[DOCTOR BRUCE] Hello Alex. How are you today?

[ALEX] Good.

DOCTOR BRUCE] I'm Doctor Bruce. Nice to meet you. Have a seat. I'm going to take a look at your teeth today, okay?

[ALEX] Okay.

[DOCTOR BRUCE] Let me set this chair back for you

Okay, now what we're going to do is put the camera on your mouth and then you'll be able to actually see it up on the screen, okay? Here it comes.

[JOAN CARTAN-HANSEN] Whoa, looks good in here! You've obviously been brushing.

Hey, do you know how important your teeth are to staying healthy?

[ALEX] Huh-uh.

[JOAN] Okay. Let's start with the basics. Roll em!

You can tell a lot about an animal by looking at its teeth. Birds don't have teeth. They use their beaks. Frogs don't have teeth. They have a sticky tongue.

Now cows, cows have teeth. They are plant eaters and have large broad teeth to grind up their food. Beavers have sharp front teeth to snap branches and meat eaters like wolves have sharp fangs to rip meat off the bones and shred their food.

Humans have a combination of all of these kinds of teeth - not as sharp as a beavers or as broad as a cows but our teeth allow us to eat different kinds of food.

Adults have 32 teeth. The front are your incisors used for biting. Next are the canines or the cuspids. They are used for tearing food And the big flat teeth in the back of your mouth are pre-molars and molars. They're used for chewing.

Your teeth are held in place by your jaw bones and the soft pink tissue covering your jaw bones and surrounding your teeth is called your gums. All your teeth - gums and bones - work together to help you speak, eat and even yawn. You get two sets of teeth. Your baby teeth, you start losing them when you're about 5 or 6 and then you get your adult teeth. Now your adult teeth, take care of them. When you lose them, you don't get any more.

A tooth is made up of three parts - the white covering on the top is called the enamel. It's the hardest substance in your whole body. Next is a yellowish substance called dentin which surrounds the pulp. That's made up of nerves and blood vessels. The nerves inside your teeth send signals to your brain to help you know how hard you're biting.

When you eat you leave small bits of food on your teeth and millions of bacteria feast on your leftovers. They leave behind a sticky coating called plaque and plaque makes acid, a chemical that slowly eats through the tooth enamel and the dentin and that leaves a hole or a cavity. But brushing and flossing helps prevent plaque and prevent cavities.

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