Figure 3: Missed ostium sequence. a) Typical secretion drop directly behind obvious remnants of the uncinate process in MOS of the right side after previous surgery. b) In the coronal CT scan a larger opening of the maxillary sinus is seen in the posterior part of the middle meatus (*). c) In the area of the natural ostium, however, remnants of the uncinate process and soft tissue are revealed (mucosal swelling, scars (=1) with obstruction of the natural ostium in contrast to free drainage on the left side (=2)).