Cranial trauma in handgun executions: Circumferential delamination defect and its relationship with contact/close-range shooting.

Skeletal evidence usually constitutes the only source of information to interpret lesion patterns that help to clarify the circumstances surrounding death. The examination and interpretation of bone trauma are essential to the application and utility of anthropology as a forensic science. When discussing the effect of gunshot wounds in bone, it becomes imperative to differentiate between short and long-distance injuries based on clear, distinct, and observable signs. To contribute to the debate, our focus is directed toward the external analysis of the so-called circumferential delamination defect (CDD) as an observable proxy for close-range shooting (≤30 cm) and contact gunshot wounds in the skull. In the context of known extrajudicial killings, in which the perpetrators used short 9 × 19 FMJ ammunition in a close-range shooting, instances of CDD have been documented. Empirical evidence reinforcing the causal relationship between CDD and close-range shootings is presented. Elements' characteristics of firearm residues were also found in remains buried for up to 30 years. Primarily, this work shows that the concentrations of gunshot residues (Pb, Ba, and Sb) resemble those observed in fresh corpses with the same gunshot wound (GSW). Moreover, the correlation observed between CDD and gunshot residues, where the likelihood of CDD increases the closer to the head and the more perpendicular the shot angle is, reinforces CDD as a pivotal discriminatory factor in the skeletal evidence of short-range or contact shot. This research contributes to the field of forensic anthropology by providing fundamental insights into the etiology of CDD and its practical application.

Evaluación métrica de caninos permanentes para la estimación sexual en la Colección “Prof. Dr. Rómulo Lambre”, Buenos Aires, Argentina / Metric evaluation of permanent canines for sexual estimation in the Collection “Prof. Dr. Romulo Lambre”, Buenos Aires, Argentina

Introducción la estimación del sexo es un aspecto fundamental de la labor forense, ya que constituye un paso obligatorio para la identificación de restos humanos de procedencia desconocida. El análisis metodológico de la dentición como estimador sexual reviste importancia debido al elevado grado de preservación de los dientes. Considerando la necesidad de contar con información concreta respecto del potencial de la dentición en la estimación del sexo en casos locales de Argentina, el objetivo del presente estudio es evaluar la propuesta previamente desarrollada por Luna (2019) en una muestra local de restos esqueléticos humanos. Materiales y métodos se seleccionó una muestra de 152 caninos permanentes pertenecientes a 98 individuos de ambos sexos que forman parte de la colección osteológica Profesor Dr. Rómulo Lambre (La Plata, Argentina). Posteriormente se aplicó la propuesta de Luna (2019) para la estimación del sexo a partir de la métrica de la corona y del cuello de los caninos, la cual considera las medidas directas y los diferentes tipos de funciones discriminantes y regresiones logísticas. Resultados de las medidas directas consideradas, solo el diámetro mesiodistal cervical ofreció resultados aceptables (>75%) para la estimación sexual. Asimismo, únicamente la función discriminante 1 presentó probabilidades a posteriori de clasificaciones correctas superiores a 0,75 y las regresiones logísticas 1 y 3 exhibieron resultados generales satisfactorios. Conclusiones esta propuesta basada en el estudio métrico de caninos permanentes constituye una alternativa metodológica adecuada en situaciones en las cuales los elementos óseos diagnósticos del sexo se encuentran deteriorados o ausentes. (AU)

Introduction Sex estimation is a fundamental aspect of forensic work as a mandatory step for the identification of human remains of unknown origin. The methodological analysis of the dentition as a sexual estimator is important due to its high degree of preservation. Considering the need for specific information regarding the potential of dentition for sex estimation in forensic cases from Argentina, the aim of this study is to evaluate the proposal previously developed by Luna (2019) in a local sample of human skeletal remains. Materials and methods A sample of 152 permanent canines belonging to 98 individuals of both sexes was selected- The individuals belong to the Prof. Dr. Rómulo Lambre osteological collection (La Plata, Argentina). Luna's proposal (2019) was applied to estimate sex from canine crown and neck metrics, which considers direct measurements and different types of discriminant functions and logistic regressions. Results Only the cervical mesiodistal diameter showed acceptable results (>75%) for sex estimation. Moreover, discriminant function 1 showed a posteriori probabilities of correct classifications greater than 0.75 and logistic regressions 1 and 3 offered acceptable overall results. Conclusions This proposal based on the metric recording of permanent canines constitutes an adequate methodological alternative in situations in which the diagnostic bone elements of sex are deteriorated or absent. (AU)

Root dentin translucency and age at death estimation in adults using single rooted teeth: Update of the Forensic International Dental Database.

Since the publication of Lamendin's age estimation technique, the root dentin translucency has received increasing attention as an important indicator of age. Recently, Parra and colleagues presented the Forensic International Dental Database (FIDB), a proposal to estimate age at death in adults based on Bayes theorem by applying the criteria of Lamendin's technique. The present study aims to update the procedure and to evaluate a new version of the method (named FIDBv2) using two control samples from Colombia and Greece. The performance of this new version was acceptable and suggests that the method is suitable for age at death estimation in adult individuals from different forensic contexts. The best approximations to chronological age were obtained for individuals between 30 and 60 years old, with errors less than 10 years. The age estimations calculated on control samples suggest the adequate performance of FIDBv2 on individuals from varied populations. It can be stated that the FIDBv2 constitutes a solid alternative to be used in contexts where no additional data are available. Here we reinforce the initial idea that this model for estimating age at death in adults may be generalizable to any forensic context in the world.

Age-at-death estimation in adults using three forensic methodologies: A Lamendin's technique approach for Latin American context and the extension of a forensic international dental database.

In forensic science, the information that teeth provide to the age estimation process is very important. In adults, one of the most widely used indicators of skeletal age is the Root Dentin Translucency (RDT), mainly through the Lamendin technique, which is used in various Latin American contexts. Recently, Parra et al. (2020) have developed a Bayesian regression model using the Lamendin technique to establish standardized criteria for estimating age-at-death in adults in various forensic contexts. In this study, we evaluate the applicability of this proposal together with the proposal by Lamendin et al. (1992) and Prince and Ubelaker (2002) in Latin American contexts. A sample of single-rooted teeth belonging to 805 individuals from six Latin American countries was used. The results of the three proposals considered were analyzed taking into account factors such as age, sex, origin, and the tooth surface on which the variables were surveyed. Of the factors that would affect the estimates, it was found that the age of the individuals had the greatest influence. However, it was confirmed that the sex and surface of the teeth on which the measurements were taken did not influence the final result. On the other hand, as we expected, the application of the analyzed proposals would also be possible in other forensic contexts, as shown by the results obtained according to the origin. This research expands the FIDB with more information on Latino contexts.

Calidad ósea en poblaciones contemporáneas. Análisis de la estructura trabecular calcánea en una muestra esqueletal / Bone Quality in Contem porary Populations. Calcaneal Trabecular Structure Analysis in a Skeletal Sample

Resumen Objetivo: La osteoporosis es una condición de relevancia a nivel epidemiológico en Argentina, así como en el resto del mundo. Si bien actualmente la herramienta diagnóstica más relevante es la densitometría ósea, los análisis radiológicos pueden aportar información, principalmente en lo referente a la calidad ósea. En ese sentido, nos proponemos evaluar la estructura trabecular calcánea de una población local. Métodos: El material para dicho estudio consistió en 91 calcáneos de esqueletos pertenecientes a una muestra esqueletal. Fueron analizados individuos adultos, de ambos sexos, mediante imágenes radiográficas, a fin de clasificar su estructura trabecular de acuerdo al índice propuesto por Jhamaria y col., en una escala de V (normal) a I (osteoporosis severa). Resultados: Las prevalencias estimadas fueron de 23,1% de osteoporosis (fases I y II), 16,5% de borderline (fase III) y 48,4% se clasificó como estructura trabecular normal (fases IV y V). En relación a la edad de los individuos, se encontró una correlación significativa negativa entre ella y la pérdida trabecular (tau-b = -0,524, p = 0,00). No se encontraron diferencias significativas en cuanto a la afección dimórfica de la patología. Discusión: La relación entre envejecimiento y osteoporosis hallada es coincidente con estudios nacionales e internacionales que reconocen una disminución en la densidad mineral ósea (DMO) y una mala calidad ósea en individuos adultos mayores. La ausencia de afección dimórfica podría deberse a la edad promedio de la muestra, sumada a la posible resistencia de la estructura esponjosa del calcáneo a los cambios generados por el déficit estrogénico en las mujeres, característica de la osteoporosis tipo I. Conclusión: Creemos que es necesario revalorizar el análisis óseo por medio de radiografías, puesto que pueden ser de utilidad tanto en la clínica como en la investigación básica, debido a la mayor disponibilidad de equipos y a que posibilitan el análisis de otras propiedades del tejido óseo.

Abstract Objective: Osteoporosis is an important condition in an epidemiologic level in Argentina as in the rest of the world. Even though nowadays the most relevant diagnostic technique is bone densitometry, radiological studies can provide useful information, mainly in relation to bone quality. For this purpose, we aim to evaluate the calcaneus trabecular structure in a contemporary local population. Methods: The sample for this study consisted of 91 calcaneus from skeletons belonging to the skeletal repository. Adult individuals from both sexes were analyzed, to classify their trabecular structure according to the index proposed by Jhamaria et al., on a scale of V (normal) to I (severe osteoporosis). Results: The estimated prevalence were 23,1% of osteoporosis (phase I and II), 16,5% of borderline (phase III) and 48,4% were classified as normal trabecular structure (phase IV and V). In relation to the age of the individuals, a significant negative correlation was found between the first and the trabecular loss (tau-b = -0.524, p = 0.00). No significant differences were found in relation to the sex prevalence of this pathology. Discussion: The association found between aging and osteoporosis matches with the results of national and international studies that recognize that a decrease in Bone Mineral Density (BMD) and a bad bone quality in older adults. Absence of differences between sexes in this condition could be due to age average of the sample, added to the possible resistance of the calcaneus spongy structure to changes generated by estrogen deficit in women, characteristic of osteoporosis type I. Conclusion: We believe that it is necessary to revalue bone analysis by radiographic means, since they can be of use both in clinic and in basic research, due to a greater equipment availability and because they allow the analysis of other properties of bone tissue.

Maximum length of deciduous dentition as an indicator of age during the first year of life: Methodological validation in a contemporary osteological collection.

Out of all the available methods for estimating age at death from immature human skeletal remains, those based on odontometric variables of deciduous dentition have proved to be one of the most accurate. The development of odontometric methods has been improved through the creation of documented human osteological collections, allowing their validation in different populations. The present study aims to test the regression equations for age estimation proposed by Liversidge et al. 1993, Irurita Olivares et al. 2014, and Cardoso et al. 2019, on the basis of the maximum length of deciduous teeth in an Argentinian sample of 35 infants of known age at death. The results showed that the absolute mean difference between estimated and chronological age was 5.76±6.33 weeks for Liversidge's method, 5.71±6.41 weeks for Irurita Olivares's method, and 6.79±5.80 for Cardoso's method. It was also found that, for Liversidge's method, the canines provided the most accurate and the least biased estimations. For Irurita Olivares's method, mandibular anterior teeth were the most accurate, while the first mandibular molars offered the least biased estimations. For Cardoso's method, the canines presented the most accurate estimations, while the lateral incisors the least biased ones. Finally, 95% confidence intervals of estimated ages were calculated for each method, finding that Irurita Olivares's method provided the most reliable age estimations when using mandibular central incisors and mandibular first molars.