Which technique requires the receptor to be placed very close to the tooth surface and not parallel to it?

• A. Bisecting-Angle Technique
• B. Paralleling Technique
• C. Occlusal Technique
• D. Reverse Technique

Answer: (A)

The setup described focuses on how to control image distortion when you can’t place the film parallel to the tooth. When the receptor sits very close to the tooth and is not parallel to it, you’re using a bisecting-angle approach. The key idea is that the central ray is directed so it bisects the angle formed between the tooth and the receptor. This geometry allows a workable image even with limited space or challenging anatomy, because the film is pressed against the tooth and you angle the beam to match that angle.

This technique is favored when parallel placement isn’t feasible due to anatomical constraints like a shallow palate or prominent tori, where trying to keep the receptor parallel would distort or prevent proper image capture. It’s more technically demanding because small changes in angulation or film position can cause distortion, but it’s the method that fits the description of placing the receptor very close to the tooth and not parallel to it.

In contrast, the parallel technique keeps the receptor away from the tooth and precisely parallel to the tooth’s long axis, with the beam directed perpendicular to the film to minimize distortion. The occlusal and reverse techniques involve different film placements and viewing orientations for specific imaging goals, not the close, non-parallel setup described here.