Use of experimental phantoms to determine the accuracy and reliability of mandibular cortical width measurements by panoramic radiography and cone-beam computed tomography.

The present study used an aluminum phantom to calculate accurate vertical magnification values around the mental foramen on panoramic radiography (PR) and compared corrected PR (Cor-PR) thickness measurements of the aluminum phantom and mandibular cortical width (MCW) of the human head with cone-beam computed tomography (CBCT) measurements at two fields of view (FOVs). The calculated vertical magnification value for PR around the mental foramen was 1.37. Measurements of the aluminum phantom significantly differed between Cor-PR and CBCT with an FOV of 100 mm and between CBCT with FOVs of 40 and 100 mm; however, MCW measurements did not significantly differ among the three methods. There was a very strong correlation between Cor-PR and CBCT with an FOV of 40 mm and between CBCT with FOVs of 40 mm and 100 mm, and intraobserver and interobserver agreement was good-to-excellent for all methods. These results suggest that Cor-PR and CBCT with small and large FOVs are acceptable for measuring MCW.