Left: Representative images of OMP immunostaining of the OE of the healthy, saline, and CGF groups on day 28 are shown. The square scale in the figure is 100 μm × 100 μm. The number of OMP-positive cells in this square scale was counted. Right: The number of OMP-positive cells of the CGF group is higher in the CGF group than in the saline group (P = 0.009). However, the value did not improve to the number of OMP-positive cells in the healthy group. CGF, concentrated growth factor; OE, olfactory epithelium; OMP, olfactory marker protein.