The objective of this study was to investigate the expression of matrilin-1 in arthritic articular cartilage of the mandibular condyle by means of immunohistochemical methods.
Condylar cartilage specimens were obtained from temporomandibular joints (TMJs) of 12 patients with arthritis (osteoarthritis and internal derangement) (mean age 51.8 years; age range 28-71 years) and four patients with TMJ ankylosis (mean age 44.0 years; age range 16-64 years), diagnosed clinically and with imaging examinations. Paraffin sections were immunostained with anti-matrilin-1 antibodies.
Matrilin-1 expression was detected in both patient groups with TMJ ankylosis and arthritis, and the level was remarkably higher in arthritic cartilage. The mean percentage of matrilin-1-producing cells to the total chondrocytes was significantly (P < 0.05) greater in the arthritic group (43.9 +/- 19.2%) than in subjects with TMJ ankylosis (28.0 +/- 8.7%).
Articular chondrocytes in the TMJ condyle can express matrilin-1 and the expression is enhanced in arthritic cartilage, suggesting a presence of functional or adaptive remodeling in the condyle in response to degenerative changes in the TMJ structures.