Endoscopy of the maxillary sinus.
D002908:Chronic Disease; D004724:Endoscopy; D006801:Humans; D008443:Maxillary Sinus / Q000000981:diagnostic imaging; D055095:Optics and Photonics / Q000295:instrumentation; D010781:Photography; D011859:Radiography; D012852:Sinusitis / Q000175:diagnosis* / Q000000981:diagnostic imaging