chapter  13
Paranasal sinuses
Pages 12

There are four paired paranasal sinuses, which are essentially extensions of the nose. These are the frontal sinus, the sphenoid sinus, the ethmoid air cells and the maxillary sinus.

Aims 179 Learning outcomes 179 Introduction 179 Sinusitis 180 Retained roots in the maxillary antrum 181 Oroantral communication 183 Other antral pathology 186 Elective operations affecting the maxillary sinus 187 Epistaxis 187

The frontal sinus is not present at birth, but it pneumatizes throughout the frontal bone in life and drains through the frontonasal duct.