Comparison of micro-CT and cone beam CT on the feasibility of assessing trabecular structures in mandibular condyle

Objectives: To evaluate the accuracy of CBCT in assessing trabecular structures. Methods: Two human mandibles were scanned by micro-CT (Skyscan 1173 high-energy spiral scan micro-CT; Skyscan NV, Kontich, Belgium) and CBCT (3D Accuitomo 170; Morita, Japan). The CBCT images were reconstructed with 0.5 and 1mm thicknesses. The condylar images were selected for registration. A parallel algorithm for histogram computation was introduced to perform the registration. A mutual information (MI) value was used to evaluate the match between the images obtained from micro-CT and CBCT. Results: In comparison with the micro-CT image for the two samples, the CBCT image with 0.5mm thickness has a MI value of 0.873 and 0.903 while that with 1.0mm thickness has a MI value of 0.741 and 0.752. The CBCT images with 0.5mm thickness were better matched with micro-CT images. Conclusions: CBCT shows comparable accuracy with high-resolution micro-CT in assessing trabecular structures. CBCT can be a feasible tool to evaluate osseous changes of jaw bones.