Congenital Absence of the Oval Window

Abstract

A survey of 24 cases published so far is given. Congenital absence of the oval window is not a welldefined clinical entity. Other malformations of the middle ear structures are generally found. Hearing improvement was obtained in only one third of the cases previously published. Four new cases are presented, three of which were characterized also by other malformations apart from those concerning the ear, such as the Klippel-Feil syndrome, cleft palate and facial palsy. The hearing loss was bilateral and rather severe in two of the patients. In the other two cases it was unilateral but also severe. In all four cases explorative tympanotomy revealed different malformations of the middle ear in addition to the absence of the oval window. Hearing improvement was obtained in two patients, transient in one case, permanent in the other. Some em-bryological, audiological and kopho-surgical problems are discussed.