ACOUSTIC RHINOMETRY IN PRESCHOOL-CHILDREN

Acoustic rhinometry was performed in 35 normal nose-breathing children between 3 and 6 years. The average cross-sectional areas at the nasal valve, at the anterior end of the turbinates, and in the nasopharynx were 0.34+/-0.06 cm2, 0.35+/-0.08 cm2 and 1.37+/-0.48 cm2 respectively . The average minimal cross-sectional area was 0.29+/-0.06 cm2. The mi nimal cross-sectional area was located at the nasal valve in 14 and at the anterior end of nasal turbinates in 21 of the 35 children. As wou ld be expected, the cross-sectional areas at different sites of the na sal cavity increased with increasing age of the children. But, whereas the minimal cross-sectional area increased by 0.024 cm2 per year, the nasopharyngeal cross-sectional area increased by 0.20 cm2 per year. N o significant differences were found between boys and girls. Measureme nts of the posterior nasal and nasopharyngeal cross-sectional areas we re unreliable, whenever the minimal cross-sectional area was less than 0.2 cm2. Furthermore, assessment of the nasopharynx may be difficult because of involuntary movements of the soft palate.