Evaluaton of Vertical Magnification Panoramic Radiogarphy Compared to CBCT Base on Anatomical Location

Currently, dental implant is one of the most modern approaches to teeth replacement. Panoramic radiography is considered as the prerequisite for implant therapy. The purpose of the present study was to investigate the vertical magnification of digital panoramic images in various anatomic parts of the mandible. A total of 30 patients referred to Sajjad Radiography Center for implant therapy with high quality images of both panoramic radiography and CBCT were selected. The panoramic images were acquired with Prolin EX set and the CBCT images were recorded via Planmeca ROMEXIC2.9.2.R. Specific areas of panoramic images with certain anatomic structures were considered. The vertical distance between two desired points A and B were measured in the panoramic radiography and compared to CBCT images. In this way, the magnification index of panoramic radiography was obtained. Measurements were calculated in four areas including posterior maxilla, posterior mandible, anterior maxilla, and anterior mandible. Based on the statistical findings of the study, the rate of panoramic radiography magnification compared to CBCT was 21% in the anterior and 13% in the posterior regions, that showed a statistical significant difference(P<0.001). Also, the proportion of mean magnification of panoramic radiography to CBCT was 1.18 in maxilla and 1.16 in mandible, and there was a statistical significant difference(P<0.001). Based on the results of statistical testes, there was interaction between anterior-posterior and inferior-superior. In the case of application of panoramic images in implant placement, the site factor of the implant, being in the maxilla or mandible and in the posterior or anterior, should be considered.