The first report of using endoscopy to evaluate the structure of the internal nasal valve and the measurement of internal nasal valve angle value in Vietnamese people

The objective of this work was to investigate the structural formations and angle of the internal nasal valve (INV) by using nasal endoscopy. A cross-sectional-description study was conducted on one hundred and thirty-nine students of the University of Medicine and Pharmacy without the complaint of chronic nasal obstruction. They were examined the internal nasal areas by using endoscopy two times: before spraying decongestant, and after 15-30 minutes spraying of the decongestant into the nasal cavity to identify the types of the internal nasal valve according to Miman’s classification. The nasal valve angle value was determined by using Autocad software version 2007. The study was done at Can Tho University Hospital. Sharp angle type accounted for 32.01%, blunt angle type accounted for 12.23%, convex caudal border type accounted for 5.04%, concave caudal border type accounted for 5.04%, angle occupied by the septal body accounted for 34.17%, and twisted caudal border type accounted for 11.51% in our study, the average angle of 26°.8 ± 9°.28, with the smallest angle being 9° and the largest angle being 51°. When comparing the rate of internal nasal valve formation for each time in our study and that of Miman, we recognized that there is a difference among rates. Our nasal angle values were similar to those of Asians and different from those of Caucasians. By using endoscopy, we can easily determine the morphology of the internal nasal valve and measure the angle value of the internal nasal valve by using Autocad software version 2007.