Accuracy of Cone Beam Computed Tomography in Volumetric Evaluation of the Mandibular Condyle

Abstract

Introduction:The final size of the mandible and several malocclusions are significantly influenced by the condyle. Recently, there has been a lot of interest in using CBCT imaging to evaluate condyle shape and volume. In order to suggest its use in clinical decision-making, it is required to confirm that the information received from CBCT is accurate and trustworthy for measuring condylar volume. Aim: To assess the precision of cone-beam computed tomography's volumetric analysis of the mandibular condyle (CBCT) in comparison with real physical volumetric measurements (gold standard). Materials and Methods: The present study was conducted on 6 dry human mandibles including 12 condyles. Volumetric measurements of each condyle were carried out using CBCT by automatic segmentation. A replica model of the condyle was obtained and utilized to evaluate the condyle's actual physical volume using the water displacement method (gold standard). The radiographic volumetric measurements of the condyles were compared to the real volumetric measurements and assessed for accuracy. Results: Condylar real physical and CBCT volumetric measurements showed very good intra and inter observer agreement. Condylar volume assessment showed higher CBCT values in comparison to the physical ones with a mean error = 0.34 cm 3 , denoting an overestimation in CBCT readings =17.74 %. Despite the fact that the mean physical and CBCT measures were statistically different, the correlation coefficient (r) showed a strong direct correlation between physical and CBCT volume estimations. Conclusion: CBCT volumetric measurements using automatic segmentation is a reproducible, fast and feasible method for volume segmentation of mandibular condyles. However, for application in the dental office, clinicians should be cautious when planning treatment procedures involving condylar volume assessment since CBCT tends to significantly overestimate the obtained measurements.