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Kleisner K, Pokorný Š, Černý V. Sexually dimorphic traits are associated with subsistence strategy in African faces from the Sahel/Savannah belt. Am J Hum Biol 2024; 36:e24008. [PMID: 37897188 DOI: 10.1002/ajhb.24008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/30/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
OBJECTIVES Previous research revealed that in some African populations, food-production strategies are associated with facial shape. Nomadic pastoralists living in the African Sahel/Savannah belt have a different facial morphology than their sedentary neighbors. We investigated whether the lifestyle associated with a subsistence pattern has an impact on sexual dimorphism in the facial structure. METHODS We employed several methods from geometric morphometrics and demonstrated such effect in four ethnically distinct populations that share the same geographic space. RESULTS We show that the facial traits which correlate with a subsistence strategy are systematically associated with levels of facial sex-typicality. In particular, we found that faces with more pronounced pastoralist features have on average more masculine facial traits and that this effect is more pronounced in men than in women. CONCLUSIONS In general, though, the magnitude of overall facial dimorphism does not differ between pastoralists and farmers. Pastoralists (in contrast to farmers) tend to have a more masculine facial morphology but facial differences between the sexes are in both groups the same.
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Affiliation(s)
- Karel Kleisner
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Šimon Pokorný
- Department of Philosophy and History of Science, Faculty of Science, Charles University, Prague, Czech Republic
| | - Viktor Černý
- Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic
- Archaeogenetics Laboratory, Institute of Archaeology of the Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Gupta S, Fernandes R, Natarajan S, Jose NP, Giri J, Dahal S. Comparative evaluation of arch form among the Nepalese population: A morphological study. J Oral Maxillofac Pathol 2024; 28:111-118. [PMID: 38800435 PMCID: PMC11126270 DOI: 10.4103/jomfp.jomfp_280_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 09/20/2023] [Accepted: 10/09/2023] [Indexed: 05/29/2024] Open
Abstract
Aims The study aims to identify sexual dimorphic features in the arch patterns based on tooth arrangement patterns and the maxillary and mandibular arches using Euclidean Distance Matrix Analysis (EDMA). Settings and Design A total of 96 Nepalese subjects, aged 18 to 25 were assessed using casts and photographs. Materials and Methods Thirteen landmarks representing the most facial portions of the proximal contact areas on the maxillary and mandibular casts were digitised. Seventy-eight possible, Euclidean distances between the 13 landmarks were calculated using the Analysis ToolPak of Microsoft Excel®. The male-to-female ratios of the corresponding distances were computed and ratios were compared to evaluate the arch form for variation in the genders, among the Nepalese population. Statistical Analysis Used Microsoft Excel Analysis ToolPak and SPSS 20.0 (IBM Chicago) were used to perform EDMA and an independent t-test to compare the significant differences between the two genders. Results The maxillary arch's largest ratio (1.008179001) was discovered near the location of the right and left lateral incisors, indicating that the anterior region may have experienced the greatest change. The posterior-molar region is where the smallest ratio was discovered, suggesting less variation. At the intercanine region, female arches were wider than male ones; however, at the interpremolar and intermolar sections, they were similar in width. Females' maxillary arches were discovered to be bigger antero-posteriorly than those of males. The highest ratio (1.014336113) in the mandibular arch was discovered at the intermolar area, suggesting that males had a larger mandibular posterior arch morphology. At the intercanine area, the breadth of the arch form was greater in males and nearly the same in females at the interpremolar and intermolar regions. Female mandibular arch forms were also discovered to be longer than those of males from the anterior to the posterior. Conclusions The male and female arches in the Nepalese population were inferred to be different in size and shape. With references to the landmarks demonstrating such a shift, the EDMA established objectively the presence of square arch forms in Nepali males and tapering arch forms in Nepalese females.
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Affiliation(s)
- Simran Gupta
- Intern, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Rhea Fernandes
- Intern, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Srikant Natarajan
- Department of Forensic Odontology, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Nidhin P. Jose
- Department of Orthodontics and Dentofacial Orthopaedics, Manipal College of Dental Sciences, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Jamal Giri
- Department of Orthodontics, B.P. Koirala Institute of Health Sciences, Dharan, Nepal, India
| | - Samarika Dahal
- Department of Oral Pathology and Forensic Dentistry, Maharajgunj Medical Campus, Institute of Medicine, Nepal, India
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Matthews HS, Mahdi S, Penington AJ, Marazita ML, Shaffer JR, Walsh S, Shriver MD, Claes P, Weinberg SM. Using data-driven phenotyping to investigate the impact of sex on 3D human facial surface morphology. J Anat 2023. [PMID: 36943032 DOI: 10.1111/joa.13866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
The effects of sex on human facial morphology have been widely documented. Because sexual dimorphism is relevant to a variety of scientific and applied disciplines, it is imperative to have a complete and accurate account of how and where male and female faces differ. We apply a comprehensive facial phenotyping strategy to a large set of existing 3D facial surface images. We investigate facial sexual dimorphism in terms of size, shape, and shape variance. We also assess the ability to correctly assign sex based on shape, both for the whole face and for subregions. We applied a predefined data-driven segmentation to partition the 3D facial surfaces of 2446 adults into 63 hierarchically linked regions, ranging from global (whole face) to highly localized subparts. Each facial region was then analyzed with spatially dense geometric morphometrics. To describe the major modes of shape variation, principal components analysis was applied to the Procrustes aligned 3D points comprising each of the 63 facial regions. Both nonparametric and permutation-based statistics were then used to quantify the facial size and shape differences and visualizations were generated. Males were significantly larger than females for all 63 facial regions. Statistically significant sex differences in shape were also seen in all regions and the effects tended to be more pronounced for the upper lip and forehead, with more subtle changes emerging as the facial regions became more granular. Males also showed greater levels of shape variance, with the largest effect observed for the central forehead. Classification accuracy was highest for the full face (97%), while most facial regions showed an accuracy of 75% or greater. In summary, sex differences in both size and shape were present across every part of the face. By breaking the face into subparts, some shape differences emerged that were not apparent when analyzing the face as a whole. The increase in facial shape variance suggests possible evolutionary origins and may offer insights for understanding congenital facial malformations. Our classification results indicate that a high degree of accuracy is possible with only parts of the face, which may have implications for biometrics applications.
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Affiliation(s)
- Harold S Matthews
- Department of Human Genetics, KU Leuven, 3000, Leuven, Belgium
- Medical Imaging Research Center, UZ Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Soha Mahdi
- Medical Imaging Research Center, UZ Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Anthony J Penington
- Facial Sciences Research Group, Murdoch Children's Research Institute, Parkville, 3052, Australia
- Department of Plastic and Maxillofacial Surgery, Royal Children's Hospital, Melbourne, 3052, Australia
- Department of Pediatrics, University of Melbourne, Melbourne, 3052, Australia
| | - Mary L Marazita
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15219, USA
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, USA
| | - John R Shaffer
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15219, USA
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, USA
| | - Susan Walsh
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, Indiana, 46202, USA
| | - Mark D Shriver
- Department of Anthropology, Pennsylvania State University, State College, Pennsylvania, 16802, USA
| | - Peter Claes
- Department of Human Genetics, KU Leuven, 3000, Leuven, Belgium
- Medical Imaging Research Center, UZ Leuven, Herestraat 49, 3000, Leuven, Belgium
- Facial Sciences Research Group, Murdoch Children's Research Institute, Parkville, 3052, Australia
- Department of Electrical Engineering, ESAT/PSI, KU Leuven, 3000, Leuven, Belgium
| | - Seth M Weinberg
- Center for Craniofacial and Dental Genetics, Department of Oral and Craniofacial Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15219, USA
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, USA
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Yamamoto S, Tanikawa C, Yamashiro T. Morphologic variations in the craniofacial structures in Japanese adults and their relationship with sex differences. Am J Orthod Dentofacial Orthop 2023; 163:e93-e105. [PMID: 36621352 DOI: 10.1016/j.ajodo.2022.07.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 07/01/2022] [Accepted: 07/01/2022] [Indexed: 01/08/2023]
Abstract
INTRODUCTION The morphology of the human face varies broadly, with genetic and environmental factors determining these variations. Examining variations in the 3-dimensional (3D) craniomandibular morphology and identifying related factors (eg, sex differences) are important in orthodontic clinics. This study observed shape variations in the 3D facial morphology of Japanese adults showing skeletal Class 1 malocclusion and examined the association of sexual dimorphism with shape variations. METHODS Sixty cone-beam computed tomography images of Japanese adults (30 males and 30 females) with skeletal Class I malocclusion were employed. In each cone-beam computed tomography image, wire mesh fitting was conducted as previously described. A principal component (PC) analysis after Procrustes registration and the PC clustering method was conducted to observe the shape variations. A PC regression analysis was conducted to determine the sexual morphologic characteristics. RESULTS Nine PCs depicting 62% of the morphology were determined. Four typical phenotypes were found, mainly related to mandibular protrusion (PC1) and the vertical divergence of the face (PC2). PCs related to sex determination were PC3 (robustness of the mandibular angle in males), PC5 (greater size and shape of the coronoid and mastoid processes in males), and PC7 (greater maxillary width in males), accounting for 16% of total variations. CONCLUSIONS The major shape variations in skeletal Class 1 subjects were related to nonsexual dimorphic characteristics (ie, mandibular protrusion and facial divergence). Sexual dimorphic characteristics were evaluated in detail and accounted for 16% of total morphologic variations.
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Affiliation(s)
- Sayuri Yamamoto
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
| | - Chihiro Tanikawa
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan.
| | - Takashi Yamashiro
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
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Rostovtseva VV, Butovskaya ML, Mezentseva AA, Weissing FJ. Effects of sex and sex-related facial traits on trust and trustworthiness: An experimental study. Front Psychol 2023; 13:925601. [PMID: 36687832 PMCID: PMC9849902 DOI: 10.3389/fpsyg.2022.925601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 12/08/2022] [Indexed: 01/07/2023] Open
Abstract
The ability to trust others, including strangers, is a prerequisite for human cooperation. Economically it is not rational to trust strangers, as trust can be easily exploited. Still, generally, the level of trust toward strangers is relatively high. Trust is closely related to trustworthiness: when trusting others, one expects them to reciprocate. Some individuals elicit more trust than others. Apparently, humans use subtle cues for judging the trustworthiness of their interaction partners. Here, we report on an experiment that investigates trust and trustworthiness in a population of 176 mainly Dutch students. The aims of our study were: (1) to investigate how the sex of interaction partners and their facial appearance (femininity/masculinity) affect the degree of trust and trustworthiness, compared to fully anonymous conditions; (2) to test whether individuals who elicit trust in their interaction partners are trustworthy themselves. Each subject of our experiment played five one-shot Trust Games: one with an anonymous interaction partner, and four "personalized" games after seeing a 20 s silent video of their interaction partner (twice same-sex, and twice opposite-sex). The degree of facial sexual dimorphism was investigated with geometric morphometrics based on full-face photographs. Our results revealed that, despite the already high level of trust in the anonymous setting, the personalization of interactions had a clear effect on behavior. Females elicited more trust in partners of both sexes. Interestingly, females with more feminine faces elicited less trust in both male and female partners, while males with more masculine facial shape were more trusted by females, but less trusted by males. Neither sex nor facial femininity/masculinity predicted trustworthiness. Our results demonstrate that (1) sex and sex-related facial traits of interaction partners have a clear effect on eliciting trust in strangers. However, (2) these cues are not reliable predictors of actual trustworthiness.
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Affiliation(s)
- Victoria V. Rostovtseva
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands,Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russia,*Correspondence: Victoria V. Rostovtseva,
| | - Marina L. Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russia
| | - Anna A. Mezentseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russia
| | - Franz J. Weissing
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
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González-Álvarez J, Sos-Peña R. Sex perception from facial structure: Categorization with and without skin texture and color. Vision Res 2022; 201:108127. [PMID: 36194981 DOI: 10.1016/j.visres.2022.108127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 04/26/2022] [Accepted: 07/17/2022] [Indexed: 11/06/2022]
Abstract
Sex identification of faces without any cultural or conventional sex cue is primarily based on two independent components: a) shape or facial structure, and b) surface reflectance (skin texture and color). The present work studied the relative contribution of each component by means of two experiments based on 3D face models created with different degrees of masculinity-femininity within a sex continuum. The first experiment utilized totally artificial faces created ex novo by computer. The second employed face models created from photographs of real people. The results of both experiments were consistent. As expected, when both components were present in a face, sex was correctly classified in almost all the cases. More interestingly, the contribution of the "pure" facial structure to the sex perception (with no surface reflectance) was about 80%, whereas 20% of the total information was provided by the surface reflectance. Furthermore, examination of the psychometric curves suggests that the information provided by surface reflectance contributes to a categorical perception of facial sex, since when it is removed the sex is perceived in a more continuous / less categorical way. On the other hand, our stimuli presented a certain "male" bias, repeatedly found in the literature on facial sex perception.
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Affiliation(s)
- Julio González-Álvarez
- Department of Basic and Clinical Psychology and Psychobiology, University Jaume I, Castellón, Spain.
| | - Rosa Sos-Peña
- Department of Basic and Clinical Psychology and Psychobiology, University Jaume I, Castellón, Spain
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Tanikawa C, Kurata M, Tanizaki N, Takeuchi M, Zere E, Fukuo K, Takada K. Influence of the nutritional status on facial morphology in young Japanese women. Sci Rep 2022; 12:18557. [PMID: 36329131 PMCID: PMC9633753 DOI: 10.1038/s41598-022-21919-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 10/05/2022] [Indexed: 11/06/2022] Open
Abstract
Evidence regarding the possible influence of nutritional status on the facial morphology has thus far been insufficient. We examined whether or not the physical body compositions and dietary behaviors were correlated with any morphological characteristics of the face. One hundred and fifteen young Japanese women participated. Variables representing the dietary behaviors were extracted from self-reported survey data, and corresponding three-dimensional (3D) facial images and body compositions were examined. Multivariate analyses identified significant relationships between the nutritional status and facial topography (p < 0.05). The clustering method revealed the existence of three dietary condition patterns ("balanced diet", "high-calorie-diet" with obesity tendency, and "imbalanced low-calorie-diet" with sarcopenic obesity tendency). Among these three patterns, a round face (increased facial width; analysis of variance [ANOVA], p < 0.05) was observed in the high-calorie-diet pattern, while the imbalanced low-calorie-diet pattern showed a more masculine face (increased face height, decreased eye height, increased non-allometric sexual shape differences; ANOVA, p < 0.05), thus suggesting the possibility of sex-hormonal influences. In summary, the body composition and dietary behaviors were found to influence the facial morphology, and potential biological influences were discussed.
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Affiliation(s)
- Chihiro Tanikawa
- grid.136593.b0000 0004 0373 3971Department of Orthodontics and Dentofacial Orthopedics, Osaka University Dental Hospital, Suita, Osaka Japan
| | - Miki Kurata
- grid.260338.c0000 0004 0372 6210Department of Food Sciences and Nutrition, School of Human Environmental Sciences, Mukogawa Women’s University, Nishinomiya, Hyogo Japan
| | - Noriko Tanizaki
- grid.260338.c0000 0004 0372 6210Department of Food Sciences and Nutrition, School of Human Environmental Sciences, Mukogawa Women’s University, Nishinomiya, Hyogo Japan
| | - Mika Takeuchi
- grid.260338.c0000 0004 0372 6210Department of Food Sciences and Nutrition, School of Human Environmental Sciences, Mukogawa Women’s University, Nishinomiya, Hyogo Japan
| | - Edlira Zere
- grid.136593.b0000 0004 0373 3971Department of Orthodontics and Dentofacial Orthopedics, Osaka University Dental Hospital, Suita, Osaka Japan
| | - Keisuke Fukuo
- grid.260338.c0000 0004 0372 6210Department of Food Sciences and Nutrition, School of Human Environmental Sciences, Mukogawa Women’s University, Nishinomiya, Hyogo Japan
| | - Kenji Takada
- grid.136593.b0000 0004 0373 3971Center for Advanced Medical Engineering and Informatics, Osaka University, Suita, Osaka Japan
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de Oliveira I, Pinheiro R, Freitas B, Reher P, Rodrigues V. Relationship between craniofacial and dental arch morphology with pharyngeal airway space in adolescents. J Orofac Orthop 2022; 84:93-103. [PMID: 35608631 DOI: 10.1007/s00056-022-00403-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 02/25/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE The aim of the study was to investigate a possible relationship between pharyngeal airway space, craniofacial variables, and dental arch form in adolescents grouped by sex. METHODS This cross-sectional study included 108 adolescents aged between 12 and 17 years. Lateral cephalometric radiographs were used to analyze sagittal craniofacial variables and the pharyngeal airway space. For evaluation of the dental arch form, we used plaster models. Statistical analysis included Student's t‑test and Pearson's correlation coefficient (r). RESULTS Maxillary length was directly proportional to upper nasopharyngeal airway dimensions in males (r = 0.312, p = 0.021) and females (r = 0.310, p = 0.022). In the female group, upper oropharyngeal measurements showed an inverse correlation with a labial inclination of the upper incisors (r = -0.415, p = 0.001), protrusion of the upper incisors (r = -0.364, p = 0.006), and soft palate thickness (r = -0.27, p = 0.043). In the male group, upper nasopharynx measurements showed an inverse correlation with soft palate thickness (r = -0.277, p = 0.042). The upper arch form appeared to be related to oropharyngeal measurements in females, while the lower arch form was related to oropharyngeal dimensions in males. CONCLUSION The findings suggest that there are sex-dependent correlations of the nasopharyngeal and oropharyngeal airway space with the sagittal craniofacial morphology and the transversal dental arch form.
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Affiliation(s)
| | - Raysa Pinheiro
- School of Dentistry, Federal University of Maranhão, São Luís, Brazil
| | - Benedito Freitas
- School of Dentistry, Federal University of Maranhão, São Luís, Brazil
| | - Peter Reher
- School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia
| | - Vandilson Rodrigues
- School of Dentistry, Federal University of Maranhão, São Luís, Brazil. .,Department of Morphology, Federal University of Maranhão, São Luís, Brazil.
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Butovskaya ML, Rostovtseva VV, Mezentseva AA. Facial and body sexual dimorphism are not interconnected in the Maasai. J Physiol Anthropol 2022; 41:3. [PMID: 34996526 PMCID: PMC8740871 DOI: 10.1186/s40101-021-00276-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/10/2021] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND In this paper, we investigate facial sexual dimorphism and its' association with body dimorphism in Maasai, the traditional seminomadic population of Tanzania. We discuss findings on other human populations and possible factors affecting the developmental processes in Maasai. METHODS Full-face anthropological photographs were obtained from 305 Maasai (185 men, 120 women) aged 17-90 years. Facial shape was assessed combining geometric morphometrics and classical facial indices. Body parameters were measured directly using precise anthropological instruments. RESULTS Sexual dimorphism in Maasai faces was low, sex explained 1.8% of the total shape variance. However, male faces were relatively narrower and vertically prolonged, with slightly wider noses, narrower-set and lower eyebrows, wider mouths, and higher forehead hairline. The most sexually dimorphic regions of the face were the lower jaw and the nose. Facial width-to-height ratio (fWHR), measured in six known variants, revealed no significant sexual dimorphism. The allometric effects on facial traits were mostly related to the face growth, rather than the growth of the whole body (body height). Significant body dimorphism was demonstrated, men being significantly higher, with larger wrist diameter and hand grip strength, and women having higher BMI, hips circumferences, upper arm circumferences, triceps skinfolds. Facial and body sexual dimorphisms were not associated. CONCLUSIONS Facial sex differences in Maasai are very low, while on the contrary, the body sexual dimorphism is high. There were practically no associations between facial and body measures. These findings are interpreted in the light of trade-offs between environmental, cultural, and sexual selection pressures.
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Affiliation(s)
- Marina L Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, 119334, Russia.
- The National Research University Higher School of Economics, Moscow, 101000, Russia.
- Russian State University for the Humanities, Moscow, 125047, Russia.
| | - Victoria V Rostovtseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Anna A Mezentseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, 119334, Russia
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Maeda J, Tanikawa C, Nagata N, Lim J, Kreiborg S, Murakami S, Yamashiro T. Comparison of 3-D mandibular surfaces generated by MRI and CT. Orthod Craniofac Res 2021; 25:351-358. [PMID: 34606173 DOI: 10.1111/ocr.12540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/18/2021] [Accepted: 08/27/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the errors of three-dimensional mandibular surfaces generated using magnetic resonance imaging (MRI) when computed tomography (CT) was set as the gold standard. SETTINGS AND SAMPLE POPULATION Seven patients with orthognathic deformities who had undergone CT and MRI scans were included in the study. MATERIALS AND METHODS Mandibular surfaces were generated on each CT and MR image by the surface-rendering method. Intra-individual reliability between CT and MRI was statistically tested by the confidence limits of agreement (LOA) for systematic error, 95% confidence interval minimal detectable change (MDC95 ) for random error and intra-class correlation coefficient (ICC). RESULTS The average total error was 1.6 mm. The greatest MDC95 was observed in the coronoid region in all directions. The other regions showed MDC95 values of < 1.8 mm (transvers direction), 3.5 mm (vertical direction) and 1.7 mm (antero-posterior direction). ICCs showed 'almost perfect' agreement with respect to all regions. CONCLUSION Random errors were quantified for 3-D rendering of the mandible from MRI data. Although the coronoid region showed the greatest errors, the other regions of the mandibular surfaces generated using MRI were able to be evaluated.
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Affiliation(s)
- Jun Maeda
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Japan
| | - Chihiro Tanikawa
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Japan
| | - Namiki Nagata
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Japan
| | - Jaeyeon Lim
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Japan
| | - Sven Kreiborg
- Section for Paediatric Dentistry, School of Dentistry, University of Copenhagen, Copenhagen, Denmark
| | - Shumei Murakami
- Department of Oral and Maxillofacial Radiology, Graduate School of Dentistry, Osaka University, Suita, Japan
| | - Takashi Yamashiro
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka University, Suita, Japan
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11
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Population affinity and variation of sexual dimorphism in three-dimensional facial forms: comparisons between Turkish and Japanese populations. Sci Rep 2021; 11:16634. [PMID: 34404851 PMCID: PMC8371176 DOI: 10.1038/s41598-021-96029-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/28/2021] [Indexed: 11/22/2022] Open
Abstract
Examining the extent to which sex differences in three-dimensional (3D) facial soft tissue configurations are similar across diverse populations could suggest the source of the indirect evolutionary benefits of facial sexual dimorphism traits. To explore this idea, we selected two geographically distinct populations. Three-dimensional model faces were derived from 272 Turkish and Japanese men and women; their facial morphologies were evaluated using landmark and surface-based analyses. We found four common facial features related to sexual dimorphism. Both Turkish and Japanese females had a shorter lower face height, a flatter forehead, greater sagittal cheek protrusion in the infraorbital region but less prominence of the cheek in the parotid-masseteric region, and an antero-posteriorly smaller nose when compared with their male counterparts. The results indicated the possible phylogenetic contribution of the masticatory organ function and morphogenesis on sexual dimorphism of the human face in addition to previously reported biological and psychological characteristics, including sexual maturity, reproductive potential, mating success, general health, immune response, age, and personality.
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12
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Development of novel artificial intelligence systems to predict facial morphology after orthognathic surgery and orthodontic treatment in Japanese patients. Sci Rep 2021; 11:15853. [PMID: 34349151 PMCID: PMC8339122 DOI: 10.1038/s41598-021-95002-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 07/13/2021] [Indexed: 12/15/2022] Open
Abstract
From a socio-psychological standpoint, improving the morphology of the facial soft-tissues is regarded as an important therapeutic goal in modern orthodontic treatment. Currently, many of the algorithms used in commercially available software programs that are said to provide the function of performing profile prediction are based on the false assumption that the amount of movement of hard-tissue and soft-tissue has a proportional relationship. The specification of the proportionality constant value depends on the operator, and there is little evidence to support the validity of the prediction result. Thus, the present study attempted to develop artificial intelligence (AI) systems that predict the three-dimensional (3-D) facial morphology after orthognathic surgery and orthodontic treatment based on the results of previous treatment. This was a retrospective study in a secondary adult care setting. A total of 137 patients who underwent orthognathic surgery (n = 72) and orthodontic treatment with four premolar extraction (n = 65) were enrolled. Lateral cephalograms and 3-D facial images were obtained before and after treatment. We have developed two AI systems to predict facial morphology after orthognathic surgery (System S) and orthodontic treatment (System E) using landmark-based geometric morphometric methods together with deep learning methods; where cephalometric changes during treatment and the coordinate values of the faces before treatment were employed as predictive variables. Eleven-fold cross-validation showed that the average system errors were 0.94 mm and 0.69 mm for systems S and E, respectively. The total success rates, when success was defined by a system error of < 1 mm, were 54% and 98% for systems S and E, respectively. The total success rates when success was defined by a system error of < 2 mm were both 100%. AI systems to predict facial morphology after treatment were therefore confirmed to be clinically acceptable.
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Lee D, Tanikawa C, Yamashiro T. Impairment in facial expression generation in patients with repaired unilateral cleft lip: Effects of the physical properties of facial soft tissues. PLoS One 2021; 16:e0249961. [PMID: 33886591 PMCID: PMC8061991 DOI: 10.1371/journal.pone.0249961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/26/2021] [Indexed: 11/18/2022] Open
Abstract
Patients with repaired unilateral cleft lip with palate (UCLP) often show dysmorphology and distorted facial motion clinically, which can cause psychological issues. However, no report has clarified the details concerning distorted facial motion and the corresponding possible causative factors. In this study, we hypothesized that the physical properties of the scar and surrounding facial soft tissue might affect facial displacement while smiling in patients with UCLP (Cleft group). We thus examined the three-dimensional (3D) facial displacement while smiling in the Cleft and Control groups in order to determine whether or not the physical properties of facial soft tissues differ between the Cleft and Control groups and to examine the relationship between the physical properties of facial soft tissues on 3D facial displacement while smiling. Three-dimensional images at rest and while smiling as well as the facial physical properties (e.g. viscoelasticity) of both groups were recorded. Differences in terms of physical properties and facial displacement while smiling between the two groups were examined. To examine the relationship between facial surface displacement while smiling and physical properties, a canonical correlation analysis (CCA) was conducted. As a result, three typical abnormal features of smiling in the Cleft group compared with the Control group were noted: less upward and backward displacement on the scar area, downward movement of the lower lip, and a greater asymmetric displacement, including greater lateral displacement of the subalar on the cleft side while smiling and greater alar backward displacement on the non-cleft side. The Cleft group also showed greater elastic modulus at the upper lip on the cleft side, suggesting hardened soft tissue at the scar. The CCA showed that this hard scar significantly affected facial displacement, inducing less upward and backward displacement on the scar area and downward movement of the lower lip in patients with UCLP (correlation coefficient = 0.82, p = 0.04); however, there was no significant relationship between greater nasal alar lateral movement and physical properties of the skin at the scar. Based on these results, personalizing treatment options for dysfunction in facial expression generation may require quantification of the 3D facial morphology and physical properties of facial soft tissues.
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Affiliation(s)
- Donghoon Lee
- Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
| | - Chihiro Tanikawa
- Graduate School of Dentistry, Osaka University, Suita, Osaka, Japan
- Center for Advanced Medical Engineering and Informatics, Osaka University, Suita, Osaka Japan
- * E-mail: ,
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Kanavakis G, Silvola AS, Halazonetis D, Lähdesmäki R, Pirttiniemi P. Profile shape variation and sexual dimorphism amongst middle-aged Northern Europeans. Eur J Orthod 2021; 44:30-36. [PMID: 33822026 DOI: 10.1093/ejo/cjab004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AIM To explore profile shape variation in a large population of middle-aged individuals and investigate features of sexual dimorphism. MATERIALS AND METHODS Facial profile photographs of 1776 individuals (964 females and 812 males; 46 years old), members of the Northern Finland Birth Cohort 1966 (NFBC1966), were uploaded and digitized with Viewbox software. Profile shape was defined with 47 landmarks (4 fixed and 43 sliding semi-landmarks). Digitized images were reoriented and scaled with Procrustes Superimposition, and shape variation was determined with a Principal Component Analysis. RESULTS More than 90 per cent of profile shape variation was explained by Principal Components (PC) 1-9. PC1, explaining the largest amount of variation (33.1 per cent) described changes in facial convexity, slope of the forehead, lip, and chin protuberance. PC2 (23.1 per cent variation) was more related to vertical changes of the lower facial third and PC3 (11 per cent variation) primarily described changes in lip protrusion and nasal projection. Shape analysis showed a significant difference between the average female and the average male profile shape (P < 0.001); however, this was not evident upon visual observation. The shape variable most associated with sex was PC3 (η 2 = 0.245; P < 0.001), which described changes in lip prominence and in projection of the dorsal nasal surface. An additional discriminant analysis showed that profile shape predicted sex in 76 per cent of males and 79.6 per cent of females. CONCLUSIONS There is significant sexual dimorphism in facial profile among middle-aged adults. Profile shape variation was associated to changes in lip protrusion, nasal protuberance, and chin projection.
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Affiliation(s)
- Georgios Kanavakis
- Department of Pediatric Oral Health and Orthodontics, UZB-University Center for Dental Medicine, University of Basel, Basel, Switzerland.,Department of Orthodontics and Dentofacial Orthopedics, Tufts University School of Dental Medicine, Boston, MA, USA.,Oral Development and Orthodontics, Research Unit of Oral Health Sciences, Medical Faculty, University of Oulu, Oulu,Finland
| | - Anna-Sofia Silvola
- Oral Development and Orthodontics, Research Unit of Oral Health Sciences, Medical Faculty, University of Oulu, Oulu,Finland.,Oral and Maxillofacial Department, Oulu University Hospital, Medical Research Center Oulu (MRC Oulu), Oulu, Finland
| | - Demetrios Halazonetis
- Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece
| | - Raija Lähdesmäki
- Oral Development and Orthodontics, Research Unit of Oral Health Sciences, Medical Faculty, University of Oulu, Oulu,Finland.,Oral and Maxillofacial Department, Oulu University Hospital, Medical Research Center Oulu (MRC Oulu), Oulu, Finland
| | - Pertti Pirttiniemi
- Oral Development and Orthodontics, Research Unit of Oral Health Sciences, Medical Faculty, University of Oulu, Oulu,Finland.,Oral and Maxillofacial Department, Oulu University Hospital, Medical Research Center Oulu (MRC Oulu), Oulu, Finland
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Rostovtseva VV, Mezentseva AA, Windhager S, Butovskaya ML. Second-to-fourth digit ratio and facial shape in Buryats of Southern Siberia. Early Hum Dev 2020; 149:105138. [PMID: 32750625 PMCID: PMC7374133 DOI: 10.1016/j.earlhumdev.2020.105138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/08/2020] [Accepted: 07/14/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND The 2nd-to-4th digit ratio (2D:4D) is a putative predictor of a prenatal exposure to sex hormones. 2D:4D is sexually dimorphic (males < females). Studies, linking digit ratio and full facial shapes among Europeans, show that a low 2D:4D is associated with a set of male-specific facial features. Buryats - Mongolian people from Southern Siberia - demonstrate a different pattern of facial sexual dimorphism than Europeans (narrower and more vertically elongated faces in men as opposed to women). AIM The aim of the present study was to investigate the association between facial shape and the 2D:4D in comparison to the pattern of facial sexual dimorphism in Buryats. SUBJECTS Buryats: 88 men and 80 women aged 20 ± 2 years. OUTCOME MEASURES To assess relationship between facial shape and 2D:4D we used a geometric morphometric approach based on standardized full-face frontal photographs and direct measurements of the digit lengths among right-handed individuals. RESULTS The results revealed that 2D:4D was associated with facial morphology in Buryat men, and to a lesser extent in women. Narrower faces, elongated in the vertical direction, and a narrower lower facial outline, were characteristic of Buryat men with low 2D:4D ratios, which corresponded to the male-like facial shapes in Buryats. CONCLUSIONS In Europeans, such facial features were reported for men with a high 2D:4D, which corresponded more to female-like European facial shapes. Hence, our results show that sex-specific morphogenesis in humans is multidirectional, and that digit ratio is capable of predicting sex-specific facial traits even in populations with differing sexually-dimorphic morphology.
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Affiliation(s)
- Victoria V. Rostovtseva
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninskiy pr-t 32a, Moscow 119334, Russia,Corresponding author
| | - Anna A. Mezentseva
- Department of Ethnology, Lomonosov Moscow State University, Lomonosovskiy pr-t 27/4, Moscow 119192, Russia
| | - Sonja Windhager
- Department of Evolutionary Anthropology, University of Vienna, Althanstrasse 14, Vienna 1090, Austria
| | - Marina L. Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Leninskiy pr-t 32a, Moscow 119334, Russia,National Research University Higher School of Economics, Myasnitskaya str. 20, Moscow 101000, Russia
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Surface-based 3-dimensional cephalometry: An objective analysis of cranio-mandibular morphology. Am J Orthod Dentofacial Orthop 2020; 158:535-546. [PMID: 32826124 DOI: 10.1016/j.ajodo.2019.09.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/01/2019] [Accepted: 09/01/2019] [Indexed: 11/23/2022]
Abstract
INTRODUCTION The purpose of this study was to apply a previously reported homologous model for quantifying and visualizing the three-dimensional (3D) cranio-mandibular morphology. METHODS Twenty-eight 3D cone-beam computed tomography (CBCT) images of Japanese patients (7 to 13 years of age) showing skeletal Class 1 malocclusions were used in this study. Wire mesh fitting was conducted for each patient based on the assignment of landmarks to each 3D surface (homologous modeling). Cranial and mandibular images were generated using surface rendering of the CBCT images. The mean and standard deviation of each point on the wire mesh were calculated as the normative mean. Two operators conducted the process twice for seven patients, with a one-week interval between fittings. The intra- and inter-examiner reliability were determined using the 95% confidence interval minimal detectable change (MDC95) for random error and intra-class correlation coefficients (ICCs). RESULTS The intra- and inter-examiner reliability of the mesh fitting method were almost perfect. Normative ranges of the cranial and mandibular surfaces of Japanese were determined. CONCLUSIONS A clinical method that enables practitioners to quantify and visualize the hard tissues of a patient's face in three dimensions with almost perfect reliability is presented. This method allows practitioners to evaluate how patients' skeletal characteristics differ from normative means in three dimensions.
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Rostovtseva VV, Mezentseva AA, Windhager S, Butovskaya ML. Sexual dimorphism in facial shape of modern Buryats of Southern Siberia. Am J Hum Biol 2020; 33:e23458. [PMID: 32596969 DOI: 10.1002/ajhb.23458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVES The aim of the present study was to investigate sexual dimorphism in the full facial shape of modern Buryats-people of Southern Siberia of Mongolian origin. METHODS For this purpose, we have used geometric morphometrics based on standardized full-face frontal photographs. This allowed us to assess and visualize differences in facial shapes between Buryat men (n = 98) and women (n = 89). To specify the facial areas, where the differences occurred, we have complemented our analysis with standard anthropometric facial parameters based on approximations to the craniofacial and mandibular landmarks and soft-tissue morphology of specific facial areas. RESULTS Our results revealed that Buryat women have a set of sexually dimorphic features similar to those reported earlier for other Asian populations (a relatively wider and vertically shorter lower face, more round visible areas of the eyes, relatively narrower noses, smaller mouths, larger [in vertical dimension] foreheads, and relatively thinner upper lips, when compared to Buryat males). At the same time, Buryat women had a specific characteristic, distinguishing them from other world populations-a significantly higher upper face width-to-height ratio (fWHR) compared to males. This indicates that the high fWHR is not a universally male feature in humans, which raises a question of underlying developmental mechanisms. CONCLUSIONS Our results clearly demonstrate that some elements of sexually dimorphic facial shapes may differ across populations with different genetic and ecological backgrounds, and suggest that universal mechanisms of sex-specific facial morphogenesis still need to be clarified in the future.
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Affiliation(s)
| | - Anna A Mezentseva
- Department of Ethnology, Lomonosov Moscow State University, Moscow, Russia
| | - Sonja Windhager
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Marina L Butovskaya
- Institute of Ethnology and Anthropology, Russian Academy of Sciences, Moscow, Russia
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Imaizumi K, Taniguchi K, Ogawa Y, Matsuzaki K, Maekawa H, Nagata T, Mochimaru M, Kouchi M. Three-dimensional shape variation and sexual dimorphism of the face, nose, and mouth of Japanese individuals. Forensic Sci Int 2019; 302:109878. [PMID: 31377687 DOI: 10.1016/j.forsciint.2019.109878] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 07/10/2019] [Accepted: 07/12/2019] [Indexed: 11/30/2022]
Abstract
Three-dimensional (3D) shape variations of the face and facial parts in Japanese adults were examined to collect basic data to be used for facial comparison in forensics. In total, 1000 3D facial scans (500 males, 500 females) of Japanese individuals were re-meshed into anatomically homologous shape models and analyzed by principal component analysis (PCA) after Procrustes superimposition. Facial parts (the nose and the mouth) were segmented from homologous face models and analyzed by PCA, too. Among all kinds of objects (the face, the nose, and the mouth), the most predominant shape variation represented by the first principal component (PC1) was the height-width proportion. The second largest variation (PC2) in the face and the nose was depth; for the mouth, it was the relative protrusion of the upper and lower lips. We interpreted predominant shape variations represented by the first five principal components (PCs) in each object. Asymmetric shape variations were observed within these PCs for the nose and the mouth. Sexual dimorphism of the face and the facial parts was also examined by testing the significance of sex-linked differences in PC scores. A significant difference was found between males and females for many PCs. Sexual dimorphism was examined also by emphasizing the shape difference between average male and female faces. Our results revealed predominant 3D shape variations and sexual dimorphism of the face and facial parts. The results may be informative for performing facial comparison in police investigations, an increasingly used technique.
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Affiliation(s)
- Kazuhiko Imaizumi
- Second Forensic Biology Section, National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba 277-0882, Japan.
| | - Kei Taniguchi
- Second Forensic Biology Section, National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba 277-0882, Japan
| | - Yoshinori Ogawa
- Second Forensic Biology Section, National Research Institute of Police Science, 6-3-1, Kashiwanoha, Kashiwa-shi, Chiba 277-0882, Japan
| | - Kazutoshi Matsuzaki
- Mizuho Information & Research Institute, Inc., 2-3, Kanda-Nishiki-cho, Chiyodak-ku, Tokyo 101-8443, Japan
| | - Hidemasa Maekawa
- Mizuho Information & Research Institute, Inc., 2-3, Kanda-Nishiki-cho, Chiyodak-ku, Tokyo 101-8443, Japan
| | - Takeshi Nagata
- Mizuho Information & Research Institute, Inc., 2-3, Kanda-Nishiki-cho, Chiyodak-ku, Tokyo 101-8443, Japan; School of Integrative and Global Majors, Program in Human Biology, University of Tsukuba, 1-1-1, Tennodai, Tsukuba-shi, Ibaraki 305-8577, Japan
| | - Masaaki Mochimaru
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, 2-3-26, Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Makiko Kouchi
- Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology, 2-3-26, Aomi, Koto-ku, Tokyo 135-0064, Japan
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Tanikawa C, Takata S, Takano R, Yamanami H, Edlira Z, Takada K. Functional decline in facial expression generation in older women: A cross-sectional study using three-dimensional morphometry. PLoS One 2019; 14:e0219451. [PMID: 31291323 PMCID: PMC6636602 DOI: 10.1371/journal.pone.0219451] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/24/2019] [Indexed: 11/18/2022] Open
Abstract
Elderly people show a decline in the ability to decode facial expressions, but also experience age-related facial structure changes that may render their facial expressions harder to decode. However, to date there is no empirical evidence to support the latter mechanism. The objective of this study was to assess the effects of age on facial morphology at rest and during smiling, in younger (n = 100; age range, 18-32 years) and older (n = 30; age range, 55-65 years) Japanese women. Three-dimensional images of each subject's face at rest and during smiling were obtained and wire mesh fitting was performed on each image to quantify the facial surface morphology. The mean node coordinates in each facial posture were compared between the groups using t-tests. Further, the node coordinates of the fitted mesh were entered into a principal component analysis (PCA) and a multifactor analysis of variance (MANOVA) to examine the direct interactions of aging and facial postures on the 3D facial morphology. The results indicated that there were significant age-related 3D facial changes in facial expression generation and the transition from resting to smiling produced a smaller amount of soft tissue movement in the older group than in the younger group. Further, 185 surface configuration variables were extracted and the variables were used to create four discriminant functions: the age-group discrimination for each facial expression, and the facial expression discrimination for each age group. For facial expression discrimination, the older group showed 80% accuracy with 2 of 66 significant variables, whereas the younger group showed 99% accuracy with 15 of 144 significant variables. These results indicate that in both facial expressions, the facial morphology was distinctly different in the younger and older subjects, and that in the older group, the facial morphology during smiling could not be as easily discriminated from the morphology at rest as in the younger group. These results may help to explain one aspect of the communication dysfunction observed in older people.
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Affiliation(s)
- Chihiro Tanikawa
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School
of Dentistry, Osaka University, Suita, Osaka, Japan
- Center for Advanced Medical Engineering and Informatics, Osaka
University, Suita, Osaka, Japan
| | - Sadaki Takata
- Department of Fashion & Beauty Sciences, Osaka Shoin Women’s
University, Higashi-Osaka, Osaka, Japan
| | - Ruriko Takano
- Corporate Culture Department, Shiseido Co., ltd., Tokyo,
Japan
| | - Haruna Yamanami
- Shiseido Global Innovation Center, Shiseido Co., ltd., Yokohama,
Kanagawa, Japan
| | - Zere Edlira
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School
of Dentistry, Osaka University, Suita, Osaka, Japan
| | - Kenji Takada
- Center for Advanced Medical Engineering and Informatics, Osaka
University, Suita, Osaka, Japan
- Faculty of Dentistry, National University of Singapore, Singapore,
Republic of Singapore
- * E-mail:
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Tebbens M, Nota NM, Liberton NPTJ, Meijer BA, Kreukels BPC, Forouzanfar T, Verdaasdonk RM, den Heijer M. Gender-Affirming Hormone Treatment Induces Facial Feminization in Transwomen and Masculinization in Transmen: Quantification by 3D Scanning and Patient-Reported Outcome Measures. J Sex Med 2019; 16:746-754. [PMID: 30926514 DOI: 10.1016/j.jsxm.2019.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Hormone treatment induces feminization of the body in transwomen and masculinization in transmen. However, the effect of hormone treatment on facial characteristics is still unknown. AIM We aimed to study whether hormone treatment induces facial feminization and masculinization and how this potential change affects satisfaction and self-esteem. METHODS In this single-center cohort study, we included 27 transwomen and 15 transmen who received standardized hormone treatment in the Center of Expertise on Gender Dysphoria, VU University Medical Center Amsterdam. Facial 3-dimensional images were obtained at baseline and at 3 and 12 months. At each image, 22 facial landmarks were placed. Furthermore, the FACE-Q Satisfaction with Facial Appearance Overall and the Rosenberg self-esteem scale were obtained at the same measurement points. MAIN OUTCOME MEASURES The main outcome measures included the relative local shift of skin in millimeters in the 22 landmarks in the transverse (x-axis), coronal (y-axis), and sagittal (z-axis) anatomic axes, the color maps, and the outcomes of the questionnaires. RESULTS After 12 months, cheek tissue in transwomen increased, with 0.50 mm (95% CI 0.04-0.96) in the x-axis and 1.08 mm (95% CI 0.31-1.85) in the z-axis. Tissue in the jaws decreased with -0.60 mm (95% CI -1.28-0.08) in the x-axis and -0.18 mm (95% CI -0.03-0.33) in the y-axis. Cheek tissue in transmen decreased with -0.45 mm (95% CI -1.00-0.11) in the x-axis and -0.84 mm (95% CI -1.92-0.25) in the z-axis. These changes already started after 3 months. An increase in satisfaction with the facial appearance was found in both transwomen and transmen. There were no changes in reported self-esteem. CLINICAL IMPLICATION These results could lead to more realistic expectations of facial changes. Furthermore, our results suggest that the face continues to change for at least a year, which could suggest that performing facial feminization surgery after 1 year of hormone treatment might be too early. STRENGTH & LIMITATIONS This study is the first that provides insight into the facial changes in transgender individuals receiving hormone treatment, and it introduces an objective method to examine (small) facial changes. Our study is limited by the poor reliability of the landmarks, the difficulty of facial fixation, and the lack of gender-specific questions in the questionnaires. CONCLUSIONS Hormone treatment in transwomen induces an increase in cheek tissue and a decrease in jaw tissue. In transmen a tendency of decrease in cheek tissue and an increase in jaw tissue was found. These changes are in the direction of the desired gender. Tebbens M, Nota NM, Liberton NPTJ, et al. Gender-Affirming Hormone Treatment Induces Facial Feminization in Transwomen and Masculinization in Transmen: Quantification by 3D Scanning and Patient-Reported Outcome Measures. J Sex Med 2019;16:746-754.
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Affiliation(s)
- Marieke Tebbens
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Internal Medicine, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - Nienke M Nota
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Internal Medicine, Amsterdam Movement Sciences, Amsterdam, the Netherlands
| | - Niels P T J Liberton
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physics and Medical Technology, 3D InnovationLab, Amsterdam, the Netherlands
| | - Brigitte A Meijer
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Oral and Maxillofacial Surgery, Amsterdam, the Netherlands
| | - Baudewijntje P C Kreukels
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Medical Psychology and Center of Expertise on Gender Dysphoria, Amsterdam, the Netherlands
| | - Tim Forouzanfar
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Oral and Maxillofacial Surgery, Amsterdam, the Netherlands
| | - Rudolf M Verdaasdonk
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Physics and Medical Technology, 3D InnovationLab, Amsterdam, the Netherlands
| | - Martin den Heijer
- Amsterdam UMC, Vrije Universiteit Amsterdam, Department of Internal Medicine, Amsterdam Movement Sciences, Amsterdam, the Netherlands.
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Tanikawa C, Akcam MO, Takada K. Quantifying faces three-dimensionally in orthodontic practice. J Craniomaxillofac Surg 2019; 47:867-875. [PMID: 30926238 DOI: 10.1016/j.jcms.2019.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/21/2018] [Accepted: 02/27/2019] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The purpose of this study was to formulate and demonstrate a method for quantifying and visualizing the three-dimensional (3-D) configuration of the soft tissues of the face at rest to facilitate a quantitative and instantaneous understanding of a patient's static facial form characteristics. MATERIALS AND METHODS 3-D facial images of 200 Japanese adult volunteers at rest were recorded using a 3-D photogrammetric system. For each participant, a wire mesh fitting was conducted based on the assignment of landmarks to each 3-D facial image. This method generated 6,017 points on the wire mesh (i.e., the nodes of the fitted mesh). For each point, the mean and standard deviation were calculated and used for patient evaluation. The system performance was exemplified with three orthodontic patients with skeletal Class II and III malocclusions and laterotrusion. RESULTS Three patients with severe skeletal Class II and III deformities and laterotrusion were evaluated with the proposed method. CONCLUSION A clinical method for practitioners to quantify and visualize the soft tissues of a patient's face in 3 dimensions has been presented with clinical applications and considerations. This method allows practitioners to evaluate how patients' facial characteristics differ from normative faces.
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Affiliation(s)
- Chihiro Tanikawa
- Graduate School of Dentistry, Osaka University, Suita, Osaka, 5650871, Japan; Global Center for Advanced Medical Engineering and Informatics, Osaka University, Suita, Osaka, 5650871, Japan.
| | - M Okan Akcam
- Department of Orthodontics, School of Dentistry, Ankara University, Ankara, Turkey
| | - Kenji Takada
- Global Center for Advanced Medical Engineering and Informatics, Osaka University, Suita, Osaka, 5650871, Japan; Faculty of Dentistry, National University of Singapore, Singapore, 119083, Republic of Singapore
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Gonzales PS, Machado CEP, Michel-Crosato E. Photoanthropometry of the Face in the Young White Brazilian Population. Braz Dent J 2018; 29:619-623. [PMID: 30517486 DOI: 10.1590/0103-6440201802027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/16/2018] [Indexed: 11/22/2022] Open
Abstract
The aim of the present study is to describe the simplified facial pattern of young Brazilian men and women using the facial index (FI), upper face index (UFI), and nasal index (NI) in indirect anthropometric measurements applied to frontal photographic images. The images were obtained from 660 adult white men and 689 adult white women aged 30 years ± 6 months, and classified according to regions of birth, as follows: south (S), southeast (SE), midwest (MW), northeast (NE), and north (N). The nasion, zygion, gnathion, stomion, subnasale, and alare landmarks were labeled on the images using the SAFF 2D® software. Based on the coordinates, the linear distances between the landmarks of interest were calculated and presented as indices. The analysis of variance and Student's t-test were used for assessing the regions of birth and gender, respectively. The collected data allowed obtaining the facial profile of the young adult Brazilian population. There were differences in the facial profiles between men and women and also between some regions, especially between the N and the other Brazilian regions (p<0.05). The UFI did not show a statistically significant difference (p>0.05) between genders for any of the regions. The discriminant analysis for gender assessment demonstrated higher accuracy when the three indices were analyzed together. In the decision tree for gender assessment, the NI showed better results than the other indices.
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Affiliation(s)
- Paola Sampaio Gonzales
- Community Dentistry Department, School of Dentistry, USP- Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Edgard Michel-Crosato
- Community Dentistry Department, School of Dentistry, USP- Universidade de São Paulo, São Paulo, SP, Brazil
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Oliva B, Sferra S, Greco AL, Valente F, Grippaudo C. Three-dimensional analysis of dental arch forms in Italian population. Prog Orthod 2018; 19:34. [PMID: 30198054 PMCID: PMC6129455 DOI: 10.1186/s40510-018-0233-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/10/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of this study was the comparison of male and female upper and lower dental arch form in untreated Italian patients by 3D analysis, to find differences in shape, in transversal and longitudinal diameters between sexes, and to give a representative set of population's dental arch to clinicians in order to provide suitable orthodontic treatment. METHODS The sample consisted of 3D scans of dental casts deriving from 104 Italian untreated patients (Male = 35, Female = 69) in permanent dentition. An evaluation of the arch form was performed by angular and linear values on every patient using a 3D software (SolidWorks®). A Student's two-tailed t test was used to determine if the differences in measurements between the male and female groups were significant and the level of significance was set at P < 0.05. RESULTS Statistically significant differences in upper and lower transversal and longitudinal diameters were found. Male arch widths were significantly larger than those of females. Male intercanine, intermolar, and interpremolar diameters were significantly greater than females. Dental arch depth was significantly smaller in the female group. Anterior upper dental arch form was flatter, wider, and less sharp in the female group. CONCLUSIONS Basing on the anatomical arches differences found between sexes concerning Italian patients, it is suggested to have regard to each patient pre-treatment arch form, width, and depth during orthodontic treatment according to gender.
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Affiliation(s)
- Bruno Oliva
- Institute of Catholic University of Sacred Heart, Largo Francesco Vito 1, 00198, Rome, Italy
| | - Simone Sferra
- Institute of Catholic University of Sacred Heart, Largo Francesco Vito 1, 00198, Rome, Italy.
| | - Anna Lucia Greco
- Institute of Catholic University of Sacred Heart, Largo Francesco Vito 1, 00198, Rome, Italy
| | - Francesco Valente
- University G. d'Annunzio of Chieti-Pescara, Via dei Vestini 31, 66100, Chieti, Italy
| | - Cristina Grippaudo
- Institute of Catholic University of Sacred Heart, Largo Francesco Vito 1, 00198, Rome, Italy
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Tanikawa C, Takada K. Test-retest reliability of smile tasks using three-dimensional facial topography. Angle Orthod 2018; 88:319-328. [PMID: 29509027 DOI: 10.2319/062617-425.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES To evaluate the test-retest reliability of three types of facial expression tasks using three-dimensional (3D) facial topography. MATERIALS AND METHODS Twelve adult volunteers were enrolled in this study. They were instructed to perform three different facial expression tasks: rest posture, posed smile, and maximum effort smile. Each task was recorded using a 3D image-capturing device on two separate occasions with an interval of 1 week between sessions. The images of two sessions were superimposed based on the forehead. For each participant and for each facial expression, a wire mesh fitting was conducted. This method generated 6,017 points on the wire mesh. Intraindividual reliability between sessions for each task was statistically tested by intraclass correlation coefficients (ICCs) and the 95% confidence interval minimal detectable change (MDC95). RESULTS The MDC95 for the repeated measures of the rest posture, posed smile, and maximum effort smile exhibited means of 0.8, 1.5, and 1.3 mm, respectively, on the z-axis. The ICCs ranged from substantial to almost perfect agreement for repeated measures for the rest posture and maximum effort smile (0.60 < ICC ≤ 1.00). The right corner of the mouth in the posed smile showed moderate agreement (0.40 < ICC ≤ 0.60). CONCLUSIONS The overall test-retest reliability of the maximum effort smile and rest posture showed substantial to almost perfect agreement, and this was clinically acceptable.
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Kono K, Tanikawa C, Yanagita T, Kamioka H, Yamashiro T. A Novel Method to Detect 3D Mandibular Changes Related to Soft-Diet Feeding. Front Physiol 2017; 8:567. [PMID: 28855872 PMCID: PMC5557733 DOI: 10.3389/fphys.2017.00567] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 07/20/2017] [Indexed: 11/13/2022] Open
Abstract
Craniofacial morphology varies among individuals, which is regulated by the interaction between genes and the environment. Soft-diet feeding is a widely-used experimental model for studying the association between the skeletal morphology and muscle-related loading on the bone. Traditionally, these studies have been based on linear and angular measurements provided on two-dimensional (2D) radiographs in the lateral view. However, 2D observation is based on simplification of the anatomical structures and cannot detect three-dimensional (3D) changes in detail. In this study, we newly developed a modified surface-based analysis with micro-3D computed tomography (CT) to examine and detect the 3D changes in the mandible associated with soft-diet feeding. Mice at 3 weeks of age were fed a powdered soft-diet (SD) or hard-diet (HD) of regular rodent pellets until 9 weeks of age. Micro-CT images were taken at age 9 weeks to reconstruct the anatomical architecture images. A computer-generated averaged mandible was superimposed to directly visualize the morphological phenotypes. Gross observation revealed the apparent changes at the posterior body of the mandible, the angular process and the condyle between HD and SD mice. Significant differences in the mapping indicated the regions of significant displacement in the SD mice over the averaged 3D image of the HD mice. This map revealed that vertical displacement was most evident in 3D changes. We also noted a combination of vertical, transverse and anteroposterior directions of displacement in the condylar growth, resulting in complicated shape changes in the whole condylar process in SD mice. In contrast, transverse displacement was more significant in the coronoid process. The map analysis further showed the significant outward displacement of the inner surface of the alveolar process, which consequently resulted in thinning of the alveolar process.
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Affiliation(s)
- Kana Kono
- Department of Orthodontics, Okayama University HospitalOkayama, Japan
| | - Chihiro Tanikawa
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka UniversityOsaka, Japan
| | - Takeshi Yanagita
- Department of Orthodontics, Okayama University HospitalOkayama, Japan
| | - Hiroshi Kamioka
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama UniversityOkayama, Japan
| | - Takashi Yamashiro
- Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Osaka UniversityOsaka, Japan
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Matthews H, Penington T, Saey I, Halliday J, Muggli E, Claes P. Spatially dense morphometrics of craniofacial sexual dimorphism in 1-year-olds. J Anat 2016; 229:549-59. [PMID: 27338586 DOI: 10.1111/joa.12507] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2016] [Indexed: 01/28/2023] Open
Abstract
Recent advances in the field of geometric morphometrics allow for powerful statistical hypothesis testing for effects of biological and environmental variables on anatomical shape. This study used partial least-squares regression (PLSR) and the recently developed bootstrapped response-based imputation modelling (BRIM) algorithm to test for sexual dimorphism in the craniofacial shape of 1-year-old humans. We observed a recession of the forehead in boys relative to girls, and differences in the nose, consistent with adult dimorphism. Results also suggest that the degree to which individuals express dimorphic traits is continuous throughout the population. This is also seen in adult dimorphism but in 1-year-olds the amount of overlap between groups is much higher, indicating the strength of dimorphism between sexes is lower. Our results demonstrate early sexual dimorphism that is not attributable to the influx of sex hormones at puberty. This highlights the need to look at very early ontogeny for the origins of sexual dimorphism. We suggest that future work look at potential mediating effects of this early dimorphism on the later impact of puberty. The subtle shape differences we have detected, may also be applied to sexing fossilised crania. A common artefact in 3D images of faces of young children is that they often have their mouths open to varying degrees, introducing variability in the data unrelated to anatomy. We describe two PLSR-based methods of correcting this. These methods may facilitate surgical planning and assessment of young children based on 3D images.
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Affiliation(s)
- Harold Matthews
- Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Royal Children's Hospital, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Tony Penington
- Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Royal Children's Hospital, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Ine Saey
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium.,ESAT/PSI, Medical Image Computing, UZ Leuven, Medical Imaging Research Center, Leuven, Belgium
| | - Jane Halliday
- Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Evelyn Muggli
- Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Peter Claes
- Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Electrical Engineering, KU Leuven, Leuven, Belgium.,ESAT/PSI, Medical Image Computing, UZ Leuven, Medical Imaging Research Center, Leuven, Belgium
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Zheng W, Yang Q, Peng K, Yu F. What's in the Chinese Babyface? Cultural Differences in Understanding the Babyface. Front Psychol 2016; 7:819. [PMID: 27303360 PMCID: PMC4886646 DOI: 10.3389/fpsyg.2016.00819] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 05/17/2016] [Indexed: 11/13/2022] Open
Abstract
We investigated the cultural differences in understanding and reacting to the babyface in an effort to identify both cultural and gender biases in the universal hypothesis that the babyfaced individuals are perceived as naïve, cute, innocent, and more trustworthy. Sixty-six Chinese and Sixty-six American participants were required to evaluate Chinese faces selected from the Chinese Academy of Sciences (CAS)—Pose, Expression, Accessories, and Lighting (PEAL) Large-Scale Chinese Face Database. In our study, we applied Active Shape Models, a modern technique of machine learning to measure facial features. We found some cultural similarities and also found that a Chinese babyface has bigger eyes, higher eyebrows, a smaller chin, and greater WHR (Facial width-to-height ratio), and looks more attractive and warmer. New findings demonstrate that Chinese babyfaces have a lower forehead and closer pupil distance (PD). We found that when evaluating the babyfacedness of a face, Chinese are more concerned with the combination of all facial features and American are more sensitive to specific highlighted babyfaced features. The Chinese babyface tended to be perceived as more babyfaced for American participants, but not less competent for Chinese participants.
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Affiliation(s)
- Wenwen Zheng
- Department of Psychology, Tsinghua University Beijing, China
| | - Qian Yang
- Department of Public Health, Zhejiang University Hangzhou, China
| | - Kaiping Peng
- Department of Psychology, Tsinghua University Beijing, China
| | - Feng Yu
- Department of Leadership and Organization Management, School of Economics and Management, Tsinghua University Beijing, China
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Danel DP, Dziedzic-Danel A, Kleisner K. Does age difference really matter? Facial markers of biological quality and age difference between husband and wife. HOMO-JOURNAL OF COMPARATIVE HUMAN BIOLOGY 2016; 67:337-47. [PMID: 27238548 DOI: 10.1016/j.jchb.2016.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 02/29/2016] [Indexed: 11/15/2022]
Abstract
Information conveyed by facial attractiveness markers such as averageness, bilateral symmetry, and secondary sexual characteristics may play an important adaptive role in human sexual selection. Nonetheless, mate choice also relies on other non-physical characteristics such as, for instance, an individual's age. Women prefer and enter in relationships with older partners, whereas in men the inverse relation is observed. Surprisingly, the link between facial morphological markers of biological quality on the one hand and age disparity between partners on the other hand has been as yet subject of very little research. This study aims to fill this gap. We had used facial photographs and demographic data of heterosexual marriages. Facial cues of biological quality, such as averageness, bilateral symmetry, and sexual dimorphism, were digitally measured using geometric morphometric methods and then associated with spouses' age difference. It turned out that a greater age disparity between spouses correlates, in both partners, with higher scores in facial measures which indicate partners' biological quality. One exception is female facial masculinity - generally regarded as an unattractive marker of a low biological quality - which, too, is associated with higher spouse age disparity. In general, our results show that facial symmetry, averageness, and secondary sexual characteristics may play a role in age-dependent mate choice. We suggest that in marriages where the wife is considerably younger than the husband, wife's greater facial masculinity may increase her perceived age and with it, her perceived maturity.
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Affiliation(s)
- D P Danel
- Polish Academy of Sciences, Anthropology Unit in Wroclaw, Podwale 75, 50-449 Wroclaw, Poland.
| | - A Dziedzic-Danel
- Department of Heart Diseases, Wroclaw Medical University, Weigla 5, 50-981 Wroclaw, Poland
| | - K Kleisner
- Department of Philosophy and History of Sciences, Faculty of Sciences, Charles University in Prague, Viničná 7, 128 44 Praha 2, Czech Republic
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