The Study on the Change of theTemporomandibular Joint (TMJ) DiscPosition After Orthognathic SurgeryBum-Soo Kim, DDS, Department of Dentistry, SeoulNational University Bundang Hospital, Gumi-Dong,Bundang-Gu, Seongnam-Si, Kyungkee-Do, 463-707,Korea (Kim JW; Yun PY; Kim YK)

Statement: The short and long term influences of or-thognathic surgery on temporomandibular joint (TMJ)functions are unclear.

The aim of this study was to show the influence of orthog-nathic surgery on the TMJ postoperatively by evaluating thedifferences between the position of the TMJ disc on magneticresonance imaging (MRI) before and after surgery.

Materials and Methods: The changes in the TMJ were in-vestigated after a bilateral sagittal split ramus osteotomy(BSSRO) for orthognathic surgery. Both condyles from 24subjects (10 male, 14 female and 18-33 years old) were in-cluded in this study, and MRI imaging was performed beforeand after orthognathic surgery from June 2004 to December2006. The differences between the pre- and post- surgery inthe TMJ disc position were estimated based on the MRI im-ages and were analyzed statistically with correlation analysis.

Method of Data Analysis: n/aResults: The preoperative TMJ symptoms disappeared

in one out of seven subjects, who had anterior discdisplacement before surgery and 3 subjects showed im-provement in their disc position. However, 1 subjectshowed anterior disc displacement without a reductionon the other side and 3 subjects showed an increasingtendency in the anterior disc position.

Conclusion: Correlation analysis showed that therewas no significant difference between the preoperativeand postoperative disc displacement. Therefore, achange in disc displacement does appear to affect thefunction of the TMJ clinically.

References

Saka B, Petsch I, Hingst V, Hartel J. The influence of pre- andintaoperative positioning of the condyle in the centre of the articularfossa on the position of the disc in orthognathic surgery. A magneticresonance study. Br J Oral Maxillofac Surg 2004;42:120-6

Yamada K, Hanada K, Hayashi T. Condylar bony change, disk dis-placement, and signs and symptoms of TMJ disorders in orthognathicsurgery patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod2001;91:603-10

Temporomandibular Joint ArthroscopicArthroplasty with Rigid Disc Fixation—Preliminary Results in Treatment ofWilkes Internal Joint Derangement StagesII-V: A 3-Year Retrospective StudyRamon Perez, DMD, 3200 S. University Dr, Dept. ofOMFS, Davie, FL, 33328 (Kim K; Mossak H; KaltmanSI; McCain JP)

Statement: A great deal of literature exists on themanagement of patients with internal derangement ofthe temporomandibular joint (TMJ). Ohnishi in 1975described a technique of TMJ arthroscopy and ever sincethen, numerous reports have been published advocatingthe high degree of success with arthroscopic lysis andlavage. The largest of these studies, a 6-year multicenterretrospective analysis of 4,831 joints reveals just over a91% favorable outcome for pain and range of motionafter variations of arthroscopic surgery. As operativearthroscopy has evolved, so have the surgical tech-niques. McCarty and Farrar in 1979 described an openprocedure for disc repositioning (discopexy). Althougharthroscopic disc repositioning using semi-rigid fixationwith sutures has been reported, there is no account inthe literature of using rigid fixation. Previous successfultreatments with open rigid fixation provide another op-erative option that may become standard of care as moreathroscopic surgeons become familiar with it. This in-vestigation aims to evaluate the efficacy of arthroscopicdiscopexy with rigid fixation (ADRF) for different stagesof internal joint derangement.

Materials and Methods: A retrospective chart reviewwas performed in 66 patients involving 98 joints treatedfor TMJ internal derangement from 2003-2005. Of these,32 patients underwent bilateral ADRF. 5 males and 61females aged 14-65 with a mean age of 37 years weretreated with ADRF. Inclusion criteria for the study wereall patients treated with ADRF during the three yearspan. All patients had documented follow-up evaluationsfor maximum incisal opening (MIO), change in diet, andpain medication usage at 1 week, 2 weeks, 6 weeks, and6 months post-operatively. Further inclusion criteria in-cluded those patients who underwent standard conser-vative treatment consisting of soft diet, occlusal splinttherapy, and anti-inflammatory medication prior to sur-gery. These patients were then evaluated for pain, click-ing, and range of motion. No exclusion criteria existedfor this study.

Method of Data Analysis: All patients’ symptoms wereevaluated to assess need for surgery. Pain was evident in92% of patients, 91% presented with clicking, and 79%presented with a decreased range of motion. 54% pre-sented with all three symptoms. Patients were also eval-uated for severity of internal derangement according tothe Wilkes’ classification stages II-V. Surgical outcomeswere evaluated according to changes in maximum in-cisal opening (MIO), diet, and pain medication usage 6months after surgery. MIO was evaluated quantitatively 1week before and 6 months after surgery with a millime-ter ruler. Diet assessment and pain medication usagewere evaluated 1 week before and 6 months after sur-gery with a questionnaire filled out by each patient. Alldata collected were transferred to a spreadsheet.

Results: 32 of 66 patients underwent bilateral ADRF(43%). 106 (100%) of the TMJ discs were fixated to their

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respective condyles with Linvatec bicortical smart nailsin conjuction with arthroplasty. With regard to Wilkes’classification, 23 (22%) of the total number of jointswere classified as Stage II. 33 (31%) were Stage III. 45(42%) were Stage IV. 5 (5%) were Stage V. The averageMIO for all patients was: Pre-operative (29.9 mm), Post-operative (38.2 mm), and pre- and post-operative change(�12.3 mm). All patients resulted in increased MIO post-operatively. The greatest change in MIO occurred in aStage IV patient who had ADRF and a resulting 25 mmincrease. For Stage II patients who underwent ADRF,MIO increased an average of 9.5 mm, and average post-operative MIO was 37.7 mm. In addition, 7/8 patients(88%) had improved diets and 8/11 patients (73%)stopped taking pain medication 12 weeks post-opera-tively. Stage III patients had an average increase in MIOof 12.3 mm, and an average post-operative MIO of 38.3mm. Improved diets occurred in 11/13 patients (85%),and 10/16 patients (63%) ceased pain medication. StageIV patients averaged an increased MIO of 13.3 mm andaverage post-operative MIO of 38.1 mm. 11/14 patients(79%) had improved diets, and 12/19 patients (63%) nolonger took pain medication. Stage V patients had anaverage MIO increase of 13 mm. Data for diet and painmedication usage were not available for these patients.17 of the total 106 (6%) patients continued to take painmedication 12 weeks after surgery, and 2 of 98 (1.8%)underwent secondary TMJ surgery after 6 months. Therewere no incidents of permanent facial nerve injury, in-fection, or perforated tympanic membranes in any of the98 joints.

Conclusion: Although arthroscopic procedures to cor-rect TMJ internal derangement have been well describedin the literature, there has been no previous documen-tation of arthroscopically rigidly fixating a repositioneddisc. Although lysis and lavage have been proven to betherapeutic for this challenging group of patients, ADRFprovides another effective method of treating, and insome cases reversing the natural progression of internaljoint derangement. The argument can be made that ifthere is a proven, time-tested procedure in lysis andlavage, then why change it? It may become prudent incertain cases that lysis and lavage fails and the patient orsurgeon do not wish to go into secondary aggressivesurgery, such as partial condylectomy, open discec-tomy, or total joint prostheses. As shown by our or-thopedic counter parts arthroscopic surgery usingrigid fixation is the first line of choice before any opensurgery. The preliminary results from our study thusfar warrant that ADRF has its place in TMJ surgery. Theoverwhelming results of only 1.8% of the patientsundergoing secondary surgery is a good indicator thatwe are going in the right direction with this proce-dure, and with further studies it has the potential ofbecoming the standard of care. Additional data from

this ongoing investigation will lend more credence tothese assertions.

References

White D: Atrhroscopic Lysis and Lavage as the preferred treatmentfor Internal

McCain JP, Sanders B, Koslin MG, et al: Temporomandibular jointarthroscopy: A 6 year multicenter retrospective study of 4831 joints.J Oral Maxillofacial Surgery 50:926 1992

Indresano AT: Surgical Arthroscopy as the Preferred Treatment forthe Internal Deragements of the Temporomandibular Joint. J OralMaxillofacial Surg 59:308-312, 2001

Clinical Application of a High FrequencyElectric Knife With Coblation Technologyfor Temporomandibular JointArthroscopic SurgeryTetsuji Kawakami, PhD, Japan (Inoue CT; Ogawa CJ;Fujita H; Kirita T)

Statement: A high frequency electric knife with Cobla-tion technology has been used in the fields of neurosur-gery and orthopaedic surgery. Coblation, derived fromcooler, controlled ablation, is a patented process em-ploying bipolar radiofrequency technology to achieveprecise and rapid tissue removal with minimal thermaldamage to collateral tissue. This study examined theefficacy and safety of this instrument to arthroscopicsurgery of the temporomandibular joint.

Materials and Methods: We clinically applied a highfrequency electric knife, ArthroCare Multielectrode Sys-tem to arthroscopic surgery of the TMJ. This System wasused in 59 joints of 46 patients, 11 males and 35 femaleswith a mean age of 50 years.

Method of Data Analysis: TMJ pain and mandibularmovement were evaluated. The surgical success wasevaluated according to the criteria of the AAOMS sur-geons-Parameters of Care 95.

Results: The range of mouth opening improved from27 mm before surgery to 43 mm after surgery, the visualanalogue scale score of pain during jaw movementsdecreased from 65 to 4. There was no obstruction of thesurgical field by bleeding during detachment or separa-tion of intraarticular tissues, and the operation time wasshortened. These factors improved the efficiency of sur-gery of the TMJ. More efficient and less invasive arthro-scopic surgery could be performed with this system thanwith methods used previously. Our experience indicatesthat the Coblation technology achieves good operativeresults. Patients report significantly less pain followingCoblation surgery compared with earlier surgical ap-proaches, and findings from our series indicate that re-covery and rehabilitation are considerably accelerated.

Conclusion: This system, which improves the safetyand efficiency of surgery, is expected to be applicablealso to arthroscopic surgery of the TMJ.

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