Intervention
mouth-breathing
All patients were informed about the standard general anesthesia and perioperative management process. The participants in the education group (group E) received simulated mouth-breathing training with a nasal clip. The training involved a 30-minute session in which an experienced board-certified anesthesiologist (YJB) provided an in-depth education about mouth breathing. The decision of a 30-minute session was based on the previous studies [
Schematic drawing of preoperative simulated education and training with nasal clip