Racial and Regional Differences of the Cheek for Facial Feminization: A Systematic Review

Reports of sexual dimorphism of malar dimensions across race and region are limited. Establishing optimal quantitative norms for the midface divided between the sexes aids facial feminization surgical planning, especially when stratified according to race and region of origin. To provide malar dimension measures specific to sex, race, and region to aid facial feminization preoperative planning, a systematic review and meta-analysis of midface measurements, including bizygomatic width (BW) and soft-tissue thickness overlying the zygoma, was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We included 24 studies, including 11,122 patients. A total of 5729 patients (51.5%) were female. Sexual dimorphism of BW was observed across racial groups and regions, with males consistently exhibiting significantly larger BWs than females. Multivariate regression models accounting for both race and region, rather than race or region solely, predicted BW variability the best among male [race and region explained 71% of BW variance (R2=0.71)] and female [race and region explained 82% of BW variance (R2=0.82)] patients. Soft tissue thickness overlying the zygoma data was limited. Accounting for race and region when planning malar facial feminization surgery could optimize outcomes while preserving ethnic characteristics. Our results should be interpreted in the context of facial height sexual dimorphism; ethnic groups with larger differences in facial height may require less dramatic BW adjustments to conserve race-specific facial proportions. Further research on overall facial anatomy will help contextualize the surgical implications of our BW results.