Molar crown height: not always a reliable method for the evaluation of age-at-death

In this study, we tested the validity of molar crown height, which changes according to the degree of tooth wear, for the evaluation of age-at-death. The sample consisted of 372 first and second molars (lower and upper) from 157 individuals of known sex and age-at-death. For each molar, we measured the height of the two cusps most subjected to wear (protocone and hypocone for the upper M1 and M2; protoconid and hypoconid for the lower M1 and M2). The correlation between crown height and age-at-death was assessed by linear regression analysis. The resulting models were not very robust since a significant correlation was only found for a small part of the sample, at best (maxillary M1) around 35%. The result slightly improved when bucco-lingual diameter (BL diameter), ante-mortem tooth loss and dental caries were considered, mainly for the maxillary M2 for which the model using age-at-death and BL diameter as independent variables explained 47% of the sample (p < 0.001).The low efficacy of the models in clarifying the relationship between crown height and age-at-death was probably due to natural intra-population variability of crown height and other factors such as individual differences in tooth wear and enamel resistance.