Evaluation of radiographic magnification in lateral cephalograms obtained with different X-ray devices: experimental study in human dry skull.

OBJECTIVE The purpose of this study was to evaluate the influence of the magnification factor of the radiographic image in angular, linear and proportional measurements. METHODS From a dried human skull where metallic spheres with predetermined size were fixed (1.0 mm), 14 radiographs were obtained in devices from three different manufacturers: Panoura, Instrumentarium and Tomeceph. The Pearson correlation test was used to investigate the relationship between the rate of radiographic magnification and the cephalometric measurements assessed. RESULTS According to the results, the linear measurements showed a high positive correlation, pointing out great influence of the magnification factor, while the angular and proportional measurements did not correlate. CONCLUSIONS Comparisons between linear cephalometric measurements obtained with different devices from the same manufacturer showed maximum rates of expansion of 0.6%, 1.25% and 2.3%, respectively, for the devices from Instrumentarium (OP-100, Instrumentarium, Finland), Panoura (10CSU, Yoshida, Japan) and Satelec/Tomeceph (XMind, Satelec/Tomeceph Orion Corporation, Finland).