Mouthguards significantly reduce orofacial and brain injuries
Executive summary
Clinical evidence across multiple systematic reviews and trials shows mouthguards clearly reduce orofacial and dental injuries—meta-analyses report that the risk of orofacial trauma is roughly 1.6–1.9 times higher when a mouthguard is not worn [1] [2]. The evidence that mouthguards prevent concussions or meaningful brain injury is mixed: some biomechanical and narrative reviews suggest mouthguards can reduce transmitted impact energy to the head [1] [3], while randomized and prospective studies have not consistently shown reduced concussion incidence or improved neurocognitive outcomes [4] [5].
1. Orofacial protection: a strong, consistent finding
Multiple high-quality syntheses conclude mouthguards substantially lower the incidence and severity of dental and intra-oral injuries. Systematic reviews and meta-analyses summarized in Sports Medicine and later reviews conclude mouthguards should be used in sports with significant orofacial injury risk because users have lower rates of dental trauma [6] [7] [2]. An umbrella review and recent overviews confirm that custom-made mouthguards are especially effective and that policy and education to increase use are commonly recommended [8] [9].
2. The concussion question: conflicting evidence, limited trials
The literature does not deliver a clear yes-or-no on concussions. Older and some contemporary trials find no significant difference in concussion rates or post-injury neurocognitive deficits between mouthguard users and non-users (for example, Mihalik et al. and a college basketball study) [4] [5]. Systematic reviews note inconsistent findings and say no definitive conclusion can be drawn about concussion prevention at present [2]. This is a genuine disagreement in the evidence base, not mere rhetoric.
3. Biomechanics and plausible mechanisms that argue “maybe”
Laboratory and narrative reviews point to plausible protective mechanisms: by separating dental arches and absorbing or redistributing impact forces, mouthguards can reduce force transmission to cranial structures, and some finite-element and impact studies show reduced energy reaching targeted head regions [10] [3] [1]. These mechanistic data support the hypothesis that mouthguards could lessen severity of some head acceleration events, but they are not the same as clinical proof of fewer concussions [3] [1].
4. Quality, scale, and design problems limit answers on brain injury
Authors repeatedly flag methodological limitations: heterogeneous study designs, small sample sizes, varying mouthguard types, inconsistent injury definitions, and sparse large-scale, prospective trials [2] [1]. Because many studies mix sports, age groups, and mouthguard designs, pooled estimates for concussion prevention carry wide uncertainty; available sources explicitly note the need for higher-quality research [2] [8].
5. What type of mouthguard matters—custom designs lead the field
Recent reviews and an umbrella analysis highlight that custom-made mouthguards (professionally fitted) perform best for preventing dental injury and may offer superior fit and shock-absorbing characteristics [8] [3]. Many policy statements and professional endorsements (e.g., World Dental Federation referenced in reviews) favor custom devices where feasible [3] [1].
6. Policy implications: low-regret measure for orofacial safety, cautious on concussion claims
The consensus across reviews is straightforward for orofacial protection: mandate or strongly promote mouthguard use in high-risk sports because benefits for teeth and soft tissues are clear [2] [8]. For concussion prevention, the prudent policy stance is cautious: promote mouthguards as part of a broader head-injury strategy (helmets, rule changes, education, impact monitoring) while acknowledging the clinical evidence for concussion reduction is inconsistent [2] [4].
7. Where the research should go next
Sources call for large, sport-specific, prospective trials that standardize mouthguard type, exposure measurement, and concussion definitions, and for instrumented mouthguards to deliver objective head-acceleration data in real time [11] [8] [1]. Those studies would directly test whether the biomechanical reductions in transmitted energy translate to fewer or less severe concussions [11] [1].
Limitations and final note: available sources do not mention definitive, large-scale randomized trials proving mouthguards prevent concussions in all contact sports; they do support strong, repeated evidence that mouthguards reduce orofacial injuries and that mechanistic data make the brain-protection hypothesis plausible but unproven [2] [6] [3].