Ultrasonography of the temporomandibular joint: comparison of findings in patients with rheumatic diseases and temporomandibular disorders. A preliminary report

OBJECTIVE: The objective of the study was to compare findings from ultrasonography (US) of the temporomandibular joint (TMJ) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and temporomandibular disorders (TMD). STUDY DESIGN: US assessment of the temporomandibular joints was bilaterally performed in 68 patients (22 with RA, 11 with PsA, and 35 with TMD). All the TMJs were assessed for the presence of disc displacement, effusion, and changes of the condylar profile, and the prevalence of such abnormalities was compared across the 3 groups of patients. To confirm generalizability of results, US findings were also compared with those of magnetic resonance (MR), taken as the standard of reference. RESULTS: Prevalence of disc displacement and changes in condylar profile were similar between patients with rheumatic diseases and temporomandibular disorders, while effusion was significantly more present in TMJs of TMD patients. Sensitivity of US to detect TMJ abnormalities was acceptable, while specificity was low for condylar alterations. CONCLUSIONS: Temporomandibular joint involvement in patients with rheumatic diseases seems to be similar to that described in subjects with temporomandibular disorders. Ultrasonography confirmed to be an accurate technique to detect disc displacement and effusion within the temporomandibular joint, but not to detect condylar abnormalities.