Innervation of the human temporomandibular joint capsule and disc as revealed by immunohistochemistry for neurospecific markers

An immunohistochemical investigation for the neurospecific markers S-100 protein and protein gene product 9.5 was carried out on 12 healthy temporomandibular joint discs and capsules that were taken at autopsy from human adults. Large nerve trunks in the joint capsule and posterior disc ligament, as well as small nerve bundles and single nerves in almost all parts of the capsule, were heavily stained by anti-S-100 antiserum. The S-100 immunoreactive chondrocytes were also detected in the disc. Antiprotein gene product 9.5 similarly evidenced nerve fibers in the capsule and posterior disc ligament, and it also labeled a few small nerve bundles and a number of single fibers in the peripheral portions of the disc. No corpuscular or specialized endings were encountered in the specimens. These results give new support to the existence of a rich innervation of the human temporomandibular joint capsule and disc that should be further characterized with regard to type, function, and neuropeptide content.