In 1985, the dissertation ‘Temporomandibular joint. Articular cartilage structure and function’ was published. Much was known at the time concerning the (clinical) pathogenesis of osteoarthrosis of the temporomandibular joint, the associated radiographical characteristics and the results of nonsurgical treatment. Little was known, however, concerning the processes that lead to the loss of bone tissue and other degenerative changes. The current idea that osteoarthrosis was histopathologically characterized by defects in the joint surfaces did not seem to apply to temporomandibular joints. In temporomandibular joints, the phenomenon was recognized of degenerative changes in the deeper layers of the articular cartilage and the subchondral bone, while the articular surface could be microscopically intact. A dislocated articular disc was seen as part of the disease osteoarthrosis. Clear insight into the origins of osteoarthrosis was not achieved.