Correction: The effect of sex and age on facial shape directional asymmetry in adults: A 3D landmarks-based method study.

[This corrects the article DOI: 10.1371/journal.pone.0288702.].

Palatal surface development from 6 years of age to early adulthood: data modelling using 3D geometric morphometrics.

OBJECTIVES: The study followed the modelling of postnatal growth of a healthy palate of the Central European (Czech) population sample based on transverse data on sex and age from 6 to 19 years. MATERIALS AND METHODS: Digitised 3D models of 212 healthy palatal surfaces were evaluated using 3D geometric morphometrics and superimpositions. The individuals were grouped based on age (preschool, younger and older school age, younger and older adolescents, young adults) and sex (♂ n = 101, ♀ n = 111). RESULTS: Female palatal development was non-linear and was interrupted between the 10-12 years and then proceeded intensively until the age of 15 when it ceased. In contrast, male-modelled growth was consistent throughout the follow-up and continued linearly until at least 19 years of age. The palate did not widen further with increasing age, and primarily palatal vaulting and heightening were found. The characteristics and distribution of areas with extensive modelled growth changes were comparable in females and males, as confirmed by the location of principal components (PC1 and PC2) within modal space and growth trajectories. The extent of sexual dimorphism increased from 15 years of age due to pubertal spurt combined with earlier completion of palatal development in females. CONCLUSIONS: The study showed modelled healthy palatal development from 6 years of age to early adulthood, which might be utilised as reference standards for the Central European population sample. CLINICAL RELEVANCE: The comparison of normal reference subjects with patients with cranio-maxillo-facial dysmorphologies represents the first step in diagnosing and establishing effective therapy.

Three-dimensional analysis of modeled facial aging and sexual dimorphism from juvenile to elderly age.

A detailed understanding of craniofacial ontogenetic development is important in a variety of scientific disciplines dealing with facial reconstruction, forensic identification, ageing prediction, and monitoring of pathological growth, including the effect of therapy. The main goals of this study were (1) the construction of the facial aging model using local polynomial regression fitting separately for both sexes, (2) evaluation of the aging effect not only on facial form as a whole but also on dimensions important for clinical practice, and (3) monitoring of the development of shape facial sexual dimorphism. Our study was based on the form and shape analysis of three-dimensional facial surface models of 456 individuals aged 14-83 years. The facial models were obtained using a structured light-based optical scanner and divided (for some analyses) into four age categories (juveniles, young adults, middle adults, and elderly adults). The methodology was based on geometric and classic morphometrics including multivariate statistics. Aging in both sexes shared common traits such as more pronounced facial roundness reducing facial convexity, sagging soft tissue, smaller visible areas of the eyes, greater nose, and thinner lips. In contrast to female faces, male faces increase in size until almost 30 years of age. After the age of 70, male facial size not only stagnates, like in females, but actually decreases slightly. Sexual dimorphic traits tended to diminish in the frontal and orbitonasal areas and increase in the gonial area.