Applications of forensic anthropology methodology: accuracy of virtual face reproductions performed on the Tenchini collection.

Facial reproduction validation uses the methodology typical of forensic anthropology to confirm the accuracy of three-dimensional reproductions of faces. Achieving high accuracy in virtual facial reproductions is still under study. In the present paper, the Tenchini collection, which contains wax reproductions of prisoners' faces and their skulls, was used. By creating facial reproductions on skulls from this collection, the result was compared with the real face of the person to whom the skull belongs. The three-dimensional volume of each examined skull of Tenchini collection was acquired via CT scan and photogrammetry. Subsequently, the virtual reproduction of each skull was processed using three-dimensional graphics software (ZBrush, Pixologic®). The morphological comparison parameters used in the field of personal identification by forensic anthropology were used. The blind procedure required the operator to see the mask subsequent to the facial reproduction phase, so that the facial reproduction cannot exploit the information that knowledge of the mask would have produced. The parameters used in the study of facial reproductions have shown discrepancies between the characteristics of the masks and the facial reproductions, partly expected because due to the lack of soft tissue on the skull. However, a high degree of accuracy in the facial reproductions performed due to the applied methodology was documented. The present study allowed us to observe how these parameters can be useful to study the accuracy of facial reproduction and identify what difficulties are encountered in producing a result close to the real appearance.

The rights of migrants to the identification of their dead: an attempt at an identification strategy from Italy.

Europe is turning a blind eye on a humanitarian disaster unfolding at its doorsteps, with thousands of migrants dying unidentified in Mediterranean waters. Since 2014, Italy has been struggling in an almost indifferent international scenario to identify its dead migrants. Despite the lack of sufficient resources, of the difficulties in collecting post mortem data from the disseminated bodies, and of the problems of contacting and collecting ante mortem information from relatives, it has been proven, with a series of pilot studies, that not only can these bodies be identified but that relatives are also looking for their loved ones and need death certificates. This article focuses on the administrative limbo and lack of regulations obliging single states to engage in appropriate procedures to maximise identification.

Forensic anthropology in the global investigation of humanitarian and human rights abuse: Perspective from the published record.

Forensic anthropologists have played key roles in the historical development of forensic science applications to global humanitarian and human rights issues. These anthropological initiatives can be traced back to the Smithsonian seminar organized by T. D. Stewart in 1968 and published in 1970. Key developments include the 1984 delegation sent by the American Association for the Advancement of Science to Argentina and the formation of the Argentine Forensic Anthropology Team. Subsequent highlights include major anthropological involvement in support of investigations by international criminal tribunals, formation of forensic anthropology teams in different countries and activities of the International Commission of Missing Persons and the forensic unit of the International Committee of the Red Cross. Recent developments feature the formation of the Humanitarian and Human Rights Resource Center of the American Academy of Forensic Sciences and its support of worthwhile projects in many countries. The published record provides historical perspective on these developments.

Setting the light conditions for measuring root transparency for age-at-death estimation methods.

Age-at-death estimation is one of the main goals in forensic identification, being an essential parameter to determine the biological profile, narrowing the possibility of identification in cases involving missing persons and unidentified bodies. The study of dental tissues has been long considered as a proper tool for age estimation with several age estimation methods based on them. Dental age estimation methods can be divided into three categories: tooth formation and development, post-formation changes, and histological changes. While tooth formation and growth changes are important for fetal and infant consideration, when the end of dental and skeletal growth is achieved, post-formation or biochemical changes can be applied. Lamendin et al. in J Forensic Sci 37:1373-1379, (1992) developed an adult age estimation method based on root transparency and periodontal recession. The regression formula demonstrated its accuracy of use for 40 to 70-year-old individuals. Later on, Prince and Ubelaker in J Forensic Sci 47(1):107-116, (2002) evaluated the effects of ancestry and sex and incorporated root height into the equation, developing four new regression formulas for males and females of African and European ancestry. Even though root transparency is a key element in the method, the conditions for measuring this element have not been established. The aim of the present study is to set the light conditions measured in lumens that offer greater accuracy when applying the Lamendin et al. method modified by Prince and Ubelaker. The results must be also taken into account in the application of other age estimation methodologies using root transparency to estimate age-at-death.

A history of forensic anthropology.

Forensic anthropology represents a dynamic and rapidly evolving complex discipline within anthropology and forensic science. Academic roots extend back to early European anatomists but development coalesced in the Americas through high-profile court testimony, assemblage of documented collections and focused research. Formation of the anthropology section of the American Academy of Forensic Sciences in 1972, the American Board of Forensic Anthropology in 1977/1978 and other organizational advances provided important stimuli for progress. While early pioneers concentrated on analysis of skeletonized human remains, applications today have expanded to include complex methods of search and recovery, the biomechanics of trauma interpretation, isotopic analysis related to diet and region of origin, age estimation of the living and issues related to humanitarian and human rights investigations.

Evaluation of macroscopic changes and the efficiency of DNA profiling from burnt teeth.

Identification of human remains subjected to incineration is extremely challenging. Our study evaluates the macroscopic changes and efficiency of DNA profiling in burnt teeth under controlled temperature and time conditions. 28 teeth were exposed to temperatures between 100 and 700°C for a duration of 1-15min. Two non-burnt teeth were used as control. Macroscopic changes were evaluated and recorded. DNA was extracted using a silica-based methodology. Efficiency of DNA profiling was assessed through Quantitative PCR for STRs. Burnt teeth reached chalky white appearance at 400°C 5min and fractures were observed from 300°C 10min. Amplification of STRs was very low from 300°C and 1 or 5min. In contrast, the housekeeping gene, GAPDH, was amplified in all combinations of temperatures and times. Although it is possible to amplify the housekeeping gene at high temperature, DNA profiling is difficult to obtain, probably due to small size of these regions making them more prone to degradation.

Facial growth parameters in Down syndrome: Review of the literature and forensic application for missing persons age progression.

PURPOSE: Individuals with Down syndrome (DS) show growth trajectories which deviate from standard ones due to variations in the growth of facial structures. Studying the effect of aging on the faces of DS individuals is necessary to obtain an accurate result through age progression, a technique based on the study of physiognomic features and used in cases of missing persons. Here we present scientific publications that delve into the rhythms of aging and morphological characteristics of facial features in DS individuals to enable appropriate age progression in cases of missing DS individuals. RESULTS: The scientific literature considered in this review studies the growth of soft tissue and bone substrate by comparing standard growth values with those measured through anthropometric measurements of individuals with DS. Growth trajectories are described by considering morphological trends both by comparing standard values with those found in individuals with DS and by observing individual physiognomic traits. CONCLUSIONS: When a young individual with DS goes missing, the realization of an age progression requires knowledge of the aging dynamics peculiar to the DS face. Therefore, physical, cognitive, and clinical factors must be considered. Delayed physical development and early aging, such as the onset of puberty and weight gain, have an important impact on the realization of age progression. In fact, depending on the life period to be considered, the effects of aging must be calibrated based on the knowledge gathered from scientific research.

Father figure: Study of the age progression process from old pictures and its value in forensic sciences.

The application of age progression to the search for missing persons demonstrates its usefulness in being able to reconstruct the aged face based on the current age of a person who has been missing for many years. Age progression takes into account facial physiognomic elements and their changes over time. Based on these premises, the present study aims to investigate the evolution of somatic features, from childhood to adulthood, of one of the authors' father using photos at different ages of him. Sixteen photos were collected depicting an individual of Italian origin between the age of 1 and 72. The photos were processed in Adobe© Photoshop software to graphically highlight the shape development of individual physiognomic elements. The shape of the face, eyebrows, eyes, nose, mouth, and cheeks were analysed in detail using a morphological approach. The ageing processes that occurred in this case were discussed on the basis of the literature. The present study demonstrates the in-depth analysis of the dynamics of facial growth in a single case. Nonetheless, aging is different for each individual, so further studies are necessary to observe facial development on as many subjects as possible.

The forensic imaging technique of age progression used within missing people cases: The Italian Missing Children association realizing age progression for Missing Child Kenya.

The age progression technique allows to update identification photos of individuals who have been missing for years. This method is based on the study of the facial variation and on the dynamics of facial growth. Knowledge about changes in the distribution of facial fat and the tone of the cartilage allows realistic predictions of the facial appearance after many years. Beside these elements, age progression is also supported by similar characters between family members. This is why photos of the missing and family members are used to create an age progression, making the new identikit accurate. Non-profit associations are crucial for the dissemination of information on the problem of missing persons. In Italy, the Italian Missing Children association provides for free an age progression service with the support of forensic anthropology. With the activation of a protocol, consisting of guidelines, and a form for the request for age progression by family members, the Italian Missing Children has started a collaboration with Missing Child Kenya. It allowed to disseminate up-to-date photos of the presumed current appearance of the missing children in Kenya. Thus, in the present study some cases are reported, in which age progression technique was applied. The photos provided by Italian Missing Children were shown in video documentaries made by Missing Child Kenya, allowing to continue the dissemination of age progression photo during the Covid quarantines and to keep the population active in the search for the missing.

Forensic International Dental Database (FIDBv2) for adult age-at-death estimation in multiple forensic contexts: Strengthening the operationalization of the Lamendin criteria in a global scope model.

The aim of this study is to validate the FIDBv2 online procedure for adult age-at-death estimation using root dentine translucency (RDT) and periodontal retraction (PR) of single-rooted teeth in a worldwide sample. The sample includes 4810 teeth of 2559 individuals from 16 countries of America, Europe and Asia. Bias and inaccuracy between documented (DA) and estimated ages (EA) were calculated. Pearson and Intraclass Correlation Coefficients were computed to assess the strength of agreement between pairs of data, while Kolmogorov-Smirnov Z was used to evaluate the statistical significance of the differences. The percentages of correctly estimated cases within different age ranges were obtained to find trends in the reliability of the results. Most of the biases (-4.61-1.31 years) and inaccuracies (4.81-9.72 years) are low. The dispersion of EA increases with age and almost all the DA-EA correlations are above 0.75. DA-RDT and DA-PR correlations are positive, most of the former being high (0.74-0.91), and the latter being low (0.11-0.54). The highest percentages of correct estimations are identified for the ±7.5 and ±10 years ranges, and most comparisons of bias and inaccuracy between countries are non-significant. The high correlations between DA and EA suggest that the method is robust and reliable for a global application. Mean errors are low, with the best results found in the 30-69-year-old cohort. This research supports that the method is effective and accurate for age estimation in forensic contexts worldwide, thus reaffirming it is a generalizable procedure locally and internationally.

Stable Isotope Provenance of Unidentified Deceased Migrants-A Pilot Study.

In the global migration crisis, one of the challenges in the effort to identify deceased migrants is establishing their region of origin, which facilitates the search for ante mortem data to be compared with the post mortem information. This pilot study explores the potential of using stable isotope analysis to distinguish between individuals coming from West Africa and the Horn of Africa. Six individuals (four of known origin and two of unknown origin) were sampled. δ13CVPDB(keratin), δ15NVPDB(keratin) and δ18OVSMOW(keratin) of hair were analysed using Elemental Analyzers coupled with Isotope Ratio Mass Spectrometry (IRMS). δ18OVSMOW(carbonate) and δ13CVPDB(carbonate) of bone were analysed using GasBench II with IRMS, while 87Sr/86Sr composition was determined in bone and dental enamel using laser ablation multi-collector inductively coupled plasma mass spectrometry. The stable isotope compositions of the individual from the Horn of Africa differed from the other individuals. The differences found between 87Sr/86Sr of enamel and bone and between δ18O and δ13C in bone and hair reflect changes in sources of food and water in accordance with regionally typical migration journeys. The analysis of multiple stable isotopes delivered promising results, allowing us to narrow down the region of origin of deceased migrants and corroborate the information about the migration journey.

Age estimation through histological study of trabecular volume and cortical bone width of the iliac crest.

There have been many methods proposed to estimate the age of human bones in forensic medicine or in forensic anthropology, including those that assess histological structures. In this study, age was evaluated through the histomorphometric study of trabecular volume and cortical width of the right iliac crest. A total of 25 samples A total of 66 samples (42 male and 24 female) were obtained from necropsies of judicial cases, with ages ranging from 13 to 58years, who had died a sudden or violent death. The samples were obtained using Bordier's trocar for bone biopsy, in a period not exceeding 24h after death. The samples were examined without decalcification, with 96° alcohol dehydration, embedding in methyl methacrylate, and sectioned with a microtome Reichert (3µm). The sections were fixed on microscope slides and stained using toluidine blue, Goldner trichrome and hematoxylin-eosin methods. The samples were studied under a Leica DM LB microscope and the images were digitally captured. The digital images were processed using an image analysis program and data were analyzed using the SPSS statistical package. The results demonstrated that the combination of the trabecular volume and cortical width acted as predictors of the age in subjects which did not suffer from any deterioration of bone and/or mineral metabolism.

Application of Aspartic Acid Racemization for Age Estimation in a Spanish Sample.

Correct age-at-death estimation in adult individuals is one of the challenges of forensic investigation. Forensic anthropology macroscopic techniques are non-invasive methods for this purpose. However, several methods need to be applied to accurately estimate age, and the difference between chronological and predictive age may still be around ±10 years. New research trends are focused on the inherent process of aging, which produces changes in tissues and organs at different biochemical levels. One of the oldest and most studied approaches in this field is aspartic acid racemization. The accuracy of this technique in age estimation has been widely demonstrated. However, only a few studies have assessed its accuracy in different populations. The aim of this research was to assess the accuracy of aspartic acid racemization in a Spanish sample and its applicability to forensic cases. Dentin from fifteen third molars from two Spanish populations (ages 19-70 years old) was isolated and D and L forms of aspartic acid were detected through GC/MS, according to a previous published protocol. D/L ratios were calculated and after the application of a regression analysis, a formula for age estimation was developed. The results were similar to previous studies, obtaining an R = 0.91 between racemization ratios and age and a mean absolute error (MAE) between chronological and predictive age of 5 years. These results were ratified by leave-one-out cross-validation, as well as the application of the formula to five teeth of a known age. Despite these promising results, this technique is not exempt from drawbacks; thus, further studies are required to apply this methodology to forensic cases and to combine it with forensic anthropology findings.

Age estimation of individuals aged 5-23 years based on dental development of the Indonesian population.

Dental development can be used to estimate age for forensic purposes. However, most of the currently available methods are less reliable for the Indonesian population due to population variability. This study presents a new method and evaluates other methods that utilize dental development to estimate the age of Indonesian people. Panoramic radiographs of 304 young Indonesian people aged 5-23 years old were analysed for deciduous tooth root resorption, permanent tooth calcification, and eruption. The extent of tooth root resorption was determined based on AlQahtani's modified Moorrees et al. method. Tooth calcification was classified based on a modified Demirjian et al. method. Tooth eruption was evaluated based on AlQahtani's modified Bengston system. The sequence of tooth root resorption, and permanent tooth calcification and eruption were grouped into 19 age categories (from 5-23 years old) in an atlas. The differences between males and females, between maxillary and mandibular teeth, and between right and left teeth were also analysed. There were minimal significant differences of tooth development between males and females, and between the right and left teeth (P > 0.05), while the maxillary and mandibular dental development was significantly different (P < 0.05). The newly developed atlas showed the development of the right side of maxillary and mandibular tooth of combined sex of Indonesian population. Another 34 panoramic radiographs of known-age and sex individuals from Indonesia were assessed using the newly developed Atlas of Dental Development in the Indonesian Population, Ubelaker's Dental Development Chart, The London Atlas of Human Tooth Development and Eruption by AlQahtani, and the Age Estimation Guide-Modern Australia population by Blenkin-Taylor. Accuracy was assessed by comparing estimated age to actual chronological age using the Bland-Altmand test. Results show that the smallest range of error was found in the Atlas of Dental Development in the Indonesian Population (-0.969 to 1.210 years), followed by The London Atlas of Human Tooth Development and Eruption by AlQahtani (-2.013 to 1.990 years), the Age Estimation Guide-Modern Australia population by Blenkin-Taylor (-2.495 to 2.598 years), and the Dental Development Chart by Ubelaker (-2.960 to 3.289 years). These findings show that the Atlas of Dental Development constructed in this study performs better than the other three methods and presents greater accuracy of age estimation in the Indonesian population.Key pointsDental development such as deciduous tooth root resorption, permanent tooth calcification, and tooth eruption can be used to estimate age for forensic purposes.The development of the teeth are influenced by genetic, ethnicity, and sex, therefore an age estimation method must be constructed based on the same population.There were minimal significant differences in tooth development between male and female, and between right and left teeth, but there was significant difference between maxillary and mandibular teeth.The Atlas of Dental Development in the Indonesian Population constructed in this study allowed more accurate age estimation of the Indonesian sample than the other methods tested. Supplemental data for this article are available online at https://doi.org/10.1080/20961790.2021.1886648.

Identification of a decedent in a 103-year-old homicide case using forensic anthropology and genetic genealogy.

Anthropologists are often the custodians of long-term unidentified human remains though their positions as curators of university or museum skeletal collections. Various factors decrease the solvability of these legacy cases including the passage of time, the loss of provenience for specific cases, and lack of documentation or case records. While anthropologists can contribute important information toward identification, it is often necessary to explore novel and cross-disciplinary strategies to resolve difficult cold cases. In long cold cases, the postmortem interval, in particular, may be difficult to estimate leading to further challenges in achieving identification. Modern advances in radiocarbon bomb pulse dating, isotope analysis, and actualistic studies have contributed to positive identification of unidentified human remains in some legacy cases, but may not be available to all forensic practitioners and law enforcement from resource-poor agencies. Pooling resources, as well as collaborating with professionals outside of forensic anthropology, is a useful strategy to pursue when anthropological methods are exhausted.The case study presented here demonstrates a collaborative approach between forensic anthropologists, forensic genetic genealogists, and law enforcement in a century-old homicide. The dismembered and mummified parts of a male body were recovered in a remote cave in 1979 and again in 1991. Despite forensic anthropologists creating and updating the biological profile over the decades from recovery to present, no identification was made until the application of forensic genetic genealogy (FGG) to the case in 2019. New interpretations of bone microstructure and trauma analysis are presented for the case, alongside the historical documentation and "proof of life" evidence used by the genealogy team. A review of the FGG methods underscores the challenges in this case (e.g. significant endogamy, multiple aliases used by the victim) and the steps taken toward resolution. Ultimately, a combined anthropology and genealogy approach resulted in a confirmed identity for a man who was murdered in 1916.Key pointsForensic scientists should leverage a collaborative, interdisciplinary approach toward human identification.When combined with forensic anthropology methods, forensic genetic genealogy is a valuable tool linking biological and cultural-historical aspects of identity.Forensic anthropologists should review challenging cases in their labs as new methods are introduced and new resources become available.

Purkait's triangle revisited: role in sex and ancestry estimation.

Identification of unknown remains recovered from marine and terrestrial locations is a significant humanitarian problem. This investigation proposes a simple method applicable to fragmentary femora for a more refined level of ancestry and/or sex estimation. To that end, we re-examined Purkait's triangle which involves three inter-landmark distances between the traction epiphyses and the articular rim of femoral head. A large sample (n = 584) from geographically diverse (Egyptian, Indian and Greek) populations was compiled. Additionally, shape (n = 3) and trigonometrically derived variables and ratios (n = 9 variables) were employed to detect any geographically-clustered morphological differences between these populations. Random forest modelling (RFM) and linear discriminant function analysis (LDA) were employed to create classification models in instances where sex was known or unknown. The sample was apportioned into training and test sets with a ratio 70/30. The classification accuracies were evaluated by means of k fold cross-validation procedure. In sex estimation, RFM showed similar performance to LDA. However, RFM outperformed LDA in ancestry estimation. Ancestry estimation was satisfactory in the Indian and Egyptian samples albeit the Greek sample was problematic. The Greek samples presented greater morphological overlap with the Indian sample due to high within-group variation. Test samples were accurately assigned to their ancestral category when sex was known. Generally, higher classification accuracies in the validation sample were obtained in the sex-specific model of females than in males. Using RFM and the linear variables, the overall accuracy reached 83% which is distributed as 95%, 71% and 86% for the Egyptian, Indian and Greek females, respectively; whereas in males, the overall accuracy is 72% and is distributed as 58%, 87% and 50% for the Egyptian, Indian and Greek males, respectively. Classification accuracies were also calculated per group in the test data using the 12 derived variables. For the females, the accuracies using the medians model was comparable to the linear model whereas in males the angles model outperformed the linear model for each group but with similar overall accuracy. The classification rates of male specific ancestry were 82%, 78% and 56% for the Egyptian, Indian and Greek males, respectively. In conclusion, Purkait's triangle has potential utility in ancestry and sex estimation albeit it is not possible to separate all groups successfully with the same efficiency. Intrapopulation variation may impact the accuracy of assigned group membership in forensic contexts. Key pointsPurkait's method is a possible ancestry group indicator applicable to fragmentary femora.Random forest model surpassed linear discriminant function analysis in multi-group ancestry classification.Ancestry is more accurately assessed in females than males.The intertrochanteric distance is the most important feature in discrimination of sex whereas in ancestry it was the head to lesser trochanter distance.Sex differences override ancestry due to the tendency of misclassification into same sex but different group rather than the opposite sex of the same ancestry.

Lag time of modern bomb-pulse radiocarbon in human bone tissues: New data from Brazil.

Radiocarbon analysis with reference to the modern bomb-curve was conducted using 68 bone samples of a vertebral body, femoral diaphysis, occipital bone, and parietal bone of 17 adults from Brazil. All individuals were born in 1963, thus analysis focused on the correlation with atmospheric values during the more recent, falling portion of the curve. Ages at death ranged from 43 to 54 years with representation of both sexes. Lag time (difference between the actual death date and the year of correspondence of the radiocarbon value with the curve) was evaluated for each individual and each tissue. The mean of the lag time values was 20.2 years, and the median was 22.0 years. The femur had the highest lag time median (29.5 years) among the bone groups, followed by the occipital (25.5 years), parietal (23.5 years) and the vertebra (8.0 years). The same pattern was observed for both sexes, but females tended to have lower lag time values than males. Different tissues presented considerable variation in lag time with vertebral bodies the least and the femoral diaphysis the greatest. These data suggest that individual age at death and the associated lag time must be considered in estimating the approximate death date. The lag time values for vertebral bodies were lower and with less variability in comparison with values for the occipital, parietal, and femur indicating greater consistency of that bone group for time since death estimation in the studied sample.

Fragment analysis in forensic anthropology.

Anthropological analysis of fragmentary evidence can be challenging but diverse methods allow substantial information to be gleaned. Scanning electron microscopy/energy dispersive X-ray spectroscopy enables determination if bone and/or tooth tissue is present. Protein radioimmunoassay or DNA analysis can establish the species present. Histological analysis can assist in species determination and reveal information about thermal changes. Radiocarbon analysis with special reference to the modern bomb-curve can clarify the postmortem interval. Anthropologists should also be aware that DNA analysis not only can enable positive identification but assist in the evaluation of sex and age at death.

Evaluation of ancestry from human skeletal remains: a concise review.

Ancestry assessment represents a major component of forensic anthropological analysis of recovered human remains. Interpretations of ancestry, together with other aspects of the biological profile, can help narrow the search of missing persons and contribute to eventual positive identification. Such information can prove useful to authorities involved in the identification and investigative process since many lists of missing persons have a reference to this parameter. Recent research has strengthened available methodologies involving metric, non-metric morphological as well as chemical and genetic approaches. This review addresses the new anthropological techniques that are now available, as well as the complex historical context related to ancestry evaluation.

The impact of scavenging: perspective from casework in forensic anthropology.

Forensic anthropology casework frequently encounters evidence of animal scavenging associated with fragmentation and loss of skeletal material. Published research demonstrates that patterns of destruction in bone can suggest the size and type of animal involved. This study analyzes 107 cases reported on by the first author at the Smithsonian Institution to investigate patterns of scavenging in forensic anthropology casework. This investigation reveals that the extent of scavenger impact varies across the body, but primarily is concentrated in the central body area. Although extensive animal scavenging can limit analysis, some evidence of foul play can be preserved.