Interactions between the middle and inner ear in patients with ear malformations

Abstract

We sought to further evaluate interactions between the middle and inner ear during embryogenesis resulting in ear malformations, and undertook a clinical investigation of such malformations. Four ear malformation syndromes with different aetiologies and an animal model of known aetiology were compared. By comparing patients with thalidomide induced ear malformations, where the exact time of administration of the teratogen was known, the sensitive time for ear development was obtained. The severity of the ear malformation was related to the time period during which the ear formed. Thus, patients with mandibulofacial dysostosis and hemifacial microsomia with severe middle ear malformations, were damaged during embryonic days 21–24. Patients with CHARGE association with minor middle ear malformations but severe inner ear malformations were damaged during embryonic days 24–29. Therefore, malformations of the middle and inner ear occur during a short time period of embryogenesis. A plausible explanation for the different malformations is related to disturbed or reduced neural crest cell migration during embryogenesis.

• ear malformations
• syndromes
• genetic
• teratogen
• neural crest