The objective was to characterize the contralateral non-surgical temporomandibular joint (TMJ) in mice that had an opposing osteoarthrosis(OA)-like joint induced by unilateral partial discectomy.
TMJs on one side in mice were subjected to partial discectomy. Both surgical and contralateral non-surgical TMJs were collected at 4, 8, 12 and 16 weeks post-surgery for histological examination. The morphology of the articular cartilage of the condyle was evaluated using a scoring system.
A progression of articular cartilage degeneration was seen in the TMJs following unilateral partial discectomy, including increased proteoglycan staining in the extracellular matrix at 4 weeks, the appearance of chondrocyte clusters at 8 weeks, reduced proteoglycan staining and fibrillation at 12 weeks and the loss of articular cartilage at 16 weeks. In the contralateral non-surgical TMJs, increased proteoglycan staining occurred in the articular cartilage of the condyle at 8 weeks and continued to age.
The result indicated that OA-like changes in one TMJ by partial discectomy could initiate early-onset articular cartilage degeneration in the contralateral non-surgical TMJ in mice.