Abstract: Objective This study aims to evaluate the effectiveness of arthrocentesis on Wilkes Ⅲ stage patients. Clinical examinations and magnetic resonance imaging (MRI) findings before treatment and six months after treatment were compared and analyzed. Methods A total of 137 outpatients diagnosed with temporomandibular joint internal derangement (TMJID) associated with Wilkes Ⅲ stage through clinical examination and MRI findings from January 2013 to December 2013 were randomly included. All the patients were successfully treated with arthrocentesis. Moreover, all the patients accepted clinical and MRI examination before arthrocentesis treatment and six months after. Clinical examination included visual analogue scale and opening degree, whereas MRI examination included articular disc morphology and effusion in the upper compartments. Statistical analysis was performed using SPSS 20.0. Results Results showed that the average score of visual analogue scale six months after treatment was significantly lower than that before treatment (P<0.05). The success rate was 78.1% (107/137). The rate of disc deformity after arthrocentesis treatment was higher than that before the treatment. By contrast, the positive rate of effusion after arthrocentesis was significantly lower than that before the treatment (P<0.05). Bilaminar zone adaptive changes (disk-like) were found in seven cases (5.1%, 7/137) after treatment. Conclusion Arthrocentesis could effectively relieve pain of the TMJID patients. Furthermore, MRI results indicated that arthrocentesis could significantly decrease articular effusion. Arthrocentesis was effective for the treatment of Wilkes Ⅲ stage in the short term. Adaptive changes in bilaminar zone occurred in a few patients. However, serious disc deformity with the passage of time is a trend that has been observed.

Key words: temporomandibular joint internal derangement, articular disc, arthrocentesis, magnetic resonance imaging