Using cementochronology to assess the seasonality of catastrophic events in medieval mass graves (Kutná Hora-Sedlec, Czechia, 14th century): Preliminary results.

While season-of-death estimation using cementochronology is routine in archaeozoology, its use is much less frequent in bioarchaeology. Based on the character of the outermost increment (bright or dark), two seasons (spring/summer, autumn/winter) can be distinguished. Although many studies mention its potential and possible use in forensic anthropology or bioarchaeology, few exist with estimation results. This study aimed to apply cementochronology-a histological method based on counting and assessing regular circa-annual acellular cementum increments-to 42 individuals from medieval mass graves from Kutná Hora-Sedlec (Czechia, 14th century) to estimate the season-of-death. The mass graves belong to two stratigraphically distinct groups; written and archaeological sources relate them to two catastrophic events (the famine of 1318 and the plague epidemic of 1348-1350). Using cementochronology, we distinguished two distinct seasons corresponding to the two groups of graves, with individuals from the first group dying predominantly in spring/summer, while those from the second group died in autumn/winter. Taking into account the typical seasonal dynamics of epidemics, the results would be more in line with written sources. However, during the evaluation, we faced difficulties identifying the outermost increment and detecting the dark (thinner) increment; we recommend including only young and middle-aged adults in future studies, due to the difficulty of evaluation, and to consider the readability of the tissue (often affected by diagenesis). In conclusion, cementochronology has potential in the context of estimating the season-of-death, but the technical possibilities for enhancing the outermost increment need to be addressed, and the amount of data analysed expanded.

Protocol matters: A need for standardized procedure in cementochronology.

Cementochronology has long been associated in the literature with a high correlation between chronological and estimated age, and low differences between the two ages. The excessive accuracy was rather suspicious, and the method did not even appear in common forensic practice. An important step towards more widespread use of the method is the need to standardize work procedures, including indexes for recording the quality of cementum, preparation of thin sections and the age calculation. In our study, we used the standardized protocol for the preparation of thin sections in a set of Czech modern teeth of known age and sex. In the initial phase, 11.5% of the teeth were discarded due to severe caries in the medial part of the root. In a set of single extractions (55 teeth from 55 individuals), we focused on the detailed results of the age estimation, using precision and accuracy indicators. We also used different dental development data to calculate age, given inconsistencies in the use of eruption / mineralization. In a set of multiple extractions (68 teeth from 22 individuals), intra-individual variability was examined. The result of the application of the standardized protocol is an estimate of age with an absolute inaccuracy of -1.7 years and a relative inaccuracy of 5.4%. Calculation of precision and accuracy in the set of single extractions, however, showed the method's limitations: the imprecision measuring the variability of cementum increments counts increased with chronological age, as did the inaccuracy. The use of different dental development data did not significantly increase the accuracy of the age estimation results. Intra-individual variability remains poorly understood - in the set of multiple extractions the differences within one individual ranged between 0.9 and 10.8 years.

Multiple occurrence of premature polyarticular osteoarthritis in an early medieval Bohemian cemetery (Prague, Czech Republic).

OBJECTIVES: To highlight conditions that may cause early-onset degenerative joint disease, and to assess the possible impact of such diseases upon everyday life. MATERIAL: Four adults aged under 50 years from a medieval skeletal collection of Prague (Czechia). METHODS: Visual, osteometric, X-ray, and histological examinations, stable isotope analysis of bone collagen. RESULTS: All four individuals showed multiple symmetrical degenerative changes, affecting the majority of joints of the postcranial skeleton. Associated dysplastic deformities were observed in all individuals, including bilateral hip dysplasia (n = 1), flattening of the femoral condyles (n = 3), and substantial deformation of the elbows (n = 3). The diet of the affected individuals differed from the contemporary population sample. CONCLUSIONS: We propose the diagnosis of a mild form of skeletal dysplasia in these four individuals, with multiple epiphyseal dysplasia or type-II collagenopathy linked to premature osteoarthritis as the most probable causes. SIGNIFICANCE: Combining the skeletal findings with information from the medical literature, this paper defines several characteristic traits which may assist with the diagnosis of skeletal dysplasia in the archaeological record. LIMITATIONS: As no genetic analysis was performed to confirm the possible kinship of the individuals, it is not possible to definitively assess whether the individuals suffered from the same hereditary condition or from different forms of skeletal dysplasia. SUGGESTIONS FOR FURTHER RESEARCH: Further studies on premature osteoarthritis in archaeological skeletal series are needed to correct the underrepresentation of these mild forms of dysplasia in past populations.

The impact of using new and conventional methods for the age-at-death estimation in a Czech medieval population (Mikulcice, 9th-10th century): the relationship between age-at-death and linear enamel hypoplasia.

Recent advances in age-at-death estimation from the skeleton indicate that some of the most commonly used methods based on linear regression provide different results compared to new techniques using Bayesian statistics, and underestimate individuals over 60 years old which leads to biased prehistoric lifespans. The question is how the choice of age-at-death estimation method can influence subsequent comparisons between different populations or further analysis, such as assessment of the effect of early stress on mortality in adult individuals. The aim of our work is twofold: firstly, to test the differences between age estimation methods evaluating one indicator (the auricular surface), namely the original (Lovejoy et al. 1985), revised (Buckberry & Chamberlain 2002) and newly developed (Schmitt 2005) methods, on the Early Medieval adult population from Mikulcice - IIIrd church (Czech Republic, Central Europe). The secondary objective is to assess whether the different age distributions based on the different methods have an impact on age-dependent analyses, in this case the relationship between LEH and age-at-death. Our results showed that in the adult population from Mikulcice - IIIrd church, the original and revised methods provided different mortality profiles: the proportion of individuals older than 60 years acquired using Lovejoy's method was only 6.7%, while the newer methods increased the proportion to 26.7% (Buckberry & Chamberlain 2002) and 23.9% (Schmitt 2005). The choice of age-at-death estimation, and thus the different age distributions, also resulted in differences in the achieved age of individuals with and without stress markers, and specifically in the significance of the differences found. This finding seeks to draw attention to the fact that inconsistency in the use of different age-estimation methods can influence the results of further analyses and cause problems when comparing burial grounds.