Tooth anatomy

What do you know about your teeth?

For many, the knowledge about their teeth is limited.

  • We know that our teeth are useful to eat, that they influence our look and that we must take care of them.
  • We know that our teeth are “replaced” (primary dentition) during childhood and that some will be weakened at an advanced age.
  • We also know that our teeth can be a source of discomfort, pain, and worries and that a better knowledge of this component of our body is desirable.

So, what is a tooth? What is its composition?

The structure of a tooth is similar to an apple

In a very simplified way, the general structure of a tooth is similar to that of an apple.

Like a peel, enamel covers and protects the visible part of the tooth.

Dentin is the second layer of the tooth. Like the flesh of the apple, this material takes up the largest volume of the tooth. Although its strength is lower than that of enamel, it remains as tough as a human bone. Dentin is the last “armor” protecting the life of the tooth because it offers protection to its central part. Once attacked by decay, the dentin deteriorates very quickly.

Dental pulp (the nerve of the tooth) is the equivalent of the heart of the apple. Located in the center of the tooth, the pulp is composed of tiny blood vessels and nerves, making the tooth sensitive to pain.

Tooth anatomy

The tooth consists of two main sections: the root and crown.

Root

The part hidden below the gum line is the root. This part of the tooth is embedded in the bone of the jaw. Like the posts of a fence, roots firmly keep teeth in position. The number of roots varies from one tooth to another: the anterior teeth (front teeth) have one root while premolars and molars have two or three roots for resisting the pressure exerted on them when chewing.

Crown

The crown is the visible part of the tooth located above the gum, which comes into contact with food.

Surfaces

The crown of the tooth has 5 distinct surfaces:

The mesial surface;
The distal surface;
The buccal surface;
The lingual surface;
The occlusal surface (molars). For teeth that do not have a chewing surface (teeth at the front of the mouth), this surface is called the Incisal.

Nomenclature of teeth

Our teeth are classified into 5 categories:

  • The 4 central incisors: located directly under the nose (2 at the top, 2 at the bottom). The upper ones are sometimes called « rabbit teeth » or « pallets ».
  • The 4 lateral incisors: adjacent to the central incisors (2 at the top, 2 at the bottom).
  • The 4 canines (« fangs »): the most pointed and each one has only one long root (2 at the top, 2 at the bottom).
  • The 8 premolars: are used to chew (4 at the top, 4 at the bottom).
  • The 12 molars: resistant to high pressures and positioned at the back (6 at the top, 6 at the bottom). We find the first, second and third molars (wisdom teeth).

The 12 teeth located at the front of our mouth (incisors and canines) are called anterior teeth. They allow tearing and cutting. These are the teeth that are visible when we smile. The other 20 teeth (premolar and molar) positioned towards the back of the mouth are called posterior teeth. They have an occlusal surface that allows them to chew and crush food.