Antioxidant capacity of synovial fluid in the temporomandibular joint correlated with radiological morphology of temporomandibular disorders.

We investigated the correlation between the antioxidant capacity of synovial fluid and radiological findings of intra-articular structures in patients with disorders of the temporomandibular joint (TMJ). We recruited 21 patients (9 men and 12 women, aged 18-84 years of age) with such disorders, excluding myofascial pain and dysfunction syndrome, or other muscular disorders. The clinical variables recorded included age, sex, interincisal distance, and visual analogue pain scores (VAS). Radiological findings were obtained from diagnostic arthrogram and cone-beam computed tomography (CT). The antioxidant capacity of the synovial fluid was measured by chemiluminescence. Eleven patients were radiologically diagnosed with closed lock, and the remaining 10 with no closed lock. An anchored intra-articular disc was most often seen on cone-beam CT (n=19) followed by perforated disc (n=7), osteoarthrosis (n=7), and anterior disc displacement without reduction (n=5). Although there were no significant differences between antioxidant capacity and age, sex, VAS, or any findings on cone-beam CT, antioxidant capacity was significantly decreased in the patients with closed lock compared with those who did not have closed lock (p=0.02). The results suggest an association between the oxidative stress of the synovial fluid and closed-lock in disorders of the TMJ.

The redox states of serum and synovial fluid of patients with temporomandibular joint disorders.

The redox states of albumin in serum and synovial fluid (SF) were analyzed in 35 female patients with temporomandibular joint disorders and 9 asymptomatic female healthy volunteers by high-performance liquid chromatographic (HPLC) analysis. Human serum albumin (HSA) is divided by HPLC analysis into three fractions: mercaptalbumin (HMA, reduced form) and nonmercaptalbumin (HNA-1 and HNA-2, oxidized forms). It was found that the characterized values of albumin in SF of patients with the disorders were the fraction of HMA (f (HMA), 65.8 +/- 9.1%), the fraction of HNA-1 (f (HNA-1), 31.3 +/- 8.8%), and the fraction of HNA-2 (f (HNA-2), 2.9 +/- 0.9%), respectively, and similarly the values of albumin in serum of same subjects were f (HMA), 79.4 +/- 4.0%; f (HNA-1), 18.7 +/- 3.8%; and f (HNA-2), 1.9 +/- 0.5%. The HNA fractions in SF were significantly higher than those in serum (p < 0.0001). The SF of patients and even control showed more oxidative condition compared with sera of the same subjects. Each fraction of SF showed significant difference in control (p < 0.05), and greater significance in patients (p < 0.0001). Furthermore, the HNA-2 fraction (f (HNA-2), 2.9 +/- 0.9%) in SF of the patients with temporomandibular joint disorders revealed a significantly higher value (p < 0.01) than that (f (HNA-2), 1.7 +/- 0.3%) of controls. These findings suggested that SF of the temporomandibular joint is more locally oxidized than serum; thus oxidative factors are concerned in the pathogenesis of the temporomandibular joint disorders. It was also suggested that synovial albumin may play a scavenging role against the intraarticular oxidative stress.

Synovial matrix metalloproteinase-2 in different stages of sheep temporomandibular joint osteoarthrosis.

PURPOSE: The purpose of this study was to test for the presence of matrix metalloproteinase (MMP) in synovial fluid of sheep with experimentally induced temporomandibular joint (TMJ) osteoarthrosis (OA) at various time intervals. MATERIALS AND METHODS: Twenty-one sheep were used in this study. TMJ OA was induced bilaterally in 18 sheep and 3 sheep were used as controls. Each experimental group had 3 sheep, and the groups were killed at 2, 4, 6, 8, 12, and 24 weeks postoperatively. Synovial fluid was collected at killing, and the joints were evaluated histologically. Gelatin zymography was performed to detect the presence of MMPs in the synovial fluid. RESULTS: TMJ OA gradually progressed over time. ProMMP-2 was detected in all experimental groups. However, the activated form of MMP-2 was only detected at 2 and 4 weeks postoperatively. CONCLUSION: Activated MMP-2 activity correlates with initial articular cartilage destruction rather than with the progression of OA in the sheep TMJ.