These tooth models show the relative size comparison of a human tooth versus a rat tooth -- to give an idea of the technical challenges involved with performing dentistry on such a small scale.

lives among the trees and survives on nuts that it cracks open with its teeth. The Solomons are already home to eight other species of rat, but this is the first new discovery in 80 years.

A Harvard-led team just successfully used low-powered lasers to activate stem cells and stimulate the growth of teeth in rats and human dental tissue in a lab. The results were published today in ...