title: Sexual dimorphism of facial appearance in ageing human adults: A cross-sectional study.
abstract: In the forensic sciences, knowledge of facial ageing is very important in searching for both dead and living individuals. Ageing estimations typically model the biological profile, which can be compared to missing persons. The main goals of this current study were to construct ageing trajectories for adult human faces of both sexes and evaluate sexual dimorphism in relation to static allometry. Our study was based on the analysis of three-dimensional facial surface models of 194 individuals 20-80 years of age. The evaluation consisted of a dense correspondence analysis of facial scans and multivariate statistics. It was shown that both age and sex have a significant influence on facial form and shape. Male features included a longer face, with more protruded foreheads, eyebrow ridges and nose, including the region under the upper lip and mandible region, but more retruded cheeks compared to females. Ageing in both sexes shared common traits, such as more pronounced roundness of the face (rectangular in males), decreased facial convexity, increased visibility of skin folds and wrinkles connected with the loss of skin elasticity, and soft tissue stretching, especially in the orbital area and lower face; however, male faces exhibited more intense ageing changes. The above-mentioned sexual dimorphic traits tended to diminish in the elderly age category, though overall sexual dimorphism was heightened with age. The static allometric relationships between size and form or shape were similar in both sexes, except that the larger faces of elderly males displayed more intensive ageing changes.
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic. Electronic address: mima.mydlova@gmail.com.
authors.forename: Miriama
authors.initials: M
authors.lastname: Mydlová
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic; Department of Software and Computer Science, Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic.
authors.forename: Ján
authors.initials: J
authors.lastname: Dupej
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Koudelová
authors.affiliation: Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Velemínská
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005145:Face / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D012727:Sex Characteristics; D055815:Young Adult
keywords: Ageing trajectories; Forensic Anthropology Population Data; Geometric morphometrics; Sexual dimorphism; Static allometry