Wisdom teeth generally grow and appear between the ages of 17 and 26 years. They are the last teeth to come through and normally grow into a position close to other teeth. Space for wisdom teeth can be limited and so they often fail to come through, or only partly come through. In most cases, this occurs when other teeth are blocking the growth of wisdom teeth, and act as a barrier. A wisdom tooth like this is known as an “impacted tooth”. An impacted wisdom tooth is called ‘asymptomatic’ and ‘disease‐free’ if there are no signs of disease affecting the wisdom tooth or the gum which supports it.
Impacted wisdom teeth can cause swelling and soreness of the gums around the wisdom teeth and decay and damage to nearby teeth. They can also cause gum and bone disease around other teeth and the development of cysts or tumours. It is generally agreed that wisdom teeth should be removed if there are signs of disease, but there is less agreement about how to manage wisdom teeth if there are no signs of disease.
What was the research?
A systematic review to find out whether impacted wisdom teeth in teenagers or adults should be removed if they are not causing any problems or they should be left alone and checked at regular intervals. This is an update of a review first published in 2012 and first updated in 2016.
Who conducted the research?
The research was conducted by a team led by Hossein Ghaeminia from Rijnstate Hospital Arnhem, Arnhem, The Netherlands on behalf of Cochrane Oral Health. Marloes EL Nienhuijs, Verena Toedtling, John Perry, Marcia Tummers, Theo JM Hoppenreijs, Wil JM Van der Sanden and Theodorus G Mettes were also on the team.
What evidence was included in the review?
The Cochrane Oral Health Information Specialist searched the medical literature up to 10 May 2019. We found one randomised controlled trial (RCT), where the participants had been randomly chosen to have their wisdom teeth removed or not. We also included one study where the study authors examined people who have opted themselves to either retain or remove their wisdom teeth. The studies involved 493 people. The RCT was conducted at a dental hospital in the UK and included 77 adolescent male and female participants who had completed treatment with braces. The cohort study was conducted at a private dental clinic in the USA and involved 416 men aged 24 to 84 years who had volunteered to take part.
What did the evidence say?
There is not enough high-quality evidence to tell us whether or not asymptomatic disease‐free impacted wisdom teeth should be removed.
The included studies did not measure health‐related quality of life, costs, or side effects of taking teeth out.
One study found that keeping asymptomatic disease‐free impacted wisdom teeth in the mouth may increase the risk of gum infection affecting the nearby teeth in the long term. However, this evidence very uncertain due to the study being at high risk of bias.
The other study was also at high risk of bias. It measured crowding of the teeth in the mouth and found that this may not be significantly affected by whether impacted wisdom teeth are kept in the mouth or removed.
How good was the evidence?
We assessed the evidence provided by the two studies to be low to very low certainty, so we cannot rely on these findings. High‐quality research is urgently needed to support clinical practice in this area.
What are the implications for dentists and the general public?
There is a lack of scientific evidence on which dental health professionals and policy makers can base treatment decisions for asymptomatic disease‐free impacted wisdom teeth. Dental professionals will therefore be guided by clinical expertise and local or national clinical guidance, taking patient preferences into account. Where asymptomatic disease‐free impacted wisdom teeth are not removed, monitoring by a dental health professional at regular intervals will help identify and address any problems that may develop.
What should researchers look at in the future?
Long‐term, well‐designed studies comparing removal or retention of asymptomatic disease‐free impacted wisdom teeth are urgently needed.
Link
Ghaeminia H, Nienhuijs MEL, Toedtling V, Perry J, Tummers M, Hoppenreijs TJM, Van der Sanden WJM, Mettes TG. Surgical removal versus retention for the management of asymptomatic disease‐free impacted wisdom teeth. Cochrane Database of Systematic Reviews 2020, Issue 5. Art. No.: CD003879. DOI: 10.1002/14651858.CD003879.pub5.
This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health Editorial Base.
Cochrane Oral Health 