The otologic manifestations of mandibulofacial dysostosis.

Sixteen patients (32 ears) with diagnoses of mandibulofacial dysostosis were reviewed. The characteristic otologic manifestations of the syndrome were delineated, found to be bilateral, and consist of the following: 1. Mild symmetric deformity of the auricle (grade 1 microtia). 2. Agenesis or hypoplastic development of the mastoid and mastoid antrum. 3. Absence of the external auditory canal. 4. Marked narrowing or agenesis of the middle ear cleft. 5. Agenesis or severe malformation of the malleus and incus. When present, the malleus and incus are most often rudimentary, fused to form a conglomerate mass, and ankylosed to either the atretic plate, epitympanum, or both. 6. Stapedial malformations which usually consist of a deformed suprastructure. 7. Frequently the tegmen assumes a more inferior (low lying) position than normal. 8. Occasionally, the facial nerve pursues an abnormal course and is located more anteriorly than would be expected. 9. A normal inner ear. 10. Normal bone conduction with a marked (greater than 50 dB) conductive hearing loss. 11. Marked disparity between the degree of auricular deformity (mild; grade 1 microtia) and the degree of deformity of the remaining first and second branchial arch derivatives that constitute the external and middle ears (severe).