In spite of widespread use of aerosols in respiratory diseases, very few studies have been performed in the field of nose and paranasal sinuses disorders. The nose is the front line defender of the respiratory system. The major functional roles of nasal breathing are defense against infiltrating particles and conditioning the inspired air to nearly alveolar conditions (body temperature and fully saturated with water vapour) in order to maintain the internal milieu of the lung. The site of particle deposition depends on particle parameters such as size, shape, and solubility, breathing parameters (flow rate and tidal volume), and the time at which the particle is inhaled during the breathing cycle.

Recent studies suggest that topical therapy is beneficial in many conditions underlying chronic rhinitis. Results of some studies confirmed, that aerosols could reach the middle meatus of the nose, which is the main area for sinusitis disorders. Current literature has documented low particle deposition efficiency into the paranasal sinuses. Three factors influence the deposition efficiency: particle size, pressure gradient, and the size of the sinus ostium. Ostium size is the most dominant factor. Therefore, since the therapeutic particles might not enter the maxillary sinus when the diameter of the sinus ostium is less than 1mm, some pretreatment to open the sinus ostium canal would be necessary before applying such aerosol in practice. The topical administration of drugs to the paranasal sinuses postoperatively must be performed in consideration with aerodynamics of aerosols.