The Silent Sinus Syndrome (SSS) is a rare condition that causes facial asymmetry, unilateral enophthalmos and diplopia. It is thought to be secondary to chronic maxillary sinus atelectasis (CMA) with reabsorbed bone and subsequent displacement of the orbital floor. Such anatomic modifications occur over time, and therefore it is possible to encounter different stages of the same disease with or without orbital displacement. Clinical findings can be unclear so it makes sense to recognize potentially evolving SSS while other disturbances have to be ruled out. Our purpose is to underline clinical findings for different diagnosis and proper management. We consider Functional Endoscopic Sinus Surgery (FESS) indicated in CMA and SSS to halt the progression of the disease. Nevertheless restitution treatment of enophtalmos due to orbital floor displacement involves plastic reconstruction of the floor of the orbit via transconjunctival approach. We report a case of SSS and discuss distinctive features of non-neoplastic lesions involving the maxillary sinus that should be considered for differential diagnosis.