Which projection is used to visualize the paranasal sinuses with mouth open?

Which projection is used to visualize the paranasal sinuses with mouth open?

• A. PA projection
• B. AP projection
• C. Open-mouth Waters projection
• D. Lateral projection

Answer: (C)

Opening the mouth while using the Waters projection creates a clearer path for the X-ray beam to pass through the sinus area, especially the sphenoid and posterior ethmoid sinuses. With the mouth open, the tongue drops away from the palate and the teeth are shifted from overlying the sinuses, reducing superimposition and allowing the paranasal sinuses to be seen more clearly. This view is specifically used when you want to visualize the sinuses with the mouth open. Other projections don’t facilitate this separation of structures, so they don’t provide the same level of visibility for the paranasal sinuses in this mouth position.

Opening the mouth while using the Waters projection creates a clearer path for the X-ray beam to pass through the sinus area, especially the sphenoid and posterior ethmoid sinuses. With the mouth open, the tongue drops away from the palate and the teeth are shifted from overlying the sinuses, reducing superimposition and allowing the paranasal sinuses to be seen more clearly. This view is specifically used when you want to visualize the sinuses with the mouth open. Other projections don’t facilitate this separation of structures, so they don’t provide the same level of visibility for the paranasal sinuses in this mouth position.