sphenoidal sinus
sphenoidal sinus
One of the paired paranasal sinuses, located in the body of the sphenoid bone and communicating with the highest meatus of the nasal cavity on the same side[MESH]. The sphenoidal sinuses (or sphenoid) contained within the body of the sphenoid vary in size and shape; owing to the lateral displacement of the intervening septum they are rarely symmetrical. The following are their average measurements: vertical height, 2.2 cm. ; transverse breadth, 2 cm. ; antero-posterior depth, 2.2 cm. [WP,unvetted].