scholarly journals Heritability of face shape in twins: a preliminary study using 3D stereophotogrammetry and geometric morphometrics

2013 ◽  
Vol 1 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Seth M. Weinberg ◽  
Trish E. Parsons ◽  
Mary L. Marazita ◽  
Brion S. Maher
Keyword(s):  
Principal Components ◽  
Facial Morphology ◽  
Narrow Sense Heritability ◽  
Geometric Morphometric ◽  
Face Shape ◽  
Facial Shape ◽  
High Heritability ◽  
3D Photogrammetry ◽  
The Individual ◽  
Biological Shape

Introduction: Previous research suggests that aspects of facial surface morphology are heritable.  Traditionally, heritability studies have used a limited set of linear distances to quantify facial morphology and often employ statistical methods poorly designed to deal with biological shape.  In this preliminary report, we use a combination of 3D photogrammetry and landmark-based morphometrics to explore which aspects of face shape show the strongest evidence of heritability in a sample of twins. Methods: 3D surface images were obtained from 21 twin pairs (10 monozygotic, 11 same-sex dizygotic).  Thirteen 3D landmarks were collected from each facial surface and their coordinates subjected to geometric morphometric analysis.  This involved superimposing the individual landmark configurations and then subjecting the resulting shape coordinates to a principal components analysis.  The resulting PC scores were then used to calculate rough narrow-sense heritability estimates. Results: Three principal components displayed evidence of moderate to high heritability and were associated with variation in the breadth of orbital and nasal structures, upper lip height and projection, and the vertical and forward projection of the root of the nose due to variation in the position of nasion. Conclusions: Aspects of facial shape, primarily related to variation in length and breadth of central midfacial structures, were shown to demonstrate evidence of strong heritability. An improved understanding of which facial features are under strong genetic control is an important step in the identification of specific genes that underlie normal facial variation.

scholarly journals Examination of Facial Shape Changes Associated with Cardiovascular Disease Using Geometric Morphometrics

2018 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Cardiovascular Disease ◽  
Cardiovascular Diseases ◽  
Geometric Morphometrics ◽  
Directional Asymmetry ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Facial Shape ◽  
Normal Individuals ◽  
The Individual ◽  
Shape Changes

Facial investigations using geometric morphometrics has been used in many studies to affirm that a particular disease can attribute to an individual’s facial morphology. A landmark based geometric morphometric analysis was used in this study to asses if facial shape changes are associated with cardiovascular diseases (CVD) and if facial morphology of the CVD individuals differs from the normal ones. In the Municipality of Cantilan, Surigao del Sur, frontal face images taken from 32 cardiovascular disease patients and 32 normal individuals were examined using forty-one manually positioned landmarks. Result showed that facial morphology of the CVD group differs from non-CVD group. Procrustes ANOVA showed significant values for the individual symmetry and directional asymmetry. The analysis of structure by the Principal Components reveals particular variations and the scatter plot of the residual asymmetry shows distinct differences between CVD and non-CVD. Therefore, cardiovascular diseases contribute to facial shape changes and that development of facial morphology differs between CVD and non-CVD group.

scholarly journals Soft tissue facial changes among adult females during alignment stage of orthodontic treatment: a 3D geometric morphometric study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Si Yu Hou ◽  
Wenwen Zhou ◽  
Hongwei Dai ◽  
Hai Ming Wong ◽  
Yi Feng Wen ◽  
...  
Keyword(s):  
Orthodontic Treatment ◽  
Shape Change ◽  
Morphometric Study ◽  
Temporal Region ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Adult Females ◽  
Facial Shape ◽  
Facial Changes ◽  
Facial Form

Abstract Background To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment. Methods 43 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment. Results We observed statistically significant changes in facial shape across the three treatment stages (p = 0.0022). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0045) and from T0 to T2 (p = 0.0072). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.32 mm, 0.21 mm, and 1.34 mm, respectively. Changes in mean facial form were not statistically significant (p = 0.1143). No changes in variance of facial shape were observed across treatment stages (p > 0.05). Conclusion Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

Soft Tissue Facial Changes Among Adult Females Receiving Orthodontic Treatment: A Spatially Dense 3D Geometric Morphometric Study

2020 ◽  
Author(s):  
Si Yu Hou ◽  
Wenwen Zhou ◽  
Hongwei Dai ◽  
Hai Ming Wong ◽  
Yi Feng Wen ◽  
...  
Keyword(s):  
Orthodontic Treatment ◽  
Shape Change ◽  
Morphometric Study ◽  
Temporal Region ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Adult Females ◽  
Facial Shape ◽  
Mean And Variance ◽  
Facial Changes

Abstract Background: To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment.Methods: 18 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment.Results: We observed statistically significant changes in facial shape across the three treatment stages (p = 0.003). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0059) and from T0 to T2 (p = 0.0098). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.31 mm, 0.22 mm, and 1.33 mm, respectively. Changes in mean facial shape were not statistically significant (p = 0.103). No changes in variance of facial shape were observed across treatment stages (p > 0.05).Conclusion: Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

scholarly journals The relationship between facial morphology, body measurements and socio-economic factors

2016 ◽  
Vol 79 (2) ◽  
pp. 181-200 ◽  
Author(s):  
Marie Jandová ◽  
Petra Urbanová
Keyword(s):  
Shape Change ◽  
Living Conditions ◽  
Smoking Habits ◽  
Economic Factors ◽  
Facial Morphology ◽  
Body Measurements ◽  
Geometric Morphometric ◽  
Facial Shape ◽  
Shape Changes ◽  
Socio Economic Factors

Abstract Background and aim: The effect of socio-economic factors (living conditions) and parental smoking habits on development of facial morphology and body measurements was studied on a longitudinal Czech sample of 25 girls and 25 boys. Subjects and methods: A set of studied digitalized photographs taken from 0.5 to 18 years in intervals of 6 months originated in the Brno Longitudinal Study. Facial shape changes of sub-adult participants were described using a configuration of 27 landmarks and further studied by using methods of geometric morphometric and multivariate statistics. In order to localize growth-related shape changes within the face, the studied region was divided into upper, middle and lower facial units and analyzed separately. Results and conclusion: The results show that in the course of ontogenesis there is a strong correlation between facial shape change and body measurements, height included (r=0.10 and r=0.24 in boys and in girls, respectively). The pubertal spurt of the facial shape change rate was revealed at 10.5 years in girls and at 11.5 years in boys. The earlier onset of the pubertal rate increase in facial shape changes in boys was associated with records of poor living conditions. In addition, the mother’s smoking habits were linked to a noticeable facial shape change.

scholarly journals Soft tissue facial changes among adult females during the first six months of orthodontic treatment: a spatially dense 3D geometric morphometric study

2020 ◽  
Author(s):  
Si Yu Hou ◽  
Wenwen Zhou ◽  
Hongwei Dai ◽  
Hai Ming Wong ◽  
Yi Feng Wen ◽  
...  
Keyword(s):  
Orthodontic Treatment ◽  
Shape Change ◽  
Morphometric Study ◽  
Temporal Region ◽  
Facial Morphology ◽  
Geometric Morphometric ◽  
Adult Females ◽  
Facial Shape ◽  
Facial Changes ◽  
Facial Form

Abstract Background: To investigate changes in facial morphology during the first six months of orthodontic treatment among adult females receiving orthodontic treatment.Methods: 18 adult females receiving orthodontic treatment were randomly recruited. 3D facial images were taken at baseline (T0), three months (T1), and six months (T2) after treatment initiation. Spatially dense facial landmarks were digitized to allow for sufficient details in characterization of facial features. 3D geometric morphometrics and multivariate statistics were used to investigate changes in mean and variance of facial shape and facial form associated with treatment.Results: We observed statistically significant changes in facial shape across the three treatment stages (p = 0.003). Pairwise comparisons suggested significant changes from T0 to T1 (p = 0.0059) and from T0 to T2 (p = 0.0098). Heatmap visualization indicated that the buccal and temporal region were invaginated while the labial region became protruded with treatment. The magnitude of shape change was 0.009, 0.004, and 0.010 from T0 to T1, T1 to T2, and T0 to T2, respectively, in unit of Procrustes distance. The average magnitude of change per-landmark was 1.31 mm, 0.22 mm, and 1.33 mm, respectively. Changes in mean facial form were not statistically significant (p = 0.103). No changes in variance of facial shape were observed across treatment stages (p > 0.05).Conclusion: Rate of facial changes was twice as fast during the first three months as that during fourth to sixth month. Buccal and temporal region became invaginated while labial region became protruded with treatment.

scholarly journals Feed efficiency of lactating Holstein cows is less reproducible when changing dietary starch and fibre concentrations than within diet over subsequent lactation stages

2021 ◽  
Author(s):  
Amélie Fischer ◽  
Philippe Gasnier ◽  
Philippe Faverdin
Keyword(s):  
Principal Components ◽  
Feed Efficiency ◽  
Nir Spectroscopy ◽  
Principal Component ◽  
Holstein Cows ◽  
Diet Change ◽  
Total Variability ◽  
The One ◽  
The Individual ◽  
Starch Diet

ABSTRACTBackgroundImproving feed efficiency has become a common target for dairy farmers to meet the requirement of producing more milk with fewer resources. To improve feed efficiency, a prerequisite is to ensure that the cows identified as most or least efficient will remain as such, independently of diet composition. Therefore, the current research analysed the ability of lactating dairy cows to maintain their feed efficiency while changing the energy density of the diet by changing its concentration in starch and fibre. A total of 60 lactating Holstein cows, including 33 primiparous cows, were first fed a high starch diet (diet E+P+), then switched over to a low starch diet (diet E−P−). Near infra-red (NIR) spectroscopy was performed on each individual feed ingredient, diet and individual refusals to check for sorting behaviour. A principal component analysis (PCA) was performed to analyse if the variability in NIR spectra of the refusals was explained by the differences in feed efficiency.ResultsThe error of reproducibility of feed efficiency across diets was 2.95 MJ/d. This error was significantly larger than the errors of repeatability estimated within diet over two subsequent lactation stages, which were 2.01 MJ/d within diet E−P− and 2.40 MJ/d within diet E+P+. The coefficient of correlation of concordance (CCC) was 0.64 between feed efficiency estimated within diet E+P+ and feed efficiency estimated within diet E−P−. This CCC was smaller than the one observed for feed efficiency estimated within diet between two subsequent lactation stages (CCC = 0.72 within diet E+P+ and 0.85 within diet E−P−). The first two principal components of the PCA explained 90% of the total variability of the NIR spectra of the individual refusals. Feed efficiency was poorly correlated to those principal components, which suggests that feed sorting behaviour did not explain differences in feed efficiency.ConclusionsFeed efficiency was significantly less reproducible across diets than repeatable within the same diet over subsequent lactation stages, but cow’s ranking for feed efficiency was not significantly affected by diet change. The differences in sorting behaviour between cows were not associated to feed efficiency differences in this trial neither with the E+P+ diet nor with the E−P− diet. Those results have to be confirmed with cows fed with more extreme diets (for example roughage only) to ensure that the least and most efficient cows will not change.

scholarly journals Individual variation of the masticatory system dominates 3D skull shape in the herbivory-adapted marsupial wombats

2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  
Keyword(s):  
Individual Variation ◽  
Principal Component ◽  
Individual Variability ◽  
Shape Variation ◽  
Mandibular Ramus ◽  
Geometric Morphometric ◽  
Skull Shape ◽  
Marsupial Species ◽  
Masticatory System ◽  
The Individual

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.

scholarly journals The Association between Facial Morphology and Cold Pattern

2021 ◽  
Vol 42 (4) ◽  
pp. 113-129
Author(s):  
Ilkoo Ahn ◽  
Kwang-Ho Bae ◽  
Hee-Jeong Jin ◽  
Siwoo Lee
Keyword(s):  
Morphological Features ◽  
Facial Morphology ◽  
Sensory Organs ◽  
Negatively Associated ◽  
East Asian Medicine ◽  
Center Point ◽  
Facial Shape ◽  
Asian Medicine ◽  
The Face ◽  
Analysis System

Objectives: Facial diagnosis is an important part of clinical diagnosis in traditional East Asian Medicine. In this paper, using a fully automated facial shape analysis system, we show that facial morphological features are associated with cold pattern.Methods: The facial morphological features calculated from 68 facial landmarks included the angles, areas, and distances between the landmark points of each part of the face. Cold pattern severity was determined using a questionnaire and the cold pattern scores (CPS) were used for analysis. The association between facial features and CPS was calculated using Pearson's correlation coefficient and partial correlation coefficients.Results: The upper chin width and the lower chin width were negatively associated with CPS. The distance from the center point to the middle jaw and the distance from the center point to the lower jaw were negatively associated with CPS. The angle of the face outline near the ear and the angle of the chin line were positively associated with CPS. The area of the upper part of the face and the area of the face except the sensory organs were negatively associated with CPS. The number of facial morphological features that exhibited a statistically significant correlation with CPS was 37 (unadjusted).Conclusions: In this study of a Korean population, subjects with a high CPS had a more pointed chin, longer face, more angular jaw, higher eyes, and more upward corners of the mouth, and their facial sensory organs were relatively widespread.

scholarly journals On two species of Riocypris (Crustacea, Ostracoda) from northern Patagonia and their relation to Eucypris fontana: implications in paleoenvironmental reconstructions

2018 ◽  
Vol 96 (8) ◽  
pp. 801-817 ◽  
Author(s):  
C.A. Coviaga ◽  
A.P. Pérez ◽  
L.Y. Ramos ◽  
P. Alvear ◽  
G.C. Cusminsky
Keyword(s):  
Sexual Dimorphism ◽  
Morphometric Analysis ◽  
Indicator Species ◽  
Taxonomic Status ◽  
Geometric Morphometric ◽  
Comparative Analyses ◽  
Northern Patagonia ◽  
Geometric Morphometric Analysis ◽  
The Individual ◽  
First Time

Two species of ostracods new to Patagonia, Argentina, are described. One of them, Riocypris whatleyi sp. nov., is described for the first time, and the second, Riocypris sarsi (Daday, 1902) comb. nov., is reallocated from genus Eucypris to genus Riocypris. Inter- and intra-specific variations in shape, size, and sexual dimorphism were evaluated based on geometric morphometric analysis. Moreover, morphological and morphometric comparative analyses were applied to re-examine living and quaternary specimens recovered from previous studies. Based on these results, a generic reassignment for the Patagonian Eucypris fontana (Jurine, 1820) into the genus Riocypris is proposed. Contributing to the knowledge on the systematic and autecology of this enigmatic species, widely distributed in Patagonia and frequently used in paleolimnological reconstructions, generates science-based evidence for their use as indicator species. Additionally, our results emphasize the usefulness of studying the living representatives (i.e., with valves and appendages) for elucidating the taxonomic status of the individual specimens, especially those present in paleontological records and used as bioproxies in paleolimnological studies.

A Geometric Morphometric Assessment of Hand Shape and Comparison to the 2D:4D Digit Ratio as a Marker of Sexual Dimorphism

2013 ◽  
Vol 16 (2) ◽  
pp. 590-600 ◽  
Author(s):  
Paul G. Sanfilippo ◽  
Alex W. Hewitt ◽  
Jenny A. Mountain ◽  
David A. Mackey
Keyword(s):  
Sexual Dimorphism ◽  
Geometric Morphometrics ◽  
Shape Analysis ◽  
Twin Studies ◽  
Analytical Techniques ◽  
Shape Variation ◽  
Geometric Morphometric ◽  
Hand Shape ◽  
Physical Traits ◽  
Biological Shape

Twin studies are extremely useful for investigating hypotheses of genetic influence on a range of behavioral and physical traits in humans. Studies of physical traits, however, are usually limited to size-related biological characteristics because it is inherently difficult to quantify the morphological counterpart – shape. In recent years, the development of geometry-preserving analytical techniques built upon multivariate statistical methodologies has produced a new discipline in biological shape analysis known as geometric morphometrics. In this study of hand shape analysis, we introduce the reader already familiar with the field of twin research to the potential utility of geometric morphometrics and demonstrate the cross-discipline applicability of methods. We also investigate and compare the efficacy of the 2D:4D ratio, a commonly used marker of sexual dimorphism, to the fully multivariate approach of shape analysis in discriminating between male and female sex. Studies of biological shape variation utilizing geometric morphometric techniques may be completed with software freely available on the Internet and time invested to master the small learning curve in concepts and theory.

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