Computed tomography versus nasal endoscopy for the measurement of the internal nasal valve angle in Asians.
CONCLUSIONS
The internal nasal valve (INV) angle in Asians is 21.6 degrees +/-4.5 degrees and it is significantly larger than that of Caucasians. The reconstructed CT method has better reproducibility than the endoscopic method in measuring the INV angle.


OBJECTIVE
The INV is an area of interest for nasal surgeons due to its functional significance in rhinoplasty and septoplasty. This study was designed to evaluate the size of the INV angle in an Asian population by measuring the angle through reconstructed CT scans and nasal endoscopy.


METHODS
Thirty-eight ostiomeatal unit CTs and 24 endoscopic photos of patients who had minimal or no sinonasal problems were analyzed. CT images that had been reconstructed perpendicular to the acoustic axis and endoscopic photos were used to measure the INV angle. Each method was verified as to reproducibility and the angles measured by the two methods were compared.


RESULTS
The INV angle of the Asians measured by CT scan was 21.6 degrees +/-4.5 degrees . This value was significantly larger than that of the Caucasians, which has been reported to be 11.4 degrees +/-2.6 degrees (p<0.001). The INV angle measured endoscopically was 19.3 degrees +/-3.6 degrees . Reproducibility of the reconstructed CT method was good (p<0.001), while the reproducibility of the endoscopic method was poor (p=0.093). The correlation between the two methods was also poor (p=0.107).
Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University, Boramae Hospital, Seoul, Korea.
Myung-Whan
MW
Suh
Hong-Ryul
HR
Jin
Ji-Hoon
JH
Kim
D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D044466:Asian People; D004724:Endoscopy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D009300:Nasal Septum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D044465:White People