Osteometric Sorting

This study reviews recent advances in osteometric, genetic, geochemical, and digital modeling applications since 2014 to demonstrate the expanded range of analyses and skeletal elements that can be used to separate individuals from commingled contexts. While traditional methods remain foundational to commingling resolution, new advances allow increased individuation, identification of human versus non-human remains, and an amplified scale of assemblages that can be analyzed.

Accurate sorting of commingled human remains comprises a fundamental requirement for all further anthropological analyses. The lower limb bones are particularly important for reconstructing biological profiles. This study introduces a metric technique for sorting these elements using eight standard anthropological measurements and 222 adult individuals from Greece. The bones utilized were the os coxae, the femora, the tibiae and the tali. Simple regression analyses were used to develop functions for reassociating articulating bones, providing strong correlations (r = 0.74-0.95, p-value <0.05) and high coefficients of determination (r =0.54-0.91). Blind tests demonstrated that combining metric and morphoscopic techniques provides an excellent sorting accuracy for the hip and knee joints (ten of ten individuals), allowing for a reliable reassociation between a sex and age indicator (os coxae) and a body size indicator (femur). Overall, these results indicate the high value of metri...

In a commingled context, assessing that a talus and a calcaneus correspond to the same individual could become a primary step for accurately sorting human remains. For this purpose, the lengths and widths of the trochlea, posterior calcaneal articular surface, and posterior talar articular surface were measured in 197 individuals (105 males, 92 females) from the Athens Collection. A total of 12 highly accurate equations for reassociating tali and calcanei were developed, using simple and multiple linear regression analysis and they were found to be suitable for sorting commingled human remains. Bilateral asymmetry and sex did not have an effect on the accuracy of the method.

The major upper limb skeletal elements (scapulae, humeri, ulnae and radii) are frequently utilized for sex determination and stature estimation. Consequently, in forensic cases that involve commingled remains, it is crucial to reassociate the aforementioned bones and attribute them to the right individual. The aim of the present study is to develop simple and multiple regression equations for sorting commingled human skeletal elements of the upper limb. In that context, ten common anthropological linear measurements of the articular surfaces of scapulae, humeri, ulnae, and radii were performed on 222 adult skeletons from the Athens Collection. The functions developed for sorting adjoining bones presented a strong positive linear relationship (r=0.69-0.93, p<0.05). The values of the determination coefficient statistics (r 2 =0.47-0.86) were found to be high and those of the standard errors of the estimate were found to be low (SEE=0.88-1.61). Blind tests indicated that when metric and morphoscopic sorting techniques are combined, a reliable sorting of the skeletal elements of the upper limbs is possible.

In a commingled context, assessing that a talus and a calcaneus correspond to the same individual could become a primary step for accurately sorting human remains. For this purpose, the lengths and widths of the trochlea, posterior calcaneal articular surface, and posterior talar articular surface were measured in 197 individuals (105 males, 92 females) from the Athens Collection. A total of 12 highly accurate equations for reassociating tali and calcanei were developed, using simple and multiple linear regression analysis and they were found to be suitable for sorting commingled human remains. Bilateral asymmetry and sex did not have an effect on the accuracy of the method.

Statistical tests that compare classification algorithms are univariate and use a single performance measure, e.g., misclassification error, $F$ measure, AUC, and so on. In multivariate tests, comparison is done using multiple measures simultaneously. For example, error is the sum of false positives and false negatives and a univariate test on error cannot make a distinction between these two sources, but a 2-variate test can. Similarly, instead of combining precision and recall in $F$ measure, we can have a 2-variate test on (precision, recall). We use Hotelling&#39;s multivariate $T^2$ test for comparing two algorithms, and when we have three or more algorithms we use the multivariate analysis of variance (MANOVA) followed by pairwise post hoc tests. In our experiments, we see that multivariate tests have higher power than univariate tests, that is, they can detect differences that univariate tests cannot. We also discuss how multivariate analysis allows us to automatically extrac...

Physical fit examinations have long played a critical role in forensic science, particularly in the trace evidence, toolmark, and questioned documents disciplines. Specifically, in trace evidence, physical fits arise in various instances such as separated pieces of duct tape, torn textile fragments, and fractured polymeric items to name a few. The case report and research basis for forensic physical fit dates to the late 1700s and varies by material type. Three main areas of physical fit appear within the literature: case reports, fractography studies, and quantitative assessment of a fracture fit. A strong foundation within the discipline lies in case reports, articles demonstrating occurrences of physical fit the authors have experienced in their laboratories. Fractography research offers information about the fracturing mechanism of a given material for purposes of identifying a potential breaking source. Also, fractography studies demonstrate variation in fracture morphology per material types, with a qualitative basis for comparison and reporting. The current shift in the research appears to be more quantitative or performance-based, assessing the error rates associated with physical fit examinations, the application of likelihood ratios as a means to determine evidential weight, probabilistic interpretations of large sample sets, and the implementation of automatic edge-detection algorithms to support the examiner's expert opinion. This review aims to establish the current state of physical fit research through what has been accomplished, the limitations faced due to the unpredictable nature of casework, and the future directions of the discipline. In addition, current practice in the field is evaluated through a review of standard operating procedures.

In a commingled context, assessing that a talus and a calcaneus correspond to the same individual could become a primary step for accurately sorting human remains. For this purpose, the lengths and widths of the trochlea, posterior calcaneal articular surface, and posterior talar articular surface were measured in 197 individuals (105 males, 92 females) from the Athens Collection. A total of 12 highly accurate equations for reassociating tali and calcanei were developed, using simple and multiple linear regression analysis and they were found to be suitable for sorting commingled human remains. Bilateral asymmetry and sex did not have an effect on the accuracy of the method.

The major upper limb skeletal elements (scapulae, humeri, ulnae and radii) are frequently utilized for sex determination and stature estimation. Consequently, in forensic cases that involve commingled remains, it is crucial to reassociate the aforementioned bones and attribute them to the right individual. The aim of the present study is to develop simple and multiple regression equations for sorting commingled human skeletal elements of the upper limb. In that context, ten common anthropological linear measurements of the articular surfaces of scapulae, humeri, ulnae, and radii were performed on 222 adult skeletons from the Athens Collection. The functions developed for sorting adjoining bones presented a strong positive linear relationship (r = 0.69-0.93, p < 0.05). The values of the determination coefficient statistics (r 2 = 0.47-0.86) were found to be high and those of the standard errors of the estimate were found to be low (SEE = 0.88-1.61). Blind tests indicated that when metric and morphoscopic sorting techniques are combined, a reliable sorting of the skeletal elements of the upper limbs is possible.

This paper is the introduction to the special issue on commingled human remains analysis within forensic anthropology. It provides an overview of the articles in this special issue of Forensic Anthropology and the impetus behind the creation of the
special issue.

A common problem in forensic anthropology is the pair‐matching of left and right bone antimeres. Several osteometric sorting models have been proposed in the last 20 years, with a recent acceleration in new methodological articles bringing sometimes contradictory results or recommendations. These debates demonstrate the need for a statistical tool both accurate and easily applicable by the final user.

We present here an approach based on quadratic discriminant analysis (QDA). This approach is evaluated on antimeric pairs of humeri and femora from the openly available Goldman Data Set, and compared to two classical and previously published methods for osteometric pair‐matching, based respectively on linear regressions and t‐tests. It is shown that QDA globally outperforms existing solutions for reassociating those long bones, in particular by rejecting fewer true bone pairs at the classical α level of 0.10. The accuracy of all three methods is analyzed through receiver operating characteristic (ROC) curves to assess the influence of the choice of a decision threshold. The application on archaeological commingled remains of pair‐matching models learned on a modern reference multipopulation sample is discussed. Finally, an R package containing the functions used for this study, bonepairs, is publicly available online. This ensures the full replicability of results and an easy use of the new method introduced here.

Accurate sorting of commingled human remains comprises a fundamental requirement for all further anthropological analyses. The lower limb bones are particularly important for reconstructing biological profiles. This study introduces a metric technique for sorting these elements using eight standard anthropological measurements and 222 adult individuals from Greece. The bones utilized were the os coxae, the femora, the tibiae and the tali. Simple regression analyses were used to develop functions for reassociating articulating bones, providing strong correlations (r = 0.74–0.95, p-value <0.05) and high coefficients of determination (r 2 =0.54–0.91). Blind tests demonstrated that combining metric and morphoscopic techniques provides an excellent sorting accuracy for the hip and knee joints (ten of ten individuals), allowing for a reliable reassociation between a sex and age indicator (os coxae) and a body size indicator (femur). Overall, these results indicate the high value of metric methods in sorting commingled human remains. The presence of commingled human skeletal remains is a fundamental issue in anthropological studies, as it is the natural outcome of mass disasters, mass graves, or secondary burials. Regardless of the context, the accurate sorting of commingled remains is the basis for their further anthropological analysis. In a forensic context, it comprises the primary step for reconstructing the identity of unidentified human skeletal remains. In bioarcheological contexts, it can provide crucial demographic knowledge on the ancient population under study (1). Some of the most widely utilized techniques of sorting com-mingled human remains are entirely based on naked-eye observation. Their main criteria involve the morphological compatibility between two adjoining articular surfaces as well as the presence of similar morphological traits between two or more skeletal elements (i.e., texture, coloration, density). This similarity is due to various taphonomic or pathological factors which had a similar effect on multiple bones of the same skeleton (2,3). However, it should be noted that, as far as taphonomic factors are concerned, these often have similar effects on the entire assemblage (involving multiple individuals). Consequently, they may not always comprise an accurate criterion for sorting bones per individual. Moreover, the applicability and accuracy of these methods are influenced by an increased subjectivity in determining the degree of similarity and compatibility between two skeletal elements. These techniques also require the comparison of compatibility across all possible pairs of bones found in a commingled context, which can be an extremely time-consuming task in cases of large-scale commin-gling. Furthermore, this concept entirely relies on the assumption that both bones of each individual are actually preserved and recovered from the field. These limitations can be greatly reduced through the systematic development of original and more objective methods for sorting commingled human remains. If these techniques are proven to be of high precision and accuracy, they could substantially increase the level of certainty in associating a series of bone elements with the same individual. For this purpose, a previous research successfully combined morphoscopic and metric methodology to reassociate the skeletal elements of the subtalar joint (4). The regression equations produced gave a range of possible talus-calcaneus matches, and the morphoscopic evaluation gave the final match. It is crucial for the metric method to be applied first as it considerably reduces the number of possible matches. The method is reported to have rather accurate predictions and to be applicable on mixed-sex samples comprising specimens of both anatomical sides. In up to 95.98% of the cases, the difference between the real and the predicted value ranged between 0 and 2 mm. Finally, a blind test of a sample involving 20 individuals was performed, which presented a very high rate of correct sorting. Particularly in 89.5% for the left and 88.9% for the right skeletal elements, the examined bones were correctly attributed to the corresponding individual.

In a commingled context, assessing that a talus and a calcaneus correspond to the same individual could become a primary step for accurately sorting human remains. For this purpose, the lengths and widths of the trochlea, posterior calcaneal articular surface, and posterior talar articular surface were measured in 197 individuals (105 males, 92 females) from the Athens Collection. A total of 12 highly accurate equations for reassociating tali and calcanei were developed, using simple and multiple linear regression analysis and they were found to be suitable for sorting commingled human remains. Bilateral asymmetry and sex did not have an effect on the accuracy of the method.

Several osteometric approaches to estimate physical side dominance have been reported recently. However, the reliability of these methods is far from satisfactory for forensic applications. Here, we report a very significant side-to-side difference of the humeri observed radiographically in an individual with unilateral hand amputation, and extend the study to a more comprehensive population of untraumatized individuals. Specifically, the left-hand amputated male and additional 20 individuals (9 females, 11 males; 16 adults, 4 matures) recovered from the same medieval graveyard, were subjected both to osteometric measurements and single-shot digital x-ray screening of the bilateral bones. The region of interest (ROI) for measurement of mean grayscale values, correlating with the mineral density, was defined distal from the midpoint of the humeri, sized to: ROIwidth=250Px; ROIheight=(Humerusmaximum length/366)x200Px. Standardized bilateral asymmetry (SBA) was calculated by the genera...

Morphometric analysis of footprints is a classic means for orthopedic diagnosis. In forensics and physical anthropology, it is commonly used for the estimation of stature and body mass. We studied individual variation and sexual dimorphism of foot dimensions and footprint shape by a combination of classic foot measurements and geometric morphometric methods. Left and right feet of 134 healthy adult males and females were scanned twice with a 3D optical laser scanner, and stature as well as body mass were recorded. Foot length and width were measured on the 3D scans. The 2D footprints were extracted as the plantar-most 2 mm of the 3D scans and measured with 85 landmarks and semilandmarks. Both foot size and footprint shape are sexually dimorphic and relate to stature and body mass. While dimorphism in foot length largely results from dimorphism in stature, dimorphism in footprint shape partly owes to the dimorphism in BMI. Stature could be estimated well based on foot length (R(2)  =...

Commingling refers to the situation where more than one individual is represented and have become mixed together; the sorting of individuals in a commingled assemblage is critical in post conflict situations such as mass graves. There are strong correlations among the sizes of bones. If someone has a large humerus, you can expect that they will have a large femur. Osteometric sorting removes the subjective judgment and relies solely on statistics to make the decision. Osteometric sorting uses measurements to compare size differences between two skeletal elements and the same elements in a reference population. Segregation decisions are made by testing the null hypothesis that the two specimens of interest are of a similar size and shape to have originated from a single individual. In this study, the Piggot ossuary (31CR14) is employed to represent a large-scale commingling.