Assessing weaning stress - Relations between enamel hypoplasia, delta(18)O and delta(13)C values in human teeth obtained from early modern cemeteries in Wroclaw, Poland.

OBJECTIVES: The aim of this paper is to assess linear enamel hypoplasia (LEH) on canines of adults from early modern Wroclaw cemeteries to compare delta(13)C and delta(18)O values in enamel formed before, during and after LEH formation, and to attempt to find a link between the selected indicators of the weaning process. MATERIAL AND METHODS: 15 permanent canines with visible LEH were selected for analysis. Age at LEH formation was estimated using the Reid and Dean method. The perikymata count was used to estimate the duration of LEH formation. Incremental stable oxygen and carbon isotopes analysis was performed on tooth enamel to infer stress related to weaning and dietary patterns. Kruskal-Wallis ANOVA, Mann-Whitney U test and Spearman correlation were used in statistical inference. RESULTS: The average age of LEH formation was 3.14 years, with an average duration of 111 days. Stable carbon isotope values consistently increase in 73% of the individuals sampled. The values of delta(18)O do not show a dominant pattern. The average value of delta(13)C increases over the time of enamel formation. The delta(13)C values collected below LEH were negatively correlated with delta(18)O values and the duration of LEH termination. CONCLUSIONS: Marking of carbon and oxygen isotopes indicates different stages of weaning. Advancements in diet change (determined by higher delta(13)C) corresponds with faster recovery after physiological stress episode. There is no evidence for different breastfeeding models between distinct parishes in early modern Wroclaw.