MICROTIA GRADE AS AN INDICATOR OF MIDDLE-EAR DEVELOPMENT IN AURAL ATRESIA

Objective: To correlate the appearance of the external ear with the de velopment of the middle ear in patients with congenital aural atresia. Design: Retrospective analysis of patients with congenital aural atre sia. Obtain the microtia grades assigned to affected ears and correlat e them with atresia scores that describe the degree of the middle ear malformation. Setting: University of Texas-Houston Otolaryngology Clin ic (1988 to 1992). Patients: A total of 199 ears with congenital micro tia and aural atresia and 25 ears with canal stenosis without microtia were identified, all of which had been previously evaluated by high-r esolution computed tomography of the temporal bone, and then assigned an atresia score. Patients with Treacher Collins syndrome were not inc luded in our study. Results: The average atresia score in cases with g rade I microtia was 8.5; grade II microtia, 7.2; and grade III microti a, 5.9. In cases with canal stenosis without microtia, the average atr esia score was 8.3. Conclusion: The better developed the external ear, the better developed the middle ear.