Clinical and magnetic resonance imaging findings of the temporomandibular joint and masticatory muscles in patients with rheumatoid arthritis

The aim of this study was to investigate the clinical, radiographic, and magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) and masticatory muscles in rheumatoid arthritis (RA) patients. Twenty-eight RA patients and 29 healthy subjects were participated in the study. The patient underwent clinical and laboratory investigation. DAS28 scores were calculated. Lateral panoramic radiography was performed to evaluate condylar erosion and condylar movement. Craniofacial MRI was performed to evaluate TMJ and masseter, medial and lateral pterygoid muscles' thickness, and cross-sectional area. It was found that the mean maximal interincisal distance, range of lateral, retrusive (P < 0.05) and protrusive motion were all lesser in RA group. Lateral panoramic radiography revealed a distinct erosion in 10.7% (3/28) and restricted condylar movement in 53.6% (15/28) of RA patients. Two RA patients demonstrating marked condylar erosion in lateral panoramic radiographs were RF negative and had DAS28 scores 3.41 and 4.61. MRI findings revealed condylar erosion and effusion in one RA patient and atrophic changes of masticatory muscles in another patient. There was no statistical significance between RA and healthy groups for the thickness and cross-sectional areas of the masticatory muscles. RA group revealed a strong linear relationship for the right and left muscle thickness and cross-sectional areas in regression analysis. TMJ symptoms are frequent findings and thought to be affected from mean disease duration in RA. Laboratory findings should be considered for disease activity-related TMJ involvement. RA patients did not present muscular atrophy or hypertrophy.