The CENIEH leads a study based on the Ratón Pérez Collection that analyzes 428 deciduous molars from 211 boys and girls and shows that differences between the sexes are small and that the sizes of different teeth are closely related within the same individual
The Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) has led a study, published in the American Journal of Biological Anthropology, that analyzed 428 upper and lower deciduous molars from 211 boys and girls in the Ratón Pérez Collection. The results reveal that differences between the sexes are generally small and that there is a close relationship between the sizes of the different molars within the same individual.
The study includes the largest known sample to date of associated deciduous molars, that is, several milk teeth belonging to the same individual. This has made it possible to investigate not only how the size of these teeth varies within a population, but also how the different teeth of the same person are related to one another.
The analysis shows that differences between boys and girls are small and inconsistent and are concentrated mainly in the second deciduous molars, particularly the lower ones. Much clearer, however, is the relationship between the sizes of the different teeth: individuals with larger first deciduous molars also tend to have larger second molars. This association is observed in both the upper and lower dental arcades.
The relationship is particularly strong for measurements that reflect overall crown size, while crown proportions show weaker associations. This pattern suggests that the different molars do not vary independently, but that shared biological processes contribute to coordinating their development.
“The opportunity to study several teeth from the same donor has enabled us to show that the sizes of the different molars are closely related within the same individual, pointing to the existence of shared biological processes that coordinate their development,” explains Marina Martínez de Pinillos, a CENIEH researcher and first author of the study.
These data are also relevant to the study of past human populations. Understanding how teeth vary and are related to one another in present-day populations provides a reference for better interpreting the differences observed in archaeological and fossil remains. The study also shows that relatively simple measurements of the dental crown can provide valuable information about the development, integration and variability of the human dentition.
The Ratón Pérez Collection as a reference resource
This research was made possible by the Ratón Pérez Collection, created in 2014 at the initiative of the CENIEH Scientific Culture and Innovation Unit (UCC+I) from donations of milk teeth by boys and girls from around the world. Today, the collection comprises more than 6,500 dental specimens accompanied by individual information about their donors.
One of its main advantages for research is that it preserves several teeth from the same individual. This makes it possible to study the relationships among the different teeth within a dentition, something that is particularly difficult to investigate in archaeological and fossil populations, where samples are usually much smaller and more fragmentary.
These characteristics have made the Ratón Pérez Collection a reference resource for investigating the development and variability of the human dentition and for generating comparative data that can help us better understand our evolutionary past.