Accuracy of estimating postmortem interval using the relationship between total body score and accumulated degree-days: a systematic review and meta-analysis.

OBJECTIVE: This study aims to evaluate the relationship between Total Body Score (TBS) and Accumulated Degree-Days (ADD) for estimating postmortem interval (PMI) using the decomposition quantification system by Megyesi et al. (Megyesi MS, Nawrocki SP, Haskell NH (2005) Using Accumulated Degree-Days to Estimate the Postmortem Interval from Decomposed Human Remains. J Forensic Sci 50:1-9. https://doi.org/10.1520/jfs2004017 ). DESIGN: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The methodological quality and risk of bias were assessed using the QUADAS-2 scoring system. Statical tests, including I2 for heterogeneity assessment and subgroup analysis comparing human and pig proxies across different decomposition stages, were performed for meta-analysis. RESULTS: The search identified 25 studies that underwent qualitative evaluation, all of which were included for quantitative analysis. The findings indicate that the TBS formula tends to overestimate ADD with a moderate mean difference of 0.5758 overall. Specifically, in pigs, ADD is overestimated significantly (1.1128), while there is a slight underestimation in humans (-0.0038). Across decomposition stages, fresh body (0.0066) and early decomposition (0.0338) show an insignificant overestimation, whereas advanced decomposition reveals a slight underestimation (-0.3378) and skeletonization indicates a substantial overestimation (1.6583). CONCLUSIONS: The relationship between TBS and ADD demonstrates high accuracy in humans during early decomposition stages, without differences in statistical significance. However, its accuracy diminishes as decomposition progresses, potentially leading to an overestimation of PMI.

Digital matching of palatal rugae patterns for forensic identification in edentulous denture wearers.

Identifying edentulous victims in forensic contexts poses a significant challenge. It has been reported that having a denture to reproduce and compare Palatal Rugae (PR) patterns is crucial for identifying edentulous individuals, yet there are no validated protocols for conducting this procedure. In this study, a new method was developed and validated for plaster molding of the internal surface of upper dentures, along with a protocol involving focus-stacked photographs and reference scales. Thirty-eight edentulous subjects participated in the study, obtaining plaster models of the patients (PM), and their dentures (AM) were standardized. The AM/PM model was highlighted and photographed with ten shots in different z-focuses for each model, using standard lighting and aligning the position of the PR perpendicular to the photographic axis using tubular spirit levels and modeling clay. The images were processed using the stacking technique and analyzed by three observers through the proposed protocol using Adobe® Photoshop®. The results were analyzed based on the intra-observer and inter-observer agreement levels, with a 95% confidence interval. This study demonstrated high-precision intra-observer and inter-observer agreement (k = 1) in the matching of Palatal Rugae (PR) and maxillary morphology obtained from participants and their dentures. The protocol is simple, cost-effective, and precise. It enables standardization of the technique for obtaining plaster models, and the exposure of PR and photographic protocol minimizes the presence of artifacts in the images, thereby reducing the likelihood of errors and promoting the reproducibility of both the recording technique and the comparison of the PR.

Undergraduate dental students and their potential role in disaster victim identification procedures: A scoping review under a Chilean perspective.

BACKGROUND: A mass fatality incident is an unexpected event that can cause the death of many people, which has motivated careful analysis and development of appropriate strategies for planning and response with all available resources. As these events involve multiple victims, their identities must be confirmed using the highest possible quality standards. Forensic Odontology (FO) has proven to be a scientific resource for disaster victim identification (DVI) procedures; however, it is highly dependent on the proper management not only of material resources but also of human resources. Chile is a country recognised as prone to natural disasters, but an insufficient number of forensic odontologists has been reported. The aim of the study was to review the literature on a dental undergraduate (UG) student's potential value in a DVI process. METHODOLOGY: A scoping review was performed using a specific search strategy in PubMed/Medline, Web of Science, Scopus, SciELO and EBSCO databases. RESULTS: The search identified 27 articles in which the basic dental degree, the necessary training and the need for human resources are variables considered in different priorities by those articles. DISCUSSION: It is vital to assess the local needs of Chile based on its UGs, considering that FO is an underestimated resource that should be included early on in dental curriculums. Furthermore, it should align with public policies to ensure viability and inclusion in standardised protocols. CONCLUSION: Although there is "potential" usage of UG dental students in DVI is not ideal, circumstances will dictate their use. The better trained they are as students, the more valuable their "potential" contribution will be.

Age estimation by evaluation of obliteration of the palatine sutures: a scoping review.

The age estimation (AE) of human remains is a challenging task since it is dependent on the state in which these remains are found. Since the macroscopic evaluation of palatal sutures has been proposed as a method for AE, the aim of this study was to review the literature on this method, considering that the cases of edentulous elderly are among the greatest challenges in anthropological and forensic contexts. A scoping review was performed using a specific search strategy in PubMed, Web of Science, SciELO, LILACS, and Google Scholar. The search identified 13 articles, among which the USA yielded the most information with 3 articles. Only 1 study was identified in Latin America (Peru). There was great diversity regarding the origin of samples, and the studies were carried out on both historical and modern populations. Only 6 articles exceeded the average sample size (168.08) and 4 articles studied samples of fewer than 100 individuals. Although 6 different methods were identified, Mann et al.'s revised method was the most used. The selection of appropriate methods for AE depends on what skeletal elements are present and the general age of the specimens. Although evaluation of the obliteration of the palatal sutures has been found to be simple and promising for AE in individuals over 60 years of age, this method has been reported to have less precision than other more complex methods, which makes the use of a combination of methods necessary to increase the level of confidence and the percentage of success. Further research could resolve this weakness, and methodological refinement (perhaps the digitization and automation of processes, or the application of Bayesian methodology) could provide the necessary solidity to comply with international standards in the forensic scenario.

Forensic odontology and dental age estimation research: a scoping review a decade after the NAS report on strengthening forensic science.

Dental age estimation (DAE) is one of the most reliable and useful scientific methods employed by forensic odontology (FO) for human identification. In 2009, the US National Academy of Sciences (NAS) report highlighted the need to deepen research in many disciplines, among which FO received strong criticism for specific expertise. The aim of this review is to provide a comprehensive overview in order to systematically map the latest original research done in FO, as well as identify DAE within this field. A systematic search was performed from 2014 to 2019. In total, 644 studies were identified for qualitative analysis: DAE was the most studied topic (41.30%). Asia was the most productive continent with 58.27% of the global production on DAE; India was the most productive Asian country, with 32.33% and 55.48% of global and Asian production, respectively. The University of Macerata (Italy), KU Leuven (Belgium), University of Split (Croatia), and University of São Paulo (Brazil) led DAE research. Authors from leading countries on DAE research demonstrated great individual productivity, which is evidence of their scientific efforts, but also possible risks if the continuity of this line of research depends on them. Although FO has significantly focused its research on DAE, the absence of publications on controversial topics but necessary for research according to the NAS report shows the possible lack of interest of authors or journals to address them.

Correction to: Sex estimation of infants through geometric morphometric analysis of the ilium.

After publication of the original article, it was brought to authors' attention two errors that were included in the final publication.

Sex estimation of infants through geometric morphometric analysis of the ilium.

In archeology or forensics, the analysis of the ilia is often used to determine the age and sex of unknown individuals. However, sex determination using the skeletal remains of individuals who did not develop secondary sexual characteristics remains controversial. Accurately estimating the sex of subadults is hampered by a small number of studies based on identified skeletal collections of juvenile individuals. Here, we analyzed the sexual dimorphism of the subadult ilia using geometric morphometric techniques and individuals from the osteological collection of identified subadults from San José's graveyard (Granada). Seventy-one left ilia from 40 males and 31 females aged between birth and 1 year were included in the analysis. Three landmarks and 27 semi-landmarks of the ilia were placed. By principal component analysis, we found that the size and shape of the ilia could be used to differentiate males and females.

Alterations of skull bones found in anencephalic skeletons from an identified osteological collection. Two case reports.

One of the most common conditions during fetal development is anencephaly, which often involves many identification difficulties in the context of physical anthropology, as it causes severe skull challenges. In this paper, we describe the alterations found in the skulls of two perinatal individuals with anencephaly from the osteological collection of identified infants in the Anthropology Laboratory of the University of Granada, Spain. Both subjects of study are in perfect state of preservation. Despite the severe malformations, all skull bones have been targeted and identified, as the possibility of studying a subject with a complete, articulated, and partially mummified skull; the other was disjointed and well preserved. The skull bones of these two individuals affected with anencephaly have been described in detail, allowing this pathological condition to be identified in skeletonized individuals in archaeological or forensic contexts, in cases where these bones did not have anatomical connection or when these were taphonomically altered.

Reliability of predictive models based on the mesiodistal and buccolingual diameters of permanent canine teeth for sex estimation in forensic contexts: A systematic review and meta-analysis.

This study aimed to assess the reliability of predictive models for sex estimation based on permanent canine size. A systematic literature review was performed by following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Six electronic databases were searched as the primary source of information. As a secondary source of information, a manual search was performed to identify additional relevant studies not captured in the initial search. After assessing the methodological quality and risk of bias with the Joanna Briggs Institute Critical Appraisal Tools for Systematic Reviews, the data were subjected to statistical tests for a meta-analysis of diagnostic test accuracy and Higgin's I2 statistic to evaluate the heterogeneity between the eligible studies. The systematic search resulted in 21 studies for qualitative synthesis, and 13 of them were selected for quantitative analysis. The analysis of 25 univariate predictive models showed an estimated sensitivity of 77.2 % and specificity of 67.1 %. Meta-regression analyses were performed for dental arch, the type of diameter and dental region outcomes for these univariate predictive models. Dental arch (p = 0.029) and the dental region of measurement (p = 0.001) were significant modifiers. The analysis of 25 multivariate predictive models showed an estimated sensitivity of 82.6 % and specificity of 70.1 %. There were significant methodological limitations and substantial heterogeneity among the included studies. Based on the results, there is insufficient high-quality scientific evidence to support the safe use of predictive models based on permanent canine measurements as the exclusive method for sex estimation in forensic settings.

Sex estimation based on deciduous and permanent dentition in a contemporary Spanish population.

Sex estimation of skeletal remains with satisfactory allocation accuracy represents an essential step in reconstructing the biological profile of unknown individuals in archaeological research and forensic practice. Teeth are among the most frequently recovered physical elements of an individual that remain after death due to their hardness, durability, and resistance to postmortem insults. This study was based on the deciduous and permanent dentition of 269 individuals (150 males and 119 females) from the Granada osteological collection of identified infants, young children, and adults (Granada, Spain). Mesiodistal, buccolingual, and diagonal crown and cervical diameters of both dentitions were measured, and logistic regression analyses were performed to create equations for sex discrimination. The results show that the first and second deciduous molars and the permanent canines are the teeth with the greatest sexual dimorphism, providing percentages of correct assignment of sex between 78.1 and 93.1% in deciduous dentition and between 79.4 and 92.6% in permanent teeth, depending on the dimensions used. The results indicate that this method may be applicable as an adjunct with other accepted procedures for sex estimation when fragmentary skeletal remains are encountered in archaeological excavations and in forensic contexts.

Use of dimensions in posterior dentition for sex estimation in forensic contexts: A systematic review and meta-analysis.

OBJECTIVE: This study assessed the validity of dimensions in posterior dentition for sex estimation in forensic contexts. DESIGN: A systematic review was established following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). After assessing the risk of bias and methodological quality with the QUADAS-2 system, the data were subjected to statistical tests for a meta-analysis of diagnostic accuracy and I2 to verify the heterogeneity. RESULTS: The search resulted in 15 studies that underwent qualitative testing, all were selected for quantitative analysis. The papers included: the mesiodistal of the upper first molar, lower first molar, and upper second molar, and the buccolingual of the upper first molar and upper second molar. The results showed that sensitivity and specificity rates were lower with the mesiodistal diameter, with rates of 0.577 for the lower first molar, 0.674 for the upper first molar, and 0.698 for the upper second molar, while the rates were higher with the buccolingual diameter, with 0.724 for the upper first molar, and 0.743 for the upper second molar. The power to estimate sex is greater for males than for females. High heterogeneity was detected among the studies of almost all dimensions, except sensibility for the lower first molar and specificity for the upper second molar. CONCLUSIONS: None of the dimensions reached an accuracy of ≥80%, however, so they are not a reliable method for sex estimation in forensic practice.

Radix entomolaris: A morphological variable of human dentition with anthropological relevance. A study on a Chilean population.

The existence of a third root in the mandibular first molars may have implications for certain dental treatments; however, its greatest relevance could be in anthropological and forensic sciences, because its prevalence varies significantly according to ethnic groups. The purpose of this research was to determine the prevalence of radix entomolaris (RE) in a sample of Chilean people. A random sample of 1330 digital periapical radiographs of endodontically treated mandibular first molars (551 males and 779 females, aged between 18 and 87 years) were evaluated. The prevalence of RE, its distribution by sex and root canal lengths were determined. Evidence demonstrated that the formation of RE is associated with ancestry and its frequency is variable according to populations studied, being more frequent in Asians and Native Americans. The prevalence of RE in the studied people was 3.16%, similar to frequencies reported in European individuals (3.4%-4.2%). The 61.90% of RE were located at the right side of the mandible and 38.10% at the left side. The average working length of RE was 19.52 mm. No statistically significant differences in frequencies were observed by sex (p = 0.19). The prevalence of RE varies among continental population groups. However, due to human migration, the frequency of this physical trait could be modified in specific geographic regions. The observed prevalence of RE in the study group was similar to the prevalence ranges observed for European ancestry populations and it was considerably lower than the data reported for non-Europeans. The absence of sexual dimorphism is consistent with results of previous studies performed worldwide.

Brief communication: the Granada osteological collection of identified infants and young children.

The objective of this study is to present the characteristics of a collection of identified infants and young children housed in the Laboratory of Anthropology of the University of Granada, Spain. The sample, which is still being enlarged, is currently composed of 230 complete skeletons aged from 5 months of gestation to 8 years, with a majority below 1 year. It mainly dates from the mid-20th century. The state of preservation is very good, and antemortem information is available from burial and death certificates, among other documents. Our sample makes an important contribution to the relatively few collections available in the world for investigating the osteological development of the skeletons of infants and young children from a physical anthropological perspective.

Post-Mortem Dental Profile as a Powerful Tool in Animal Forensic Investigations-A Review.

Veterinary forensics is becoming more important in our society as a result of the growing demand for investigations related to crimes against animals or investigations of criminal deaths caused by animals. A veterinarian may participate as an expert witness or may be required to give forensic assistance, by providing knowledge of the specialty to establish a complete picture of the involvement of an animal and allowing the Courts to reach a verdict. By applying diverse dental profiling techniques, not only can species, sex, age-at-death, and body size of an animal be estimated, but also data about their geographical origin (provenance) and the post-mortem interval. This review concentrates on the dental techniques that use the characteristics of teeth as a means of identification of freshly deceased and skeletonised animals. Furthermore, this highlights the information that can be extracted about the animal from the post-mortem dental profile.

Digital Reconstructions Using Linear Regression: How Well Can It Estimate Missing Shape Data from Small Damaged Areas?

Skeletal remains analyzed by anthropologists, paleontologists and forensic scientists are usually found fragmented or incomplete. Accurate estimations of the original morphologies are a challenge for which several digital reconstruction methods have been proposed. In this study, the accuracy of reconstructing bones based on multiple linear regression (RM) was tested. A total of 150 digital models from complete zygomatics from recent past populations (European and African American) were studied using high-density geometric morphometrics. Some landmarks (i.e., 2, 3 and 6) were coded as missing to simulate incomplete zygomatics and the missing landmarks were estimated with RM. In the zygomatics, this simulated damage affects a few square centimeters or less. Finally, the predicted and original shape data were compared. The results indicate that the predicted landmark coordinates were significantly different from the original ones, although this difference was less than the difference between the original zygomatic and the mean zygomatic in the sample. The performance of the method was affected by the location and the number of missing landmarks, with decreasing accuracy with increasing damaged area. We conclude that RM can accurately estimate the original appearance of the zygomatics when the damage is small.

Correlation coefficients for predicting canine diameters from premolar and molar sizes.

BACKGROUND/PURPOSE: The permanent canine is the most widely used tooth for sex estimation because it is the tooth with the highest degree of sexual dimorphism; however, there are several factors that can limit the analysis (e.g., pathologies, postmortem loss). The aim of this work was to analyse the correlation between the dimensions of the canines and those of the premolars and molars, and evaluate the correspondence of real and predicted canine dimensions by applying the equations developed. MATERIALS AND METHODS: The sample was composed of digital models of 80 adult individuals from Temuco, Chile. The buccolingual and mesiodistal diameters of the canine, premolar and molar dental crowns were measured and Pearson's linear regression analysis was performed in order to determine the correlation between the diameters. The equations obtained from the reference subsample were applied to a validation subsample to predict canine dimensions from the dimensions of the postcanine teeth. RESULTS: Four regression equations were obtained, all for prediction of the size of the lower canines, whose correlation coefficient ranged from 0.701 to 0.738. The regression equations developed with the reference sample were tested on the validation sample using a Student's t-test for paired samples and the intraclass correlation coefficient. The differences between actual dental size and that predicted by the equations were not significantly different, and concordance analysis showed a moderate degree (0.485-0.585). CONCLUSION: There is a limited correlation of canine dimensions with respect to premolars and molars. The correspondence between the actual and predicted canines dimensions is moderate.

Sexual dimorphism of the maxillary postcanine dentition: A geometric morphometric analysis.

The aim of this work was to study the sexual dimorphism of the occlusal surface of the maxillary postcanine dentition using geometric morphometric techniques. This study evaluated 139 individuals as part of five osteological collections from municipal cemeteries in the province of Granada (Spain). The landmarks and semilandmarks were analysed by principal components analysis, canonical variate analysis and discriminant analysis. Only the fourth maxillary premolar showed significant sexual dimorphism; however, cross-validation values for shape variables were 64.44% for males and 63.60% for females and 60.17% for males and 60.99% for females when both shape and size variables were considered. The third maxillary premolar and first and second maxillary molars did not show significant sexual dimorphism. The results show that maxillary postcanine dentition cannot assist in sex estimation, either only shape or shape and size.

Lip print identification: Current perspectives.

Lip print identification has been proposed as an additional tool for crime investigation because of the supposed uniqueness of labial grooves; however, critics of the validity and reliability for methods and techniques redefined standards and requirements in order to consider this discipline a real forensic identification science. During our research we identified recent literature, presented here, which although extensive, have focused almost entirely on anthropological topics with outdated references which were not from primary sources and, furthermore, were erroneously quoted. Currently, authors continue to use the concept of lip pattern uniqueness, yet the greatest part of their research has failed to support this hypothesis under current scientific standards. Concepts and designs needed to evaluate materials for lip print development - the isolation of DNA, evaluation of inter-rater reliability in identifying their patterns or known potential rate of error - are scarcely mentioned in the reviewed literature. Lip print identification has been important historically, but the new paradigm makes the redefinition of the current research necessary to stop guesswork and speculation.

Sexual dimorphism of the first deciduous molar: A geometric morphometric approach.

Estimating the sex of immature skeletal remains is important when reconstructing the biological profile of unknown individuals in anthropological practice. Teeth have a distinct importance as they are the most frequently recovered physical elements of an individual. They persist after death due to their hardness and resistance to postmortem insults. The aim of this study was to analyse the sexual dimorphism of the occlusal surface of the first deciduous molar using geometric morphometric techniques. This study evaluated 38 first maxillary deciduous molars (21 males, 17 females) and 30 first mandibular deciduous molars (15 males, 15 females) from the Granada osteological collection of identified subadults (Granada, Spain). The landmark and semilandmark coordinates were analysed by principal components analysis, canonical variate analysis and discriminant analysis. Only the first maxillary deciduous molar showed a significant sexual dimorphism, with cross-validation values for shape variables of 93.23% for males and 83.17% for females, and 100% for males and 87.50% for females when both shape and size variables were considered. Despite there being acceptable cross-validation classification for the first mandibular deciduous molar (82.35% for males and 92.31% for females for shape variables and 82.35% for males and 92.31% for females for shape and size variables), no significant differences indicating sexual dimorphism were identified. The results show that the first upper deciduous molar can assist in sex estimation, and that geometric morphometric analysis is a suitable technique to answer questions related to shape that cannot be observed with the naked eye.

Specific-age group sex estimation of infants through geometric morphometrics analysis of pubis and ischium.

Sex determination of unknown individuals is one of the primary goals of Physical and Forensic Anthropology. The adult skeleton can be sexed using both morphological and metric traits on a large number of bones. The human pelvis is often used as an important element of adult sex determination. However, studies carried out about the pelvic bone in subadult individuals present several limitations due the absence of sexually dimorphic characteristics. In this study, we analyse the sexual dimorphism of the immature pubis and ischium bones, attending to their shape (Procrustes residuals) and size (centroid size), using an identified sample of subadult individuals composed of 58 individuals for the pubis and 83 for the ischium, aged between birth and 1year of life, from the Granada osteological collection of identified infants (Granada, Spain). Geometric morphometric methods and discriminant analysis were applied to this study. The results of intra- and inter-observer error showed good and excellent agreement in the location of coordinates of landmarks and semilandmarks, respectively. Principal component analysis performed on shape and size variables showed superposition of the two sexes, suggesting a low degree of sexual dimorphism. Canonical variable analysis did not show significant changes between the male and female shapes. As a consequence, discriminant analysis with leave-one-out cross validation provided low classification accuracy. The results suggested a low degree of sexual dimorphism supported by significant sexual dimorphism in the subadult sample and poor cross-validated classification accuracy. The inclusion of centroid size as a discriminant variable does not imply a significant improvement in the results of the analysis. The similarities found between the sexes prevent consideration of pubic and ischial morphology as a sex estimator in early stages of development. The authors suggest extending this study by analysing the different trajectories of shape and size in later ontogeny between males and females.