Mouthguard Position Influencing Strength and Posture

KEY POINTS TO COVER (Outline)

• Audience: field and court athletes, lifters, coaches, sports dentists, physiotherapists, strength staff, and parents of youth athletes.

• Plain-English idea: jaw position and occlusal contact can change muscle activation and stability.

• Mechanisms: concurrent activation potentiation (CAP), trigemino‑cervical links, intra‑oral proprioception.

• What studies show: mixed acute effects on strength/power; variable results for balance and endurance.

• Posture link: craniocervical posture associations with occlusion in select groups; evidence quality varies.

• Balance data: center‑of‑pressure and sway metrics with and without mouthguards or splints.

• Strength/power details: EMG, rate of force development, interocclusal distance, clench instructions.

• Airway/ventilation: effects of jaw‑repositioning devices and vented guards.

• Selection guide: stock vs boil‑and‑bite vs custom; thickness and fit per sports dentistry guidance.

• Positioning and bite setting: practical cues; when to avoid over‑opening.

• Action protocol: how to field‑test a guard for your sport.

• Sport‑specific notes and compliance factors.

• Risks, side effects, and red flags.

• Critical perspective: sample sizes, blinding, placebo, heterogeneity, and null results.

• Rules and tech: governing‑body guidance and instrumented mouthguards.

• Human side: feel, confidence, routine.

• Summary with call‑to‑action and a short disclaimer.

 

Mouthguard position influencing strength and posture sounds like a locker‑room myth until you feel what happens when you bite down at the right moment. This article walks athletes, coaches, and clinicians through what is known, what is not, and how to test mouthguards in a clean, practical way. The core idea is simple. Jaw position alters how teeth meet (occlusion). That contact sends sensory signals through the trigeminal nerve. Those signals can influence neck and trunk muscles that help you brace and move. Studies call one part of this chain concurrent activation potentiation, or CAP. CAP means a strong remote contraction, like jaw clenching, can transiently increase force or rate of force development in a lift or jump (1).

 

Let’s ground the mechanism before any claims. When you clench, periodontal and muscle receptors fire. They feed into brainstem circuits connected with the trigemino‑cervical complex. Research shows reflex connections from trigeminal input to neck muscles like the sternocleidomastoid and trapezius. Long‑latency trigemino‑cervical reflexes appear reliably in healthy adults. Recordings capture neck muscle responses after trigeminal stimulation, which confirms a pathway that can change cervical muscle activity (2–5). You do not need neuroanatomy to use this. You only need to know that a crisp bite can stiffen the system upstream of your barbell or sprint.

 

What does performance research say? Results vary by device, task, and instruction. In a countermovement jump trial, jaw clenching increased rate of force development by 19.5% and reduced time to peak force by 20% versus a no‑clench condition, with no change in peak force (n=16; track and field athletes) (1). In contrast, a randomized, within‑subject study of 21 recreationally trained men found no improvement in CMJ height or bench‑press 1RM when wearing a boil‑and‑bite “performance” mouthpiece without clench instructions (p≥0.08) (6). Two points emerge. First, clenching matters. Second, “wearing a device” without clear motor intent may do little.

 

Zoom out to reviews. A 2021 systematic review pooled acute trials on bite‑aligning mouthguards and reported small, task‑specific benefits for strength and power in trained populations, with heterogeneity in protocols and devices (search through May 2021; 13 studies included) (7). A 2023 meta‑analysis covering 41 studies and 852 athletes concluded that mouthguards, especially custom models, tended to show small improvements in athletic performance versus no guard, but effects were inconsistent and largest in isometric or explosive tasks (8). Real‑world takeaway: some athletes register a small bump in force or rate metrics. Others do not. Expect variability.

 

Posture and balance sit in a greyer zone. Among adults with temporomandibular disorders, a 2022 systematic review suggested occlusal splints might improve measures of spinal posture, but it flagged weak postural assessment methods and risk of bias (9). For balance in athletes, a basketball study with customized guards showed better center‑of‑pressure control after repeated use rather than a single session, hinting at a learning or adaptation effect (n=23; three conditions; 8‑week follow‑up) (10). A 2023 study equalizing occlusal contact reported improved postural control across untrained adults and trained groups using center‑of‑pressure displacement metrics, again with small effects and careful guard adjustment (11). Yet, a 2024 rugby study that used a sport‑oriented perturbation platform found jaw‑clench with a mouthguard increased isometric quadriceps strength and early RFD but did not change dynamic balance variables (n=13; randomized MB vs NB) (12). The safest statement is narrow: mouthguard‑jaw clenching can boost immediate force output; balance benefits are task‑ and protocol‑dependent and often small.

 

Airway and endurance claims need precision. A medicine‑and‑sports exercise trial from 2006 measured oxygen uptake and ventilation during submaximal and maximal exercise in 19 trained men across no guard, self‑adapted guard, and custom guard. It found no detrimental effect on VO2 or ventilation, so basic physiology stayed intact (13). A crossover study on lower‑jaw advancement splints during running found perceptual and biophysical shifts without clear oxygen‑uptake penalties; it used graded intensities and reported changes in blood lactate and ratings of exertion early in the protocol (14). A 2024 European Journal of Sport Science trial comparing three custom mouthguard designs reported no impact on cardiorespiratory variables but noted comfort differences (15–16). By contrast, a 2021 study on a self‑adapted guard showed reduced ventilation and a small hit to exercise capacity, suggesting poor fit can impair airflow (17). Fit and design matter. Vented channels, thickness, and how far the mandible is advanced can change feel and breathing. Test this in your sport, not just on a treadmill.

 

Selection matters as much as position. Stock guards protect teeth but fit loosely. Boil‑and‑bite guards are common but often end up thin after molding and trimming, sometimes leaving molars uncovered. Custom guards, fabricated by a sports dentist, provide retention, even occlusal contact, and predictable thickness. The Academy for Sports Dentistry recommends a minimum of about 3 mm thickness at key areas and a balanced occlusion to spread impact forces (18). The American Dental Association advises a properly fitted guard for any activity with dental‑injury risk, emphasizing retention and coverage and noting education and compliance as keys to protection (19). If you wear braces, you need orthodontic‑compatible designs. Avoid cutting the guard to “make it comfortable.” You remove the protection you paid for.

 

Positioning your bite is a separate step. Most strength or jump tests improve with a firm clench at the drive phase. That said, over‑opening the mouth increases occlusal vertical dimension and can reduce force transfer. Aim for light tooth contact at set‑up, then clench firmly only during the push, pull, or landing. Many studies did not standardize clench level, which explains scattered results. If you have a custom guard, ask the dentist to register a reproducible bite with even contacts. Consistency beats guesswork.

 

Want a practical testing plan? Establish a baseline in your training context. Across two weeks, complete three sessions with no guard and jaw relaxed. Record countermovement jump height and RFD if you have a force platform, or use a validated jump app plus an isometric mid‑thigh pull for peak force. Then test three sessions with your chosen guard in three states: no clench, submaximal clench, and maximal clench. Randomize the order. Keep warm‑ups identical. If possible, blind a coach to your condition and have them record the best of three attempts for each test. Track means and the smallest worthwhile change. If your RFD0–100 ms or peak force rises beyond normal day‑to‑day variability only in the clench conditions, you have a personal green light. If nothing moves, do not force it.

 

Rules and tech shape compliance. High‑school federations mandate mouthguards for football, field hockey, ice hockey, lacrosse, and for wrestlers with braces (20). The NCAA mandates guards in football. World Rugby and elite competitions have rolled out instrumented mouthguards that trigger head‑impact assessments when thresholds are exceeded. Leagues have adjusted protocols after early data‑transfer issues, but adoption is growing because the devices help medical staff spot dangerous collisions quickly (21–23). This does not change lift numbers, but it does change what you wear and how often you wear it.

 

Let’s talk risks and red flags. Poorly fitting guards can irritate gums, trigger a gag reflex, and increase salivation. Over‑the‑counter jaw‑repositioning designs can alter your bite if worn for long hours. People with active temporomandibular disorders can flare pain with hard clenching. If you develop joint clicking, morning jaw stiffness, ear pain, or headaches, stop the experiment and see a dentist or a clinician trained in TMD. Guards that hold the mouth open too far can feel short of breath during hard efforts. That is not “mental.” It is airflow and effort.

 

Critical perspective keeps claims honest. Many trials are small (n≈10–30), short (single session or a few weeks), and vary in guard type and instructions. Blinding is difficult because you know when a guard sits in your mouth. Expectancy effects exist. Some studies instruct maximal clench; others tell participants to perform “as normal.” That difference can decide the result. Reviews and meta‑analyses report small positive effects for strength or power with custom devices, but they also note heterogeneity, publication bias risk, and task specificity (7–8). Balance outcomes vary with test choice. Airway results hinge on design and fit. Use the data, but test your own use‑case.

 

The human side matters. Many athletes report a steadier “brace” and more confidence when the bite feels locked in. That feeling can improve intent and rhythm on a heavy attempt. Others dislike the mouth feel or speech changes and end up chewing the guard. Chewing ruins retention and thickness. Build a routine. Insert the guard after your general warm‑up. Rehearse your clench during the last easy set. Keep the guard clean. Replace it if it warps or thins.

 

Here is a simple decision path. If your sport mandates a guard, get a custom model and wear it. If you lift, sprint, or play non‑mandated sports and want to experiment, run the test plan above. If you see a reliable bump in RFD or peak force with a firm clench, consider using the guard for key sets or attempts. If you track no benefit or you notice airway or jaw symptoms, skip it. The goal is not a device. The goal is better performance and fewer dental bills.

 

Summary and next step. Jaw position and occlusal contact can influence strength output through CAP and trigemino‑cervical links. Evidence shows small, task‑specific benefits for some athletes, with mixed results for balance and endurance. Fit and clench instructions drive outcomes. Custom guards and even contacts help. Poorly fitted self‑adapted guards can impair ventilation. Test in your context, track the metrics that matter, and decide based on your data. If this was useful, share it with a teammate or coach, subscribe for future breakdowns, and send your results so we can compare notes.

 

Disclaimer. This article is for informational purposes only and does not constitute medical or dental advice. Mouthguard selection and occlusal adjustments can affect the temporomandibular joint and breathing. Consult a licensed dentist or physician before starting or changing any device use, especially if you have facial pain, jaw noises, orthodontic appliances, or respiratory conditions. Use guards according to sport rules and manufacturer guidance.

 

References

1. Ebben WP, Flanagan EP, Jensen RL. Jaw clenching results in concurrent activation potentiation during the countermovement jump. J Strength Cond Res. 2008;22(6):1850‑1854.

2. de Melo DLM, Nogueira‑Costa R, et al. Technical aspects of eliciting trigeminocervical and trigeminospinal reflexes in humans: a scoping review. Clin Neurophysiol Pract. 2024; (online ahead of print).

3. Hellmann D, et al. Anterior and posterior neck muscle activation during a unilateral jaw‑clenching task. J Oral Rehabil. 2012;39(5):377‑384.

4. Di Lazzaro V, et al. Trigemino‑cervical reflexes. In: Clinical Neurophysiology in Disorders of Consciousness. Elsevier; 2006.

5. Powell K, et al. Trigeminal nerve stimulation: a current state‑of‑the‑art review. Bioelectron Med. 2023;9(1):13.

6. Allen CR, Dabbs NC, Zachary CS, Garner JC. The acute effect of a commercial bite‑aligning mouthpiece on strength and power in recreationally trained men. J Strength Cond Res. 2014;28(2):499‑503.

7. Miró A, Buscà B, Aguilera‑Castells J, Arboix‑Alió J. Acute effects of wearing bite‑aligning mouthguards on muscular strength, power, agility and quickness in a trained population: a systematic review. Int J Environ Res Public Health. 2021;18(13):6933.

8. Cao R, et al. Influence of wearing mouthguards on performance among athletes: a systematic review and meta‑analysis. J Sci Med Sport. 2023;26(12):1150‑1159.

9. Ferrillo M, et al. Effects of occlusal splints on spinal posture in patients with temporomandibular disorders: a systematic review. Healthcare (Basel). 2022;10(5):896.

10. Nam HJ, et al. The effect of wearing a customized mouthguard on body posture and balance performance. Healthcare (Basel). 2020;8(3):274.

11. Takahashi M, et al. Equalization of the occlusal state by wearing a mouthguard contributes to improving postural control function. Appl Sci. 2023;13(7):4342.

12. Rizzato A, Dalla Costa VG, Bozzato M, Paoli A, Marcolin G. Concurrent activation potentiation improves lower‑limb maximal strength but not dynamic balance control in rugby players. Front Bioeng Biotechnol. 2024;12:1270322.

13. Bourdin M, Brunet‑Patru I, Hager P‑E, et al. Influence of maxillary mouthguards on physiological parameters. Med Sci Sports Exerc. 2006;38(8):1500‑1504.

14. Cardoso F, Monteiro AS, Vilas‑Boas JP, Pinho JC, Pyne DB, Fernandes RJ. Effects of wearing a 50% lower jaw advancement splint on biophysical and perceptual responses at low to severe running intensities. Life. 2022;12(2):253.

15. Karaganeva R, et al. The effects of custom‑made mouthguard design on physiological function, exercise performance and comfort. Eur J Sport Sci. 2024;24(10):1754‑1765.

16. Karaganeva R, et al. The effects of custom‑made mouthguard design on physiological function, exercise performance and comfort. Eur J Sport Sci. 2024; Epub ahead of print.

17. Lässing J, et al. Decreased exercise capacity in young athletes using self‑adapted mouthguards. Eur J Appl Physiol. 2021;121(7):1897‑1906.

18. Academy for Sports Dentistry. Position Statement on Athletic Mouthguards. Accessed 2025.

19. American Dental Association. Athletic Mouth Protectors (Mouthguards). Accessed 2025.

20. National Federation of State High School Associations (NFHS). Position Statement and Recommendations for Mouthguard Use in Sports. 2022.

21. Reuters. Super Rugby tweaks concussion mouthguard rules after technical issues. 2024.

22. The Times (London). Mouthguards that flash red after heavy impacts to be used at Women’s Rugby World Cup. 2025.

23. Reuters. Women’s Rugby World Cup players to wear mouthguards that light up on heavy impact. 2025.