Are Neoclassical Canons Valid for Southern Chinese Faces?

Background

Proportions derived from neoclassical canons, initially described by Renaissance sculptors and painters, are still being employed as aesthetic guidelines during the clinical assessment of the facial morphology.

Objective

1. to determine the applicability of neoclassical canons for Southern Chinese faces and 2. to explore gender differences in relation to the applicability of the neoclassical canons and their variants.

Methodology

3-D photographs acquired from 103 young adults (51 males and 52 females) without facial dysmorphology were used to test applicability of four neoclassical canons. Standard anthropometric measurements that determine the facial canons were made on these 3-D images. The validity of the canons as well as their different variants were quantified.

Principal Findings

The neoclassical cannons seldom applied to these individuals, and facial three-section and orbital canons did not apply at all. The orbitonasal canon was most frequently applicable, with a frequency of 19%. Significant sexual dimorphism was found relative to the prevalence of the variants of facial three-section and orbitonasal canons.

Conclusion

The neoclassical canons did not appear to apply to our sample when rigorous quantitative measurements were employed. Thus, they should not be used as esthetic goals for craniofacial surgical interventions.     

Measurement and study of the nose and face and their correlations in the young adult of Han nationality

The measurement of 13 items in the face and nose of 220 young adults (110 males and 110 females) of the Han nationality between the ages of 18 and 21 years has been done in the Henan Province of China. The means and standard deviations have been obtained, and the significant differences in many items between males and females have been proved. Some items influencing outer nasal shape have been analyzed. The correlations between nose height, nose length, and morphologic facial height and physiognomic facial height have been discussed. The ratio and amount of nasal breadth to facial breadth and nasal breadth to interocular breadth have been compared and analyzed, and the differences among the different races and between the sexes have been explained.     

不同垂直骨面型错合畸形患者颈椎姿势差异的研究

目的:研究不同垂直骨面型错合畸形患者颈椎姿势的特点及差异,为正畸矫治错合畸形获得较好的临床效果及颅面、颈部生长发育的研究提供一定的参考依据。方法:采用计算机辅助X线头影测量技术,对226例不同垂直骨面型的儿童、成人在自然头位时拍摄的头颅定位侧位片进行测量研究,分别比较儿童以及成人不同垂直骨面型间颈椎姿势的差异。结果:儿童:CVT-OPT、SN-CP、SN-OPT及SN-CVT在低、均、高角各组间的差别均无统计学意义。成人:CVT-OPT在低角组与高角组间、均角组与高角组间的差别有统计学意义,高角组低于低角组和均角组,在低角组与均角组间的差别无统计学意义;SN-CP在低、均、高角各组间的差别有统计学意义,低角组<均角组<高角组;SN-OPT及SN-CVT在低角组与高角组间的差别有统计学意义,低角组<高角组,在低角组与均角组间、均角组与高角组间的差别无统计学意义。结论:不同垂直骨面型错合畸形患者的颈椎姿势在儿童无显著差异,在成人差异显著。     

不同垂直骨面型错合畸形患者颈椎姿势差异的研究

目的：研究不同垂直骨面型错合畸形患者颈椎姿势的特点及差异,为正畸矫治错合畸形获得较好的临床效果及颅面、颈部生长发育的研究提供一定的参考依据。方法：采用计算机辅助X线头影测量技术,对226例不同垂直骨面型的儿童、成人在自然头位时拍摄的头颅定位侧位片进行测量研究,分别比较儿童以及成人不同垂直骨面型间颈椎姿势的差异。结果：儿童：CVT-OPT、SN-CP、SN-OPT及SN-CVT在低、均、高角各组间的差别均无统计学意义。成人：CVT-OPT在低角组与高角组间、均角组与高角组间的差别有统计学意义,高角组低于低角组和均角组,在低角组与均角组间的差别无统计学意义;SN-CP在低、均、高角各组间的差别有统计学意义,低角组〈均角组〈高角组;SN-OPT及SN-CVT在低角组与高角组间的差别有统计学意义,低角组〈高角组,在低角组与均角组间、均角组与高角组间的差别无统计学意义。结论：不同垂直骨面型错合畸形患者的颈椎姿势在儿童无显著差异,在成人差异显著。     

Clinical anthropometry and canons of the face in historical perspective

Measurements of the human face as part of the body have been performed since the Greek era, and many aspects of ancient measurements can be found in modern clinical anthropometry. A historical appraisal of the use of facial measurements is presented. The influence on modern facial anthropometry of Greek proportion sciences, the golden proportion, canons of important Renaissance artists, physical anthropology, and cephalometry are discussed. The main difference between human measurements in classic times and modern anthropometry is the denial of realistic sizes and proportions in former times. Human forms and canons were depicted in a way the artist or scientist preferred, rather than how they objectively were. For reconstructive and cosmetic surgery, realistic sizes and proportions are assessed using anthropometric techniques and used as guidelines to correct deformities or disproportions.     

Selectivity of Face Perception to Horizontal Information over Lifespan (from 6 to 74 Year Old)

Face recognition in young human adults preferentially relies on the processing of horizontally-oriented visual information. We addressed whether the horizontal tuning of face perception is modulated by the extensive experience humans acquire with faces over the lifespan, or whether it reflects an invariable processing bias for this visual category. We tested 296 subjects aged from 6 to 74 years in a face matching task. Stimuli were upright and inverted faces filtered to preserve information in the horizontal or vertical orientation, or both (HV) ranges. The reliance on face-specific processing was inferred based on the face inversion effect (FIE). FIE size increased linearly until young adulthood in the horizontal but not the vertical orientation range of face information. These findings indicate that the protracted specialization of the face processing system relies on the extensive experience humans acquire at encoding the horizontal information conveyed by upright faces.     

Craniofacial changes in hemifacial microsomia

Cephalometry, X-ray cephalometry, and somatoscopy were used in the studies of 65 adult males with a severe unilateral microtia subdivided into three groups: with marked asymmetry, with slight asymmetry, and without any obvious facial asymmetry. The group with marked asymmetries was designated as hemifacial microsomia. In this group the affected side of the face was depressed on the average from above and from below towards the level of the external auditory canal. The center of the anteroposterior reduction was situated in the region in front of the pterygomaxillar fissure. The anteroposterior and vertical facial dimensions on the affected side were reduced most markedly, while the width dimensions showed the slightest changes. Hypoplasia was most severe within the lower face and increased towards the otocephalic centre. The mandibular joint was displaced in an anteroinferior and medial direction. Hypertelorism did not occur, but the orbit on the affected side was smaller in height and was frequently vertically dislocated. The facial profile was unchanged except for retrusion of the chin and increased frequency of bite disorders. The mobility of the mandible was limited. Hemihypoplasia also exerted an influence on structures that were not of branchiogenic origin, e.g., the cranial base (narrowing, asymmetry, and more pronounced curvature), the neurocranium (depression in mastoid and tympanotemporal regions, posterior rotation of the vault), and the frontonasal component (deviation of the nose and premaxilla). The cranial vault and the bottom of the occipital bone showed on the average no asymmetries. The similar character of deviations in slightly affected groups revealed that in spite of the high variability of changes typical for branchiogenic malformations the development of the face in these defects was subjected to certain rules. Marked facial asymmetry occurred only in every fifth patient with a severe degree of microtia, while definite signs of asymmetry were absent in every third patient.     

Facialmetric similarities mediate mate choice: sexual imprinting on opposite-sex parents

Former studies have suggested that imprinting-like processes influence the shaping of human mate preferences. In this study, we provide more direct evidence for assessing facial resemblance between subjects' partner and subjects' parents. Fourteen facial proportions were measured on 312 adults belonging to 52 families, and the correlations between family members were compared with those of pairs randomly selected from the population. Spouses proved to be assortatively mated in the majority of measured facial proportions. Significant correlations have been found between the young men and their partner's father (but not his mother), especially on facial proportions belonging to the central area of the face. Women also showed resemblance to their partner's mother (but not to their father) in the facial characteristics of their lower face. Replicating our previous studies, facial photographs of participants were also matched by independent judges who ascribed higher resemblance between partners, and subjects and their partners' opposite-sex parents, compared with controls. Our results support the sexual imprinting hypothesis which states that children shape a mental template of their opposite-sex parents and search for a partner who resembles that perceptual schema. The fact that only the facial metrics of opposite-sex parents showed resemblance to the partner's face tends to rule out the role of familiarity in shaping mating preferences. Our findings also reject several other rival hypotheses. The adaptive value of imprinting-related human mating is discussed, and a hypothesis is made of why different facial areas are involved in males' and females' search for resemblance.     

Facial heights: evolutionary relevance of postnatal ontogeny for facial orientation and skull morphology in humans and chimpanzees

Facial heights, i.e. the vertical distances between the superior and inferior limits of facial compartments, contribute to the orientation of the viscerocranium in the primate skull. In humans, vertical facial variation is among the main sources of diversity and frequently associated with an integrated suite of other cranio-mandibular traits. Facial heights and kyphosis are also important factors in interspecific variation and models of hominoid evolution. The ontogenetic determination of adult facial orientation and its relation to phylogenetic variation are unclear, but crucial in all previously mentioned respects. We addressed these issues in a sample of 175 humans and chimpanzees with Procrustes based geometric morphometrics, testing hypotheses of interspecific similarity in postnatal ontogenetic trajectories, early versus later ontogenetic facial pattern determination, and a developmental model of morphological integration. We analyzed the contribution of postnatal morphogenesis to adult vertical facial variation by partitioning morphological variation into a portion of pure growth allometry and a non-allometric fraction. A statistically significant difference of growth-allometries revealed that in both species growth established the adult skull proportions by vertical facial expansion, but while in chimpanzees the complete viscerocranium showed reorientation, in humans only the lower face was modified. In both species the results support a hypothesis of early facial pattern determination. A coincident emergence of morphological traits favors a hypothesis of developmental integration of the face, excluding traits of the basi- and neurocranium. Interspecific differences in integration may have implications for evolutionary studies. The present findings indicate that growth establishes the adult skull proportions and integrates principal facial orientation patterns, already there in early postnatal ontogeny.     

Surface facial modelling and allometry in relation to sexual dimorphism

Sexual dimorphism is responsible for a substantial part of human facial variability, the study of which is essential for many scientific fields ranging from evolution to special biomedical topics. Our aim was to analyse the relationship between size variability and shape facial variability of sexual traits in the young adult Central European population and to construct average surface models of adult males and females. The method of geometric morphometrics allowed not only the identification of dimorphic traits, but also the evaluation of static allometry and the visualisation of sexual facial differences.Facial variability in the studied sample was characterised by a strong relationship between facial size and shape of sexual dimorphic traits. Large size of face was associated with facial elongation and vice versa. Regarding shape sexual dimorphic traits, a wide, vaulted and high forehead in combination with a narrow and gracile lower face were typical for females. Variability in shape dimorphic traits was smaller in females compared to males. For female classification, shape sexual dimorphic traits are more important, while for males the stronger association is with face size.Males generally had a closer inter-orbital distance and a deeper position of the eyes in relation to the facial plane, a larger and wider straight nose and nostrils, and more massive lower face. Using pseudo-colour maps to provide a detailed schematic representation of the geometrical differences between the sexes, we attempted to clarify the reasons underlying the development of such differences.     

Anthropometric analysis of the face in hypohidrotic ectodermal dysplasia: a family study

Sixteen individuals with hypohidrotic ectodermal dysplasia (HED) were compared to normal standards as well as to 16 unaffected family members by using a series of 20 anthropometric measurements of the head and face. Individuals with HED were generally smaller than normal controls or their unaffected relatives. However, this size reduction was not uniform. Instead, it was most evident in the anterior-posterior dimensions of the lower two-thirds of the face, in facial height, and in the size of the ears, nose, and mouth. A stepwise discriminant function analysis indicated that a function constructed from four variables (depth of the lower face, width of the nose, mandibular arc, and total facial height) could accurately classify 96.7% of the 32 individuals in the combined sample of affected and unaffected individuals. These findings demonstrated that the face of individuals with HED is unique and can be useful in its diagnosis. Additional studies are needed to determine if similar-though-less-pronounced facial abnormalities can be used to detect minimally affected gene carriers of this presumably X-linked condition.     

Denture Wearers' Awareness of their Vertical Dimension

A method of analyzing facial proportions in evaluating occlusal vertical dimension was used in a test on 71 complete denture wearers aiming to find a way to rank denture wearers with different stages of reduced vertical dimension and development an instruction for patients' self judgment. By use of face drawings on a proforma the patients ranked themselves into one of four classes. The investigator also ranked the patients into these classes. There was a significant correlation (p<0.01) between the ranking by patient and investigator. The face proportions were also measured with an instrument. The distances nasion-rima oris and subnasale-gnathion were established. When ranking into classes, there was a significant (p<0.0001) correlation between the ranking by the investigator and the measurements. The results show that it may be possible to use information of facial proportions to give complete denture wearers a way of assessment of face height and thus a reason to consult a dentist in case of suspicion of reduced vertical dimension.     

Testing the Utility of a Data-Driven Approach for Assessing BMI from Face Images

Several lines of evidence suggest that facial cues of adiposity may be important for human social interaction. However, tests for quantifiable cues of body mass index (BMI) in the face have examined only a small number of facial proportions and these proportions were found to have relatively low predictive power. Here we employed a data-driven approach in which statistical models were built using principal components (PCs) derived from objectively defined shape and color characteristics in face images. The predictive power of these models was then compared with models based on previously studied facial proportions (perimeter-to-area ratio, width-to-height ratio, and cheek-to-jaw width). Models based on 2D shape-only PCs, color-only PCs, and 2D shape and color PCs combined each performed significantly and substantially better than models based on one or more of the previously studied facial proportions. A non-linear PC model considering both 2D shape and color PCs was the best predictor of BMI. These results highlight the utility of a “bottom-up”, data-driven approach for assessing BMI from face images.     

Cephalometric study of elderly with nearly intact dental arches

Objective: The purpose of this study was to investigate the craniofacial morphology of elderly people with many remaining teeth using cephalometric analysis. Subjects and methods: The subjects were 30 Japanese elderly who participated in the ‘8020 campaign 2001’ in Bunkyo Ward, Tokyo, organised by The Dental Association of Tokyo, as well as 30 Japanese young adults with normal occlusion. Lateral cephalograms of all subjects were analysed using the Coben method. Results: In the female elderly group, the lower face depth was smaller than in the younger adults. In the male elderly group, the height and depth of both the total face and the lower face were longer than in the younger group. In comparing the 8020 achievers with the younger group, the proportion of the lower facial height was greater than the upper facial height, and this finding was more pronounced in women than in men. Conclusion: For the lateral facial pattern of the elderly, a reduction of lower facial height because of tooth occlusal reduction was not apparent. It was clear that there are age differences for males and females; in addition, differences in the total face and lower face area of the elderly group were due to their having many remaining teeth over a long time period. Also, these changes were more apparent in women than in men, and it is clear that there is a male–female difference in ageing.     

Craniofacial anthropometric pattern profile in hypohidrotic ectodermal dysplasia--application in detection of gene carriers

Hypohidrotic ectodermal dysplasia (HED) is characterized by clinical manifestations of severe hypodontia or anodontia, hypotrichosis, hypohidrosis, and specific facial appearance. Affected males show complete expression of clinical features of this condition. Their mothers, who are gene carriers, express only some signs, which are usually very mild. Currently available clinical methods are not sufficient for routine identification of the HED heterozygous gene carriers. The purpose of this study was to identify and describe the facial characteristics of HED patients and their mothers and to evaluate the usefulness of craniofacial pattern profile analysis (CFPP) in the diagnosis of this syndrome and the detection of gene carriers. In this study six affected males and their mothers were evaluated. Z-scores for each variable were calculated and compared with age- and sex-matched controls. Anthropometric analysis showed a specific dysmorphic pattern in CST patients that includes decreased skull base width (t-t: -1.67 Z); decreased forehead width (ft-ft: -1.8 Z), decreased midface depth (sn-t: -2.02 Z), markedly decreased total facial height (n-gn: -3.4 Z), and markedly decreased maxillary arc (t-sn-t: -2.5 Z). Gene carriers showed a similar tendency in their pattern profiles. They showed the same tendency towards lower Z-values for forehead width, facial height, and mouth width. The values for these measurements were between those of the affected and healthy controls. The most pronounced findings were increased head width (eu-eu: +2.83 Z), increased lower face width (go-go: +2.06 Z), and reduction of total facial height (n-gn: -0.95 Z). They also displayed increased nose width (al-al: +2.41 Z) and increased biocular distance (ex-ex: +2.01 Z). When used in conjunction with other methods the anthropometrics pattern profile analysis can considerably enhance detection of gene carriers for HED and increase objective assessment of the craniofacial region in HED patients.     

Absence of correlation between Y chromosome heterochromatin and several anthropometric measurements in a Mexican population

Summary The correlation between nine anthropometric variables and six different measurements of the Y heterochromatic regions of 146 young Mexican adults was investigated. Only the absolute heterochromatic width showed a significant correlation at the 0.02 level with the upper segment/lower segment ratio, but the biological significance of this finding is strongly questioned.     

Denture Wearer's Self Assessment of Vertical Dimension

Two groups of complete denture wearers were used. They were informed about normal facial proportions and were then asked to classify themselves into one of four face height classes. One group had to choose between four schematic drawings and the other between four color photos of a complete denture wearer, taken at different vertical dimensions. The patients' self-assessment was correlated to a professional assessment and measurements of the patients' face. The patients' assessments were significantly correlated to the professional assessment in both groups. Self assessment of facial proportions by complete denture wearers could be an easy and useful method of activating them to consult a dentist for check-up. The simple drawings were found to be most suitable.     

Comparison of whole-body vertical stiffness and leg stiffness during single-leg hopping in place in children and adults

In the hopping literature, whole-body vertical stiffness and leg stiffness are used interchangeably, due to most of the movement occurring in the vertical direction. However, there is some anterior/posterior movement of the center of mass and displacements of the foot during hopping in place in both children and adults. Further it is not understood if leg stiffness show a similar pattern as whole-body vertical stiffness when increasing hopping frequency. The purpose of this study was to test if whole-body vertical stiffness and leg stiffness are different during single-leg hopping in-place in children and adults, across a range of frequencies. Seventeen children aged 5–11 years and 16 young adults participated in this study. The subjects hopped at their preferred frequency as well as 20% below, 20% above and 40% above preferred frequency. Our results demonstrate that both whole-body vertical stiffness and leg stiffness increase when increasing hopping frequency for children and adults. However, whole-body vertical stiffness consistently overestimates leg stiffness due to a similar peak force but a greater leg length change compared to vertical COM displacement. This suggests a considerable horizontal COM movement from landing to mid-stance during hopping. Children aged 5–11 years old showed lower absolute values but higher normalized values of two stiffness measures than adults. This suggests somewhat adult-like stiffness control in children, but a reduced ability to manipulate the horizontal movement during single-leg hopping in place when compared to adults.     

Does My Face FIT?: A Face Image Task Reveals Structure and Distortions of Facial Feature Representation

Despite extensive research on face perception, few studies have investigated individuals’ knowledge about the physical features of their own face. In this study, 50 participants indicated the location of key features of their own face, relative to an anchor point corresponding to the tip of the nose, and the results were compared to the true location of the same individual’s features from a standardised photograph. Horizontal and vertical errors were analysed separately. An overall bias to underestimate vertical distances revealed a distorted face representation, with reduced face height. Factor analyses were used to identify separable subconfigurations of facial features with correlated localisation errors. Independent representations of upper and lower facial features emerged from the data pattern. The major source of variation across individuals was in representation of face shape, with a spectrum from tall/thin to short/wide representation. Visual identification of one’s own face is excellent, and facial features are routinely used for establishing personal identity. However, our results show that spatial knowledge of one’s own face is remarkably poor, suggesting that face representation may not contribute strongly to self-awareness.     

Biological arches and changes to the curvilinear form of the aging maxilla

The facial skeleton can be conceptualized as a series of arches aligned along a vertical axis, with regional differences in shape. Previous work suggested that the maxilla undergoes differential growth with time. Because these arch forms resemble geometric forms, it may be possible to measure changes to their shape with the aging process. A contour analysis of the aging maxilla was undertaken. Computed tomographic data were assembled retrospectively. Only men were studied, and they were divided into two groups: young (aged 18 to 24 years; n = 6) and old (aged 40 to 66 years; n = 6). The computed tomography data were reconstructed into three-dimensional images and underwent standardization for comparison purposes. An axial view of the maxilla along the Frankfort horizontal was used for analysis. To quantify changes between curves, measurements were made of the vertical distance from eight equidistant points along each curve perimeter to a standardized baseline. Average arch forms for young and old men were then generated for comparison purposes. Each of the eight points along the older maxillary arch form existed further from the baseline than the younger arch form. This difference reached statistical significance at three of the eight points measured along the two curves. The greatest difference occurred at point 8 (p = .0006), which was at the medial maxilla near the nasomaxillary junction. The results of the study suggest that the actual contour of the maxilla undergoes changes as a result of the aging process. Mathematically defined idealized skeletal contours could help guide reconstructive surgery and aesthetic augmentation of the facial skeleton in the future. In addition, certain soft tissues of the face and torso seem to share a common shape (an alpha contour). This shape may also exhibit idealized forms open to quantitative analysis. The skeletal arch form and alpha contour most likely exhibit sexual dimorphism and will require further investigation. The ubiquity of the arch form in nature and possible implications for growth and development of the human facial skeleton are also discussed.