Abstract
A method for measuring the resistance of the maxillary ostium in cases with a relatively pronounced ostial obstruction is described. Antral lavage is performed by raising a bottle with irrigation fluid at a slow constant rate, by means of an elevator. The height between the fluid level and a point one cm below the infra-orbital margin is measured when the fluid starts to drop from the nose. The results of 100 irrigations in 57 patients show that the ostial resistance is more pronounced in chronic than in acute sinusitis. The ostial resistance decreases in acute sinusitis when the inflammation subsides, while it usually remains high in chronic sinusitis even when there is no mucus or pus in the antral lavage.