Methods: Among patients reffered to Hamadan dental school having both digital panoramic radiograph (Digora) and CBCT (New Tom), 29 patients were found. Two patients were excluded from the study because of tooth loss. Maximum width and length of mandibular teeth No. 36,34,33,31,41,43,44, 46 were measured in digital panoramic views using Digora software and in CBCT reformatted panoramic views and also in axial view of CBCT with NNT software. MANOVA test and Post Hoc and Tukey were used for statistical analysis.
Results: There were a significant difference in both width and length of teeth between group 1 and 3 ,and group 1 and 2 (P value< 0.05). In group 1 the maximum magnification was observed in incisor and the minimum in molar tooth. There were no statistical differences in width and length between group 2 and 3 except incisor width (P value> 0.05). Left and right teeth had not shown any significant size difference in each image modalities.
Conclusions: CBCT reformatted panoramic shows generally more accurate tooth size than digital panoramic. In this image only the width of incisor teeth had shown magnification relative to 3D image.