BISECTING (SHORT-CONE) PERIAPICAL EXPOSURE TECHNIQUES

GENERAL

A short cone is used to take x-rays with bisecting angle exposure techniques. The target-film distance is 8 inches. The resulting image x-ray is somewhat larger using the short cone rather than using a long cone (see figure 4-1). The bisecting plane is halfway between the plane of the dental film and the longitudinal axis of the tooth. The average angle of projection is the angle between the occlusal plane and the angle of the central ray. The angle of the central ray is in relation to the bisecting plane.

Figure 4-1. Comparison of 8-inch and 16-inch target-film distances.