Three-dimensional reconstruction of the temporal bone: Comparison of in situ, CT, and CBCT measurements

Objective: To evaluate the accuracy of three-dimensional (3D) Cone Beam Computed Tomography (CBCT) and Computed Tomography (CT) reconstructions of human temporal bones compared with in situ measurements. Material and methods: Experimental anatomical study of 10 human temporal bones. Wilcoxon's test was used to compare 8 distances on each temporal bone measured in situ and then on 3D CT and CBCT reconstructions. Six landmarks were used: external auditory canal (EAC), tip of the mastoid process, tip of the occiput, zygoma, a point situated 1 cm above the tip of the mastoid process (TO) (open technique: lower limit of the mastoidectomy), head of stapes. Results: No significant difference was observed between the 3 measuring techniques for any of the distances studied (P > 0.05). Discussion: This study demonstrates the equivalence of CBCT and CT for temporal bone measurements. Conclusion: CBCT is a new imaging modality providing 3D reconstructions of the temporal bone that are as reliable as those obtained by CT. As a result of better spatial resolution compared to CT, CBCT is associated with a significantly lower radiation dose. This technique constitutes a morphological progress, as CBCT is comparable to CT, allowing investigation of pathological ears with a lower radiation dose. (C) 2018 Elsevier Masson SAS. All rights reserved.