Method:Twelve OA and Twelve age and gender matched controls, recruited from the university clinic and through advertisement, underwent a clinical diagnosis exam by an orofacial pain specialist using the RDC guidelines. Cone beam CT (CBCT) scans were obtained, as well as TMJ arthrocentesis and venipuncture. De-identified CBCTs were used to construct 3D models of the condyles. Levels of fifty biomarkers in synovial fluid and plasma samples, known to have a role in the OA inflammatory process, were measured with custom Quantibody protein microarrays. Shape Analysis MANCOVA was used test statistical correlations between biomarker levels and variations in condylar surface morphology, using surface mesh models composed of 4002 correspondent points.
Result: The OA average model was significantly smaller in all dimensions except its anterior surface, with the areas of greatest variance indicative on bone resorption being localized along the articular surface, particularly in the lateral pole. Synovial fluid levels of ANG, GDF15, TIMP-1, CXCL16, MMP-3 and MMP-7 cytokines gave interactions with the bone apposition of the anterior surface of the OA condyles. Plasma levels of ENA-78,MMP-3, PAI-1, VE-Cadherin, VEGF, GM-CSF, TGFb1, IFNg, TNFa, IL-1a, and IL-6 cytokines resulted in interactions with bone resorption and flattening reshaping of the lateral pole of the OA condyles. Expression levels of ANG were correlated with the articular surface morphology in healthy controls.
Conclusion: 3D assessment of the condylar morphology of the TMJ OA and control samples demonstrated areas of statistically significant difference localized to the superior articular surface, particularly the lateral pole. Shape Analysis MANCOVA successfully mapped variations in synovial fluid and plasma biomarkers to specific regions of anatomic variability in the OA group. Supported by NIDCR/NIBIB R01DE024450