Image shift of intracoronal pins viewed on bite-wing and panoramic radiographs

Pins were placed into dentin in molars and premolars in a dried mandible. Panoramic and bite-wing radiographs were obtained, and measurements of the images of pins on these radiographs were compared with measurements of the mandible. The bite-wing radiographs showed little distortion of the relative distance between pins. The panoramic radiographs showed magnification and parallax shift of images of pins; the distance between pins placed mesially and distally in a tooth was magnified maximally at the first molar, decreasing to the third molar. For pins related diagonally in a tooth, the image showed magnification and parallax shift so that the apparent distance between pins placed mesiobuccally and distolingually increased from bicuspid to third molar, whereas distobuccally and mesiolingually placed pins showed the reverse trend. Guidelines are given for the evaluation of bite-wing and panoramic radiographs that can give clinically valuable information about the positions of intracoronal features.