Normal Anatomical Variations of Maxillary Sinus Septa using Computerized Tomography from Benghazi – Libya

Maxillary sinus septa are bony crests within the sinuses and are referred to as Underwood's septa, because they were first described in detailed anatomy of the maxillary sinus by Underwood in 1910. [1] Even though, Underwood published a detailed description of maxillary sinus anatomy (antrum of Highmore) and classified them into anterior (between the second premolar and first molar), middle (between the first and second molar), and posterior (distal to the third molar). [1,2] Krenmair. [3] further classified the sinus septa into primary and secondary; the primary septa occur along with the development of the maxilla, while the secondary arises as a result of irregular pneumatization of the sinus floor after tooth loss,. Several authors have studied the etiology of maxillary sinus septa. [1-3] Neivert. [2] Proposed that septa were derived from finger-like projections produced by the embryonic out-pouching of the ethmoidal infundibulum. For decades these septa were considered clinically-insignificant anatomical variations but now it’s important to understand the maxillary sinus and its anatomical variations. [1,4] The presence of anatomic variations within the maxillary sinus, such as septa, may increase the risk of schneiderian membrane perforation during sinus operations and this represents the most common complication. [5, 6] As such, a detailed knowledge of the anatomy of the sinuses is critical in performing procedures such as functional endoscopic sinus surgery [7].