The Relationship between Age and Facial Asymmetry.

Abstract

Facial symmetry is a fundamental goal of plastic surgery, yet some asymmetry is inherent in any face. Three-dimensional photogrammetry allows for rapid, reproducible, and quantitative facial measurements. With this tool, the authors investigated the relationship between age and facial symmetry. The authors imaged normal subjects using three-dimensional photogrammetry. Facial symmetry was calculated by identifying the plane of maximum symmetry and the root-mean-square deviation. Regression analysis was used to assess the relationship between age and symmetry. Subgroup analyses were performed among facial thirds. The authors imaged 191 volunteers with an average age of 26.7 ± 22.2 years (range, 0.3 to 88 years). Root-mean-square deviation of facial symmetry clustered between 0.4 and 1.3 mm (mean, 0.8 ± 0.2 mm). The authors found a significant positive correlation between increasing age and asymmetry (p < 0.001; r = 0.66). The upper, middle, and lower facial third's average root-mean-square deviations were 0.5 ± 0.2 mm (range, 0.2 to 1.2 mm), 0.6 ± 0.2 mm (range, 0.2 to 1.4 mm), and 0.6 ± 0.2 mm (range, 0.2 to 1.2 mm), respectively. Asymmetry also increased with age across all facial thirds (p < 0.001). Facial asymmetry increases with age in each facial third, with a greater asymmetry and increase in asymmetry in the lower two-thirds. Contributing factors may include asymmetric skeletal remodeling along with differential deflation and descent of the soft tissues. The observed correlation between increasing facial asymmetry and age may be a useful guide in plastic surgery to produce age-matched features.