If you have been following the subject of concussions in sports for any length of time, as I have for more than a decade, the question always seems to come up: do mouth guards prevent concussions?
The answer, at least to this point, seems to continue to be no, or, perhaps more precisely, we don't know.
Why am I revisiting the subject? Well, it seems I caught some flak when I recently suggested that a story in a new book about a college athlete who was allowed to continue playing contact sports - despite a history of multiple concussions - on the condition that she wear a certain kind of mouth guard, sent the wrong message by implying that mouth guards can prevent concussions.
One of the co-authors of the book claimed that I hadn't done my homework, suggested, erroneously, that I had not taken the time to check the literature carefully before completely trashing mouthguards (which I didn't do), and urged me to enlighten readers of MomsTeam about what the author claimed was the current mixed state of research on the subject, including a preliminary, pilot study of college football players reported in the journal Dental Traumatology1 in 2009 that claimed to find a protective effect.
Well, to begin with, the health and safety editors of MomsTeam and I were well aware of the journal article that the book author cited, and that one of the co-authors of that study was the manufacturer of a line of mouth guards. Indeed, the book review links to an article by Dr. William P. Meehan, director of the Sports Concussion Clinic at Children's Hospital Boston and MomsTeam's new concussion expert, which refers to the study, among others, but concludes that whether mouth guards prevent concussions, remains unclear. For the past decade, we have been following the mouth guard controversy and have been waiting for a well-designed peer-reviewed study to come out establishing, once and for all, that mouth guards prevent, or reduce the risk, of concussion.
In June 2011, Chicago Tribune Health Editor, Julie Deardorff, did her own research for an article she wrote for the newspaper, "Can mouth guards and football helmets really prevent concussion?" She called me asking whether I knew of any recent studies establishing that mouthguards prevented concussions.
I again reviewed the literature, including a January 2011 article in the journal Clinics in Sports Medicine by researchers at Boston University and the Sports Legacy Institute, including among the co-authors MomsTeam's first concussion expert, Dr. Bob Cantu),2 which confirmed her conclusion, based on a comprehensive review of the medical literature to date (109 footnotes!), that no such studies existed. Julie's advice to athletes: wear mouth guards to protect against facial and dental injuries.
Interestingly, as support for the view that mouth guards prevent concussions, the book author's e-mail to me also contained an excerpt from the Cantu, et. al. article, commenting on a 2005 study of National Hockey League players,3 which found that the concussion rate was 1.42 times greater in players who did not wear mouth guards compared with those who did, but that the difference was not statistically significant.
The same study, as later noted in a 2009 literature review in the British Journal of Sports Medicine, including two of the authors of the 2005 study,4 did note that symptom severity on a concussion evaluation post-concussion symptom scale was found to be significantly worse in athletes who were not wearing mouth guards than in those who were.
But a reduction in symptom severity, of course, is not the same as saying mouth guards prevent concussions; to suggest otherwise is to try to compare apples to oranges.
Indeed, not only does the 2011 literature review by Dr. Cantu and his Boston University colleagues state that "there is little evidence that mouth guards provide protection against concussion," and criticize the 2009 study of college athletes reported in Dental Traumotology1 as being marked by "several design flaws", but it concludes with the following statement:
Although mouth guards have been shown to be effective in preventing dental and orofacial injury, there is currently no evidence that standard or fitted mouth guards decrease the rate or severity of concussions in athletes. The bulk of the evidence indicating a potential protective effect of mouth guards on concussion incidence has been based on a limited case series studies and retrospective, non-randomized, cross-sectional surveys. There is also evidence that mouth guard use does not result in any difference in neurocognitive test performance after concussion.
The preponderance of evidence seems to indicate that helmets and mouth guards provide a significant benefit in protecting against many catastrophic head, neck and orofacial injuries. However, there is not yet significant evidence to advocate their effectiveness in preventing concussion. ... Although newer equipment remains a promising potential tool in minimizing concussion severity and incidence, other methods such as rule changes, improved concussion education, and proper coaching and training may prove more effective in the immediate future.
Waiting for Godot?
So where do we go from here?
I would love nothing more than be able to report to MomsTeam readers that mouth guards in general, or a particular mouth guard, protects against or reduces the severity of concussions.
But until such evidence is found, MomsTeam and I will continue to work - as we have for the past 14 years - towards a reduction in the severity and number of concussions in youth and high school sports by advocating, along with such groups as the American Academy of Pediatrics and the National Athletic Trainers' Association, for rule changes (such as the ban on body checking in youth hockey at the Pee Wee level and below, and new rules limiting contact practices in Pop Warner football) and stricter enforcement of existing rules, improved concussion education (which MomsTeam will continue to provide in its comprehensive concussion center), proper coaching (such as training youth hockey players how to anticipate body checks and teaching youth and high school football players how to tackle with their heads up, as my friend, Bobby Hosea, has been training coaches to do for more than a decade) and concussion training (now required of coaches by law in most states).
Update #1: On August 16, 2012, the Federal Trade Commission announced a settlement prohibiting mouth guard manufacturer Brain-Pad from making claims that its product reduced the risk of concussion. I am not in the least bit suprised!
Update #2: Three studies released within weeks of each other in March 2013 (5,6,7) all conclude the same thing: there is no valid evidence that mouth guards reduce the risk of concussion.
Update #3: A July 2014 study of high school football players by researchers at the University of Wisconsin published in the American Journal of Sports Medicine (8) found that the rate of sport-related concussion (SRC) for players who wore a specialized or custom-fitted mouth guard was significantly higher than for players who wore a generic mouth guard provided by their school (a finding McGuine and his co-authors admitted was "unexpected", and might have been due to a variety of factors, including chance, or to players with custom mouth guards feeling that they have greater protection against a sport-related concussion and play with less regard or fear for sustaining an injury). The study agrees with the opinion of previous researchers that "well controlled prospective studies in athlete populations have not shown that [the fact that mouth guards have been shown in laboratory settings to dissipate impact forces sustained to the jaw] translates into a decreased risk of SRC."
1. Singh GD, Maher GJ, Padilla RR. Customized mandibular orthotics in the prevention of concussion/mild traumatic brain injury in football players: a preliminary study. Dent. Traumatol 2009;25(5):515-21.
2. Daneshvar DH, Baugh CM, Nowinski CJ, McKee AC, Stern RA, Cantu RC. Helmets and Mouth Guards: The Role of Personal Equipment in Preventing Sport-Related Concussions. Clin Sports Med 2011; 30: 145-163.
3. Benson BW, Meeuwisse WH. Ice Hockey injuries. Med Sport Sci 2005;49:86-119.
4. Benson BW, Hamilton GM, Meeuwisse WH, et al. Is protective equipment useful in preventing concussion? A systematic review of the literature. Br. J. Sports Med 2009;43(suppl 1):i56-67.
5. Giza C, Kutcher J, Ashwal S, et al. Summary of evidence-based guideline update: Evaluation and management of concussion in sports: Report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology 2013;DOI:10.1212/WNL.0b013e31828d57dd (published online before print March 18, 2013)("There is no compelling evidence that mouth guards protect athletes from concussion.")
6. McCrory P, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. Br J Sports Med 2013;47:250-258 (There is no "good clinical evidence mouth guards will prevent concussions, although they have a "definite role in preventing dental and orofacial injury,")
7. Benson B, McIntosh A, Maddocks D, Herring S, Raftery M, Dvorak J. What are the most effective risk-reduction strategies in sport concussion. Br J Sports Med 2013;47:321-326 (characterizing studies that appeared to show mouth guards reduced concussion risk, including the Sing study (n. 1) as having "several limitations which threaten the validity of their results.")
8. McGuine TA, Hetzel S, McCrea M, Brooks AM. Protective Equipment and Player Characteristics Associated With the Incidence of Sport-Related Concussion in High School Football Players. Am J Sports Med. 2014;20(10)(published online ahead of print, July 24, 2014 as doi:10.1177/036354651541926.