Micro‐CT Dimensions of the Stapes: Bilaterally Symmetrical, but Not Related to Mastoid Size

Abstract

Objectives: (1) Measure stapes height, footplate height (diameter perpendicular the crural plane), and footplate width (diameter in the plane of the crura) and to correlate these metrics between right and left sides. (2) Correlate stapes measurements with mastoid size, an indicator of childhood otitis media. Methods: From a group of 41 clinically normal ear cadavers, tissue blocks from the five crania with the largest mastoid pneumatization and 5 with smallest mastoid pneumatization were selected for micro computed tomography imaging. Using the ImageJ software package, a 3-dimensional model of each stapes was created to determine stapes height and footplate dimensions. Of 60 measurements sought, 52 were accomplished. Results: The mean stapes height was 3.43 mm (range, 3.18-3.82 mm). The mean stapes footplate width was 1.23 mm (range, 1.10-1.50 mm). The mean footplate height was 2.72 mm (range, 2.5-2.98 mm). Bilateral symmetry of dimensions was found, but there was no correlation with mastoid size. Conclusions: A wide range of stapes dimensions is confirmed by these specimens. Bilateral symmetry suggests that genetic influences may play a role in development. No correlation was found between stapes dimensions and mastoid size, suggesting that this local environmental aspect may not be related to its development.