[Anatomical limits of endonasal ethmoidectomy].

Constant anatomic boundaries of the lateral mass of the ethnoid are described, based on data from microdissections, endoscopic examinations, computed tomography imaging and histology in 12 subjects. As with surgical progression, identification of these boundaries follows the lateral orbital and superior craniofrontal surfaces. The "starred groove formation", ethmoidal roof lamina and ethmoidosphenoidal recesses are the safety beacons for endonasal ethmoidectomy under endoscopic control.