Applied surgical anatomy of the nasal cavity and paranasal sinuses

The paranasal sinuses comprise the frontal, maxillary, ethmoid and the sphenoid sinuses. The sinus drainage pathways divide the paranasal sinuses into anterior and

posterior systems that are anatomically separated by the basal lamella of the middle turbinate (see page 2). The anterior drainage system drains the frontal, maxillary and anterior ethmoids, and the posterior system drains the posterior ethmoids and the sphenoid. Pathology may involve one or more of these drainage systems.