Hemifacial microsomia

Congenital abnormalities of face emerge as a constellation of malformation of structures which arise from the first and the second branchial arch and the intervening first pharyngeal pouch and the primordia of the temporal bone. When fully expressed, a patient with hemifacial microsomia [Syn: otomandibular dysostosis] exhibits usually unilaterally under developed external or middle ear, mandible, zygoma, maxilla, temporal bone, facial muscles, muscles of masticiation. Many cases however, have been reported where the syndrom is not fully expressed (Crabb 1965).