The Anatomy of a Tooth
By Mina Levi, DDS, 08/13/2015

We all have teeth or have had teeth at some point in our lives, and it is common knowledge that enamel has something to do with the outside of the teeth and can be whitened. However, do you know the anatomy of a tooth inside and out? In this week’s article, San Francisco dentist Mina Levi, DDS breaks down tooth anatomy.

Tooth numbers: The teeth are numbered from 1-32 starting from the upper right side and ending on the lower right side. Tooth #1, 16, 17 and 32 are the wisdom teeth, and some people may not have those in their mouths.

Tooth numbers anatomy San Francisco dentist

The back three larger teeth (Tooth #1-3, 14-16, 17-19 and 30-32) are called molars. The next two teeth that are a little bit smaller than the molars (Tooth #4-5, 12-13, 20-21, and 28-29) are called premolars. The next tooth that is sharp and is often referred to as a fang tooth (Tooth #6, 11, 22, and 27) is called the canine tooth. The rest of the teeth in the very front (Tooth #7-10 and 23-26) are called incisors, central for the very front (Tooth #8, 9, 24 and 25) and lateral for the ones next to them (Tooth #7, 10, 23 and 26).

Quadrants: The mouth and teeth are broken up into four quadrants, upper right (Tooth #1-8), upper left (Tooth #9-16), lower left (Tooth#17-24) and lower right (Tooth #25-32). Each quadrant has 8 teeth: 3 molars, 2 premolars, 1 canine, and 2 incisors (1 central and 1 lateral).

Tooth anatomy Dentist San Francisco

Crown: The crown of the tooth is the part of the tooth that is visible in the mouth and sits on top of the gums.
Root: The roots of the tooth are below the gum line and are the part of the tooth that is cemented into the jawbone. Depending on what type of tooth, there are a different number of roots. For example, a molar generally has 2-3 roots, a premolar has either 1 or 2 roots, and canines and incisors have 1.
Enamel: the enamel is the hardest, white outer part of the tooth that can be seen in the mouth and is made up of calcium phosphate. The enamel helps protect the inside of the teeth from decay.
Dentin: Dentin is the layer underneath the enamel that makes up the general body/filler material of the tooth and is made up on living cells that secrete a hard mineral substance.
Pulp: Pulp is the softer, inner structure of the teeth that hold the nerves and blood vessels in the tooth that run from the jawbone and out of the root canals.

If you have any questions or are interested in the anatomy of the tooth, visit Dentist San Francisco Mina Levi, DDS on the web at or give us a call at (415) 513-5066.