[Clinical anatomy of the paranasal sinuses. Descriptive anatomy, topography and important variations].

Detailed knowledge of the complicated anatomy and topography of the paranasal sinuses is an essential requirement for successful surgery in this region. The topographical relationship to essential neighbouring structures (vessels, nerves and spaces) must be borne in mind. Typical landmarks play a particularly important role, especially for reliable orientation in endoscopic procedures. Therefore, it must be stressed that detailed anatomical knowledge of the complicated nasal and paranasal architecture is very important for the success of nasal and paranasal surgery, as well as for the avoidance of serious complications. However, this knowledge can only be acquired by performing numerous dissections of the nasal and paranasal system once a good theoretical grasp of the various structures, regions and their nomenclature has been gained. Common anatomical variations, which may lead to complicated and hazardous changes in normal anatomy, are also of particular importance and the surgeon must be familiar with these variations.