An in vitro study to evaluate the accuracy of orthopantomograph as an aid to determine condylar guidance

PURPOSE: The study was conducted to evaluate the accuracy of orthopantomograph (OPG) as an aid to determine condylar guidance. METHODOLOGY: The condylar guidance was measured using the impressions of glenoid fossae and radiographs (OPG) on thirty dried human skulls. Frankfurt horizontal plane (FHP) was used as a reference plane in both the methods and wire markers were adapted to make the contours of glenoid fossae discernible for both the methods. The condylar inclination angle was measured between FHP and a line joining the most concave point on the glenoid fossa with the most inferior point on the articular eminence on both right and left sides. RESULTS: Pearson correlation was used for statistical analysis, and it showed a strong correlation between anatomic and radiographic methods (r = 0.864 for the left side, r = 0.873 for the right side) as well as between right and left sides (r = 0.830). The data were also subjected to regression analysis (linear and panel estimation approach) which showed that OPG could be effectively used to predict the condylar guidance (r(2) = 0.6160). CONCLUSION: Although OPG shows a higher value than anatomic method, it can be used as an aid to set condylar guidance on semi-adjustable articulator.