Silent sinus syndrome (SSS), also known as Maxillary atelectasis with enophthalmos and imploding antrum, is the painless (silent) involution of the maxillary sinus with associated enophthalmos due to gradual collapse of the orbital floor.
It is thought that SSS is caused by hypoventilation of the maxillary sinus due to obstruction of the ostiomeatal complex. The trapped gas is resorbed into capillaries, creating negative pressure. There is also accumulation of secretions and chronic inflammation, resulting in maxillary atelectasis and wall collapse.
Patients present with enophthalmos (2-5 mm). Diplopia and other ocular symptoms are uncommon, likely due to the gradual course of the disease.
CT findings include:
- Complete or near-complete unilateral obstruction of the maxillary sinus
- Obstruction of the ostiomeatal unit
- Lateral retraction of the uncinate process, resulting in relative enlargement of the middle meatus
- Nasal septal deviation
- A variable degree of retraction and collapse of all the walls of the maxillary sinus, manifested as concavity, resulting in inferior displacement of the globe and orbital contents into the maxillary sinus
- Demineralization of sinus walls
- Increased retroantral fat pad on the affected side
References
- Annino DJ Jr, Goguen LA. Silent sinus syndrome. Curr Opin Otolaryngol Head Neck Surg. 2008 Feb;16(1):22-5.
- Waqar S, Dhir L, Irvine F. Silent sinus syndrome: a cause of unexplained enophthalmos. Can J Ophthalmol. 2010 Oct 24;45(5):547-548.
I had this. First it was diagnosed as a blocked tear duct. Then it was thought to be a different kind of eye infection. Then it was thought to be a brain tumor. After the MRI showing no tumor but a bad sinus infection, it was suggested by the ENT that it was a childhood injury to the eye socket, and the eye issue had nothing to do with the sinus issue. Finally, a family member armed with Google diagnosed SSS.
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