Figure 4. Nasopharyngolaryngoscopy findings of the same patient reported in Figure 3 (snoring severity, 7; snoring index, 399.0 events/h) in different sleep positions.

(A) While in supine (sniff) position, the patient’s retropalatal space easily collapsed from the stationary phase to the Müeller’s phase. (B) While in lateral position, the retropalatal space was relatively stable between the two phases. (C) While in supine (sniff) position, the retroglossal space collapsed in a relatively easily manner from the stationary phase to the Müeller’s phase. (D) While in lateral position, the retroglossal space was widened and stable between the two phases.