OBJECTIVES: To evaluate the tooth image measurements according to the tooth location and to calculate the magnification rate for comparison and analysis in digitalized panoramic and cone beam computed tomographic (CBCT) images. METHODS: A diagnostic template was fabricated and delivered on the preimplant sites. A 5-mm gutta-percha cone or a metal ball was inserted in the coronal part of each tooth. Panoramic images were obtained with Ortho stage (AUTO III N CM; Asahi, Japan) or Promax (Planmeca, Helsinki, Finland) and CBCT images were obtained with PANORAMIC CT (PSR9000N; Asahi) for each patient and the same region. The vertical length of the gutta-percha cone or the metal ball was measured and compared with the panoramic and CBCT images according to the tooth location. Magnification rate was compared between the 2 types of panoramic machines. RESULTS: About 1.09 to 1.28 magnification occurred in panoramic images, depending on the tooth location. The magnification rate was significantly different between the panoramic machines (Ortho stage, 1.27; Promax. 1.17). Almost no magnification of images occurred in CBCT images with no difference to the tooth location. CONCLUSIONS: In panoramic radiography, it is inappropriate to apply a general magnification ratio covering the whole image. For a more accurate implant surgery, the use of a metal ball or a premeasured gutta-percha cone on the preimplant site as standard measurement is recommended. However, in recently introduced CBCT, magnification of images did not occur, allowing it being used for accurate clinical procedures.
OBJECTIVES: To evaluate the tooth image measurements according to the tooth location and to calculate the magnification rate for comparison and analysis in digitalized panoramic and cone beam computed tomographic (CBCT) images. METHODS: A diagnostic template was fabricated and delivered on the preimplant sites. A 5-mm gutta-percha cone or a metal ball was inserted in the coronal part of each tooth. Panoramic images were obtained with Ortho stage (AUTO III N CM; Asahi, Japan) or Promax (Planmeca, Helsinki, Finland) and CBCT images were obtained with PANORAMIC CT (PSR9000N; Asahi) for each patient and the same region. The vertical length of the gutta-percha cone or the metal ball was measured and compared with the panoramic and CBCT images according to the tooth location. Magnification rate was compared between the 2 types of panoramic machines. RESULTS: About 1.09 to 1.28 magnification occurred in panoramic images, depending on the tooth location. The magnification rate was significantly different between the panoramic machines (Ortho stage, 1.27; Promax. 1.17). Almost no magnification of images occurred in CBCT images with no difference to the tooth location. CONCLUSIONS: In panoramic radiography, it is inappropriate to apply a general magnification ratio covering the whole image. For a more accurate implant surgery, the use of a metal ball or a premeasured gutta-percha cone on the preimplant site as standard measurement is recommended. However, in recently introduced CBCT, magnification of images did not occur, allowing it being used for accurate clinical procedures.