Which projection best demonstrates the maxillary sinuses?

The parietoacanthial projection, often referred to as the Waters view, is the best choice for clearly demonstrating the maxillary sinuses. This projection is specifically designed to allow visualization of the maxillary sinuses in their entirety. By positioning the patient so that the orbitomeatal line (OML) is perpendicular to the image receptor and directing the central ray to enter at the acanthion, this view minimizes superimposition from other cranial structures and maximizes clarity of the sinuses.

In addition to providing a clear view of the maxillary sinuses, the Waters view also reveals the relationship of the sinuses to other anatomical structures, such as the nasal cavity and the orbits. This is crucial for both diagnostic purposes and treatment planning. The angling of the x-ray beam in this projection optimally demonstrates the sinus spaces without obstruction from adjacent structures, which makes it superior to other projections in assessing the maxillary sinuses.

Other projections, while useful for different anatomical imaging, either do not provide as clear a view or do not focus specifically on the maxillary sinuses. For instance, the SMV (submentovertex) projection primarily visualizes the cranial base and is more suited for examining the sphenoid