Implementation of ultra-low-dose CBCT for routine 2D orthodontic diagnostic radiographs: Cephalometric landmark identification and image quality assessment

Abstract

Since its adoption more than two decades ago in the field of dentistry, three-dimensional (3D) cone-beam computed tomography (CBCT) has rapidly gained popularity as an imaging tool for three-dimensional visualization, diagnosis, and treatment simulation. The objective of this two-part study was to assess landmark identification, as well as the diagnostic value of images obtained using an ultra-low-dose reduced projection (sparse) views algorithm Adaptive-Steepest-Descent-Projection-Onto-Convex-Sets (ASD-POCS) applied to existing dental CBCT data. ASD-POCS was developed for CBCT studies, producing multiple CBCT data files with 12.5% (39), 25% (76), and 50% (150) of the original number of projection views (which is in direct proportion with the lowering of radiation dose). Assessment of 2D landmark identification derived from CBCT data at different projection views was conducted. Assessment of diagnostic quality was studied by evaluating radiographs of various projection views on a visual analog scale by different dental specialists. In conclusion, this study found no statistically significant differences in the quality of images at 25% (76) projection views as compared to 100% (300) projection views. The implementation on ASD-POCS algorithm by the CBCT manufacturers in the future may be beneficial for clinicians in reducing the amount of patient radiation exposure when obtaining routine orthodontic diagnostic radiographs.