There is no evidence to support prophylactic removal of disease-free impacted third molars
- Hicks, E. Preston DDS, MS, MSD
OBJECTIVE
To summarise existing evidence of the incidence of surgical complications associated with prophylactic removal of disease-free impacted third molars, and the morbidity associated with retention.
METHOD
Systematic review of randomised controlled trials.
LITERATURE REVIEW
Searches of six electronic databases. Relevant organisations and professional bodies were contacted for further information. There were no language restrictions.
INCLUSION AND EXCLUSION CRITERIA
Randomised controlled trials, literature reviews, or decision analyses were included if participants were people with unerupted or impacted third molars, or if they were undergoing surgical removal of third molars either as prophylaxis or due to associated pathological changes. Studies had to report either the pathological changes associated with retention of third molars, or post-operative complications following extraction.
DATA EXTRACTION AND SYNTHESIS
Decisions relating to study selection, data extraction and validity assessment were made by two independent reviewers, and disagreements were resolved by discussion. For non-English papers, translators were recruited to assist with study selection and data extraction. The main method of analysis was qualitative. Forty studies were included in the review: two randomised controlled trials, 34 literature reviews, and four decision analysis studies.
MAIN RESULTS
The methodological quality of the literature reviews was generally poor. The decision analyses consistently suggested that retention of third molars was more cost-effective compared with prophylactic removal of impacted third molars. One randomised controlled trial in the UK focused on the effects of retained third molars on incisor crowding (predominantly a cosmetic problem) in patients who had previously undergone orthodontic treatment. This trial suggested that the removal of third molars to prevent late incisor crowding cannot be justified. Another on-going randomised controlled trial in Denmark compares the effects and costs of prophylactic removal of third molars with removal according to morbidity. So far, this trial has recruited 200 participants, and preliminary results indicate that watchful waiting may be a promising strategy. However, more data and longer follow-up of patients are needed to conclude as to which treatment strategy is the most cost-effective.
AUTHORS' CONCLUSIONS
There is no reliable research evidence to support the pro phylactic removal of disease-free impacted third molars. Available evidence suggests that retention may be more effective and cost-effective than prophylactic removal, at least in the short-to-medium term.
ABSTRACTOR'S COMMENTS
This is a well conducted systematic review. The main limitation is the quality of the research on effectiveness from which to draw conclusions which inevitably impacts on cost-effectiveness assessments. The tentative nature of the conclusions on cost-effectiveness should be highlighted.