Human identification: an investigation of 3D models of paranasal sinuses to establish a biological profile on a modern UK population.

Medical imaging is a valuable source for facilitating empirical research and provides an accessible gateway for developing novel forensic anthropological methods for analysis including 3D modelling. This is especially critical for the United Kingdom (UK), where methods developed from modern UK populations do not currently exist. This study introduces a new approach to assist in human identification using 3D models of the paranasal sinuses. The models were produced from a database of 500 modern CT scans provided by University College London Hospital. Linear measurements and elliptic Fourier coefficients taken from 1500 three-dimensional models across six ethnic groups assessed by one-way ANOVA and discriminant function analysis showed a range of classification rates with certain rates reaching 75-85.7% (p < 0.05) in correctly classifying age and sex according to size and shape. The findings offer insights into the potential for employing paranasal sinuses as an attribute for establishing the identification of unknown human remains in future crime reconstructions.

Sex estimation from virtual models: exploring the potential of stereolithic 3D crania models for morphoscopic trait scoring.

Modern computed tomography (CT) databases are becoming an accepted resource for the practice and development of identification methods in forensic anthropology. However, the utility of 3D models created using free and open-source visualization software such as 3D Slicer has not yet been thoroughly assessed for morphoscopic biological profiling methods where virtual methods of analysis are becoming more common. This paper presents a study that builds on the initial findings from Robles et al. (2020) to determine the feasibility of estimating sex on stereolithic (STL) 3D cranial models produced from CT scans from a modern, living UK population (n = 80) using equation 2 from the Walker's (2008) morphoscopic method. Kendall's coefficients of concordance (KCC) indicated substantial agreement using cranial features scores in an inter-observer test and a video-inter-observer test. Fleiss' Kappa scores showed moderate agreement (0.50) overall between inter-observer sex estimations, and for observer sex estimations in comparison to recorded sexes (0.56). It was found that novice users could virtually employ morphoscopic sex estimation methods effectively on STL 3D cranial models from modern individuals. This study also highlights the potential that digital databases of modern living populations can offer forensic anthropology. Key points: First example of Walker's (2008) method applied to a living UK population.Open-source software is a valuable resource for crime reconstruction approaches.Male scoring bias was observed in method application.Forensic anthropologists would benefit from virtual anthropology training to use and interpret 3D models.Digital databases offer more ethical, diverse, modern populations for future research.

Dehydration-Induced alterations to sharp force trauma on Sus domesticus radii.

Dehydration is a taphonomic process that affects nearly all skeletal remains, yet there is a dearth of evidence on this process within the forensic taphonomy literature. When considering the forensic implications of skeletal dehydration, a particular area of concern is sharp force trauma due to its global prominence in forensic cases. In an attempt to address these literature gaps and quantify the effects that dehydration has on skeletal elements, a controlled experiment subjected Sus domesticus (i.e., domestic pig) radii samples (n = 36) to laboratory-induced dehydration after they were inflicted with knife trauma. All samples were photographed pre- and post-dehydration; bone section and kerf mark length, width, and area were then measured from these photographs using ImageJ. Statistical analysis of pre- and post-dehydration samples showed that all measurements experienced significant (p ≤ 0.001) shrinkage, with bone sample area shrinking an average of 8.8 % and kerf mark area an average of 29.7 %. Alterations in length, width and area between the kerf marks and bone samples showed a weak, moderate, and strong correlation, respectively. These findings suggest that anthropological analysis may be affected by dehydration-induced shrinkage, highlighting the necessity of continued research into the effects of dehydration on skeletal trauma.

A multi-method assessment of 3D printed micromorphological osteological features.

The evaluation of 3D printed osteological materials has highlighted the difficulties associated with accurately representing fine surface details on printed bones. Moreover, there is an increasing need for reconstructions to be demonstrably accurate and reliable for use in the criminal justice system. The aim of this study was to assess the surface quality of 3D prints (n = 9) that presented with micromorphological alterations from trauma, taphonomy and pathology processes. The archaeological bones were imaged using micro-CT scanning and 3D printed with selective laser sintering (SLS) printing. A multi-method experimental approach subsequently identified: (1) the 3D printed bones to be metrically accurate to within 1.0 mm; (2) good representation of micromorphological surface features overall, albeit with some loss of intricate details, depths, and fine textures that can be important for visual processing; (3) five of the nine 3D printed bones were quantitatively scored as accurate using the visual comparison method; and, (4) low mesh comparison distances (± 0.2 mm) between the original models and the digitised 3D print models. The findings offer empirical data that can be used to underpin 3D printed reconstructions of exhibits for use in courts of law. In addition, an adaptable pathway was presented that can be used to assess 3D print accuracy in future reconstructions.

An assessment of the reliability of cut surface characteristics to distinguish between hand-powered reciprocating saw blades in cases of experimental dismemberment.

Criminal dismemberment is most commonly committed with a variety of hand-powered saws. These saws leave characteristic marks upon the bone that can assist in the identification of the weapon utilized. The current study provides frequencies of presentation of ten cut surface characteristics and examines intra- and interindividual variation between three hand-powered reciprocating saws. Pig radii were used as a proxy for human remains. 42 cut surfaces were created with three hand-powered reciprocating saws by the same researcher. Cut surface characteristics were assessed macroscopically, microscopically and with Scanning Electron Microscope (SEM), as well as photographed with Reflectance Transformation Imaging (RTI). Cut surface polish is the only characteristic that demonstrates consistently significant difference between saws. Five characteristics demonstrate some variation between blades: entrance shaving, breakaway spurs, breakaway notches, pull-out striae, and tooth hop. Four characteristics demonstrate no difference between blades: cut surface striation shape, cut surface striation regularity, harmonics, and exit chipping. Tooth hop is the most reliable characteristic for differentiating between blades in this study, while pull-out striae demonstrates high intra-individual variability and a low frequency of presentation making it unreliable for differentiating between saw blades. Cut surface striations, exit chipping, and breakaway spurs occurred with the highest frequencies and were reliable for determining direction of blade progress and blade stroke, but were not reliable for differentiating between saw blades. Harmonics were absent. Further research is necessary to create large databases of known saw mark examples with known intra- and interindividual variability rates and error rates.

Reflectance Transformation Imaging (RTI) for the Documentation of Saw Mark Characteristics.

Photography is widely accepted as a means of forensic case documentation and evaluation. In cases of criminal dismemberment digital microscopy is commonly used to assess marks left on the bone. Reflectance transformation imaging (RTI) is a computational photography technique which documents and enhances the three-dimensional (3D) reflectance properties of the surface of an object. RTI has primarily been used in the cultural heritage sector but has recently transitioned into forensic science. This study examines the use of RTI for the documentation and presentation of cut surface characteristics on fully sectioned long bones. Juvenile pig radii were bisected using three different handsaws, chosen as handsaws are the most common implement used in criminal dismemberments. The resulting 42 cut surfaces were then documented with a digital microscope and RTI. Four rendering modes were applied to the default RTI image, with diffuse gain being the most beneficial to accentuate cut surface features. Although great care must be taken when obtaining the photographic sequences necessary for detailed RTI analysis, RTI is relatively inexpensive, expeditious, and easy to use, and creates highly detailed, virtually interactive images. RTI may not replace microscopic methods of saw mark analysis, however could prove useful for the documentation, image sharing, and presentation of forensic evidence.

Socioeconomic differences in diet: An isotopic examination of post-Medieval Chichester, West Sussex.

OBJECTIVES: Historical evidence suggests that social hierarchy pervaded all aspects of society in post-Medieval England. This study uses stable isotope analysis to explore the extent to which socioeconomic status and sex affected the dietary habits of the inhabitants of post-Medieval Chichester. MATERIALS AND METHODS: Stable carbon and nitrogen isotope ratios were measured on 40 human burials from the post-Medieval site of St. Michael's Litten (Chichester, West Sussex, England). Samples were selected from three burial types that denoted differing socioeconomic status with roughly equal numbers of males and females: tomb burials (n = 13) for high-status; single coffin burials (n = 14) for middle-status; and shroud burials (n = 13) for low-status individuals. RESULTS: The data showed a largely terrestrial diet with the possibility of some inclusion of marine resources. The isotope results indicate significant variation in the consumption of terrestrial meat (and marine protein) between high-status tomb burials and coffin and shroud burials, showing that socioeconomic status likely played a role in daily dietary patterns. However, the isotope data suggest sex did not influence an individual's diet. DISCUSSION: These results mirror trends established in status-based studies from elsewhere in post-Medieval England. However, notably absent from the data is evidence for significant marine resource consumption, which is a well-established dietary trend of the late Medieval and early post-Medieval periods. These results indicate post-Medieval Chichester was a socially stratified society with clear implications that the diet of higher status individuals differed significantly from lower status.

Forensic Gait Analysis and Recognition: Standards of Evidence Admissibility.

Gait is one biological characteristic which has attracted strong research interest due to its potential use in human identification. Although almost two decades have passed since a forensic gait expert has testified to the identity of a perpetrator in court, the methods remain insufficiently robust, considering the recent paradigm shift witnessed in the forensic science community regarding quality of evidence. In contrast, technological advancements have taken the lead, and research into automated gait recognition has greatly surpassed forensic gait analysis in terms of the size of acquired datasets and demographic variability of participants, tested variables, and statistical evaluation of results. Despite these advantages, gait recognition presents with different problems which are yet to be resolved. Therefore, courts should treat gait evidence with caution, as they should any other form of evidence originating from disciplines without fully established codes of practice, error rates, and demonstrable applications in forensic scenarios.

A Preliminary Investigation into the Accuracy of 3D Modeling and 3D Printing in Forensic Anthropology Evidence Reconstruction.

There is currently no published empirical evidence-base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court. In this study, human bones (n = 3) scanned using computed tomography were reconstructed as virtual 3D models (n = 6), and 3D printed using six commercially available printers, with osteometric data recorded at each stage. Virtual models and 3D prints were on average accurate to the source bones, with mean differences from -0.4 to 1.2 mm (-0.4% to 12.0%). Interobserver differences ranged from -5.1 to 0.7 mm (-5.3% to 0.7%). Reconstruction and modeling parameters influenced accuracy, and prints produced using selective laser sintering (SLS) were most consistently accurate. This preliminary investigation into virtual modeling and 3D printer capability provides a novel insight into the accuracy of 3D printing osteological samples and begins to establish an evidence-base for validating 3D printed bones as demonstrative evidence.

Extensive periosteal new bone formation in a skeleton from post-Medieval Chichester, England: A probable case of metastatic prostatic carcinoma.

An elderly male skeleton from a site in Chichester, UK, was found with a widespread periosteal reaction, principally affecting the axial skeleton and the pelvis. Radiography showed the presence of sclerosing infiltrates, mainly involving the lumbar vertebrae and pelvis. The differential diagnosis is discussed, reaching the conclusion that hypertrophic osteo-arthopathy (HOA) is the only reasonable alternative condition likely to produce such a widespread periosteal reaction as found here. HOA does not produce secondary deposits in the skeleton, however, and we conclude that his is most likely a case of prostatic carcinoma.

The suitability of visual taphonomic methods for digital photographs: An experimental approach with pig carcasses in a tropical climate.

In the context of increased scrutiny of the methods in forensic sciences, it is essential to ensure that the approaches used in forensic taphonomy to measure decomposition and estimate the postmortem interval are underpinned by robust evidence-based data. Digital photographs are an important source of documentation in forensic taphonomic investigations but the suitability of the current approaches for photographs, rather than real-time remains, is poorly studied which can undermine accurate forensic conclusions. The present study aimed to investigate the suitability of 2D colour digital photographs for evaluating decomposition of exposed human analogues (Sus scrofa domesticus) in a tropical savanna environment (Hawaii), using two published scoring methods; Megyesi et al., 2005 and Keough et al., 2017. It was found that there were significant differences between the real-time and photograph decomposition scores when the Megyesi et al. method was used. However, the Keough et al. method applied to photographs reflected real-time decomposition more closely and thus appears more suitable to evaluate pig decomposition from 2D photographs. The findings indicate that the type of scoring method used has a significant impact on the ability to accurately evaluate the decomposition of exposed pig carcasses from photographs. It was further identified that photographic taphonomic analysis can reach high inter-observer reproducibility. These novel findings are of significant importance for the forensic sciences as they highlight the potential for high quality photograph coverage to provide useful complementary information for the forensic taphonomic investigation. New recommendations to develop robust transparent approaches adapted to photographs in forensic taphonomy are suggested based on these findings.

Cascading Bias of Initial Exposure to Information at the Crime Scene to the Subsequent Evaluation of Skeletal Remains.

Thirty-eight participants took part in a study that investigated the potential cascading effects of initial exposure to extraneous context upon subsequent decision-making. Participants investigated a mock crime scene, which included the excavation of clandestine burials that had a male skeletal cast dressed either in female or gender neutral clothing. This was followed by a forensic anthropological assessment of the skeletal remains, with a control group assessing the same male skeletal cast without any clothing context. The results indicated that the sex assessment was highly dependent upon the context in which participants were exposed to prior to the analysis. This was especially noticeable in the female clothing context where only one participant determined the male skeletal cast to be male. The results demonstrate the importance of understanding the role of context in forensic anthropology at an early stage of an investigation and its potential cascading effect on subsequent assessments.

Extensive unusual lesions on a large number of immersed human victims found to be from cookiecutter sharks (Isistius spp.): an examination of the Yemenia plane crash.

Accurate determination of the origin and timing of trauma is key in medicolegal investigations when the cause and manner of death are unknown. However, distinction between criminal and accidental perimortem trauma and postmortem modifications can be challenging when facing unidentified trauma. Postmortem examination of the immersed victims of the Yemenia airplane crash (Comoros, 2009) demonstrated the challenges in diagnosing extensive unusual circular lesions found on the corpses. The objective of this study was to identify the origin and timing of occurrence (peri- or postmortem) of the lesions.A retrospective multidisciplinary study using autopsy reports (n = 113) and postmortem digital photos (n = 3 579) was conducted. Of the 113 victims recovered from the crash, 62 (54.9 %) presented unusual lesions (n = 560) with a median number of 7 (IQR 3 ∼ 13) and a maximum of 27 per corpse. The majority of lesions were elliptic (58 %) and had an area smaller than 10 cm2 (82.1 %). Some lesions (6.8 %) also showed clear tooth notches on their edges. These findings identified most of the lesions as consistent with postmortem bite marks from cookiecutter sharks (Isistius spp.). It suggests that cookiecutter sharks were important agents in the degradation of the corpses and thus introduced potential cognitive bias in the research of the cause and manner of death. A novel set of evidence-based identification criteria for cookiecutter bite marks on human bodies is developed to facilitate more accurate medicolegal diagnosis of cookiecutter bites.

Developing the use of Structure-from-Motion in mass grave documentation.

Methods for mass-grave documentation have changed markedly since the first forensic investigations nearly 70 years ago. Recently, however, there has been little advancement in developing new and better methodology, especially when compared to other forensic disciplines and even within traditional archaeology. This paper proposes a new approach, using 3D modelling for the documentation and eventual analysis of mass-graves. Structure-from-Motion (SfM), which creates digital 3D models from a set of still photographs, was tested on a small, simulated mass grave. The results of this test suggest that the method offers resolution previously unavailable to mass-grave investigators, and facilitates stronger analytical potential than the more traditional methods. Further tests are needed to validate these methods, but these initial findings are promising and their application could enhance our knowledge of mass grave dynamics.

Case report: A giant calcified uterus, likely due to benign leiomyoma.

During the 2011 excavation of the site of St. Michael's Litten, in Chichester, England, a female skeleton, dating to the post-Medieval period (1550-1850), with a large, unidentified pelvic mass was uncovered. The mass measured 16.4H×19.0W×24.3L and was 66cm in its greatest circumference; it weighed 3.32kg. The skeleton presented with established osteoporosis and was estimated to be of an advanced age. The analytic methodology used to evaluate the mass was based on that of Kramar et al. (1983). Considering the results of these analyses, and through an extensive search of the relevant medical, historical and archaeological literature, it was determined that this mass was likely a neoplasm of reproductive origin, and was further defined as a calcified uterus containing a number of leiomyomas. To date, this is the largest of its kind ever found archaeologically.

Changes in mandibular dimensions during the mediaeval to post-mediaeval transition in London: a possible response to decreased masticatory load.

OBJECTIVES: Biomechanical forces, such as those produced during mastication, are considered a primary agent in stimulating craniofacial growth and development. There appears to be a strong connection between the strength of the masticatory muscles and the dimensions of the craniofacial complex, with changes in biomechanical force and muscular strength influencing and altering the underlying bony tissues. This is markedly apparent in the mandible and it is possible to infer that changes to mandibular form are due in part to dietary changes. This study aims to investigate this idea by using an archaeological sample from a period that experienced important dietary changes as a result of the Industrial Revolution. DESIGN: 279 skeletons from the mediaeval and post-mediaeval periods in London were selected for analysis, and a detailed metric examination of each mandible was carried out. RESULTS: Males and females were analysed separately and statistically significant reductions were observed in nearly all post-mediaeval measurements. This effect was most pronounced in the areas of the mandible associated with masticatory muscles attachment, including the gonial angle, ramus height and width, bi-gonial breadth and bi-condylar breadth. CONCLUSIONS: These recorded changes in mandibular morphology of mediaeval and post-mediaeval Londoners are most likely the result of a shift in diet (and associated decrease in masticatory function) observed in the period surrounding the Industrial Revolution.

TMJ osteoarthritis: a new approach to diagnosis.

Disorders of the temporomandibular joint (TMJ), including TMJ osteoarthritis (TMJ OA), are the topic of intensive clinical research; however, this is not the case in the archaeological literature, with the majority of work on the subject ceasing with the early 1990s. The methods employed in the diagnosis of TMJ OA within the archaeological work appear nonrepresentative of the disease and may have led to erroneous assumptions about the pattern and prevalence of OA. This current work presents a new method for evaluating OA specifically for the TMJ, considering both the biomechanics of the joint and the mechanisms of the disease. Totally, 496 specimens (including a group of modern documented specimens) were analyzed for the presence of TMJ OA using the following criteria: eburnation, osteophytes (marginal and new bone on joint surface), porosity, and alteration to joint contour. The results suggest that eburnation occurs rarely in the TMJ, so should not be used as an exclusive criterion. Rather a combination of at least two of the other criteria should be used, with osteophytes and porosity occurring the most frequently on both the mandibular condyle and articular eminence. Additionally, the prevalence of TMJ OA in the modern assemblage was similar to that observed in current clinical research, suggesting that the method employed here was able to produce a reasonable approximation of what is found in contemporary living populations.