Collagen type in dysfunctional temporomandibular joint disks.

Controlled studies were undertaken to ascertain the nature of the fibrous tissue component of surgically removed dysfunctional human temporomandibular joint disks. Each disk was divided into several parts and dissociative methods were used to extract collagenous residues. The resultant residues were digested with cyanogen bromide and the obtained soluble peptides were characterized by their electrophoretic mobility on polyacrylamide slab gels. The separated peptides were then scanned on a laser densitometer. Type III collagen was identified in samples taken from both the women's and the men's posterior disk attachment tissues. The amount of type III collagen in the women's attachments was approximately twice that found in the men's and both of these quantities were greater than those previously found in nondysfunctional tissues. The finding that there was more type III collagen in the posterior attachments of the women's chronically damaged disks may indicate that these tissues in women are less able to withstand functional loading.