Condylar hyperplasia. A clinico-pathological analysis of 22 cases.

A series of 22 cases of unilateral condylar hyperplasia is presented with the emphasis on histopathological aspects. It is concluded that there are two types of condylar hyperplasia. The first manifests itself in the adolescent or the young adult and represents an exaggerated, normally proceeding growth and maturation process. The histological structure of the condyle in these cases is age-dependent as is shown by a conversion of hyaline growth cartilage into fibrocartilage occurring at about 20 years of age. The second type of condylar hyperplasia, seen in older people, probably represents reactive growth as a response to an eliciting agent that mostly can be identified. In these cases the histological architecture of the condyle is distorted by large masses of hyaline cartilage while there are concomitant degenerative changes in the form of arthrosis. In contrast to the patients suffering from the first type of condylar hyperplasia, the latter ones complain of additional joint symptoms, mostly pain. Moreover it is concluded that joint scintigraphy does not clearly discriminate between genuine condylar hyperplasia and reactive processes due to arthrosis, which may have clinical implications.