Tooth injuries can result in teeth that are chipped, cracked, partially displaced or completely dislodged from the socket in the mouth. These injuries often occur as the result of falls or accidents during athletics.

A tooth injury usually requires a visit to a healthcare professional. In many cases, consulting the dentist is the best option. However, a visit to a hospital emergency room may be necessary if the patient has suffered a blow to the head – which can be life-threatening – or an injury to another body part.

Patients who suffer a tooth injury often have symptoms such as bleeding in the area, pain or increased sensitivity in the tooth. Patients are urged to seek emergency help in cases of dental emergencies, such as when a permanent tooth is knocked out, jaw swelling indicates a potential fracture or bleeding of the gums does not stop despite firm pressure. Appointments with a dentist can be scheduled for less serious injuries, such as a minor chip in a tooth (e.g., cracked teeth).

The severity of injury depends on what portions of the tooth have been damaged. The tooth is composed of several parts:

• Crown. Part of the tooth that is visible above the gum line.
  
  
• Enamel. The hard, translucent outer shell that covers the crown. The enamel is hard enough to handle the strain of a lifetime of biting, chewing and grinding. It also protects the tooth from bacteria and changes in temperature when eating hot or cold foods. Nonetheless, it is very brittle and may crack or chip.
  
  
• Root. Part of the tooth that pushes into the upper (maxilla) or lower (mandible) jawbone. A hard shell called cementum covers the root and attaches to fibers that fasten the root to the jawbone.
  
  
• Dentin. Layer of the tooth found beneath the enamel (protective covering over the crown) and beneath the cementum (protective covering over the root). It makes up most of the tooth’s structure and is responsible for the tooth’s color.
  
  
• Pulp. Located beneath the dentin at the core of the tooth and made up of blood vessels, nerves and connective tissue. The blood supply of the pulp provides the nutrients that keep the tooth alive.

The tooth is also supported by the gums, the pink flesh below the teeth that combine with other features of the mouth to surround and hold teeth in place. Bundles of connective tissue fibers make up the periodontal ligament. These fibers anchor the teeth to the jaws, with one end of each fiber connected to the cementum and the other embedded in the alveolar socket.

Tooth injuries may be described as uncomplicated and complicated. Uncomplicated injuries do not expose the pulp, which reduces the chance of infection and loss of the tooth.

On the other hand, complicated injuries do expose the pulp to potential infection, which can lead to the death of the pulp. If the pulp dies, pus may begin to build up near the root tip in the jawbone. This is called an abscess, and it can damage the bone around the teeth. For this reason, an infected tooth is usually treated with a procedure called a root canal that removes the infected pulp and saves the tooth.

If a permanent tooth is knocked out, rapid action is required to save it. More than 2 million teeth are knocked out each year in mishaps, but 90 percent of them can be saved with proper treatment, according to the National Safety Council. Teeth have the best chance of being saved if they are replaced within 30 minutes of falling out. After two hours, the tooth has a low probability of surviving. For more information, see the section Saving a Tooth.