Using sagittal plane images from consecutie patients, the mean nares-cricoid (NC) distance, upper incisor-cricoid (IC) distance, and their mean differences were determined.

• 从患者获得的矢状面连续影像、平均鼻孔-环状软骨间距、上切牙-环状软骨间距、并确定它们的平均差。