A toolkit in your mouth
Why Do Teeth Have Different Shapes?
Each tooth shape does a different job: cutting, tearing or grinding.
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Step 1 of 5
Food must be broken down before swallowing.
Your stomach can only work on small pieces. Chewing multiplies the surface area so digestion has far more to act on.
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Step 2 of 5
Front teeth are chisels.
You bite an apple with these and nothing else Incisors are flat and sharp-edged, built for slicing straight through. They are what you bite an apple with.
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Step 3 of 5
Pointed teeth grip and tear.
Canines are cone-shaped for holding and tearing tough food. Ours are modest; a dog's are long, because tearing is most of what they do.
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Step 4 of 5
Back teeth are millstones.
Molars are wide and bumpy, and they crush food between two flat surfaces. Most of your chewing happens back there.
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Step 5 of 5
The mix reveals the diet.
Plus eight premolars in between. A grazer has almost no canines at all. Grazers have huge flat molars and no real canines. Big cats have enormous canines and reduced molars. Our balanced set matches a mixed diet.
Enamel is the hardest substance your body makes — and the only one that never repairs itself once damaged.
The short version
Chewing works by multiplying surface area, and three shapes divide the job — chisels at the front, cones for gripping, millstones at the back. A grazer has almost no canines and a big cat few molars, so the mix is the diet.
Try it yourself
Run your tongue along your teeth from front to back. You can feel the shape change from chisel to point to millstone.