It is well known that congenital anomalies are often associated with malformation of the inner, middle and external ear. In temporal bone studies, it has been found that abnormality of the facial nerve often occurs in patients with congenital aberrations. The temporal bone collections of the Teikyo University School of Medicine include 32 human temporal bones obtained from 19 infants ranging in age from one day to 7 months, who had chromosomal aberration and severe visceral anomalies. We histologically studied routinely processed sections of these temporal bones under a light microscope. Facial anomaly was observed in 20 of the 32 ears (63%). An abnormal course was observed in 18 ears (56%); 5 ears showed hypoplastic development, 4 showed displacement of geniculate ganglion cells into the internal auditory meatus, and 3 ears showed bifurcation. Abnormal course of the facial nerve was found in a significant number of ears with aural and mandibulal abnormalities (76%). However patients with multiple inner ear anomalies showed an abnormal course and hypoplasia of the facial nerve. There was no correlation between the incidence of facial abnormalities and inner ear anomalies. Key words: congenital anomaly, facial nerve, temporal bone
