Time of occurrence and width of accentuated lines in the enamel of primary incisors from mediaeval skeletal remains from north-central Poland: A further contribution to the explanation of early childhood mortality in past populations

Abstract

ObjectivesPhysiological disturbances experienced during the early stages of biological development may have an impact on later periods of ontogenesis. The purpose of this study was to assess whether there is a correlation between early childhood mortality in archaeological populations and the age of onset of such disruptions in the course of prenatal and postnatal development. Material and methodsPrimary incisors were taken from 55 individuals who died at the age of 2–6 years and were buried in a mediaeval cemetery located in Brześć Kujawski in the region of Kujawy. The study material was divided into children who died at the age of 2–3 years (n = 29) and those who died at the age of 4 years and later (n = 26). Each tooth had at least one visible postnatal accentuated line. The distance between the neonatal line (NNL) in the lateral enamel and any visible accentuated line (AL) was measured and divided by the local daily enamel secretion rate in order to estimate the time of onset of the AL. The width of ALs was also measured. ResultsThe average age of onset of the first AL in children who died before 4 years of age and in those who died older was 56 and 59 days after birth, respectively, with the difference not being statistically significant (Z = 0.56; p = 0.576). However, children who died younger revealed wider ALs (Z = 2.06; p = 0.039). ConclusionThese results indicate that in past populations childhood mortality was not influenced by the exact time of occurrence of unfavourable factors in the early postnatal period, but rather by environmental conditions in the perinatal period and the first month of life shaping the individual predispositions of the response to them.