Accuracy of cone beam computerized tomography and a three-dimensional stereolithographic model in identifying the anterior loop of the mental nerve: A study on cadavers

The objective of this ex vivo cadaver study was to determine the accuracy of cone beam computerized tomography (CBCT) and a 3-dimensional stereolithographic (STL) model in identifying and measuring the anterior loop length (ANLL) of the mental nerve. A total of 12 cadavers (24 mental nerve plexus) were used for this study. Standardized CBCT scans of each mandible were obtained both with and without radiographic contrast tracer injected into the mental nerve plexus, and STL models of the two acquired CBCT images were made. The ANLL were measured using CBCT, STL model, and anatomy. The measurements obtained from the CBCT images and STL models were then analyzed and compared with the direct anatomic measurements. A paired sample t test was used, and P values less than .05 were considered statistically significant. The mean difference between CBCT and anatomic measurement was 0.04 mm and was not statistically significant (P = .332), whereas the mean difference between STL models and anatomic measurement was 0.4 mm and was statistically significant (P = .042). There was also a statistical significant difference between CBCT and the STL model (P = .048) with the mean difference of 0.35 mm. Therefore, CBCT is an accurate and reliable method in determining and measuring the ANLL but the STL model over- or underestimated the ANLL by as much as 1.51 mm and 1.83 mm, respectively.