Investigation of the Source of Snoring Sound by Drug-Induced Sleep Nasendoscopy

Objective: To investigate the source of snoring sound in patients with simple snoring (SS) and different degrees of obstructive sleep apnea syndrome (OSAS) in order to provide a basis for the surgical treatment of snoring. Methods: Fifty-two patients with either SS or OSAS (with an apnea-hypopnea index ≤40) underwent drug-induced sleep nasendoscopy (DISN). Vibration sites in the pharyngeal cavity were observed. Results: Vibration of the soft palate, pharyngeal lateral wall, epiglottis, and tongue base appeared in 100, 53.8, 42.3, and 26.9% of the patients, respectively. The source of snoring sound was divided into two types: palatal fluttering only (type I) and multisite vibration (type II). The latter was divided into 3 subtypes: palatal fluttering with epiglottis vibration (type IIa), palatal fluttering with lateral wall vibration (type IIb), and palatal fluttering with vibration of the lateral wall, epiglottis, and tongue base together (type IIc). The distribution of type I snoring was the highest in SS patients. Type IIb was more common in patients with medium and severe OSAS. Type IIc was most common in patients with severe OSAS. Conclusion: The source of snoring sound is diverse, with SS and OSAS patients showing different features. DISN is a very effective method of identifying the snoring source.