Morphometric analysis of the internal auditory canal by developmental change using three-dimensional computed tomography

Our aim was to analyze the developmental changes in the morphology of the internal auditory canal (IAC) in both children and adults to gain a three-dimensional understanding that could enhance various surgical approaches.

We retrospectively investigated 120 ears of 60 patients, ranging in age from birth to adulthood, using 3D-reconstruction data from normal temporal bone CT scans. The volume of the IAC in the temporal bone was reconstructed in 3D using Vworks version 4.0 (CyberMed, Seoul, Republic of Korea). Data were classified and evaluated by age group. IAC parameters were measured in the 3D objects using the axial, coronal, and sagittal sections of the CT scans.

The IAC volume significantly increased with aging from group 1 to group 2 (P = 0.01). The IAC volume also significantly correlated with the studied parameters (P = 0.001, for all). The Spearman’s rho values between the volume of IAC and the six parameters were as follows: Wp (r = 0.619), Wv (r = 0.763), Wm (r = 0.697), Dp (r = 0.541), Dm (r = 0.692), and Lpf (r = 0.659).

IAC volume continues to develop through adolescence. Understanding the normal growth pattern and three-dimensional morphology of the IAC would be helpful for different surgical approaches.