This site complies with the HONcode standard for trustworthy health information:
verify here.

Rewarding for
you and us
Defeat Diabetes Foundation

Defeat Diabetes
Foundation
150 153rd Ave,
Suite 300
Madeira Beach, FL 33708

Anatomy of a Tooth

October is National Dental Hygiene month, so let’s focus a bit on a part of our bodies many of us take for granted: our teeth.

Not only do our teeth allow us to chew and eat they also help form the shape of our face. In addition, teeth help you to speak clearly. Many letters of the alphabet cannot be sounded without the help of teeth. Clean, healthy teeth help you look good and contribute to your total body health and well-being. And, a smile always helps you look your best.

Teeth have different shapes for different jobs. The names of these teeth are:

Incisors -- there are eight incisors located in the front of the mouth (four on the top and four on the bottom). They have chisel-shaped crowns that cut food. Incisors are used to cut food. An incisor has 1 root.

Cuspids -- the four cuspids are next (to) each incisor (2 in the top jaw and 2 in the bottom jaw). Cuspids are also sometimes called canines and have a pointed edge to hold and tear food and have a single root.

Premolars – these are also called bicuspids, or first molars. Adults have 8 premolars (4 in the top jaw and 4 in the bottom jaw) and are located next to the cuspids. They crush and tear food. Bicuspids have two points (cusps) at the top.

Molars -- there are twelve molars, in sets of three, at the back of the mouth. They have wide surfaces that help to grind food. Molars in the top jaw have 3 roots; molars in the lower jaw have 2 roots.

People have two sets of teeth in their lives. The first set, or primary teeth (also called the baby, milk or deciduous teeth) begin erupting from about six months of age. Children have 20 primary teeth and oral hygiene is just as important for children as it is for adults. The permanent teeth, also called the adult or secondary teeth, are generally erupted by age 13 (though, wisdom teeth [third molars] can come in between ages 17 – 30.)

Let’s take a brief look at the anatomy of our teeth. Our teeth can be sub-divided into the parts above the gum line and those below the gum line.

The gums are the soft tissue that surrounds the base of the teeth.

The part of the tooth you see in your mouth is called the crown. The hard white outer covering of the tooth is the enamel.

The enamel is the part of the tooth that gets decayed. The rounded high parts of the back teeth are cusps.

Below the gum line, is the root of the tooth and this, in conjunction with the periodontal membrane/ligament, is what holds the tooth into the jawbone. The number of roots ranges from one to four depending on the tooth.

The periodontal membrane/ligament is the fleshy tissue between the tooth and the tooth socket. The fibers of the periodontal membrane are embedded within the cementum.

The tooth itself also has an inner anatomy that you can’t see. The inner portions of the tooth consist of: the cementum, which is a layer of tough, yellowish, bone-like tissue that covers the root of a tooth. It helps hold the tooth in the socket. Dentin is as hard as bone but is a porous tissue located under both the enamel and cementum of the tooth. The pulp contains the nerves and blood vessels at the center of the crown and root, and nourishes the dentin. The nerves transmit signals (conveying messages like hot, cold, or pain) to and from the brain.

Updated 2010