The frontal sinuses show the most anatomic variation such as congenital absence or hypoplasia (Fig. 1). The sphenoid sinuses, located posteriorly, form last. Anatomy of Sinuses-Artist's Rendition.

Endoscopy provides a mechanism to accurately visualize disease within the maxillary or sphenoid sinus for definitive ... anatomy and its important anatomic variants. Bony changes may occur as ...