Which type of imaging projection is used to visualize the sphenoid sinus through the open mouth?

The parietoacanthial projection, commonly known as the Water's view, is specifically designed to visualize the sphenoid sinus as well as other structures of the facial skeleton. This projection involves positioning the patient's orbitomeatal line (OML) at a specific angle to the imaging receptor, typically with the patient's chin extended and their mouth open. This technique enhances the visualization of the sphenoid sinus by allowing the X-ray beam to pass through the structures at an optimal angle, thereby minimizing superimposition from adjacent anatomical features.

Visualizing the sphenoid sinus effectively is crucial in diagnosing conditions such as sinusitis or other pathologies that might affect this area. In contrast, the other imaging projections listed, such as the lateral projection, submentovertex projection, and axiolateral projection, are utilized for different aspects of cranial and sinus imaging, focusing on other sinuses or spatial orientations that do not highlight the sphenoid sinus as clearly as the parietoacanthial projection does.