The normal ranges of selected acoustic rhinometry parameters depending on age and sex-component of standarization in nasal provocation test

Introduction
Acoustic rhinometry is a non-invasive method of measuring intranasal spaces. As one of the objective techniques for nasal patency, it plays a critical role in evaluating the nasal allergen challenge. Aim: To establish the typical ranges of selected AR parameters for age and sex.

Material and methods
The study was conducted in a group of 583 randomly selected subjects (329 females and 254 males). Acoustic rhinometry was done before and 15 min after a two-time application of 0.1% solution of the decongestant xylomethazoline. The evaluated AR parameters (the cross-sectional area 1 (CSA-1) at the level of the isthmus nasi and the distance between the external nares and the isthmus nasi (dCSA-1)) were measured separately for both nasal cavities. Another evaluated parameter was the mean CSA measured 3 cm beyond CSA-1 on the AR curve (CSA-3).

Results
The site of the minimum CSA on the acoustic rhinometry curve in the study group was the second notch on the acoustic rhinometry curve (CSA-1), corresponding to the nasal isthmus. With increasing age of the subjects, we observed a systematic increase in nasal spaces. The difference between sexes reached statistical significance at the ages of 17 years and older.

Conclusions
The evaluated males show larger nasal cavity volumes than females. The difference between the sexes reaches statistical significance at older ages.