RESUMO
The expansion of people speaking Bantu languages is the most dramatic demographic event in Late Holocene Africa and fundamentally reshaped the linguistic, cultural and biological landscape of the continent1-7. With a comprehensive genomic dataset, including newly generated data of modern-day and ancient DNA from previously unsampled regions in Africa, we contribute insights into this expansion that started 6,000-4,000 years ago in western Africa. We genotyped 1,763 participants, including 1,526 Bantu speakers from 147 populations across 14 African countries, and generated whole-genome sequences from 12 Late Iron Age individuals8. We show that genetic diversity amongst Bantu-speaking populations declines with distance from western Africa, with current-day Zambia and the Democratic Republic of Congo as possible crossroads of interaction. Using spatially explicit methods9 and correlating genetic, linguistic and geographical data, we provide cross-disciplinary support for a serial-founder migration model. We further show that Bantu speakers received significant gene flow from local groups in regions they expanded into. Our genetic dataset provides an exhaustive modern-day African comparative dataset for ancient DNA studies10 and will be important to a wide range of disciplines from science and humanities, as well as to the medical sector studying human genetic variation and health in African and African-descendant populations.
Assuntos
DNA Antigo , Emigração e Imigração , Genética Populacional , Idioma , Humanos , África Ocidental , Conjuntos de Dados como Assunto , República Democrática do Congo , DNA Antigo/análise , Emigração e Imigração/história , Efeito Fundador , Fluxo Gênico/genética , Variação Genética/genética , História Antiga , Idioma/história , Linguística/história , Zâmbia , Mapeamento GeográficoRESUMO
Morphological analysis in forensic facial comparison was recently validated for judicial use. However, no image quality assurance systems exist for this purpose, despite image triage being considered the best practice approach. Hence, this study aimed at testing a semi-quantitative scoring method to assess image quality and investigated facial image resolution and lighting quality quantitatively in a context of forensic facial comparison. For this purpose, 400 facial comparison photographic and CCTV image pools developed from the Wits Face Database were used. These facial images were analysed in prior studies that investigated the validity of morphological analysis. A semi-quantitative image quality scoring system was adapted and tested on the above sample and compared across correct and incorrect matches obtained as part of previous studies using a logistic regression model. In addition, facial images were cropped to the closest pixel comprising the face, head and neck areas; then, a face-to-image pixel proportion was calculated as an estimator of resolution quality; and pixel exposure qualities were obtained to be compared to facial comparison outcomes. Ideal and high image quality scores were related to correctness of matches, while low-quality scores were related to incorrect matches. High pixel proportions were related to true matches and low exposure was related to false positives, while high exposure was related to false negatives. These results suggest that an easy method for image triage could be employed by scoring image quality. Quantitative measures should be investigated further for thresholding quality suitability for confidence of facial comparisons.
Assuntos
Face , Fotografação , Humanos , Face/anatomia & histologia , Face/diagnóstico por imagem , Masculino , Feminino , Processamento de Imagem Assistida por Computador/métodos , Modelos Logísticos , Iluminação , Bases de Dados Factuais , AdultoRESUMO
Age assessment of migrants is crucial, particularly for unaccompanied foreign minors, a population facing legal, social, and humanitarian challenges. Despite existing guidelines, there is no unified protocol in Europe for age assessment.The Forensic Anthropology Society of Europe (FASE) conducted a comprehensive questionnaire to understand age estimation practices in Europe. The questionnaire had sections focusing on the professional background of respondents, annual assessment numbers, requesting parties and reasons, types of examinations conducted (e.g., physical, radiological), followed protocols, age estimation methods, and questions on how age estimates are reported.The questionnaire's findings reveal extensive engagement of the forensic community in age assessment in the living, emphasizing multidisciplinary approaches. However, there seems to be an incomplete appreciation of AGFAD guidelines. Commonalities exist in examination methodologies and imaging tests. However, discrepancies emerged among respondents regarding sexual maturity assessment and reporting assessment results. Given the increasing importance of age assessment, especially for migrant child protection, the study stresses the need for a unified protocol across European countries. This can only be achieved if EU Member States wholeheartedly embrace the fundamental principles outlined in EU Directives and conduct medical age assessments aligned with recognized standards such as the AGFAD guidelines.
Assuntos
Refugiados , Migrantes , Criança , Humanos , Menores de Idade , Europa (Continente) , Antropologia Forense , Determinação da Idade pelo EsqueletoRESUMO
An age-at-death estimation method using the first rib may be particularly advantageous as this rib is relatively easy to identify, not easily damaged postmortem, and associated with less mechanical stresses compared to other age indicators. Previously, mixed results have been achieved using the first rib to estimate age-at-death. This study aimed to develop and test an age-at-death estimation method using the first rib. An identified modern black South African sample of 260 skeletons were used to collect age-related data from the first rib. Multiple linear regression analysis equations were created from this data for male, female, and combined samples. When tested on a hold-out sample, equations generated mean inaccuracies of 7-13 years for point estimates. The 95% confidence intervals contained the true age in 11-33% of individuals depending on the equation used, but wider intervals generated using 95% prediction intervals contained true ages for 100% of individuals. Point estimate inaccuracies are comparable to other age-at-death estimation methods and may be useful if single indicator estimation is unavoidable in the case of missing or damaged bones. However, combined methods that use indicators from many areas of the skeleton are preferable and may reduce interval widths.
Assuntos
Determinação da Idade pelo Esqueleto , Antropologia Forense , Adulto , Humanos , Masculino , Feminino , África do Sul , Antropologia Forense/métodos , Determinação da Idade pelo Esqueleto/métodos , Costelas/anatomia & histologia , População NegraRESUMO
The mathematical method which will achieve the most accurate and precise age-at-death estimate from the adult skeleton is often debated. Some research promotes Bayesian analysis, which is widely considered better suited to the data construct of adult age-at-death distributions. Other research indicates that methods with less mathematical complexity produce equally accurate and precise age-at-death estimates. One of the advantages of Bayesian analysis is the ability to systematically combine multiple indicators, which is reported to improve the age-at-death estimate. Few comparisons exist between Bayesian analysis and less complex mathematical models when considering multiple skeletal indicators. This study aims to evaluate the performance of a Bayesian approach compared to a phase-based averaging method and linear regression analysis using multiple skeletal indicators. The three combination methods were constructed from age-at-death data collected from 330 adult skeletons contained in the Raymond A Dart and Pretoria Bone Collections in South Africa. These methods were tested and compared using a hold-out sample of 30 skeletons. As is frequently reported in literature, a balance between accuracy and precision was difficult to obtain from the three selected methods. However, the averaging and regression analysis methods outperformed the Bayesian approach in both accuracy and precision. Nevertheless, each method may be suited to its own unique situation-averaging to inform first impressions, multiple linear regression to achieve statistically defensible accuracies and precisions and Bayesian analysis to allow for cases where category adjustments or missing indicators are necessary.
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Osso e Ossos , Modelos Teóricos , Adulto , Teorema de Bayes , Humanos , Análise de Regressão , África do SulRESUMO
Victims of violent crime often have evidence of sharp force trauma (SFT) which needs to be examined to accurately investigate these cases. The abilities of CTs, X-rays, and Lodox to detect skeletal SFT defects and the minimum number of impacts were assessed, as were their abilities to macroscopically interpret SFT with the aim of identifying the class of weapon used. Ten pigs were, post-mortem, stabbed using a kitchen knife on one side of the body and chopped using a panga on the other side. They were then scanned and macerated. The number of SFT defects, type of SFT, and minimum number of impacts identifiable osteologically were recorded, as well as when using each imaging modality. CTs were most sensitive for detecting stab and chop defects (56.7% and 78.3%, respectively) and the minimum number of impacts (82.8%), while X-rays were least sensitive (17.2% for stab wounds, 46.5% for chop marks, and 43.5% for impacts). Lodox detected 26.8% of stab defects, 59.3% of chop marks, and 58.4% of impacts. The type of SFT for more than 70.0% of identified defects was correctly classified using all methods, while only Lodox had moderate sensitivities for stab wounds (52.4%). When radiological assessments of skeletal SFT are required, CTs should be performed, but Lodox can be used as an alternative. However, dry bone analyses still produce the best results and should be performed whenever possible. Macroscopic interpretations of skeletal SFT to broadly determine the class of weapon used is possible radiologically.
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Ferimentos Perfurantes , Animais , Radiografia , Sensibilidade e Especificidade , Suínos , Tomografia Computadorizada por Raios X/métodos , Ferimentos Perfurantes/diagnóstico por imagem , Raios XRESUMO
Between the ever-increasing availability of surveillance evidence and expert-based forensic facial comparison being considered admissible in court, confirming its validity is paramount. Facial comparison is most commonly conducted using morphological analysis (MA), a largely untested feature-based approach. This study aimed at validating the current recommended practice of MA in both standardised and suboptimal surveillance samples. Face pools of 175 South African males were compiled with a series of facial photographs, using images from the Wits Face Database. The first 75 face pools consisted of wildtype (unstandardised) high-quality target photographs, while the remaining 100 face pools consisted of suboptimal closed-circuit television (CCTV) target images. Target images were compared to high-quality standardised photographs. Face pools were analysed using the Facial Identification Scientific Working Group's guidelines and feature list. Confusion matrices were used to determine the performance of MA in each cohort. MA was found highly accurate (chance-corrected accuracy (CCA): 99.1%) and reliable (κ = 0.921) in the photographic sample and less accurate (CCA: 82.6%) and reliable (κ = 0.743), in the CCTV sample. Higher false-positive and false-negative rates were noted for the CCTV sample, with the majority of errors resulting in false-negative outcomes. The decreased performance in the CCTV sample was attributed to various factors including image quality, angle of recording and lighting. Other studies testing facial comparison identified lower accuracies and reliability across various conditions. Better performance was found here and in other studies that included some form of facial feature list, reinforcing the importance of using a systematic facial feature list.
Assuntos
Reconhecimento Facial , Ciências Forenses/métodos , Guias como Assunto/normas , Fotografação , Televisão , Gravação em Vídeo , Adulto , Bases de Dados Factuais , Humanos , Masculino , Valor Preditivo dos Testes , Sensibilidade e Especificidade , África do SulRESUMO
With increases in migration across borders, age estimation in living individuals of not (reliably) documented identity becomes all the more important. Unfortunately, there are not many age indicators that can be used for this purpose, and human variation requires specific methodical approaches. In this paper, a recently proposed age marker to assess the age around the critical age limit of 18 completed years is tested. The method uses apophyseal development of cervical vertebrae 2, 3 and 4. Here CT scans of a large sample of Turkish individuals (n = 1276) were assessed, and likelihoods of being 18 years at a given stage were calculated. The likelihood of being at least 18 years for stages 0, 1 and 2 were zero or close to zero in both males and females. By the time that stage 4 was reached, the likelihood to be 18 years were between 65 and 70% (depending on the vertebra) in females and 81 and 90% in males. In comparison to South Africans, the Turkish individuals developed earlier, but the likelihoods of being 18 years were lower at stage 4 as some individuals were still judged to be in stage 3 well into their twenties. Although fairly variable, this method is a valuable new addition to the modalities that can be used for age assessment in the living. CT scans seemed to provide good visualization of the structures in question, although in actual forensic cases the high radiation dose may be problematic.
Assuntos
Determinação da Idade pelo Esqueleto/métodos , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/crescimento & desenvolvimento , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Tomografia Computadorizada por Raios X , Turquia , Adulto JovemRESUMO
OBJECTIVES: The purpose of this study was to measure the mandibular angle as a reflection of the biomechanical forces acting on the mandible and relate it to aging and loss of teeth. METHODS: A total of 717 mandibles of adult individuals were selected from the Pretoria Bone Collection. These mandibles were allocated to dentition subgroups according to their pattern of tooth loss. The angle of the mandible was measured with a mandibulometer. The variation in the mandibular angle was statistically analyzed by age regressions and comparisons between adjusted means of dentition subgroups. RESULTS: Aging per se was not associated with a greater mandibular angle. With limited tooth loss, aging was associated with a smaller mandibular angle in females. Generally the mandibular angle increased with tooth loss and was accentuated when an even occlusion pattern was lost rather than with more extensive tooth loss. A more pronounced increase in mandibular angle with tooth loss was noted in females and individuals of European ancestry. CONCLUSIONS: Tooth loss and not aging is associated with an increase in the mandibular angle. Masculinity and being from African ancestry provided some protection against an increase in the mandibular angle with tooth loss. The accentuated increase in the mandibular angle when an even occlusion pattern was disturbed supports the notion that an uneven loss of teeth was indeed associated with inefficient mastication. The unexpected decrease in angle noted in females with aging but limited tooth loss may be indicative of constructive changes beyond puberty. Am. J. Hum. Biol. 28:681-686, 2016. © 2016 Wiley Periodicals, Inc.
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Envelhecimento , Dentição , Mandíbula/anatomia & histologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/etnologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , África do Sul , Adulto JovemRESUMO
Paleopathologists study the presence of diseases in the past and as such have a vast knowledge of skeletal changes associated with different conditions. Tuberculosis is one of the most studied diseases and still remains a major health problem today. Its manifestations in past populations have been extensively described, but less is known about its bony involvement in the post-antibiotic era. The aim of this study was to assess the frequency and manifestations of skeletal lesions in the post-antibiotic era in a South African sample and compare it to that found before the introduction of antibiotics. Skeletons of 205 individuals from modern skeletal collections and who are known to have died from TB were assessed. It was found that 39.2% of all individuals dying in the post-antibiotic era showed skeletal changes that could be associated with TB, while another 27.5% showed nonspecific changes. The highest incidences were found in individuals who died after 1985, when co-infection with HIV and drug resistance became common. While, as expected, vertebral and rib changes were the most common, the number of individuals who showed changes to the skull, and specifically intracranially, was surprising. These could most probably be associated with TB meningitis, although this specific cause of death was noted in only a few individuals. It seems that individuals may be living longer as a result of long-term antibiotic use, leaving more time for lesions to develop. Clin. Anat. 29:854-861, 2016. © 2016 Wiley Periodicals, Inc.
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Esqueleto/patologia , Tuberculose/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , PaleontologiaRESUMO
Diffuse idiopathic skeletal hyperostosis (DISH) is a disease primarily affecting the spine. However, it is also associated with the ossification/calcification of tendon, ligament, and capsule insertions (entheses) occurring at multiple peripheral sites. The etiology of the condition is unknown, as the name suggests (diffuse idiopathic skeletal hyperostosis), although some correlations with diabetes mellitus, obesity, and age have been noted. Clinical diagnostic criteria have been adapted for paleopathological assessment of archeological skeletal remains, revealing some interesting patterns between monastic and lay populations; showing a higher incidence of DISH among individuals buried in monastic cemeteries. Although fascinating, the mechanisms behind this difference in prevalence are still not fully understood and have been attributed to the relatively richer diets of the monks and priests. The development of diagnostic criteria, where early stage cases of DISH can be identified as well as a better understanding of its causes, is paramount to the prevention of this potentially debilitating condition and perhaps this is where paleopathologists can assist. The use of dry bone rather than living patients for detailed assessment means that paleopathologists are less restricted by the techniques they can use in their investigations and the condition's occurrence in various archeological assemblages can provide interesting insights into its etiology. Clin. Anat. 29:870-877, 2016. © 2016 Wiley Periodicals, Inc.
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Hiperostose Esquelética Difusa Idiopática/diagnóstico , Osso e Ossos/patologia , Diagnóstico Diferencial , Humanos , Hiperostose Esquelética Difusa Idiopática/patologia , PaleopatologiaRESUMO
The prevalence of cribra orbitalia (CO) is often used as an indicator of the general health status of past populations. Although debates as to its exact etiology are still ongoing, cribra is generally accepted to be the result of an anemic condition. Cribra has been reported to be declining in modern populations or even to be absent. The aim of this study was to compare modern, historic, and prehistoric prevalences of CO to assess whether it has changed through time and if it still occurs in contemporary populations. CO in skeletons (n = 844) from two widely different regions, the northeastern US and the central Gauteng area of South Africa, were compared in order to evaluate temporal trends. The sample comprised 245 prehistoric, 381 historic, and 218 modern skeletons. In adult skeletons the prevalence was found to be lower in historic South Africans (2.23%) than in historic North Americans (6.25%). It was lower in modern North Americans than in modern South Africans (12.35 and 16.8%, respectively). Its prevalence in prehistoric North Americans (11.86%) was also not much different from that of modern North Americans (12.35%). The frequency of CO in historic South African juveniles was higher (10.71%) than in historic North American juveniles (1.35%). Modern South African children had a lower frequency (25.14%) than modern American juveniles (40%), although the sample in the North American group was small. It seems that CO is still present in modern populations, and that health may indeed have declined for some groups in recent times. Clin. Anat. 29:823-830, 2016. © 2016 Wiley Periodicals, Inc.
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Doenças do Desenvolvimento Ósseo/epidemiologia , Órbita/patologia , Adulto , Desenvolvimento Ósseo , Doenças do Desenvolvimento Ósseo/patologia , Criança , Humanos , América do Norte/epidemiologia , Paleopatologia , Porosidade , África do Sul/epidemiologiaRESUMO
Histology is used to describe post-mortem bone alterations, trauma, pathology and age estimation and to separate human and non-human bones. Many scholars are however not familiar with the intricate and variable microstructure of bone, and due to the complex nature of some classification systems, bone histomorphology is often incorrectly described or identified. Little information is available on the histomorphology of non-human bones found in southern Africa, and therefore, the aim of this study was to describe the histomorphology of non-human species commonly found in southern Africa, namely, impala and monkeys, along with cat, dog, cow, sheep, equid and pig. Human femora were included for comparative purposes. The periosteal surface of femora was described and focussed only on the arrangements of vascular canals, primary osteons and secondary osteons. The results compared favourably to other studies and also added a histomorphological description of impala femora which consisted of primary vascular longitudinal bone tissue. A large degree of overlap and combinations of bone tissue types was observed, as well as evidence which allows animals from similar taxonomic orders to be grouped together. Primary vascular bone was primarily observed in artiodactyls (cow, pig, sheep and impala), while Haversian bone was recognised in carnivores (cat and dog), Perissodactyla (horses and donkeys) and primates. These differences can be used to exclude human from unknown bone fragments and also serve to caution investigators when using animal models to infer human bone tissue responses to thermal damage, ballistic trauma, etc., as bone tissue types different to that of human bone may respond differently.
Assuntos
Fêmur/anatomia & histologia , Antropologia Forense/métodos , Mudanças Depois da Morte , Animais , Diagnóstico Diferencial , Humanos , Periósteo/patologia , África do Sul , Especificidade da EspécieRESUMO
Diagnosis of specific infectious diseases in the skeleton is often difficult and relies on expert opinion. Statistics is not often used as a tool to assist in such diagnoses, and therefore this study aimed at employing data mining and machine learning in the form of decision tree analysis to aid in recognizing tuberculosis (TB) in skeletal remains and find patterns of skeletal involvement. The sample included 387 modern South African individuals (n = 207 individuals known to have died of TB and n = 180 as a control group) which were scored for the presence or absence of 21 skeletal lesions documented to be associated with TB. A pruned decision tree classification analysis was done to detect significant patterns and associations between variables which produced a model with a moderate classification rate based on four of the variables. As expected, vertebral changes were selected first, followed by rib, acetabular and lastly cranial changes. As a proof of concept, it was shown that machine learning was able to identify patterns of changes in TB skeletons versus a control group. However, further investigation into the use of machine learning in assessing skeletal changes associated with specific diseases is needed.
Assuntos
Tuberculose , Humanos , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Esqueleto/patologia , Árvores de DecisõesRESUMO
OBJECTIVE: This study assessed the sensitivity and specificity of skeletal lesions to accurately diagnose TB in a pre-antibiotic South African skeletal sample. MATERIALS: A total of 435 skeletons of individuals who died before 1950 from the Raymond A. Dart Collection of Human Skeletons. 176 died of TB, 109 died of other pulmonary diseases, and 150 died of other causes. METHODS: The presence / absence of 23 skeletal lesions were assessed for differences in frequency between groups. Sensitivities and specificities were calculated and compared to Dangvard Pedersen et al. (2019). RESULTS: Lesions on the ventral surface of thoracic and lumbar vertebral bodies were observed significantly more often in TB and pulmonary cases than in other cause of death group and yielded a 55% probability of a true TB diagnosis, if observed. An association between skeletal lesions and TB was found for rib and vertebral lesions. CONCLUSIONS: The results suggest that even when not documented to have died of TB, TB-related changes are observed in many individuals in a South African skeletal sample, indicating that they may have been infected with the disease. SIGNIFICANCE: The study provides information that can assist palaeopathologists in making inferences about the prevalence of TB in past populations. LIMITATIONS: Sample sizes were small, and the inclusion of a pulmonary disease group may have confounded the results. SUGGESTIONS FOR FURTHER RESEARCH: The selection of a control group without any possible contact with TB may improve the results and should be investigated.
Assuntos
Doenças Ósseas , Tuberculose , Humanos , África do Sul , Tuberculose/patologia , Esqueleto/patologia , Doenças Ósseas/patologia , AntibacterianosRESUMO
The accurate radiological detection of skeletal trauma is crucial for the investigation of blunt force trauma (BFT) cases. The sensitivities of CTs, X-rays and Lodox in identifying BFT fractures and minimum number of impacts in pigs, used as proxies for adult humans, were assessed. Ten human sized pig carcasses were struck with a mallet and scanned, after which the number of fractures and minimum number of impacts detected radiologically were recorded. Pig carcasses were then macerated, and the defleshed, skeletonized remains were considered the gold standard as far as number and location of fractures were concerned. CTs were most sensitive in identifying fractures and impacts in all body regions, with overall sensitivities of 55.4% and 71.5% respectively, while X-rays and Lodox had sensitivities of 25.8% and 29.3% for fractures, and 43.5% and 41.1% for impacts, respectively. All modalities were highly specific for identifying fractures (CT: 99.1%; X-ray: 98.9%; Lodox: 99.4%). CTs should be used to analyze blunt force trauma when a radiological assessment is required, but an examination of the defleshed bones remains the gold standard for the deceased whenever feasible. X-rays and Lodox have limited diagnostic value in these cases and relying on them to detect fractures may compromise the accurate forensic investigation of blunt trauma victims. However, the use of Lodox for initial screening of major trauma is still of value. Sensitivities are generally higher for detecting fractures in pigs compared to piglets, indicating that increased diagnostic value is achieved when imaging pigs compared to piglets.
Assuntos
Fraturas Ósseas , Ferimentos não Penetrantes , Animais , Fraturas Ósseas/diagnóstico por imagem , Humanos , Radiografia , Sensibilidade e Especificidade , Suínos , Imagem Corporal Total , Ferimentos não Penetrantes/diagnóstico por imagem , Raios XRESUMO
Radiological diagnostic errors are common and may have severe consequences. Understanding these errors and their possible causes is crucial for optimising patient care and improving radiological training. Recent postmortem studies using an animal model highlighted the difficulties associated with accurate fracture diagnosis using radiological imaging. The present study aimed to highlight the fact that certain fractures are easily missed on CT scans in a clinical setting and that caution is advised. A few such cases were discussed to raise the level of suspicion to prevent similar diagnostic errors in future cases. Records of adult patients from the radiological department at an academic hospital in South Africa were retrospectively reviewed. Case studies were selected by identifying records of patients between January and June 2021 where traumatic fractures were missed during initial imaging interpretation but later detected during secondary analysis or on follow-up scans. Seven cases were identified, and the possible causes of the diagnostic errors were evaluated by reviewing the history of each case, level of experience of each reporting radiologist, scan quality and time of day that initial imaging interpretation of each scan was performed. The causes were multifactorial, potentially including a lack of experience, fatigue, heavy workloads or inadequate training of the initial reporting radiologist. Identifying these causes, openly discussing them and providing additional training for radiologists may aid in reducing these errors. Contribution: This article aimed to use case examples of missed injuries on CT scanning of patients in a South African emergency trauma setting in order to highlight and provide insight into common errors in scan interpretation, their causes and possible means of mitigating them.
RESUMO
Linear measurements taken from bony landmarks are often utilised in facial approximation (FA) to estimate and plan the placement of overlying soft tissue features. This process similarly guides craniofacial superimposition (CFS) practices. Knowledge of how hard and soft tissue features spatially relate around the mouth region is, however, limited. Geometric morphometric techniques have thus been used to investigate size and shape variation in dentition-to-lip mouth morphology in a South African population. Twenty landmarks (twelve dentition, eight lips) were digitised, using cone-beam CT images of the anterior craniofacial complex in a Frankfurt/Frankfort position, for 147 individuals aged between 20 and 75 years. Principal Component Analysis and Canonical Variate Analysis established that much shape variation exists. A two-way ANOVA identified significant (p < 0.0001) population and sex variation with mouth shape. Black individuals presented with thicker lips, with the oral fissure aligning closely to the dental occlusion. Oral fissure position for white individuals corresponded to the inferior one-quarter (females) or one-sixth (males) of the maxillary central incisor crowns. Males presented larger dimensions than females, but females had a greater lip-to-teeth height ratio than their male counterparts. A pooled within-group regression analysis assessed the effect of age on the dentition and lips and found that it had a significant (p < 0.0001) impact on mouth shape. Ageing was associated with a reduced lip and teeth height, increased mouth width, and a lowered oral fissure and cheilion placement. The generated mean shape data, with metric guides, offer a visual and numerical guide that builds on existing FA and CFS standards, enhancing our understanding of hard and soft tissue relationships.
Assuntos
Lábio , Adulto , Idoso , Tomografia Computadorizada de Feixe Cônico , Dentição , Face/anatomia & histologia , Face/diagnóstico por imagem , Feminino , Humanos , Lábio/anatomia & histologia , Lábio/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Disguises are commonly used to mask a person's facial appearance in areas under closed-circuit television (CCTV) surveillance. While many studies attempted to understand the effects of disguises, such as hats and glasses, on facial recognition, limited studies have looked at disguises in forensic facial comparison. The aim of this study was to compare the outcomes of forensic facial comparison by morphological analysis (MA) in a CCTV sample with sunglasses and brimmed caps. The sample was obtained from the Wits Face Database and organized into 81 face pools of one target facial image wearing a disguise (cap or sunglasses) and 10 potential matching images. MA was conducted across face pools, and confusion matrices were used to assess the outcomes. Surprisingly, sunglasses had limited effect on MA performance both in accuracy (90.4%) and in reliability (κ = 0.798), while caps markedly decreased both accuracy (68.1%) and reliability (κ = 0.639). Error rates were associated primarily with false negatives in both samples (caps: 42.4%; sunglasses: 16.1%) despite the sample distribution favoring false-positive errors, which were very low (caps: 0.6%; sunglasses: 0%). Similarly to other studies, hats and caps were more harmful to correct identification when compared to sunglasses, which actually resulted in better accuracy than regular CCTV recordings. The effect of brimmed caps on accuracy was attributed to the overall loss of facial information caused. On training analysts, it may be helpful to instruct purposefully avoiding overreliance on easily disguised facial features, as other regions of the face also contain substantial feature information.
Assuntos
Vestuário , Óculos , Reconhecimento Facial , Ciências Forenses , Humanos , Fotografação , Gravação em VídeoRESUMO
Facial comparison is an important yet understudied discipline in forensics. The recommended method for facial comparison in a forensic setting involves morphological analysis (MA) with the use of a facial feature list. The performance of this approach has not been tested across various closed-circuit television (CCTV) conditions. This is of particular concern as video and image data available to law enforcement is often varied and of subpar conditions. The present study aimed at testing MA across two types of CCTV data, representing ideal and less than ideal settings, also assessing which particular shortcomings arose from less-than-ideal settings. The study was conducted on a subset of the Wits Face Database arranged in a total of 225 face pools. Each face pool consisted of a target image obtained from either a high-definition digital CCTV camera or a low-definition analogue CCTV camera in monochrome, contrasted to 10 possible matches. The face pools were analysed and scored using MA and confusion matrices were used to analyse the outcomes. A notably high chance corrected accuracy (CCA) (97.3%) and reliability (0.969) was identified across the digital CCTV sample, while in the analogue CCTV sample MA appeared to underperform both in accuracy (CCA: 33.1%) and reliability (0.529). The majority of the errors in scoring resulted in false negatives in the analogue sample (75.2%), while across both CCTV conditions false positives were low (digital: 0.3%; analogue: 1.2%). Even though hit rates appeared deceptively high in the analogue sample, the various measures of performance used and particularly the chance corrected accuracy highlighted its shortfalls. Overall, CCTV recording quality appears closely associated to MA performance, despite the favourable error rates when using the Facial Identification Scientific Working Group feature list.