Detecting menarcheal status through dental mineralization stages?

Menarche is an indicator frequently used to study variation in growth, development, and related health conditions among members of living populations. As a life event, menarche is often associated with changes in an individual's social identity. The reproductive lifespan, which for females starts with menarche, is a paramount feature of palaeodemographic studies. Determination of menarche status from the skeletal remains of individuals of past populations can be obtained by assessing the developmental status of the iliac crest, as well as the hand and wrist bones, which are, unlike teeth, often poorly recovered in bioarchaeological contexts. The present study seeks to evaluate the link between dental mineralization and menarche in a population of known menarche status. The relationship between permanent teeth mineralization and menarche status was investigated by using data of developing permanent teeth (167 radiographs) rated in accordance with the well-known standards of Demirjian et al. and Moorrees et al. collected among 73 living French females of known menarcheal status. Using correlation ratios, GLMM and CART algorithm, menarcheal status is correlated with mineralization of the premolars. Menarcheal status is predicted correctly for 92 and 77% of radiographs of the learning and validation samples, respectively. Although promising, the results require caution prior to generalization to other populations. The age of menarche in this particular sample may simply coincide with the development of the premolars in this particular sample. Therefore, further investigation applied to populations with various mean ages of menarche is required in order to provide new evidence of variation in human growth and development from the correspondence between the mineralization of the permanent teeth and menarche.

Dental age assessment in children: a comparison of four methods in a recent French population.

The aim of this study was to analyze the accuracy and the reliability of four methods of dental age estimation (Demirjian, Willems I, Willems II, and Chaillet standards) in a French population. Orthopantomograms of 743 children aged between 4 and 15 years were used. The Demirjian standards gave a consistent overestimation of dental age compared with chronological age (+0.45 and +0.46 years for girls and boys, respectively). We found that three modified methods were more accurate for both sexes than Demirjian's method: the Willems I method appeared to be more suitable when the sex and ethnicity are both known (-0.09 and +0.14 years for girls and boys, respectively); the Willems II method was more accurate for children of unknown sex (mean difference = 0.00 years), and the Chaillet method was found to be more accurate than the Demirjian method, but less accurate than the Willems I method (-0.59 and -0.18 years for girls and boys, respectively).