Morphology of facial aging: a shape-based quantification

Facial aging is a natural reflection of the passage of time, shaped by genetics, environment, and lifestyle. Before attempting to adjust the aging face, the plastic surgeon needs to understand normal facial aging in terms of shape. The aim of our study was to analyze the facial profile of the Romanian population and to characterize facial shape age-related changes using geometric morphometrics. The study group comprised 140 participants (70 males, 70 females) aged 10-51 years, categorized into five age groups: 10-14, 15-20, 21-30, 31-40, and >40 years. Frontal photographs of all participants were taken using a digital camera. Twenty-four paired and unpaired landmarks were marked on the face of each individual using tpsDIG2w64 program. Digitized landmarks were superimposed, aligned and averaged based on least-squares Procrustes analysis. For each age group, a consensus configuration of landmarks was generated for shape comparison. Thin-plate splines (TPSs) and relative warps (RWs) were used to explore and quantify facial aging from one age group to another. In case of the male face, maximum variability was registered for tragus, gonion, gnathion, and moderate variability for trichion, glabella, nasion, subnasale, orbitale superius, and alare. The first RW explained 51.97% of total shape variation and primarily represented vertical transformations, while the second RW (horizontal changes) was responsible for 12.07% of shape variation. While males showed initial growth of the lower face, females demonstrate earlier development in the upper facial region. Pair landmarks were more prone to changes in female and, contrary to men, facial aging was almost equally distributed on the vertical and horizontal axes, the first RW being responsible for 38.07% and the second RW for 27.16% of total shape change. In conclusion, the aging adult human face undergoes a gender-specific transformation in shape and form.