Although many people are concerned about the photogenic structure of their teeth, chances are they don’t think about the shape of individual teeth. Well, you should—because it can be determined in part by your Neanderthal ancestry.
An international team of researchers co-led by Kaustubh Adhikari from University College London (UCL) has discovered differences in teeth between tribes, including an apparent trait determined by a gene found in Neanderthals. Their study, published on December 12 at Current Biologyit may one day help diagnose and treat genetic dental conditions.
Researchers, including experts from Fudan University in China, used 3D scans of dental casts to analyze the dental measurements of 882 European, Native American, and African volunteers. They then compared these dimensions to the volunteers’ genetic data and identified 18 genetic regions involved in different tooth sizes and shapes. Notably, 17 of these regions were identified for the first time as being linked to tooth size.
“Teeth can tell us a lot about human evolution, as well-preserved ancient teeth are very important to archaeologists, they shed light on important events such as when we switched to cooked food and human teeth began to shrink. But little is known about the genetic basis of modern human differences in tooth size, partly because of the challenges of measuring teeth,” Adhikari said in a UCL statement. “We have now identified many genes that influence the development of our teeth, some of which cause differences between races.”
Interestingly, scientists suggest that one of the identified genes comes from Neanderthals, ancient humans who were related during our brief prehistoric coexistence. A genetic variant, found only in volunteers of European ancestry, was associated with thinner incisors (measured from front to back). The researchers also noted that people with this variant tend to have smaller teeth altogether. Additionally, the team found that the EDAR gene, previously linked to incisor shape in East Asians, also affects the width of all teeth.
However, “our findings did not shed light on whether the genes that determine the shape of the teeth were selected by evolution due to certain advantages of dental health, so it is possible that the genes were selected because of the influences they have in other areas, the difference in the shape of the teeth leading as a negative effect,” he explained. Andrés Ruiz-Linares from UCL and Aix-Marseille University, who jointly led the study. Simply put, researchers aren’t sure why genes are designed to negatively affect teeth in this way.
“Some of the genes that contribute to normal changes in tooth size among healthy individuals may contribute to pathogenic changes, such as teeth that fail to grow or in other dental health conditions,” said Qing Li of Fudan University, who led the collaboration. learn. Pathogenic mutations are genetic differences that increase a person’s chance of developing a particular disease or genetic disorder. In other words, the genes that determine tooth proportions may also determine health problems.
As a result, “we hope that our findings can be useful in medicine, if people with certain dental problems can be genetically tested to aid in diagnosis, or if some dental problems can one day be treated with gene therapy,” added Li.
It remains to be seen how this research can lead to practical medical applications. Meanwhile, Neanderthal teeth join a host of other traits we may have inherited from our long-lost relatives, including pain tolerance and nose shape.
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