Rites of passage for American teenagers include obtaining a driver’s license, high school graduation, voting for the first time, and for many, prophylactic (preventive) extraction of their wisdom teeth. Many do not realize that there is a controversy in the dental community regarding the advisability of prophylactic wisdom tooth (third molar) extraction. Generally, dentists believe that the removal of third molars before the age of 22 prevents later disease and difficulty. Some dentists who specialize in public health opine that because only about one of eight third molars ever cause significant health problems, it does not make sense to remove them all. Information continues to evolve and will effect the future of dental treatment recommendations and patients’ comfort with their own decisions.
The web site of the American Association of Oral and Maxillofacial Surgeons, www.aaoms.org, carries a report titled “White Paper on Third Molar Data.” This thorough paper enumerates the reasons for prophylactic extraction of third molars. The authors refer to recent studies demonstrating that periodontal disease around third molars is a cause for more serious ailments including coronary artery disease, stroke, kidney disease, diabetes, and obstetric complications. Additionally, the AAOMS asserts that retained wisdom teeth of pregnant women are likely to cause low birth weight of their offspring.
The links between periodontal disease and systemic illness and low birth weight are driving dental insurance companies to cover more frequent dental care for some individuals. Medical associations and medical insurance companies advise physicians to refer their patients for dental treatment. Linking periodontal disease to third molars would have the effect of increasing demand for third molar extraction.
Of course, there is the more mundane issue of caring for the four most difficult to reach teeth. Third molars are more likely to require repeated restoration with fillings and crowns. They may develop root canal infections causing pain. The AAOMS paints a dim picture of teeth that are at once expensive to care for and a health hazard.
There is another side to the third molar story. Britain’s National Health Service publishes Effectiveness Matters, a newsletter dedicated to investigating and reporting the effectiveness of health care procedures. Their report, “Prophylactic Removal of Third Molars, Is It Justified?” is a 1998 article written before thorough understanding of the systemic effects of periodontal disease. The authors assert that only about a tenth of third molars ever cause oral disease. That is similar to the percentage of people who develop problems with their gall bladder or appendix. Therefore, just as general surgeons do not suggest removal of all asymptomatic gall bladders and appendixes, oral surgeons should not remove all third molars. They go on to describe the common side effects of third molar extraction: pain that lasts for an average of over two days, swelling, infection and damage to the nerve that gives sensation to the lip and tongue. Infrequently, there may be damage to the temporo-mandibular joint (jaw joint), creation of an opening between the sinus and the mouth (oro-antral fistula), damage to other teeth, and fracture of the lower jaw.
This article is a “meta-analysis”; that means that it is based on the results of a collection of studies of third molar disease and surgical treatment and outcomes. By a complicated formula and reasoning, the authors of “…Is It Justified?” determine that those who leave third molars alone until they become symptomatic (infected or otherwise pathologic) are much less likely to have a bad outcome than those who have their wisdom teeth removed preventively.
Another issue that drives dentists to recommend preventive removal of third molars is the sense that erupting third molars (third molars growing in) will cause crowding of the front teeth. In another meta analysis, “Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults” (Cochrane Database Syst Rev. 2005 Apr 18;(2):CD003879), authors did not find evidence supporting the removal of third molars to prevent the crowding of front teeth.
Complicating this controversy is the report “Pathology-free third molars: assessing the perceived risk of future pathology,” (Kostopoulou, et. al., British Dental Journal, 2000; 188: 28-31). The authors showed asked 10 oral surgeons and 18 general practitioners to evaluate x-ray films of the third molars of 36 patients. Interestingly, there is little agreement when the authors ask the participants to predict the risk of the third molars developing pathology (disease). The conclusion of this paper includes this admonition: “The results emphasise the value of the development of consistent criteria for intervention and of appropriate training before applying such criteria.”
This difference of opinion leaves the patient and perhaps their parents with a difficult decision. It is important to listen carefully to their dental advisors, their general dentist and their oral surgeon. Read the informed consent materials and ask questions. Patients must then decide if the recommendations of third molar extractions make sense to them. Then patients will have to live with the good and bad results of their choices.