Comparison of four panoramic dental radiographic systems for tooth angulation measurement accuracy under different tolerances

Panoramic radiographs of a dry skull were used to evaluate the accuracy of four panoramic dental X-ray systems in determining tooth angulations in the buccal segments. The four machines evaluated were the Philips Oralix pan DC, the GE panelipse, the SS White panorex 1, and the SS White panorex 2. Panoramic radiographs were taken at six different patient positions for each machine to evaluate the effects of patient positioning on determining tooth angulations in the buccal segments. All of the machines studied showed a significant correlation between the mean radiographic estimates and the actual measurements regardless of positioning (p<0.05). With correct placement of the skull, the results were analyzes for an error tolerance of ±30 between the actual measurements and the radiographic estimates for tooth angulation. The SS White Panorex 1 was accurate 74% of the time, the GE Panelipse was accurate 67% of the time, the Philips Oralix Pan DC and the SS White Panorex 2 were accurate 64% of the time. When an error tolerance of ±50 was permitted, the accuracy was 89% for the SS White Panorex 1 and the GE Panelipse, 85% for Philips Oralix Pan DC, and 81% for the SS White Panorex 2.