Cochlear Rotation and its Relevance to Cochlear Implantation

Abstract Objectives: To investigate changes in cochlear orientation with age and discuss the implications of any change with respect to cochlear implantation. Study Design: Cross-sectional study of computerized tomography scans of the temporal bones in patients with no congenital abnormalities. Patients: 159 patients were included in the study making a total of 318 ears. The age range was nine months to eighty five years. Intervention: Axial compututed tomography scans showing the basal turn of the cochlea were identified. The angle of the basal turn of the cochlea was measured by drawing a line through the long axis of the basal turn and measuring its angle with a line drawn through the midsagittal plane. The patients were grouped according to age and a one way analysis of variance was used to identify any statistically significant change in basal turn angulation. Inter- and intra-observer errors were calculated and presented as repeatability co-efficients. The basal turn angles of 3 difficult cases of c...