Ostium resistance in acute maxillary and frontal sinusitis.

Ostium function tests were performed in 18 normal maxillary and 6 normal frontal sinuses. Further 57 patients with acute maxillary and 16 patients with acute frontal sinusitis were followed using sinumanometry until resolution of infection occured. After initial obstruction of the ostium, resistance decreased exponentially until complete decongestion. Respiratory pressure changes in the sinus during forced nasal breathing are a positive sign for healing of sinusitis. The amplitude of these fluctuations should be documented during each lavage and facilitates indication for drainage procedures.