Abnormal mandibular growth and the condylar cartilage.

Deviations in the growth of the mandibular condyle can affect both the functional occlusion and the aesthetic appearance of the face. The reasons for these growth deviations are numerous and often entail complex sequences of malfunction at the cellular level. The aim of this review is to summarize recent progress in the understanding of pathological alterations occurring during childhood and adolescence that affect the temporomandibular joint (TMJ) and, hence, result in disorders of mandibular growth. Pathological conditions taken into account are subdivided into (1) congenital malformations with associated growth disorders, (2) primary growth disorders, and (3) acquired diseases or trauma with associated growth disorders. Among the congenital malformations, hemifacial microsomia (HFM) appears to be the principal syndrome entailing severe growth disturbances, whereas growth abnormalities occurring in conjunction with other craniofacial dysplasias seem far less prominent than could be anticipated based on their often disfiguring nature. Hemimandibular hyperplasia and elongation undoubtedly constitute the most obscure conditions that are associated with prominent, often unilateral, abnormalities of condylar, and mandibular growth. Finally, disturbances of mandibular growth as a result of juvenile idiopathic arthritis (JIA) and condylar fractures seem to be direct consequences of inflammatory and/or mechanical damage to the condylar cartilage.