Constructivism: a characteristic of the psychic process

The diagnostic accuracy of detailed zonography using the Scanora multimodal X-ray system was compared with that of periapical radiography. The study was based on the detection of periapical bone lesions at 259 dental sites distributed evenly throughout the dentitions of 164 patients. Each site was examined by periapical radiography and zonography, in parallel. The zonograms consisted of four detailed images that could also be read as stereopairs, in either the horizontal or vertical direction. Five observers evaluated the sites for the presence or absence of periapical osteolysis or sclerosis and apical widening of the periodontal ligament space for the whole dentition, and for three dental regions. ROC analysis revealed no significant overall or regional differences between the diagnostic accuracies of the periapical and zonographic techniques, regardless of whether the zonograms were read as sets of four images (multiview) or stereoscopic images. The sensitivity of periapical radiography was 72%, that of multiview zonography 88%, and that of stereoscopic zonography 85%. Specificities were 93%, 84% and 89%, respectively. The energy imparted during detailed zonography was 0.98 mJ. It is concluded that zonography is as good as periapical radiography for the detection of periapical pathology.