Compared to a round position-indicating device (PID), which of the following PIDs reduces patient radiation exposure by up to 70 percent?

The rectangular-shaped position-indicating device (PID) significantly reduces patient radiation exposure compared to a round PID. The main reason for this reduction is related to the geometry of the X-ray beam it produces. A rectangular PID is designed to match the shape of standard dental radiographic film more closely. This allows for better collimation of the X-ray beam to the area of interest, thereby minimizing the unnecessary exposure of surrounding tissues.

By focusing the beam more precisely, a rectangular PID can effectively limit the scatter radiation that contributes to overall patient dose, potentially reducing exposure by up to 70 percent. This is particularly advantageous in dental practices, where precise imaging is crucial and minimizing radiation to non-target areas is a priority.

In contrast, other shapes such as round or conical PIDs provide less targeted exposure control and may result in more radiation affecting areas outside the primary region of interest. This difference in design and function is key to understanding why the rectangular PID is favored for radiation safety in dental imaging.