tooth

References & Edit History Quick Facts & Related Topics

Images, Videos & Interactives

A labeled cross section illustration of an adult human molar shows the tooth's crown and root, with layers including enamel, dentin, and pulp, as well as gum, cementum, blood vessels, periodontal ligament, lateral canals, and nerve.

Teeth, primary and permanent

Primary and permanent teeth.

Teeth in vertebrates have been adapted for special uses

The video thumbnail image shows a brown-speckled bird perched on a branch, singing with an open beak.

A dentist holds a glass of water while a child with an exaggerated smile reclines in a dental chair. The water glass is circled, and arrows point to it.

A person holds a piranha from the Napo River in Ecuador, showing its sharp, triangular teeth and red-orange lower jaw as they remove a fishing hook from its mouth.

tooth size comparison: megalodon and modern great white shark

Human body systems interactive

At a Glance

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tooth: Media

anatomy

Videos

The video thumbnail image shows a brown-speckled bird perched on a branch, singing with an open beak.

Why don't birds have teeth?

Birds descended from dinosaurs, but they don't have their ancestors' bite.

Video: Encyclopædia Britannica, Inc.

A dentist holds a glass of water while a child with an exaggerated smile reclines in a dental chair. The water glass is circled, and arrows point to it.

Why is fluoride added to drinking water?

When fluoride goes up, tooth decay goes down.

Video: Encyclopædia Britannica, Inc.

How evolution reveals the differences between humans and apes

How evolution reveals the differences between humans and apes

Learn about human evolution.

Video: Contunico © ZDF Studios GmbH, Mainz; Thumbnail © anne sarfina agustina dimyadi/Dreamstime.com

Images

A labeled cross section illustration of an adult human molar shows the tooth's crown and root, with layers including enamel, dentin, and pulp, as well as gum, cementum, blood vessels, periodontal ligament, lateral canals, and nerve.

An adult molar

Cross section of an adult human molar.

Encyclopædia Britannica, Inc.

Teeth, primary and permanent

Teeth, primary and permanent

Diagram showing human primary and permanent teeth.

Encyclopædia Britannica, Inc.

Primary and permanent teeth.

Primary and permanent teeth.

Humans have two sets of teeth during their lives. The first set consists of 20 primary,...

Encyclopædia Britannica, Inc.

Teeth in vertebrates have been adapted for special uses

Teeth in vertebrates have been adapted for special uses

The sawfish (Pristis), the only animal with true teeth outside its mouth,...

Karl H. Maslowski

A person holds a piranha from the Napo River in Ecuador, showing its sharp, triangular teeth and red-orange lower jaw as they remove a fishing hook from its mouth.

Piranha from the Napo River in Ecuador

© alblec—iStock/Getty Images

tooth size comparison: megalodon and modern great white shark

tooth size comparison: megalodon and modern great white shark

Megalodon (Carcharocles megalodon) tooth (right), significantly larger than...

Jeff Rotman/Alamy

human vocal organs and points of articulation

Diagram depicting the location of human vocal organs and possible places of articulation...

Encyclopædia Britannica, Inc.

Cross section of an adult molar. The crown (the part of the tooth above the gum) is protected by a hard outer layer of enamel. The roots sit in a socket in the jawbone and are covered with cementum, a bonelike material. The periodontal ligament anchors the cementum in the jaw and cushions the tooth from the pressures of chewing. The tooth's main portion, the dentin, surrounds the soft pulp, which carries the blood vessels and nerves. Specialized cells of the pulp project threadlike extensions into the dentin through narrow channels and serve to form new dentin from minerals in the blood.

Cross section of an adult molar. The crown (the part of the tooth above the gum)...

© Merriam-Webster Inc.

Interactives

The Human Body

The Human Body

Experience the major systems of the human body.

Encyclopædia Britannica, Inc.

Human body systems interactive

Human body systems interactive

Interactive diagram of the major systems of the human body.

Encyclopædia Britannica, Inc.

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