Functional endoscopic sinus surgery: Before and after

The illustration demonstrates an example of the paranasal sinuses before (left) and after (right) functional endoscopic sinus surgery (FESS). The uncinate process has been removed and the maxillary os widened. The septae between the ethmoid cells have been removed, and the opening to the frontal sinus has been widened. The more posteriorly positioned sphenoid sinus is not shown. Surgery commonly includes both sides, but, in this illustration, the two sides are shown as before and after for instructional purposes only. Note that before surgery (left), the mucosal lining is thickened and swollen from longstanding inflammation. The mucosal lining is not disturbed by the surgery, but, over time and with better aeration and greater exposure to topical medications, the lining should return to a normal thickness (right), and mucous production should decrease.