Age-At-Death Estimation

This study aims to develop age-at-death standards for Valley of Mexico skeletal collections. Using 159 individuals, with a dental age-at-death between 0 to 15 years, we develop linear and quadratic inverse regression models of age-atdeath estimation between dental age and the diaphyseal length of the six long bones. A blind test for both regressions was performed, also a regression developed for a Maya group was carried out. We also compared skeletal growth of our sample by applying regressions developed for Maya and North American populations to assess the magnitude of the differences among ethnically unrelated populations. Our regressions yielded a close correlation between the diaphyseal length and dental age, especially femur and radius. It is noticeable that the disparities between younger and older age categories, the latter presenting larger standard deviations. Quadratic regression fitted better than linear and Maya regressions, and the differences of age-at-death distributions are significant. The skeletal growth curve of the Valley of Mexico is statistically different from other Native American groups. We conclude that for the present standards, despite the high degree of variance, the quadratic regression is a better applicable age estimator, when it is applied to biologically close populations.

Bone proteomic studies using animal proxies and skeletonized human remains have delivered encouraging results in the search for potential biomarkers for precise and accurate post-mortem interval (PMI) and the age-at-death (AAD) estimation in medico-legal investigations. The development of forensic proteo-mics for PMI and AAD estimation is in critical need of research on human remains throughout decomposition, as currently the effects of both inter-individual biological differences and taphonomic alteration on the survival of human bone protein profiles are unclear. This study investigated the human bone proteome in four human body donors studied throughout decomposition outdoors. The effects of ageing phenomena (in vivo and post-mortem) and intrinsic and extrinsic variables on the variety and abundancy of the bone proteome were assessed. Results indicate that taphonomic and biological variables play a significant role in the survival of proteins in bone. Our findings suggest that in...

Este libro se compone de 12 capítulos que tratan sobre diversos aspectos de la arqueología del curso inferior del Río Colorado (Pcia. de Buenos Aires), en la transición pampeano-patagónica oriental. El objetivo central del mismo es sintetizar el conocimiento obtenido sobre los modos de vida, la trayectoria histórica y la organización social de las sociedades cazadoras-recolectoras que habitaron este sector de la cuenca durante los últimos ca. 6000 años AP.

Establishing ancestry from a skeleton for forensic purposes has been shown to be difficult. The purpose of
this paper is to address the application of thirteen non-metric traits to estimate ancestry in three South
African groups, namely White, Black and ‘‘Coloured’’. In doing so, the frequency distribution of thirteen
non-metric traits among South Africans are presented; the relationship of these non-metric traits with
ancestry, sex, age at death are evaluated; and Kappa statistics are utilized to assess the inter and intrarater
reliability. Crania of 520 known individuals were obtained from four skeletal samples in South
Africa: the Pretoria Bone Collection, the Raymond A. Dart Collection, the Kirsten Collection and the
Student Bone Collection from the University of the Free State. Average age at death was 51, with an age
range between 18 and 90. Thirteen commonly used non-metric traits from the face and jaw were scored;
definition and illustrations were taken from Hefner [2], Bass [6] and Hauser and De Stephano [7].
Frequency distributions, ordinal regression and Cohen’s Kappa statistics were performed as a means to
assess population variation and repeatability. Frequency distributions were highly variable among South
Africans. Twelve of the 13 variables had a statistically significant relationship with ancestry. Sex
significantly affected only one variable, inter-orbital breadth, and age at death affected two (anterior
nasal spine and alveolar prognathism). The interaction of ancestry and sex independently affected three
variables (nasal bone contour, nasal breadth, and interorbital breadth). Seven traits had moderate to
excellent repeatability, while poor scoring consistency was noted for six variables. Difficulties in
repeating several of the trait scores may require either a need for refinement of the definitions, or these
character states may not adequately describe the observable morphology in the population. The
application of the traditional experience-based approach for estimating ancestry in forensic case work is
problematic.

Bone proteomic studies using animal proxies and skeletonized human remains have delivered encouraging results in the search for potential biomarkers for precise and accurate postmortem interval (PMI) and the age-at-death (AAD) estimation in medico-legal investigations. The development of forensic proteomics for PMI and AAD estimation is in critical need of research on human remains throughout decomposition, as currently the effects of both inter-individual biological differences and taphonomic alteration on the survival of human bone protein profiles are unclear. This study investigated the human bone proteome in four human body donors studied throughout decomposition outdoors. The effects of ageing phenomena (in vivo and post-mortem) and intrinsic and extrinsic variables on the variety and abundancy of the bone proteome were assessed. Results indicate that taphonomic and biological variables play a significant role in the survival of proteins in bone. Our findings suggest that inter-individual and inter-skeletal differences in bone mineral density (BMD) are important variables affecting the survival of proteins. Specific proteins survive better within the mineral matrix due to their mineralbinding properties. The mineral matrix likely also protects these proteins by restricting the movement of decomposer microbes. New potential biomarkers for PMI estimation and AAD estimation were identified. Future development of forensic bone proteomics should include standard measurement of BMD and target a combination of different biomarkers.

Adli antropoloji, insan kemiklerinden biyolojik profil oluşturulan bir bilim dalıdır. İnsan kemiklerinden biyolojik profil elde etme safhalarının en önemlilerinden biri, bireyin ölüm zamanındaki yaşını tespit etmektir. Antropologlar yaş belirlemek için erişkin olmayan ve erişkin bireylerde farklı yöntemler kullanmakta ve erişkin bireylerin cinsiyetine göre değişen çeşitli metotlar uygulamaktadırlar. Bu metotlar genel olarak dental, osteolojik, histolojik ve kompozit metotları içermektedir. Bu makalede, insan iskeletlerinin incelendiği vakalarda ölüm zamanındaki yaş tahmininde kullanılan geleneksel ve popüler metotlardan, bu metotların uygulanabilirliğinden ve bazı durumlarda karşılaşılan zorluklardan bahsedilecektir.
Anahtar Kelimeler: Adli antropoloji, yaş tahmini, ölüm zamanındaki yaş, iskelet yaşlandırma metotları

Age Estimation Methods in Forensic Anthropology:
Forensic anthropology is a branch of science that biological profiles can be established from human bones. One of the most important phases in establishing biological profile from human bones is to determine the age of the individuals at the time of death. Anthropologists use various methods to determine age in sub-adult and adult individuals, and apply various techniques according to the sex of adult individuals. The age estimation methods generally include dental, osteological, histological and composite methods. This article will discuss the utility and the challenges of traditional and popular methods and techniques used to estimate the age at death where human skeletons are examined.
Keywords: Forensic anthropology, age estimation, age at death, skeletal aging methods

The aim of this paper is to present a method to facilitate age-at-death estimation of older individuals (generally those aged 50+ years) in a representative cemetery sample. The purpose of disaggregating catch-all categories, such as 50+ years, is to enable the exploration of the elderly (those in their 50s, 60s, 70s or 80s) in the context of mortuary archaeology, bioarchaeology and/or palaeopathology. The methodological steps include (1) assessment of occlusal tooth wear in an Anglo Saxon cemetery sample from Worthy Park, UK; (2) seriation of the sample, from relatively youngest to oldest, based on the degree of tooth wear; (3) selection of an ethnographically derived model (known mortality profile) by which seriated individuals in the Worthy Park sample could be reallocated to more realistic or appropriate age classes; (4) reallocation of individuals in the seriated Worthy Park sample to the model age classes. A Hadza, Tanzania, hunter-gatherer profile was chosen to model the Worthy Park sample, although others are available. Using this model, some 66% of the entire adult sample, originally allocated to the single final age category 45+ years, was distributed across four new age categories from the mid-40s to mid-70s. Relatively straightforward, this approach provides a way to identify those individuals, 50+ years old, not normally sensitive to traditional age-at-death estimation methodologies currently available.

The review of historic, ethnographic and modern references of dairy husbandry The review of historical, ethnographic and modern dairy systems will provide a reference for the lactation process mechanism for sheep, goats and cattle. This is important to consider particularly for cattle as the presence of a calf to stimulate milk production is a much debated subject (

Osteoarthritis (OA) is a marker of degeneration within the skeleton, frequently associated with age. This study quantifies the correlation between OA and age-at-death and investigates the utility of shoulder OA as a forensic age indicator using a modern North American sample of 206 individuals. Lipping, surface porosity, osteophyte formation, eburnation, and percentage of joint surface affected were recorded on an ordinal scale and summed to create composite scores that were assigned a specific phase. Spearman's correlation indicated a positive relationship between each composite score and age (right shoulder = 0.752; left shoulder = 0.734). Transition analysis revealed a tendency toward earlier degeneration of the right shoulder. Bayesian statistics generated phase-related age estimates based on highest posterior density regions. Best age estimates were into the seventh decade at the 90th and 50th percentile. The proposed method supplements traditional techniques by providing age estimates beyond a homogenous 50+ age cohort.

Estimating age of death for adult skeletons with accuracy is still one of the chief predicaments in bioanthropology. It has been recognized that methods’ inaccurate results from the lack of a better understanding of the ageing process and associated
confounding factors. In the present study was investigated if body size (measured by stature, body mass, robusticity and articulation size) affects age-related morphological criteria of the pubic symphysis, auricular surface of the iliac and acetabulum. Adult individuals of both sexes with age at death superior to 17 years old were analysed from the Identified Skeletal Collection from the University of Coimbra (Portugal), and the William Bass Donated Skeletal Collection (USA).
Three levels of analysis were followed to evaluate joints degeneration: individual traits, components (weighted linear clustering of correlated traits) and a composite score (sum of all the scores across all characters). Furthermore, stature, body mass and robusticity were computed through femoral measurements, and the surface area of the pelvic joints were calculated from three-dimensional digital polygon objects
created with a white light scanner. A logistic regression analysis was carried out, showing especially body mass, stature and joint surface area affect some of the morphological criteria at the pelvic joints. Robusticity has a minimum effect on the
pelvic joints metamorphosis. Results suggest that smaller individuals tend to age slower, with the transition from a “younger” to an “older” stage occurring at an older age compared with bigger individuals. Different patterns were obtained between population samples, possibly due to body size and age distributions differences between collections, or due to the complex and variable effect body size has in bone
degeneration. The present research shows that body size influences the pelvic joints age-related criteria, which is important to incorporate in future age at death estimation methods.

Today, in most of the countries forensic dental identification is considered as one of the most accurate and reliable method of identification of
human remains. This application of forensic dentistry has proven successful in both single identification cases as well as in multiple fatality
incidents such as world trade center disaster in 2001, the Asian tsunami in December 2004 etc. Comparative dental identification is one of the
primary means of identification along with DNA and fingerprint analysis and also the most common method of identification of human remains.
Identification of human remains from dental records is mandated by the law in some countries. India is one of the most disaster‑prone countries
of the world. It has had some of the world’s most severe droughts, famines, earthquakes, road accidents, and rail accidents. In this paper, few
multiple fatality incidents that took place over the last decade in India are reported. A brief analysis of all the reported cases and difficulties
encountered during identification were discussed. The purpose of this paper is to discuss some of the issues involved in body identifications
following disasters in India. The author also discussed to what extent Indian government is successful in utilizing the expertise of a forensic
dentist in body identifications and also compared the present practice of forensic dental identification in India to Western countries. The goal
is to cite situations and to bring issues into better focus, and hence that the identification procedures can be refined and changes can be made
as necessary.

Age-at-death estimation is one of the most important aspects of bioarchaeological and forensic investigations. A set of analysis carried out with the osteological sample recovered from Chenque I site (Lihué Calel National Park, La Pampa province, Argentina) aims to test the applicability of multiple methods to obtain reliable information about its demographic composition and structure. In the present paper the results of the evaluation of the structure of uniradicular teeth are presented and discussed. It has been previously stated that chronological age is highly correlated with pulp dimensions in these teeth, because dentine deposition continue during all life. Strong correlation has been also identified with periodontal retraction and apical translucency. The analysis of the structure of these teeth offers useful information in order to obtain age-atdeath estimations of the individuals they belonged to. Dental age-at-death estimations of the control sample were obtained evaluating some skeletal markers (pubic symphysis and auricular surface of coxae), and then compared with the dental analysis. The formulae whose results showed strong correlations with the skeletal estimations were applied to another sample, composed of teeth that were not associated with any skeletal marker of age. The evaluation of premolars and lower central incisors offers estimations that are consistent with those obtained from the evaluation of the pelvic bones, so that the application of these formulae is an alternative method to obtain estimations in archaeological samples from similar contexts.

Campanacho V, Cardoso HFV. (2018). The significance of identified human skeletal collections to further our understanding of the skeletal ageing process in adults. In: Charlotte H, Alves-Cardoso F. (Ed.). Identified Skeletal Collections: The testing ground of anthropology?. Oxford, Archaeopress Publishing Ltd: 115-131

The importance of understanding the ageing process with identified skeletal remains The effects of environmental factors on the rate of bone ageing Pregnancy and parturition Drugs and alcohol use Occupation and physical activity Disease and diet Body size
Limitations of identified skeletal collections and their constraints on age estimation research Ethical and legal issues with identified skeletal collections: a Portuguese example

Bioarchaeologists rely on accurate estimations of age-at-death. Clearly, some pathological conditions are associated with gross morphological changes in the skeleton that could impact the effectiveness of age-at-death estimation (i.e. methods based on the pelvis, fourth rib, dental attrition, and cranial stenosis). The magnitude of this problem has not been widely studied due to a paucity of pathological skeletons of known age. We assessed age-at death for three individuals affected by bone dysplasias (achondroplasia, residual rickets, osteogenesis imperfecta) using cementum annulations and several osseous age indicators. We predicted osseous indicators that are based on gross morphological changes would yield age estimates discrepant from the cementochronology. Results demonstrated considerable differences in age estimates between morphological and histological techniques suggesting a need for additional research on the effects of pathology on the accuracy of morphological methods. Conversely, we addressed the proposition that cementum annulations will be inappropriate for age estimation in cases of chronic and severe rhino-maxillary infection and periodontitis. We assessed age-at-death for one individual with leprosy and found no indication the disease process affected cementum formation or preservation. The results of this research indicate the potential value of cementochronology in cases where skeletal pathological conditions constrain the usefulness of traditional age estimation approaches.

Reindeer (Rangifer tarandus) have shaped the cultures and provided livelihood to peoples of the Northern Hemisphere for thousands of years. They are still the socioeconomic cornerstone of many northern cultures. Insight into reindeer mortality patterns is important for understanding past human-reindeer interactions and reindeer population fluctuations in relation to climatic and environmental change. Beyond archaeology, assessing the age structures of modern reindeer populations is important for developing wildlife management strategies. This paper presents a quick, non-destructive and cheap method to estimate age in reindeer in both modern and ancient populations based on tooth wear and eruption patterns of mandibular teeth. We devised the method using a large sample of Svalbard reindeer (Rangifer tarandus platyrhynchus) of known age. We blind-tested the method and tested its applicability on another known-age Svalbard reindeer mandible assemblage. The tests demonstrate our methods' user-friendliness and reliability to generate reproducible, reus-able datasets and accuracy in estimating reindeer age-at-death. K E Y W O R D S Cervidae, dentition-based age estimation, mortality profile, reproducible datasets, Svalbard, zooarchaeological methods

Currently, there are various methods both macroscopic and microscopic, which allow estimating the adult age-at-death with a good accuracy. However, the poor preservation of the archaeological remains prevents us making a good use of these methods from the forensic field, especially in the Maya Low Lands bioarchaeology. In reality, the forensic anthropology seeks for the highest accuracy based on a good preservation, however, what is really required in the archeology is a “robust” method, widely applicable in the degraded bones. In this situation, we offer the “qualitative assessment” of the bone histological structure. We have determined five histomorphological features in our previous studies, and they can be
recognized and recorded even in the most degraded burials. The main objective of this paper lies in examination of those histomorphological features in a modern/colonial sample with known age-at-death. Through our results, we hope to consolidate the concept of the qualification
of the micro-metamorphosis and to let it to be known as a new alternative method of age-at-death determination.

Most age estimation methods are proven problematic when applied in highly fragmented skeletal remains. Rib histomorphometry is advantageous in such cases; yet it is vital to test and revise existing techniques particularly when used in legal settings (Crowder and Rosella, 2007).  This study tested Stout & Paine (1992) and Stout et al. (1994) histological age estimation methods on a Modern Greek sample using different sampling sites.
Six left 4th ribs of known age and sex were selected from a modern skeletal collection. Each rib was cut into three equal segments. Two thin sections were acquired from each segment. A total of 36 thin sections were prepared and analysed. Four variables (cortical area, intact and fragmented osteon density and osteon population density) were calculated for each section and age was estimated according to Stout & Paine (1992) and Stout et al. (1994).
The results showed that both methods produced a systemic underestimation of the individuals (to a maximum of 43 years) although a general improvement in accuracy levels was observed when applying the Stout et al. (1994) formula. There is an increase of error rates with increasing age with the oldest individual showing extreme differences between real age and estimated age.
Comparison of the different sampling sites showed small differences between on the estimated ages suggesting that any fragment of the rib could be used without introducing significant error. Yet, a larger sample should be used to confirm these results.

Key words: Forensic Anthropology, age estimation, Rib histomorphometry, sampling error

The possibility of paleodemographic analysis of 50 samples of Russian urban people dating from the XVII to XIX centuries is analyzed. It is found that age and sex characteristics of most of the samples are distorted. Most skeletal samples come from partially excavated, widely dated cemeteries. The use of traditional morphological methods of age dfinition leads to underestimation of the proportion of the older age cohort, as well as differences in bone preservation and funeral rite underreport the proportion of infants and children under 10 years old. The use of this distorted age-at-death distributions as informative source is subject to availability of historical sources. The differences between paleodemographic characteristics of Russians from European and Siberian towns are consistent with data on higher population growth in Siberia and the impact of migration factor on the age-at-death distribution. Chronological trends in variability of paleodemographic features are explained with historical demography of Russian towns, although the calculated magnitudes of these features likely do not correspond to actual magnitudes.

This study provides regression and classical calibration models for the estimation of age from the dimensions of the metaphyses and epiphyses of the six long bones.

Currently free to access: http://onlinelibrary.wiley.com/doi/10.1002/ajpa.23081/full

The role of the odontologist is crucial for the study of archaeological material. The excavations at the site of the ancient abbey of the Dunes of Koksijde led to the discovery of more than a thousand burial places. It is possible to estimate the age of the skeletons by studying molar dental wear. This method is however less appropriate for the industrialised populations of the 21st century, because of the switch to more diverse and processed (less abrasive) food.

Most age estimation methods are proven problematic when applied in highly fragmented skeletal remains. Rib histomorphometry is advantageous in such cases; yet it is vital to test and revise existing techniques particularly when used in legal settings (Crowder and Rosella, 2007). This study tested Stout & Paine (1992) and Stout et al. (1994) histological age estimation methods on a Modern Greek sample using different sampling sites. Six left 4th ribs of known age and sex were selected from a modern skeletal collection. Each rib was cut into three equal segments. Two thin sections were acquired from each segment. A total of 36 thin sections were prepared and analysed. Four variables (cortical area, intact and fragmented osteon density and osteon population density) were calculated for each section and age was estimated according to Stout & Paine (1992) and Stout et al. (1994). The results showed that both methods produced a systemic underestimation of the individuals (to a maximum of ...

The review of historic, ethnographic and modern references of dairy husbandry The review of historical, ethnographic and modern dairy systems will provide a reference for the lactation process mechanism for sheep, goats and cattle. This is important to consider particularly for cattle as the presence of a calf to stimulate milk production is a much debated subject (

Проведена оценка возможного влияния миграционного фактора на палеодемографические характеристики выборок русских Нового времени. Материалами для анализа послужили 64 скелетных серии, происходящие преимущественно из раскопок городских кладбищ XVII-XIX вв. Показано, что выборки с территории Сибири отличаются значительно более высоким процентом детей, а также относительно низкой долей индивидов зрелого возраста среди взрослых по сравнению с выборками европейской части России. В целом выявленные различия совпадают с различиями между выборками «первопоселенцев» и «старожилов» независимо от территории проживания. Одна из основных причин специфичности палеодемографической характеристики сибиряков заключается в особенностях половозрастного состава переселенцев и в более высоких темпах прироста населения к востоку от Урала. Обнаружены существенные расхождения в оценках ожидаемой продолжительности жизни, основанных на палеодемографических значениях индекса ювенильности и данных официальной статистики XIX века. Вероятнее всего, они обусловлены расхождениями между возрастными распределениями обитателей сельских и городских поселений, а также недостаточной репрезентативностью скелетных серий. Показано, что в среднем в выборках из военно-административных и промышленных поселений выше доля людей активного трудоспособного возраста, чем в сельских группах. Это объясняется как различиями в половозрастном составе живого населения, так и относительно высокими коэффициентами смертности отдельных возрастных групп, проживавших в поселениях указанных двух типов.

Vault sutures have proven their low reliability for estimating age at death in individual forensic science cases. We broke down the palatine sutures of 134 skulls (with known sex and age at time of death) into 15 subparts and 5 stages of fusion to obtain a mean coefficient of obliteration (Cp) which was then linked to five age classes. We completed this study with multiple regression equations of total palatine suture scores. We compared our results with those obtained using the Mann method on the one hand and classically segmented and scored ectocranial suture age determination methods on the other. Palatine sutures generally do not estimate age at death any better than cranial vault sutures. Despite the partly subjective aspect of suture study, palatine suture observation contributes additional information to age-range estimation, especially in old and very old subjects where other methods lose their effectiveness. ulty

Incremental growth lines in dental enamel are recognized to follow a circaseptan rhythm which is uniform within the dentition of a single individual. Spaced at about eight to ten cross-striations, these ‘striae of Retzius’ are generally considered to be a deviation in the level of mineralization, caused by some process that affected all ameloblasts at the same moment. Even though a circaseptan interval is a recurring feature throughout the biological realm, scholars have not reached consensus on the origins of the regularly appearing lines. The present paper aims at presenting previously suggested causes of the incremental markings, as well as selecting the most promising of these for future research. By elaborating on both functional and causal explanations, a better view on Retzius lines will be acquired. Since the mechanisms behind the interval are poorly understood, most attention will be drawn towards potential causal connections with the interrelation between biorhythms, correlations with body mass, and the interaction with melatonin level fluctuations. Since much of the circaseptan interval can be related to changes in melatonin concentrations, research into the hormonal intervals in humans is expected to yield the most fruitful results. Even though the outcomes of this study are definitely not conclusive, they may provide guidance to the directions for future research that seem to be most promising.

Page 1. Variation in Osteon Circularity and Its Impact on Estimating Age at Death Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Arts in the Graduate School of The Ohio State University By Jesse Roberto Goliath, BA ...

OBJECTIVES The Falys-Prangle-method assesses age-related morphological changes to the sternal clavicle end (SCE), enabling the observation of mature adults from the 5th decade onwards in unburnt human skeletal remains. The aim of this study is to investigate the applicability of the Falys-Prangle-method on burnt human remains. MATERIALS AND METHODS Fifty-two SCE of 40 cremated individuals (out of 86) from the William M. Bass collection of the Forensic Anthropology Center (Knoxville, Tennessee) of known age-at-death and sex are available for assessment. Surface topography, porosity, and osteophyte formation are evaluated, after which the calculated composite score is associated with the corresponding age range as described by Falys and Prangle. The method is also applied on an archaeological case study from Oudenburg, Belgium, dating to the Roman period. RESULTS The assessed age ranges strongly agree with the true age ranges (α = 0.828), suggesting the Falys-Prangle-method to be applicable on burnt human remains. The case study from Oudenburg yields markedly improved age-at-death estimates, significantly enhancing our understanding of the age distribution within this community. DISCUSSION Information on age-at-death is key in the construction of biological profiles of past individuals. The mature adult is often invisible in the archaeological record since most macroscopic age estimation methods do not distinguish beyond 46+ years old. Our study stresses the usefulness of a large-scale application of the Falys-Prangle-method, which will increase the visibility of mature adults, especially in archaeological burnt human skeletal collections, where such information is, at present, extremely difficult to obtain.

Reliable age-at-death estimates from the adult skeleton is of fundamental importance in forensic anthropology, as it contributes to the identity parameters used in a medico-legal death investigation. However, reliable estimates are made difficult by the fact that many traditional aging methods are dependent upon a set of population-specific criteria derived from individuals of European and African descent. The absence of information on the potential differences in the aging patterns of underrepresented, especially Hispanic populations, may hinder our efforts to produce useful age-at-death estimates. In response to these concerns, this study explores the utility of currently available aging techniques, and explores the need, if any, for populationspecific aging method among Hispanic groups. The current study obtained data from two skeletal collections representing modern individuals of Mexican and Puerto Rican origin. Five newly developed computational-shape based techniques utilizing 3D laser scans of the pubic symphysis and one traditional bone-to-phase technique were examined. A validation test of all computational and traditional methods was implemented, and new population-specific equations using the computational algorithms were generated and tested against a sub-sample. Estimated mean ages from the traditional and computational techniques were compared in order to offer practical recommendations for age estimation on cases of Hispanic identity and, in particular, cases presumed to be of Mexican or Puerto Rican individuals. Results from this study suggest that traditional and computational aging techniques applied to the pubic symphysis perform the best with individuals within 35-45 years of age. Levels of bias and inaccuracy increase as chronological age increases, with overestimation of individuals under 35 years of age, and underestimation of individuals over 45 years of age. New regression models provided error rates comparable, and in some occasions, outperformed the original computational models developed Pre-print version. Visit http://digitalcommons.wayne.edu/humbiol/ after publication to acquire the final version. on White American males, but age estimates did not significantly improve. This study has shown that population specific models do not necessarily improve age estimates in Hispanic samples. Results do suggest that computational methods can ultimately outperform the Suchey Brooks method and provide improvement in objectivity when estimating age-at-death in Hispanic samples. Pre-print version. Visit http://digitalcommons.wayne.edu/humbiol/ after publication to acquire the final version. Age-at-death estimation techniques have received considerable attention within the anthropological community, especially among forensic anthropologists, as correctly inferring age-at-death for unknown human remains can aid in making a presumptive identification during the investigative process and can contribute probabilistic evidence towards a positive identification in the medico-legal setting (Algee-Hewitt 2017; Konigsberg et al. 2008; Steadman et al. 2006). Accordingly, age at death is an important component of the biological profile, which also requires the estimation of other such identity parameters as sex, stature, and ancestral background for the skeletonized or fragmentary remains under analysis. However, the estimation of age based on skeletal remains is one of the most challenging biological parameters to estimate. This is in part due to the complex biological variability in aging patterns between and within populations (Kemkes-Grottenthaler 2002), and the methodological and observer-related biases associated with many of the traditional morphological bone-to-phase techniques currently available to the forensic professionals who engage this kind of work across medical-legal fields

"The « probability vectors method » proposed by Claude Masset in 1982 makes it possible to obtain an image of the probable distribution of deaths according to age group in a buried adult population. However, the paleodemographic exploitation of the results is limited to comparisons between funerary sets for which an identical selection criterion is supposed. Indeed, the poor correlation between the osseous indicator and the actual age of the subjects does not allow the individual age of the adults at death to be determined, which would, making certain assumptions, enable the demography of the populations of the past to be reconstructed. Yet, if the breakdown by sex and by age of the population of recruitment of the cemetery is known at the outset, it is possible to estimate, without skew, the age distribution at death of the population buried. Claude Masset has verified this on the basis of examples from historical demography : it was instructive to do it similarly for archaeological populations. The selected sets belong to populations for which the demographic structure is known : nuns of the abbey of Maubuisson, 17th-18th centuries, and inhabitants of Antibes dating from the end of the 19th century. The « probability vectors method » yielded very acceptable results ; however, it should be borne in mind that the vectors provide a probable, and not certain, distribution of deaths."

Age estimation is a critical component of the biological profile in forensic and bioarchaeological contexts.  The majority of age estimation methods are most accurate for individuals of younger age cohorts, typically those under 40 years of age.  Skeletal degeneration can vary greatly between individuals, making age estimation less accurate for adult individuals.  While there are some methods that attempt to age older individuals accurately and precisely, more research must be conducted to expand the range of methods available.  Falys and Prangle (2014) developed a method for estimating age in individuals over the age of 40 using three degenerative characteristics of the sternal end of the clavicle: (1) surface topography, (2) porosity, and (3) osteophyte formation.
In order to test their method, a sample of 1,510 individuals of known sex and age, ranging from 20 to 101 years of age (males: n = 1112, mean = 50.57, SD = 18.015; females: n = 398, mean = 53.065, SD = 20.358), were drawn from the McCormick Collection and the William M. Bass Donated Skeletal Collection at the University of Tennessee.  Due to the paucity of remains of other ancestries, only individuals of reported White ancestry were used in this study.
The two estimation methods proposed in Falys and Prangle (2014), regression equation and composite score, were tested to see how well they perform when applied to a different sample population than the populations used to develop the method.  When applied to the collected data, the regression equation produced age estimations that fell within the 95% confidence interval in 47.6% of the male sample and 57.4% of the female sample.  Composite scores were calculated and compared to the corresponding age ranges provided in Falys and Prangle (2014).  The composite scores of the male sample estimated the age of an individual more accurately than the composite scores of the female sample (male = 65.9%; female = 58.8%).  The lowest estimation accuracy for both males and females was between 70-79 years of age (male = 46.0%; female = 51.4%).  From 80-89 years of age, the accuracy increased for males (76.4%) and females (69.4%).
The sample also included individuals under the age of 40 in order to test whether the inclusion of clavicles with recent epiphyseal union would affect the applicability of the Falys and Prangle (2014) method.  Multiple regression equations were generated: (1) individuals over 20 years of age, (2) individuals over 30 years of age, and (3) individuals over 40 years of age.  The results from the multiple regression analyses show comparable Pearson’s coefficients for the above mentioned equations (r = 0.690, r = 0.632, and r = 0.611, respectively). 
Spearman’s rank correlation coefficients indicated a correlation significant at the 0.01 level for all three components individually, as well as the composite score.  Of the three components, surface topography was most strongly correlated with age for both males (r = 0.643) and females (r = 0.590).  Unlike the findings of Falys and Prangle (2014), porosity was found to be the least correlated with age for both males (r = 0.474) and females (r = 0.514).  In addition, when broken down into ten year intervals (40-49, 50-59, etc.), the correlation coefficients increase with advancing age.  This suggests that the method becomes more accurate as the age of an individual increases.
The inter-observer and intra-observer agreement tests produced very low agreement values.  The low observer agreement indicates that the current scoring method is not a reliable, repeatable technique. However, when examined further, the observed trait values that differed between the tests primarily differed by one score. These results suggest that condensing the scores in order to account for more variation would likely increase the observer agreement. However, condensing the scores would result in larger age intervals, which nullifies the purpose of this method.
The findings in the present study indicate that the sternal end of the clavicle has potential for use in age estimation in older individuals.  Although the present study produced lower correlation coefficients than proposed by the original study in 2014, the correlations and age-at-transition test results suggest that the sternal end of the clavicle deteriorates in a predictable manner that, with more observation and understanding, could be used to accurately age older individuals more precisely than the large age intervals currently in use.  Despite the correlations between the degeneration of the sternal end of the clavicle and the age-at-death, the error rates suggest it is not a reliable alternative to the current methods used.