Most of us don't give much thought to how we breathe and how the way we breathe can impact our oral health. While the nose is designed for breathing, many people habitually breathe through their mouth instead. This seemingly innocuous habit can lead to a cascade of dental problems that might surprise you. Here are some you should be aware of. 

The Dry Mouth Dilemma

When you breathe through your mouth, especially during sleep, you're exposing your oral cavity to constant airflow. This creates a condition called xerostomia, commonly known as dry mouth(1).

As Dr. Michael J. Wei, a cosmetic dentist, explains, "Breathing through the nose helps filter, humidify and warm the air before it enters the lungs(2)." In contrast, mouth breathing bypasses this natural filtration system and leaves your mouth parched.

But why is dry mouth a dental concern? Saliva plays a critical role in maintaining oral health. It:

• Contains minerals that help remineralize tooth enamel

• Neutralizes acids produced by bacteria

• Washes away food particles and bacteria

• Provides a protective coating for your teeth and gums

Without adequate saliva, your mouth becomes an ideal environment for bacterial growth, leading to several dental issues.

Increased Risk of Cavities and Gum Disease

The relationship between mouth breathing and dental decay is strong. In fact, some dental experts consider mouth breathing the number one cause of cavities—even ahead of poor diet or inadequate dental hygiene(3).

When saliva production decreases due to mouth breathing, the pH of your mouth drops into the acidic zone(4). This acidic environment promotes bacterial growth and accelerates tooth decay. The protective minerals in saliva can't effectively remineralize your teeth, making them more vulnerable to cavities.

Additionally, the dry environment created by mouth breathing can lead to inflamed gums, increasing your risk of gingivitis and periodontal disease. Chronic mouth breathing is often associated with red, swollen gums that bleed easily, the first signs of gum disease(5).

Impact on Facial and Dental Development

For children, the consequences of mouth breathing extend beyond decay and gum disease. Numerous studies have shown that mouth breathing can alter facial growth and development, particularly during critical growth periods.

According to research published in the journal "Children," mouth breathing in young people can lead to (6):

• A longer face with increased lower facial height

• A retrognathic (set-back) mandible

• Narrower dental arches

• Higher incidence of Class II malocclusion (overbite)

• Increased likelihood of posterior crossbite

• Development of an anterior open bite

These changes occur because mouth breathing alters the resting position of the tongue and the balance of forces exerted on the developing jaws and teeth.

Additional Dental Complications from Mouth Breathing

Beyond decay and gum disease, mouth breathing contributes to several other dental issues that can be both uncomfortable and costly to address.

Teeth Grinding and Clenching

Many mouth breathers also suffer from bruxism (teeth grinding). When you breathe through your mouth during sleep, it's often associated with sleep-disordered breathing or mild sleep apnea. The body's natural response to airway obstruction is to grind or clench the teeth, which helps force air into the airways(7).

While this is a life-saving reflex, it comes at a cost to your dental health. Grinding leads to:

• Premature enamel wear

• Tooth fractures and chips

• Increased tooth sensitivity

• Jaw pain and TMJ disorders

• Gum recession

Compromised Dental Restorations

Mouth breathing doesn't just affect natural teeth—it can also compromise dental work. Restorations such as fillings, crowns, and bridges are all affected by the dry, acidic environment created by mouth breathing.

Research shows that reduced salivary flow can accelerate the deterioration of dental materials and weaken the bond between restorations and tooth structure(8). This leads to:

• Shorter lifespan of dental work

• Increased risk of secondary decay around fillings

• Greater chance of restoration failure

• More frequent and costly replacement needs

For patients who have invested in cosmetic dentistry or extensive restorative work, persistent mouth breathing can significantly undermine those investments over time.

Increased Risk of Oral Infections

The dry oral environment created by mouth breathing reduces your natural defense mechanisms against infections. Without adequate saliva, you're more susceptible to(9):

• Oral thrush (a fungal infection)

• Bacterial infections of the gums and soft tissues

• Chronic halitosis (bad breath) resistant to traditional oral hygiene

Orthodontic Complications

For those undergoing orthodontic treatment, mouth breathing can complicate and extend treatment time. It can contribute to(10):

• Relapse after orthodontic correction

• Difficulty achieving ideal tooth alignment

• Greater challenges in correcting certain bite issues

Long-term Consequences

Over time, the dental effects of chronic mouth breathing can lead to serious consequences. Studies have linked persistent mouth breathing to(11):

• More frequent need for dental restorations

• Higher likelihood of tooth loss

• Chronic oral pain conditions

• Reduced success rates for dental procedures

Your mouth was designed for eating, tasting, and talking. Your nose was designed for breathing. When these systems function as intended, your dental health thrives(12). Making the switch to nasal breathing is one of the most impactful changes you can make for your long-term dental health and comfort.

References

1. WebMD. (2023). "What to Know About Mouth Breathing." Retrieved from uploaded documents.
   
   

2. Shaw, S. (2024). "Does mouth taping for sleep actually work? We asked healthcare experts." CNN Underscored.
   
   

3. McKeown, P. "Every night, after my wife and I say goodnight, I reach for a roll of mouth tape in the drawer of my bedside table." Ask The Dentist.
   
   

4. McKeown, P. "The Oxygen Advantage: The Simple, Scientifically Proven Breathing Techniques for a Healthier, Slimmer, Faster, and Fitter You."
   
   

5. Inönü-Sakalli, N., et al. (2021). "Comparative Evaluation of the Effects of Adenotonsillar Hypertrophy on Oral Health in Children." BioMed Research International.
   
   

6. Feştilă, D., et al. (2025). "Oral Breathing Effects on Malocclusions and Mandibular Posture: Complex Consequences on Dentofacial Development in Pediatric Orthodontics." Children, 12(1), 72.
   
   

7. Harari, D., et al. (2010). "The Effect of Mouth Breathing versus Nasal Breathing on Dentofacial and Craniofacial Development in Orthodontic Patients." Laryngoscope, 120, 2089-2093.
   
   

8. Milanesi, J., et al. (2018). "Variables Associated with Mouth Breathing Diagnosis in Children Based on a Multidisciplinary Assessment." CoDAS, 30.
   
   

9. Nicolò, A., et al. (2025). "Breathing in sport and exercise: physiology, pathophysiology and applications." Frontiers in Physiology.
   
   

10. Chambi-Rocha, A., et al. (2018). "Breathing Mode Influence on Craniofacial Development and Head Posture." Journal of Pediatrics, 94, 123-130.
    
    

11. Lin, L., et al. (2022). "The Impact of Mouth Breathing on Dentofacial Development: A Concise Review." Frontiers in Public Health.
    
    

12. McKeown, P. (2024). "ButeykoClinic instructor Training: Breathing Exercises Manual."