Face Shape Research Articles

안면인식기술과 개인정보보호

Face recognition technology is a method that utilizes thermal infrared photography, three-dimensional measurement, and skeletal analysis to scan, store, and recognize facial shapes or thermal images. It verifies identity by comparing facial images captured by cameras with those in a stored photo database. This technology is extensively applied in various sectors, such as identity verification and access control, due to its high accuracy and quick identification capabilities. The advancement of facial recognition technology, coupled with CCTV, the Internet of Things (IoT), and widespread network connections, is materializing dystopian fears concerning omnipresent surveillance and the ensuing erosion of privacy. Additionally, biased facial recognition technology may serve as a tool for discrimination, infringing upon the rights and freedoms of minorities and other marginalized groups. In 2023, the National Human Rights Commission of The Republic of Korea issued a statement regarding human rights violations facilitated by facial recognition technology and urged the Speaker of the National Assembly and the Prime Minister to actively respond. The statement highlighted that direct observation of individuals' faces in public spaces by the state could limit citizens' freedom of movement and lead to unwarranted surveillance. Given the unique nature of biometric information, such as facial recognition technology, the repercussions of data breaches and misuse are more severe compared to other types of personal information. Specifically, real-time facial recognition technology that targets an unspecified number of individuals in public spaces without their consent may infringe upon the right to privacy and informational self-determination, as well as other fundamental rights including privacy, freedom of assembly, and freedom of association. Furthermore, real-time facial recognition security systems pose challenges in terms of privacy protection and invasion. Hence, the security of collected facial data, defenses against hacking threats, and the secure management of facial databases require thorough examination. This study explores the legal framework and international legislative trends related to biometric information, including facial recognition technology, to identify measures for protecting personal information and ensuring the safe use of this technology.

Integrative Multi-omics Analysis Identifies Genetic Variants Contributing to Non-syndromic Cleft Lip with or without Cleft Palate.

To provide novel insights into the aetiology of non-syndromic cleft lip with or without cleft palate (NSCL/P) by integrating multi-omics data and exploring susceptibility genes associated with NSCL/P. A two-stage genome-wide association study (GWAS) of NSCL/P was performed, involving a total of 1,069 cases and 1,724 controls. Using promoter capture Hi-C (pCHi-C) datasets in human embryonic stem cells (hESC) and chromatin immunoprecipitation sequencing (ChIP-seq) in craniofacial tissues, we filtered out single nucleotide polymorphisms (SNPs) with active cis-regulation and their target genes. Additionally, we employed expression quantitative trait loci (eQTL) analysis to identify candidate genes. Thirteen SNPs were identified as cis-regulation units associated with the risk of NSCL/P. Five of these were proven to be active in chromatin states in early human craniofacial development (rs7218002: odds ratio [OR] 1.50, P = 8.14E-08; rs835367: OR 0.78, P = 3.48E- 05; rs77022994: OR 0.55, P = 1.05E-04; rs961470: OR 0.73, P = 1.38E-04; rs17314727: OR 0.73, P = 1.85E-04). Additionally, pCHi-C and eQTL analysis prioritised three candidate genes (rs7218002: NTN1, rs835367: FGGY, LINC01135). NTN1 and FGGY were expressed in mouse orofacial development. Deficiencies in NTN1, FGGY and LINC01135 were associated with cleft palate and cleft lip, abnormal facial shape and bifid uvula, and abnormality of the face, respectively. Our study identified five SNPs (rs7218002, rs835367, rs77022994, rs961470 and rs17314727) and three susceptibility genes (NTN1, FGGY and LINC01135) associated with NSCL/P. These findings contribute to a better understanding of the genetic factors involved.

Frontal facial analysis of female celebrity attractiveness standards through artificial intelligence

The contemporary significance of celebrities’ facial aesthetics underscores their heightened importance in shaping attractiveness standards. This retrospective study aimed to investigate the impact of patterns on aesthetic canons in the profile views of female celebrities, using artificial intelligence. The study sought to compare different races and propose standards for attractive faces.In this retrospective cohort study, a Python-based algorithm was used to analyze frontal patterns and evaluate their influence on aesthetic norms in publicly accessible images of female global celebrities. Ten ideal angular or proportional measures were gathered from the literature, and were trained to serve as a benchmark for the analysis of facial attractiveness. Demographic characteristics were described statistically. A one-way ANOVA test was employed to assess data distribution. Differences in means between groups were evaluated using nonparametric independent-sample tests, with statistical significance set at < 0.05.The study involved facial analyses for 115 female celebrities. It revealed variations in facial features among races. The mean golden ratio differed, with African and Asian individuals showing lower ratios. Symmetry varied, with Latin and Caucasian faces considered the most symmetrical. The zygomatic-to-mandibular width ratio was similar across races, with a ratio close to 80% being associated with more attractive faces. Differences in nose-to-mouth ratio, lips, alar base width, and chin angle were noted among race groups.The study concluded that, regardless of race, an attractive female face is characterized by specific ratios and angles. Facial symmetry, though desirable, is not strictly necessary. Irrespective of race background, an appealing female face is characterized by a zygomatic-to-mandibular width ratio nearing 80%, a mid-facial third that is slightly larger than the lower third, and a distinctive chin angle of approximately 138°, contributing to a trapezoidal facial shape. The findings contribute valuable insights into attractiveness standards and the impact of frontal patterns on aesthetic canons in female celebrities.

3D Analysis of the Cranial and Facial Shape in Craniosynostosis Patients: A Systematic Review.

With increasing interest in 3D photogrammetry, diverse methods have been developed for craniofacial shape analysis in craniosynostosis patients. This review provides an overview of these methods and offers recommendations for future studies. A systematic literature search was used to identify publications on 3D photogrammetry analyses in craniosynostosis patients until August 2023. Inclusion criteria were original research reporting on 3D photogrammetry analyses in patients with craniosynostosis and written in English. Sixty-three publications that had reproducible methods for measuring cranial, forehead, or facial shape were included in the systematic review. Cranial shape changes were commonly assessed using heat maps and curvature analyses. Publications assessing the forehead utilized volumetric measurements, angles, ratios, and mirroring techniques. Mirroring techniques were frequently used to determine facial asymmetry. Although 3D photogrammetry shows promise, methods vary widely between standardized and less conventional measurements. A standardized protocol for the selection and documentation of landmarks, planes, and measurements across the cranium, forehead, and face is essential for consistent clinical and research applications.

A common cis-regulatory variant impacts normal-range and disease-associated human facial shape through regulation of PKDCC during chondrogenesis.

Genome-wide association studies (GWAS) identified thousands of genetic variants linked to phenotypic traits and disease risk. However, mechanistic understanding of how GWAS variants influence complex morphological traits and can, in certain cases, simultaneously confer normal-range phenotypic variation and disease predisposition, is still largely lacking. Here, we focus on rs6740960, a single nucleotide polymorphism (SNP) at the 2p21 locus, which in GWAS studies has been associated both with normal-range variation in jaw shape and with an increased risk of non-syndromic orofacial clefting. Using in vitro derived embryonic cell types relevant for human facial morphogenesis, we show that this SNP resides in an enhancer that regulates chondrocytic expression of PKDCC - a gene encoding a tyrosine kinase involved in chondrogenesis and skeletal development. In agreement, we demonstrate that the rs6740960 SNP is sufficient to confer chondrocyte-specific differences in PKDCC expression. By deploying dense landmark morphometric analysis of skull elements in mice, we show that changes in Pkdcc dosage are associated with quantitative changes in the maxilla, mandible, and palatine bone shape that are concordant with the facial phenotypes and disease predisposition seen in humans. We further demonstrate that the frequency of the rs6740960 variant strongly deviated among different human populations, and that the activity of its cognate enhancer diverged in hominids. Our study provides a mechanistic explanation of how a common SNP can mediate normal-range and disease-associated morphological variation, with implications for the evolution of human facial features.

Improving Realism of Facial Interpolation and Blendshapes with Analytical Partial Differential Equation-Represented Physics

How to create realistic shapes by interpolating two known shapes for facial blendshapes has not been investigated in the existing literature. In this paper, we propose a physics-based mathematical model and its analytical solutions to obtain more realistic facial shape changes. To this end, we first introduce the internal force of elastic beam bending into the equation of motion and integrate it with the constraints of two known shapes to develop the physics-based mathematical model represented with dynamic partial differential equations (PDEs). Second, we propose a unified mathematical expression of the external force represented with linear and various nonlinear time-dependent Fourier series, introduce it into the mathematical model to create linear and various nonlinear dynamic deformations of the curves defining a human face model, and derive analytical solutions of the mathematical model. Third, we evaluate the realism of the obtained analytical solutions in interpolating two known shapes to create new shape changes by comparing the shape changes calculated with the obtained analytical solutions and geometric linear interpolation to the ground-truth shape changes and conclude that among linear and various nonlinear PDE-based analytical solutions named as linear, quadratic, and cubic PDE-based interpolation, quadratic PDE-based interpolation creates the most realistic shape changes, which are more realistic than those obtained with the geometric linear interpolation. Finally, we use the quadratic PDE-based interpolation to develop a facial blendshape method and demonstrate that the proposed approach is more efficient than numerical physics-based facial blendshapes.

Cross-cultural perception of strength, attractiveness, aggressiveness and helpfulness of Maasai male faces calibrated to handgrip strength

Previous research has demonstrated that Maasai and Europeans tend to align in their ratings of the physical strength and aggressiveness of Maasai male faces, calibrated to hand grip strength (HGS). However, perceptions of attractiveness of these faces differed among populations. In this study, three morphs of young Maasai men created by means of geometric morphometrics, and depicting the average sample and two extrema (± 4 SD of HGS), were assessed by men and women from Tanzania, Czech Republic, Russia, Pakistan, China, and Mexico (total sample = 1540). The aim of this study was to test cross-cultural differences in the perception of young Maasai men’s composites calibrated to HGS, focusing on four traits: physical strength, attractiveness, aggressiveness, and helpfulness. Individuals from all six cultures were able to distinguish between low, medium, and high HGS portraits. Across all study populations, portrait of Maasai men with lower HGS was perceived as less attractive, more aggressive, and less helpful. This suggests that people from diverse populations share similar perceptions of physical strength based on facial shape, as well as attribute similar social qualities like aggressiveness and helpfulness to these facial images. Participants from all samples rated the composite image of weak Maasai men as the least attractive.

Respiratory fit test panel representing population of Malaysia

BackgroundThe existing respiratory fit test panels (RFTPs) are based on Bivariate and Principal Component Analysis (PCA) which utilise American and Chinese head and facial dimensions. As RFTPs based on local facial anthropometric data for Malaysia are not available, this study was conducted with the aim to develop new RFTPs using Malaysian data.MethodologyA cross-sectional study was conducted across Malaysia among 3,324 participants of the study of National Health and Morbidity Survey 2020 aged 18 and above. Ten head and facial dimensions were measured. Face length and face width were used to construct bivariate facial panel, whereas the scores from the first two PCA were used to develop the PCA panel.ResultsThis study showed that Malaysians have the widest upper limit for facial width. It also found that three factors could be reduced from the PCA analysis. However only 2 factors were selected with PCA 1 representing head and facial size and PCA 2 representing facial shape. Our bivariate panel could accommodate 95.0% of population, while our PCA panel accommodated 95.6%.ConclusionThis was the first study to use Malaysian head and facial anthropometry data to create bivariate and PCA panels. Respirators constructed using these panels are likely to fit ≥ 95.0% of Malaysia’s population.

Gender-expansive listeners invite us to reconsider voice categorization as a simple matter of pitch and timbre

Past literature has focused on pitch and timbre cues as the main determinants of the voice of an actor (a speaker or a singer). But in real life, judges rely on non-auditory cues such as the actor’s facial features, height, body size and shape. Resisting these visual biases could provide more accurate assessment of a voice but requires a stronger dissociation between auditory attributes and physical appearance, an ability hypothetically acquired by gender-expansive participants. In three online studies, we examine Faching (allocating voices into traditional categories). In study 1, 166 participants (85 cis, 81 gender-expansive) rated 144 audio (A) samples from 18 different actors (3 from each major Fach category, excluding countertenor) along a slider labeled low/dark to high/bright. Participants then guessed the voice types of the same actors in silent videos (V), before rating them in AV combinations. The cis group exhibited 30% more visual bias than the gender-expansive group. To further understand how gender-expansive participants obtain this benefit, we manipulated the fundamental frequency (in study 2) or the vocal tract length (in study 3) by ± 3 semitones from the original stimuli. Preliminary findings suggest that the two groups differ in the face of timbre but not pitch manipulations.

Rotation of a Part of the Composite Flap for Simultaneous Gonion Reduction and Malar Augmentation During Rhytidectomy in Asians.

The desired facial shape that Asians aim to achieve through plastic surgery differs from that of westerners. The author facilitates facial volume deflation by using the rotation of a part of the composite flap to the malar area resulting in volumetric augmentation during rhytidectomy; simultaneously, a volumetric reduction was implemented in the gonion. Extended deep plane rhytidectomy with the rotation of a part of the composite flap was performed in 49 patients, whereas extended deep plane rhytidectomy without the rotation of a part of the composite flap was performed in 20 patients. For the results, the satisfaction survey of the surgery was conducted in all patients and by 2 surgeons during a follow-up visit 12 months later. To assess the surgical outcome objectively, the author used the Allergan photometric midface volume deficit scale to measure the midface volume. The midface contour and degree of projection were analyzed using lateral view photographs of the patients. The measurement of segment CM (distance between the lateral canthus and mouth corner) and segment MA (distance from segment CM to the most protruding malar area) was performed. The patients who underwent extended deep plane rhytidectomy with the rotation of a part of the composite flap reported higher overall satisfaction and achieved more favorable results, as evaluated by the 2 aesthetic surgeons (P < 0.05). The scores on the Allergan photometric midface volume deficit scale showed a significant increase before and after the surgery in both groups (P < 0.05), also as evaluated by the 2 aesthetic surgeons. However, the change in scores was found to be higher in the extended deep plane rhytidectomy with the rotation of a part of the composite flap group. The midface contour and degree of projection showed an increase of 20.6% on the right face and 22.7% on the left face, respectively (P < 0.001). Using the rotation of a part of the composite flap during rhytidectomy resulted in overall satisfactory outcomes for all patients. Based on these findings, it can be concluded that the use of this surgical method is beneficial and effective.

Cultural Predictors of Facial Ethnicity Preference in the Miskitu and Mestizos of Rural Nicaragua

Both basic visual experience and cultural associations with race and ethnicity may contribute to the extent observers do or do not favor some facial ethnicity cues over others. Given that visual media contain a highly biased selection of faces, with Whiteness both over-represented and strongly privileged in film and television, communities for whom visual media are relatively novel may experience an additional, pervasive source of attitudes to facial ethnicity markers. In the current research, we compared individuals of Mestizo and Miskitu identities living in communities on the Caribbean Coast of Nicaragua with, and without, regular access to television on their relative preference for facial stimuli manipulated to look more or less White (Black vs White, Black vs Mestizo, Mestizo vs White). Results showed that all communities showed an overall preference for images with lighter skin, although changes in facial shape did not affect preferences. Those who had attended more years of education preferred whiter faces than those with less education, and those who watched more television preferred whiter faces more only where color (rather than shape) had been manipulated. Results are discussed in terms of the broader relations around ethnicity, status, and technological transition in this area.

Transfer Learning with EfficientNetV2S for Automatic Face Shape Classification

The classification of human face shapes, a pivotal aspect of one&amp;rsquo;s appearance, plays a crucial role in diverse fields like beauty, cosmetics, healthcare, and security. In this paper, we present a multi-step methodology for face shape classification, harnessing the potential of transfer learning and a pretrained EfficientNetV2S neural network. Our approach comprises key phases, including preprocessing, augmentation, training, and testing, ensuring a comprehensive and reliable solution. The preprocessing step involves precise face detection, cropping, and image scaling, laying a solid foundation for accurate feature extraction. Our methodology utilizes a publicly available dataset of female celebrities, comprising five face shape classes: heart, oblong, oval, round, and square. By augmenting this dataset during training, we magnify its diversity, enabling better generalization and enhancing the model&amp;rsquo;s robustness. With the EfficientNetV2S neural network, we employ transfer learning, leveraging pretrained weights to optimize accuracy, training speed, and parameter size. The result is a highly efficient and effective model, which outperforms state-of-the-art approaches on the same dataset, boasting an outstanding overall accuracy of 96.32%. Our findings demonstrate the efficiency of our approach, proving its potential in the field of face shape classification. The success of our methodology holds promise for various applications, offering valuable insights into beauty analysis, cosmetic recommendations, and personalized healthcare.

Study on the fit of nonwoven face masks on different face shapes

In the midst of the global COVID-19 pandemic, airborne infectious diseases, including contagious tuberculosis and illnesses transmitted through airborne droplets, such as influenza, SARS, and avian influenza, have emerged as some of the most severe pandemics in human history. Face masks have become an essential everyday item, despite their previous use primarily for the sick. Current mask designs come in various sizes; however, they may not be suitable for all face shapes, particularly for individuals with smaller or frequently moving facial features. Therefore, there is a need for research, especially focusing on women and individuals with smaller faces, to enhance the effectiveness of face masks in providing adequate protection. Accordingly, this study examined the current typical mask design ‘normal mask’ and four proposed mask designs for five face shapes (round, diamond, oval, square, or oblong) by using a quantitative fit test, as suggested in ISO 16975-3 and OSHA 29 CFR1910.134, to determine the masks’ fit factor (FF). The FF of the normal mask was 80% on round faces, 66% on diamond faces, but only 41% on square and oblong faces. The FaceMe artificial intelligence program was used to modify the face mask design in accordance with each face shape, and the level of air leakage was evaluated. The results showed that modifying the mask edges could reduce air leakage, especially during movements. For square faces, the leakage level was reduced from 63% (normal mask) to 38% (line mask). For oblong faces, the normal mask had a leakage level of 63%, whereas wave masks reduced leaking to 34%, resulting in a reduction of almost 30%. Mask fit could also be improved by adjusting earloop tightness.

Dosage-dependent effects of FGFR2W290R mutation on craniofacial shape and cellular dynamics of the basicranial synchondroses.

Craniosynostosis is a common yet complex birth defect, characterized by premature fusion of the cranial sutures that can be syndromic or nonsyndromic. With over 180 syndromic associations, reaching genetic diagnoses and understanding variations in underlying cellular mechanisms remains a challenge. Variants of FGFR2 are highly associated with craniosynostosis and warrant further investigation. Using the missense mutation FGFR2W290R , an effective mouse model of Crouzon syndrome, craniofacial features were analyzed using geometric morphometrics across developmental time (E10.5-adulthood, n = 665 total). Given the interrelationship between the cranial vault and basicranium in craniosynostosis patients, the basicranium and synchondroses were analyzed in perinates. Embryonic time points showed minimal significant shape differences. However, hetero- and homozygous mutant perinates and adults showed significant differences in shape and size of the cranial vault, face, and basicranium, which were associated with cranial doming and shortening of the basicranium and skull. Although there were also significant shape and size differences associated with the basicranial bones and clear reductions in basicranial ossification in cleared whole-mount samples, there were no significant alterations in chondrocyte cell shape, size, or orientation along the spheno-occipital synchondrosis. Finally, shape differences in the cranial vault and basicranium were interrelated at perinatal stages. These results point toward the possibility that facial shape phenotypes in craniosynostosis may result in part from pleiotropic effects of the causative mutations rather than only from the secondary consequences of the sutural defects, indicating a novel direction of research that may shed light on the etiology of the broad changes in craniofacial morphology observed in craniosynostosis syndromes.

Fetal face shape analysis from prenatal 3D ultrasound images

3D ultrasound imaging of fetal faces has been predominantly confined to qualitative assessment. Many genetic conditions evade diagnosis and identification could assist with parental counselling, pregnancy management and neonatal care planning. We describe a methodology to build a shape model of the third trimester fetal face from 3D ultrasound and show how it can objectively describe morphological features and gestational-age related changes of normal fetal faces. 135 fetal face 3D ultrasound volumes (117 appropriately grown, 18 growth-restricted) of 24-34 weeks gestation were included. A 3D surface model of each face was obtained using a semi-automatic segmentation workflow. Size normalisation and rescaling was performed using a growth model giving the average size at every gestation. The model demonstrated a similar growth rate to standard head circumference reference charts. A landmark-free morphometry model was estimated to characterize shape differences using non-linear deformations of an idealized template face. Advancing gestation is associated with widening/fullness of the cheeks, contraction of the chin and deepening of the eyes. Fetal growth restriction is associated with a smaller average facial size but no morphological differences. This model may eventually be used as a reference to assist in the prenatal diagnosis of congenital anomalies with characteristic facial dysmorphisms.

Face shape and motion are perceptually separable: Support for a revised model of face processing.

A recent model of face processing proposes that face shape and motion are processed in parallel brain pathways. Although tested in neuroimaging, the assumptions of this theory remain relatively untested through controlled psychophysical studies until now. Recruiting undergraduate students over the age of 18, we test this hypothesis using a tight control of stimulus factors, through computerized three-dimensional face models and calibration of dimensional discriminability, and of decisional factors, through a model-based analysis using general recognition theory (GRT). Theoretical links between neural and perceptual forms of independence within GRT allowed us to derive the a priori hypotheses that perceptual separability of shape and motion should hold, while other forms of independence defined within GRT might fail. We found evidence to support both of those predictions.

Editorial

Dear Readers,&amp;nbsp; It gives me great pleasure to announce the second regular issue of 2024. I would like to thank all the authors for their sound research and the editorial board for the extremely valuable reviews and suggestions for improvement. These contributions together with the generous support of the consortium members enable us to run our journal and maintain its quality.&amp;nbsp; I would still like to expand our editorial board: If you are a tenured associate professor or above with a good publication record, please apply to join our editorial board. We are also interested in high-quality proposals for special issues on new topics and emerging trends. And finally, we are still looking for some financial support for 2024 to cover all our expenses. We would be very grateful if your library or institution can support us. We would then be happy to add it to our consortium list.&amp;nbsp; In this regular issue, I am very pleased to present 6 accepted papers by 19 authors from 9 countries: Canada, China, Croatia, India, Kazakhstan, M&amp;eacute;xico, Sri Lanka, Ukraine, and Vietnam.&amp;nbsp; Petra Grd, Igor Tomi&amp;#269;i&amp;#263;, and Ena Bar&amp;#269;i&amp;#263; from Croatia address in their article a multi-step methodology for face shape classification that is based on the potential of transfer learning and a pretrained EfficientNetV2S neural network.&amp;nbsp; Lizbeth Alejandra Hern&amp;aacute;ndez-Gonz&amp;aacute;lez, Ulises Ju&amp;aacute;rez-Mart&amp;iacute;nez, Jezreel Mej&amp;iacute;a, and Alberto Aguilar-Laserre from M&amp;eacute;xico focus their research on applying the naturalistic programming paradigm within a software development process using a naturalistic software development method.&amp;nbsp; In a joint research, Shanshan Jia from China, Gaukhar A. Kamalova from the Republic of Kazakhstan, and Dmytro Mykhalevskiy from Ukraine report on a mobile handover technique aligning with the neighbour discovery paradigm in 6LoWPAN.&amp;nbsp; Ajay Kumar from India is investigating a mechanism to assess machine learning approaches for software effort estimation (SEE) modeling in the context of accuracy measures, specifically exploring machine learning techniques for SEE modeling as a multi-criteria decision making (MCDM) problem.&amp;nbsp; Anne Perera and Amitha Caldera from Sri Lanka conduct a comprehensive review on sentiment analysis in the context of mix of languages, phonetic typing and lexical borrowing in web communication.&amp;nbsp; And last but not least, in a collaboration between researchers from Vietnam and Canada, Tien Quang Dam, Nghia Thinh Nguyen, Trung Viet Le, Tran Duc Le, Sylvestre Uwizeyemungu, and Thang Le-Dinh look into malware detection methods, specifically leveraging machine learning to encode critical information from portable executable (PE) headers into visual representations of ransomware samples.&amp;nbsp; Enjoy Reading!&amp;nbsp; Cordially,&amp;nbsp; Christian G&amp;uuml;tl, Managing Editor-in-Chief Graz University of Technology, Graz, Austria

Face anthropometry for filtering facepiece respirators: analysis of the association between facial dimensions and respirator fit.

Ensuring proper respirator fit for individuals remains a persistent challenge in occupational environments, yet there is limited knowledge about how respirators interact with the face to "'fit." Previous studies have attempted to understand the association between face dimensions and respirator fit using traditional head/face anthropometry not specifically tailored for respirators. The purpose of this study was to assess and compare the ability of filtering facepiece respirator (FFR)-specific face anthropometry with traditional head/face anthropometry in exploring the relationship between facial dimensions and the fit of FFR. The study utilized 3D face scans and quantitative fit factor scores from 56 participants to investigate the relationship between face anthropometry and FFR fit. Both FFR-specific and traditional anthropometric measurements were obtained through 3D anthropometric software. Intra-correlation of anthropometry was analyzed to evaluate the efficiency and effectiveness of FFR-specific and traditional anthropometry respectively. Principal component analysis (PCA) was conducted to test the usefulness of the PCA method for investigating various facial features. Logistic regression was used to develop fit association models by estimating the relationship between each face measurement set and the binary outcome of the fit test result. The prediction accuracy of the developed regression models was tested. FFR-specific face anthropometry consists of a set of measurements that can inform the detailed facial shape associated with the FFRs more effectively than traditional head/face anthropometry. While PCA may have been effective in reducing the variable dimensions for the relatively large parts of the human body such as upper and lower bodies in previous literature, PCA results of FFR-specific and traditional anthropometry were inconsistent and insufficient to describe face dimensions with complex anatomy in a small-detailed area, suggesting that facial shape should be understood through a variety of approaches including statistical methods. Logistic regression analysis results confirmed that the association models of FFR-specific face anthropometry were significant with higher prediction accuracy and had a better model's goodness of fit than those of traditional head/face anthropometry in 3 conditions inputting all measurements, all PC scores, or top 5 measurements from PCA. The findings showed that the FFR fit association model enables an understanding of the detailed association between face and respirator fit and allows for the development of a system to predict respirator fit success or failure based on facial dimensions. Future research would include testing the validity of the model and FFR-specific measurement set on different respirator types, expanding the population set, and developing an integrated approach using automated and machine learning technologies to inform FFR selection for occupation workers and the general population.

A Review of Aesthetic Considerations for Treating the Transgender Patient.

As gender diversity becomes increasingly embraced by society, and despite growing recognition of the unique needs of transgender patients, the literature remains devoid of guidelines for gender affirming facial feminization or masculinization techniques. The authors seek to identify and discuss target feminine and masculine facial features, as well as an armamentarium of surgical and nonsurgical strategies to effectively address and achieve them in the transgender population. A search of the National Library of Medicine database (PubMed) was undertaken to identify the existing literature on gender-affirming facial feminization and masculinization techniques. The importance of assessing proportional relationships between the bitemporal, bizygomatic, and bigonial distances is discussed; ideal masculine faces possess a rectangular face shape, with ratios for these 3 areas tending toward 1:1:1. Conversely, the ideal female face is heart shaped with projection at the zygoma and a tapered jawline. Strategic positioning of the cheek apex serves as an anchor in sculpting a distinctly masculine or feminine face. Other considerations include the enhancement of skin quality and implications of hormonal therapy. The aesthetic considerations provided in this study can serve as a valuable guidance for aesthetic physicians seeking to deliver optimal care for their transitioning patients.

Assessing the Roles of Symmetry, Prototypicality, and Sexual Dimorphism of face Shape in Health Perceptions

Health perceptions are thought to play an important role in human mate preferences. Although many studies have investigated potential relationships between health ratings of faces and facial symmetry, prototypicality, and sexual dimorphism, findings have been mixed across studies. Consequently, we tested for potential relationships between health ratings of faces and the symmetry, prototypicality, and sexual dimorphism of those faces’ shapes. When these three shape characteristics were considered in separate regression models, we observed significant positive relationships between health ratings and both shape symmetry and prototypicality. By contrast, health ratings and sexual dimorphism were not significantly correlated in these analyses. However, in analyses in which symmetry, prototypicality, and sexual dimorphism were entered simultaneously as predictors in a single model, prototypicality, but not symmetry, was significantly correlated with health ratings. Moreover, sexual dimorphism predicted health ratings of female, but not male, faces in these analyses. Collectively, these results suggest that the relationship between symmetry and health ratings is, at least partly, driven by the effect of prototypicality on health perceptions and highlight the importance of considering multiple aspects of face shape when investigating factors that predict perceived health.