TMJ clicking 47 8.002 TMD indictes temporomndibulr disorder; TMJ, temporomndibulr joint. DISCUSSION The null hypothesis ws rejected becuse ptients who were to be treted with orthognthic surgery hd more signs nd symptoms of TMD nd higher frequency of dignosed TMD compred with the mtched control group. revious studies ssessing the frequency of TMD in ptients with dentofcil deformities hve been heterogeneous in study design nd hve shown mbiguous results. 13,14,17 19,26,27 However, neither of these studies used RDC/TMD s dignostic tool. It is well known tht signs nd symptoms of TMD re common in helthy popultion nd do not hve to be n indiction of disese. Therefore, the use of the RDC/TMD is importnt since it llows stndrdiztion nd repliction of the most common forms of muscle- nd joint-relted TMD. 4 The RDC/TMD demonstrtes sufficiently high relibility for the most common TMD dignoses, 6 supporting its use in clinicl reserch s well s in decision mking. In the present study, ll individuls were dignosed ccording to RDC/TMD, nd the ptient group hd significntly higher frequency of myofscil pin, disc displcement with reduction, nd rthrlgi thn the control group. Tble 3. ercentge Distribution of Clinicl Signs of TMD in the (n 121) nd the (n 56) Signs of TMD in on plption Muscle pin on plption three sites 31 5.000 TMJ pin on lterl nd/or posterior plption 21 5.009 TMJ sounds Clicking during opening nd/or closing 31 14.021 Reciprocl clicking 19 11.166 Crepittions 4 2.422 Devition on opening/closing of the mndible 2 mm 41 13.000 TMD indictes temporomndibulr disorder; TMJ, temporomndibulr joint.
TMD AND ORTHOGNATHIC SURGERY 625 Tble 4. Mndibulr Movement Cpcity (in mm) in the (n 121) Compred with the (n 56) Mximum Mndibulr Movements Men SD Men SD 95% CI Mximum opening cpcity 49.8 8.0 54.3 6.1 2.1 6.8.000 Mximum lterotrusion, left 8.0 2.6 9.7 2.0 1.0 2.5.000 Mximum lterotrusion, right 8.2 2.6 9.7 2.1 0.8 2.3.000 Mximum protrusion 8.1 3.1 9.9 1.9 0.9 2.7.000 Tble 5. ercentge Distribution of Occlusl Interferences in the (n 121) nd the (n 56) Occlusl Interferences Sgittl distnce between RC nd IC 1.0 mm 41 18.002 Verticl distnce between RC nd IC 1.0 mm 39 16.002 Lterl devition between RC nd IC 0.5 mm 23 20.602 Lterotrusion interferences 27 9.006 Mediotrusion interferences 80 18.000 rotrusion interferences 80 23.000 RC indictes retruded contct position; IC, intercuspl contct position. These TMD dignoses were lso the most prevlent in this mteril, s in the study by John et l. 6 Becuse it is well known tht signs nd symptoms of TMD fluctute over time 3 nd becuse symptom frequencies pper to be ge dependent, 28 it is importnt to include n ge- nd gender-mtched nonptient control group s comprison when evluting the frequency of TMD. In evidence-bsed reserch, usully rndomized controlled tril methodology is recommended. However, in this kind of clinicl tril, it is often not possible for ethicl or prcticl resons to rndomize nd enroll subjects or ptients into tretment or nontretment group. Thus, the control group delibertely consisted of individuls with or without minor mlocclusion trits. No limittions were done considering previous orthodontic tretment. In this study, it ws found tht the ptient group hd more occlusl interferences thn the control group did. In recent review by Luther, 29 it ws concluded tht neither sttic nor dynmic fctors cn be sid to cuse TMD, nd this current study hs not proven otherwise. However, it is interesting to ssess whether occlusl interferences re ltered by orthognthic surgery. Such study hs been commenced nd will be presented lter. The clinicl registrtion of signs of TMD, mndibulr function, nd functionl occlusl interferences ws performed by stndrdized methods, nd the relibility of these methods hs been evluted nd found to be cceptble. 4,30,31 In ddition, it ws decided to perform the orthognthic surgery nd the clinicl TMD exmintions seprtely to ensure the objectiveness of the clinicl TMD exmintion. Furthermore, the relibility of the methods used for clinicl registrtions ws improved by clibrting the exmintion technique between the two exminers. Thus, before the study, eight subjects not included in the study were exmined. In ddition, the specilists were not informed which group their ptients belonged to, nd, moreover, the extrorl exmintion ws crried out before the introrl exmintion in n ttempt of blinding. Two studies 32,33 hve reported tht ptients declred n esthetic motive to be the min reson for seeking orthognthic surgery tretment. This ws not confirmed in this study. Insted, functionl motives were the most frequent, lbeit not significntly higher thn esthetic resons. In fct, mny of the ptients reported more thn one motive for seeking tretment. It cn be pointed out tht mny other fctors, such s socil nd psychologicl concerns, culturl vlues, cost of tret- Tble 6. ercentge Distribution of Reserch Dignostic Criteri for Temporomndibulr Disorders (RDC/TMD) Dignoses in the (n 121) nd (n 56) RDC/TMD Dignosis Tble 7. ercentge Distribution of Dignosed Mlocclusion Trits in the (n 121) Skeletl Dignosis % Mndibulr prognthism 45 Mndibulr retrognthism 7 Open bite in combintion with: Orthognthic jws 17 Mndibulr prognthism 8 Mndibulr retrognthism 16 Deep bite in combintion with: Mndibulr prognthism 4 Mndibulr retrognthism 3 Myofscil pin 30 4.000 Myofscil pin with limited opening 1 0.493 Disc displcement with reduction 19 5.017 Arthrlgi 21 5.007 Osteorthritis 3 0.235 Osteorthrosis 0 2.140 At lest one dignosis (RDC/TMD) 51 18.000 Hving two or more dignoses (RDC/TMD) 19 2.002
626 ABRAHAMSSON, EKBERG, HENRIKSON, NILNER, SUNZEL, BONDEMARK ment, recovery time, nd perceived benefits, re involved nd cn encourge or discourge ptient to pursue surgery. 32 An ttempt ws mde to evlute whether psychologicl stress could be selection bis when compring the frequency of TMD between the groups. However, no differences were found between the two groups when the subjects rted their level of nxiousness on the VAS. Even if the VAS is rw tool to mesure psychologicl distress, it cn still give n indiction of the level of nxiousness in group of individuls. In this study, it ws convincingly demonstrted tht consecutive ptients referred for tretment with orthognthic surgery hd higher frequency of dignoses ccording to RDC/TMD 4 before this tretment compred with n ge- nd gender-mtched control group. However, the question still remins whether orthognthic tretment in these ptients significntly relieves signs nd symptoms of TMD. Such informtion will be presented in further study. CONCLUSION The null hypothesis ws rejected becuse ptients who were to be treted with orthognthic surgery hd more signs nd symptoms of TMD nd higher frequency of dignosed TMD ccording to RDC/ TMD 4 compred with the mtched control group. ACKNOWLEDGMENTS We extend our sincere thnks to Ingrid Crlin nd Birgitt Zhlée, Fculty of Odontology, Mlmö University, nd Ingel Nilsson t Deprtment of Orl nd Mxillofcil Surgery, Mlmö University Hospitl, for clinicl ssistnce during this study. Furthermore, we would like to thnk the ublic Dentl Helth Clinic in Oxie for providing ptients nd tretment rooms. This study ws supported by grnts from the Swedish Dentl Society nd from Fculty of Odontology, Mlmö University, Sweden. REFERENCES 1. Wänmn A, Agerberg G. Two-yer longitudinl study of signs of mndibulr dysfunction in dolescents. Act Odontol Scnd. 1986;44:333 342. 2. Wänmn A, Agerberg G. Two-yer longitudinl study of symptoms of mndibulr dysfunction in dolescents. Act Odontol Scnd. 1986;44:321 331. 3. Mgnusson T, Egermrk I, Crlsson GE. A longitudinl epidemiologic study of signs nd symptoms of temporomndibulr disorders from 15 to 35 yers of ge. J Orofc in. 2000;14:310 319. 4. Dworkin SF, LeResche L. Reserch dignostic criteri for temporomndibulr disorders: review, criteri, exmintions nd specifictions, critique. J Crniomndib Disord. 1992;6: 301 355. 5. List T, Dworkin SF. Compring TMD dignoses nd clinicl findings t Swedish nd US TMD centers using reserch dignostic criteri for temporomndibulr disorders. J Orofc in. 1996;10:240 253. 6. John MT, Dworkin SF, Mncl LA. Relibility of clinicl temporomndibulr disorder dignoses. in. 2005;118:61 69. 7. ullinger AG, Seligmn DA. Trum history in dignostic groups of temporomndibulr disorders. Orl Surg Orl Med Orl thol. 1991;71:529 534. 8. Wänmn A, Agerberg G. Etiology of crniomndibulr disorders: evlution of some occlusl nd psychosocil fctors in 19-yer-olds. J Crniomndib Disord. 1991;5:35 44. 9. Americn Acdemy of Orofcil in. In: Okeson J, ed. Orofcil in Guidelines for Assessment, Clssifiction, nd Mngement the Americn Acdemy of Orofcil in. Chicgo, IL: Quintessence ub; 1996:113 184. 10. Riolo ML, Brndt D, TenHve TR. Associtions between occlusl chrcteristics nd signs nd symptoms of TMJ dysfunction in children nd young dults. Am J Orthod Dentofcil Orthop. 1987;92:467 477. 11. ullinger AG, Seligmn DA, Gornbein JA. A multiple logistic regression nlysis of the risk nd reltive odds of temporomndibulr disorders s function of common occlusl fetures. J Dent Res. 1993;72:968 979. 12. Celic R, Jerolimov V, nduric J. A study of the influence of occlusl fctors nd prfunctionl hbits on the prevlence of signs nd symptoms of TMD. Int J rosthodont. 2002;15:43 48. 13. Miller JR, Burgess JA, Critchlow CW. Assocition between mndibulr retrognthi nd TMJ disorders in dult femles. J ublic Helth Dent. 2004;64:157 163. 14. Miller JR, Mncl L, Critchlow C. Severe retrognthi s risk fctor for recent onset pinful TMJ disorders mong dult femles. J Orthod. 2005;32:249 256. 15. Thilnder B, Rubio G, en L, de Myorg C. revlence of temporomndibulr dysfunction nd its ssocition with mlocclusion in children nd dolescents: n epidemiologic study relted to specified stges of dentl development. Angle Orthod. 2002;72:146 154. 16. hkl RH, Line-Alv MT. Do erly signs of orofcil dysfunctions nd occlusl vribles predict development of TMD in dolescence? J Orl Rehbil. 2002;29:737 743. 17. Nebbe B, Mjor W, rsd NG. Adolescent femle crniofcil morphology ssocited with dvnced bilterl TMJ disc displcement. Eur J Orthod. 1998;20:701 712. 18. Hwng CJ, Sung SJ, Kim SJ. Lterl cephlometric chrcteristics of mlocclusion ptients with temporomndibulr joint disorder symptoms. Am J Orthod Dentofcil Orthop. 2006;129:497 503. 19. Abrhmsson C, Ekberg E, Henrikson T, Bondemrk L. Altertions of temporomndibulr disorders before nd fter orthognthic surgery: systemtic review. Angle Orthod. 2007;77:729 734. 20. Huskisson EC. Mesurement of pin. Lncet. 1974;2:1127 1131. 21. Henrikson T, Ekberg EC, Nilner M. Symptoms nd signs of temporomndibulr disorders in girls with norml occlusion nd clss II mlocclusion. Act Odontol Scnd. 1997;55: 229 235. 22. Vllon D, Ekberg EC, Nilner M, Kopp S. Short-term effect of occlusl djustment on crniomndibulr disorders including hedches. Act Odontol Scnd. 1991;49:89 96. 23. Vllon D, Nilner M, Kopp S. Assessment of occlusl interferences. J Orl Rehbil. 1989;16:279 286. 24. Björk A, Krebs AA, Solow B. A method for epidemiologicl registrtion of mlocclusion. Act Odontol Scnd J. 1964; 22:27 41. 25. Björk A. The Fce in rofile: An Anthropologicl X-ry Investigtion on Swedish Children nd Conscripts [disserttion]. Uppsl, Sweden: University of Lund; 1947.
TMD AND ORTHOGNATHIC SURGERY 26. De Boever AL, Keeling SD, Hilsenbeck S, Vn Sickels JE, Bys RA, Rugh JD. Signs of temporomndibulr disorders in ptients with horizontl mndibulr deficiency. J Orofc in. 1996;10:21 27. 27. Athnsiou AE, Melsen B, Mvres D, Kimmel F. Stomtognthic function of ptients who seek orthognthic surgery to correct dentofcil deformities. Int J Adult Orthod Orthognth Surg. 1989;4(4):239 254. 28. Dibbets JM, vn der Weele LT. Orthodontic tretment in reltion to symptoms ttributed to dysfunction of the temporomndibulr joint. A 10-yer report of the University of Groningen study. Am J Orthod Dentofcil Orthop. 1987; 91:193 199. 29. Luther F. TMD nd occlusion prt II. Dmned if we don t? Functionl occlusl problems: TMD epidemiology in wider context. Br Dent J. 2007;202:E3. 627 30. Crlsson GE, Egermrk-Eriksson I, Mgnusson T. Intrnd inter-observer vrition in functionl exmintion of the mstictory system. Swed Dent J. 1980;4:187 194. 31. Mohlin B, illey JR, Shw WC. A survey of crniomndibulr disorders in 1000 12-yer-olds: study design nd bseline dt in follow-up study. Eur J Orthod. 1991;13:111 123. 32. River SM, Htch J, Dolce C, Bys RA, Vn Sickels JE, Rugh JD. s own resons nd ptient-perceived recommendtions for orthognthic surgery. Am J Orthod Dentofcil Orthop. 2000;118:134 141. 33. Mgnusson T, Ahlborg G, Svrtz K. Function of the mstictory system in 20 ptients with mndibulr hypo- or hyperplsi fter correction by sgittl split osteotomy. Int J Orl Mxillofc Surg. 1990;19:289 293.