Mouth breathing can change the face, particularly during childhood growth and development. Nasal breathing is the intended method, filtering and humidifying air while promoting a correct resting posture for the tongue. When chronic oral breathing replaces this natural process, a different set of forces begins to shape the facial bones.
The Mechanics of Facial Growth
The development of the face is highly influenced by surrounding muscular forces, a concept known as facial plasticity. During childhood, when bones are actively growing, the face is shaped by the soft tissues, primarily the pressure from the tongue, lips, and cheeks. In ideal nasal breathing, the tongue rests gently against the roof of the mouth (hard palate). This constant internal pressure acts as a natural, outward-directed force, encouraging the upper jaw (maxilla) to grow wide and forward. This internal force balances the external pressure from the lips and cheeks, creating a harmonious growth pattern.
How Oral Posture Alters Craniofacial Structure
Chronic mouth breathing disrupts this balance by changing the tongue’s resting posture. To open the oral airway, the tongue drops from the palate to the floor of the mouth, resting low and forward. This downward movement removes the necessary upward and outward scaffolding needed for the maxilla’s proper development. Without the tongue’s internal support, the external buccinator muscles of the cheeks and lips dominate. These muscles exert an unopposed, inward pressure on the upper jaw, leading to compression and narrowing. This compression can result in a high, vaulted palate and insufficient space for adult teeth. The lower jaw (mandible) must also rotate downward and backward to accommodate the lowered tongue and maintain an open airway. This rotation increases the overall vertical dimension of the lower face, leading to a steeper facial angle and a less prominent chin profile.
Identifying the Aesthetic and Functional Changes
The mechanical alterations caused by chronic oral breathing result in features often described as “long-face syndrome” or “adenoid facies.” Visually, the face may appear longer and narrower than average, with a lack of development in the midface region. This underdevelopment can lead to flatter cheeks and less defined cheekbones. The rotation of the mandible contributes to a retruded chin and jawline, along with an increased lower facial height. Narrowing of the dental arch often causes dental crowding and misalignment, leading to issues like posterior crossbite or a Class II malocclusion. Other common visible signs include lip incompetence (the inability to comfortably keep the lips closed at rest) and sometimes a “gummy smile.” Functionally, these changes are linked to an increased risk of malocclusion and sleep-disordered breathing, such as obstructive sleep apnea.
Correcting Habitual Mouth Breathing
Addressing chronic mouth breathing requires identifying and treating the underlying cause, which is often an airway obstruction. Common obstructive causes include enlarged tonsils or adenoids, chronic allergies, or a deviated nasal septum. Consulting with an Ear, Nose, and Throat (ENT) specialist is often the first step to resolve these physical barriers. Once the airway is clear, or if the breathing pattern is purely habitual, specific therapies are used to retrain the oral and facial muscles. Orofacial myofunctional therapy involves personalized exercises designed to strengthen the tongue and facial muscles and establish a correct resting posture. The goal is to teach the individual to breathe through the nose and keep the tongue resting against the palate, which guides healthy growth. In growing children, orthodontic intervention can be used alongside muscle retraining. Appliances like palatal expanders can widen a narrow upper jaw, creating space for the tongue and correcting skeletal issues. Early intervention is the most effective approach, as facial structures are pliable and responsive to positive change during the formative years.