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A toolkit in your mouth

Why Do Teeth Have Different Shapes?

Each tooth shape does a different job: cutting, tearing or grinding.

Front teeth: chiselsfor cuttingPointed teeth: forgripping and tearingBack teeth: flatmillstones for grinding
Three tools, one mouth.

  1. Step 1 of 5

    Food must be broken down before swallowing.

    1 A big piece offood2 Chewed intofragments3 Far moresurface fordigestion

    Your stomach can only work on small pieces. Chewing multiplies the surface area so digestion has far more to act on.

  2. Step 2 of 5

    Front teeth are chisels.

    Incisors Flat, sharp — forcuttingMolars Broad, flat — forgrinding

    Incisors are flat and sharp-edged, built for slicing straight through. They are what you bite an apple with.

  3. Step 3 of 5

    Pointed teeth grip and tear.

    Human canines Small — we mostly grindDog canines Long — for gripping andtearing

    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.

  4. Step 4 of 5

    Back teeth are millstones.

    A molar A broad ridged surfacefor crushing

    Molars are wide and bumpy, and they crush food between two flat surfaces. Most of your chewing happens back there.

  5. Step 5 of 5

    The mix reveals the diet.

    Grass eater All grinding surfaceMeat eater All tearing points

    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

Teeth have different shapes because cutting, tearing and grinding are different jobs, and the mix reveals 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.

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