Magnetic resonance imaging versus musculoskeletal ultrasound in the evaluation of temporomandibular joint in rheumatoid arthritis patients

Aim of the work: To evaluate temporomandibular joint (TMJ) affection in rheumatoid arthritis (RA) patients by magnetic resonance imaging (MRI) versus musculoskeletal ultrasound (MSUS) and to correlate the findings with clinical manifestations, disease activity and functional status. Patients and methods: Twenty RA patients (40 TMJ) were included in this study. Disease activity score 28 (DAS28) was assessed and functional status by modified health assessment questionnaire (mHAQ). The TMJs were assessed clinically and functionally according to the Fonesca’s questionnaire. Radiological assessment of the TMJ was performed using panorama X-ray, MSUS and MRI. Results: The patients mean age was 47.3 ± 10.03 with a F:M 9:1. Out of 40 TMJs 27 (67.5%) were symptomatic; pain/tenderness in 67.5%, limited mouth opening in 65% and sounds in 47.5%. MRI was superior in detection of TMJ abnormalities compared with MSUS (82.5% vs 77.5%, respectively). The frequencies of TMJ erosions detected by MRI, MSUS and panorama were 80%, 57.5% and 27.5% respectively (p = 0.0001). TMJ effusion and disc displacement were comparable by MRI and MSUS (67.5% and 62.5%; p = 0.64 and 57.5% and 52.5%; p = 0.5,respectively). Only the effusion and disc displacement significantly correlated with the DAS28 and mHAQ. Only the erosions detected by MSUS did not significantly correlate with the Fonesca’s questionnaire. Conclusion: Detection of TMJ abnormalities tended to be higher by MRI than by MSUS yet with no difference between both modalities. TMJ erosions, effusion and disc displacement were common in RA patients as detected by MRI and MSUS. Also both were helpful in detecting subclinical TMJ radiographic abnormalities in RA patients