Sphenoid Sinus: Pneumatization and Septation Patterns in a Hispanic Population

Abstract

<b><i>Introduction:</i></b> Pneumatization of the sphenoid sinus (SS) varies widely among different ethnic groups. Information regarding the prevalence and significance of SS variants among Hispanic groups is limited. This study aims to describe and analyze pneumatization and septation patterns of the SS in a Hispanic population. <b><i>Methods:</i></b> A total of 160 paranasal sinus computed tomographies were reviewed by a head and neck-specialized radiologist and 2 otolaryngologists. <b><i>Results:</i></b> The postsellar and sellar types were the most frequent patterns of pneumatization observed, with a prevalence of 52.5 and 40%, respectively. Accessory septations were present in 59.4% of the patients. Septa were inserting over the internal carotid artery (ICA) in 43.8% and over the optic nerve in 17.5% of the population. No significant association (<i>p</i> > 0.05) was observed when comparing the different accessory septation patterns among the types of the SS. The frequency of septa inserting on the ICA was significantly higher in postsellar types (<i>p</i> < 0.001). Pneumatization of the anterior clinoid process, pterygoid processes, and greater wing was present in 20, 17.5, and 45.9% of the sinuses, respectively. Onodi cells were encountered in 40% of the sinuses. There were no significant differences in any of the pneumatization and septation variables when compared by gender and age (<i>p</i> > 0.05). <b><i>Discussion/Conclusion:</i></b> Differences regarding anatomical variants and septations of the SS were observed in our study when compared with findings reported in other ethnic groups. Preoperative assessment of the anatomical variants of the SS in Mexican patients is imperative to select the most optimal surgical approach and prevent iatrogenic injuries to related neurovascular structures.

Relationships of sphenoid sinus pneumatization with internal carotid artery characteristics

“…We thus examined the relationship between the ISS and ICA according to the extent of sphenoid sinus pneumatization (conchal, sellar, presellar, and postsellar types [ 22 ]). In previous studies, the postsellar type was predominant (46.7–86%) [ 1 , 23 , 24 ]; this was followed by the sellar type (29.4–98.8%) [ 5 , 9 , 21 , 25 – 28 ]. Our findings were similar: the postsellar type was present in 47.9% of patients, while the sellar type was present in 45.7% of patients.…”

“…The effect size of the ANOVA test to achieve 0.05 type 1 error and 80% power was calculated by G-Power (version 3.1.9.2; Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany) [ 18 ]. For the incidence of ISS insertion into paraclival ICA, at least 51 patients per each group were required with assuming 26.6~63.1% per each group and 43.8% of total incidence [ 1 ].…”

“…On the sagittal plane, if the posterior end of pneumatization extended to the front of the sellae, the pneumatization was considered presellar; if the end lay between the anterior and posterior ends of the sellae, the pneumatization was considered sellar; and if the end lay beyond the posterior ends of the sellae, the pneumatization was considered postsellar. Minimal pneumatization was considered conchal [ 1 , 4 , 5 ].…”

“…The pneumatization of the sphenoid sinus proceeds from about 3 years old to about 16 years old [ 1 ]. The sphenoid sinus is a structure that has many variations [ 2 ]; the degree of pneumatization differs from person to person, and according to the degree, it can be divided into conchal, presellar, sellar, and postsellar types [ 1 , 2 ]. In addition, the intersphenoid sinus septum (ISS) exists in various numbers and forms [ 3 – 5 ].…”

“…Several studies have identified the pneumatization of the sphenoid sinus and ISS and the relationship with the surrounding ICA and ON [ 1 , 5 , 10 , 16 , 17 ]. However, to the best of our knowledge, none has comprehensively summarized the positional relationship between the ICA and the ISS and the degree of aeration of the sphenoid sinus in a large population.…”