Definition

An impacted tooth is a tooth that is positioned against another tooth, bone, or soft tissue so that it is unlikely to fully erupt through the gums to reach its normal position in the mouth.

Causes

Impaction typically occurs in the third molars, also called the wisdom teeth. Wisdom teeth, which begin to develop around age 9, are most vulnerable to impaction because they are the last teeth to erupt, usually between the late teens and early 20s. By then, the jaw has stopped growing and may be too small to accommodate these 4 teeth.

An impacted tooth remains embedded in soft gum tissue or bone beyond its normal eruption time. The cause may be overcrowding. Other teeth may also become twisted, tilted, or displaced as the new teeth try to emerge.

Risk Factors

Impacted teeth are common. Factors that may increase your risk of impacted teeth include:

• Genetics
• Poor orthodontic treatment

Symptoms

Some people with impacted teeth have no pain or other symptoms. In those who have symptoms, impacted teeth may cause:

• Pain or tenderness of the gums or jaw bone
• Unpleasant taste when biting down
• Bad breath
• Redness and swelling of the gums around the impacted tooth
• Prolonged, unexplained headache or jaw ache
• Difficulty opening your mouth

Complications of untreated impacted teeth include:

• A cyst in the soft tissue under the gum line
• Tooth decay
• Misalignment of other teeth
• Inflammation of the gums, which can lead to infection—gingivitis
• Absorption of bone or adjacent teeth

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. Tests may include:

• A visual examination to look for signs of infection or swelling
• Dental x-rays to confirm tooth impaction

Treatment

If an impacted tooth causes no pain, inflammation, or infection, and does not affect mouth alignment, no treatment may be necessary.

If there are noticeable symptoms, surgery is usually recommended to remove all impacted teeth, preferably while the person is young. This may be done by a dentist under local anesthesia if the tooth is exposed and can be easily removed in one piece. For difficult extractions, your dentist may refer you to an oral surgeon. In these cases, general anesthesia or an IV sedative may be used. Your dentist may recommend following until surgery can be scheduled:

• Over-the-counter pain relievers to ease pain and swelling
• Gargling with warm salt water to soothe gums

Prevention

There are no current guidelines to prevent impacted teeth.

Mouth Healthy—The American Dental Association http://www.mouthhealthy.org

Canadian Dental Hygienists Association http://www.cdha.ca

Wisdom teeth. American Dental Association Mouth Healthy website. Available at:
http://www.mouthhealthy.org/en/az-topics/w/wisdom-teeth
Accessed August 10, 2015.

Wisdom teeth management. American Association of Oral and Maxillofacial Surgeons website. Available at:
http://myoms.org/procedures/wisdom-teeth-management
Accessed August 10, 2015.