“M” line: New anatomical landmark for the maxillary sinus natural ostium

Objective Describe a reliable anatomical landmark that can be used to locate the maxillary sinus natural ostium (MSNO) during endoscopic surgery, even if the uncinate process is preserved. Design Descriptive anatomical. Setting An anatomical and radiological study was performed to evaluate the consistency of the landmark, denominated "M" line. Subjects and Methods Dissections were performed in 57 cadaver heads (114 sides). In addition, 73...