ELEVATED LEVELS OF NITRIC-OXIDE IN SYNOVIAL-FLUID FROM PATIENTS WITH TEMPOROMANDIBULAR DISORDERS

Objective. The objective of this study was to measure nitric oxide act ivity in synovial fluid samples taken from patients with temporomandib ular disorders. Study design. We investigated six volunteers without s ymptoms and 56 patients with temporomandibular disorders. Nitric oxide activity was measured in temporomandibular joint synovial fluid with a highly sensitive and specific chemiluminescence detection method. Re sults. A detectable nitrite concentration was found in only 1 of 10 jo ints in the control group. Measurable levels (>0.001 mol/l) of nitrite s in the synovial fluid were found in 8 (72.7%) of 11 joints with disk derangement with clicking, 24 (85.7%) of 28 joints with disk derangem ent with locking, and all 26 (100%) joints with osteoarthritis. The me an nitrite concentrations in the temporomandibular joint synovial flui d in the disk derangement with clicking, disk derangement with locking , and osteoarthritis groups were significantly higher than that in the control group (p < 0.05, p < 0.001, p < 0.001, respectively).Conclusi ons. These data clearly show increased nitric oxide production in cert ain temporomandibular disorders and suggest that nitric oxide may play a role in the pathogenesis of synovitis and degenerative changes of c artilaginous tissue and bone of the temporomandibular joint.