Which of the following statements is true about the SMV projection?

• A. Vertical beam
• B. Oblique beam
• C. Lateral beam
• D. Horizontal beam

Answer: (D)

In the SMV projection, the central ray is directed horizontally. This horizontal beam travels from a point beneath the chin (submentum) up to the vertex of the skull, passing through the mandible and the base of the skull in a single, level plane. Extending the beam horizontally is essential to capture the intended submentovertex view and to minimize distortion or overlap from other structures. If the beam were vertical, oblique, or from the side, the image would not show the same relationships of the mandible, zygomatic arches, and skull base, and the projection wouldn’t be the SMV view. So the statement describing the beam as horizontal is the accurate one.