Growth disturbances in the Neolithic of Liguria from the analysis of perikymata

Autor: Orellana-González, Eliza, Bocaege, Emmy, Moggi-Cecchi, Jacopo, Sparacello, Vitale Stefano, Dori, Irene
Přispěvatelé: Université de Bordeaux (UB), De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: 53rd scientific conference of Prehistory and Protohistory of Liguria
53rd scientific conference of Prehistory and Protohistory of Liguria, Oct 2018, Genova, Italy
Popis: International audience; With the shift to a Neolithic way of life, humans experienced a major change in environmental stressors, probably caused by changes in diet and ways of subsistence, population packing, and the spread of new pathogens. At the same time, possible competitive advantages of Neolithic farmers when compared to previous hunter-gatherers included the availability of weaning foods, which dramatically reduced the length of infant breastfeeding, and allowed for shorter inter-birth intervals. Immature individuals are the most susceptible to environmental stressors, and are therefore the most representative sample to describe to the overall Dzwell-beingdz of a population. Studies of stress in past populations are often based on a suite of skeletal and dental features (e.g. enamel hypoplasia, cribra orbitalia, periostotic lesions, Harris lines, and long bone dimensions) associated with either developmental disruptions, non-specific bone reactive processes, or nutritional deficiencies. Among these, the study of enamel hypoplasia has some advantages. Enamel hypoplasia is a reduction of normal enamel thickness due to events occurring during amelogenesis. Such defects are commonly considered a nonspecific indicator of systemic growth disturbances as the causes determining their occurrence may be multiple (nutritional deficiencies, diseases, infections, metabolic disorders, etc.). In contrast to other non-specific stress indicators, the analysis of enamel hypoplasia presents some advantages; for example, it is possible to quantify the frequency, the age of occurrence, the duration and the periodicity of the defects, thereby enabling detailed comparisons between populations and groups with social and demographic differences.To date, few studies have taken into account the dental remains from Neolithic Liguria, and in the existing dental studies, tooth development has not yet been considered. In this communication, we review the state of the art of dental anthropology in Liguria, and we present the results of new studies conducted in a sample of Neolithic subadults from Liguria by the DEN.P.H. project using advanced methodologies. In particular, we studied linear enamel hypoplasia (LEH) using a new methodological approach based on the analysis of tooth surfaces by macro-photos and microscopic observations. These methodological enhancements allowed us to observe several parameters of LEH: number of defects, the duration of each LEH, the interval between successive defects, age at first defect, and the total amount of dental formation time affected by growth disruption. Analyses were made on high-resolution dental casts of relatively unworn anterior upper and lower teeth of 24 children and adolescents from Ligurian sites in the Finalese area (Arene Candide, Arma dellǯAquila, Bergeggi, La Matta/Sanguineto, Parmorari, Pollera, and Strapatente). Macro-photographs were taken of all crowns in order to identify the presence of defects. Using ImageJ, it was possible to measure the total height of the crown for each photo, divide this into deciles and visually identify defects per decile. Defects were then confirmed using a microscopic method. Teeth surfaces were imaged and analyzed using confocal microscopy (Leica Sensoscan 6.4, x20 magnification). This allowed for the identification of the perikymata (incremental growth lines on the enamel surface) of each individual tooth crown and the perikymata spacing profile, which was measured from the incisal to the cervical margin. An individual chronology for LEH formation was developed and systemic growth perturbation were detected by matching defects in at least two different teeth of the same individual. Using this approach, it was possible to obtain high-resolution data that will be useful to make inferences on childhood health and ontogenetic disturbances in the Neolithic.
Databáze: OpenAIRE
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