MELBOURNE, Oct. 6 (Xinhua) -- An Australian study overturns the long-held belief that grooves on ancient human teeth were evidence of early "toothpicks" used for cleaning or pain relief.
The study compares tooth grooves and other root lesions across more than 500 teeth from 27 species of wild primates, according to a statement released Monday by Australia's Monash University, which led the study.
Researchers found that similar grooves can appear naturally, simply through chewing tough foods or from everyday wear, not just deliberate tooth picking.
It also found that deep V-shaped notches near the gumline known as abfraction, a common modern dental problem, are absent in both fossil and living non-human primates.
The findings suggest that abfraction is unique to modern humans, brought about by behaviors such as tooth grinding, forceful brushing, or acidic diets instead of natural chewing.
"The complete absence of abfraction in wild primates highlights that this condition, one of the most common seen in modern clinics, is not a universal problem, but uniquely human," said study Lead researcher Ian Towle of Monash University's Biomedicine Discovery Institute.
The evidence overturns a long-standing assumption in human evolution, and shows that some of today's most common dental issues are products of modern life, said the study published in the American Journal of Biological Anthropology. ■
