Quantitative Assessment of Craniofacial Changes Following Facial Feminization Surgery Using Computerized Tomography Segmentation

Abstract

Purpose:

Facial feminization surgery (FFS) encompasses procedures aimed at modifying facial features to align with a more feminine aesthetic. While qualitative assessments of outcomes are common, quantitative evaluations remain limited. This study quantified changes in forehead, chin, and gonial angle morphology following FFS using computed tomography (CT) segmentation.

Methods:

Patients who underwent FFS in an academic medical center from 2020 to 2024 with pre- and postoperative CT scans were included. CT segmentations of the forehead, chin, and gonial angles were performed using Mimics software. Volume and surface area were assessed. Additional measurements included frontonasal and bossing angles for the forehead, sagittal and vertical projection for the chin, and the intergonial–interzygomatic distance ratio for the gonial angles. Paired t-tests compared pre- and postoperative measurements.

Results:

Eighty patients were included. Forehead volume decreased by 14.44%, surface area by 6.31%, frontonasal angle by 6.78%, and bossing angle by 25.71% (all p < 0.05). Chin volume decreased by 3.77% (p = 0.003), while surface area decreased by 2.04% (p = 0.06). Sagittal chin projection increased by 8.92% (p < 0.001), but vertical projection did not change significantly. Gonial angle volume decreased by 10.30%, surface area by 5.41%, and intergonial–interzygomatic distance ratio decreased from 0.77 to 0.76 (all p < 0.0001).

Conclusion:

CT segmentation provides a quantitative assessment of craniofacial changes following FFS. Significant changes in forehead, chin, and gonial angle parameters were observed. These findings provide a comprehensive quantitative description of skeletal changes following FFS and define postoperative morphometric patterns across key facial regions.