Bilateral Silent Sinus (Imploding Antrum) Syndrome.

Silent sinus syndrome, also termed imploding antrum syndrome, describes spontaneous enophthalmos arising from contracture of the maxillary sinus in the complete absence of any symptomatic sinonasal disease. The unusual nasal structure that probably causes the condition renders its occurrence almost exclusively unilateral. The authors describe a patient with left silent sinus syndrome, who presented 4 years later with right silent sinus syndrome; to the authors' knowledge, this is only the second case of bilateral sequential silent sinus syndrome. Each side was successfully managed with endoscopic antrostomy and secondary orbital floor repair.