Ethmoid Bone, Inferior View

Description

Presented from an inferior aspect, the ethmoid bone is oriented with the perpendicular plate descending in the midline to form the superior nasal septum, while the paired ethmoidal labyrinths sit lateral to it and create much of the medial orbital wall and superior nasal cavity. Curving along the inferomedial margin of each labyrinth, the uncinate process projects posteroinferiorly as a thin lamina that helps define the ethmoidal infundibulum and the semilunar hiatus. Multiple ethmoidal air cells are visible as clustered cavities within the labyrinth, separated by delicate bony septa. Paper-thin anatomy. For endoscopic sinus surgery, this inferior viewpoint clarifies relationships that drive safe access to the anterior ethmoid and maxillary sinus drainage pathway: the uncinate process, infundibulum, and adjacent ethmoidal cells. Surgeons target the uncinate in uncinectomy and functional endoscopic sinus surgery to address chronic rhinosinusitis and obstructed ostiomeatal complex, but orientation errors can place the orbit at risk because the lamina papyracea lies immediately lateral to the ethmoid labyrinth. Teaching these spatial cues early reduces confusion between septal structures (perpendicular plate) and lateral wall anatomy (uncinate and ethmoidal cells). Ideal for gross anatomy and head and neck modules, ENT teaching files, and surgical atlases illustrating the ostiomeatal unit and ethmoidectomy landmarks, as well as patient-facing education on sinus drainage and recurrent ethmoid sinusitis. Radiology educators can pair it with coronal CT anatomy to map ethmoid air cells and the uncinate process to operative corridors. Anatomical accuracy verified by SciePro's Medical Advisory Board.