The treatment of the patients presenting with pathologies of the maxillary sinus (MS) constitutes major activity in the otorhinolaryngological practice. The present article was designed to report the results of the computer-assisted modelling of the air flows formed in the nasal cavity during breathing under the normal conditions. In addition, the newly developed computer-generated models of the principal surgical interventions on the maxillary sinus are proposed including those of supraturbinal approach (medialization of the middle turbinated bone by 2 mm, the removal of the processus uncinatus, the broadening of the natural MS fistula (up to 1 cm in diameter), infraturbinal surgical approach (anastomosis between MS and the nasal cavity 0.5 cm in diameter under the inferior turbinated bone), balloon sinusoplasty (BS) of the maxillary sinus (broadening of the natural anastomosis up to 5 mm and of the hiatus semilunaris up to 7 mm). Also, mobilization of the processus uncinatus (MPI) is described including medialization of the middle turbinated bone by 2 mm and of the processus uncinatus by 1.5 mm is described. The results of the study give evidence of the absence of mass exchange between the nasal cavity and the normal maxillary sinus. It was shown that the air flow rate in the middle nasal passage amounted to 0.08±0.02m/sec after the modelling of the supraturbinal surgical approach; certain models allowed to increase the peak air flow rate in this region almost up to 10 m/sec. The mass exchange between the maxillary sinus and the nasal cavity equaling zero under the normal conditions increased up to 36.7 ml/sec whereas modelling of balloon sinusoplasty resulted in the development of mass exchange between the above structures equaling only 7.8 ml/sec. The infraturbinal surgical approach was associated with the mass exchange over 60 ml/sec due to the presence of two anastomosdes and the formation of the phenomenon of «aerification» of the maxillary sinus. Computational aerodynamics of the maxillary sinus and the nasal cavity has demonstrated both the absence of the changes in the air flow rate and the absence of the mass exchange between the above cavities following MPI by the newly proposed method.