Child brides: the age estimation problem in young girls

Abstract

The aim of this work is to study a sample of girls coming from 15 different countries and using third molar maturity index, to assess the probability that a girl has reached the legal age of 18 years old or not. The studied sample consisted of 3228 Orthopantomograms of healthy female subjects coming from 15 different countries. The cutoff value of third molar maturity index (I_3M) = 0.08 was tested to discriminate adults (≥18 years) and minors (<18 years). X-ray images were processed by computer-aided drafting program ImageJ. The information on sensitivity and specificity of I_3M coming from the 15 countries was combined and pooled together using a bivariate Bayesian modeling approach. Specificity of the I_3M test does not change when country is considered, and its value remains greater than 85% for each considered country. The method is useful to determine the adult age of the girls involved in suspected early marriage both because of the high probability of correctly identify a minor and for the lack of difference observed in the results among nations.