Computer measurement of image shift of intracoronal pins viewed on bite-wing and panoramic radiographs

Abstract

Background: The image shift can be measured from a combination of bite-wing and panoramic radiographs, so the aim of this study was measuring the relative image shift of intracoronal pins viewed on bite-wing and panoramic radiographs by using computer.Material and methods: Sixteen pins were placed in the dentin of three molars and one premolar on the left side of a dried mandible. Panoramic and bitewing radiographs were obtained.Results: Measurements of the image of pins on the radiographs were obtained by using special computer software and these measurements were compared with measurements on the mandible.Conclusion: The bite-wing radiograph shows little distortion of the relative distances between pins. In panoramic radiograph magnification and parallax shift of the pin images were obtained. The horizontal magnification of interpin images between pins placed mesially and distally was greatest at the third and least at the first molar. For diagonally related pins in a tooth the images showed magnification and parallax shift so that the relative distance between pins placed mesiobuccally and distolingually increased from premolar to third molar, where as distobuccally and mesiolingually placed pins showed reverse trend.