When conservative therapies are not effective in treating sinus infections, alternate steps can be taken to improve paranasal cavity ventilation. These measures may include surgical procedures such as intranasal endoscopic or maxillary sinus fenestration, and other procedures such as placement of a maxillary sinus tube or a YAMIK sinus catheter. We conducted a prospective study of 25 patients to investigate the effects on the nasal mucosa of improved ventilation between the nasal and paranasal cavities. We accomplished this by comparing (1) the results of simultaneously measured nasal cavity and intramaxillary sinus pressures before and after widening of ventilation openings, (2) changes in mucociliary transport function as measured by the saccharin test, and (3) changes in nasal airway resistance. Just as multiple transit routes between the nasal cavity and maxillary sinus give rise to greater fluctuations in intramaxillary sinus pressure, and just as rapid breathing gives rise to even greater pressure fluctuations than does quiet breathing, we believe that both intranasal cavity airflow velocity and the number of ventilation openings present have an effect on the state of ventilation between the nasal cavity and maxillary sinus. We also suggest that the establishment of maxillary sinus ventilation openings improves mucociliary clearance.