Evaluation of the Suchey-Brooks method for aging skeletons in the Balkans

Skeletal age-at-death estimation: validating the Suchey-Brooks method using 3D reconstructed models in a contemporary Indonesian population

The Suchey-Brooks (S-B) standard is one of the most frequently applied approaches for age-at-death estimation in modern forensic practice. However, classification accuracy is known to vary across different populations. At present, there is a paucity of research related to the assessment of biological attributes in Indonesia, particularly the estimation of age-at-death. The use of computed tomography (CT) in S-B phase assignments has been validated in the literature. In considering further validating the use of CT, transition analysis (TA), and Bayesian statistics in age-at-death estimation, this study evaluated the accuracy of the S-B standard on a sample obtained from Indonesia. TA and Bayesian statistics are incorporated to address methodological issues such as age mimicry. A total of 378 multi-slice CT scans were analysed in OsiriX®. TA and Bayesian statistics were used to derive age-at-death estimation models. Overall bias values were at - 6.0 years for females and - 13.1 years for males, while inaccuracy was at 9.6 years for females and 14.6 years for males. When applying the original S-B age ranges, 92.0% of females and 73.3% of males were correctly classified. Likewise, mean ages per S-B phase were higher in the Indonesian sample, except for females assigned to Phase VI. TA and Bayesian statistics derived age-at-death distribution models specific to the Indonesian population. The dissemination of an appropriate age-at-death estimation standard in the literature is of considerable benefit to casework conducted domestically in Indonesia, and also serves to further inform aspects of general forensic practice globally.

The Effect of Cancer and Cancer Treatment on Pubic Symphysis Age Estimation Using Computed Tomography Scans

It is currently unknown whether cancer and cancer treatment affect age-related skeletal changes used in the biological profile for skeletonized remains. This research examines the effects of cancer on skeletal age estimation using computed tomography (CT) scans of the pubic symphyses for 307 individuals from the New Mexico Descendent Image Database. The Suchey-Brooks method was applied to 125 individuals without documented cancer and 182 individuals with documented cancer. Individuals were correctly aged if their chronological age fell within the original study's 95% prediction range. Though not statistically significant, the results show that females with cancer were aged correctly 74.7% of the time, and females without cancer were aged correctly 85.1% of the time; males with cancer were aged correctly 46.0% of the time, and males without cancer were aged correctly 55.7% of the time. Additionally, a total of 30 individuals were reanalyzed to examine intraobserver error, and a Cohen's kappa value of k = 0.600 indicated a moderate level of agreement. While no statistical differences were found between cancer and control groups, CT scans may lack the resolution needed to visualize the nuanced effects of bone mineral density loss, if present, and the overall quality of bone, despite their proven utility in dry-bone skeletal analyses.

Applicability of the Suchey-Brooks method for age estimation in an Indian population: A computed tomography-based exploration using Bayesian analysis and machine learning

Age estimation occupies a prominent niche in the identification process. In cases where skeletal remains present for examination, age is often estimated from markers distributed throughout the skeletal framework. Within the pelvis, the pubic symphysis constitutes one of the more commonly utilized skeletal markers for age estimation, with the Suchey-Brooks method comprising one of the more commonly employed methods for pubic symphyseal age estimation. The present study was targeted towards assessing the applicability of the Suchey-Brooks method for pubic symphyseal age estimation, an aspect largely unreported for an Indian population. In order to do so, clinically undertaken pelvic computed tomography scans of individuals were evaluated using the Suchey-Brooks method, and the error associated with the method was established using Bayesian analysis and different machine learning regression models. Amongst different supervised machine learning models, support vector regression and random forest furnished lowest error computations in both sexes. Using both Bayesian analysis and machine learning, lower error computations were observed in females, suggesting that the method demonstrates greater applicability for this sex. Inaccuracy and root mean square error obtained with Bayesian analysis and machine learning illustrates that both statistical modalities furnish comparable error computations for pubic symphyseal age estimation using the Suchey-Brooks method. However, given the numerous advantages associated with machine learning, it is recommended to use the same within medicolegal settings. Error computations obtained with the Suchey-Brooks method, regardless of the statistical modality utilized, indicate that the method should be used in amalgamation with additional markers to garner accurate estimates of age.

Technical note: Interest of focused fields in post-mortem computed tomography using photorealistic images for age at death estimation from the pubic symphysis

INTRODUCTION

The morphological assessment of the pubic symphysis using the Suchey-Brooks method is considered a reliable age at death indicator. Age at death estimation methods can be adapted to the images obtained from post-mortem computed tomography (PMCT). The aim of this study is to evaluate the utility of pubic symphysis photorealistic images obtained through Global illumination rendering (GIR) for age at death estimation from whole-body PMCT and from focused PMCT on the pubic bone.

MATERIALS AND METHODS

We performed virtual age at death estimation using the Suchey Brooks method from both the whole-body field of view (Large Field of View: LFOV) and the pubis-focused field of view (Small and Field of View: SFOV) of 100 PMCT. The 3D photorealistic images were evaluated by three forensic anthropologists and the results were statistically evaluated for accuracy of the two applied PMCT methods and the intra- and inter-observer errors.

RESULTS

When comparing the two acquisitions of PMCT, the accuracy rate reaches 98.5% when using a pubic-focused window (SFOV) compared to 86% with a whole-body window (LFOV). Additionally, the intra- and inter-observer variability has demonstrated that the focused window provides better repeatability and reproducibility.

CONCLUSION

Adding a pubic-focused field of view to standard PMCT and processing it with GIR appears to be an applicable technique that increases the accuracy rate for age at death estimation from the pubic symphysis.

Age-at-death estimation based on micro-CT assessment of pubic symphysis: Potentially new methodological approach

BACKGROUND

Although various methods for age-at-death estimation of skeletal remains are available, this is still an unsolved issue in forensic anthropology, especially concerning elderly individuals. Moreover, the lack of population-specific methods often made age-at-death estimation unreliable in other populations.

AIM

Our study aimed to examine whether micro-computed tomography (micro-CT) analysis of pubic bone samples obtained from the contemporary Serbian population could be used in anthropological and forensic practice for age-at-death estimation.

METHODOLOGY

This study encompassed 62 pubic samples obtained from 26 adult male and 36 adult female cadaveric donors (age range: 22-91 years). Initially, staging according to the Suchey-Brooks phases was performed by two experienced investigators, followed by micro-CT assessment of pubic bone trabecular and cortical compartments (spatial resolution of the scans was 10 µm).

RESULTS

Our results revealed an age-associated decline in trabecular and cortical micro-architecture of elderly male and female individuals, with the most prominent changes present in trabecular bone volume fraction and total porosity of the anterior and posterior cortical surface of the pubic bone. Those parameters were used to generate age-at-death estimation equations. One sample t-test did not reveal a significant difference between estimated age-at-death and real (known) age-at-death in the overall sample (mean absolute error [MAE] of 4.76 years), female (MAE of 9.66 years) and male cadaveric donors (MAE of 6.10 years, p > 0.05).

CONCLUSION

Our data indicated that micro-architectural features of trabecular and cortical compartments of pubic bone could potentially be applied as an additional reliable method for age-at-death estimation in the Serbian population.

Age estimation by modified Suchey-Brooks method using three-dimensional reconstructed CT images of Chinese Han population

The method proposed by Suchey-Brooks for adult age estimation based on the surface morphology of the pubic symphysis has been widely accepted. The applicability of the method varies considerably in different populations. The present study established a virtual reference sample and aimed to develop population-specific criteria that can be used for age estimation in different skeletal samples. First, The dry bone specimens from 100 individuals were compared with their corresponding three-dimensional (3D) reconstruction model and showed high inter-method agreement (k = 0.743-0.811), suggesting that the virtual bone model and physical bone specimens have comparable performances in describing the surface morphology of the pubic symphysis. We retrospectively collected clinical computed tomography (CT) data from 895 Chinese patients to create a virtual reference sample of the pubic symphysis. Based on the original Suchey-Brooks method, each of the 895 reference samples was assigned a phase, for each sex and phase, data on the mean age, standard deviation, and 95% age range of the corresponding sample were obtained, which was then used as the "method modified for Chinese" (modified method) and compared to the "SB method". Compared to the SB method, modified method had a lower inaccuracy in dry bones for males over 35 years and females over 45 years, in dry bone CT test sample for males over 55 years and females over 45 years, and in postmortem CT test sample for males over 35 years and females over 55 years. The modified method can improve the accuracy of age estimation for older samples over 40 years. It has shown considerable reliability when applied as a population-specific criterion, but its accuracy is still not sufficient, and caution is needed when using it.

Identification of Skeletal Remains Using Genetic Profiling: A Case Linking Italy and Poland

Forensic genetics is a rapidly evolving science thanks to the growing variety of genetic markers, the establishment of faster, less error-prone sequencing technologies, and the engineering of bioinformatics models, methods, and structures. In the early 2000s, the need emerged to create an international genetic database for forensic purposes. This paper describes a judicial investigation of skeletal remains to identify the subject using various methods. The anthropological examination of the remains allowed identification of the Caucasoid (European) ethnic group, a height of 156 ± 4 cm, and an age between 47 and 50 years. The genetic profiles obtained from typing several microsatellites made it possible to evaluate the compatibility between the skeletal remains and the suspected decedent. To identify the remains, the two extrapolated genetic profiles were compared. The case described highlights the central role of forensic genetics in identifying skeleton remains by means of comparison.

Forensic human identification: retrospective investigation of anthropological assessments in the Western Cape, South Africa

The identification of unknown persons, particularly those who are decomposed or burnt, is a global challenge. Forensic Anthropology Cape Town (FACT) is a service provider that assists the South African state with the identification of human remains. However, empirical data pertaining to anthropologically analysed forensic cases in the Western Cape Province of South Africa are lacking. Therefore, anthropological data pertaining to the forensic cases submitted to FACT between 2006 and 2018 from Forensic Pathology Services were retrospectively reviewed (n = 172). This study also sought to assess demographic, traumatic and pathological factors that impacted successful identification. Most decedents were male (67%) and older than 35 years (54%). While ante-mortem trauma was observed in 41% of decedents, the lack of medical records on ante-mortem injuries hindered the use of this information for identification. Positive identifications were reached for 37% of decedents, and of these, anthropological estimations were correct in 98% of cases for sex, 84% of cases for age at death and 100% of cases for stature. Considering globally accepted accuracies of 70-80%, these estimations were considered highly accurate, suggesting the anthropological methods used are suited to the population. However, 63% of cases remained unidentified, and this study showed that skeletal completeness and pathological conditions were the main factors that hindered demographic estimations. Lastly, not all unidentified bodies in the province were referred to FACT; given the highly accurate estimations, these data advocate for the routine, if not mandatory, use of forensic anthropology services for skeletonised remains in South Africa, with the overall purpose of positively impacting human identification. To improve identification rates globally, these data highlight the value of retrospective and region-specific studies to identify strengths and weaknesses in the system.

Validation of a post-mortem computed tomography method for age estimation based on the 4th rib in a French population

Age estimation is a key factor for identification procedure in forensic context. Based on anthropological findings, degenerative changes of the sternal extremity of the 4th rib are currently used for age estimation. These have been adapted to post-mortem computed tomography (PMCT). The aim of this study was to validate a post-mortem computed tomography method based on a revision of the Iscan's method on a French sample. A total of 250 PMCT (aged from 18-98 years (IQR 36-68 years, median 51 years); 68 (27%) females) from the Medicolegal Institute of Paris (MLIP) were analyzed by two radiologists. The sternal extremity of 4th right rib was scored using method adapted from Iscan et al. Weighted κ was used to evaluate intra- and inter-observer reliability and Spearman correlation was performed to evaluate relationship between age and score. Confidence intervals for individual prediction of age based on 4th rib score and sex were computed with bootstrapping. The intra-observer reliability and inter-observer reliability were almost perfect (weighted κ = 0.85 [95%CI: 0.78-0.93] and 0.82 [95%CI 0.70-0.96] respectively). We confirmed a high correlation between the 4th rib score and subject age (rho = 0.72, p < 0.001), although the confidence intervals for individual age prediction were large, spanning over several decades. This study confirms the high reliability of Iscan method applied to PMCT for age estimation, although future multimodal age prediction techniques may help reducing the span of confidence intervals for individual age estimation.Trial registration: INDS 0,509,211,020, October 2020, retrospectively registered.

The accuracy and reliability of the Suchey-Brooks pubic symphysis age estimation method: Systematic review and meta-analysis

Suchey-Brooks method has been studied many times with varying reports of accuracy and reliability. A systematic review and meta-analyses were utilized to quantitatively determine the accuracy and reliability of the Suchey-Brooks (S-B) method. A systematic search of PubMed and EBSCO health and medical databases was performed. Meta-analyses were performed to quantify the relationship between actual known age at death and the S-B method using Spearman's Rho and Pearson's r for (1) combined males and females estimates, (2) male-only estimates, and (3) female-only estimates. Overall correlation coefficient using Cohen's kappa, Spearman's Rho, and Pearson's r was also calculated to determine the interrater and intrarater reliability using the S-B method. Eighteen studies classified as moderate-to-high methodological quality met the inclusion criteria. The sample sizes were different for the combined male and female (n = 2620), male-only (n = 2602), and female-only (n = 1431) meta-analyses. The effect size of the age at death meta-analyses was large and significant for combined males and females (Spearman's Rho = 0.62; Pearson's r = 0.65), male-only (Spearman's Rho = 0.77; Pearson's r = 0.75), and female-only (Spearman's Rho = 0.71; Pearson's r = 0.71). The overall correlation coefficients of the interrater (Kappa = 0.76; Spearman's Rho = 0.73; Pearson's r = 0.80) and intrarater (Kappa = 0.81; Spearman's Rho = 0.91; Pearson's r = 0.83) reliability meta-analyses were large and significant. A significant degree of heterogeneity was present in all meta-analyses, with minimal evidence of publication bias. The meta-analyses results suggest the S-B method is highly reliable with a moderate-to-high degree of accuracy. Our results also identified sample size and accuracy differences between male and female individuals.

Computed tomographic age estimation from the pubic symphysis using the Suchey-Brooks method: A Systematic Review and Meta-analysis

Forensic age estimation is routinely applied in investigations involving identification of individuals. Over the past century a myriad of methods have been devised for age estimation. One such method, proposed by Suchey and Brooks in 1990, groups the observed changes occurring in the pubic symphysis into six phases, each defined by a corresponding age range. The present study was piloted with the focussed question being to empirically determine the accuracy of the Suchey-Brooks method in computed tomographic age estimation by analysing morphological changes occurring in the pubic symphysis. Original articles pertaining to the use of the Suchey-Brooks method for CT based age estimation were extracted from four different databases- PubMed, CENTRAL, Google Scholar and ScienceDirect. Research papers which were answering the focussed question were selected for data analysis. After assessing the risk of bias of the selected articles, the data was subjected to Meta-analysis. Pooled analysis of correctly/accurately aged individuals/remains using the random and fixed effect models yielded a prediction percentage of 78% and 86%, respectively. Higher percentages were obtained for phase-wise and subgroup analysis, indicating that the Suchey-Brooks method is a reliable method for age estimation.

Application and analysis of the Rissech acetabular adult aging method in a Colombian sample

The classical age indicators of the innominate have been the pubic symphysis and auricular surface. However, recently, the acetabulum has been highlighted as an indicator of adult age, with applicability in young, middle-aged, and older adults. The Rissech acetabular method was developed in a Portuguese population and tested in European and European-Americans, giving estimates within 10 years of age in more than 89% of the sample. The main goal of this paper is to test the Rissech acetabular method in a modern South American sample. The material used for the study was 184 women and 378 men from a Colombian-documented skeletal collection. The obtained morphological scores from the acetabulum were analyzed through the IDADE2 web page, a Bayesian statistical program that estimates a relative likelihood distribution for the target individuals, produces age estimates, and provides 95% confidence intervals. Results showed this method is useful in the modern Colombian population with an average absolute error of 10.63 years in females and 9.44 years in males. These errors are similar to those obtained in other European and North American samples when this method was performed and similar or lower than those obtained when the 3 classical aging methods (Suchey-Brooks, Buckberry-Chamberlain, and Lovejoy) were applied in the same collection (absolute error: 10.29 years ♀ and 9.05 years ♂ in Suchey-Brooks, 12.5 years ♀, and 12.17 years ♀ in Buckberry-Chamberlain, and 13.54 years ♀ and 10.99 years ♂ in Lovejoy). Although Rissech's method was developed in a Western European sample, the results of this study indicate its applicability in modern Colombian samples with reasonable accuracy.

Applicability of pulp/tooth ratio method for age estimation

The purpose of this study was to evaluate the reliability of the tooth/pulp ratio method in the process of age estimation at the moment of death in a forensic context and compare it with standard anthropological methods. After the exhumation of mass graves located in sites in Batajnica, Serbia, in 2002 and 2003, skeletal material was thoroughly analyzed by a group of anthropologists and pathologists. As a part of the investigation, orthopantomography (OPG) was performed for each individual. During 2018 these OPGs were reexamined for scientific purposes. Age-at-death was assessed by means of the pulp/tooth ratio method applied to all available lower premolars. Estimated age following standard anthropological methods and chronological age (obtained after DNA identification of victims) was taken from the records. Age estimation using the pulp/tooth ratio and standard methods was compared with chronological age. The pulp/tooth ratio method was accurate in 81.25% of all cases and the standard method was accurate in 56.25% of all cases. The pulp/tooth ratio method of age estimation was found to be applicable and accurate. However, age estimation should be based on all available methods.

Evaluation of the Enhanced Computational Methods of Estimating Age-at-Death Using the Pubic Symphyses of a White South African Population

To address problems of reproducibility related to current age estimation methods, the enhanced computational Methods (ECM) were previously developed using a sample of white North American male pubic symphyses and showed promise in improving current techniques. However, given the evidence of sex and population differences in the onset of age markers, this study set out to test the ECM on a white South African sample. The sample consisted of 184 well-preserved os coxae from individuals of known age and sex. Pubic symphyseal surfaces were scanned using the Artec Spider 3D scanner, processed using Artec Studio 10 and analyzed using forAge. Point estimates of age were then compared to the true age of each individual. Results indicate that the ECM performed poorly in a white South African population, with consistent underestimation of age-at-death and weak positive correlations with true age. Despite the low correlations, the ECM did, however, reduce observer error.

Reconsidering osteoarthritis as a skeletal indicator of age at death

OBJECTIVES

Osteoarthritis (OA) generally increases with age, but it is a complex, multifactorial disease. This study investigated whether obesity, physical activity, and antemortem trauma preclude the use of OA for skeletal age estimation.

MATERIALS AND METHODS

The temporomandibular joint (TMJ) and all appendicular joints were scored for skeletal indicators of OA in 408 modern European-Americans (Bass Collection, TN). Binomial generalized linear models (GLMs) assessed the contributions of self-reported demographic data to OA, including: age; body mass index (BMI); and metabolic values for physical activities. Repeated resampling tested whether observed mean OA scores for joints with trauma consistently exceeded mean scores for unaffected joints. Single-variable GLM probit models were generated for OA presence/absence data in relevant joints.

RESULTS

Age was the only statistically significant predictor of OA in most multivariable GLMs. Occupation and age were both significant predictors of male hand OA; BMI was the only significant predictor of female ankle OA. Trauma significantly affected OA in most joints. Age cut-offs calculated from the single-variable probit models (representing ages of transition to "OA present") ranged from 29.7 to 77.3 years (90%) and 32.7 to 96.6 years (95%), but were problematic for the male TMJ.

DISCUSSION

Ankle OA should not be used to age females; TMJ OA should not be used to age males. For other joints, using OA to inform age estimates appears valid (in absence of antemortem trauma). While skeletal evidence of OA is not a primary age indicator, its presence can refine age ranges and provide essential age data in fragmentary cases.

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

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

Validation of the Acetabulum As a Skeletal Indicator of Age at Death in Modern European-Americans

Progressive changes in the acetabulum have been used in modern skeletal age estimation, but they have not been completely understood. If their age correlations are weakened by the influence of factors like physical activity and obesity, acetabular changes should not be used for age estimation. To investigate their utility for aging, the acetabular variables of Rissech et al. (2006) were analyzed in 409 modern European-Americans (Bass Collection, Tennessee). Correlation tests assessed potential associations between acetabular data, osteoarthritis scores (collected per Jurmain, 1990), and documented demographic information (age, body mass index [BMI], metabolic intensity of physical activities). Acetabular changes had statistically significant, positive correlations with osteoarthritis (p < 0.001 in most joints/regions) and age (p < 0.001), indicating their degenerative nature and relevance for age estimation. Acetabular changes showed no associations with BMI or metabolic values, suggesting resistance to obesity and activity effects. These results suggest that acetabular degeneration is a valid skeletal age-at-death indicator.

A Study on the Asymmetry of the Human Left and Right Pubic Symphyseal Surfaces Using High-Definition Data Capture and Computational Shape Methods

The pubic symphysis is among the most commonly used bilateral age indicators. Because of potential differences between right and left sides, it is necessary to investigate within-individual asymmetry, which can inflate age estimation error. This study uses 3D laser scans of paired pubic symphyses for 88 documented White males. Scan data are analyzed by numerical shape algorithms, proposed as an alternative to traditional visual assessment techniques. Results are used to quantify the within-individual asymmetry, evaluating if one side produces a better age-estimate. Relationships between the asymmetry and advanced age, weight, and stature are examined. This analysis indicates that the computational, shape-based techniques are robust to asymmetry (>80% of paired differences are within 10 years and >90% are within 15 years). For notably more asymmetric cases, differences in estimates are not associated with life history factors. Based on this study, either side can be used for age-at-death estimation by the computational methods.

A test of four innominate bone age assessment methods in a modern skeletal collection from Medellin, Colombia

Studying bone collections with known data has proven to be useful in assessing reliability and accuracy of biological profile reconstruction methods used in Forensic Anthropology. Thus, it is necessary to calibrate these methods to clarify issues such as population variability and accuracy of estimations for the elderly. This work considers observations of morphological features examined by four innominate bone age assessment methods: (1) Suchey-Brooks Pubic Symphysis, (2) Lovejoy Iliac Auricular Surface, (3) Buckberry and Chamberlain Iliac Auricular Surface, and (4) Rouge-Maillart Iliac Auricular Surface and Acetabulum. This study conducted a blind test of a sample of 277 individuals from two contemporary skeletal collections from Universal and San Pedro cemeteries in Medellin, for which known pre-mortem data support the statistical analysis of results obtained using the four age assessment methods. Results from every method show tendency to increase bias and inaccuracy in relation to age, but Buckberry-Chamberlain and Rougé-Maillart's methods are the most precise for this particular Colombian population, where Buckberry-Chamberlain's is the best for analysis of older individuals.

Inaccuracy and bias in adult skeletal age estimation: Assessing the reliability of eight methods on individuals of varying body sizes

Accurate age estimations are essential for identifying human skeletal remains and narrowing missing persons searches. This study examines how BMI, body mass, and stature influence inaccuracy and bias in adult skeletal age estimations obtained using eight methods. 746 skeletons from the Hamann-Todd and William Bass Collections were used. Underweight BMI, light body mass, and short-stature individuals have the most error associated with their age estimates and are consistently under-aged between 3 to 13years. Obese BMI, heavy body mass, and tall-stature individuals are consistently over-aged between 3 to 8.5years. The most reliable methods for smaller-bodied individuals are Kunos et al. (first rib) and Buckberry-Chamberlain (auricular surface); for individuals in the average range, İşcan et al. (fourth ribs) and Passalacqua (sacrum); and for larger-bodied individuals, İşcan et al., Passalacqua, and Rougé-Maillart et al. (auricular surface and acetabulum). Lovejoy et al. (auricular surface) and Suchey-Brooks (pubic symphysis) produce consistent inaccuracy and bias scores across all body size groups. The least reliable method for smaller-bodied individuals is İşcan et al.; for larger-bodied individuals, Buckberry-Chamberlain; and across all body size groups, DiGangi et al. (first rib).

New approach to age estimation of male and female adult skeletons based on the morphological characteristics of the acetabulum

Age estimation is essential to the human identification process, both in forensic and archeological contexts. Based on the previous male-specific method of Rissech et al. (J Forensic Sci, 2006, 51:213-229), a new approach to age estimation based on the acetabulum has been described and evaluated in 611 individuals from the Lisbon Collection (Lisbon, Portugal). This paper has two main goals: (1) to revise and better define the variables of Rissech's method related to the acetabular fossa, namely, variables 5, 6, and 7, and (2) to extend the applicability of this new approach to both sexes while analyzing age-related sex differences in the acetabular aging process. The results demonstrate the suitability of combining acetabulum traits and a Bayesian approach to estimating age in adults of both sexes. This study has confirmed the usefulness of the redefined variables of the acetabular fossa when age-related changes are considered. Furthermore, the newly defined variables have good to excellent values of repeatability. The study has also extended the method's applicability to females. The revised method has absolute error averages of 7.28 years for males and 7.09 years for females, based on a sex-specific reference sample. In addition, approximately 74 % of the individuals estimated had an absolute error less than 10 years. Interestingly, the acetabular aging process follows similar trends in both sexes, but the aging rate seems to be different between males and females, especially in middle-aged individuals. Despite the fact that the age estimates, on average, did not improve significantly with the use of a sex-specific reference sample, it is recommended that the sexes be analyzed separately due to the differences in aging rates and inaccuracy values.

Modeling Bone Surface Morphology: A Fully Quantitative Method for Age-at-Death Estimation Using the Pubic Symphysis

The pubic symphysis is widely used in age estimation for the adult skeleton. Standard practice requires the visual comparison of surface morphology against criteria representing predefined phases and the estimation of case-specific age from an age range associated with the chosen phase. Known problems of method and observer error necessitate alternative tools to quantify age-related change in pubic morphology. This paper presents an objective, fully quantitative method for estimating age-at-death from the skeleton, which exploits a variance-based score of surface complexity computed from vertices obtained from a scanner sampling the pubic symphysis. For laser scans from 41 modern American male skeletons, this method produces results that are significantly associated with known age-at-death (RMSE = 17.15 years). Chronological age is predicted, therefore, equally well, if not, better, with this robust, objective, and fully quantitative method than with prevailing phase-aging systems. This method contributes to forensic casework by responding to medico-legal expectations for evidence standards.

Technical note: The two step procedure (TSP) for the determination of age at death of adult human remains in forensic cases

This paper presents the principles and results of TSP (the two step procedure), a comprehensive (combined) method of age estimation in mature human skeletal remains. The first step consists of the examination of the pubic symphysis using the Suchey-Brooks system for a "pre-choice". Then for SBS phases I, II, III, (young adults up to about 40) the age estimate is given using the chronological interval corresponding to each phase. For SBS phase is IV, V or VI (mature adults, about 40 to 60), then (second step) the dental method of Lamendin (using single rooted tooth) will be applied alone. Both methods are fast, easy to learn and to use (requiring no preparation except cleaning soft tissues from the pubic bone) and are not expensive, making TSP usable by all pathologists or anthropologists in any Forensic unit. It is also of great practical use in mass disaster and mass grave situation. After 15 years of use, a literature review and four evaluation studies we confirm that TSP is more accurate than any single method for aging adults and at least as good as more complicated combined methods. Despite its advantages TSP is, like all other aging methods, not efficient in adults over 65 years of age.

Skeletal age estimation based on medial clavicle--a test of the method reliability

In order to establish a reliable age indicator in the period when all other epiphyseal age indicators have already been inactivated, medial clavicle as the bone with the longest period of growth became the object of various investigations. However, the lack of population-specific method often made it unreliable in some regions. The current study involved a Balkan population and it was designed in order to examine whether morphological, radiological, and histological analyses of medial clavicles could be applied with success in age assessment of individuals beyond their twenties in anthropological and forensic practice. The medial clavicular specimens were collected from contemporary Serbian population, autopsied in the period from 1998 to 2001, encompassing 67 individuals (42 males and 25 females) with the age range from 20 to 90 years. The conducted analyses of morphological features identified the epiphyseal union timing, signs of lipping in the region of the notch for the first rib as well as exostoses and bone overgrowths of the articular surface margin as age-dependent attributes. Trabecular bone volume fraction and minimum trabecular width were also highlighted as age-distinctive microscopic features. Sex difference was ascertainable in epiphyseal union timing, morphology of the notch for the first rib, margin of the articular surface, and basic morphology of articular surface as well as in two microscopic characteristics: trabecular bone volume fraction and minimum trabecular width. The study managed to identify several age- and sex-related features that could be applied as additional guidance for age estimation in Serbian population.

Morphological characteristics of pubic symphysis for age estimation of exhumed persons

Suchey-Brooks method based on morphological features of pubic symphysis is a common method of age evaluation of human skeletal remains. The aim of the study was the classification of the examined samples into a particular phase according to Suchey-Brooks method, comparing the estimated age according to Suchey-Brooks with living age of the identified persons. The study was conducted on 120 pairs of pubic bones symphysis of male who disappeared from the area of north-west Bosnia during previous war, who were exhumed and the process of their identification was previously finished. The youngest person was 19 years old and the oldest 86. The study was retrospective, made by comparing the morphological characteristics of pubic symphysis pairs of the examined sample with Suchey-Brooks standards. The statistical analysis of data obtained by the survey showed that the smallest deviations from the average were in phase II by Suchey-Brooks, while the maximum deviation was in phase IV. The standard deviation generally increases from phase to phase, which is to be expected. The span of age obtained for Bosnian population is smaller at all stages in relation to Suchey Brooks-standards, as well as standard deviation, except in phases IV and VI. There was a significant difference noticed in phase V in the estimation of age between the original method and Bosnian population. In general, Suchey-Brooks method leads to underestimation of age, but the underestimation or overestimation in relation to the actual age is possible at each stage, which indicates the individual biological variation.

Transition analysis: a validation study with known-age modern American skeletons

Transition Analysis-a recent skeletal age-estimation procedure (Boldsen et al.: Paleodemography: age distributions from skeletal samples (2002) 73-106)-is evaluated using 252 known-age modern American males and females from the Bass Donated Collection and Mercyhurst forensic cases. The pubic symphysis worked best for estimating age, followed by the sacroiliac joint and cranial sutures. Estimates based on all skeletal characteristics are influenced by the choice of prior distribution, although its effect is dwarfed by both the inaccuracy and imprecision of age estimates. Age intervals are narrowest for young adults, but are surprisingly short in old age as well. When using an informative prior distribution, the greatest uncertainty occurs from the late 40s into the 70s. Transition Analysis estimates do not perform as well as experience-based assessments, indicating the existing procedure is too narrowly focused on commonly used pelvic and cranial structures.

Gradients of occlusal wear in hunter-gatherers and agriculturalists

Occlusal wear was recorded in maxillary teeth from three North American late Archaic (3385 +/- 365 cal BC) hunter-gatherer sites (n = 306) and late Anasazi-early Zuni agricultural sites ( approximately 1300 AD) (n = 87). Comparisons were undertaken using descriptive and inferential statistics to determine differences between these groups, and along the maxillary tooth row. The hunter-gatherers had a significantly greater percentage of occlusal wear than the agriculturalists. For both hunter-gatherers and agriculturalists, occlusal wear was greatest on the central incisors and first molars. The third molars had the least amount of wear. It was inferred from these results that the hunter-gatherers had a more abrasive diet, and different daily task activities compared to the agriculturalists. One further finding was that wear patterns on anterior and posterior teeth are influenced by the order that teeth erupt into the jaw, as well as diet and behavior.

Age determination from central incisors of fetuses and infants

Age at time of death for a fetus or infant is an important issue in the field of forensic science. Dental development can give an accurate measure of infant and fetal age and current literature does not include any studies of dental age from central incisor development. The objective of this study is to determine the age of deceased fetuses and infants by examining metric tooth development of central incisors in deceased fetuses and infants. Five dimensions of 76 maxillary and mandibular central incisors were measured: mesio-distal (MD), bucco-lingual (BL), crown height (CH), crown thickness (CT), and root height (RH). The results showed that 44.45+/-0-2 weeks is a sectional time for age calculations, which corresponds to 40 weeks from conception plus 4 to 5 weeks after birth. Four ATA entitled age formulas are derived to give the relation of age with tooth dimensions before and after 44.45 weeks [ATA is the special name given to the honor of the great Turkish leader Mustafa Kemal Atatürk (1881-1938)]. Age estimation can be calculated from these formulas with an accuracy of the age +/-0-2 weeks. Also, calcification time can be determined from ATA formulas. In conclusion, the age of fetuses and infants can be assessed by the measurements of a single central incisor. According to this research, when estimating age during identification studies, forensic researchers must take into consideration the period of embryonic human growth and development.