Definition of Nasal Valve Location and Classification of Nasal Valve Stenosis in Computed Tomography

Recently, there has been confusion about the definition of nasal valve stenosis. To resolve this, it is necessary to establish clearly the location of the nasal valve and the definition of nasal valve stenosis. When scrolling the axial view from the top to the bottom, the angle between the upper lateral cartilage and the septum gradually increases, and the vertex becomes rounded. When the lower lateral cartilage is reached, the ceiling of the nasal cavity suddenly becomes higher, so the section immediately before it can be defined as the nasal valve. Nasal valve stenosis is classified as follows. If the difference between the diameters of the narrow and wide nasal valves is less than 1:3, it is normal, whereas if the difference is larger but some space is observed, it is partial stenosis, and if no space is observed, it is complete stenosis.