#tbt Mouth Guard BS Research!

This was originally posted in May, not a long throwback, but since football started I have been hit up with this question a lot.  So here is the “truth” about this research.  I love the effort and attempt to find a reason; however when you have a critical and FUNDAMENTAL flaws then present it in a way that could be considered fraudulent I have a major problem.  I would also like to add that this research has not been pulled by the publisher.  This is exactly how we get in trouble, the Academy of General Dentistry needs to address this, now, as this peer-reviewed “science” is getting run in media…


The basic fundamentals we should be cognizant of here are: concussion is a BRAIN injury, the BRAIN floats inside skull, Physics dictates that the BRAIN will move depending on the forces applied to the skull/head (not always from a blow to that area), mouth gear cannot stop the BRAIN from moving, mouth gear cannot attenuate any forces to the skull/head that are not in the oral region, mouth gear does nothing for the skull/head when forces are placed on it in rotational, angular, acceleration or deceleration fashion.

Now that we have that all out-of-the-way this is the General Dentistry article I was asked to comment on.  On face value and from a “peer-reviewed” angle it seems all good.  A significant finding between custom mouth gear (noted as LM MG in article) and over the counter “boil and bite” mouth gear (noted as OTC MG).  However once you take a deeper look there are some peculiar problems, in my humble opinion – that comes later.

First, we should look at the possible limitations of this study that seems well populated and well thought out (honestly these were my first concerns before finding the real issue):

  • Were the injuries controlled for by football position? (we have documented this issue here)
  • Were the injuries controlled for by size of players/school they were playing?
  • Were the injuries controlled for by playing time? (more exposure more risk)
  • Were the injuries controlled for by game vs. practice?
  • Were all the injuries seen and recorded by a single MD or was it the ATC at each school?
  • Did any of the players have a previous history of concussion?
  • Was the study controlled based on practice habits of the teams? (do some hit more than others)
  • How do we know that every player complied with the “no wedging or chewing” rule? (this plays a massive role later)
  • The study says that all 412 subjects wore the same exact helmet, I find that: A) hard to believe and B) was the fit on every player the relatively the same?
  • Who funded this research? (no disclosure)

As you can see there is a litany of reasons I would have dismissed this research, if I were peer reviewing because those limitations are extremely real and realistic to control for in this type of study.  I wrote to the public relations group handling this research and was unable to get a straight answer on those questions I raised.  In the meantime I sent out the article to some better than average “stat nerds” and awaited a response.

While waiting I noticed something really troubling, as in a fatal flaw with the research.  In some places an oversight like this is intolerable, because letting this happen could set one up for producing “cooked” research.  I re-read the results section and saw this (emphasis mine):

One player was wearing a cut-off OTC MG with no support in the posterior occlusal area, and 2 players were not wearing an MG at the time of their injury; these 3 players were all in the OTC MG group.

The one player with the cut-off OTC MG disobeyed the instructions given by the lead author of this study, he modified the mouth guard.  This should have nullified the reporting of said injury.  The other two WERE NOT EVEN WEARING A MOUTH GUARD AT THE TIME OF INJURY!  Yet, they all were included in the results as an injury for the OTC MG group.

I may be some athletic trainer in the sticks of Illinois, but I do know a problem when I see one.  I feel that including all three of those injuries in the OTC MG concussion pool seems a bit off.  None of them complied with the study’s instructions, even though they were in a OTC MG “school”.  This study counts 16 concussions in that group, when in reality it was 13.  The “doubling” of concussions as touted by the research and the PR is both wrong and knowingly inaccurate.  If, and I mean IF, every other participant was following the protocol then the ratio was 13:8 not 2:1.

About that time I received the email from my “stat nerd” and he saw the same thing and gave me the following comments;

Only counting 14 concussions in the OTC MG group does one get a statistically significant result with chi-square adjusted single tail.  A very weak result.  All other measures the results are not significant.  With 13 concussions in the OTC MG group nothing is statistically significant.

Even if we were to include the cut-off mouth guard in the group only one stat run shows significance and it is not very strong to boot.  A more rigorous test like Fisher’s Exact Test two-tailed also shows no significance.  Below is a screen shot of the word document.

stat screen shot

This is quite the information.  How do data get included in a supposed peer-reviewed article that is obviously not part of the group?  How do people who have many more degrees and letters behind their name let this type of information slip through?  But wait there is more…

When I first read the results I passed over, without thought, a note identifying that there were 23 concussions and a player received a second concussion but that was also included in the stats (bringing total to 24).  The article never identified which group, LM MG or OTC MG, was unlucky enough to have two concussions from one subject.  However, with what we know about concussions it should have been easily understood to probably not count that second one due to predisposing history.  If the second concussion was also in the OTC MG group that again raises some serious concerns and changes the statistics.

After all my questions the numbers just don’t add up; we could very well be looking at 12:8 (OTC:LM) rather than a 16:8 ratio.

(Quick aside here 24 concussions out of 412 participants (5.8%) is a very low number for high school football, perhaps someone should look into what they are doing in those schools to keep the numbers down!)

So for those of you wanting and waiting for comment on this article; well when you look at the real numbers it comments for itself.  The real “commenting” on this has to do with the “snake oil” type approach of cooked research.  It is hard to find out who would gain the most from this, as no funding disclosure was made available but bad science is bad science.

Remember mouth gear is great for protecting against oral and dental injuries and every participant in a collision sport should be wearing one – you should also be wearing one if you or your family has spent some good money on your teeth.

When it comes to concussions, mouth gear will not attenuate or prevent or make you less likely to get one, period.


12:26pm CST: Here’s a statement from Robert Cook, Executive Editor, General Dentistry:

General Dentistry is reviewing the study, “Role of mouthguards in reducing mild traumatic brain injury/concussion incidence in high school football athletes,” to evaluate the data presented. This study was not funded by industry and Dr. Winters has no disclosures.

4 thoughts on “#tbt Mouth Guard BS Research!

  1. Mark Picot August 21, 2014 / 10:06

    Dustin, I agree 100%, Coup contra Coup concussion is in its own realm as a separate injury from anything a mouth guard can prevent and much of the research designs on mouth guards to date are flawed because they ignore occlusion or are just plain designed poorly. Just because the research designs are flawed, does not mean orthodontic appliances are not beneficial and are not better than to and bite. In fact the latest EEG data shows a consistent benefit to neck strength in their use, particularly in those with Tmd. The link above sheds new light on other vestibular issues, related to orthopedics, inner ear, facial nerves, the Tmj, ect. that confirms what many believe are the benefits of a form fitted mouth guard. When Temporal mandibular joint dysfunction symptoms exists, a Tmd appliance for sport is the best option. Those who display these vestibular symptoms during play, dizziness, nausea, headache, ear ringing, but don’t evaluate as having Coup contra Coup concussion in Impact testing, should consider a Tmd evaluation. Although they have similar/overlapping symptoms Coup contra Coup should not be categorized as the same injury as vestibular injury. Can you agree.

  2. jbloggs August 23, 2014 / 12:20

    Allison Brooks, MD, PhD recently published a study that found:

    “While helmet brand or age did not significantly affect the incidence or severity of sport-related concussion, prior concussion and the use of specialized or custom mouthguards were associated with an increased incidence of the injury. This is in contrast to manufacturers’ claims that a specific brand of helmet or type of mouthguard can significantly reduce the risk of concussion.”

    makes you go hmmm….

    The helmet result was expected but the finding that custom mouthguards is associated with increase in the rate of concussion is outstanding.

    Sports medicine research is population by quacks and charlatans.

    Question every published study. Bad study design, flawed methodology and rampant conflicts of interest are endemic.

  3. Mark August 28, 2014 / 21:35

    There is a scientific approach to neuromuscular dentistry, supported by independent research, it uses EEG review to show the benefits of an optimum bite. The study mentioned above where custom guards caused more concussions, completely ignored “occlusion”. What is meant by this is where the jaw bones rest, when the teeth are clenched. If they are in a negative position because of a poorly fitted mouth guard, it more than often will have a negative effect on neck strength symmetry or other related vestibular issues. Also, how do we know if these “concussions” were not vestibular trauma symptoms. If a mouth guard cannot prevent a coup contra coup concussion, then how does it contribute to a raised number of events, its flawed reasoning. Adolescents who are post orthodontic are the most likely candidates for these vestibular issues due to occlusal imbalances. Yet these factors are not even part of any discussion related to neck strength or more importantly the vestibular system. Because concussion research is just in its infancy, this subject remains an enigma, even when the latest research suggests vestibular trauma may account for a significant percentage of reported injury. It cannot and should not be ignored.

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