Figure 1-25. - Relationship of central ray, tooth, and film packet in bisecting-angle technique.

GUIDELINES FOR TAKING PERIAPICAL RADIOGRAPHS, BISECTING-ANGLE TECHNIQUE

Take the same 14 radiographs using the same exposure sequence as that discussed for the paralleling technique. Complete the following steps:

1. Program the X-ray machine for the discussed mA and kVp settings. The exposure time varies, just as it did with the paralleling technique. Refer to the film

Maxillary Mandibular Incisor Cuspid Bicuspid Molar +40 to +45 +45 to +50 +30 to +35 +20 to +25 Incisor -15 to -20 Cuspid -20 to -25 Bicuspid -10 to -15 Molar -5 to 0

DTV2F126

Figure 1-26. - Average vertical angulation.

Figure 1-27. - Elongated image.

Figure 1-28. - Foreshortened image.

Figure 1-29. - Correct and incorrect cylinder direction.

manufacturer's instructions for correct time/impulse settings. Remember to reduce the kVp by 5 when taking radiographs in edentulous areas, and to 70 when taking radiographs on children.