[Substance P in synovial fluid in patients with temporomandibular joint dysfunction syndrome]

Radioimmunoassay technique was used to measure substance P levels in synovial fluid samples from thirty patients with temporomandibular joint dysfunction syndrome (TMJDS). Twenty-four samples (80%) were found to have substance P. Concentrations of substance P in the synovial fluid from patients with painful TMJDS were higher than those patients without pain (P < 0.05). The study supported the evidence for the secondary synovitis in painful TMJDS, and suggested that the nervous system play a role in the pathophysiology of TMJDS.