The cheek (maxillary) sinus has to pump mucus uphill to reach its drainage hole, which sits at the top. The inside of the sinus is very large compared to the size of its drain. Once the fluid leaves through the sinus opening, it crosses the uncinate bone and then flows over the top of the lower turbinate.

Introduction 1
The Lab
Sinuses Side
Sinuses Front
Mid-Sagittal
Septum
Deviated Septum
Deviated Septum
Inferior Turbinate
Inferior Turbinate
Middle Turbinate
Concha Bullosa
Middle Turbinate
Middle Turbinate
Airflow
Airflow
Frontal
Frontal
Drainage
Drainage
Drainage
Drainage
Sphenoid
Sphenoid
Maxillary
Maxillary
Maxillary
Mucous Flow
Ostio-Meatal
Ostio-Meatal
Polyps
Polyps
Windows
Windows
Endoscopic
Endoscopic
Turbinate Reduction
Turbinate Reduction
Cool Picture