Topographical distribution of sulfated glycosaminoglycans in the surface layers of the human temporomandibular joint. A histochemical study of an autopsy material.

The right temporomandibular joint (TMJ) was removed at autopsy from 18 individuals and the articular surfaces were scored for macroscopic lesions. Soft tissue specimens were cut out of the medial, lateral and posterior parts of the temporal and condylar components and frozen. The sections were stained with toluidine blue (1-N HCl solution) and with alcian blue (CEC method) for sulfated glycosaminoglycans. The sections were examined for inter- and pericellular metachromasia and alcian blue staining. Macroscopic surface lesions were found in 14 of the joints. The highest score of interand pericellular metachromasia was found in the anterior parts of the joints and a negative correlation was found between the score of surface lesions and that of intercellular metachromasia. Pericellular metachromasia was found mainly in the mineralized cartilage and cartilage layers of the articular surface. Although the CEC values of pericellular staining commonly reached a level indicating the presence of keratan sulfate, the majority of the CEC values found corresponded to those of chondroitin-dermatan sulfate. It was concluded that sulfated GAG are localized mainly to the anterior part of the TMJ and that macroscopic TMJ surface lesions are associated with a reduction of sulfated glycosaminoglycans.