Breathing patterns significantly influence oral and facial structures. This article explores the relationship between mouth breathing and dental alignment, specifically addressing its connection to overbites.
Understanding Overbites and Mouth Breathing
An overbite, also known as a deep bite or Class II malocclusion, occurs when the upper front teeth significantly overlap the lower front teeth. While a minor overlap is normal and necessary for proper dental function, an excessive overlap can lead to various problems. This condition differs from an overjet, where the upper teeth protrude horizontally.
Mouth breathing is primarily inhaling and exhaling air through the mouth instead of the nose. It often results from obstructed nasal passages due to factors like allergies, chronic colds, sinus infections, enlarged tonsils or adenoids, a deviated septum, or nasal polyps. Sometimes, it can become a habit even after the initial obstruction resolves.
The Developmental Impact of Mouth Breathing
Chronic mouth breathing significantly influences craniofacial development, especially in children, potentially leading to or worsening an overbite. The tongue’s resting position is central to this. With nasal breathing, the tongue naturally rests against the roof of the mouth (palate), providing gentle pressure that guides proper upper jaw (maxilla) growth.
When an individual consistently breathes through their mouth, the tongue often drops to a lower position in the mouth, failing to exert this upward pressure on the palate. This lack of support can lead to a narrow upper jaw and a high, arched palate. A narrow upper jaw can then restrict space for the teeth, potentially causing crowding and impacting the alignment of both upper and lower teeth.
Altered jaw development can cause the lower jaw (mandible) to position backward or rotate downward, increasing an overbite. This change also affects facial muscle development and overall facial shape, sometimes leading to “long face syndrome” or “adenoid facies,” characterized by a longer, narrower face. Such structural changes can further encourage mouth breathing.
Wider Implications of Chronic Mouth Breathing
Beyond dental and facial structure, chronic mouth breathing is associated with other health and oral issues. A consequence is dry mouth (xerostomia), as constant airflow reduces saliva production. Saliva is essential for neutralizing acids, washing away food particles, and protecting against bacteria, so its reduction increases the risk of dental cavities, gum disease, and bad breath.
Chronic mouth breathing also negatively impacts sleep quality. It is linked to snoring and can worsen conditions like obstructive sleep apnea, where breathing repeatedly stops and starts during sleep. Poor sleep can lead to daytime fatigue, irritability, and difficulty concentrating, particularly in children.
The Importance of Nasal Breathing
Nasal breathing is the healthier method of respiration, offering several advantages for overall well-being and proper craniofacial development. Air passing through the nose is naturally filtered, warmed, and humidified before reaching the lungs. This process protects the respiratory system and enhances oxygen absorption.
Nasal passages also produce nitric oxide, a gas that aids in widening blood vessels, improving oxygen circulation. For dental and facial development, nasal breathing supports the tongue’s correct resting position against the palate. This proper tongue posture guides upper jaw growth and promotes optimal teeth alignment, contributing to healthy facial development. Addressing the underlying causes of mouth breathing is important for mitigating associated oral and health challenges.