In a properly positioned Waters method projection of the sinuses with a horizontal beam, the petrous ridges appear just inferior to which sinuses?

In a properly positioned Waters method projection of the sinuses with a horizontal beam, the petrous ridges appear just inferior to which sinuses?

• A. Frontal sinuses
• B. Maxillary sinuses
• C. Ethmoid sinuses
• D. Sphenoid sinuses

Answer: (B)

In the Waters projection, the goal is to visualize the maxillary sinuses without the petrous ridges obscuring them. When the head is positioned correctly and a horizontal beam is used, the petrous ridges lie just inferior to the maxillary sinuses. This placement clears the maxillary sinuses so their contour and any pathology can be seen clearly. The reason this is the best fit is that the maxillary sinuses are the ones most effectively demonstrated in this view; their location is just beneath the orbits, and the technique is specifically tuned to pull the dense petrous bone away from overlapping them. Frontal sinuses sit higher up and are not the primary target of this view, while the sphenoid and ethmoid sinuses are positioned differently and often require other projections for optimal visualization.

In the Waters projection, the goal is to visualize the maxillary sinuses without the petrous ridges obscuring them. When the head is positioned correctly and a horizontal beam is used, the petrous ridges lie just inferior to the maxillary sinuses. This placement clears the maxillary sinuses so their contour and any pathology can be seen clearly. The reason this is the best fit is that the maxillary sinuses are the ones most effectively demonstrated in this view; their location is just beneath the orbits, and the technique is specifically tuned to pull the dense petrous bone away from overlapping them. Frontal sinuses sit higher up and are not the primary target of this view, while the sphenoid and ethmoid sinuses are positioned differently and often require other projections for optimal visualization.