Different Teeth Types and Their Functions – (Incisors, Canines, Premolars, and Molars)

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Your teeth are unique to you. The shape, form, and bite of human teeth are specific to each individual.

Different Teeth Types and Their Functions

While the teeth are the hardest tissue found in the body, it is crucial to take care of your teeth to prevent diseases.

Your upper and lower jaws are lined with different sets of teeth that change as you grow.

The first set of teeth that you receive are your baby teeth. These teeth fall out when the right time arises, making way for a new set of teeth to erupt. These are your adult teeth.

Once your adult teeth erupt, they take the places of their predecessors. Most adults have 32 teeth; each of these 32 teeth serves a specific function.

Learn more about the different types of permanent teeth and why dentists urge you to take proper care of each one.

Introduction to Dental Diversity

Unlike your heart or brain, your teeth aren’t ready to function immediately when you’re born. 

Instead, your first teeth gradually begin to erupt between 4 months and 12 months. Each child has 20 primary teeth, also called milk teeth or baby teeth. By 6 years, kids usually have all 20 of them in place.

When the child turns 6, these milk teeth start falling out to make room for the permanent teeth to erupt. Most adults have 32 permanent teeth, however, some may be born with missing teeth (hypodontia) or extra teeth (hyperdontia).

Your last molar teeth are called wisdom teeth. Since, on average, the human mouth has adequate space for only 28 permanent teeth, these wisdom teeth usually come in abnormally. In cases where they cannot erupt properly due to lack of space, they are extracted.

The Tooth Anatomy

Before we explore the different types of teeth in an adult human’s mouth, let’s take a tour of the parts that make up a tooth.

The Tooth Anatomy

Generally speaking, a tooth is divided into two parts – the crown, the visible portion of the tooth, and the root, the portion of the tooth that is embedded under your gums. The root helps anchor your tooth to the periodontal ligament which helps keep your tooth in place.

Each of your teeth is made up of four layers, namely:

  • Enamel: This is the outer protective layer of the tooth that gives it that white, shiny appearance you see. It is tough, so it acts as a barrier to shield the inside layers from harmful bacteria and damage.
  • Dentin: If you were to peel away the enamel, you’d find a softer and yellower layer called the dentin. This layer provides a protective casing to the innermost layer and supports the enamel.
  • Pulp: This is the innermost part of the tooth that contains the tooth’s nerve endings, blood supply, and connective tissues. The pulp helps feed the tooth to keep it alive and healthy.
  • Cementum: The cementum makes up only the roots of the tooth. Along with the periodontal fibers, it helps anchor the tooth to the jawbone.

Understanding the Importance of Different Types of Teeth

Humans have different types of teeth to help cut, tear, and grind food into digestible pieces. The teeth in your upper and lower jaw are supported by your jaw muscles while performing these motions. 

Once the food is reduced into smaller parts, the saliva helps lubricate the food to be swallowed by your throat muscles.

Four Types of Teeth

We possess teeth that vary in structure and numbers. The number of teeth present in half of your upper jaw and half of your lower jaw is expressed in a formula called the dental formula. 

For adult humans, the dental formula is 21232123, which translates to 2 incisors, 1 canine, 2 premolars, and 3 molar teeth on each side of the arch.

Different teeth have different teeth names. In total, including wisdom teeth, we have five varieties of teeth. 

The five different types of teeth include:

Incisors

The first types of teeth are incisors. These are your two front teeth that your friends and family see when you greet them with a smile. There are two types of incisors – central and lateral incisors.

Central Incisors

Central incisors are the middle two teeth. The upper incisors are shaped like shovels and are positioned in the most prominent area of the mouth. The lower centrals are flat and thin. They typically only have one root. 

The primary function of the centrals is to cut food into small pieces. For instance, when you take a bite of an apple, these two upper incisors are responsible for biting into the apple and slicing it with their sharp edges.

The lower centrals are typically one of the first permanent teeth to come in after the exfoliation of the baby teeth between the ages of 6 and 7 years. Adults have four permanent central incisors.

Lateral Incisors

The lateral incisors are the two small teeth that are next to your central incisor teeth. They resemble the centrals but are smaller in dimension. Much like the centrals, they also have a single root.

They play a vital role in digestion, as they cut the food into smaller pieces during chewing. The lateral incisors are also the most common tooth that can be congenitally missing in some individuals.

Permanent laterals erupt at ages between 7 and 8 years. Adults have four lateral incisors, two in the upper jaw (maxilla) and two in the lower jaw (mandible).

Canines

The second type of teeth is the canine teeth. They are present on either side of the incisors and form the cornerstones of the mouth. They are the sharpest teeth, the upper usually being longer and larger than the lower.

Four Types of Teeth

These pointed teeth are the strongest type of all teeth varieties and are highly resistant to immense pressure caused during chewing. The canine teeth help shear the food and also support the lips as they make up the natural curve of the dental arch.

Canines also play an important role in supporting your maxilla and mandible when it grinds from side to side. 

In an ideal dentition, the canines support the dentition in sideways movement so that none of the back teeth or teeth on opposite sides need to come in contact. This helps prevent wear and fractures to the back teeth. 

Adults have four canine teeth in their mouths. These come in by the time the kid turns 9 to 10 years old. They have only one root. The incisors and canines together are known as the cuspids as they only have one sharp edge to their crowns.

Premolars

Just next to the canine teeth are your premolar teeth. Adults typically have two premolars – the first and second premolars in one half of an arch. In total, adults have eight premolars in their mouths – four on the bottom and four on the top arch.

Premolars have two cusps and are therefore called bicuspids. They are flat on top and are used to chew and grind food into smaller pieces when chewing. 

Premolars also help maintain the height of your face. Additionally, they are the most common teeth that are extracted when needed during orthodontic treatment to maintain symmetry and proper dental occlusion in patients.

The premolar teeth are located between the canines and the molar teeth. Since premolars are absent in the primary dentition, they usually erupt in the place previously occupied by primary molars. They erupt anywhere between ten and twelve years of age.

Molars

The molars are the large, flat teeth found at the back of the mouth. Generally, adults have three types of molars, the first, second, and third molars on each side of their jaw.

In total, adults have 12 molars. Excluding the third molars, you will typically have four in the upper jaw and four in the lower one.

Molar teeth have four or five cusps that help grind food. The first permanent molars erupt behind the primary second molars at age 6 years. The second molar may erupt only when the child turns 12 years old or even later.

Third molars

The third molar, commonly known as wisdom teeth is the last tooth to erupt and is found in the rearmost region of the jaw.

Wisdom Teeth

Typically you can have four wisdom teeth in total, however, most may not erupt properly due to the lack of adequate space at the back of the jaw.

When these teeth become impacted and are unable to break through the gum, they may be removed. If you get your wisdom teeth removed, you will only have 28 permanent teeth. 

The wisdom teeth are the last teeth to erupt, with some erupting at age 20 or later. However, some individuals may be missing their third molars.

Takeaway

Now that you understand the different teeth types, you should strive to keep them healthy and get regular checkups at your local dental office. Your teeth play a fundamental role in the digestion and absorption process. 

Humans eat food throughout their lives. Hence, it is important to preserve your valuable chompers to keep them on for longer.

If your teeth are chipped or decayed, or if your teeth have come in abnormally, you should visit your dentist to get a routine assessment.

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