Silent sinus syndrome: CT and MRI findings

Delayed onset enophthalmos and hypoglobus mimicking silent sinus syndrome following midface trauma

Craniomaxillofacial trauma is primarily diagnosed and managed by oral and maxillofacial surgeons. Among the cases encountered, midface fractures involving orbital walls are highly prevalent. In these fractures, involvement of the orbital walls, particularly floor of the orbit, can lead to considerable aesthetic and functional limitations. From a maxillofacial perspective, indications for surgical repair of orbital floor encompass marked decrease in ocular motility, fracture affecting more than 50% of surface area, an increase in orbital volume exceeding 18% and enophthalmos greater than 2 mm. In the absence of these discernible signs, surgical intervention is not generally indicated. However, in this case, an early adolescent with a history of midface trauma and minimal orbital floor fracture 8 months earlier presented with progressively delayed onset enophthalmos and hypoglobus closely resembling features of silent sinus syndrome. The enophthalmos and hypoglobus were corrected by placing custom-made non-resorbable high-density polyethylene implant in the orbital floor. Postoperative follow-up demonstrated aesthetically and functionally satisfactory outcomes.

Etiology, Early Diagnosis and Proper Treatment of Silent Sinus Syndrome Based on Review of the Literature and Own Experience

PURPOSE

The authors' aim was to review the literature in terms of the etiology of the syndrome, the frequency of Silent Sinus Syndrome (SSS) and surgical procedure, as well as to present their own experience.

METHODS

The authors used PubMed, Medline, and Science Direct websites to find and review the most significant papers related to SSS. The case reports of SSS published between 2010 and 2020 were reviewed. A retrospective case review of 8 patients with SSS treated at the authors' departments was done.

RESULTS

The silent sinus syndrome has been reported in both children and adults. It is relatively rare and should be differentiated from congenital sinus hypoplasia or atelectasis. It most often affects the maxillary sinus. SSS is usually diagnosed when facial asymmetry or vision problems occur. Late diagnosis requires endoscopic sinus surgery, involving orbital wall reconstruction. The etiology of the syndrome, including the role of bacterial flora found in the sinuses, is unclear.

CONCLUSION

Early diagnosis of SSS enables avoiding orbital complications and limits surgical intervention to endoscopic surgery. Further research into bacteriology may help to understand the pathophysiology of the silent sinus syndrome.

Silent Sinus Syndrome: Interesting Computed Tomography and Magnetic Resonance Imaging Findings

Silent sinus syndrome (SSS) is the spontaneous unilateral collapse of the maxillary sinus and orbital floor with complete or partial opacification of the collapsed sinus. The key features in a patient who presents with SSS are painless progressive unilateral maxillary sinus disease in the absence of rhinosinusitis, trauma, or surgery. SSS is a rare disorder but could be under-diagnosed because of a lack of recognition. SSS is characterized by spontaneous and progressive enophthalmos (“sunken” eye-eye recession into the globe) and hypoglobus (globe displaced downward; and a drop in the pupillary level), so it is common for these patients to present first to an ophthalmologist. Although mostly observed in adults, there have been reports of SSS in children. SSS in younger individuals has characteristic clinical and radiologic signs with, in many cases, abnormal intranasal anatomic characteristics on the affected side. SSS should be differentiated from other causes of spontaneous enophthalmos, such as Parry-Romberg syndrome and linear scleroderma. The aim of this report was to alert the reader to the imaging findings in patients with SSS. This syndrome is well recognized by rhinologists and to a lesser extent to ophthalmologists but remains relatively unknown to general radiologists.

Laughter-Induced Transient Vision Loss in a Patient With Silent Sinus Syndrome

BACKGROUND

To report a patient with silent sinus syndrome (SSS) who experienced transient ipsilateral monocular vision loss during intense laughter.

METHODS

Case report.

RESULTS

Our patient's transient vision loss completely resolved after maxillary sinus decompression and during 7 months of follow-up.

CONCLUSIONS

Although the precise mechanism of our patient's vision loss remains undetermined, we suspect that the vascular supply to the eye and/or the optic nerve was compromised as the result of the combination of laughter (causing Valsalva maneuver and increased intrathoracic pressure) and SSS.

[Imploding antrum syndrome: three cases with different management approaches]

BACKGROUND

Silent sinus or imploding antrum syndrome is a very rare condition, consisting of a usually asymptomatic spontaneous collapse of the sinus walls and floor of the orbit. It is associated with negative pressures, and when this occurs, it presents with manifestations such as enophthalmos, hypoglobus, and tilt flow orbital floor. As its incidence is very low, it is frequently missed as a diagnosis, and in fact there are currently fewer than 150 cases reported in the literature.

CLINICAL CASES

Three patients have been identified in our practice over a period of two years, with different symptoms that influenced the decision of the treatment modality, which were: watch and wait, endoscopic sinus surgery, or endoscopic sinus surgery plus orbitoplasty.

CONCLUSIONS

Despite being a rare entity, it stills catches the attention of the ENT, OMF surgery and Ophthalmologist. The diagnosis is mainly radiological, due to the late clinical manifestations and symptomatology. The treatment should be individualised and based on the symptoms and the individual decision of each patient, firstly by Functional Endoscopic sinus surgery, and once sinus permeability is restored, it may require augmentation surgery of the orbital floor, either with autologous bone implant, titanium or other material. It is important to be aware of this pathology, to know and to suspect it, avoiding misdiagnosis.