The age-related positional and orientational changes of the human cochlea

Conclusion: The cochleae of children over 6 years old and adults displaced more outward, backward, and downward in comparison with those of children under 6 years. However, the cochlear orientation does not significantly change during postnatal development. Adjacent structures correlated with the cochlear position. Objective: To test whether the cochlear position and orientation, which are important in cochlea implant surgery, change during postnatal development. Methods: CT images of both ears of 76 human subjects were studied. They were divided into three groups: group A (1-6 years old), group B (7-18 years old), and group C (>18 years old). Results: The distances from the cochlea to the median sagittal and coronal planes in group A were smaller than those in group B and group C (p < 0.05), but the distance from it to the Frankfurt plane in group A was larger than that in group C (p < 0.05). The volume of the temporal bone pneumatization and the positions of the jugular bulb and the intrapetrous internal carotid artery positively correlated with the cochlear position (p < 0.05). There were no statistically significant differences in the angles between the central axis of the cochlea and these coordinate planes among age groups.