Mouth breathing

**Definition:** Breathing through mouth. Nasal obstruction may also necessitate mouth breathing, which itself can precipitate obstructive apnoea. Breathing through the mouth may also increase risk for OSA [obstructive sleep apnoea] by its effect on the tongue. The tongue forms the anterior wall of the oropharynx; both the supine posture and opening of the mouth tend to displace it posteriorly and encourage airway closure.

**Exclusions:** - Dry mouth