Towards a better diagnosis of mouth breathing: validity and reliability of a protocol for assessing the awake breathing pattern in preschool children.

The children were preschoolers without craniofacial anomalies, pulmonary, neurological or cardiac pathologies, or genetic syndromes, so the results may not apply to children with those conditions. The mouth CO2 sensor used adult cannulas that were large for young children, and some children touched the sensor or spoke, although the researchers reminded them. The ABPA tablet was inclined at 45 degrees, which may have changed head posture and mouth posture. The coloring activity involved motor movement, which sometimes changed mouth posture. The cutoff used to turn the continuous CO2 percentage into two categories may have affected sensitivity. The study adapted a three-category grid into two categories, so it does not settle whether oronasal breathing is a separate pattern. The paper says further studies are needed in other ages or with associated medical conditions.

The study was funded by Fond de la Recherche Scientifique F.R.S-FNRS, grant FRESH 40004234. The CO2 analysis software was created by PLHealthcare in collaboration with the University of Liège.

Do not use the ABPA as a stand-alone screening test for mouth breathing. It had good specificity but lower sensitivity compared with the CO2 reference, so it is better for confirming a suspected pattern than for finding every child who mouth breathes.