Structure: Teeth and Gums

Teeth vary in shape and size but have an identical structure. Each tooth consists of a hard shell that surrounds a cavity of soft tissue, known as pulp. The crown (the exposed part of the shell) is coated in a tough layer of enamel, beneath which is a layer of a yellowish substance similar to ivory, called dentine. The dentine and pulp form long, pointed roots that extend into the jawbone and are covered by a layer of firm, fleshy tissue called the gums.

Side view of the jaws and teeth


The sharp chisel-like incisors, situated at the front of the mouth, cut and hold food.


Canines are longer and more pointed than incisors; they are used for tearing food.


Premolars have two prominences (cusps) on their biting surfaces and are used for grinding food.


Molars, the largest teeth, are used for grinding. They have four or five cusps on their chewing surfaces.

The upper surface of a molar

This magnified image shows the normal undulations on the chewing surface of a molar tooth.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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