Runner's Tooth Wear and Jaw Occlusion: The Overlooked Hidden Sports Injury

Introduction

A 2018 study published in the British Journal of Sports Medicine shocked the sports world: oral examinations of 35 endurance athletes found that the caries rate was as high as 50%, tooth erosion exceeded 40%, and the proportion of malocclusion was significantly higher than the general population. For runners, oral health is a severely neglected area. This article compiles the dental issues and protection strategies runners should know.

Why Are Runners’ Teeth Prone to Problems?

1. Sports Drinks and Energy Gels

• pH value around 2.5–4, more acidic than cola
• High sugar content, providing nutrients for oral bacteria
• Prolonged sipping in small amounts → sustained acidic environment in the mouth
• During marathon training, 5–10 energy gels may be consumed per week

2. Mouth Breathing and Oral Dryness

• Breathing volume increases 10–20 times during exercise
• Reduced saliva → loss of acid-neutralizing, antibacterial, and remineralizing functions
• Bacterial proliferation and accelerated acid erosion

3. Jaw Clenching While Running

• Unconscious clenching during sprints or uphill sections
• A marathon may involve tens of thousands of occlusal contacts
• Plus impact from the lower limbs transmitted to the temporomandibular joint
• Tooth wear, hypertrophy of masticatory muscles, TMJ disorders

4. Training Diet Patterns

• High carbohydrate intake (rice, noodles, bananas)
• Intermittent eating, frequent carbohydrate consumption
• Brushing immediately after training (more severe wear after acid erosion)

Common Oral Problems in Runners

Problem	Main Cause	Prevention
Caries (cavities)	Sugar + acid + bacteria	Dietary adjustment + fluoride
Tooth erosion	Acidic drinks, gastroesophageal reflux	Rinse mouth, use a straw
Tooth attrition	Running occlusion + bruxism	Occlusal splint
TMJ disorder	Overuse of masticatory muscles	Relaxation + occlusal splint
Gum recession	Aggressive brushing + periodontitis	Soft-bristled brush + floss
Xerostomia (dry mouth)	Mouth breathing + dehydration	Hydration + nasal breathing

Tooth Erosion vs. Attrition vs. Caries

• Erosion: Chemical destruction, caused by acid
• Attrition: Mechanical destruction, caused by occlusal friction
• Abrasion: Mechanical destruction, caused by brushing or foreign objects
• Caries: Acid produced by bacterial metabolism

Runners commonly face a “double attack” of erosion + attrition.

Self-Examination

• Whether tooth surfaces have turned yellow or translucent (enamel loss)
• Whether tooth edges have become thinner or shorter
• Whether there is sensitivity to hot or cold
• Whether the jaw is sore upon waking in the morning (nocturnal bruxism)
• Whether the temples often feel tense (hypertrophy of masticatory muscles)
• Whether there is a clicking sound when opening the mouth fully (TMJ)

How to Drink Sports Drinks Correctly

• Do not sip slowly and hold in the mouth: Reduce the duration of acidic contact with the oral cavity
• Use a straw: Liquid bypasses the front teeth
• Rinse with plain water after drinking: Neutralize acidity
• Brush 30 minutes later: Enamel is vulnerable during acid erosion; brushing immediately accelerates wear
• Consider diluting sports drinks for long-distance training

Choosing Energy Gels

• Prioritize formulas with a “neutral pH”
• Drink water and rinse after consumption
• Do not let energy gel remain attached to teeth for long periods
• Prioritize regular meals after training to reduce reliance on energy gels

Oral Care Before, During, and After Running

Before Running

• Brush 30–60 minutes beforehand
• Do not head out right after eating acidic foods
• Hydrate to avoid oral dryness

During Running

• Focus on nasal breathing (at moderate intensity)
• Prioritize water over sports drinks
• Be aware of unconscious clenching

After Running

• Rinse with water immediately
• Wait 30 minutes before brushing
• Use fluoride toothpaste
• Floss once daily

Managing TMJ (Temporomandibular Joint) Disorders

Symptoms:

• Limited mouth opening
• Clicking or locking
• Temple swelling and pain
• Ear fullness
• Headaches

Management:

• Self-massage of the masseter muscles (in front of the ears)
• Mouth-opening exercises (controlled in front of a mirror)
• Avoid hard foods (chewing gum, nuts)
• Remind yourself to “relax the jaw” during training
• Seek medical evaluation for severe cases; an occlusal splint may be needed

Regular Dental Check-ups for Runners

Examination	Frequency
General check-up + cleaning	Every 6 months
Full-mouth X-ray	Every 1–2 years
Occlusal assessment	Annually (especially for long-distance runners)
Tooth erosion assessment	Annually

Methods for Training Jaw Relaxation

• While running, remind yourself: “tongue against the palate, lips gently closed, teeth not touching”
• Check jaw status every kilometer
• At high intensity, breathe through the mouth to relax the jaw
• Perform 2 minutes of jaw massage after running

Practical Recommendations

• Use fluoride toothpaste twice daily, with sodium fluoride concentration of 1450ppm or higher
• Rinse immediately after long-distance training, brush 30 minutes later
• Invest in an electric toothbrush (with automatic pressure alerts)
• Complete a full oral examination at least once a year
• Watch for nocturnal bruxism; wear an occlusal splint if necessary
• Supplement vitamin D and calcium to support teeth and bones
• Quit smoking and betel nut chewing—these are the biggest killers of oral health

Conclusion

Runners focus all their attention on knees, ankles, and cardiopulmonary function, yet often overlook the mouth—“the body’s most frequently used entry point.” Good teeth not only affect diet and appearance but are also the foundation of long-term health. Incorporate oral care into your training plan, and you will find yourself running longer, healthier, and smiling brighter.

Related Reading

• Athletes’ Teeth Can’t Wait: From Sports Drinks and Mouth Breathing to Protection, Oral Health Explained in One Go
• Gastrointestinal Issues in Endurance Athletes: Solutions for Runner’s Diarrhea and Cycling Bloating
• Iron Deficiency and Sports Anemia in Female Runners: You May Not Know You’re Iron-Deficient
• Sports Anemia: The Impact of Long-Distance Running on Iron Levels