OBJECTIVES: To evaluate sexual dimorphism of facial form and shape and to describe differences between the average female and male face from 12 to 15 years. SETTING AND SAMPLE POPULATION: Overall 120 facial scans from healthy Caucasian children (17 boys, 13 girls) were longitudinally evaluated over a 4-year period between the ages of 12 and 15 years. MATERIALS AND METHODS: Facial surface scans were obtained using a three-dimensional optical scanner Vectra-3D. Variation in facial shape and form was evaluated using geometric morphometric and statistical methods (DCA, PCA and permutation test). Average faces were superimposed, and the changes were evaluated using colour-coded maps. RESULTS: There were no significant sex differences (p > 0.05) in shape in any age category and no differences in form in the 12- and 13-year-olds, as the female faces were within the area of male variability. From the age of 14, a slight separation occurred, which was statistically confirmed. The differences were mainly associated with size. Generally boys had more prominent eyebrow ridges, more deeply set eyes, a flatter cheek area, and a more prominent nose and chin area. CONCLUSION: The development of facial sexual dimorphism during pubertal growth is connected with ontogenetic allometry.

Department of Anthropology and Human Genetics Faculty of Science Charles University Prague Prague Czech Republic

Department of Anthropology and Human Genetics Faculty of Science Charles University Prague Prague Czech Republic Department of Software and Computer Science Faculty of Mathematics and Physics Charles University Prague Prague Czech Republic

Department of Anthropology and Human Genetics Faculty of Science Charles University Prague Prague Czech Republic Laboratoire d'Anthropologie des Populations du Passé et UMR 5809 du CNRS PACEA Université Bordeaux 1 Talence France