The aim of this study is to present new data for a better understanding of the anatomic correlation of these two notches.

This study included 32 nasal cavities (16 individuals) with external nasal dilator strip (Breath Right®) and after decongestion (0.05% oxymetazoline chloride applied as an aerosol spray);

Acoustic rhinometry is more accurate in the anterior portion of the nasal cavities, from the nostril to the nasal valve (NV), the most important site of nasal obstruction. Literature presents different opinions regarding the anatomical correlation of the two notches at the beginning of the rhinogram curve in normal adult Caucasian individuals.

This prospective study included 32 nasal cavities under the following conditions: 1st - basal condition; 2nd - with external nasal dilator strip (ENDS) (Breath Right®); 3rd - after decongestion (0.05% oxymetazoline chloride applied as an aerosol spray); 4th - after decongestion with ENDS.

Inclusion Criteria:

• Adult, Caucasian

Exclusion Criteria:

• Allergies, sinusitis, nasal polyps, external nasal deformities congenital or acquired, obstructive nasal deviation and regular use of any drug.

32 nasal cavities of 16 normal adult Caucasian individuals