From discovery.com: Unbrushed Teeth Reveal Ancient Diets.

Ick factor aside, ancient tartar-encrusted teeth may be a biological gold mine for scientists, thanks to a new technique for extracting food particles from teeth that once belonged to prehistoric humans.

The method already has solved a mystery surrounding what early coastal Brazilians ate.

In the future, similar studies may reveal clues about other ancient diets, particularly in areas with little plant preservation from earlier times. [continue]