Teeth

Cut, tear and grind food. Enamel is the hardest substance the body produces, harder than steel by indentation, but it contains no living cells and cannot regenerate once lost.

The numbers

Adult teeth

32, including 4 wisdom teeth

Primary teeth

20

Enamel hardness

5 Mohs

Types

8 incisors, 4 canines, 8 premolars, 12 molars

Worth knowing

Enamel is the only tissue in the body that cannot repair itself, because it contains no cells — every cavity is permanent damage that has to be filled rather than healed. Wisdom teeth are vestigial third molars, and a substantial minority of people never develop some or all of them.

Structural reference only — this is not medical advice, and individual variation in every figure here is substantial. Anything concerning your own health belongs with a clinician rather than a reference page.