Which structure is NOT seen in standard Occipitomental (Water's) view

Ans. is 'B Posterior ethmoidal and cannot be visualized. Hence single best answer is posterior ethmoidal sinus. First read these lines from Burrow & Leeds " Occipitomental (Water's) projection: was developed more than 50 years ago by an ENT surgeon, as a modification of the original PA view of the skull, to examine the maxillary antrum and other accessory sinuses. It provides the only linen cohered view of the antra , which are projected above the petrous pyramids. The view of the bony orbits is second only in value to that given by the Caldwell's view. Only in this projection are the ethmoidal cells separated: the anterior ones are projected above, the posterior ones below."