Advantage of bisecting-angle technique?

• A. Reduced patient radiation
• B. Accurate tooth length
• C. Easier technique for all teeth
• D. Clear image of buccal surfaces

Answer: (B)

Distortion in a radiograph comes from not aligning the X-ray beam properly with the tooth and from how far the tooth is from the receptor. In the bisecting-angle technique, you place the receptor as close to the tooth as possible and aim the beam so it bisects the angle between the tooth’s long axis and the receptor. This setup reduces angular and magnification distortions, so the image height (and thus tooth length) on the film more accurately reflects the real tooth length. That makes accurate tooth length the main advantage of this method.

It doesn’t inherently reduce the patient’s radiation exposure, and it isn’t easier for all teeth since getting the correct angle can be tricky in some areas. It also doesn’t guarantee a clearer image of buccal surfaces, since distortion can still affect buccal–lingual dimensions depending on how the beam is angled.