November 24, 2011
Orthodontic Problems Linked To Food Gathering
A new study has found that many of the orthodontic problems faced by people in industrialized nations are due to their soft modern diet.
The research from the University of Kent tested the theory that the transition from a hunter-gatherer to an agricultural subsistence strategy has had a knock-on effect on the growth and development of the human skull and lower jaw.
The team compared the shape of the skull and lower jaw of 11 globally distributed populations against models of genetic, geographic, climatic and dietary differences.
They found that lower jaw shape, and the upper palate, was related to the dietary behavior of populations, while the cranium was related to the genetic relationships of the populations.
The lower jaw reflects whether populations are primarily hunter-gatherer or agriculturalist in nature. This suggests, according to the researchers, that chewing behavior causes the lower jaw to grow and envelop differently in separate subsistence groups.
The researchers said that the hunter-gatherer groups had longer and narrower lower jaws, which shows that these groups had more room for the teeth to not overcrowd.
The agriculturalists had shorter and broader lower jaws, which increases the likelihood of dental crowding.
"Chewing behavior appears to cause the lower jaw to develop differently in hunter-gatherer versus farming populations, and this holds true at a global level. What is interesting, is that the rest of the skull is not affected in the same way and seems to more closely match our genetic history," Dr von Cramon-Taubadel, a lecturer in Biological Anthropology with research interests in human and primate evolution, said in a press release.
The study was published in the Proceedings of the National Academy of Sciences.
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