Localization of keratan sulphate and chondroitin-6-sulphate on the anteriorly displaced human temporomandibular joint disc--histological and immunohistochemical analysis.

The aetiology of temporomandibular joint (TMJ) disc displacement has been investigated using human post-mortem material. Twenty TMJ specimens were used for a histological procedure with haematoxylin and eosin staining and orcein staining. Immunohistological analysis with chondroitin-6-sulphate and keratan sulphate was also carried out on the same specimens. Immunohistochemically, the specific localization of chondroitin-6-sulphate and keratan sulphate in the antero-medial parts of the anteriorly displaced deformed TMJ disc, which may be load-bearing areas, was observed. Orcein staining revealed that specific elastic fibres pulling the anterior band and stretching the disc continuously, may be an important factor in disc displacement. On the basis of these results, we were able to propose a significant new hypothesis for the aetiology of disc displacement.