Hypocycloidal multisection tomography and lower-space arthrotomography with videofluoroscopy were performed on 20 symptomatic temporomandibular joints (TMJs) of 17 patients. All patients (16 women, one man, aged 17 to 38 years) had definite or suspected rheumatoid arthritis (adult or juvenile type), ankylosing spondylitis, or psoriatic arthropathy. Bone abnormalities were found in 14 TMJs, primarily cortical erosion (11 joints), but also condylar flattening (three joints). Irregularity in outline of the contrast material, bone contour-contrast material gaps, evidence of adherent discs and/or small joint compartments indicated synovial hyperplasia/pannus formation in 15 joints. Six of these (four with normal disc position) showed perforation between the joint compartments. In those with normal disc position the perforation seemed to occur in the central portion. Ten of the 15 joints had normal disc position; the remaining five had anterior disc displacement without reduction. One joint showed only disc displacement. Most joints with bone abnormalities (12 of 14) showed arthrographic signs of rheumatic involvement. Such signs were also observed in two of the six joints with no bone abnormalities, indicating the value of arthrography in the early diagnosis of patients with rheumatic disease and TMJ problems.