Hypertrophied mucosa of the maxillary sinus is a diagnostic criterion, including odontogenic maxillary sinusitis. Until now, mucosal hypertrophy as an evolutionarily conditioned compensatory mechanism necessary for maintaining homeostasis of the maxillary sinus has not been considered. Objective of the study. To determine the radiographic density of hypertrophied mucosa of the maxillary sinus forming the walls of the bypass canals. Materials and methods. To achieve the objective of the study, the radiographic density of hypertrophied mucosa was assessed in 50 somatically healthy individuals with an average age of 37.6 ± 3.8 years. Results. It was found that the radiographic density of hypertrophied mucosa in the area of the bases of the bypass canals was –97.06 ± 7.53 HU, in the area of the mouth –307.43 ± 12.66 HU. Significant differences in this parameter indicate varying hydrodynamic significance of the topographic sections of the hypertrophied mucosa subject to occlusal load. The radiographic density of extravasal fluid at the base of the bypass channels is –218.22 ± 10.27 HU, while at the mouth, the density decreased to –538.57±24.49. These findings characterize complex hydrodynamic and biological processes caused by occlusal loading of the teeth, occurring within the hypertrophied mucosa, a recognized differential diagnosis of odontogenic maxillary sinusitis.