Application of non-adult Bayesian dental age assessment methods to skeletal remains: the Spitalfields collection

The aim of this study was to test with non-adult skeletons the quality of a recently published dental age assessment method based on Bayes' theorem. The test sample consisted of dental X-rays from 16 individuals (range 2.6–15.1 years) recovered from the crypt of Christ Church, Spitalfields, London, for which age-at-death and sex were known. The training sample consisted of dental X-rays from 1346 girls and 1040 boys (range 1.9–16.0 years). Bayesian dental age assessment method was alternatively used with dependent and independent assumptions; the dependent Bayesian method (DBM) and independent Bayesian method (IBM), respectively. Moreover, both DBM and IBM were used alternatively with sex-specific standards and with non-sex-specific standard. Due to the training sample age distribution, both methods are efficient between 5.0 and 14.0 years. Whatever the method or the sex standard used, when dental age was different from chronological age, the discrepancy did not exceed one age group of one year. DBM produced tighter dental age 100% confidence intervals than IBM for the majority of assessments. The observed stability between results produced according to the type of sex standard used (i.e. sex-specific or non-sex-specific), and the number of teeth studied (range 4–7), is worthy of note for both archaeological and forensic contexts.