Facial Canal Anatomy in Patients with Mandibulofacial Dysostosis: Comparison with Respect to the Severities of Microtia and Middle Ear Deformity

Abstract

To study the difference in the facial canal anatomy in terms of the severity of microtia and deformity of the middle ear in patients with mandibulofacial dysostosis using high-resolution computed tomography. Retrospective analyses. The study was carried out at the Department of Otorhinolaryngology, University of Tokyo, Tokyo, Japan. Thirty-six ears of 18 patients with mandibulofacial dysostosis were examined by high-resolution computed tomography. These ears were graded based on the Marx classification and Jahrsdoerfer scoring systems. The high-resolution computed tomography findings and age distribution of each group were compared with those of other groups by multiple comparison using Tukey's honestly significant difference test. The course of the facial nerve was not significantly different in terms of the severity of microtia and deformity of the middle ear. The bony cochlea in the patients with mandibulofacial dysostosis was displaced by a mean value of 2 mm more anteriorly and a mean value of 0.7 mm shallower than that in the cases with normal auricles. The facial nerve of patients with mandibulofacial dysostosis is displaced more anterolaterally than that of the cases with normal auricles; however, the auricle anomaly is not severe.