14 cases (16 joints) with temporomandibular joint dysfunction syndrome (TMJDS) were included in the present study. All the patients had severe pain of the joint for a long time and the conventional therapy was not effective. The operative and pathological findings of the 14 cases showed that synovitis secondary to microtrauma of the joint really existed and might be one of the reasons causing the severe pain of the joint in some patients with TMJDS.