Open mouth posture and cross-sectional nasal area in young children.

A biracial sample of two-hundred ninety-six children were assessed for open-mouth posture (OMP) in the natural environment. In addition, rhinometry was performed on 288 of the youngsters. Means were computed for percent OMP and cross-sectional nasal airway. Results indicated that in general these children exhibited relatively high rates of OMP. Boys displayed significantly greater OMP than girls. However, children exhibiting OMP on 80% of the observation intervals had significantly smaller cross-sectional nasal areas than the youngsters who displayed OMP on fewer than 20% of observation intervals. The implications of the findings were discussed.