Structure features of the temporal bone in patients with acquired post-inflammatory atresia of the external auditory canal

Objective: Comparative analysis of the structure of the external auditory canal (EAC) according to computed tomography (CT) scans of the temporal bones in patients with acquired post-inflammatory atresia of the EAC and patients with safe chronic suppurative otitis media (SCSOM) without atresia. Patients and methods: 42 patients (43 ears) with acquired post-inflammatory atresia of the EAC and 11 patients (22 ears) with bilateral SCSOM without acquired atresia were included in the study. Based on the original axial СT images and multi-planar reformation images were measured: thickness of the anterior wall in bony part of EAC; anterior tympanomeatal angle and the distance from the lateral process of the malleus to the anterior wall of an EAC; lumen of the EAC in front of the tympanic sulcus. Results: The lumen of the bone part of the EAC in patients with acquired post-inflammatory atresia is 17,0% less than in patients with SCSOM without atresia; patients with acquired post-inflammatory atresia have a more acute anterior tympanomeatal angle (33° versus 68°) than patients with SCSOM without atresia. The thickness of the anterior wall of the EAC in the bone part in patients with acquired post-inflammatory atresia of the EAC does not statistically differ from the analogous parameter in patients with SCSOM without atresia. Conclusion: The revealed results indirectly indicate the presence of certain features of the structure of the external ear in patients with acquired post-inflammatory atresia of the EAC such as narrower anterior tympanomeatal angle and lumen of the bone part. These features of the EAC structure may contribute to the more likely development of post-inflammatory atresia development.