DPA projection utilizing a 15° OML adjustment from the horizontal is used to demonstrate which sinus groups?

• A. Sphenoid and maxillary
• B. Frontal and ethmoid
• C. Maxillary only
• D. Frontal only

Answer: (B)

The DPA (Dental Panoramic Radiography) projection utilizing a 15° OML (Orbitomeatal Line) adjustment from the horizontal is particularly effective for demonstrating the frontal and ethmoid sinus groups. When the OML is angled downwards, this projection opens up the sinuses in a way that provides greater clarity and detail, allowing for optimal visualization of the frontal sinuses, which are situated in the forehead area, and the ethmoid sinuses, located between the eyes.

This specific angulation helps in reducing the superimposition of the surrounding anatomical structures, thus enhancing the diagnostic capability of the radiograph. By positioning the patient's orbitomeatal line at this angle, it aligns the central ray more favorably to capture these sinus areas without distortion, making it crucial for demonstrating frontal and ethmoid sinuses clearly. Therefore, the DPA projection at a 15° OML adjustment effectively facilitates the assessment of these particular sinus groups.