Bone histomorphometry of the clavicle in a forensic sample from Albania

Forensic assessment of skeletal material includes age estimation of unknown individuals. When dealing with extremely fragmented human remains that lack macro-features used in age estimation, histological assessment of the skeletal elements can be employed. Historically, microscopic methods for age assessment used by forensic anthropologists have been available since 1965. Several skeletal elements have been used for this purpose. Among them, the clavicle has garnered very little attention. The purpose of this study is to explore the validity of clavicular histomorphometry as an age marker in a modern Balkan sample. This study examined a modern clavicular autopsy sample from Albania. The sample consisted of 33 individuals of known age and cause of death. Data were collected for micro-anatomical features including osteon population density (OPD) and cortical area. Intra- and inter-observer errors were assessed through technical error of measurement (TEM) and R coefficient. A validation study was performed in order to test the accuracy of existing histological formulae. Regression analysis was run to developed age prediction models with the best models tested through cross-validation and the comparison between OPD for the Albanian sample and a European-American sample examined. Intra- and inter-observer error TEM results demonstrated values falling within the limits of acceptance. The existing histological methods did not perform accurately on the sample under study. Regression equations for Albanians produced age estimations deviating 8 and 11 years from known age. Cross-validation on the most accurate regression formula which includes OPD as a single variable demonstrated similar mean errors. Statistically significant differences were observed between the Albanian and the European-American population when the two samples were compared. The research presented is the fifth article published and the fifth population explored on clavicular microstructure. The potential of histology to estimate age on the Albanian population is shown here; however, population effect, diet and health status might be considered. Further inclusion of individuals will corroborate our preliminary findings

Estimation of Age-at-Death Using Cortical Bone Histomorphometry of the Rib and Femur: A Validation Study on a British Population

Histomorphometry constitutes a valuable tool for age estimation. Histological interpopulation variability has been shown to affect the accuracy of age estimation techniques and therefore validation studies are required to test the accuracy of the pre-existing methodologies. The present research constitutes a validation study of widely known histological methods on the sixth rib and the femoral midshaft of a 19th century British population originating from Blackburn, England. An evaluation of the histomorphometric features of eleven ribs and five femora was performed and used to test the accuracy of selected methods. Results indicated that osteon area and circularity were the only histomorphometric variables that presented significant interpopulation variability. Cho et al.’s method for the ribs and the average value produced using Kerley and Ubelaker’s method for intact osteon and percentage of lamellar bone equations for femur were considered the only reliable markers for estimating the age on the Blackburn sample. In the case of old individuals, Goliath et al.’s method provided more satisfactory results. Overall, the present study provides evidence on the applicability of the aging histomorphometric methods on a British sample and highlights the limitations of applying histomorphometric methods developed on different reference populations than the one under investigation

FORDISC® and AncesTrees:Limitations and Considerations for the Identification of Individuals From Central and South America

Learning Overview: The goal of this presentation is to present new data on population structure and population history from individuals from Central and South America through the interpretation of population-affinity estimations obtained by two online applications (FORDISC® and AncesTrees).Impact Statement: This presentation will impact the forensic science community by providing forensic practitioners with a theoretical and practical background for the application of two popular online softwares, FORDISC® and AncesTrees, targeting issues for population-affinity estimations on human remains from Central and South American. Extreme conditions leading to rapid skeletonization in some areas of the United States-Mexico border can make identification difficult. From the demographics gathered for biological profile estimation, biogeographical origin can impact the choice of subsequent methods for sex or age-at-death assessment. AncesTrees and FORDISC® are two computerized statistically based methods for estimating population affinity. To determine the reliability of group allocation using these applications, different target samples should be tested.The aim of this study is to explore the reliability of these applications in estimating the origin of individuals from Central and South America, comprising population groups that likely form the migratory flow prevalent across the United States-Mexico border. A total of 50 adult individuals (25 males and 25 females) identified as Mexican, Mexican American, Hispanic, New Mexican, or Latino were selected from the New Mexico Decedent Image Database. Seventeen cranial measurements were collected from Computed Tomography (CT) scans. Compiled measurements followed protocols outlined by AncesTrees and FORDISC®. Parameter values were inserted into the online platforms, with the settings for the application determined as non-prior background information.For FORDISC®, both the Howells’ and the Forensic Anthropology Data Bank (FDB) datasets were tested to explore any potential differences related to the chronology of the reference samples, as well as allowing for a comparison between AncesTrees and FORDISC® historical samples. All allocations are reported in the results, with Posterior Probability (PP) and Group Membership (GM) with values ≥0.80 being considered for further interpretation of the group allocation.Results show that AncesTrees allocated individuals as European (48%) and East Asian (32%), with the remaining biogeographical population sample allocations representing less than 10%. For the FORDISC® FDB, 26% of the sample was estimated as White and 24% of the sample was allocated as Hispanic, with the third-highest number of individuals being associated to Japanese (16%), Guatemalan (12%) and Chinese (12%) samples. Regarding the FORDISC® historical dataset, 24% of the individuals were classified as European with the next highest allocation being for East Asian samples (40%). Very few individuals obtained a PP higher than the threshold for FORDISC® estimations while GM for AncesTrees was over 0.80 for around 62% of the sampleAn accurate reconstruction of the biological profile is crucial for positive identification. Most of the population allocations obtained here using two commonly used online platforms present trends that suggest individuals from Central and South American origin would fall within Hispanic and European populations as well as East Asian samples. This research provides insights on population structure and population histories, as the patterns observed may be linked to social and political history. Future research, including larger and more diverse samples, will confirm our results and provide further information on human variation and inter-population differences.A consensus on the terminology as well as a revision of the information used for grouping the samples is recommended to ensure consistency between forensic practitioners and researchers. Moreover, larger and more representative datasets are needed to increase the accuracy and reliability of identification of unknown individuals in a forensic context, especially for areas with high migration flows such as the United States-Mexico border

FORDISC® and AncesTrees:Limitations and Considerations for the Identification of Individuals From Central and South America

Learning Overview: The goal of this presentation is to present new data on population structure and population history from individuals from Central and South America through the interpretation of population-affinity estimations obtained by two online applications (FORDISC® and AncesTrees).Impact Statement: This presentation will impact the forensic science community by providing forensic practitioners with a theoretical and practical background for the application of two popular online softwares, FORDISC® and AncesTrees, targeting issues for population-affinity estimations on human remains from Central and South American. Extreme conditions leading to rapid skeletonization in some areas of the United States-Mexico border can make identification difficult. From the demographics gathered for biological profile estimation, biogeographical origin can impact the choice of subsequent methods for sex or age-at-death assessment. AncesTrees and FORDISC® are two computerized statistically based methods for estimating population affinity. To determine the reliability of group allocation using these applications, different target samples should be tested.The aim of this study is to explore the reliability of these applications in estimating the origin of individuals from Central and South America, comprising population groups that likely form the migratory flow prevalent across the United States-Mexico border. A total of 50 adult individuals (25 males and 25 females) identified as Mexican, Mexican American, Hispanic, New Mexican, or Latino were selected from the New Mexico Decedent Image Database. Seventeen cranial measurements were collected from Computed Tomography (CT) scans. Compiled measurements followed protocols outlined by AncesTrees and FORDISC®. Parameter values were inserted into the online platforms, with the settings for the application determined as non-prior background information.For FORDISC®, both the Howells’ and the Forensic Anthropology Data Bank (FDB) datasets were tested to explore any potential differences related to the chronology of the reference samples, as well as allowing for a comparison between AncesTrees and FORDISC® historical samples. All allocations are reported in the results, with Posterior Probability (PP) and Group Membership (GM) with values ≥0.80 being considered for further interpretation of the group allocation.Results show that AncesTrees allocated individuals as European (48%) and East Asian (32%), with the remaining biogeographical population sample allocations representing less than 10%. For the FORDISC® FDB, 26% of the sample was estimated as White and 24% of the sample was allocated as Hispanic, with the third-highest number of individuals being associated to Japanese (16%), Guatemalan (12%) and Chinese (12%) samples. Regarding the FORDISC® historical dataset, 24% of the individuals were classified as European with the next highest allocation being for East Asian samples (40%). Very few individuals obtained a PP higher than the threshold for FORDISC® estimations while GM for AncesTrees was over 0.80 for around 62% of the sampleAn accurate reconstruction of the biological profile is crucial for positive identification. Most of the population allocations obtained here using two commonly used online platforms present trends that suggest individuals from Central and South American origin would fall within Hispanic and European populations as well as East Asian samples. This research provides insights on population structure and population histories, as the patterns observed may be linked to social and political history. Future research, including larger and more diverse samples, will confirm our results and provide further information on human variation and inter-population differences.A consensus on the terminology as well as a revision of the information used for grouping the samples is recommended to ensure consistency between forensic practitioners and researchers. Moreover, larger and more representative datasets are needed to increase the accuracy and reliability of identification of unknown individuals in a forensic context, especially for areas with high migration flows such as the United States-Mexico border

Current Practice and the Validity of Stature Estimation Within the United Kingdom and Ireland

"Analysis of the morphology, condition and standard measurements of skeletal remains are used to estimate the four components of the biological profile: age, ancestry, sex and stature. It has been suggested that stature estimation is the least valuable aspect of the biological profile (Parsons, 2017). Stature methods within the United Kingdom and Ireland were surveyed, via questionnaire, to understand current practice and stature’s perceived value as a discriminator in identifying unknown human remains. There were 16 responses which were grouped into forensic anthropologists (7) and archaeologists (9). The forensic anthropology group evidenced higher levels of certification (RAI and CIFA), while the archaeologists had more years of experience and a higher frequency of stature estimation each year. Respondents ranked stature as the least important part of the biological profile on 4 occasions and the second least important on 12 occasions. 75% of respondents stated that they used equations developed by Trotter and Gleser (1952; 1958; 1971), described as 'the accepted standard'. Only three respondents referred to guidelines. 56% of respondents had teaching commitments where the traditional methods were commonly taught. Qualified and experienced practitioners rated stature of low discriminatory value within the modern or archaeological populations. There was little acknowledgement of newer work or utilisation of guidelines. To strengthen the discipline of forensic anthropology in the United Kingdom, further research is required to establish the status and validity of stature estimation in forensic identification.References: Parsons, H.R. (2017) The Accuracy of the Biological Profile in Casework: An Analysis of Forensic Anthropology Reports in Three Medical Examiners’ Offices PhD Thesis. University of Tennessee. Trotter, M., Gleser, G.C. (1952) Estimation of Stature from Long Bones of American Whites and Negroes. American Journal of Physical Anthropology, 10: 463-514. Trotter, M., Gleser, G.C. (1958) A Re-evaluation of Estimation of Stature Based on Measurements of Stature Taken During Life and of the Long Bones After Death. American Journal of Physical Anthropology, 16: 79-124. Trotter, M. (1971) ‘Estimation of Stature from Intact Long Limb Bones’ in Stewart, T (ed.) Personal Identification in Mass Disasters, City of Washington: National Museum of Natural History, 71-8

Exploring age-related trends in cortical and trabecular bone in an elderly Scottish sample:a pilot study on the clavicle

The human lifespan is increasing globally, increasing the need for further research on age-related changes inthe bone of elderly individuals. Microscopic assessment of the skeletal system can provide information aboutthe composition, mechanical, and functional properties of bone. The aim of this study is to combine 2D and3D approaches examining cortical and trabecular bone to explore histological age-related changes in theclavicles of an elderly Scottish population.The medial portion of 30 left clavicles was collected from Scottish donors from the Centre of Anatomy andHuman Identification. The sample had a mean age of 83 years, with a sex distribution of 15 males and 15females. Histomorphometric variables from the trabecular and cortical bone were collected. Five trabecularparameters were assessed using micro-CT scanning on two volumes of interest (VOI-superior and inferiorsampling locations on the medial clavicular end). On the cortical bone, fourteen parameters were evaluatedusing traditional histological techniques. Cortical area related parameters were assessed on the whole crosssection, while osteon frequency related variables were measured on 8 sampling areas targeting keyanatomical locations on the periosteal section of the clavicle.Intra-observer error was assessed using intra-class correlation coefficient. The two VOIs were compared forstatistical differences using paired t-test or Wilcoxon signed-rank test. Pearson and Spearman correlationcoefficients were calculated, and age group comparisons were conducted for all parameters on the entiresample, the sample divided by decades (70s, 80s, and 90s), and the sample divided into two age groups(over/under 85 years). Sex differences were explored using an independent t-test and Mann-Whitney test.Lastly, stepwise regression analysis was used to test the optimal combination of parameters that couldexplain the highest variation in age.Intra-observer error demonstrated overall good reliability for most parameters. Only bone volume fractiondid not differ between VOIs, with all other trabecular parameters showing statistically significant differences.Cortical area parameters (cortical area and relative cortical area), intact osteon number, and both VOIs fortrabecular connectivity density were statistically significantly correlated to age. When the sample was splitinto decades, no significant changes were observed over the three decadesfor cortical bone parameters (70s,80s, and 90s). However, trabecular thickness and bone volume fraction differed statistically betweenindividuals in their 70s and 80s. When the over/under 85 years groups were compared, only relative corticalarea was statistically different between the two groups. Sex differences were found for cortical area relatedparameters (total area, endosteal area, and cortical area). Stepwise multiple linear regression showed thatrelative cortical area and inferior trabecular connectivity accounted for 30% of the variation in age.This research showed that combining both cortical and trabecular bone using histomorphometric parameterscan provide valuable information about age-related changes, suggesting also that other factors such as sexor age-related pathologies might have an impact on the changes observed in the two bone tissue types. Whilefurther research is necessary, this study adds to the growing research on bone histology using differentpopulations and exploring the ageing patterns of an elderly population