Temporomandibular joint (TMJ) disorders are relatively common, but their pathophysiology is not fully understood. Research has demonstrated the presence of reactive oxidative radical species and various inflammatory mediators in TMJ synovial fluid; however, disease staging and clinical symptoms have not been correlated. The present study investigated the relationship of inflammatory mediators and matrix degradation components in patients ( n = 28 females) with various Wilkes stages of TMJ disease and to clinical symptoms. Synovial fluid samples were obtained during arthroscopy and processed to remove cells. Total protein concentration was determined prior to protein-specific assay by multiplex protein array. Molecular indicators of inflammation and degradation were correlated with Wilkes classification and clinical pain reports. Pre-operative pain was rated high and significantly diminished post-operatively in all patients, irrespective of diagnosis. IFN-gamma and COX-2 increased significantly ( P = 0.02) with severity of Wilkes classification. TNF-alpha was also elevated in all groups except those with a normal joint, with a positive linear trend for significance ( P = 0.08). Matrix degradation represented by MMP-2 and 9 levels demonstrated a significant linear trend for increase that was not significant for median differences. These data demonstrate an increase in inflammation and degradation processes according to severity of Wilkes staging. Monitoring mediator levels may be predictive of disease progression and provide therapeutic targets.

Abbreviations: n = number; rpm = revolutions per minute; C = Celsius; IFN-gamma = interferon-gamma; COX-2 = cyclooxygenase-2; TNF-alpha = tumor necrosis factor-alpha; IL-6 = interleukin-6; MMP2 = matrix metalloproteinase-2.

Conflict of interest: None declared.