Impacted tooth

Alternative names:

unemerged tooth; dental impaction; tooth, unemerged

Definition:

A dental disorder involving failure of a tooth to fullyemerge through the gums.

Causes, incidence, and risk factors:

Teeth emerge through the gums during infancy and when theprimary (baby) teeth are replaced by the permanent teeth. If a tooth failsto emerge, or emerges only partially, it is impacted. Because they arethe last teeth to emerge, the most common teeth to become impacted are thewisdom teeth (the third set of molars), which normally emerge between 17and21 years old.

An impacted tooth remains embedded in soft gingiva (gum)tissue or bone beyond its normal eruption time. The cause may be overcrowding,often because the jaw is too small to fit the third set of molars.Teeth may also become twisted, tilted, or displaced as they try to emerge,resulting in impacted teeth.

Impacted wisdom teeth are very common. They are often painlessand cause no trouble; however, in some cases, the impacted tooth pusheson the next tooth and causes it to become misaligned, eventually causingthebite to become shifted. A partially emerged tooth can trap food, plaque,and other debris in the soft tissue around it; leading to inflammation andtenderness of the gums and unpleasant mouth odor. This is calledpericoronitis.

Prevention:

There is no known prevention.

Symptoms:

* pain or tenderness of the gums (gingiva)

* unpleasant taste when biting down on or near thearea

* visible gap where a tooth did not emerge

* bad breath

* redness and swelling of the gums around the impactedtooth

* swollen lymph nodes of the neck (occasionally)

* difficulty opening the mouth (occasionally)

* prolonged headache or jaw ache

Signs and tests:

Examination of the teeth by the dentist may show enlargementof the tissue over the area where a tooth has not emerged, or has emergedonly partially. The impacted tooth may be pressing on adjacent teeth. Thegums around the area may show signs of infection (such as redness, drainage,and tenderness). As gums swell over impacted wisdom teeth andthen drain and tighten, it may feel like the tooth came in and then wentback down again.

Dental X-rays confirm the presence of a tooth (or teeth)that has not emerged.

Treatment:

The goal of treatment is to relieve irritation of the mouthcaused by the impacted tooth. If the impacted tooth is not causing infectionor inflammation, or is not affecting the alignment of the otherteeth, no treatment may be necessary.

Over-the-counter analgesics may relieve discomfort. Warmsalt water(one-half teaspoon of salt in one cup of water) orover-the-counter mouthwashes may be soothing to the gums.

Extraction (removal) of the tooth is the usual treatmentfor symptomatic impacted tooth. This often is performed in the dentist'soffice under local anesthesia. If the tooth is deeply impacted or difficultywith extraction is expected, the dentist may refer the person to an oralsurgeonfor tooth removal. Antibiotics may be required prior to tooth extractionif the area around the tooth is infected.

Expectations (prognosis):

Impacted teeth may cause no problems for some people andmay never require treatment. If the impacted tooth is causing symptoms,treatment,including extraction, is usually successful in resolving thesymptoms.

Complications:

* recurrent infection of a partially buried tooth

* abscess of the tooth/gums

* malocclusion of the teeth

* chronic discomfort in the mouth

* "dry socket" once the tooth has been removed

Calling your health care provider:

Call your dentist if there is an unemerged tooth (or partiallyemerged tooth) and pain in the gums or other symptoms havedeveloped.

Dr. Song's Oral Medicine Forum