A longitudinal study on the osteoarthritic change of the temporomandibular joint based on 1-year follow-up computed tomography

This study aims to report the results of a 1-year computed tomographic (CT) follow up of 54 temporomandibular joints (TMJs) affected by osteoarthritis (OA) and to provide longitudinal information on changes in OA and its relationship with clinical signs and symptoms. TMJ OA was diagnosed by history, clinical and CT examinations. The second CT examination was done after about 1 year of conservative treatment. Joints were divided into three groups labeled as no change, improved CT, and worsened CT groups depending on the longitudinal bony change of OA observed in the CT. The sex distribution, mean age, joint noise, subjective pain, joint tenderness, masticatory muscle tenderness, and improvement of subjective symptoms were not different between the groups at the first and second examination, while maximum (p < 0.01) and painless mouth opening range (p < 0.001) at the first examination were both smaller in the worsened CT group. Although the clinical signs and symptoms of OA were improved in 40 joints, 74.1%, at 7.2 ± 4.6 months, the amount if improvement did not differ between the groups. The extent of the destructive change of the condyle was highest in the improved CT group at the first (p < 0.001) and in the worsened CT group at the second examination (p < 0.001). These results imply that the prognosis of OA changes may be independent of the clinical signs and symptoms. More specific longitudinal information as regards OA changes of the TMJ based on a larger sample and a longer follow-up period would be likely to provide a better understanding of TMJ OA.