Prevalence of Maxillary Sinus Hypoplasia and Silent Sinus Syndrome: A Radiological Cross-Sectional Retrospective Cohort Study

BACKGROUND

Maxillary sinus hypoplasia (MSH), associated with enophthalmos and hypoglobus in the silent sinus syndrome (SSS), is a poorly studied condition. The real incidence of MSH and SSS in the adult population is not known. Our study aims at estimating the radiological prevalence of MSH and identifying undiagnosed cases of SSS in a retrospective cohort.

METHODS

A cross-sectional retrospective cohort study was performed in adults, without a history of maxillofacial surgery or trauma, undergoing head CT scans. A radiological database of 1012 consecutive scans was reviewed independently by two authors to identify patients with signs of MSH and SSS and associated findings (septal deviation, uncinate deviation, concha bullosa, sinus opacification, bony rarefaction, and pterygopalatine fossa enlargement). The findings of MSH and SSS were compared with radiological reports.

RESULTS

891 eligible CT scans were analyzed. MSH and SSS prevalences were 6.17% (n = 55) and 0,56% (n = 5), respectively. The maxillary sinus was normally or partially ventilated in 96.36% of MSH patients. Lateralization of the uncinate process was detected in about 50% of MSH patients, while a septal deviation towards the affected sinus was detected in 21.82%. In 20% of MSH scans, a concha bullosa was identified. Radiological reports identified a single MSH case.

CONCLUSIONS

Our study confirmed the literature data on MSH prevalence, while it determined a precedently unknown prevalence for SSS, underestimated in the radiology reports. This prevalence needs further confirmation but suggests a routine accurate comparison of both maxillary sinuses in CT scans.

Natural progression of bilateral maxillary silent sinus syndrome: A metachronous case report

Silent sinus syndrome refers to a constellation of spontaneous and progressive enophthalmos and hypoglobus in the setting of asymptomatic ipsilateral maxillary sinus atelectasis. Although its exact etiopathogenesis is not completely understood, obstruction of the ostiomeatal complex appears to be the inciting event. Most of the reported cases of silent sinus syndrome involve one maxillary sinus. Only a handful of true bilateral silent sinus syndrome cases have been reported in the literature. The aim of this report is to present a case of metachronous bilateral maxillary silent sinus syndrome and its natural progression. Also included is a review of the literature on ethmoidal, frontal, and bilateral maxillary silent sinus syndrome.

Acquired Ophthalmoplegia in Older Children and Adults

Ophthalmoplegia or ophthalmoparesis are the terms given to paralysis or paresis of one or more of the extraocular muscles in one or both eyes. It may be representative of serious neurological or systemic disease. Other mechanisms may cause limitation of eye movement, including restrictive or myasthenic conditions, or combinations of several etiologies. Evaluating and differentiating the mechanisms causing ophthalmoplegia is important in determining the correct diagnosis and selecting the appropriate management in these complex cases.

Rapid remodeling of the maxillary sinus in silent sinus syndrome

Silent sinus syndrome (SSS) is a rare disorder involving bony remodeling of the maxillary sinuses, including collapse of the orbital floor. It is typically unilateral and seen in the setting of chronic maxillary sinusitis. Patients present with enophthalmos and hypoglobus occasionally accompanied by diplopia. The condition is generally diagnosed with CT imaging and treated surgically. While SSS is most often reported as very slowly progressive, we report a patient with evidence of significant remodeling of the maxillary sinus over a period of 5.5 months.

Hyaluronic Acid Gel Re-Injection for Enophthalmos Correction in Silent Sinus Syndrome

A 43-year-old female with residual enophthalmos following functional endoscopic surgery (FESS) due to silent sinus syndrome (SSS) was initially successfully treated with a 2-ml intraorbital injection of hyaluronic acid gel (HAG). The enophthalmos partially recurred 22 months after the injection. HAG was re-injected with good functional and cosmetic results. Functional (kinetic) computed tomography was performed to visualize HAG distribution in the orbit.

Mandibular symphysis graft versus iliac cortical graft in reconstructing floor in orbital blow out fracture: A comparative study

Aim:

The purpose of this study was to clinically and radiologically assess and compare the outcome of internal orbital reconstruction with an iliac bone graft and mandibular symphysis graft in orbital blow out fractures.

Materials and Methods:

Eight consecutive patients with unilateral orbital blow out fractures were enrolled in this prospective study. CT scan imaging and volumetric assessment of the orbit was done for all patients using GE Discovery VCT Workstation 4.4. Patients with defect of area less than 2 cm² and orbital volume expansion of less than 4.7 cm³ were treated with mandibular symphysis graft, in contrast the others were treated with a medial cortical graft from the anterior ilium. At each follow-up visit, globe posture, diplopia, and eye movements were assessed. Coronal and sagittal computed tomography and volumetric assessment were used to observe graft posture, bone defects and contour.

Results:

Group I cases showed that orbital volume changes of less than 2cm³ can be effectively reduced. Group II cases showed that orbital volume changes of more than 4.5 cm³ could not be effectively restored in spite of using large iliac graft. All eight patients had satisfactory correction of hypoglobus. Diplopia and ocular motility restriction resolved in all affected patients post operatively between 4^th day and 2^nd week. At 3-month follow-up, computed tomography demonstrated that the middle section of the orbital floor was well elevated in all 8 orbits. All grafts were still in situ, with density measured in Hounsfield units revealed that the Mandible Symphyseal graft was denser.

Conclusion:

The mandibular symphysis graft is a good, simple reconstructive option in small orbital floor defects with orbital volume change less than 4.71 ml. In larger defects with huge orbital volume changes that require more volume of graft, iliac graft is useful albeit, perfect, volumetric restoration is not always possible