Cephalometric regional superimpositions -- digital vs. analog accuracy and precision : 1. the maxilla

Introduction: The purpose of this study was to measure the displacement of defined dental structures, as a result of superimposition of cephalometric images across paired time-points by both digital and analog methods. The magnitudes of such displacements across three methods of superimposition were compared to each other and to a reference method constructed by registering superimposed cephalometric images on tantalum markers implanted in the study participants\u27 maxillae. The defined dental structures were: 1) First molar mesial contact point; 2) First molar apical root bisection; 3) Central incisor root apex; 4) Central incisor crown incisal edge. Methods: Lateral cephalograms of 22 patients containing tantalum implants from the Mathews acquisition group were digitized, traced and superimposed using analog (implant and structural) and digital (Dolphin and QuickCeph) methods. Superimpositions were exported to Adobe Photoshop where they were scaled and displacement of defined dental landmarks measured using a Cartesian coordinate system. A random-effects, generalized linear model with Bonferroni adjustment was used to compare the different methods. Results: The structural method (p \u3c 0.01) showed statistically significant differences versus the implant method and demonstrated the smallest 95% confidence interval range compared to Quick Ceph and Dolphin (0.45mm, 0.75mm, and 0.95mm, respectively). The four structural method landmarks demonstrated statistically significant differences versus the implant method (