Question

"what is the difference between parallel and bisecting technique"

Answer 1

In the paralleling technique, the beam alignment device is used to hold the receptor parallel to the long axis of the tooth. Examples of beam alignment devices include XCP (Extension, Cone, Paralleling) and BAI beam alignment devices (Rinn).

The bisecting technique or the bisecting-angle technique is one of the methods used to expose periapical images. The bisecting technique is developed based on the principle of “rule of isometry.” The rule of isometry states that if two triangles have equal angles and share a common side, those triangles are considered equal. In dental imaging, this principle is used to form two imaginary equal triangles.

The central ray in the correct bisecting technique is directed at 90 degrees (vertical) to the imaginary bisector. Correct vertical angulation results in the dental image with the same size as that of the real teeth.