Rostovtseva Victoria Viktorovna

Introduction. In this article, we have compared frontal facial shapes (based on photo portraits) which were captured in two head positions: Natural position (NP) and Frankfurt horizontal (FH).

Materials and methods. In both cases facial shape was analyzed on sex differences and association with direct measurements of body parameters: height, BMI, fat, muscle and bone mass, digit ratio (R2D:4D). The analysis was performed using geometric morphometry methods. The study participants were representatives of the non-European population, Buryats, 86 men and 69 women aged 20 years (20± 2 g).

Results. The results showed that (a) head position had a significant impact on the 2D projection of the frontal facial shape, particularly in men; (b) compared to the Natural position, the Frankfurt horizontal position exhibited more pronounced sex differences in facial shape; (c) we observed associations between facial shape and height, BMI, fat, and muscle mass in both men and women in both positions, but these associations were more pronounced in the Frankfurt horizontal. We did not find an association between male facial shape and R2D:4D in the NP position, but we observed it in FH. In women, we did not observe a similar relationship in both positions.

Discussion. Our research revealed an important methodological problem: the head position can significantly affect qualitative conclusions about frontal facial shape, especially in non-European populations. In our study, we found a statistical relationship with most body parameters in both cases, FH and NP. However, the relationship was stronger in the FH position. When working with independent parameters that have a generally not very pronounced effect on the facial shape, head position differences can lead to a decrease or even a lack of an association when using a natural position (as in the case of R2D:4D).

Conclusion. The obtained results are important for the development of an optimal photography methodology, taking into account the currently accumulated controversial results. Current findings allow us to resolve a number of contradictions related to the zero results observed in modern literature data.

Introduction. The problem of human adaptation to modern realities, including living in cities, changing the traditional diet, and significantly reducing physical stress on the body in everyday life is becoming increasingly relevant all over the world. In this vein, experts from various fields of science pay attention to the study of general secular trends and a more detailed analysis of individual components of this phenomenon, including body composition and other somatic characteristics of specific social and/or gender and age groups of the population. Of particular interest are data on urban populations that have recently migrated from rural areas, against the background of significant socio-economic transformations in the countries of the Global South, as well as a comparison of data from different regions of the world to identify common and population-specific indicators of adaptation.

Materials and methods. The paper presents data on students from three populations (684 individuals, 343 of them men and 341 women): Tanzanian (natives of the Bantu peoples from Dodoma), Russian (residents of Tula) and Buryat (residents of Ulan-Ude). The age ranges from 17 to 30 years, the average age was 21.28±2.75 y. A number of anthropometric characteristics and body composition were measured.

Results. Our data indicate the presence of sexual dimorphism in each of the studied populations according to the complex of morphological characteristics and body composition. It is noteworthy that Russian students (Caucasians) had more pronounced sexual dimorphism compared to Tanzanians (Negroids) and Buryats (Mongoloids).

Conclusion. Summing up, data on three populations representing samples of young people who are similar in social status and level of education, but differ in their racial and ethnic origin, as well as the environmental characteristics of the regions of residence, indicate the presence of distinct differences between the sexes in body size and its component composition. These differences were unidirectional in the three samples studied, and may reflect the generalized outcome of natural and sexual selection for Homo sapiens. © 2024. This work is licensed under a CC BY 4.0 license

Introduction. The study of emotional facial expressions is currently gaining momentum, attracting researchers from diverse scientific disciplines. We suppose that this surge in interest can be attributed, in part, to the rapid advancement of digital technologies, particularly artificial neural networks, which are increasingly capable of recognizing and encoding facial expressions. The power of these technologies to analyze faces and emotional states is widely discussed in the media and popular culture, prompting scientists to approach the topic with both responsibility and maximum caution in judgements.

Results. Important to mention immediately, that in the modern literature on the anatomy of facial expression, there is no consensus on the number and composition of muscles involved in the expression of emotions on the human face. Different authors indicate a different number of muscles involved in emotional facial expressions. Such discrepancies may cause significant confusion, especially for researchers who are not specialists in human anatomy. This article presents an analytical review based on anatomical sources and the Facial Action Coding System (FACS), a leading anatomically validated technique for recognizing and classifying facial expressions. Alongside the anatomy of the muscular system, we explore the characteristics of the related neural structures. To provide readers with a comprehensive understanding of facial communication, we delve into the history of its study and present an evolutionary journey tracing the development of the human face, the emergence, and evolution of facial expressions in phylogeny.

Conclusion. Facial expressions of emotion are the result of a long evolutionary process, closely interrelated with the development of the nervous system and social organization. Based on the most comprehensive data, the muscular system underlying human emotional expressions is more complex than typically suggested in anatomical classifications. Overall, it comprises 26 paired and one single muscle, many of which are further subdivided into smaller parts with distinct expressive functions. We believe that this article will help to systematize modern data on the anatomy of human facial expressions. © 2025. This work is licensed under a CC BY 4.0 license