Breathing seems like something that happens automatically and without consequence for oral health. But the route of breathing whether nasal or oral makes a significant difference to oral tissue health particularly over the years and decades of a lifetime.
What nasal breathing does for the mouth
Nasal breathing filters, humidifies, and warms air before it reaches the oral cavity. More importantly from an oral health perspective breathing through the nose keeps the mouth relatively closed maintaining an environment that saliva can effectively coat and protect. The salivary film on oral tissues is their primary defense mechanism. Antimicrobial proteins, buffering capacity, and moisture all depend on saliva covering tissue surfaces adequately.
What mouth breathing does instead
When air flows continuously through the open mouth it evaporates saliva from the anterior oral tissues particularly the front teeth and the gingiva surrounding them. For habitual daytime mouth breathers this evaporative drying continues for many hours each day. The consequences: the anterior gum tissue tends to become chronically inflamed and swollen, plaque accumulates on dry surfaces more readily, and cavity risk increases on anterior tooth surfaces.
Developmental effects in children
In children the consequences of chronic mouth breathing are more significant because the facial skeleton is still developing and is influenced by functional forces. The tongue normally rests against the palate during nasal breathing providing functional pressure that shapes the palatal arch upward and outward during development. In mouth breathers the palatal arch narrows without the normal tongue pressure. The result can be a high-narrow palate and crowded upper teeth that subsequently require orthodontic treatment. Mouth breathing in children is one of the most common contributors to orthodontic problems.
Why it happens and how to address it
Adults develop habitual mouth breathing from nasal obstruction due to allergic rhinitis, deviated septum, nasal polyps, or enlarged turbinates, or from sleep apnea. Addressing the nasal obstruction is the primary intervention. Treating allergic rhinitis with appropriate medication or seeing an ENT for anatomical obstruction that might be surgically correctable. Myofunctional therapy has evidence in children and some in adults for improving nasal breathing habits.
Educational content. If you suspect chronic mouth breathing is affecting your oral health see a dentist and consider an ENT evaluation for nasal obstruction.
