[Asymmetrical otocraniofacial syndrome (hemifacial microsomy) in discordant monozygotic twins. Otologic aspects]

The authors present a case of otocraniofacial syndrome with asymmetric involvement (hemifacial microsomia) in monozygotic twins discordant for the syndrome. Only a few cases of discordance in monozygotic twins have been previously describe in world literature. The occurrence of discordance in identical twins indicates the significance of exogenous factors. The patient had bilateral involvement right side being more severely involved than left side. Conductive hearing loss due to middle ear abnormalities was also present. Usefulness of tomographic examination to study structural ear abnormalities is emphasized, and some comments on the otologic involvement in this syndrome are made.