"Silent sinus syndrome represents maxillary sinus atelectasis, resulting in painless enophthalmos, hypoglobus and facial asymmetry 1,3. Some authors restrict the term to patients with no history of sinusitis, trauma or surgery 2. Some authors suggest it is part of the spectrum of chronic maxillary atelectasis 6."
"Silent sinus syndrome represents maxillary sinus atelectasis, resulting in painless enophthalmos, hypoglobus and facial asymmetry 1,3. Some authors restrict the term to patients with no history of sinusitis, trauma or surgery 2. Some authors suggest it is part of the spectrum of chronic maxillary atelectasis 6."
"Chronic occlusion of the maxillary sinus ostium/ostia results in gradual resorption of the air. Subsequently, negative pressure is generated within the sinus 3. This, in turn, results in gradual inward bowing of all four of the maxillary walls: roof (orbital floor), medial, posterolateral and anterior walls. Orbital volume increases with resultant enophthalmos and variable flattening of the malar eminence 1."
"Once drainage is established, no further volume loss will develop and, in some patients, enophthalmos and hypoglobus may even partially resolve 8. This can be achieved with functional endoscopic sinus surgery (FESS) or historically with a medial maxillary antrostomy or even Caldwell-Luc procedure 7-9."
"A number of other hypotheses have been advanced, including inflammatory erosion and softening of walls due to chronic sinusitis; or sinusitis in a hypoplastic sinus 4. However, manometric measurement in a number of cases has confirmed the presence of negative pressures, as well as proof of normal-sized sinuses on previous imaging 3 - these make the latter two hypotheses unlikely."