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

Abstract

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.

Skeletal and dental indicators of health in the late mediaeval (12–15th century) population from Nin, southern Croatia

“…during the transition from the diet based on the sterile breast milk to the diet rich with microorganisms. However, it is important to stress that serious doubts about this interpretation have been raised (Blakey et al, 1994), and that serious methodological problems related to the age assessment of the defects have been identified (Hodges and Wilkinson, 1990). Additionally, Ritzman et al (2008) reported that histological studies provide significantly higher age estimates than the commonly used macroscopic methods and this difference is particularly marked in early forming hypoplastic defects.…”

Patterns of dental enamel defects at ancient Mendes, Egypt

“…We then translated the positions of defects on permanent teeth into a crude estimate of the age at which the stress episode occurred, based on the algorithm developed by P. Walker (personal communication; see Appendix) from the developmental sequence by Massler et al (1941) of enamel mineralization. Although tooth size variation has been shown to affect the age estimate of an enamel hypoplastic defect, the associated error was shown to be limited to approximately Ϯ6 months in an archaeological sample (Hodges and Wilkinson, 1990), and therefore we have not further corrected our gross estimates of age-at-insult. Two thirds of the sample were scored by both authors, and presence and location of defects showed high replicability.…”

Enamel hypoplasia in a Canadian historic sample

“…This diagram is intended to take into account the problem of ''buried'' enamel (Skinner and Goodman,1992). In addition, the sample specific technique of reporting age of occurrence of defects as recommended by Hodges and Wilkinson (1990) was employed for the maxillary central incisor and the mandibular canine. This involves calculating the percent of crown height for the position of defects based on sample mean crown heights.…”