Salivary gland and temporomandibular joint involvement in rheumatoid arthritis: relation to disease activity

OBJECTIVES: To study temporomandibular joint (TMJ) involvement, salivary gland dysfunction and oral mucosal lesions in rheumatoid arthritis (RA), and to investigate the relationship to general disease activity. SUBJECTS AND METHODS: The TMJ dysfunction index (D(i)), mean salivary flow and disease activity score (DAS28), were calculated for 50 RA-patients, and 23 non-RA patients (controls). RESULTS: Median D(i) was 5.5 (range: 0-21) for the RA-patients compared with 2.0 (range: 0-9) for the controls (P < 0.0001). Pain on movement of the TMJ (P = 0.015), muscular pain (P = 0.006), TMJ pain (P = 0.019) and D(i) as a total (P = 0.009), significantly correlated with DAS28. Mean resting whole saliva (RWS) flow was 2.6 (s.d. 2.4) ml per 15 min for the RA-patients and 4.5 (s.d. 3.0) for the controls (P = 0.003). RWS correlated positively with haemoglobin (P = 0.021) and negatively with Westergren erythrocyte sedimentation rate (ESR) (P = 0.029). No major differences in frequency of oral mucosal lesions were seen between RA-patients and controls. CONCLUSIONS: Higher frequency of TMJ and salivary gland dysfunction in RA-patients compared with controls has been demonstrated. RA disease activity is associated with hyposalivation and TMJ dysfunction.