Effect of the external nasal dilator on nasal minimal cross-sectional area in orientals as assessed by acoustic rhinometry.

Objective: This study aimed to evaluate the effect of the external nasal dilator on the dimension of the nasal valve in Orientals.
Design: A cohort study of normal subjects.
Setting: Academic institution.
Methods: The nasal fossae of normal subjects were assessed by acoustic rhinometry before and after application of the external nasal dilator.
Main Outcome Measures: The minimal cross-sectional area of the nasal fossae and the total cross-sectional area of the nose.
Results: Nasal fossae of 25 normal subjects were evaluated. There was a significant increase of 0.10 cm2 (SD = 0.16) or a 17% increase in the minimal cross-sectional area of the 50 nasal cavities after application of the external nasal dilator (Wilcoxon's matched-pairs signed rank test, p = .0001). A significant increase in the total minimal cross-sectional area for the whole nose after application was also present (0.19 cm2, SD = .27, or 16%; Wilcoxon's matched-pairs signed rank test, p = .0032).
Conclusions: The external nasal dilator results in an increase in the minimal cross-sectional area of the nasal airway in Orientals.