[Determinations of nasal effective cross-sectional area in 1100 normal subjects]

Generally speaking, the NECA represents the narrowest site of the nasal airway and mirrors the site of the nasal valve in normal subjects. So the NECA is the basic element in producing and determining the NAR. A flow-pressure technique with software was developed to measure the NECA in 1100 normal subjects. The normal values values of NECA in children and adults were established to be 0.40 +/- 0.12cm2 and 0.52 +/- 0.17cm2 respectively. There was a significant positive correlation between the age increase and NECA augmentation in children (r = 0.649, P < 0.01), and NECA grew at a rate of 0.022 cm2 per year from 5 to 16 years of age, but revealed some peculiar characters in different phases of pediatric development. From 20 years of age the change of NECA began to take a stable course, but had a trend to crawl up with ageing. There were no significant differences of NECA between the male and female in different age groups. It was also noted that there was a negative linear relationship between ipsilateral NECA and NAR, and also so between the NECA of both sides combined and total NAR. From the findings above, we propose that NECA could be a quantitative and objective parameter for assessing the nasal airway impairment.