Normal nasal airway resistance in noses of different sizes and shapes

Measurement of nasal airway resistance is becoming a common clinical technique. Accurate definition of the normal range of airflow is critical for maximal usefulness of this technique. Since typical nasal size and shape vary greatly with ethnic background, different norms for different ethnic groups may be appropriate. Nasal airway flow and resistance and external nasal size and shape were measured in 130 asymptomatic subjects (52 black, 56 white, and 22 Hispanic). Nasal length, width, columellar length, and nasolabial angle were similar for whites and Hispanics, but both groups differed significantly from blacks--even when changes attributable to biologic aging were factored out. In spite of these differences, there was no significant difference in any nasal airflow or resistance parameter among groups, suggesting that currently used airflow and resistance standards are valid for these three different ethnic groups.