Integration patterns of the asymmetric components of the skull: A covariational statistical approach on a modern greek sample

Objectives: The integration patterns of the asymmetric components of the skull can be informative, especially in the diagnosis and surgical treatment planning of patients. This research aims to explore the interactions of the asymmetric components between the mandible, the basicranium, and the upper face. Material and methods: The sample comprises 100 skulls of Greek adults and the three-dimensional coordinates of 35 landmarks, extracted from the cranial and mandibular virtual 3D bones, were analyzed using the generalized least-squares Procrustes method. The integration patterns of the asymmetric components of the shapes of the specific structures were evaluated through partial least-squares correlation analysis with a two-blocks approach. Results: When handling the skull regions separately, there is statistically significant integration of the asymmetric components between the mandible and the basicranium as well as between the mandible and the upper face. Furthermore, the mandible and the basicranium exhibit the strongest interaction among the three pairs examined. Conclusions: The asymmetric variation of the skull regions should be taken into consideration for surgical treatment planning. However, comparing our findings with other studies revealed that the utilization of the skull regions in the context of a structure as a whole while running the analysis, as well as different landmark combinations, may lead to different results. Furthermore, there might be population-specificity to certain integration patterns of the asymmetric component of the total shape variation among skull regions. Hence, surgical bone restoration, especially in the mandible, should consider overall skull asymmetry and population-specific data to ensure optimal integration. © 2021 E. Schweizerbart’sche Verlagsbuchhandlung, 70176 Stuttgart, Germany

Validation study of osteometric techniques for sorting commingled human skeletal remains in archaeological samples

The biological profile of human remains is fundamental for understanding the structure of past societies and their life histories. However, the assessment of the demographics of an assemblage is hindered when dealing with commingled burials. Consequently, methods for sorting commingled skeletons are essential in a bioarchaeological context. The aim of this study was to provide insight into osteometric sorting techniques when dealing with archaeological commingled skeletal remains. For the purposes of this research, Byrd and LeGarde's pair-matching osteometric sorting and regression models, which use measurements created for fragmented bones, were tested on 61 adult individuals exhumed from single burial plots from five different Greek archaeological sites. The results showed that the regression models exhibit much lower rates of true positive results (18.2–67.6% and 4.8–71.7% for the left and right side, respectively) than the pair-matching model (74.1–89.5%), whereas the rates of the false positive results are almost equivalent (approximately 20–35%). Therefore, the application of the pair-matching osteometric sorting model can provide a set of potential matches in an archaeological context. However, it is essential to utilize other techniques as well, in order to verify the results. © 2019 John Wiley & Sons, Ltd

A novel method for analyzing long bone diaphyseal cross-sectional geometry. A GNU Octave CSG Toolkit

The diaphyseal cross-sectional geometric properties of the humerus, femur and tibia have been extensively used for studying their adaptation to mechanical loading. To date common practices for such studies involve either computed tomography or the latex cast method in conjunction with image analysis for calculating such properties. With the advent of modern laser scanning and photogrammetry technologies in biological anthropology, the computation of the cross-sectional geometric properties directly from 3D models is a viable and sensible alternative. Nevertheless, such method has not been properly implemented as yet. A dedicated toolkit, named long-bone-diaphyseal-CSG-Toolkit, comprising a set of functions for the GNU Octave programming language, is presented here. Offering a robust analytical implementation and an easy to follow application either for a single bone or in batch-processing mode, the toolkit requires minimum user intervention and also provides functionality for graphical representation of the calculated periosteal contours and their respective cross-sectional geometric properties. Finally, the long-bone-diaphyseal-CSG-Toolkit utilizes advanced optimization algorithms, which eliminate intra- and inter-observer error by reliably orienting the cross-sectional contours to a well-defined orientation and close to the bone's true anatomical position, which provides a significant advantage over the latex cast method. © 2019 Elsevier B.V

Secular change in adult stature of modern Greeks

Objectives: In Greece, during the late 19th and early 20th century, the rural population adopted a more or less urban lifestyle. Furthermore, the first half of the 20th century finds Greece involved in five major wars, including a civil war, and consequent financial deprivation. This study investigates how the socioeconomic changes in Greece, during this period of time, have affected the stature of its population. Methods: The Athens collection constitutes our sample with 189 adult individuals (104 males and 85 females). Stature was estimated with regression equations and secular change was evaluated by linear regression of stature with respect to the year of birth. Further analysis of our population sample was based on three time periods to explore the correlation between secular change and historical events. Results: From 1879 to 1965, stature increased for both males and females. The subsequent analysis among different periods revealed that the male group exhibited a small although non-significant decline in stature during the years 1912 to 1950, which coincides with the long inter-war period. However, females appear less affected by the consequent deprivation. Conclusions: Our findings are consistent with earlier studies based on a much smaller time span. The negative effect of the economic and nutritional deprivation on stature as a result of warfare is apparent in our sample, at least for males. Furthermore, the positive effect of economic growth on stature is prominent for the entire population in the postwar period. © 2017 Wiley Periodicals, Inc

Advances in Osteometric Sorting: Utilizing Diaphyseal CSG Properties for Lower Limb Skeletal Pair-Matching

Pair-matching of bilateral elements is a major component of resolving commingled remains both in forensic and bioarchaeological contexts. This study presents a new method of osteometric pair-matching of the lower limbs which relies on 3D digital models of the femur and tibia bones. The proposed method, which is accompanied by a freely available open-source implementation, automatically computes a number of osteometric variables including cross-sectional geometric properties from an assemblage of left and right bone antimeres and calculates probabilistically the appropriate matching pairs as well as single elements, whose bones antimere is not present in the given assemblage. The method has been extensively tested on a skeletal sample comprising 396 femurs and 422 tibias from the Athens collection. Our results in testing commingled assemblages with no disparity show that the method’s sensitivity is 1 for sorting femurs and 0.997 for sorting tibias, whereas in assemblages with moderate disparity the sensitivity is 0.999 and 0.992 respectively. Our results further indicate that sensitivity is unaffected by the size of the commingled assemblage although the percentage of identified true matching pairs drops as the number of commingled elements increases. This means that all identified antimeres matched to an individual are still very accurately sorted despite not every individual being identified in very large assemblages. The proposed method can facilitate the sorting process of commingled remains both accurately and efficiently, while leaving a very small percentage of unsorted elements that may require further techniques for further individualization. © 2020 American Academy of Forensic Science

Identification of skeletal remains from a Mycenaean burial in Kastrouli-Desfina, Greece

The present work details the findings of the anthropological study of the skeletal material unearthed from the Kastrouli archaeological site on July 2016. The skeletal material was significantly deteriorated with most of the bones fragmented beyond a level to yield any information. Despite almost no single bone was found intact, hence no metrics for stature estimation are provided herein, a number of sufficiently preserved femur bones along with numerous teeth were identified and allowed for MNI estimates for this commingled burial. We identified 15 adults along with 2 subadults, an infant and a fetus. Skeletal remains of domesticated animals were also recovered from the same undisturbed context, for which the recovered archaeological artifacts suggest that the tomb was Mycenaean/Late Helladic in date. © 2017 MAA

Advancements in sex estimation using the diaphyseal cross-sectional geometric properties of the lower and upper limbs

This paper introduces an automated method for estimating sex from the lower and upper limbs based on diaphyseal CSG properties. The proposed method was developed and evaluated using 389 femurs, 412 tibias, and 404 humeri of adult individuals from a modern Greek reference sample, the Athens Collection. The skeletal properties, which were extracted with the CSG-Toolkit, were analyzed with step-wise DFA (evaluated with LOOCV) and subsequently with RBF kernel SVM supervised learning. SVM cross-validation was based on a 20-fold stratified random sample splitting as well as a chronological split based on year of birth to further assess the effect of secular change in sex estimation capacity. Maximum cross-validated classification accuracy from step-wise DFA reached 94.8% for the femur, 94.7% for the tibia, and 97.3% for the humerus, whereas SVM cross-validated results were similar although slightly lower, mainly due to the more strict cross-validation scheme. Our results suggest that the proposed sex estimation method is reasonably robust to secular change, since there was limited loss in classification accuracy between different chronological groups, despite the presence of secular change in stature of the Greek population during the examined period. The proposed method has been implemented as a function for the GNU Octave environment, named estimate_sex, which comprises a self-intuitive graphical user interface for facilitating sex estimation and is freely available under a suitable license. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature

Landmark based sex discrimination on the crania of archaeological Greek populations. A comparative study based on the cranial sexual dimorphism of a modern Greek population

The estimation of sex is a fundamental step for physical anthropologists. The present study confirms the presence of sexual dimorphism in cranial traits of a modern Greek population and produces sex predicting logistic regression equations, which are subsequently applied on the crania of archaeological Greek populations. This study uses 24 landmarks and 25 traits based on distance and angle measurements. Equations, were formulated for the cranium in whole, as well as, isolated cranial regions and single traits. The application of these equations on the archaeological Greek populations yielded an accuracy of classification over 70% in the sphenoid region, the maxilla and the cranium in whole and for three single traits. Hence, the results suggest that our equations based on the modern Greek population can successfully be used in sex prediction of archaeological Greek populations. © 2017 MAA

Testing the reliability of 3D-ID software in sex and ancestry estimation with a modern Greek sample

A primary concern in forensic anthropology, when reconstructing the biological profile of an unidentified individual is ancestry and sex estimation. The development of multivariate statistical methods and the assembly of large reference sample databases gave rise to the development of specialized computer software for sex and ancestry estimation. Among various such software, the 3D-ID is the only freely-available program that can handle missing values in the input dataset. The present study evaluates the reliability of 3D-ID in correctly classifying ancestry and sex of 158 test subjects from the Athens Collection, a documented Greek population sample. 3D-ID's classification performance was evaluated both separately and collectively for sex and ancestry. According to our results, the accuracy regarding sex estimation ranged from 74.05% to 86.7% for cases with unknown ancestry and reached 89.87% when testing within the Southeastern European reference group, whereas ancestry estimation accuracy reached 70.9% for correctly classifying the Greek individuals to European population groups. We conclude that 3D-ID software exhibits moderate reliability in ancestry estimation and adequate reliability in sex estimation. The Greek population seems to deviate from the 3D-ID software's reference samples and therefore caution should be taken in interpreting 3D-ID's results of unknown subjects, for which the software's reference sample database may not be representative. 3D-ID's guidelines for using 19-landmark configuration improves the accuracy of ancestry estimation and form variables should be preferred for sexing samples. © 2019 Elsevier B.V

Estimating sex using discriminant analysis of mandibular measurements from a modern greek sample

Background: Sex determination is an integral and fundamental step in biological profile construction. The mandible, which holds many dimorphic traits, can be useful for sex estimation in the forensic context. However, reliable sex estimation usually relies on population-specific mandibular morphometric criteria. To date, no such criteria are available for the modern Greek population, and the present study aims to fill this lack of data by identifying the most sexually dimorphic mandibular traits on a modern Greek population sample and reporting the discriminant functions that can most effectively be used for estimating sex. Materials and methods: For the purposes of this research, the 3D models of 194 adult mandibles (105 males and 89 females) from the Athens skeletal reference collection were used. A battery of 20 linear and 3 angular measurements was calculated from the 3D coordinates of anatomical landmarks positioned on the respective models and was analyzed by means of ANOVA and discriminant function analysis to investigate the expression of sexual dimorphism. Results: The coronoid height, theramus height, andthemaximum mandibular length are the most sexually dimorphic metric traits of the mandible, while the produced sex discriminant functions yielded cross-validated classification accuracy up to 85.7% for the Greek sample. Furthermore, most of the examined combinations of measurements exhibited the same sex discriminant capacity between different reference samples, despite their respective discriminant functions being population specific. Conclusions: Our findings indicate that the produced sex discriminant functions can be effectively used for sex determination in forensic casework and to verify the population specificity of these functions but also suggest that the expression of sexual dimorphism in the mandible shares certain features across different populations. © The Author(s)