Bilateral mandibular condylysis-a morphanalytic diagnosis.

Four cases of bilateral mandibular condylysis are presented. The condition does not appear to be included in current teaching or existing nomenclature and consists of an acquired absence of the mandibular condyles, unassociated with temporomandibular ankylosis or aural/facial anomalies. In the literature of condylar maldevelopment four published cases appear to justify reclassification as bilateral mandibular condylysis, bringing the recorded total to eight. Whereas previous writers have regarded the condition as a prenatal condylar aplasia or hypoplasia, morphanalysis studies of the four current cases have shown that the probable aetiology is postnatal local disturbance in the condylar region. The term condylysis has been chosen to emphasise the locally destructive (or lytic) mechanism which appears to be involved. Mandibular condylysis is distinguished from condylar aplasia by its non-association with aural/facial anomalies and because normal development appears to proceed until the lytic event occurs. It is further distinguished from primary and secondary condylar hypoplasia because the condyle is absent rather than small, because normal development appears to proceed until the lytic event occurs and because of its non-association with aural/facial anomalies or temporomandibular ankylosis.