CBCT and Micro-CT Assessments of Trabecular Microstructure of Edentulous Mandible

Objective:  The aim of this study was to compare the microstructure of the trabecular bone of the edentulous anterior and posterior human mandible using cone- beam CT (CBCT) and micro CT (μCT). Method:  Twenty volumes of interests (VOIs) consisting of six anterior and fourteen posterior regions were obtained from sixteen human mandibular cadavers. A CBCT system with a resolution of 80μm and a μCT system with a resolution of 35μm were used to scan the mandibles. Three structural parameters (trabecular number, Tb.N; trabecular thickness, Tb.Th; and trabecular separation, Tb.Sp) were analysed using an image analysing software. Result: The independent sample t-test showed a significant difference for Tb.Th (p=0.023) between anterior and posterior edentulous regions by μCT but not for CBCT (p=0.092). There was no difference in Tb.N (p=0.580 for μCT and p=0.835 for CBCT) and Tb.Sp (p=0.381 for μCT and p=0.845 for CBCT) between the anterior and posterior regions. In the anterior region, the Pearson correlation was only significant between Tb.N and Tb.Sp (r= -0.874, p=0.023) for CBCT. In the posterior region, all correlations were significant for CBCT (r>0.678, p< 0.008) but was only significant between Tb.N and Tb.Sp for μCT (r= -0.845, p=0.001). Conclusion:  The CBCT measurements of the trabecular structural parameters in the anterior and in the posterior edentulous mandible in general are comparable to those obtained with μCT.