Silent sinus syndrome is a spontaneous, asymptomatic collapse of an air sinus (usually the

maxillary sinus The pyramid-shaped maxillary sinus (or antrum of Highmore) is the largest of the paranasal sinuses, and drains into the middle meatus of the nose through the osteomeatal complex.Human Anatomy, Jacobs, Elsevier, 2008, page 209-210 Structure It is ...

and orbital floor) associated with negative sinus pressures. It can cause painless facial asymmetry,

diplopia Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often v ...

and

enophthalmos Enophthalmos is a posterior displacement of the eyeball within the orbit. It is due to either enlargement of the bony orbit and/or reduction of the orbital content, this in relation to each other. It should not be confused with its opposite, ex ...

. Diagnosis is suspected based on symptoms, and can be confirmed using a CT scan. Treatment is

surgical Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...

involving making an outlet for mucous drainage from the obstructed sinus, and, in some cases, paired with reconstruction of the orbital floor. It is slightly more common in

middle age In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

Signs and symptoms

Silent sinus syndrome can cause facial asymmetry (usually without pain), and vision problems (such as

and

). It may also cause

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

s, and a feeling of fullness in the

nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes th ...

Mechanism

Silent sinus syndrome most often affects the

, usually with a collapse of the orbital floor. It may also affect the

frontal sinus The frontal sinuses are one of the four pairs of paranasal sinuses that are situated behind the brow ridges. Sinuses are mucosa-lined airspaces within the bones of the face and skull. Each opens into the anterior part of the corresponding middle na ...

or the

ethmoid sinus The ethmoid sinuses or ethmoid air cells of the ethmoid bone are one of the four paired paranasal sinuses. The cells are variable in both size and number in the lateral mass of each of the ethmoid bones and cannot be palpated during an extraoral e ...

. When the maxillary sinus is involved, the

inferior oblique muscle The inferior oblique muscle or obliquus oculi inferior is a thin, narrow muscle placed near the anterior margin of the floor of the orbit. The inferior oblique is one of the extraocular muscles, and is attached to the maxillary bone (origin) and ...

may be damaged. The cause of silent sinus syndrome is not well understood. Bacteria in the

may be involved. The connection to the

may be blocked. This can create

negative pressure Negative pressure may refer to: * Negative value of a pressure variable * Negative room pressure, a ventilation technique used to avoid contaminating outside areas * Negative pressure ventilator, also known as an iron lung * Negative-pressure wou ...

in the sinus, as secretions are reabsorbed.

Diagnosis

Silent sinus syndrome is first suspected based on symptoms. A CT scan can be used to confirm a diagnosis. This can have characteristic features, including maxillary sinus outlet obstruction, sinus opacification, and sinus volume loss caused by inward retraction of the sinus walls.

Differential diagnosis

Silent sinus syndrome is a subtype of stage three chronic maxillary atelectasis. The distinguishing factor is that in silent sinus syndrome, there is an absence of sinusitis symptoms. To be clear, chronic maxillary sinusitis may be a primary causitive factor in a significant number of silent sinus syndrome cases, it just may be asymptomatic. Silent sinus syndrome also must be distinguished from maxillary sinus

hypoplasia Hypoplasia (from Ancient Greek ὑπo- ''hypo-'' 'under' + πλάσις ''plasis'' 'formation'; adjective form ''hypoplastic'') is underdevelopment or incomplete development of a tissue or organ.

Treatment

Silent sinus syndrome is usually treated with surgery. The first stage involves restoring sinus function, most often by performing an

endoscopic An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

uncinectomy (removal of uncinate process) and maxillary antrostomy. The second stage, if needed, involves reconstruction of the orbital floor. While some clinics perform the two stages simultaneously, most authorities recommend waiting a minimum of 6 or as many as 18 months, as spontaneous remodeling of the orbital floor after the sinus repair will occur in many if not most cases. Any prolapsed contents (such as those from the

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a p ...

) must be put back in place, though this is an rare occurrence in an already rare syndrome. If the

is damaged, it may be partially removed (known as myectomy). Mucus and secretions must be drained from the sinus. Earlier treatment has better outcomes.

Epidemiology

Silent sinus syndrome is fairly rare. It can occur at any age, but is slightly more common in

middle-aged In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the Post-classical, post-classical period of World history (field), global history. It began with t ...

people. It occurs equally in sinuses on each side of the face.

History

Silent sinus syndrome was first described in 1964.

References

Bibliography

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External links

{{Medical resources , ICD10 = , ICD9 = , ICDO = , OMIM = , DiseasesDB = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , MeSH = , GeneReviewsNBK = , GeneReviewsName = , Orphanet = 71276 Human head and neck