ABSTRACT
<p><b>OBJECTIVE</b>To investigate the level of urokinase-type plasminogen activator (uPA) and urokinase-type plasminogen activator receptor (uPAR) in synovial fluid of patients with temporomandibular disorders and to analyze their relation with temporomandibular disorders (TMD).</p><p><b>METHODS</b>Synovial fluid was obtained from 64 sides of 56 TMD patients and from 16 sides of 10 asymptomatic healthy volunteers (control). The concentrations of uPA and uPAR in the synovial fluid were measured by ELISA. Forty-eight sides of TMD were divided into 3 groups: arthrosis, structure disorder and osteoarthrosis, each including 16 sides.</p><p><b>RESULTS</b>The levels of uPA and uPAR were significantly higher in the synovial fluid of TMD patients than that in the control group (P < 0.05), and the level of uPA and uPAR in osteoarthrosis group was significantly higher than that in arthrosis and structure disorder group (P < 0.05). However, there was no difference in expression of uPA and uPAR between arthrosis and structure disorder groups (P > 0.05).</p><p><b>CONCLUSIONS</b>uPA and uPAR in the synovial fluid may play a role in the pathogenesis of TMD, and the level of uPA and uPAR in synovial fluid of TMD could be used as a biochemical markers to reflect pathological degree of TMD.</p>