Click on image to view larger version.
Figure 4. Safranin-O-stained sections of the rabbit TMJs after excessive mechanical stress application. (A) Control TMJ articular cartilage (original magnification, 40X). (B) Experimental TMJ articular cartilage at 1 day after mechanical stress application (original magnification, 40X). Dramatic SO staining reduction, especially at the articular surface layer of the cartilage (sr), was observed. (C,D,E) Experimental TMJ articular cartilage at 7 days after mechanical stress application (original magnification, 40X). Strong SO staining was observed in the sites of nested proliferation of chondrocytes (chondrocyte island, ci) in the subchondral bone layer of the central and posterior aspects of the condyle (D,E) and peripheral chondrocyte proliferation (pr) covering the anterior surface of the condyle (C). (F) Higher magnification of the area in the rectangle seen in panel D (original magnification, 200X). Hypertrophic chondrocytes and cartilage matrix were being replaced by endothelial cells and osteogenic cells.
