Disturbi dello sviluppo in un campione umano del Neolitico della Liguria tramite l’analisi dell’ipoplasia dello smalto dentario

This study reconstructs patterns of linear enamel hypoplasia during growth among agropastoral communities belonging to the Square Mouthed Pottery Neolithic (c. 4800-4400 cal. BCE) from Liguria, (northwestern Italy). Dental growth disturbances between the ages of 1 and 5 years were assessed to provide a developmental perspective on biocultural adaptations that accompanied the transition to a Neolithic subsistence in a key region in the Mediterranean. We studied 43 unworn/minimally worn permanent anterior teeth belonging to 13 individuals. Linear enamel hypoplasia defects were assessed via high-resolution macrophotos of dental replicas. The age at which growth disturbances occurred was calculated from perikymata counts, and hypoplastic defects which could be matched between two or more teeth were considered as systemic disturbances. Statistical analysis of differences in linear enamel hypoplasia prevalence during growth stages (0.5 years increments) was conducted via Generalized Linear/Nonlinear Models (GLZ) using a quasi-Poisson distribution for count data, and via Friedman ANOVA. Correlations between the age of linear enamel hypoplasia appearance and age at death were assessed. Results indicated that the number of matched defects per individual ranged between 2 and 12. The mean matched hypoplastic linear defect per individual was highest in the 2.5-2.99 age category, with a significant increase relative to earlier growth stages, followed by a decline. This signal of increased developmental disturbances may reflect life history adaptive changes in the local ecology of Neolithic Liguria, where several individuals with osteoarticular tuberculosis have been recorded. Age at first defect was negatively correlated with age at death and positively with the total number of defects, suggesting that early stress may have affected survivorship.