Opposition to Prophylactic Removal of Third Molars (Wisdom Teeth)

Excessive health care in the United States has been documented by numerous studies. It results in waste of limited funds and harm to millions of people, not excluding death, because even the safest treatment is not without risk.¹ The obvious solution, when effectively applied, is “evidence-based practice,” which minimizes unnecessary procedures and reduces costs. The public is already aware that some surgical procedures, such as tonsillectomy, are no longer routinely performed in the absence of infection to prevent future infection. Yet, there are procedures such as the prophylactic removal of third molars that result in injury to tens of thousands of people at a cost of billions of dollars, about which the public is ill informed and thus subject to the risks of unnecessary surgery.²

Accordingly, the American Public Health Association (APHA) calls for dental care, like all aspects of health care, to be evidence based. APHA encourages the collection, review, dissemination and policy applications of knowledge supporting or negating the efficiency and cost-effectiveness of specific forms of dental care. .. Encourages dental professionals, consumers, private and public health care financing agencies, and state licensing authorities to adopt an evidence-based approach to dental services, in order to rationally control costs, help assure quality and favorable outcomes and extend more affordable dental care to a wider public . . ..³

All health-related organizations should promote evidence-based practice and discourage treatment that is of questionable value and that has the potential to cause significant injury to the public.

No one questions the removal of third molars, or any other tooth, where there is evidence of pathological changes such as infections, nonrestorable carious lesions, cysts, tumors, and damage to adjacent teeth. But the contention by many dentists, including oral surgeons, that retaining third molars, whether or not impacted, will likely lead to sufficient harm does not justify removing all third molars.

The main arguments for prophylactic removal of third molars are as follows: eruption is unpredictable; adjacent teeth could be damaged; the teeth may harbor pathogenic bacteria that may cause periodontal disease and may contribute to low infant birthweight and other diseases such as diabetes, cardiovascular disease, and stroke; eruption may cause crowded or crooked teeth; and they are easier to extract and cause less morbidity when extracted in adolescence.^4–6

None of these contentions is sufficient to support prophylactic extraction of third molars. Unpredictability of eruption is not valid because most wisdom teeth erupt, and only a small percentage of those that remain unerupted or partially erupted cause problems that warrant extraction. All periodontically diseased teeth harbor pathogenic bacteria and require treatment by general dentists, dental hygienists, and periodontists, whose goal is to retain, not extract, them. Presence of third molars in conjunction with systemic diseases represents association, not causation.

Because the rationale to remove all third molars to reduce morbidity or prevent cysts and crowding of anterior teeth does not meet the evidence-based test, the current emphasis on third molars as a potential cause of periodontal disease and other debilitating or life-threatening conditions warrants more detailed analysis. Since the 1990s, the American Association of Oral and Maxillofacial Surgeons has been a major sponsor of research exploring periodontal disease in third molars.⁷

The few studies of long-term retention of impacted teeth have shown little risk of harm. In one large study, in which 3702 “neglected” impactions (96% third molars) were retained for an average of 27 years, only 0.81% showed dentigerous cystic changes. Further, any type of pathological change can be expected eventually in approximately 12% of an impacted third-molar population and 1.8% of the general population, including those with impacted teeth. Accordingly, the authors questioned routine removal of impacted third molars.⁸

A similar panoramic radiograph study of 1418 women found 16% had “moderate” pathological conditions, consisting “in most cases of a slightly widened follicle or resorption of the crown. A new examination 12 years later revealed unchanged conditions in 85% of the cases.”⁹

The 12% incidence of pathology referred to previously does not include pericoronitis or inflammation and infection of the gum tissue around a tooth as it erupts, which is distinguishable from normal “teething.” Estimates range from 6% to 10%. Adding an average of 8% raises the potential for third-molar pathology to 20%. Also, it has been reported that as many as one third of the population may experience some discomfort at one time or another associated with wisdom teeth; thus, there is likely need for, at most, one third of the extractions currently being done.¹⁰

Third-molar surgery is not without risk of injury. The most common injury is temporary and permanent paresthesia, which has been documented by numerous studies. Incidence of permanent paresthesia of the mandibular nerve varies from a low of 0.33% to a high of 1%.^11,12 There is also injury to the temporomandibular joints (TMD/TMJ), which has been reported at 1.2% for patients aged 15 to 20 years.13 The nearly 6000 oral and maxillofacial surgeons account for 94% of the 10 million third-molar extractions in the United States annually, averaging 52.7 cases a month.^14,15 Thus, an estimated 3.8 million people experience 5 million mandibular third-molar extractions each year. As a consequence, as many as 17,000 to 50,000 people have some degree of permanent mandibular nerve paresthesia and tens of thousands experience TMD/TMJ injuries, an unknown number of which also become permanent. Furthermore, patients experience an average of 2.7 days, more than 10 million days in aggregate, of discomfort and disability―pain, swelling, bruising, and malaise―and absence from school and loss of work and income after uncomplicated third-molar extractions. Other risks include inadvertent fractures of the jaws, damage to the maxillary sinus, damage to adjacent teeth, and occasional deaths attributed to general anesthesia.^16,17

In a literature review of 40 studies involving third-molar extractions, the authors concluded that, “In the absence of good evidence to support prophylactic removal, there appears to be little justification for the removal of pathology-free impacted third-molars.”18 A similar Cochrane Review on interventions for treating asymptomatic impacted wisdom teeth advised that watchful monitoring may be a more appropriate strategy. “Prudent decision-making, with adherence to specified indicators for removal, may reduce the number of surgical procedures by 60 percent or more.”19

A further review of the literature on third-molar extraction by an oral pathologist concluded, third molars without associated pathology or developmental conditions are sacrificed, usually in adolescents and young adults, like no other human tissue, in the name of preventive dental care . . . in more than 98 percent of cases, there is no apparent benefit to prophylactic third-molar extraction in adolescents. The concept that all third molars (functional or nonfunctional) should be extracted prophylactically should be abandoned.”²⁰

Consequently, the National Health Service in Great Britain adopted the policy that, “The practice of prophylactic removal of pathology-free impacted third molars should be discontinued . . .. There is no reliable evidence to support a health benefit to patients from the prophylactic removal of pathology-free teeth.”²¹ In the United States, millions of mostly young people continue to have prophylactic extraction of their wisdom teeth in the belief that it is necessary. This practice is not evidence based and needs to be discouraged by providing the public with information essential to making an informed decision.

The 2000 US Surgeon General’s report, Oral Health in America, and Healthy People 2010 emphasize the role of public health and health care providers, educators, and researchers in improving the public’s health literacy.^{22, 23} The American Dental Association defines oral health literacy as “the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate oral health decisions.”²⁴

Improvement in health literacy requires more than exposure to information, much of which can appear to the public as confusing if not contradictory; it also requires provision of “clear, understandable science-based health information to the American people,” including health care providers.²⁵ It requires assistance in interpretation by public health organizations, educational institutions, and agencies with no financial or personal interests one way or the other.

Accordingly, the American Public Health Association:

1. Recommends that public education about the removal of third molars (wisdom teeth), like the removal of any teeth, should be based on evidence of diagnosed pathology or demonstrable need; 
2. Opposes prophylactic removal of third molars, which subjects individuals and society to unnecessary costs, avoidable morbidity, and the risks of permanent injury; 
3. Recommends that the Agency for Healthcare Research Quality and the National Institutes of Health, agencies of the US Department of Health and Human Services, and other independent researchers call for convening an expert panel that considers evidence-based research on the effectiveness and appropriateness of prophylactic removal of third molars and generates a consensus statement; 
4. Recommends that oral health researchers and funding agencies include in their research agendas support for the application of evidence-based dental practice, to include issues such as the prophylactic extraction of third molars and how to most effectively translate evidence-based science into the practice of dentistry;
5. Urges all public health agencies and dental professional organizations to disseminate information explaining why prophylactic removal of third molars is not recommended, in keeping with their dedication to improving the health literacy of the public and its consequent ability to make informed health care decisions. 

References

1. Brownlee S. Overtreated: Why Too Much Medicine Is Making Us Sicker and Poorer. New York, NY: Bloomsbury; 2007. 
2. Friedman JW. The prophylactic extraction of third molars: a public health hazard. Am J Public Health. 2007; 97:1554–1559. 
3. American Public Health Association. APHA policy statement 97-06. Evidence-based dental care. Washington, DC: American Public Health Association; 1997. Available at: http://www.apha.org/advocacy/policy/policysearch/default.htm?id=140. Accessed November 187, 2008.
4. White paper on third molar data. Rosemont, Ill: American Association of Oral and Maxillofacial Surgeons; 2007. Available at: www.aaoms.org/docs/third_molar_white_paper.pdf. Accessed January 25, 2008.
5. Wisdom teeth [pamphlet]. Rosemont, Ill: American Association of Oral and Maxillofacial Surgeons; 2005.
6. Third molars: diffusing an oral time bomb―AAOMS 3rd Molar Clinical Trials. Press conference. Rosemont, Ill: American Association of Oral and Maxillofacial Surgeons; 2005.
7. Wisdom teeth [pamphlet]. Rosemont, Ill: American Association of Oral and Maxillofacial Surgeons; 2005.
8. Stanley HR, Alattar M, Colett WK, Stringfellow HR Jr, Spiegel EH. Pathological sequelae of “neglected” impacted third molars. J Oral Pathol. 1988;17:113–117. 
9. Ahlqwist M, Gröndahl HG. Prevalence of impacted teeth and associated pathology in middle-aged and older Swedish women. Community Dent Oral Epidemiol. 1991;19(2):116–119.
10. Friedman JW. The prophylactic extraction of third molars: a public health hazard. Am J Public Health. 2007; 97:1554–1559. 
11. Valmaseda-Castellon E, Berini-Aytes L, Gay-Escoda C. Inferior alveolar nerve damage after lower third molar surgical extraction: a prospective study of 1117 surgical extractions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001;92:377–383. 
12. Wisdom teeth [pamphlet]. Rosemont, Ill: American Association of Oral and Maxillofacial Surgeons; 2005.
13. Huang GJ, Rue TC. Third-molar extraction as a risk factor for temporomandibular disorder. J Am Dent Assoc. 2006;137:1547–1554.
14. Moore PA, Nahouraii HS, Zovko JG, Wisniewski SR. Dental therapeutic practice patterns in the US. I. Anesthesia and sedation. Gen Dent. 2006;54:92–98. 
15. 2005–06 Survey of Dental Services Rendered. Chicago, Ill: American Dental Association Survey Center; 2007.
16. Tulloch JFC, Antczak-Bouckoms AA, Ung N. Evaluation of the costs and relative effectiveness of alternative strategies for the removal of mandibular third molars. Int J Technol Assess Health Care. 1990;6:505–515.
17. D’eramo EM, Bookless SJ, Howard JB. Adverse events with outpatient anesthesia in Massachusetts. J Oral Maxillofac Surg. 2003;61:793–800.
18. Song F, Landes DP, Glenny AM, Sheldon TA. Prophylactic removal of impacted third molars: an assessment of published reviews. Br Dent J. 1997; 182:339–346. 
19. Mettes TG, Nienhuijs ME, van der Sanden WJ, Verdonschot EH, Plasschaert AJ. Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults (Review). Cochrane Database Syst Rev. 2005 Apr 18(2):CD003879. 
20. Daley TD. Third molar prophylactic extraction: a review and analysis of the literature. Gen Dent. 1996;44:310–320. 
21. National Institute for Clinical Excellence. Guidance on the extraction of wisdom teeth. London, UK: National Institute for Clinical Excellence; 2000. Available at: www/nice.org.uk/nicemedia/pdf/wisdomteethguidance.pdf. Accessed November 18, 2008.
22. US Department of Health and Human Services. Oral health in America: a report of the Surgeon General. Rockville, Md: US Department of Health and Human Services, National Institute of Dental and Craniofacial Research, National Institutes of Health, 2000.
23. Healthy People 2010: Understanding and Improving Health. Washington, DC: US Department of Health and Human Services; 2000. Also available at: http://web.health.gov/healthypeople/document/. Accessed January 25, 2008. 
24. Crozier S. Surveys, symposium target oral health literacy. ADA News. Nov 8, 2007. Available at: www.ada.org/prof/resources/pubs/adanews/adanewsarticle.asp?articleid=2767. Accessed December 5, 2007 
25. Proceedings of the Surgeon General’s Workshop on Improving Health Literacy. September 7, 2006. National Institutes of Health, Bethesda, Md. Available at: www.surgeongeneral.gov/topics/healthliteracy/toc.htm. 

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