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.

Simulation of facial growth based on longitudinal data: Age progression and age regression between 7 and 17 years of age using 3D surface data.

Modelling of the development of facial morphology during childhood and adolescence is highly useful in forensic and biomedical practice. However, most studies in this area fail to capture the essence of the face as a three-dimensional structure. The main aims of our present study were (1) to construct ageing trajectories for the female and male face between 7 and 17 years of age and (2) to propose a three-dimensional age progression (age -regression) system focused on real growth-related facial changes. Our approach was based on an assessment of a total of 522 three-dimensional (3D) facial scans of Czech children (39 boys, 48 girls) that were longitudinally studied between the ages of 7 to 12 and 12 to 17 years. Facial surface scans were obtained using a Vectra-3D scanner and evaluated using geometric morphometric methods (CPD-DCA, PCA, Hotelling's T2 tests). We observed very similar growth rates between 7 and 10 years in both sexes, followed by an increase in growth velocity in both sexes, with maxima between 11 and 12 years in girls and 11 to 13 years in boys, which are connected with the different timing of the onset of puberty. Based on these partly different ageing trajectories for girls and boys, we simulated the effects of age progression (age regression) on facial scans. In girls, the mean error was 1.81 mm at 12 years and 1.7 mm at 17 years. In boys, the prediction system was slightly less successful: 2.0 mm at 12 years and 1.94 mm at 17 years. The areas with the greatest deviations between predicted and real facial morphology were not important for facial recognition. Changes of body mass index percentiles in children throughout the observation period had no significant influence on the accuracy of the age progression models for both sexes.

Sexual dimorphism of facial appearance in ageing human adults: A cross-sectional study.

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.

Modelling of facial growth in Czech children based on longitudinal data: Age progression from 12 to 15 years using 3D surface models.

Dealing with the increasing number of long-term missing children and juveniles requires more precise and objective age progression techniques for the prediction of their current appearance. Our contribution includes detailed and real facial growth information used for modelling age progression during adolescence. This study was based on an evaluation of the overall 180 three-dimensional (3D) facial scans of Czech children (23 boys, 22 girls), which were longitudinally studied from 12 to 15 years of age and thus revealed the real growth-related changes. The boys underwent more marked changes compared with the girls, especially in the regions of the eyebrow ridges, nose and chin. Using modern geometric morphometric methods, together with their applications, we modelled the ageing and allometric trajectories for both sexes and simulated the age-progressed effects on facial scans. The facial parts that are important for facial recognition (eyes, nose, mouth and chin) all deviated less than 0.75mm, whereas the areas with the largest deviations were situated on the marginal parts of the face. The mean error between the predicted and real facial morphology obtained by modelling the children from 12 to 15 years of age was 1.92mm in girls and 1.86mm in boys. This study is beneficial for forensic artists as it reduces the subjectivity of age progression methods.

Concave impressio ligamenti costoclavicularis ("rhomboid fossa") and its prevalence and relevance to clinical practice.

PURPOSE: The incidence of fossa rhomboidea (RF) and its relevance to clinical practice were retrospectively studied in 1,017 cases of patients who endured clavicle fractures. The aim of the study was to determine the frequency of different types of insertion areas of costoclavicular ligament (LCC) in our group, as well as gender distribution. Furthermore, we wanted to investigate whether the RF represents a weakened part of clavicle where the fracture occurred. Several of our findings in our control group were quite interesting and worth mentioning. MATERIALS AND METHODS: 1,017 roentgenograms were analyzed from 1,027 clavicle fractures of patients from 2 to 90 years of age who were treated between 2007 and 2011. RESULTS: Using the Allman classification system, 79% of the examined clavicle fractures were identified as type 1, 18.4% as type 2, and 2.6% as type 3. Statistical analysis did not demonstrate a difference in fractures of the clavicle between the right and the left side (47, 53%, respectively; p = 0.0570). There was a statistically significant difference in the incidence of fractures between the genders (males 71%, females 29 %; p < 0.0001). The results for the insertion attachment area were as follows for the given percent of cases: flat (75.2%); concave (21.1%); convex (3.7%). Those 21.1% of concave insertions represent RF. 5.3% of RF cases were between 2 to 10 mm in depth. One of the patients with RF had a deepend insertion of the LCC on the superior surface of the first rib analogous to RF. The bilateral RF was asymmetrical in its appearance. One of the patients suffered from LCC enthesopathy. The difference of the distribution of RF throughout the genders was 10.5% in females and 89.5% in males, marking a difference that is statistically significant (p < 0.0001). Only in 0.3%, the fracture line occurred in RF, which did not prove the RF to be a weakened point of the fracture (p < 0.0001). CONCLUSIONS: RF represents a variety of LCC insertion that is predominantly found in male patients, which can be used in the determination of gender in forensic analysis. RF is not a weak point for fracture formation. Enthesopathy of the LCC together with RF can lead to suspicion concerning the osteolytic process. Biopsy of RF should be avoided. Insertion of LCC similar to RF can be exceptionally found on the first rib.