Dimensions and resistances of the human nose: racial differences.

Dimensions of the external nose and nostrils and nasal airflow resistances were determined in healthy, young Caucasian, Oriental, and Negro adults. Statistically significant variation between racial groups was found in nasal width and the differential between dorsi-ventral and transverse nostril diameters. Corresponding differences were found also in nasal airflow resistances of combined and separate nasal cavities in both the untreated and decongested state. Caucasian noses were leptorrhine, Negro noses were platyrrhine, and Oriental noses were of intermediate dimension. Mean nasal resistances of untreated noses were 0.129 Pa/cm3/sec in Negroes (N = 17), 0.146 in Orientals (N = 20), and 0.184 in Caucasians (N = 24), and differences were more marked when noses were decongested (P less than 0.05 in all cases). Ratios between resistances of untreated and decongested noses showed no statistical differences between racial groups, suggesting a similarity in the mucovascular component of resistances.