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

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.

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).

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.

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.