Objective: To assess the reliability of inter-radicular measurements taken using dental pantomograms (DPT), long cone periapical radiographs (LCPA) and cone bean computed tomography (CBCT).
Materials/methods: A typodont simulating a hypodontia patient undergoing fixed appliance treatment was used. LCPAs, DPT, I-CAT and Accuitomo CBCT images were taken and the distances between the edentulous spans were measured at the midpoint of the roots and the cemento-enamel junctions (CEJ) of adjacent teeth. The results of each modality were compared to each other to the actual inter-radicular space.
Results: The DPT overestimated inter-radicular widths by 2 mm or more [mean: 2.48; 95% confidence interval (CI): -1.09 to 6.05 mm]. The LCPA overestimated the inter-radicular widths by 1.5 mm with a 95% CI of -0.095 to 4.03 mm. The mean differences between gold standard (model) and Accuitomo was 0.57 mm (95% CI: -0.37 to 1.51 mm) for the root mean and 0.22 mm (95% CI: -0.52 to 0.96 mm) for the CEJ. This was similar to the differences between the model and I-CAT where the inter-radicular root mean difference was 0.38 mm (95% CI: -0.38 to 1.14 mm) and the CEJ mean difference was 0.21 mm (95% CI: -0.50 to 0.92 mm).
Conclusion: The CBCT overestimated the root distance by 0.48 mm and the CEJ width by 0.22 mm, which is clinically irrelevant for implant placement. The DPT overestimated inter-radicular width by 2 mm and the LCPA by 1.5 mm and this difference may put roots of adjacent teeth at risk during implant placement.
Keywords: Inter-radicular width measurements; Radiographic technique.