One of the oldest and most enduring explanations for what causes tooth decay was the tooth worm, first noted by the Sumerians around 5000 BC. They believed that tooth decay was the result of a "tooth worm" making holes in the teeth.
The idea of the tooth worm has been found in the writings of the ancient Greek philosophers and poets. It has also been found in such places as ancient India, Japan, Egypt, and China. This ivory carving depicts the havoc caused by such a voracious tooth worm.