The surgical anatomy of the middle nasal meatus.

An exact study was made of the middle nasal meatus in 20 anatomical preparations (left and right) from 10 subjects. Some features (the ethmoidal bulla, the uncinate process of the ethmoidal bone, the openings of the maxillary and frontal sinuses) are relatively constant in their arrangement, but very variable in shape and size. An understanding of these structures is now essential for the practice of endonasal microsurgery.