What occurs as the target-film distance is increased by using a long PID?

Increasing the target-film distance by using a long position-indicating device (PID) reduces distortion in dental radiography. When the target (the x-ray tube) is further away from the film (the detector), the x-ray beam diverges less by the time it reaches the film. This greater distance results in more parallel x-ray rays that impact the film, ultimately leading to improved image clarity and reduced geometric distortion.

Less distortion is particularly vital in dental radiography because it ensures that anatomical structures are represented more accurately. A well-defined image assists in diagnosis and treatment planning, making it essential to maintain proper film geometry. The reduction of distortion as a result of increasing the target-film distance helps capture the true size and shape of dental anatomy, which can significantly influence clinical outcomes.