For people who struggle to breathe through their nose while sleeping, mouth breathing is the only alternative. But chronic ‘mouth breathers’ may not only be aggravating obstructive sleep apnea, they may also be undoing any effectiveness of continuous positive airways pressure (CPAP) treatment.
The airway performs best when breathing is practised consistently through the nose. Nose breathing strengthens the muscles of the upper airway, including those that line the throat. Obstruction in the nose, such as nasal congestion, can lead to increased mouth breathing.
Persistent mouth breathing may cause changes in the airway’s anatomy over time when the muscles of the jaw relax to allow the mouth to be open. This can cause the face to become elongated, especially during childhood, when the jaw and facial structure is not fully developed.
The tissues lining the nasal passage may also become swollen with the vibration of snoring, which may cause the nasal passage to collapse and further close, leading to further difficulty in breathing through the nose, so mouth breathing occurs.
Although mouth breathing is a common characteristic among those with sleep apnea, many will find that sufficient airflow delivered via CPAP can open up the nose.
Mouth breathing doesn’t cause snoring or sleep apnea, yet it can aggravate it, especially if the structure of the jaw means the tongue is predisposed to falling back into the throat during sleep.
Nasal congestion is a major cause of mouth breathing, and nasal obstruction can make nose breathing difficult. It is important to determine the reason behind nasal congestion. Nasal congestion can also be caused by narrow and constricted upper and lower jaw and narrow nasal cavities. A stuffy nose can aggravate soft palate and tongue collapse when in deep sleep due to muscle relaxation. With more obstruction, more stomach juices are suctioned up into the throat and nose, causing more swelling and more nasal congestion.
Mouth breathing can lead to a reduction in the effectiveness of CPAP treatment. CPAP delivers the constant flow of air, which keeps the upper airway open so breathing is easier. If the mouth falls open while the air is being delivered through your nose via a mask, it will escape. This can be an uncomfortable sensation and can cause a dry mouth. When the air escapes, the effectiveness of CPAP treatment is reduced.
CPAP users need to be able to breathe through the nose without discomfort. There are several ways to prevent mouth breathing while using CPAP, including treating the nasal congestion with oral medication or a nasal spray containing nasal steroids, and considering surgery if you have a deviated septum. Breathing through the nose can have many positive effects on the body, including regulating the volume of air breathed, so that it can effectively match the body’s oxygen needs.
Nose breathing encourages good facial development and straight teeth. A closed mouth – with the tongue in the roof of the mouth for most of the time – can help the jaw grow enough to accommodate all the teeth. Mouth breathing also causes the gums to dry, increasing the acidity in the mouth, which encourages cavities and gum disease.
How to prevent mouth breathing whilst using CPAP
• Determine the reason behind mouth breathing, such as nasal obstructions.
• Check your CPAP mask. An ill-fitting CPAP mask that is too big or small can cause leaks and may lead to mouth breathing.
• Find a mask that fits well – if you are trialing CPAP, it is important to ask your CPAP provider to try different masks and determine which is the most comfortable.
• If air is leaking from the mouth, one possible solution is to try a mask that covers both the nose and mouth or one that delivers the air directly into the mouth.
• Use a heated humidifier, which will keep the nose, mouth, and throat moist.
• Consider using a chin strap to keep the mouth closed. This often corrects mouth breathing while using CPAP.
• Old equipment should be checked, and it may be useful to have a repeat sleep study to ensure the CPAP equipment is being used correctly. As the equipment ages, the pressure that is delivered may wane through
leaks or other problems.
• Consider other interventions and alternative therapies including position therapy. Surgery may be necessary as a last resort.