A Computerized Tomographic Study of Morphology and Pneumatization of Crista Galli

Abstract

Introduction:Asymmetrically divided sphenoid sinuses exhibits a variety of variation in the presentation of inter sinus septum. Previous reported range of incidence of single midline inter-sphenoid sinus septum is from 18.2% to 95%. Many studies have reported differing incidences of laterally placed septum, accessory septa, multiple septa, transverse septa and no septum in the sphenoid sinuses. Termination of inter-sphenoid septum either into internal carotid canal or into optic canal had also been shown in many studies with possibilities of high risk complications related to such termination of septum. As there exists only limited data in Indian ethnicity about the variations in presentation of inter-sphenoid sinus septum compounded by the relative high frequency of occurrence of endoscopic trans sphenoid microsurgeries, this study was done to observe variations occurring in septum of sphenoid sinuses. Materials and Methods:A retrospective CT analysis of images obtained from 114 patients diagnosed with sinusitis during a specific study period was done by two independent observers. The age of the patients ranged from 16 -60 years of both sexes. Patients with history of prior sinus or sphenoid surgery, facial trauma, obscured sphenoid sinus pathology were excluded. Results:Single inter sphenoid sinus septum was seen in 83.3% .Out of this Midline, right deviation, left deviation were observed in 11.4%, 33.9% and 21.9% respectively. In 16.7 % images accessory/ multiple septum were noticed. While, absent inter sphenoid septum and transverse septum were noted each in 0.8% of images studied. The termination of inter sinus septum to internal carotid canal occurred in 27.3% and into optic canal in 48% of all images studied. Conclusion:This study concluded that the variation in the presentation of inter-sphenoid septum and its termination at internal carotid artery canal or optic canal need to be pre operatively evaluated by surgeons for considering risk of septal resection during Trans-sphenoid endoscopic surgeries.

Pneumatized Crista Galli: A Histopathologic Study

“…Last, the demographics of the patients used in the studies varied, as some researchers created groups based on their age while others did not. As some of the studies showed, PCG is often connected to the frontal sinus 3–8 . Since the development of frontal sinuses lasts until puberty, 20 age is an important factor in PCG incidence.…”

“…A number of studies have been reported on the incidence of PCG, with stunningly different results ranging from 2.4% to 86%. [2][3][4][5][6][7][8][12][13][14][15][16][17][18][19] All of them, except that by Mladina et al, 16 were radiologic studies that investigated CT scans of symptomatic patients. To our best knowledge, this is the first histopathologic study of the incidence of PCG.…”

“…Due to the embryologic origin of crista galli from the ethmoid bone, it would seem that its pneumatization would come from the ethmoid air cells. However, a number of studies have linked PCG with the frontal sinus 3–8 …”

“…However, a number of studies have linked PCG with the frontal sinus. [3][4][5][6][7][8] Due to its pneumatization and connection with the nearby air cells, PCG can have a lining of normal upper respiratory system mucosa. This mucosal lining may be the origin of pathologies associated with the nasal region and paranasal sinuses, such as CRS 6 and mucocele formation.…”

The Incidence of Sinus Crista Galli in Children and Adults. A Computerized Tomography Study

“…The pneumatization area in the crista galli region of the ethmoid bone is called sinus crista galli (SCG), which is a part of the ethmoid bone embryologically. However, studies have reported that crista galli pneumatization is associated with the frontal sinus (Som et al, 2009;Kamala et al, 2016;Mladina et al, 2017).…”