Characteristic MR Findings of Rheumatoid Arthritis in the Temporomandibular Joints

 Rheumatoid arthritis (RA) is an autoimmune disease that develops not only in the elderly, but also from the third decade. This disease is known to spill over the temporomandibular joint from the whole body, however, there is a little attention of characteristic MR findings of RA in the temporomandibular joint. The purpose of this study was to investigate the characteristic MR findings of rheumatic arthritis in the temporomandibular joints.

 This study was approved by the university ethics committee (EC12-009). Nineteen patients (2 males, 17 females; 38 TMJs, age range 30-76 years, mean age of 55±15.5 years) were examined in this study. All cases have been diagnosed with rheumatic disease on blood laboratory tests and examination of the musculoskeletal system in our hospital from August 2006 to December 2013. MR images were evaluated the characteristic MR image of the TMJs such as disk position, disk morphology, joint effusion, bone marrow abnormality, osseous changes, synovial proliferation, erosion and deformity of articular eminence/glenoid fossa and lymph node in the neck. Assessment was diagnosed individually by two oral radiologists. These findings assessed rheumatic arthritis (RA) in the temporomandibular joints (TMJs). Methods of data analysis is average value.  

 RA in the temporomandibular joints showed 1) abnormal disk position (94.7%), 2) abnormal disk morphology (84.2%), 3) joint effusion (28.9%), 4) osseous changes of mandibular condyle (81.6%), 5)synovial proliferation (89.5%), 6) erosion of articular eminence/glenoid fossa (10.5%), 7) deformity of articular eminence/glenoid fossa (18.4%), 8) abnormal bone marrow signal of the mandibular condyle (84.2%), 9) swelling of lymph node in the neck (78.9%). 

 Characteristic MR findings of rheumatic arthritis in the temporomandibular joints showed abnormal disk position, abnormal disk morphology, joint effusion, osseous changes of mandibular condyle, synovial proliferation, not much erosion and deformity of articular eminence/glenoid fossa, abnormal bone marrow signal of the mandibular condyle, swelling of lymph node in the neck. These findings were suggested that characteristic MR findings of rheumatic arthritis in the temporomandibular joints.

 1) Larheim.T. A, et al: MR grading of temporomandibular joint fluid: association with disk displacement categories, condyle marrow abnormalities and pain. Int. J. Oral Maxillofac. Surg. 2001; 30: 104–112. 2) Helenius.L. M. J, et al: Clinical, radiographic and MRI findings of the temporomandibular joint in patients with different rheumatic diseases. Int. J. Oral Maxillofac. Surg. 2006; 35: 983–989.