The petrous pyramids are in the lower third of the orbits during which projection?

• A. AP axial Towne
• B. PA axial Caldwell
• C. Lateral skull
• D. PA projection

Answer: (B)

Placing the petrous pyramids in the lower third of the orbits is achieved by a PA axial Caldwell projection. This view uses a caudal angulation of the central ray (about 15 degrees) so the dense petrous bones are nudged downward within the orbits. This positioning minimizes overlap with the orbital margins and frontal sinuses, giving a clearer view of the orbits and the vertical height of the orbital slopes. Other skull projections use different tilts or directions of the CR, which shifts the petrous pyramids away from that lower-orbit position, so they don’t produce the same arrangement.