Accuracy of CBCT Linear Measurements in Orthogonal versus Corrected Coronal Planes
Remy Golding1*, Laurence J Walsh2, Paul Monsour3
Journal Title: Journal of Dental Health and Oral Research
Objectives: To assess the accuracy of measurements between a simulated tooth root and Inferior Dental Canal (IDC) in medium field-of-view Cone Beam Computed Tomography (CBCT) scans, comparing orthogonal plane measurements with views ‘corrected’ perpendicular to the IDC.
Study Design: Sixteen CBCT scans were acquired, including equally 0.2 mm and 0.4 mm resolutions and two machines. Distances between root and IDC of 1-3 mm (horizontal and vertical) and 0.5 mm (horizontal) were measured with Radiant DICOM viewer. Retest reliability was assessed for 80 sites.
Results: High retest reliability was demonstrated (limits of agreement -0.33 mm [(-0.42) – (-0.25)] to 0.28 mm [0.19 – 0.36]). Uncorrected maximum over-estimation was 0.74 mm, and median was -0.02 mm (SD 0.21). Corrected maximum over-estimation was 0.64 mm, and median was -0.04 mm (SD 0.19). The difference in medians was found to be statistically significant (p = 0.006, d = 0.26). Uncorrected measurements were larger than corrected by greater than 0.5 mm in seven instances (maximum difference of 0.77 mm), and smaller by greater than 0.5 mm in two instances (maximum difference of 0.64 mm).
Conclusions: Idealised CBCT measurements can achieve sub-millimetre accuracy. Corrected view measurements may reduce the risk of distance over-estimation. Further prospective research using patient data is warranted.