Variations of sphenoid pneumatization: a CBCT study

Abstract

The transsphenoidal approach of the skull base has become a usual surgical procedure which targets the sellar, parasellar and suprasellar regions of the middle cranial fossa, as well as Meckel's cave and the clivus 1 . Anatomical studies are essential in increasing the anatomical knowledge and improving surgical performance 2 . Although pituitary surgery is traditionally within the realm of neurosurgeons, otolaryngologists became active partners in the surgical management of hypophysis to decrease rates of complications and morbidity 3 , being known that the posterior ethmoid air cells and the sphenoid sinus are surrounded by more vital structures than any other sinus 4 .The sphenoid sinus is probably the most variably pneumatized structure of the skull; its recesses are able to facilitate minimally invasive access to different surgical targets, thus it play roles in the selection of surgical procedures 1 . From a developmental point of view, the sphenoid sinus will not reach its full extension until adolescence and it may occasionally extend into the vomer, ethmoid, palatine and occipital bones, as well as in different parts of the sphenoid bone, such as the anterior clinoid process, the lesser wing and the great wing, and the pterygoid process 5 . The pneumatizations of the anterior clinoid process and pterygoid process are surprisingly common 6 .According to its sagittal extension, as related to the sella turcica, the sphenoid sinus was classified either in three, or in four types. There are authors describing sellar, presellar and conchal types of sinus, which occur in 55%, 17% and, respectively, 28% of cases 7 . This classification in three types was suggested by Congdon in 1920 8 . Other authors also considered the postsellar pneumatization 9 which can occur in more than 50% of cases 10 . There were not found differences in regard to age, gender and ethnicity 9 .The lateral recess of the sphenoid sinus was evaluated in relation to the pterygopalatine fossa, and was classified in six types: type I, in which such recess is absent in the posterior fossa wall, type II, when the recess reaches above the vidian canal, type III with the recess engaged between the vidian and maxillary nerve canals, type IV, of alar pneumatization, type V, in which the root of the pterygoid process lodges the pneumatic expansion and type VI, of combined alar and pterygoid pneumatizations 11 . aBSTRaCT BaCKgROund. The pneumatization pattern of the sphenoid sinus seems rather unpredictable, as resulted from previous

Giant pneumatization of sphenoid sinus: Report of four cases and review of literature

“…Being widely use the Congdon (16) classification, several studies had found that the sellar type is the most prevalent pneumatization, follow by the presellar type and being the conchal type the least common (5,17). Agreeing with this classification, we observed the sellar type as the most frequent type of pneumatization (presented in all cases), followed by the presellar type (case 1 and 3), being less prevalent the conchal type (case 4 on the right side).…”

Incidental Discovery of Sphenoid Sinuses Agenesis: A Report of Two Cases in Benin, West Africa

“…Sometimes, pneumatization of the sphenoid sinuses extends to adjacent structures such as anterior clinoid processes, pterygoid processes, lesser and great wings of the sphenoid [13]. The greater the pneumatization of sinuses is, the more neurovascular structures burst into sinuses [14].…”

Anatomographic Variants of Sphenoid Sinus in Ethiopian Population

“…Patients were placed in the supine position with their chin hyperextended and scan plane angled perpendicular to the hard palate. Axial scans were performed from the maxillary sinus floor to the level of the frontal sinus roof, in a plane parallel with the hard palate [ 10 ]. Images were reviewed on the console with varying window levels and widths.…”

“…The paired sinuses generally develop asymmetrically, separated by the inter-sinus bony septum [ 7 , 9 ]. During childhood, maturation of the bone from red to yellow marrow takes place in the anterior part of the sphenoid bone [ 10 ].…”