A genome-wide association study identified 18 genetic regions that influence tooth size in modern humans. The research found evidence that some dental traits were inherited from Neanderthals through interbreeding.

In the study, published in Current Biology, researchers analyzed dental measurements and genetic data from 882 Colombian volunteers of mixed European, Native American, and African ancestry. This study examined genetic factors controlling variation in human tooth dimensions.

The researchers measured mesiodistal diameter, buccolingual diameter, and crown height across different tooth types. Through genome sequencing data analysis, they identified genes determining tooth size and shape.

The study found that variants in the HS3ST3A1 gene region, which affects upper incisor width, were inherited from Neanderthals. These variants appeared commonly in Europeans but rarely in other populations.

PITX2, a gene involved in tooth development, influenced premolar width. Mouse experiments showed changes in PITX2 activity altered molar size and shape.

The study revealed that variants in the EDAR gene increased tooth width following an anterior-posterior gradient, with stronger effects on front teeth compared with back teeth.

The researchers validated their findings through studies in a Chilean population and through dental measurements in mice. They conducted molecular analyses to examine how genetic variants affected tooth development. The researchers emphasized that dental dimensions varied by continental ancestry, with Europeans showing smaller teeth compared with individuals of African or Native American descent.

The researchers used three-dimensional scanning and automated measurement techniques for dental measurements, combining these with genetic analyses and laboratory studies.

The study received funding from the National Natural Science Foundation of China and European research organizations.

A disclosure statement was not made available at time of publishing.