Nasal and paranasal sinus anatomy for the endoscopic sinus surgeon

Abstract

The nomenclature of the anatomy of the nasal cavity and of the paranasal sinuses is often used arbitrarily. Therefore only terms that have been precisely defined should be used in order to avoid further confusion. Endonasal sinus surgery requires exact and detailed anatomical knowledge, including that of the numerous morphological variations. This knowledge must be acquired by thorough cadaver dissections. The ethmoidal complex can be divided into the anterior and the posterior ethmoid. The separation line is the basal lamella of the middle turbinate. Cells located anterior to this lamella belong to the anterior ethmoid, while those located posterior to this lamella belong to the posterior ethmoid. The middle turbinate on the lateral nasal wall is a physiologically essential structure as well as an important landmark for orientation. Laterally beneath this structure, both the uncinate process and the ethmoidal bulla must be identified with precision. It is important that the dangerous ethmoidal formations classified as Keros types II and III be kept in mind to avoid perforation of the lateral wall of the olfactory groove. Accessory ethmoidal pneumatizations may occur: Onodi-Grünwald cells are crucial due to their physically close relationship with the optic canal and optic nerve. Frontal bullae are important for the morphology of the frontal infundibulum; the infraorbital cells (Haller cells) may include the infraorbital nerve. © 2009 Springer Berlin Heidelberg.