Types of teeth

Most people start off adulthood with 32 teeth, not including the wisdom teeth. There are four types of teeth, and each plays an important role in how you eat, drink, and speak.

The different types include:

  • Incisors. These are the chisel-shaped teeth that help you cut up food.
  • Canines. These pointy teeth allow you to tear and grasp food.
  • Premolars. The two points on each premolar help you crush and tear food.
  • Molars. Multiple points on the top surface of these teeth help you chew and grind food.

Read on to learn more about the anatomy and structure of your teeth and conditions that can affect your teeth. We’ll also provide some dental health tips.

Structure and function


The root is the part of the tooth that extends into the bone and holds the tooth in place. It makes up approximately two-thirds of the tooth.

It’s made up of several parts:

  • Root canal. The root canal is a passageway that contains pulp.
  • Cementum. Also called cement, this bone-like material covers the tooth’s root. It’s connected to the periodontal ligament.
  • Periodontal ligament. The periodontal ligament is made of connective tissue and collagen fiber. It contains both nerves and blood vessels. Along with the cementum, the periodontal ligament connects the teeth to the tooth sockets.
  • Nerves and blood vessels. Blood vessels supply the periodontal ligament with nutrients, while nerves help control the amount of force used when you chew.
  • Jaw bone. The jaw bone, also called the alveolar bone, is the bone that contains the tooth sockets and surrounds the teeth’s roots; it holds the teeth in place.


The neck, also called the dental cervix, sits between the crown and root. It forms the line where the cementum (that covers the root) meets the enamel.

It has three main parts:

  • Gums. Gums, also called gingiva, are the fleshy, pink connective tissue that’s attached to the neck of the tooth and the cementum.
  • Pulp. Pulp is the innermost portion of the tooth. It’s made of tiny blood vessels and nerve tissue.
  • Pulp cavity. The pulp cavity, sometimes called the pulp chamber, is the space inside the crown that contains the pulp.


The crown of a tooth is the portion of the tooth that’s visible.

It contains three parts:

  • Anatomical crown. This is the top portion of a tooth. It’s usually the only part of a tooth that you can see.
  • Enamel. This is the outermost layer of a tooth. As the hardest tissue in your body, it helps to protect teeth from bacteria. It also provides strength so your teeth can withstand pressure from chewing.
  • Dentin. Dentin is a layer of mineralized tissue just below the enamel. It extends from the crown down through the neck and root. It protects teeth from heat and cold.

Tooth diagram

Explore the interactive 3-D diagram below to learn more about teeth.

Common tooth conditions

Your teeth perform many functions on a daily basis, which makes them susceptible to a variety of conditions.


Tooth cavities are small holes caused by a buildup of bacteria and acid on the surface of a tooth. Left untreated, they can grow deeper into the tooth, eventually reaching the pulp. Cavities can cause pain, sensitivity to heat and cold, and may lead to infection or tooth loss.


Pulpitis refers to inflammation of the pulp, often due to an untreated cavity. The main symptoms are extreme pain and sensitivity in the affected tooth. It can eventually lead to an infection, causing an abscess in the root of the tooth.

Periodontal disease

Periodontal disease is sometimes called gum disease. It’s an infection of the gums. Common symptoms include red, swollen, bleeding, or receding gums. It can also cause bad breath, pain, sensitivity, and loose teeth. Smoking, certain medications, and poor oral health increase your risk of gum disease.


Malocclusion is the misalignment of teeth. This can cause crowding, underbites, or overbites. It’s often hereditary, but thumb-sucking, long-term use of a pacifier or bottles, impacted or missing teeth, and poorly fitting dental appliances can also cause it. Malocclusion can usually be corrected with braces.


Bruxism refers to grinding or clenching your teeth. People with bruxism are often unaware that they have it, and many people only do it when sleeping. Over time, bruxism can wear down tooth enamel, leading to damage and even tooth loss. It can also cause tooth, jaw, and ear pain. Depending on the severity, it can also damage your jaw and prevent it from opening and closing properly.


A tooth abscess is a pocket of pus caused by a bacterial infection. It can cause tooth pain that radiates to your jaw, ear, or neck. Other symptoms of an abscess include tooth sensitivity, fever, swollen or tender lymph nodes, and swelling in your cheeks or face. See a dentist or doctor right away if you think you have a tooth abscess. Left untreated, the infection can spread to your sinuses or brain.

Tooth erosion

Tooth erosion is the breakdown and loss of enamel caused by acid or friction. Acidic foods and drinks, can cause it. Stomach acid from gastrointestinal conditions, such as acid reflux, can also cause it. In addition, long-term dry mouth can also cause friction, leading to tooth erosion. Common signs of tooth erosion include pain, sensitivity, and discoloration.

Tooth impaction

Tooth impaction happens when there isn’t enough space for a new tooth to emerge, usually due to overcrowding. It’s common in wisdom teeth, but it can also occur when a baby tooth falls out before the permanent tooth is ready to come in.

Symptoms of a tooth condition

Tooth conditions can cause a variety of symptoms, and not all of them are obvious.

Make an appointment with your dentist if you notice any of the following symptoms:

  • tooth pain
  • jaw pain
  • ear pain
  • sensitivity to heat and cold
  • pain trigged by sweet foods and beverages
  • persistent bad breath
  • tender or swollen gums
  • red gums
  • bleeding gums
  • loose teeth
  • discolored teeth
  • fever

Tips for healthy teeth

You can avoid many tooth conditions by taking care of your teeth. Follow these tips to keep your teeth strong and healthy:

  • brush twice daily using a fluoride toothpaste
  • floss between your teeth once a day
  • replace your toothbrush every three months
  • go in for professional dental cleanings every six months
  • limit your intake of sugary foods and drinks
  • if you smoke, talk to your doctor about ways to quit