Third molar development in South Africans and the probability of being 18 years of age

Abstract

Dental development is frequently used to estimate age in cases involving skeletal remains, mass disasters, children with no identification documents and asylum seekers. Limited data are available for South Africans around the critical age of 18 years. After age 14, the only available immature tooth to estimate age with is the third molar. European age estimation models are often followed and age of individuals estimated by using unrepresentative data. The aim of this study was to estimate whether a person is legally an adult, i.e., what is the probability of being younger/older than 18 years, based on third molar development. Retrospective panoramic radiographs of 1268 individuals aged 15–25 years were studied from the School of Dentistry, University of Pretoria, South Africa. Proportionate samples of males and females (633 and 635 respectively) aged 1–25 years of European and African ancestry (n = 705 and 563) were used. The developmental stage of the left upper and lower third molars for each individual was determined and scored according to the criteria developed by Solari et al. (2002). The probability of being at least 18 years of age at a given stage was determined for each population and sex, including a 95% confidence interval. The data demonstrated earlier maturation of African males and females of between 6 and 14 months compared to individuals of European origin in the last stage (stage H). Differences between males and females were noted with earlier maturation in males. The additional stages F1 and G1 improved the evaluation of third molar formation. This dental data, along with other skeletal data, will be used to develop a multifactorial model for age estimation in living South Africans.