Fig. 1

Grading of maxillary sinus mucosal thickening on MDCT images. a Grade 1, thickening of the maxillary sinus occupying the maxillary sinus volume is one third or less. b Grade 2, thickening occupying one third to two thirds of the maxillary sinus. c Grade 3, thickening occupying more than two thirds of the maxillary sinus