1993 Volume 27 Issue 2 Pages 107-111
β-Glycosidases (N-acetyl-β-glucosaminidase, N-acetyl-β-galactosaminidase, β-glucuronidase) were assayed in temporomandibular joint (TMJ) synovial fluid obtained from 23 patients with closed lock TMJ internal derangement (ID), four with closed-lock TMJ osteoarthritis (OA), and 13 with normal controls (N). Synovial fluid was collected from the upper joint space after injecting 1.5 ml of 1% lidocaine three times. The specific activity of N-acetyl-β-glucosaminidase increased significantly both with ID (p<0.01) and with OA (p<0.001), along with increases in the activity of N-acetyl-β-galactosaminidase (p<0.05 with ID and p<0.01 with OA) and in β-glucuronidase (p<0.05 both with ID and OA). The N-acetyl-β-glucosaminidase activity with OA was also significantly higher (p<0.001) than with ID. These findings suggest that N-acetyl-β-glucosaminidase activity in the TMJ synovial fluid reflects the degree of TMJ dysfunction.