Which paranasal sinuses are demonstrated by the SMV projection?

The SMV (Submentovertex) projection is specifically designed to visualize the sphenoid sinus and the ethmoid sinuses. In this projection, the patient's head is positioned so that the X-ray beam is directed from beneath the chin to the vertex of the skull, which allows for a clear view of the sinuses located deeper within the skull. This projection is particularly advantageous because it demonstrates the contour of the sphenoid sinus, assess its size, and provide a comprehensive look at the ethmoid air cells situated above it.

The other sinus groups do not fit as well into this projection’s view. For instance, the maxillary sinuses are primarily demonstrated on specific projections like the waters view. The frontal sinuses are best visualized using the Caldwell projection, which focuses more on the anterior aspect of the skull. The temporal bones do not have a direct representation in the SMV view as they are more lateral structures and not part of the paranasal sinuses assessed in this projection. Therefore, the SMV projection is optimal for displaying both the sphenoid and ethmoid sinuses effectively.