Comparison of Two Cone-Beam Computed Tomography Systems Regarding Linear Measurement Accuracy for Implant Sites in the Mandible: An In-Vitro Study

There are critical areas in the mandible that should be considered during implant placement such as inferior alveolar canal, mental foramen, and the root of the adjacent tooth. Two-dimensional images obtained from periapical, panoramic, and conventional tomography are considered in the evaluation of implant placement and bone quality. Cone-beam computed tomography (CBCT) is a new imaging technique, which is superior to other methods from different aspects. Thus, we aimed to compare the accuracy of two different CBCT systems (i.e., Promax 3D and Newtom 3G) in measuring the anatomic distances in the mandible.
In this experimental study, six dry mandibles were used for measuring the width and height of mandible in six areas. Also, caliper was used as the gold standard and the distances were marked by barium sulfate as a radiopaque material. Then, the mandibles were scanned with the two CBCT systems, and the distances were measured by two observers (oral and maxillofacial radiologists) under homogenous conditions by using their respective software. The obtained results were evaluated by multivariate ANOVA and compared with the gold standard.
The accuracy of both CBCT systems (in all the three FOVs) was close to that of collies in measuring the height of mandible. The accuracy of Promax 3D was closer to collies in evaluating bacco-lingual width, and it was more accurate than Newtom 3G (in all the three FOVs; P The results of this study showed that Promax 3D and Newtom 3G techniques (in all the three FOVs) have millimeter precision and are capable of measuring the lengths and widths needed to establish the treatment plan.