Surgical removal versus retention for the management of asymptomatic impacted wisdom teeth

Wisdom teeth, or third molars, generally erupt into the mouth between the ages of 17 to 24 years. These are normally the last teeth to erupt and mostly into a position closely behind the last standing teeth (second molars). Space for these teeth to erupt can be limited and more than other teeth, wisdom teeth often fail to erupt or erupt only partially. Failure of the third molars to fully erupt is often due to impaction of the wisdom teeth against the second molars (teeth directly in front of the wisdom teeth). This occurs when the second molars are blocking the path of eruption of the third molar teeth and act as a physical barrier preventing further eruption. An impacted wisdom tooth is called asymptomatic if the patient does not experience signs or symptoms of pain or discomfort associated with this tooth.

Impacted wisdom teeth may be associated with pathological changes, such as swelling and ulceration of the gums around the wisdom teeth, damage to the roots of the second molars, decay in the second molars, gum and bone disease around the second molars and the development of cysts or tumours. General agreement exists that removal of wisdom teeth is appropriate if symptoms of pain or pathological conditions related to the wisdom teeth are present. This review found no evidence to support or refute routine prophylactic removal of asymptomatic impacted wisdom teeth in adults. The only included trial provided no evidence that removal of impacted wisdom teeth has an effect on late crowding of front teeth.

Authors' conclusions: 

Insufficient evidence was found to support or refute routine prophylactic removal of asymptomatic impacted wisdom teeth in adults. A single trial comparing removal versus retention found no evidence of a difference on late lower incisor crowding at 5 years, however no other relevant outcomes were measured.

Watchful monitoring of asymptomatic third molar teeth may be a more prudent strategy.

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Background: 

The prophylactic removal of asymptomatic impacted wisdom teeth is defined as the (surgical) removal of wisdom teeth in the absence of local disease. Impacted wisdom teeth may be associated with pathological changes, such as inflammation of the gums around the tooth, root resorption, gum and alveolar bone disease, damage to the adjacent teeth and the development of cysts and tumours. Other reasons to justify prophylactic removal have been to prevent late incisor crowding. When surgical removal is carried out in older patients, following the development of symptoms, the risk of postoperative complications, pain and discomfort increases. Nevertheless, in most developed countries prophylactic removal of trouble-free wisdom teeth, either impacted or fully erupted, has long been considered as 'appropriate care' and is a very common procedure. There is a need to determine whether there is evidence to support this practice.

Objectives: 

To evaluate the effects of prophylactic removal of asymptomatic impacted wisdom teeth in adolescents and adults compared with the retention (conservative management) of these wisdom teeth.

Search strategy: 

The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 30 March 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1950 to 30 March 2012), and EMBASE via OVID (1980 to 30 March 2012). There were no restrictions on language or date of publication.

Selection criteria: 

All randomised controlled trials (RCTs) on adolescents and adults comparing the effect of prophylactic removal of asymptomatic impacted wisdom teeth with no-treatment (retention).

Data collection and analysis: 

Six review authors screened the results of the search and assessed whether trials met the inclusion criteria for the review. Data extraction and risk of bias assessment were conducted in duplicate and independently by six review authors. Where information was unclear, authors of studies were contacted for additional information.

Main results: 

No RCTs were identified that compared the removal of asymptomatic wisdom teeth with retention and reported quality of life. One RCT on adolescents was identified that compared the removal of impacted mandibular wisdom teeth with retention and only examined the effect on late lower incisor crowding. This study at high risk of bias provided no evidence that extraction of wisdom teeth had an effect on lower incisor crowding over 5 years.