It is inevitable that a child with a blocked nose will breathe through his mouth. Mouth breathing children often develop poor facial structures such as undeveloped chins, narrow faces and nostrils, crooked teeth, sunken cheeks and eyes, and larger noses. When a growing child keeps his mouth closed, the tongue correctly rests in the roof of the mouth, creating a U-shaped top jaw. In other words, the shape of the top jaw is the tongue. A mouth breathing child is unable to rest his tongue in the roof of the mouth. As a result, his tongue rests midway or on the floor of the mouth. The result is a narrow and undeveloped top jaw that is set back on the airways, creating smaller airways and an increased risk of developing lifelong sleep apnoea.
In the words of California-based dentist Dr. Raymond Silkman, “The most important orthodontic appliance that you all have and carry with you twenty four hours a day is your tongue. People who breathe through their nose normally have a tongue that postures up into the maxilla (the top jaw). When the tongue sits right up behind the front teeth, it is maintaining the shape of the maxilla (top jaw) every time you swallow. Every time the proper tongue swallow motion takes place, it spreads up against the maxilla (top jaw), activating it and contributing to that little cranial motion. Individuals who breathe through their mouths have a lower tongue posture and the maxilla does not receive the stimulation from the tongue that it should.”
Posnick et al. writes that, “a long-standing forced mouth breathing pattern with open mouth posture is known to impact on maxillo-mandibular (Jaw) growth and be a major contributing factor to developmental jaw deformities.” This is further discussed by Ahn in a paper entitled, “Treatment of obstructive sleep apnoea in children.” Ahn notes that, “the impairment of nasal breathing with increased nasal resistance has a well-documented negative impact on early childhood maxilla-mandibular development, making the upper airway smaller and might lead to adult OSA.”
In a study of children with a long history of habitual snoring and obstructive sleep apnoea, a neurological clinical examination showed that snoring started very early in childhood, at 22.7 months, while apnoea onset was 34.7 months. The authors of the study noted that, “23% of children showed a failure to thrive.” Children with sleep apnoea showed different craniofacial changes with the development of a narrower vertical face and reduced upper airway space. The study concluded that, “these results suggest that oral (mouth) breathing, that is present in sleep apnoea patients, is responsible of different cranio-facial anomalies.”
Finally, a study of 26 children was conducted to detect the presence of early bone craniofacial modifications in young children with a long history of habitual snoring. The study found that upper airway obstruction during sleep is associated with mild but significant craniofacial modifications in children complaining of habitual snoring.