Comparative study of implant site assessment using CBCT, tomography and panoramic radiography

Aim: The present study was done to evaluate the accuracy of panoramic radiography (OPG), conventional cross sectional tomography (CCST) and cone beam computed tomography (CBCT) to precisely portray structures in the posterior mandible. Materials and Methods: The present in-vitro study was performed on 42 edentulous human mandibles. A region 2cm behind the mental foramen was imaged using an OPG machine followed by imaging the same region using CCST function of the same OPG machine and CBCT. The distances from the alveolar crest to superior margin of the mandibular canal and alveolar crest to the lower border of mandible were measured in radiographs obtained by the three modalities. This step was followed by the comparison of the measurements performed in the cut-section of the mandible considered as Gold Standard. Results: The measurements done in the images obtained by OPG machine exceeded the values of gold standard by a mean of 2.69 mm ± 2.27 mm and 5.84 mm± 0.89 mm respectively. Similarly in CCST function and CBCT images, the measurements exceeded by 4.95 mm ± 2.35mm, 9.55mm ±1.25mm and 0.24mm ±0.20mm, 0.20mm ± 0.13mm respectively. The differences between the measurements made in radiographs and cut section were statistically significant. Conclusions: It was concluded that the measurements made by CBCT images were more precise, in addition CBCT images were also helpful in accurate three dimensional localization of the mandibular canal.