The severity of maxillary sinus was considered as 1 if there was an incomplete involvement. If there was an S shape deviation in septum, the more deviated angle was considered for analysis. In this picture, the septum is deviate first to left (green color) and then to right (red color), but because the deviation to right was much more than the other side, the first deviation to left was ignored.
Mohebbi et al. BMC Ear, Nose and Throat Disorders 2012 12:15 doi:10.1186/1472-6815-12-15