Immunohistochemical study of the rat mandibular condylar cartilage under occlusal alteration caused by tooth extraction

Abstract

Although it is reasonable to believe that alteration of occlusion may cause or exacerbate temporomandibular disorders, the exact role of occlusion is still unknown. I immunohistochemically examined the changes that occurred after tooth extraction in rat mandibular condylar cartilage. Unilateral maxillary molars were extracted from rats, and the temporomandibular joints were resected after 1, 2, 3 or 6 months. The tissues were fixed with paraformaldehyde, embedded in paraffin after decalcification with EDTA, and then prepared in serial sections for immunohistochemjcal examination for types I, II and X collagen, chondroitin 4-sulfate, chondroitin 6-sulfate, keratan sulfate and dermatan sulfate proteoglycan. In the experimental rats, staining for types I and X collagen, C4S, KS and DSPG was stronger, whereas that for C6S was weaker, than in the controls. These findings seem to indicate a loss of elasticity in the mandibular condylar cartilage.