Arthroscopic findings in osteoarthritic temporomandibular joints

Purpose: This article reports on the results of a study of the arthroscopic findings in the joint surfaces of osteoarthritic temporomandibular joints (TMJs). Patients and Methods: Arthroscopy was performed in the upper joint compartm ent of 40 TMJs in 40 patients. Thirty-one TMJs that were diagnosed with ost eoarthritis (OA) constituted the Ok group. On the basis of the presence of symptoms related to disc displacement and perforation, OA subgroups were de fined. Nine TMJs that were not involved with OA constituted the control gro up. During the examination, various arthroscopic variables were recorded. D ifferences between groups and between subgroups were tested statistically. Results: In the OA group, several arthroscopic variables were found signifi cantly more frequently than in the control group. These included retrodisca l tissue redundancy, adhesions, and heightened attachment to the posterior wall of the glenoid fossa; articular disc displacement and limited mobility ; and cartilage degeneration in the articular eminence. Moreover, in the OA group, disc displacement was found significantly more frequently in the pe riod after 6 months than during the first 6 months of clinical signs and sy mptoms. Anterodiscal hypervascularity was found significantly more frequent ly during the first year than after the first year, as well as more during the first 2 years than after the first 2 years of clinical signs and sympto ms, whereas a lowered attachment on the anterior slope of the articular emi nence was found significantly more often after 2 years than during the firs t 2 years of clinical signs and symptoms. Conclusions: The findings in this study suggest that OA of the TMJ may init ially result in synovial tissue hypervascularity, creeping synovitis, and r edundancy, and subsequently in adhesion formation and a reduction of the po sterior and anterior recess. Because of cartilage fibrillation on the artic ular eminence, and the subsequently reduced surface smoothness, the articul ar disc may become displaced. Eventually, disc mobility is limited, and adh esions and a reduced posterior and anterior recess prevail.