As NPR reports:
Prehistoric humans didn’t have toothbrushes. They didn’t have floss or toothpaste, and they certainly didn’t have Listerine. Yet somehow, their mouths were a lot healthier than ours are today.
“Hunter-gatherers had really good teeth,” says Alan Cooper, director of the Australian Centre for Ancient DNA. “[But] as soon as you get to farming populations, you see this massive change. Huge amounts of gum disease. And cavities start cropping up.”
And thousands of years later, we’re still waging, and often losing, our war against oral disease.
Our changing diets are largely to blame.