"Silent Sinus Syndrome" Following Orbital Trauma: A Case Series and Review of the Literature.

Purpose: To describe the demographics, presentation, and treatment of "silent sinus syndrome" (SSS) diagnosed following orbital trauma and review the literature on this topic.

Methods: A retrospective review of 6 consecutive cases of SSS following trauma seen by the authors from 2004 to 2015. Data collected included patient demographics, details of previous trauma, clinical presentation, imaging findings, surgery performed, outcome, and follow up.

Results: Six patients were identified presenting with SSS following orbital floor fracture. All cases developed progressive enophthalmos due to maxillary sinus atelectasis on average 8 months after their initial trauma (range, 3-16 months). The appearance of the maxillary sinus on CT was indistinguishable from the changes seen in spontaneous SSS. All 6 patients had surgical repair, which included maxillary sinus reventilation and surgery to build up the orbital floor and correct the enophthalmos in 4 patients, maxillary sinus reventilation surgery only in 1 patient and surgery to build up the orbital floor only in 1 patient. There was a reduction of enophthalmos and globe dystopia in all cases with no significant complications.

Conclusions: Changes in the maxillary sinus after orbital floor fracture may occur in the months following the initial trauma and the changes are indistinguishable from those seen in spontaneous SSS. The mechanism is presumed to be obstruction of the natural ostium of the maxillary sinus, accumulation of secretions and the development of negative pressure within the sinus leading to its collapse.