[High-resolution computed tomography evaluation of congenital anomalies of the temporal bone].

High-resolution computed tomography (HRCT) was used to study 23 patients with congenital temporal bone deformities. One patient had an inner ear abnormality and 3 patients were combined together with inner, middle and external ear malformations. Embryological development of the outer and middle ears is linked. Development of the inner ear occurs independently. These abnormalities included vestibule dilatation in 2 patients, a lateral semicircular canal defect in 1 case, dilatation of lateral and superior semicircular canals in 1 patient, only dilatation of the lateral semicircular canal in 1 case, oval-window non-development in 3 cases, oval aqueduct dilatation in 1 patient and inner ear abnormalities in 1 case. The study also included 17 cases of unilateral external auditory canal atresia, 5 cases of bilateral atresia, and 1 normal external auditory canal. There were 8 cases of unilateral and 2 cases of bilateral bony atresia. There were 9 unilateral and 1 bilateral cases of membranous atresia. Two cases had bony atresia on one side, with contralateral membranous atresia on the other. Nine unilateral and 2 bilateral cases were positioned superiorly and posteriorly of the mandibular condyle. Thick atresic plate were found in 10 unilateral and 2 bilateral cases. Small tympanic cavities were found in 12 unilateral and 2 bilateral patients; 7 unilateral and 2 bilateral cases had acellular and hypoplastic mastoids. Ossicular deformities were seen in 14 unilateral and 2 bilateral patients. One patient had no ossicle. Anteriorly located descending facial nerve canal was noted in 9 unilateral and 2 bilateral cases. Congenital cholesteatoma was identified in 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)