Need braces on your teeth? Your ancestors might be to blame

By Carrie Johnson Weimar • Published: February 2nd, 2012
Category: Health in a Heartbeat

Wearing braces on your teeth has almost become a rite of passage for children in America. It’s very hard these days to escape the requisite two or three years with a mouth full of metal. So what is to blame for this influx of crooked teeth? New research shows it might be because our long-ago ancestors switched from hunting and gathering to farming.

At least that’s the theory of an anthropologist, who believes the move toward foods that were easier to chew had a big effect on the size and shape of human jawbones. His findings were recently published in the Proceedings of the National Academy of Sciences.

To test his theory, the anthropologist studied the shape of human skulls and jawbones from 11 different countries. He included skulls from countries such as Italy and Japan, where there has been a long tradition of eating cultivated foods, and also places like Australia and Alaska, where there were more hunters and gatherers.

He found a big difference in the size and shape of people’s jawbones. The hunters and gatherers tended to have longer, narrower jaws that left plenty of room for teeth. In contrast, the farmers had jaws that were more short and squat.

What accounts for this difference? Well, hunters and gatherers ate a widely varied diet, and needed strong jaws to be able to chomp through whatever was on the menu that day. The farmers tended to eat the same things over and over: corn, grain, rice and wheat.

So while the size of human teeth has remained unchanged, the space available for those teeth shrank. That means the teeth are more crowded, which can make them crooked.

Sorry, kids. In today’s environment, it’s pretty unlikely we will ever go back to hunting and gathering. So it probably means enduring a few years of being called metal mouth before showing off your shiny — and straight — set of chompers.