Rheumatoid arthritis and disk derangement of the temporomandibular joint. A comparative arthroscopic study.

Consecutive patients with clinical diagnoses of disk derangement and rheumatoid arthritis with temporomandibular joint (TMJ) signs and symptoms were compared by clinical, radiographic, and arthroscopic examination. Synovial biopsies were obtained from patients with arthroscopic features of synovial inflammation. No clinical sign or symptom was found to be specific of rheumatoid involvement although joint crepitation was most frequently found in rheumatic patients (p less than 0.001). Tomographic features of subchondral bone involvement were more frequently revealed in TMJs of rheumatic patients (p less than 0.001). At arthroscopy rheumatic patients often showed pronounced arthrotic changes and inflammation. In contrast to patients with disk derangement, fibrosis of the TMJ was frequent (p less than 0.001). Histologic examination of obtained synovial specimens correlated well with arthroscopic findings, and more pronounced inflammation was present in specimens from rheumatic patients.