Your smile is probably one of the first things someone notices about you.
Now experts have discovered that the shape of our teeth may have been influenced by Neanderthals.
Research has shown that interbreeding with ancient human species from thousands of years ago still has lasting genetic effects on some people.
And it has led to significant differences in teeth between ethnic groups – especially for Europeans who inherited the gene.
The team, made up of researchers from University College London (UCL), analyzed data from 882 volunteers in Colombia of mixed European, Native American and African descent, including dental crown measurements derived from 3D scans of dental plaster casts.
They compared these measurements with the participants’ genetic information and identified 18 genomic regions that influence the size and shape of different groups of teeth.
It is believed that one of the genes was inherited from Neanderthals as a result of interbreeding with ancient humans.
Carriers of the gene have thinner incisors: the eight teeth at the front of the mouth.
Genetic variants that determine the shape of your teeth include a gene inherited from Neanderthals, the scientists report (file photo of Neanderthal skull)
The photo shows an example of the dental scans that researchers used to measure tooth dimensions. However, they don’t know if this comes from a person who carries the Neanderthal gene. The blue teeth show the arrangement of the teeth in our lower jaw as it would be naturally. This is called our dental arcade. The white teeth are aligned versions of the same teeth, where they are all aligned in the same direction: width, height, thickness
Interestingly, this genetic variant, which contributes to tooth development, was only found in people of European descent.
In general, people of European descent also had smaller teeth.
Lead author Dr Kaustubh Adhikari said that although this gene causes people to have thinner teeth, it does not mean they are more sensitive or prone to cracking.
“The ‘thickness’ of the incisors we are talking about is the total size of the incisor from front to back, not the thickness of the enamel layer,” he said.
‘The variation in overall thickness we observe, given that they are all healthy people without dental deformities, is modest.
‘Our study volunteers did not have hyper-thin teeth that might have been more sensitive or delicate.
‘In other words, the slightly thinner teeth that some of these people have, because of the gene we identified, are not a bad thing.
“So it’s nothing to worry about; it’s all part of normal human variation.’
Neanderthals were an early relative of humans who went extinct about 40,000 years ago, although their time on this planet overlapped with that of modern humans (homo sapiens). The photo shows a recreation of a Neanderthal woman
Although a thin layer of enamel on the teeth can affect whiteness, Dr. Adhikari said that is not the case in this case.
‘Teeth sensitivity and whiteness are usually affected by enamel – the thin but strong layer that covers the outside of your teeth,’ he said.
‘The genes that influence enamel are different from the genes we found in our research. That’s no surprise, because we didn’t study the enamel, we just studied the overall size of the tooth.
“As far as we understand, the two things are controlled by somewhat separate biological processes.”
Co-lead author Professor Andrés Ruiz-Linares added: ‘Our findings do not shed light on whether the genes that identify tooth shape have been selected in evolution for particular benefits for dental health.
‘It is therefore possible that the genes have been selected because of the influences they have in other areas, with tooth shape differences as a side effect.’
The study’s lead authors previously found that genes inherited from Neanderthals may influence the shape of our noses and also contribute to greater overall pain sensitivity.
Their findings were published in the journal Current Biology.