Silent sinus syndrome (SSS) is a rare and interesting clinical condition that is associated with spontaneous, painless, unilateral enophthalmos and hypoglobus resulting from downward bowing of the orbital floor, in the absence of any symptomatic sinonasal disease.

It generally affects younger patients between the third and fifth decades of life.

The pathogenesis of silent sinus syndrome is based on chronic maxillary sinus obstruction, related to occlusion of the maxillary infundibulum which results in a hypoventilated sinus and negative pressures. Endoscopic sinus surgery to create a wide maxillary antrostomy with or without orbital floor reconstruction is considered the gold standard treatment of choice.