Uses and Kinds of Teeth
ASK: Do all of the teeth in your mouth look the same? Which are bigger? Which are sharper? Which are flatter? Why do you think you have different sizes and shapes of teeth?
DISCUSS: Teeth are used for different jobs in eating our food. They are different sizes and shapes so they can do different jobs in helping us eat. Each kind of tooth has its own function. The teeth in the front of your mouth have a different shape than the teeth in the back of your mouth because each has a different job to do. Our teeth are also important in helping you talk clearly.
Your teeth have different names depending on their shapes and the jobs they do:
- Incisors at the front of your mouth are flat teeth used for cutting and slicing food. There are four on the top and four on the bottom.
- Canines (cuspids), beside the incisors, are pointed teeth used for tearing food. There are two on the top and two on the bottom.
- Premolars (bicuspids) and molars at the back of your mouth are used for grinding and crushing food.
Amazing Fact: Tremendous force is put on teeth to grind and chew your food. A molar may crush food with as much as 900 pounds per square inch! In comparison, a five-ton elephant standing on one leg would make a force of 120 pounds per square inch on the ground.
- Activity: Using a mirror, find the four kinds of teeth you have. Locate the incisors. Draw a picture of your incisors. Locate your canines and draw a picture. Now find the premolars and molars in the back of your mouth. Draw a picture. How are these teeth alike? How are they different? Make a chart comparing the kinds of teeth.
- Activity: Keep track of which teeth you use in eating a saltine cracker. Take a saltine cracker and eat it slowly. Which teeth bite the cracker? Which teeth chew the cracker? Does the cracker change as you chew it? What happens to the cracker while you are eating it?
- DISCUSS: Incisors bite off bits. Molars chew the cracker. Saliva is mixed with the cracker bits before swallowing. The saliva makes it easier for you to swallow and is the first step in digestion.
- Activity: Upper teeth are attached to bone in the skull, while lower teeth are attached to the jawbone. After cleaning your hands, hold your mouth open by gripping your bottom jaw. Can you close your mouth? When you chew, only your lower jaw moves.
- Activity: List what you have eaten today. Without incisors, which foods would be difficult to eat?
- Activity: You need teeth to speak clearly. Your teeth work with your tongue and lips to make the sounds that make up words. Try saying the word “teeth” without touching your teeth with your tongue. What happens? When you say certain sounds, your tongue presses against your teeth (“th”). In some sounds, you need your upper and lower teeth to make the sound (“c”) or you need your upper teeth and lips (“f”). Say the alphabet slowly and find out which letters need the use of your teeth to say the letter clearly. Make a list of these letters. There are lots of them!