Effect of the external nasal dilator on nasal minimal cross-sectional areain Orientals as assessed by acoustic rhinometry

Objective: This study aimed to evaluate the effect of the external nasal di lator 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 rhin ometry 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 sig nificant increase of 0.10 cm(2) (SD = 0.16) or a 17% increase in the minima l cross-sectional area of the 50 nasal cavities after application of the ex ternal 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 cm(2), SD = .27, or 16% ; Wilcoxon's matched-pairs signed rank test, p = .0032). Conclusions: The external nasal dilator results in an increase in the minim al cross-sectional area of the nasal airway in Orientals.