Age and gender effects on nasal respiratory function in normal subjects.

One hundred and ninety-seven normal individuals between the ages of 5 and 73 years were evaluated to determine nasal resistance, nasal cross-sectional area, and respiratory mode during quiet breathing. Subjects were categorized into three age groups. Nasal resistance and respiratory mode were directly determined using posterior rhinomanometry and the SNORT technique, respectively. Nasal cross-sectional area was estimated using the hydrokinetic equation. Results indicated significant effects of age on all variables; significant gender differences were found for respiratory mode. Weak correlations were found between respiratory mode and nasal resistance. The results are presented as normative data on nasorespiratory characteristics to facilitate diagnostic and treatment decisions relative to individuals with normal morphology as well as to patients with craniofacial anomalies. A fundamental issue of both clinical and theoretical importance arising from the study pertains to the definitions of normality and impairment.