Accuracy of cone-beam computed tomography at different resolutions assessed on the bony covering of the mandibular anterior teeth

Impact of Voxel Size Variation on CBCT-Based Diagnostic Outcome in Dentistry: a Systematic Review

“…Patcas and colleagues [11] (evaluating both bone height and width) showed that 0.4-mm voxel images provided results as accurate as 0.125-mm voxel images. This finding is also in agreement with Torres and coauthors [33], who did not find differences between voxel sizes of 0.2, 0.3, and 0.4 mm, when evaluating linear bone measurements.…”

“…When it was equal or smaller than the voxel size, the distance was underestimated. For bone walls thinner than the voxel size, measures from both tested voxel sizes were different from the gold standard Patcas et al [11] One observer measured the images, in duplicate. Digital caliper measurements were the gold standard Both voxel resolutions were accurate compared to the gold standard, but the 99 % confidence interval for the absolute measurement error was higher in the lower resolution images Torres et al [33] One observer measured the images, in duplicate.…”

“…The remaining eight studies were based on numerical outcomes measured in the images. Three studies measured 3D surface reconstructions [17,30,31] (and used micro-CT of the teeth as the gold standard), two measured the height and thickness of alveolar bone [11,32], one assessed linear bone measurements (distance between established anatomical landmarks) [33], one measured the thickness of the soft tissue of the face [34], and one measured tooth and root length [35], and these last five studies used caliper measurements of the skulls as the gold standard. Six studies further compared the CBCT images in different resolutions to images acquired using intraoral radiographic systems [18,21,[25][26][27]35].…”

“…It was common in the studies that FOV and voxel size were evaluated together. It is known that larger FOVs may provide less sharp reconstructions because of the greater beam angulation in the superior and inferior volume area and reduced contrast-to-noise ratio [11]. In this review, included studies focused on voxel size, rather than the FOV size.…”

“…Images acquired in smaller voxel sizes, although "prettier" and sharper from a subjective point of view [9], will increase the radiation dose to the patient but might provide the same diagnostic outcome as lower resolution images [10]. Thus, it is important to ponder that the comparison of CBCT examinations with various voxel settings is relevant to understand the impact of the inherent image quality on the reliability and accuracy of the diagnostic outcome [11].…”