Comparison of the effectiveness of arthrocentesis in acute and chronic closed lock: analysis of clinical and arthroscopic findings.

The objective of this study was to investigate the effectiveness of temporomandibular joint arthrocentesis in acute and chronic closed lock patients. Eighteen patients with closed lock of the temporomandibular joint (TMJ) were treated with fine needle fiber arthroscopic observation following arthrocentesis. Maximal mouth opening (MMO) and intensity of pain (VAS) were evaluated at pretreatment and each posttreatment appointment (one week, one month, three months following treatment). The clinical and arthroscopic findings were analyzed categorizing two groups into: good (A) and poor (B) groups. At pretreatment there was no significance relative to age or the mean MMO and VAS between the groups, but the mean of duration of the symptoms in group B was significantly longer than in group A (P < 0.03). Group B showed more severe synovitis, adhesions, and chondromalacia than group A (P < 0.01). Results suggest that arthrocentesis is more effective in closed lock of short duration where there is less severe synovitis, adhesions, and chondromalacia.