Introduction: Silent Sinus Syndrome (SSS) is a rare pathology, characterized by retraction of the maxillary sinus walls, leading to enophthalmos, sometimes diplopia and midfacial depression. It is usually not associated with sinonasal symptoms. Sinus ventilation and drainage stops its progression, but usually cannot reverse the process. This empiric treatment supports the Hypoventilation Theory that would explain the pathogenesis of this disorder.
Materials & methods: We describe two cases of SSS. A 65 year-old-man complaining of enophthalmos with an insidious onset whose CT-Scan confirmed SSS. After he was submitted to drainage surgery, the ocular asymmetry showed slight improvement. The second case describes a 34 year-old-woman with a sudden onset enophthalmos associated with diplopia, in only 5 days. She didn't have nasal or sinus related symptoms. CT-scan revealed SSS due to maxillary and ethmoidal sinus. Early endoscopic surgery enabled reversal of enophthalmos and correction of diplopia.