Effect of tooth size on the ageing and chronological distribution of enamel hypoplastic defects

The location of enamel hypoplastic defects on the tooth crown has been used to determine the age of an individual at the time the defect-producing stress occurred. The assumptions made in following this methodology are examined, and one in particular, that tooth size variation has a minimal impact on ageing and subsequent chronological distributions, is tested. Teeth with no occlusal or minimal wear and with enamel hypoplasias were measured for crown height and the location of the defect on the crown. Two samples are used, one comprising a series of archaeological specimens and the other from modern clinical extractions. The chronological distributions of the defects are determined by three different methods: one is based on a tooth mineralization chart; the second method uses the same chart but incorporates individual crown heights; and the third method adjusts the chart for the sample's mean crown heights. Significant differences between the age estimates are observed in both the modern and archaeological samples. Tooth size does affect the ageing of hypoplastic defects and the chronological distributions. By adjusting the mineralization chart for the sample's mean crown heights, the significant differences in age estimates can be corrected.