Effect of temporomandibular joint arthrocentesis on synovial fluid mediator level of tumor necrosis factor-alpha: implications for treatment outcome

Temporomandibular joint (TMJ) pain is a predominant sign and symptom in pat ients with temporomandibular disorder, and a common cause of chronic orofac ial pain. Arthrocentesis of the upper joint space proved to be effective in reducing TMJ-related pain and reestablishing normal mandibular range of mo vement in patients diagnosed for a 'closed lock'. Using the therapeutic app roach of arthrocentesis in TMJ-related instances of capsulitis/synovitis (C /S) with a recency of first pain onset of less than or equal to 6 months, t he purpose of the present study was to evaluate whether the TMJ-related var iable synovial fluid (SF) level of TNF-alpha may be linked to the cessation of related signs and symptoms associated with the performance of arthrocen tesis and hydraulic distension. In 23 patients with a specific temporomandi bular disorder diagnosis of unilateral C/S with a recency of first pain ons et of less than or equal to 6 months, TMJ SF aspirates were obtained from t he pain and contralateral non-pain sides immediately before and after arthr ocentesis. Visual analog scales were used for pre- and postoperative self-a ssessment of TMJ-related pain during function, while enzyme-linked immunoso rbent assays were applied for measurement of the tumor necrosis factor-alph a (TNF-alpha) concentration. With a mean SF TNF-alpha level of 13.91 ng/ml associated with the pain side, and a mean SF TNF-alpha level of 7.73 ng/ml associated with the non-pain side, a statistically significant difference w as found between the sample groups (P=0.001). Arthrocentesis led to a signi ficant intraoperative decrease of the respective preoperative SF TNF-alpha levels, namely 61.64% (P=0.000) on the pain side and 89.50% (P=0.000) on th e non-pain side, while reduction of TMJ-related pain during function was 73 .17% (P=0.000). Clinical evaluation showed a significant reduction in the p revalence of TMJ-related diagnoses of C/S (P<0.001). Then was no change in the prevalence of associated TMJ-related diagnoses of internal derangement. In view of the fact that the described technique of TMJ SF analysis may be suggested as a valuable diagnostic method for the detection of biochemical SF events, the results of this study should encourage research in its pote ntial uses so that it can become established as a reliable diagnostic appro ach. Further, the findings may support the concept of bilateral arthrocente sis to be effective in the treatment of patients with a unilateral specific TMD diagnosis of non-chronic C/S.