The Anatomy of a Tooth

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Have you ever wondered what your teeth look like on the inside? They might look hard and white, but beneath the surface is a fascinating world. Below we look at the anatomy of a tooth, and explore the different types of teeth you have in your mouth.

The Four Dental Tissues

Teeth contain four key dental tissues. Enamel, cementum and dentin are hard tissues, while the fourth, pulp, is a soft tissue.

Enamel is the hard calcified tissue in the crown of the tooth, which covers the dentin. Enamel cannot repair any decay or damage caused by wear and tear, because it does not contain any living cells.

Cementum is the hard connective tissue which covers the root of the tooth, providing an attachment to the periodontal ligament.

Dentin is found beneath the enamel and cementum. Dentin contains microscopic canals and tubes. When enamel is lost and the dentin is exposed, these canals and tubes allow hot and cold foods to stimulate nerves inside the tooth. This is the cause of sensitive teeth.

Pulp is contained within the very centre of the tooth. This soft material contains connective tissue, blood vessels and nerves.

Other Parts of the Tooth

The crown is the part of the tooth which is visible in your mouth. It will normally be covered in enamel.

The gums (gingiva) are the soft tissues which protect and cover the roots of the tooth, and also cover teeth which have not yet erupted into the mouth.

The root canal is the space within the root which contains pulp.

Types of Teeth

There are four types of teeth inside your mouth and each performs a certain function.

Incisors – At the front of your mouth are eight straight, thin teeth known as incisors. There are four at the top and four at the bottom. These teeth are used to bite into food, to support the lips and to help with the pronunciation of words when you speak.

Canines – On each side of the top and bottom sets of incisors is a single canine tooth. These pointy teeth are used for biting and tearing food and also help to support your lips. The canine teeth also act as a guide to bring your teeth into line when you close your mouth.

Premolars – Behind the canines, running towards the rear of the mouth are the premolar teeth. Premolars are flat on top and are used for chewing food. There are normally a total of eight premolars, four on the top and four on the bottom of the jaw.

Molars – Finally, at the very rear of the mouth are the molars. These are the widest and flattest of all the teeth. There are normally 12 molars in an adult mouth, with six at the top and six at the bottom.

Supernumerary Teeth

While the normal adult mouth contains 32 teeth, sometimes extra teeth can develop in the mouth. These supernumerary teeth do not always cause problems, but if they are crowding the mouth they may need to be removed by a dentist.