Silent sinus syndrome

Silent sinus syndrome is a spontaneous, asymptomatic collapse of the maxillary sinus and orbital floor associated with negative sinus pressures. It can cause painless facial asymmetry , diplopia and enophthalmos. Usually the diagnosis is suspected clinically, and it can be confirmed radiologically by characteristic imaging features that include maxillary sinus outlet obstruction, sinus opacification, and sinus volume loss caused by inward retraction of the sinus walls. Treatment is surgical involving making an outlet for mucous drainage from the obstructed sinus.

Unenhanced CT image in coronal plane reveals fully developed opacified right maxillary sinus. Uncinate process is apposed to inferomedial orbital floor, occluding maxillary sinus infundibulum (arrow). Associated lateral retraction of medial sinus wall and middle turbinate with enlargement of middle meatus (asterisk) can be seen. Orbital floor is retracted into sinus lumen (arrowhead).