MRI of the Temporomandibular Joint in Patients with Rheumatic Disease

Objectives: To evaluate MRI findings of the temporomandibular joint (TMJ) in patients with rheumatic disease.

Methods: Sixty-two rheumatic patients (124 TMJs) with clinical signs such as TMJ pain or discomfort who were examined by MRI at our hospital between May 1996 and January 2008 were included in this study. In all?patients, rheumatic disease was confirmed by the American Rheumatism Association classification criteria. Sixty-four nonrheumatic patients (108 TMJs) with clinically suspected internal derangement of the TMJ who were examined by MRI in June and July 2007, were also included as a control group. Two oral radiologists independently evaluated MR images of the rheumatic and nonrheumatic patient groups to determine the presence or absence of disk displacement, joint effusion and osseous changes, and visualization of temporal posterior attachment (TPA). By comparing MR findings between the two groups, we attempted to define characteristic MR findings of the TMJ in patients with rheumatic disease. Statistical analysis was performed using chi-square test.

Results: As for the prevalence of disk displacement and joint effusion, there was no significant difference between rheumatic and nonrheumatic patients. TPA was visualized in 29%(36/124TMJs) in rheumatic patients and in 48%(52/108) in nonrheumatic patients, and the visualization was significantly inferior in the former than the latter (P< 0.01). Osseous abnormalities of the condyle were more common in rheumatic patients (75%; 93/124) than nonrheumatic patients (56%; 60/108) (P< 0.01). The most common osseous change in rheumatic patients was erosion, which was observed in nearly half of the TMJs in that group (59/124). Twenty percent (25/124) of the condyles of rheumatic patients showed severe bone destruction, which was a specific feature in this patient group.

Conclusion: Characteristic MRI findings of the TMJs in rheumatic patients were the obscurity of TPA visualization and the presence of osseous changes in the condyle.