The Dental Anthropology Group at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) has recently published a study in the Journal of Anatomy, which analyzed the enamel and dentin dimensions of deciduous (or milk) canines from some of the most representative samples from the Lower and Middle Pleistocene, which include Neanderthals and hominins from the Gran Dolina and Sima de los Huesos sites (Sierra de Atapuerca, Burgos).

The objective of this study, in which the technique of micro-computed axial tomography (micro-CT) was used to explore the dental tissues, was to assess the resemblances and differences observed among the different samples of milk teeth, both fossil and modern, as well as to evaluate the degree of similarity with the enamel and dentin in the permanent dentition of those populations, specifically in the canines.

The results obtained show that, although there are certain similarities between modern deciduous and permanent canines, this is not found in the fossil populations. “The histological pattern of the deciduous and permanent canines does not offer a comparable image in fossil hominins”, states the researcher Cecilia García Campos, lead author of this study.

Valuable in paleohistology

Most of what we know about the internal anatomy of teeth in the human evolutionary lineage comes from studying the permanent dentition. However, the deciduous teeth, because they form early and develop rapidly, are not so strongly influenced by hormonal or environmental changes taking place over the life of the individual as the permanent dentition is.

“The deciduous teeth offer a simpler vision of the processes involved in regulating tooth size, and in particular, the dimensions of the enamel and coronal dentin, than the permanent ones do. Therefore, studying them is very valuable in paleohistology”, explains García Campos.

Ratón Pérez Collection

Apart from fossil teeth, this research availed of two extensive collections of teeth from modern humans of European descent as dental samples for comparison, one of which, the CENIEH Ratón Pérez Collection, was created to address the shortage of representative samples of deciduous teeth for scientific purposes.

The CENIEH Dental Anthropology Group, together with the same Center's Scientific Culture and Innovation Unit (UCC+i), began a campaign to collect milk teeth in 2014 to create the Ratón Pérez Collection for reference. Currently, this Collection holds over 3000 dental pieces, which are being analyzed for anthropological studies of various types that will appear over the next few years.