The enamel on our teeth is the hardest tissue on the human body. A new study looks at the nanoscale structure of enamel from teeth dating as far back as 18 million years ago to see how it's changed.

Scientists discovered true teeth growing on the head of the spotted ratfish, a distant shark relative. The toothed structure, called a tenaculum, helps males hold onto females during mating. Genetic ...

You only get 52 teeth in your lifetime: 20 baby teeth, followed by 32 adult teeth. It’s not like that for all animals. Some, like rodents, never replace their teeth. Others, like sharks, keep ...

It happens to everyone when you least expect it—a quick swig of hot chocolate after coming in from the cold and ouch! Your teeth react to the temperature change as if you had been chewing on tin foil.