OBJECTIVES: Adult age at death estimation continues to challenge physical anthropologists. One estimation method involves counting tooth cementum annulations (TCA). Non-destructively accessing TCA is a critical step to approaching fossil teeth of unknown age and to verifying life history profiles of human ancestors. This pilot study aims to (a) non-destructively image TCA in teeth from a known age archeological human population by propagation phase contrast X-ray synchrotron μCT (PPC-SR-μCT) (b) test the correlation between real and estimated ages, and the accuracy, precision and bias of age estimates. MATERIALS AND METHODS: We examine 20 permanent human canines (aged 20-81 years), from a 18th to 19th century known age collection from St. Luke's Church (London, England). We scanned transverse segments of acellular cementum in the apical portion of the middle root third using PPC-SR-μCT. We generated virtual transverse sections on which two observers perform two sessions of blind TCA counts. We calculate the estimated ages at death by adding 10 years to the TCA counts. RESULTS: A moderately strong positive linear relationship exists between real and estimated ages (r = 0.76, p 50 years (24.9 years, n = 10). DISCUSSION: We reliably imaged and identified TCA in individuals <50 years from a known-age archeological sample. Scanning refinement will yield a promising alternative to current destructive methods of TCA analyses and to aid access to life history events in adult fossil hominins.

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Nondestructive adult age at death estimation: Visualizing cementum annulations in a known age historical human assemblage using synchrotron X-ray microtomography.

Data Collection Codebook

Despite the prominent use of the pubic symphysis for age estimation in forensic anthropology, little has been documented regarding the quantitative morphological and micro-architectural changes of this surface Specifically, utilising post-mortem computed tomography data from a large, contemporary Australian adult population, this study aimed to evaluate sexual dimorphism in the morphology and
bone composition of the symphyseal surface; and temporal characterisation of the pubic symphysis in individuals of advancing age

The sample consisted of multi-slice computed tomography (MSCT) scans of the pubic symphysis(slice thickness: 05 mm, overlap: 01 mm) of 200 individuals of Caucasian ancestry aged 15–70 years, obtained in 2011 Surface rendering reconstruction of the symphyseal surface was conducted in OsiriX1 (v41) and quantitative analyses in Rapidform XOSTM and OsteomeasureTM Morphometric variables
including inter-pubic distance, surface area, circumference, maximum height and width of the symphyseal surface and micro-architectural assessment of cortical and trabecular bone compositions were quantified using novel automated engineering software capabilities

The major results of this study are correlated with the macroscopic ossification and degeneration pattern of the symphyseal surface, demonstrating significant age-related changes in the morphometric and bone tissue variables between 15 and 70 years Regardless of sex, the overall dimensions of the symphyseal surface increased with age, coupled with a decrease in bone mass in the trabecular and
cortical bone compartments Significant differences between the ventral, dorsal and medial cortical surfaces were observed, which may be correlated to bone formation activity dependent on muscle activity and ligamentous attachments Our study demonstrates significant sexual dimorphism at this site, with males exhibiting greater surface dimensions than females These baseline results provide a detailed insight into the changes in the structure of the pubic symphysis with ageing and sexually
dimorphic features associated with the cortical and trabecular bone profiles

Morphometric modelling of ageing in the human pubic symphysis : sexual dimorphism in an Australian population

The backbone of Europe : health, diet, work and violence over two millennia

OBJECTIVES Cementochronology based on annual deposition of acellular cementum is acknowledged for its superior performance for estimating age-at-death but is also disregarded because of its suspicious effectiveness. This article aims to provide a standardized framework for the validation of the technique and to define and test cementochronology's performance and limitations. MATERIALS AND METHODS To determine the boundaries of the cementum aging technique, we applied a certified protocol on a sample of 200 healthy canines from individuals of known age, sex, postmortem, and inhumation intervals from anthropological and anatomical collections. We scored readability and preservation of cementum and measured the agreement between estimates, i.e., the precision, and assessed the quality of the accordance between estimates and chronological age, i.e., the accuracy. To investigate the applicability on ancient material, 200 additional canines extracted from archeological assemblages were included. Accuracy and precision were analyzed for each age group in considering postmortem intervals and taphonomical conditions. RESULTS A strong correlation was found between chronological age and estimates (r = .927; p = .000) but results reveal an association between readability of incremental lines and chronological age (p < .05) and a notable difference in both precision and accuracy between individuals under and over 50 years. Results also demonstrate that taphonomy can be a serious obstacle increasing imprecision by a factor of three. DISCUSSION Improperly adopted, cementochronology can lead to precise but inaccurate estimations. If methodological, physiological, and taphonomical factors are taken into account, then, and only then, cementochronology will serve as a versatile and powerful tool for age-at-death estimation.

Age at death estimation by cementochronology: Too precise to be true or too precise to be accurate?

Objectives
This analysis seeks to determine whether differences between real and estimated chronological age (CA) with biological age (BA) in skeletal individuals reflect variability in aging.

Material and methods
A total of 87 individuals of two samples, ranging from 20 to 94 years old, were analyzed. One, partially documented, belongs to a Mexican skeletal collection dating to the 20th century; the other is an assemblage of prehispanic individuals from different archaeological sites. In all specimens, the tooth annulation method (TCA) was applied to estimate CA, while—excluding individuals older than 80 years—auricular surface (AS) and pubic symphysis (PS) methods were used to estimate BA. Statistical analyses were conducted to identify correlations and significance of the differences between CA vs. TCA, CA vs. AS/PS, TCA vs. AS/PS. Sex of individuals was assessed for its influence in aging.

Results
The use of TCA to estimate CA was successful for most individuals. A strong correlation was found between CA vs. TCA, CA vs. AS/PS, TCA vs. AS/PS and their differences were significant but variation in these were found when assessed by separate age groups. Sex did not influence such differences.

Discussion
TCA can be used to estimate CA and its differences with BA, being less than 10 years, are similar to those found in living populations. Differences between CA and BA are due to intra-population variability, which could be the consequence of individual differences in aging. More research is needed to have confidence that under- and overestimations of BA are indicators of aging variability at the level of the individual.

Lourdes R. Couoh

Papers

Differences between biological and chronological age-at-death in human skeletal remains: A change of perspective.