Prognostic factors in arthrocentesis of the temporomandibular joint: Comparison of bradykinin, leukotriene B4, prostaglandin E2, and substance P level in synovial fluid between successful and unsuccessful cases.

Purpose: To compare levels of bradykinin (BK), leukotriene B4 (LTB4), prostaglandin E2 (PGE2), and substance P (SP) between successful and unsuccessful cases of arthrocentesis of temporomandibular joint disorders (TMDs).
Patients and Methods: A total of 66 joints in 66 patients with TMDs who underwent arthrocentesis were evaluated in this study. Synovial fluid diluted with saline solution was aspirated from the superior joint compartment before arthrocentesis and their concentrations of BK, LTB4, PGE2, and SP were determined by enzyme-linked immunosorbent assay. The differences in the detection rate and concentration of each mediator between successful cases and unsuccessful cases of arthrocentesis were analyzed statistically.
Results: Arthrocentesis was successful for 77% (51/66) of the joints. The mean detection rate of LTB4 was significantly (P < .05) higher in the unsuccessful cases (47%) than in the successful cases (16%). The mean concentration of BK was significantly (P < .0005) higher in the unsuccessful cases (425 pg/mL) than in the successful cases (144 pg/mL). There was also a statistical correlation between the detection of LTB4 and PGE2 (P < .01).
Conclusions: Increased levels of BK and LTB4 in the synovial fluid of patients with TMDs may indicate that arthrocentesis is less likely to be a successful treatment.