Hossein Ghaeminia, Marloes EL Nienhuijs, Verena Toedtling, John Perry, Marcia Tummers, Theo JM Hoppenreijs, Wil JM Van der Sanden, Theodorus G Mettes
We carried out this review, through Cochrane Oral Health, 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.
Wisdom teeth (also known as third molars) generally erupt between the ages of 17 and 26 years. They are the last teeth to come in, and normally erupt into a position closely behind the last standing teeth (second molars). Space for wisdom teeth can be limited and so they often fail to erupt or erupt only partially, because of impaction of the wisdom teeth against the teeth directly in front. In most cases, this occurs when second molars are blocking the path of eruption of third molar teeth and act as a physical barrier, preventing complete eruption. An impacted wisdom tooth is called 'asymptomatic' and 'disease‐free' if there are no signs or symptoms of disease affecting the wisdom tooth or nearby structures.
Impacted wisdom teeth can cause swelling and ulceration of the gums around the wisdom teeth, damage to the roots of second molars, decay in second molars, gum and bone disease around second molars and development of cysts or tumours. It is generally agreed that removing wisdom teeth is appropriate if signs or symptoms of disease related to the wisdom teeth are present, but there is less agreement about how asymptomatic disease‐free impacted wisdom teeth should be managed.
The Cochrane Oral Health Information Specialist searched the medical literature up to 10 May 2019. We found two studies, one where the participants had been randomly chosen to have their wisdom teeth removed or not (a randomised controlled trial or RCT), and one where the study authors examined people who have opted themselves to either retain or remove their wisdom teeth (a prospective cohort study). 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 volunteered to take part.
The available evidence is insufficient 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 (the cohort study), which was at serious risk of bias, found that keeping asymptomatic disease‐free impacted wisdom teeth in the mouth may increase the risk of gum infection (periodontitis) affecting the adjacent second molar in the long term, but this evidence was very uncertain. In the same study, the evidence was insufficient to draw any conclusions about the effect on the risk of caries in the adjacent second molar.
The other study (the RCT) 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.
Quality of 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.
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.
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.