A Skeptical Look at Under Armour Mouth Guards

Stephen Barrett, M.D.
November 30, 2014

Performance Mouthwear has been engineered to unlock your power and potential. It’s all in you, but blocked by one of the human body’s instinctive reflex systems – teeth-clenching. With safe, custom-built Performance Mouthwear, athletes in any sport – from football to golf to hockey – can capitalize on innovation that makes you stronger, faster and better [2].

The site further claims:

Clenching the jaw triggers the production and release of a cascade of hormones, including cortisol, the stress hormone. Performance Mouthwear prevents teeth clenching and relieves pressure on the temporomandibular joint (TMJ). By preventing the excessive production of hormones, the body is able to unlock its full potential [3].

These products are obtained through dentists who send molds of the patient’s top and bottom teeth to the Bite Tech’s lab, which makes the device. There are three models. The UA Performance Mouthguard is for contact sports. The UA Performance Mouthpiece is for noncontact sports. Both cost the the dentist $160 and retail for $495 (plus the cost of the dentist’s services). The UA Performance Allow Mouthpiece, which has a metal crosspiece, costs the dentist $370 and retails for $950 [4]. In contrast, standard mouthguards worn to simply protect teeth during contact sports are available through retail outlets for less than $20. There is no logical reason to wear a mouthpiece for noncontact sports.

Dentists obtain the Performance Mouthwear products from Patterson Dental, a leading dental supplier. “Authorized providers” can also purchase a $995 “launch kit” that includes brochures, product samples, a coupon for one device, and a listing on underarmour.com [4]. At least two competitors are selling similar products with similar claims. Makkar Athletics Group offers its Pure Power Mouthguard (PPM) through dentists that practice “neuromuscular dentistry.” The cost ranges from $595 to $2,250 plus dental fees. Dental Lab Direct sells Neonbrite SportsEdge Sport Mouthpieces direct to consumers for $196.

The discussion below examines whether “performance” mouthwear products are likely to provide any benefit other than protecting the wearer’s mouth and jaw.

Background History

Beliefs that custom-made mouth splints can increase athletic performance have been around for more than 50 years. In the early 1980s, Sports Illustrated, Runner’s World, and other magazines reported how prominent athletes believed that wearing a mouth appliance had increased their strength and stamina. In 1982, a Journal of the American Dental Association (JADA) article said that in the 1950s and 1960s two dentists reported improved performance for athletes fitted with mouthguards. These dentists stressed that the primary value of the guards was protection from injury by acting as a “shock absorber.” [5] Later, however, other dentists claimed that the benefits could be explained by the theories of “applied kinesiology.”

Applied kinesiology (AK) is an elaborate pseudoscience initiated in 1964 by chiropractor George Goodheart. Its basic notion is that every organ dysfunction is accompanied by a specific muscle weakness, which enables diseases to be diagnosed through muscle-testing procedures. The most common test purports to measure muscle strength by pulling down the patient’s arm after placing substances in the patient’s mouth or by touching various parts of the patient’s body.

Mouth-splint advocates claimed that failure of the teeth to fit together properly can have far-reaching effects on the rest of the body and that temporomandibular joint (TMJ, jaw joint) problems can cause weakness and disease far from the joint itself. These notions were widely promoted to dentists by Harold Gelb, D.D.S., who directed the Temporomandibular Joint Clinic of the New York Eye and Ear Infirmary from 1958 to 1979 and subsequently served as a clinical professor at two dental schools. Gelb designed the Mandibular Orthopedic Repositioning Appliance (“MORA”) and used applied kinesiology muscle-testing to diagnose and treat TMJ problems [6].

The concepts of applied kinesiology clash with scientific knowledge of human anatomy, physiology, and the causes or treatment of disease. Differences from one muscle test to another may be due to suggestibility, distraction, variations in the amount of force or leverage involved, and/or muscle fatigue [7]. In the 1982 JADA report, Charles Greene, D.D.S., a noted TMJ researcher, commented:

As far as sports go, these appliances came out of nowhere. They were originally developed for TMJ disorders. Suddenly, they are part of the armamentarium of a small group of dentists who claim these appliances affect other parts of the body. . . . One day it’s a plastic appliance for the jaw and the next day, for the whole body [5].

The JADA report described three studies in which people were tested while wearing special mouth splints and placebo devices. There was no difference in strength from one device to another, which suggests to me that any reported benefits are due to the placebo effect, day-to-day variability, suggestibility, or wishful thinking. Another study, reported in 1984, found no difference in strength in 14 football players who wore no mouthpiece, a placebo mouthpiece, or a MORA device [8].

What Is the Evidence?

Bite Tech does not rely on AK theory but contends that its benefits have a hormonal basis. Its literature states that athletic competition triggers a ‘fight or flight” reaction that includes clenching of the jaw and that “the clenched jaw and teeth compress the TMJ, triggering the release of excess amounts of performance-sapping hormones (like cortisol) that produce stress, fatigue and distraction.” [8] The company further claims:

UA Performance Mouthwear helps the human body help itself by unlocking the power of the jaw. Patented ArmourBite™ Technology prevents your teeth from clenching and pivots your jaw forward to relieve pressure on the TMJ. Gone are the excess negative hormones and the energy-draining effects, so the body can now unleash its full potential. Independent studies conducted at some of the nation’s top universities and research centers have proven the undeniable advantages of UA Performance Mouthwear [9].

I do not believe this explanation is valid.

  • Stress causes the adrenal glands to release hormones that affect body function, but jaw-clenching is a result of hormone production, not the cause—and it does not cause stress throughout the body.
  • The temporary changes due to adrenal hormone release (such as increased blood flow to the muscles of the arms and legs) will increase performance of these muscles not “sap” it.
  • A few laboratory studies have found that mouthguard use was associated with various things the researchers measured, but I do not believe these can be directly translated into increased performance during athletic events. There is also reason to doubt the validity of their findings. Most studies studies lacked appropriate controls, the numbers of people studied were small, and/or the researchers regarded small changes as significant when they were not. For example, one study Bite Tech cited found that participants reacted more quickly to sounds or a computer screen cue when they wore a mouthpiece than when they did not. But the average difference in reaction times between groups was only 18.5 thousandths of a second for the sound signal and 2 thousandths of a second for the visual cue [10]. These differences have no practical significance.
  • Self-confidence can increase athletic performance, and belief in a product may increase self-confidence. But in the long run, success is far more likely to be based on natural ability and optimal training.

A “literature review” [11] written in 2009 by Mark Roettger, D.D.S., executive director of the Bite Tech Research Institute and a consultant for the company, cites 22 references, but I don’t believe any of them are significant. A few that measured athletic performance were reported at least 25 years ago by Gelb and/or his associates. The rest, it appears to me, mainly evaluated laboratory findings (in rats and people) rather than performance in athletic events. Searching MEDLINE, I found a few studies which demonstrated that using a mouthguard did not interfere with athletic performance, but I found none that demonstrated improvement.

In 2014, the British Advertising Standards Authority reviewed the evidence and ordered Mouthwear Technology Ltd (dba Performance Mouthwear UK) to stop claiming that wearing an ArmourBite device increases strength, increases endurance, speeds up reaction time, reduces athletic stress, and reduces impact [12]. During the review process, the company said that over 5,000 dentists globally were licensed providers of the products.

The Bottom Line

Bite Tech, Inc. is promoting high-priced mouth appliances that it claims will enhance athletic performance by reducing stress on the jaw joints. The claim perpetuates the notion that repositioning the jaw can provide benefits in other parts of the body. Although mouthguards can protect against certain types of injury, there is no logical reason to believe they will lessen “stress” throughout the body or benefit athletic performance or general health. Although the company cites studies, I do not believe they are sufficient to back its claims.

  1. Bite Tech Helps Under Armour introduce jaw-dropping technology. Bite Tech Web site, accessed May 2, 2010.
  2. Your jaw is the key… unlock the power you never knew was there. Bite Tech Web site, accessed May 2, 2010.
  3. The technology is patented. The performance is proven. The advantages are undeniable. Bite Tech Web site, accessed May 2, 2010.
  4. Under Armour Performance Mouthwear: “The future is ours.” Patterson Dental launch presentation. Aug 9, 2009.
  5. Jakush J. Can dental therapy enhance athletic performance? Journal of the American Dental Association 104:292-296, 1982.
  6. Dodes J. The dentist and nutrition quackery. Nutrition Forum 2:77-80, 1985.
  7. Barrett S. Applied kinesiology: Phony muscle-testing for “allergies” and “nutrient deficiencies.” Quackwatch, March 10, 2009.
  8. Yates JW and others. Effect of a mandibular orthopedic repositioning appliance on muscular strength. Journal of the American Dental Association 108:331-333, 1984.
  9. UA Performance Mouthwear. Under Armour consumer brochure, 2009.
  10. Garner DP, Miskmin J. Effects of mouthpiece use on auditory and visual reaction time in college males and females. Compendium of Continuing Education in Dentistry, May 2010.
  11. Roettger M. Performance enhancement and oral appliances. Compendium of Continuing Education in Dentistry, July/Aug 2009.
  12. ASA adjudication on Mouthwear Technology Ltd, Nov 26, 2014.

This page was revised on November 30, 2014.