Device for oral administration of an aerosol for the rhinopharynx, the nasal cavities or the paranasal sinuses

Aerosol administration device comprising a generator of particles of size between 10 nm and 200 μm for forming an aerosol, a mouthpiece or oral mask for oral administration of the aerosol initially into a mouth of a patient during a nasal expiration phase or during a respiratory pause phase preceding nasal expiration, and a source of gas or pressure for conveying the particles, wherein the particle generator is operated manually or automatically, the mouthpiece and particle generator constitute an airtight assembly adapted to be connected to the mouth of the patient during aerosol administration phases, the mouthpiece penetrates beyond teeth of the patient by a maximum length of 4 cm and administers aerosol, starting in the mouth, for the nasal cavities, rhinopharynx or paranasal sinuses during the aerosol administration phases, such that the aerosol is successively conveyed from the mouthpiece to the mouth, then the rhinopharynx, then the nasal fossae and sinuses, and then said aerosol escapes through one or both nostrils of the patient, and the device does not allow expiration through the mouth of the patient during the aerosol administration phases.