Publications by authors named "Ján Dupej"

25 Publications

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Age-related differences in cranial sexual dimorphism in contemporary Europe.

Int J Legal Med 2021 Mar 1. Epub 2021 Mar 1.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 43, Prague, Czech Republic.

Biomechanical load and hormonal levels tended to change just like the soft and skeletal tissue of the elderly with age. Although aging in both sexes shared common traits, it was assumed that there would be a reduction of sexual dimorphism in aged individuals. The main goals of this study were (1) to evaluate age-related differences in cranial sexual dimorphism during senescence, (2) to determine age-related differences in female and male skulls separately, and (3) to compare skull senescence in Czech and French adult samples as discussed by Musilová et al. (Forensic Sci Int 269:70-77, 2016). The cranial surface was analyzed using coherent point drift-dense correspondence analysis. The study sample consisted of 245 CT scans of heads from recent Czech (83 males and 59 females) and French (52 males and 51 females) individuals. Virtual scans in the age range from 18 to 92 years were analyzed using geometric morphometrics. The cranial form was significantly greater in males in all age categories. After size normalization, sexual dimorphism of the frontal, occipital, and zygomatic regions tended to diminish in the elderly. Its development during aging was caused by morphological changes in both female and male skulls but secular changes must also be taken into account. The most notable aging changes were the widening of the neurocranium and the retrusion of the face, including the forehead, especially after the age of 60 in both sexes. Sexual dimorphism was similar between the Czech and French samples but its age-related differences were partially different because of the population specificity. Cranial senescence was found to degrade the accuracy of sex classification (92-94%) in the range of 2-3%.
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http://dx.doi.org/10.1007/s00414-021-02547-6DOI Listing
March 2021

Palatal growth changes in newborns with unilateral and bilateral cleft lip and palate from birth until 12 months after early neonatal cheiloplasty using morphometric assessment.

Clin Oral Investig 2021 Jan 6. Epub 2021 Jan 6.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 43, Prague 2, Czech Republic.

Objectives: To compare palatal growth changes in infants with complete unilateral (UCLP) or bilateral (BCLP) cleft lip and palate during the first year of life.

Materials And Methods: Upper dental arches of 68 neonates with UCLP and BCLP were evaluated using 2D and 3D morphometry based on dental casts obtained in two age categories (T0 before early neonatal cheiloplasty-UCLP 4 ± 3 days, BCLP 6 ± 5 days; T1 before palatoplasty-UCLP 10 ± 2 months, BCLP 12 ± 3 months).

Results: Intensive palatal growth was manifested in both directions of the palate. Palatal growth in the anterior direction was not restricted, despite the intercanine (CC´) and anterior (LL´) widths being significantly narrowed in the BCLP group (CC´ p = 0.019, LL´ p = 0.009). The posterior dental arches were significantly enlarged (UCLP p ≤ 0.001; BCLP p ≤ 0.001). The negative effect of cleft severity on palatal length was not confirmed (p = 0.802). Variability of the palate was immense mainly in BCLP infants (T0); however, it decreased in both cleft types, confirming the formative effect of palatal growth leading to alveolar cleft closure (UCLP p ≤ 0.001; BCLP p = 0.006 on the right, 0.005 on the left).

Conclusions: Both analyzed cleft groups (UCLP, BCLP) grew favorably during the first year of life, and the palatal growth was not limited in any direction.

Clinical Relevance: Geometric morphometry allowed a comprehensive analysis of the palate, which can contribute to the improvement of surgical methods.
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http://dx.doi.org/10.1007/s00784-020-03711-9DOI Listing
January 2021

Three-dimensional mixed longitudinal study of facial growth changes and variability of facial form in preschool children using stereophotogrammetry.

Orthod Craniofac Res 2020 Dec 21. Epub 2020 Dec 21.

Faculty of Science, Department of Anthropology and Human Genetics, Charles University, Prague 2, Czech Republic.

Objectives: Since the normal, non-pathological facial growth in preschool children is not sufficiently reported, the aim was to follow growth changes of facial surface, sex differences and facial variability in preschool children using 3D stereophotogrammetry.

Settings And Sample Population: Mixed longitudinal sample of healthy Caucasian preschool children without head and facial trauma or craniofacial anomalies from 3.4 to 6.7 years of age consisted of 25 girls and 17 boys.

Materials And Methods: 136 3D facial models from optical scanner Vectra 3D were evaluated by geometric morphometrics (CPC-DCA, PCA, per-vertex t test).

Results: In both sexes, the lower face was widened and elongated, and the prominences of the superciliary arches, lower orbital region, nose, lips and chin increased. Facial surface increments were more even in girls with a maximum between the fourth and fifth year of age, while in boys, there was the most intensive growth between fifth and sixth year of age. Sexual dimorphism was very stable during investigated period, only less statistically significant at the age of 3 years. Boys had more prominent lateral lower part of forehead, nose and lips than girls in every age category.

Conclusions: The longitudinal growth of the face between third and sixth year of age was similar in both sexes, facial sex differences were found in terms of intensity, size and timing. Variability of facial form showed that boys' faces were larger on average and facial shape did not differ. The knowledge of facial growth is essential for diagnostics and clinical practice.
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http://dx.doi.org/10.1111/ocr.12461DOI Listing
December 2020

A test of the Bulut et al. (2016) landmark-free method of quantifying sex differences in frontal bone roundness in a contemporary Czech sample.

J Forensic Sci 2021 Mar 26;66(2):694-699. Epub 2020 Oct 26.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic.

The skull, along with the pelvic bone, serves an important source of clues as to the sex of human skeletal remains. The frontal bone is one of the most significant sexually dimorphic structures employed in anthropological research, especially when studied by methods of virtual anthropology. For this reason, many new methods have been developed, but their utility for other populations remains to be verified. In the present study, we tested one such approach-the landmark-free method of Bulut et al. (2016) for quantifying sexually dimorphic differences in the shape of the frontal bone, developed using a sample of the Turkish population. Our study builds upon this methodology and tests its utility for the Czech population. We evaluated the shape of the male and female frontal bone using 3D morphometrics, comparing virtual models of frontal bones and corresponding software-generated spheres. To do so, we calculated the relative size of the frontal bone area deviating from the fitted sphere by less than 1 mm and used these data to estimate the sex of individuals. Using our sample of the Czech population, the method estimated the sex correctly in 72.8% of individuals. This success rate is about 5% lower than that achieved with the Turkish sample. This method is therefore not very suitable for estimating the sex of Czech individuals, especially considering the significantly greater success rates of other approaches.
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http://dx.doi.org/10.1111/1556-4029.14603DOI Listing
March 2021

Three-dimensional development of the palate in bilateral orofacial cleft newborns 1 year after early neonatal cheiloplasty: Classic and geometric morphometric evaluation.

J Craniomaxillofac Surg 2020 Apr 3;48(4):383-390. Epub 2020 Mar 3.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 43, Prague 2, Czech Republic.

Objectives: The aim of this study was to assess palatal growth in newborns with complete bilateral cleft lip and palate (cBCLP) and bilateral cleft lip and palate with tissue bridges (BCLP + B) 1 year after early neonatal cheiloplasty (ENC).

Material And Methods: The methodology was based on classic and morphometric analysis of dental models of newborns with cBCLP or BCLP + B. These analyses included metric analysis, coherent point drift-dense correspondence analysis, superprojection methods, and multivariate statistics. Dental casts were observed in two age categories, which were compared with each other. The first cast was obtained from each patient before ENC (T0, 5 ± 5 days) and the second one prior to palatoplasty (T1, 12 ± 6 months).

Results: Fifty-two dental models obtained from 26 newborns with cBCLP and BCLP + B were evaluated. The results showed that over the 12-month period, alveolar clefts were narrowed in both cleft types due to anterior growth combined with the formative effect of suturing. This was confirmed by decreases in the dimensions of the right (T0 9.93 ± 2.80 mm, T1 6.64 ± 2.43 mm; p ≤ 0.003) and left (T0 10.71 ± 4.13 mm, T1 6.69 ± 4.29 mm; p ≤ 0.003) alveolar clefts in cBCLP patients. Similar reductions in alveolar cleft widths occurred on the left side (T0 11.69 ± 4.75 mm, T1 4.34 ± 2.97 mm; p ≤ 0.001) of BCLP + B patients, while on the right side, which was connected by a combined tissue bridge, there was non-significant narrowing of the alveolar cleft (T0 1.61 ± 1.34 mm, T1 1.04 ± 0.70 mm; p = 0.120). The ENC did not restrict posterior palatal growth, meaning that intertuberosity width was extended in cBCLP (T0 32.80 ± 3.15 mm, T1 35.86 ± 2.80 mm; p ≤ 0.001) and in BCLP + B neonates (T0 34.01 ± 2.15 mm, T1 36.21 ± 2.14 mm; p ≤ 0.004). Width and length measurements in the observed groups showed growth tendencies equivalent to those in noncleft or LOP patients. Palatal variability was greater in neonatal cBCLP, but was reduced during the monitored period, approximating that for BCLP + B. Regions with the most notable palatal growth were located primarily at the premaxilla and at the anterior and partially posterior ends of the maxillary segments.

Conclusion: Early neonatal cheiloplasty had no negative effect on palatal growth in any direction. There was no reduction in the length or width of the palate during the first year of life, nor was there narrowing of the dentoalveolar arch. The formative effect of the operated lip on the anterior part of the palate was confirmed. This, in combination with the favorable growth, lead to closure of the alveolar cleft.
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http://dx.doi.org/10.1016/j.jcms.2020.02.019DOI Listing
April 2020

Sex estimation using external morphology of the frontal bone and frontal sinuses in a contemporary Czech population.

Int J Legal Med 2019 Jul 14;133(4):1285-1294. Epub 2019 Apr 14.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 44, Prague 2, Czech Republic.

Sex estimation is a task of utmost importance in forensic anthropology and bioarcheology. Along with the pelvic bone, the skull is the most important source of sexual dimorphism. On the human skull, the upper third of the face (i.e., the frontal bone) is one of the most significant sexually dimorphic structures useful in anthropological research, especially when studied by methods of virtual anthropology. This study was focused on sex estimation using the form and shape of the external surface of the frontal bone with or without the inclusion of its sinuses. The study sample consisted of 103 cranial CT images from a contemporary Czech population. Three-dimensional virtual models of the frontal bones and sinuses were analyzed using geometric morphometrics and multidimensional statistics: coherent point drift-dense correspondence analysis (CPD-DCA), principal component analysis (PCA), and support vector machine (SVM). The whole external frontal surface was significantly different between males and females both in form and shape. The greatest total success rate of sex estimation based on form was 93.2%, which decreased to 86.41% after crossvalidation, and this model identified females and males with the same accuracy. The best estimation based on shape reached a success rate of 91.26%, with slightly greater accuracy for females. After crossvalidation, however, the success rate decreased to 83.49%. The differences between sexes were significant also in the volume and surface of the frontal sinuses, but the sex estimation had only 64.07% accuracy after crossvalidation. Simultaneous use of the shape of the frontal surface and the frontal sinuses improved the total success rate to 98.05%, which decreased to 84.46% after crossvalidation.
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http://dx.doi.org/10.1007/s00414-019-02063-8DOI Listing
July 2019

Sex and ancestry related differences between two Central European populations determined using exocranial meshes.

Forensic Sci Int 2019 Apr 26;297:364-369. Epub 2019 Feb 26.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Czech Republic.

Assessing sex and population affinity is an important part of the process of biologically identifying unknown human remains, and the skull is usually one of the best structures for assessing both these components of the biological profile. Population affinity is known to be a hugely important variable when estimating sex because the manifestation of sexually dimorphic traits, body size or social and behavioural habits differs across populations. Therefore, for forensic purposes, the estimation of ancestry is a necessary step in the identification of bone remains. The present study improves on the results of a previously developed virtual method using the exocranial surface for sex estimation and assessing population affinity. The ability to assess these components of the biological profile was successfully tested on 208 individuals from two recent European populations. The original classifier was based on geometric morphometric analyses (CPD-DCA, PCA, SVM) and was able to assess the sex of individuals belonging to one French population with an accuracy exceeding 90 % Musilová et al. [1]. To improve the reliability of the method, the Czech population sample was added to the dataset, yielding the highest accuracy of 96.2 %; using the combined dataset, the reliability of the method was 91.8 %. Secondly, we used the same method utilizing inter-population differences to classify individuals based on the shape of the skull. The greatest accuracy rate was 92.8 %, which makes our method a promising tool for sex estimation and assessing population affinity.
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http://dx.doi.org/10.1016/j.forsciint.2019.02.034DOI Listing
April 2019

Simulation of facial growth based on longitudinal data: Age progression and age regression between 7 and 17 years of age using 3D surface data.

PLoS One 2019 22;14(2):e0212618. Epub 2019 Feb 22.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic.

Modelling of the development of facial morphology during childhood and adolescence is highly useful in forensic and biomedical practice. However, most studies in this area fail to capture the essence of the face as a three-dimensional structure. The main aims of our present study were (1) to construct ageing trajectories for the female and male face between 7 and 17 years of age and (2) to propose a three-dimensional age progression (age -regression) system focused on real growth-related facial changes. Our approach was based on an assessment of a total of 522 three-dimensional (3D) facial scans of Czech children (39 boys, 48 girls) that were longitudinally studied between the ages of 7 to 12 and 12 to 17 years. Facial surface scans were obtained using a Vectra-3D scanner and evaluated using geometric morphometric methods (CPD-DCA, PCA, Hotelling's T2 tests). We observed very similar growth rates between 7 and 10 years in both sexes, followed by an increase in growth velocity in both sexes, with maxima between 11 and 12 years in girls and 11 to 13 years in boys, which are connected with the different timing of the onset of puberty. Based on these partly different ageing trajectories for girls and boys, we simulated the effects of age progression (age regression) on facial scans. In girls, the mean error was 1.81 mm at 12 years and 1.7 mm at 17 years. In boys, the prediction system was slightly less successful: 2.0 mm at 12 years and 1.94 mm at 17 years. The areas with the greatest deviations between predicted and real facial morphology were not important for facial recognition. Changes of body mass index percentiles in children throughout the observation period had no significant influence on the accuracy of the age progression models for both sexes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0212618PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6386244PMC
November 2019

Modeling age-specific facial development in Williams-Beuren-, Noonan-, and 22q11.2 deletion syndromes in cohorts of Czech patients aged 3-18 years: A cross-sectional three-dimensional geometric morphometry analysis of their facial gestalt.

Am J Med Genet A 2018 12 31;176(12):2604-2613. Epub 2018 Oct 31.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague 2, Czech Republic.

Three-dimensional (3D) virtual facial models facilitate genotype-phenotype correlations and diagnostics in clinical dysmorphology. Within cross-sectional analysis of both genders we evaluated facial features in representative cohorts of Czech patients with Williams-Beuren-(WBS; 12 cases), Noonan-(NS; 14), and 22q11.2 deletion syndromes (22q11.2DS; 20) and compared their age-related developmental trajectories to 21 age, sex and ethnically matched controls in 3-18 years of age. Using geometric morphometry statistically significant differences in facial morphology were found in all cases compared to controls. The dysmorphic features observed in WBS were specific and manifested in majority of cases. During ontogenesis, dysmorphic features associated with increased facial convexity become more pronounced whereas other typical features remained relatively stable. Dysmorphic features observed in NS cases were mostly apparent during childhood and gradually diminished with age. Facial development had a similar progress as in controls, while there has been increased growth of patients' nose and chin in adulthood. Facial characteristics observed in 22q11.2DS, except for hypoplastic alae nasi, did not correspond with the standard description of its facial phenotype because of marked facial heterogeneity of this clinical entity. Because of the sensitivity of 3D facial morphometry we were able to reach statistical significance even in smaller retrospective patient cohorts, which proves its clinical utility within the routine setting.
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http://dx.doi.org/10.1002/ajmg.a.40659DOI Listing
December 2018

Kinship and morphological similarity in the skeletal remains of individuals with known genealogical data (Bohemia, 19th to 20th centuries): A new methodological approach.

Am J Phys Anthropol 2018 11 20;167(3):541-556. Epub 2018 Aug 20.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Czech Republic.

Objectives: This article proposes a new approach, called the "similarity coefficient" (SC) for verifying family relationships from skeletal remains using nonmetric traits. Based on this method and further analyses, the authors aim to show the degree of similarity between individuals with varying degrees of kinship, including inbred individuals.

Materials And Methods: Our sample includes the skeletal remains of 34 individuals with known genealogical data (four generations, 19th to 20th centuries). A total of 243 skeletal nonmetric traits were evaluated with respect to their anatomical characteristics. The SC was calculated by quantifying the agreement of trait occurrence between individuals. We also identified the traits that support the biological relationships of particular individuals by accounting for their population frequencies.

Results: There was a positive correlation between the morphological similarity of biologically related individuals and their biological distance. In some cases, we found greater degree of morphological similarity between first cousins than among other close relatives such as parents and children. At the same time, there was no statistically significant difference in the degree of similarity between inbred individuals and common relatives. Proven family relationships were best reflected by cranial traits, especially bone bridges associated with the courses of blood vessels and nerves.

Conclusions: The use of skeletal nonmetric traits for the detection of relatives is possible. There is a relationship between biological distance and the degree of morphological similarity in related individuals. It also appears that inbreeding, despite previous assumptions, does not lead to a significant reduction in morphological variation.
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http://dx.doi.org/10.1002/ajpa.23683DOI Listing
November 2018

Three-dimensional assessment of facial asymmetry in preschool patients with orofacial clefts after neonatal cheiloplasty.

Int J Pediatr Otorhinolaryngol 2018 May 16;108:40-45. Epub 2018 Feb 16.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Vinicna 7, 128 44 Prague 2, Czech Republic.

Objectives: To evaluate facial asymmetry changes in pre-school patients with orofacial clefts after neonatal cheiloplasty and to compare facial asymmetry with age-matched healthy controls.

Methods And Materials: The sample consisted of patients with unilateral cleft lip (UCL), unilateral cleft lip and palate (UCLP), and bilateral cleft lip and palate (BCLP). The patients were divided in two age groups with a mean age of 3 years (n = 51) and 4.5 years (n = 45), respectively, and 78 age-matched individuals as controls. Three-dimensional (3D) facial scans were analyzed using geometric morphometry and multivariate statistics.

Results: Geometric morphometry showed positive deviations from perfect symmetry on the right side of the forehead in the intervention groups and the controls. The UCL groups showed the greatest asymmetric nasolabial area on the cleft-side labia and the contralateral nasal tip. The UCLP group showed, moreover, asymmetry in buccal region due to typical maxillar hypoplasia, which was accentuated in the older group. The BCLP groups showed slightly similar but greater asymmetry than the control groups, except for the philtrum region.

Conclusions: Asymmetry of each of the cleft groups significantly differed from the controls. Except for the buccal region in the UCLP and BCLP groups, asymmetry did not significantly increase with age.
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http://dx.doi.org/10.1016/j.ijporl.2018.02.023DOI Listing
May 2018

Sex-specific functional adaptation of the femoral diaphysis to body composition.

Am J Hum Biol 2018 07 24;30(4):e23123. Epub 2018 Mar 24.

Department of Anthropology and Human Genetics, Faculty of Natural Sciences, Charles University - Viničná 7, 128 43 Prague 2, Czech Republic.

Objectives: The human femoral diaphysis is often used to reconstruct loading histories (mobility, activity, body mass). The proximal femur is known to be differentially affected by changes in total fat-mass (FM), fat-free mass (FFM), and body fat percentage (BF%), but the adaptation of the entire diaphysis to body composition has not been thoroughly characterized to date. Understanding how the femoral diaphysis adapts to body components would benefit biomechanical interpretations of the femoral variation and nutrition-related studies.

Methods: Combining various methods from clinical nutrition, biological anthropology, and geometric morphometrics, we evaluated the correlation of measures taken on the entire femoral diaphysis with estimated FM, FFM, and BF% from 61 CT scans (17 females, 44 males). The sample was predominantly composed of people with obesity.

Results: Cortical area of the cross-sections and local cortical thickness showed high correlation with BF% in particular, in females only. The curvature significantly decreased with FM and BF% in both sexes. The lowest correlations are found with FFM.

Conclusions: The observed sexual dimorphism is consistent with differing aging processes; cortical bone decreases in females through endosteal resorption while it remains almost constant in males who compensate for endosteal resorption by periosteal apposition on the diaphyseal surface. The functional adaptation to compressive forces indicates a systemic endosteal apposition of bone material with increased BF% and FM in females only. FM and BF% are linked to a straighter femur in both sexes, suggesting an optimization of the resistance to compressive loads by distributing them more linearly along the entire diaphysis.
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http://dx.doi.org/10.1002/ajhb.23123DOI Listing
July 2018

Body mass estimation from the skeleton: An evaluation of 11 methods.

Forensic Sci Int 2017 Dec 22;281:183.e1-183.e8. Epub 2017 Nov 22.

Charles University, Laboratory of 3D Imaging and Analytical Methods, Department of Anthropology and Human Genetics, Faculty of Natural Sciences, Viničná 7, 128 43 Prague 2, Czech Republic; Université de Bordeaux, PACEA, UMR 5199, CNRS - Bâtiment B8, Allée Geoffroy Saint Hilaire, CS 50023, F-33400 Talence, France.

Estimating an individual body mass (BM) from the skeleton is a challenge for forensic anthropology. However, identifying someone's BMI (Body Mass Index) category, i.e. underweight, normal, overweight or obese, could contribute to identification. Individual BM is also known to influence the age-at-death estimation from the skeleton. Several methods are regularly used by both archaeologists and forensic practitioners to estimate individual BM. The most commonly used methods are based on femoral head breadth, or stature and bi-iliac breadth. However, those methods have been created from mean population BMs and are therefore meant to estimate the average BM of a population. Being that they are based on individual BM data and estimated femoral cortical areas, the newest published methods are supposed to be more accurate. We evaluated the accuracy and reliability of the most commonly used and most recent BM estimation methods (n=11) on a sample of 64 individuals. Both sexes and all BMI categories are represented, as well as a wide range of BM. Ages in this sample range from 20 to 87 years of age. Absolute and real differences between actual BM and estimated BM were assessed; they determined the accuracy for individual BM estimation and for average BM estimation of a population, respectively. The proportion of the sample whose estimated BM falls within ±10% and ±20% of their actual BM determines the reliability of the methods in our sample for, respectively, individual BM estimation and average BM of a population. The tested methods result in an absolute difference of 11kg-26kg±10kg with regards to prediction of individuals actual BM. The real differences are very variable from method to method, ranging from -14kg to 25kg. None of the tested methods is able to estimate BM of half of the sample within ±10% of their actual BM but most of them can estimate BM of more than half of the sample within ±20% of their actual BM. The errors increase with increasing BM, demonstrating a bias in all the methods. No bone variable tested correlated with BM. BMI categories were correctly predicted for less than 50% of the sample in most cases. In conclusion, our study demonstrates that the 11 methods tested are not suited for estimating individual BM or for predicting BMI categories. However, they are accurate and reliable enough for estimating the average BM of a population.
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http://dx.doi.org/10.1016/j.forsciint.2017.10.026DOI Listing
December 2017

Facial skeleton asymmetry and its relationship to mastication in the Early Medieval period (Great Moravian Empire, Mikulčice, 9th-10th century).

Arch Oral Biol 2017 Dec 19;84:64-73. Epub 2017 Sep 19.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, 128 43, Prague, Czech Republic.

Objectives: The aim of this study was to analyse the relationship of mastication and directional asymmetry (DA) of upper facial skeleton in Early Medieval sample from the Mikulčice settlement (Czech Republic).

Design: The settlement is divided into two burial areas of presumably different socioeconomic status: the castle and the sub-castle. The material consisted of 193 individuals (125 castle, 68 sub-castle). The relationship of facial skeleton DA and mastication was analysed by examining tooth wear and mandibular shape by means of 3D geometric morphometrics. Tooth wear of premolars and molars was evaluated using appropriate scoring systems. 3D coordinates of 35 mandibular landmarks were scanned using MicroScribe G2X digitizing system.

Results: The results did not reveal any significant differences in tooth wear DA or mandible DA values between burial areas or sexes. Mandibular shape, however, differed significantly between burial areas and sexes. Directional changes of mandibular landmarks supported a right chewing side preference in the sample. Significant relationship between upper facial skeleton DA and mandible DA was recorded.

Conclusions: Differences in subsistence between burial areas and sexes did not translate into differences in mandible DA and dental wear. However, mandibular shape analysis revealed prominence of areas affected by masticatory muscles in individuals from the castle. Higher consumption of tough material, such as meat, has been proposed as possible explanation. The right side was found to be preferential for chewing. The relationship between upper facial skeleton DA and mandible DA was concluded to be the result of the compensatory and adaptive function of mandible.
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http://dx.doi.org/10.1016/j.archoralbio.2017.09.015DOI Listing
December 2017

Semiautomatic extraction of cortical thickness and diaphyseal curvature from CT scans.

Am J Phys Anthropol 2017 12 15;164(4):868-876. Epub 2017 Sep 15.

Department of Anthropology and Human Genetics, Faculty of Sciences, Charles University, Viničná 7, Praha 2, 128 43, Czech Republic.

The understanding of locomotor patterns, activity schemes, and biological variations has been enhanced by the study of the geometrical properties and cortical bone thickness of the long bones measured using CT scan cross-sections. With the development of scanning procedures, the internal architecture of the long bones can be explored along the entire diaphysis. Recently, several methods that map cortical thickness along the whole femoral diaphysis have been developed. Precise homology is vital for statistical examination of the data; however, the repeatability of these methods is unknown and some do not account for the curvature of the bones. We have designed a semiautomatic workflow that improves the morphometric analysis of cortical thickness, including robust data acquisition with minimal user interaction and considering the bone curvature. The proposed algorithm also performs automatic landmark refinement and rigid registration on the extracted morphometric maps of the cortical thickness. Because our algorithm automatically reslices the diaphysis into 100 cross-sections along the medial axis and uses an adaptive thresholding method, it is usable on CT scans that contain soft tissues as well as on bones that have not been oriented specifically prior to scanning. Our approach exhibits considerable robustness to error in user-supplied landmarks, suppresses distortion caused by the curvature of the bones, and calculates the curvature of the medial axis.
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http://dx.doi.org/10.1002/ajpa.23315DOI Listing
December 2017

Stability of upper face sexual dimorphism in central European populations (Czech Republic) during the modern age.

Int J Legal Med 2018 Jan 21;132(1):321-330. Epub 2017 Jun 21.

National Museum Prague, Václavské náměstí 68, 115 79, Prague 1, Czech Republic.

One of the most fundamental issues in forensic anthropology is the determination of sex and population affinity based on various skeletal elements. Therefore, we compared the sexual dimorphism of the upper facial skeleton from a recent Czech population (twenty-first century) with that of a population from Early Modern Age Bohemia (sixteenth to eighteenth centuries). Methods of geometric morphometrics were applied. According to the results, sexual dimorphism in terms of size, shape, and form was statistically significant in both populations. The best results of sex estimation originated from analyses of form. Thus, both size and shape differences should be taken into account for determination of the sex. The accuracy of prediction achieved 91.1% for individuals in the recent population and 87.5% for individuals from the early modern population. Only minor differences were found between sexual dimorphism in the studied populations. We conclude that sexual dimorphism of the upper facial skeleton is stable during the relatively short time period.
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http://dx.doi.org/10.1007/s00414-017-1625-3DOI Listing
January 2018

Geometric morphometric and traditional methods for sex assessment using the posterior ilium.

Leg Med (Tokyo) 2017 May 18;26:52-61. Epub 2017 Mar 18.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic; UMR 5199 PACEA, University of Bordeaux, Bâtiment B8, Allée Geoffroy Saint Hillaire, 33615 Pessac, France.

The human hip bone is generally accepted as the most reliable bone for sex estimation in forensic and bioarchaeological disciplines. However, it is seldom completely preserved. The best preserved region is typically around the sacroiliac joint and its auricular surface; it is therefore surprising that this surface has not been involved in standard sexing methods. The aim of this study was to explore the shape and size sexual dimorphism of the auricular surface in detail and to compare its sex estimation accuracy using the geometric morphometric (GM) and traditional methodological approach. Our sample consisted of 121 specimens from 3 European osteological collections. The GM part of the study was based on 2D sliding semilandmarks that covered the outline of the auricular surface. Furthermore, several linear measurements and visual features (e.g. auricular surface elevation, postauricular sulcus) were chosen to test sex estimation accuracy using support vector machines. Concerning the GM analysis, the most notable sexual differences in the auricular surface outline relate to size. The best accuracy was achieved using form variables reaching 81.0%. Comparable accuracy (80.2%) was achieved using the metric approach, but combined with visual features the accuracy was increased to 93.4%. The GM approach was not very efficient in sexing the auricular surface outline, but the combination of visual features from the posterior ilium and metric variables of the auricular surface could be useful in sex estimation. Therefore, we provide a further testable linear discriminant equation based on this combination of variables.
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http://dx.doi.org/10.1016/j.legalmed.2017.03.004DOI Listing
May 2017

Body composition estimation from selected slices: equations computed from a new semi-automatic thresholding method developed on whole-body CT scans.

PeerJ 2017 18;5:e3302. Epub 2017 May 18.

Faculty of Natural Sciences, Department of Anthropology and Human Genetics, Charles University, Prague, Czech Republic.

Background: Estimating volumes and masses of total body components is important for the study and treatment monitoring of nutrition and nutrition-related disorders, cancer, joint replacement, energy-expenditure and exercise physiology. While several equations have been offered for estimating total body components from MRI slices, no reliable and tested method exists for CT scans. For the first time, body composition data was derived from 41 high-resolution whole-body CT scans. From these data, we defined equations for estimating volumes and masses of total body AT and LT from corresponding tissue areas measured in selected CT scan slices.

Methods: We present a new semi-automatic approach to defining the density cutoff between adipose tissue (AT) and lean tissue (LT) in such material. An intra-class correlation coefficient (ICC) was used to validate the method. The equations for estimating the whole-body composition volume and mass from areas measured in selected slices were modeled with ordinary least squares (OLS) linear regressions and support vector machine regression (SVMR).

Results And Discussion: The best predictive equation for total body AT volume was based on the AT area of a single slice located between the 4th and 5th lumbar vertebrae (L4-L5) and produced lower prediction errors (|PE| = 1.86 liters, %PE = 8.77) than previous equations also based on CT scans. The LT area of the mid-thigh provided the lowest prediction errors (|PE| = 2.52 liters, %PE = 7.08) for estimating whole-body LT volume. We also present equations to predict total body AT and LT masses from a slice located at L4-L5 that resulted in reduced error compared with the previously published equations based on CT scans. The multislice SVMR predictor gave the theoretical upper limit for prediction precision of volumes and cross-validated the results.
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http://dx.doi.org/10.7717/peerj.3302DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5438582PMC
May 2017

Exocranial surfaces for sex assessment of the human cranium.

Forensic Sci Int 2016 Dec 11;269:70-77. Epub 2016 Nov 11.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czechia.

Determination of sex is one of the most important and challenging disciplines in biological anthropology. Creating a robust tool for sexing crania is crucial for forensic anthropology, especially in this period of migration, travel, and globalization, when different populations are mixed together in one region. Many different approaches to sex estimation using the skull have been published; however, population specificity and oscillation of variable sexual dimorphism typically reduces their effectiveness. The aim of this study was to create a robust classifier using virtual anthropology without the use of a CT scanner. The entire cranial surface was analyzed using coherent point drift-dense correspondence analysis and classification was performed using a support vector machine with a radial kernel, minimizing subjective error. The study sample consisted of 103 CT scans of a recent southern French population. Virtual scans of 52 males and 51 females (age from 18 to 92) were analyzed using 3D software systems (Rapidform, Avizo, Morphome3cs) and innovative approaches in geometric morphometrics. Leave-one-out crossvalidation was also applied. Sex differences in shape and form were displayed by colour scale maps. The whole cranial surface was significantly different between males and females in size (form). Sexual dimorphism was significantly lower in senile skulls. The most exclusive areas were the supraorbital region, orbits, cheek bones, nasal apertures, mastoids, and external occipital protuberances. The method provided a high level of classification accuracy (90.3%) in sexing male and female skulls and is a valuable tool for sex determination.
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http://dx.doi.org/10.1016/j.forsciint.2016.11.006DOI Listing
December 2016

Palatal growth in complete unilateral cleft lip and palate patients following neonatal cheiloplasty: Classic and geometric morphometric assessment.

Int J Pediatr Otorhinolaryngol 2016 Nov 31;90:71-76. Epub 2016 Aug 31.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Viničná 7, 128 43, Prague 2, Czech Republic.

Background: A new method of early neonatal cheiloplasty has recently been employed on patients having complete unilateral cleft lip and palate (cUCLP). We aimed to investigate (1) their detailed palatal morphology before surgery and growth during the 10 months after neonatal cheiloplasty, (2) the growth of eight dimensions of the maxilla in these patients, (3) the development of these dimensions compared with published data on noncleft controls and on cUCLP patients operated using later operation protocol (LOP; 6 months of age).

Methods: Sixty-six virtual dental models of 33 longitudinally evaluated cUCLP patients were analysed using metric analysis, a dense correspondence model, and multivariate statistics. We compared the palatal surfaces before neonatal cheiloplasty (mean age, 4 days) and before palatoplasty (mean age, 10 months).

Results: The palatal form variability of 10-month-old children was considerably reduced during the observed period thanks to their undisturbed growth, that is, the palate underwent the same growth changes following neonatal cheiloplasty. A detailed colour-coded map identified the most marked growth at the anterior and posterior ends of both segments. The maxilla of cUCLP patients after neonatal cheiloplasty had a growth tendency similar to noncleft controls (unlike LOP).

Conclusions: Both methodological approaches showed that early neonatal cheiloplasty in cUCLP patients did not prevent forward growth of the upper jaw segments and did not reduce either the length or width of the maxilla during the first 10 months of life.
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http://dx.doi.org/10.1016/j.ijporl.2016.08.028DOI Listing
November 2016

Disregarding population specificity: its influence on the sex assessment methods from the tibia.

Int J Legal Med 2017 Jan 20;131(1):251-261. Epub 2016 Jul 20.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Viničná 7, Praha 2, 128 43, Prague, Czech Republic.

Forensic anthropology has developed classification techniques for sex estimation of unknown skeletal remains, for example population-specific discriminant function analyses. These methods were designed for populations that lived mostly in the late nineteenth and twentieth centuries. Their level of reliability or misclassification is important for practical use in today's forensic practice; it is, however, unknown. We addressed the question of what the likelihood of errors would be if population specificity of discriminant functions of the tibia were disregarded. Moreover, five classification functions in a Czech sample were proposed (accuracies 82.1-87.5 %, sex bias ranged from -1.3 to -5.4 %). We measured ten variables traditionally used for sex assessment of the tibia on a sample of 30 male and 26 female models from recent Czech population. To estimate the classification accuracy and error (misclassification) rates ignoring population specificity, we selected published classification functions of tibia for the Portuguese, south European, and the North American populations. These functions were applied on the dimensions of the Czech population. Comparing the classification success of the reference and the tested Czech sample showed that females from Czech population were significantly overestimated and mostly misclassified as males. Overall accuracy of sex assessment significantly decreased (53.6-69.7 %), sex bias -29.4-100 %, which is most probably caused by secular trend and the generally high variability of body size. Results indicate that the discriminant functions, developed for skeletal series representing geographically and chronologically diverse populations, are not applicable in current forensic investigations. Finally, implications and recommendations for future research are discussed.
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http://dx.doi.org/10.1007/s00414-016-1413-5DOI Listing
January 2017

Facial soft tissue thicknesses in the present Czech Population.

Forensic Sci Int 2016 Mar 15;260:106.e1-106.e7. Epub 2016 Jan 15.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic.

The aim of this study was to find any relation between soft facial tissue thickness (FSTT) and sex, age and asymmetry in the contemporary Czech population. The studied sample consisted of head CT scans of 102 adult Czech individuals between the ages of 21 and 83. Forty FSTTs were evaluated and analysed using PCA, Hotelling's T(2) test, LDA, the Kolmogorov-Smirnov test, MANOVA, the Kruskal-Wallis test and Wilcoxon's paired test. The greatest sexual dimorphism was detected in the lower part of the face, which had discriminant power almost the same as the entire faces (approximately 80%). On the other hand, a significant influence of aging was shown, mostly in the area of the upper face (In females, twice as many landmarks displayed a significant influence, compared with males). The influence of asymmetry was confirmed in seven bilateral landmarks, five of them favouring the right side.
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http://dx.doi.org/10.1016/j.forsciint.2016.01.011DOI Listing
March 2016

Sexual dimorphism of facial appearance in ageing human adults: A cross-sectional study.

Forensic Sci Int 2015 Dec 22;257:519.e1-519.e9. Epub 2015 Oct 22.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic.

In the forensic sciences, knowledge of facial ageing is very important in searching for both dead and living individuals. Ageing estimations typically model the biological profile, which can be compared to missing persons. The main goals of this current study were to construct ageing trajectories for adult human faces of both sexes and evaluate sexual dimorphism in relation to static allometry. Our study was based on the analysis of three-dimensional facial surface models of 194 individuals 20-80 years of age. The evaluation consisted of a dense correspondence analysis of facial scans and multivariate statistics. It was shown that both age and sex have a significant influence on facial form and shape. Male features included a longer face, with more protruded foreheads, eyebrow ridges and nose, including the region under the upper lip and mandible region, but more retruded cheeks compared to females. Ageing in both sexes shared common traits, such as more pronounced roundness of the face (rectangular in males), decreased facial convexity, increased visibility of skin folds and wrinkles connected with the loss of skin elasticity, and soft tissue stretching, especially in the orbital area and lower face; however, male faces exhibited more intense ageing changes. The above-mentioned sexual dimorphic traits tended to diminish in the elderly age category, though overall sexual dimorphism was heightened with age. The static allometric relationships between size and form or shape were similar in both sexes, except that the larger faces of elderly males displayed more intensive ageing changes.
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http://dx.doi.org/10.1016/j.forsciint.2015.09.008DOI Listing
December 2015

Modelling of facial growth in Czech children based on longitudinal data: Age progression from 12 to 15 years using 3D surface models.

Forensic Sci Int 2015 Mar 13;248:33-40. Epub 2014 Dec 13.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Czech Republic.

Dealing with the increasing number of long-term missing children and juveniles requires more precise and objective age progression techniques for the prediction of their current appearance. Our contribution includes detailed and real facial growth information used for modelling age progression during adolescence. This study was based on an evaluation of the overall 180 three-dimensional (3D) facial scans of Czech children (23 boys, 22 girls), which were longitudinally studied from 12 to 15 years of age and thus revealed the real growth-related changes. The boys underwent more marked changes compared with the girls, especially in the regions of the eyebrow ridges, nose and chin. Using modern geometric morphometric methods, together with their applications, we modelled the ageing and allometric trajectories for both sexes and simulated the age-progressed effects on facial scans. The facial parts that are important for facial recognition (eyes, nose, mouth and chin) all deviated less than 0.75mm, whereas the areas with the largest deviations were situated on the marginal parts of the face. The mean error between the predicted and real facial morphology obtained by modelling the children from 12 to 15 years of age was 1.92mm in girls and 1.86mm in boys. This study is beneficial for forensic artists as it reduces the subjectivity of age progression methods.
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http://dx.doi.org/10.1016/j.forsciint.2014.12.005DOI Listing
March 2015

Technical note: geometric morphometrics and sexual dimorphism of the greater sciatic notch in adults from two skeletal collections: the accuracy and reliability of sex classification.

Am J Phys Anthropol 2013 Dec 30;152(4):558-65. Epub 2013 Sep 30.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University in Prague, Prague, 12844, Czech Republic.

The greater sciatic notch (GSN) is one of the most important and frequently used characteristics for determining the sex of skeletons, but objective assessment of this characteristic is not without its difficulties. We tested the robustness of GSN sex classification on the basis of geometric morphometrics (GM) and support vector machines (SVM), using two different population samples. Using photographs, the shape of the GSN in 229 samples from two assemblages (documented collections of a Euroamerican population from the Maxwell Museum, University of New Mexico, and a Hispanic population from Universidad Nacional Autónoma de México, Mexico City) was segmented automatically and evaluated using six curve representations. The optimal dimensionality for each representation was determined by finding the best sex classification. The classification accuracy of the six curve representations in our study was similar but the highest and concurrently homologous cross-validated accuracy of 92% was achieved for a pooled sample using Fourier coefficient and Legendre polynomial methods. The success rate of our classification was influenced by the number of semilandmarks or coefficients and was only slightly affected by GSN marginal point positions. The intrapopulation variability of the female GSN shape was significantly lower compared with the male variability, possibly as a consequence of the intense selection pressure associated with reproduction. Males were misclassified more often than females. Our results show that by using a suitable GSN curve representation, a GM approach, and SVM analysis, it is possible to obtain a robust separation between the sexes that is stable for a multipopulation sample.
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http://dx.doi.org/10.1002/ajpa.22373DOI Listing
December 2013