Injury prevention vs Performance – Do mouthguards prevent injury or are they just an unnecessary burden to aerobic performance?

Since the design of the first mouthguards in the late 1890’s, they have been commonly used as a way to prevent oro-facial injuries and protect athletes during contact sports. Although widely available, there are large variations in how commonly they are worn across different sports and this is dependent on athletes’ preferences, such as how well they fit and if they restrict performance. We explore current attitudes towards athletes wearing mouthguards and explore whether now is the time to consider mandating their use in at risk sports to promote athlete health.

Mouthguards and orofacial injury

“Non-mouthguard use is associated with a 1.6-1.9 times increased risk of orofacial injury in at risk sports”¹

What are the main barriers to mouthguard use amongst elite and amateur athletes?

Mouthguards are available over the counter or via a dentist, to athletes from amateur and elite levels of competitions, but rates of use vary significantly. Athletes commonly cite not being required to wear them as the number one reason for non-use.² Individual sports adopt different approaches with some mandating their use at an international level, others at national level and some based on local guidance from coaches and parents.^3,4

Athletes reported a lack of encouragement by coaches and teammates as well as concerns that mouthguards could cause discomfort and hinder communication as additional reasons as to why they are not worn. Some athletes also worry that they may restrict ventilation and aerobic performance at higher intensities of exercise.

It has been suggested that clear messaging from coaches, fellow athletes and sports bodies could help to encourage :

• A culture of wearing mouthguards as ‘normal’ in at risk sports.
• Greater awareness amongst peers about the importance of mouthguard use.
• A culture of safe participation in sports by wearing a mouthguard.
• Greater awareness on using an appropriately fitted and comfortable mouthguard for the athlete.

Understanding and addressing the reasons why some athletes prefer not to use mouthguards could help to design policies that promote their safe use. This will require the involvement and input of coaches, fellow athletes and policies that help educate athletes on how to size and fit an appropriate mouthguard for injury prevention without restricting performance.

What do we know about the different types of mouthguards?

There are three main types of mouthguards available to athletes currently (as seen in the figure below):

1. Stock Mouthguards.
2. Boil and bite.
3. Custom made mouthguards.

The quality and protective ability of a mouthguard can be assessed using a combination of the types of materials used as well as the features of the mouthguard.⁵ They are ranked on a grade of 0-10, with grade 10 being the highest describing a custom-made mouthguard produced using improved materials, design as well as having passed an effective instrument test.^{1, 6} Materials that are better at absorbing impact and designs which protect the most at-risk teeth can improve the quality of a mouthguard.^{1, 4, 5}

Does the use of a mouthguard affect an athlete’s performance?

Many studies use VO₂ max (the maximum volume of oxygen in litres consumed per minute and adjusted for body weight) to assess performance during sports and exercise, citing it as the most reliable, reproducible and accurate measure of performance.⁷

A review paper looking at 14 studies (meta-analysis of all mouthguard types), showed that mouthguard use was associated with a reduction in VO₂ max and VE max (at maximal exercise) suggesting that mouthguards may be associated with a small reduction in maximal aerobic performance. Interestingly, a sub-group analysis in the same papers showed that when studies of custom-made mouthguards alone were analysed, these mouthguards were shown not to reduce performance, suggesting that there may be differences between mouthguard types.⁸ A recent systematic review of 312 studies across multiple sports, reported that custom made mouthguards, were superior to stock and poorly fitted mouthguards  in terms of maximal aerobic performance, ratings of comfort, stability, retention and ease of speech.⁹

Current evidence supports the use of well fitted mouthguards during at risk sports and suggests that any impact on aerobic performance is likely to be small and may be negated by using custom made mouthguards. This needs to be balanced against the cost which can be significantly higher for custom-made mouthguards.

Further research using “sports specific” performance measures such as (lactate thresholds, anaerobic capacity and grip strength) may also help us to better understand if mouthguards have any impact on athlete’s performance, during competition settings.

The holy grail; designing the performance enhancing mouthguard

Until recently, mouthguards have been used for the primary purpose of injury prevention. Newer technologies, and innovations however have allowed for new mouthguards to be made with the promise of being able to enhance performance or improve breathing efficiency during exercise. Although the mechanism of such claims remains unclear, it has been suggested that some mouthguards may encourage pursed lip breathing (PLB) patterns or improve the jaw position of athletes during exercise.

At present, these claims of performance enhancement remain theoretical, as there has been limited research to assess the impact of mouthguards in healthy individuals or at true maximal aerobic competition conditions with control comparisons.^{10, 11}

Conclusion – Key points

• Use of a well fitted mouthguard made from modern materials such as EVA is proven to help reduce the risk of oro-facial trauma in at risk sports.
• The most common reasons for not using mouthguards are, not being required to do so, cost, comfort and perceived adverse effect on performance.
• There are three main types of mouthguard (stock, boil and bite and custom-made) and there may be differences in how each type effects athletic performance. Custom-made mouthguards are reported to be more comfortable and less likely to adversely impact performance.
• Custom-made mouthguards are better tolerated than other types of mouthguards and may improve performance by altering breathing patterns. However, more research is needed to investigate this claim and more studies assessing a range of performance measures could be help build a better understanding of the role of mouthguards in sports.

Authors and Affiliations:

Payam Ghoddousi, Lynsey Abbey Joslin, Shahyr Shezad, Irfan Ahmed.

1. Dr Payam Ghoddousi is a GP Trainee based in London (UK) with an interest in Sports and Exercise Medicine as well as chronic disease prevention and management with lifestyle changes. Email: payam.ghoddousi@nhs.net
2. Lynsey Abbey Joslin is a medical student in London (UK) with an interest in sports and exercise medicine. Twitter: @AbbeyJoslin. Email: abbey.joslin.20@ucl.ac.uk
3. Shahyr Shezad is a medical student based in London (UK) with an interest in sports and exercise medicine as well as cardiovascular science. Email: shahyr.shezad.20@ucl.ac.uk
4. Dr Irfan Ahmed is a Sport & Exercise Medicine Registrar and General Practitioner based in London (UK). He has an interest in VO2 max, injury prevention and also using exercise to help prevent chronic disease and rehabilitate patients. Twitter: @Exerciseirfan

References

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2. Collins, C., McKenzie, L., Roberts, K., Fields, S. and Comstock, R., 2015. Mouthguard BITES (Behavior, Impulsivity, Theory Evaluation Study): What Drives Mouthguard Use Among High School Basketball and Baseball/Softball Athletes. The Journal of Primary Prevention, 36(5), pp.323-334.
3. Galic, T., Kuncic, D., Poklepovic Pericic, T., Galic, I., Mihanovic, F., Bozic, J. and Herceg, M., 2018. Knowledge and attitudes about sports-related dental injuries and mouthguard use in young athletes in four different contact sports-water polo, karate, taekwondo and handball. Dental Traumatology, 34(3), pp.175-181.
4. Tinoco, J., Sassone, L., Stevens, R., Martins, D., Grangeiro Neto, J. and Tinoco, E., 2020. Mouthguard use and attitudes regarding dental trauma among elite cross‐country mountain biking and field hockey athletes. Dental Traumatology, 37(2), pp.307-313.
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8. Caneppele TMF, Borges AB, Pereira DM, et al. Mouthguard use and cardiopulmonary capacity – a systematic review and meta-analysis. Sports Med Int Open 2017;1:E172–82.doi:10.1055/s-0043-117599pmid:http://www.ncbi.nlm.nih.gov/pubmed/30539104
9. Ferreira GB, Guimaraes LS et al. Is there enough evidence that mouthguards do not affect athletic performance? A systematic literature review. International Dental Journal. 2019;69(1):25-34. Published 2019 Feb. https://doi.org/10.1111/idj.12406
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11. Ahmed I, Fine P. ‘Injury prevention versus performance’: has the time come to mandate the use of mouthguards in all contact sports?. BMJ Open Sport Exerc Med. 2021;7(1):e000828. Published 2021 Jan 13. doi:10.1136/bmjsem-2020-000828