Teeth: Types, Structure & Function

Instructor: Jennifer Preuss

Jen has practiced for 15 years in the healthcare field and has a Master's Degree in Education.

In this lesson, you will learn about all of the different types of teeth in your mouth. You will also learn about the function of each type of tooth, and how the structure of the tooth helps aid in its function.

Say Cheese!

You're brushing your teeth in front of your bathroom mirror and you start to look closely at each tooth. You notice that each one looks different. Some are wide and flat, some are pointed, and some have bumps on them. Before now, you thought maybe they all just looked alike. Before you panic and wonder why your teeth look so different from each other, let's talk about why each tooth looks different and how each tooth in your mouth has a different function to help you bite, tear, chew and grind your food.

Overview of Teeth

In your lifetime, you will have two sets of teeth, also known as dentition. The first set, known as primary teeth, are your baby teeth. Typically, a person will have a total of 20 baby teeth, which start erupting into the mouth around four to six months old and are all in the mouth by about age three.

Around age five or six, the baby teeth start to get loose and fall out, and the next set of teeth start to erupt in the mouth. This set of teeth is called permanent teeth, or the permanent dentition. There are a total of 32 permanent, or adult, teeth that should erupt in the the mouth. Three different types of teeth make up the primary dentition, and four types make up the permanent dentition.

The structure of each tooth is made up of the crown and the root of the tooth. The crown is the part of the tooth that you can see when you look in your mouth, and the root is the part of the tooth that is underneath your gums. The root serves as the anchor that holds your tooth in your jawbone.

Types of Teeth


The first type of tooth in your mouth is called the incisor. Incisors are the teeth that you mostly see when you smile. You have eight incisors in your mouth: four on the top and four on the bottom. Incisors are flat on the front and have a wide, sharp chewing surface so that you can cut or shear your food.


Canines are the teeth that are at the corners of the mouth. Many people think that these teeth resemble fangs. There are four canines: two on the top and two on the bottom. Canines are pointed on the chewing surface in order to tear food.


Premolars are the teeth beside the canines. Premolars are only present in the permanent dentition. There are eight premolars: four on top and four on the bottom. They have a flatter chewing surface so that they can crush and chew your food.

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