As Low Dose as Sufficient Quality: Optimization of Cone-beam Computed Tomographic Scanning Protocol for Tooth Autotransplantation Planning and Follow-up in Children.

INTRODUCTION: Tooth autotransplantation (TAT) offers a viable biological approach to tooth replacement in children. To enhance the outcome predictability of the TAT procedure, a cone-beam computed tomographic (CBCT)-based surgical planning and transfer technique has been developed. The aim of this study was to optimize the CBCT scanning protocol to achieve a dose as low as possible and to maintain sufficient image quality.

METHODS: A sectional head phantom (SK150; The Phantom Laboratory, Salem, NY) was scanned using 18 exposure protocols in 3 different CBCT machines: 3D Accuitomo 170 (Morita, Kyoto, Japan), ProMax 3D MAX (Planmeca, Helsinki, Finland), and NewTom VGI EVO (QR Verona, Verona, Italy). The effective dose (ED) was calculated using Monte Carlo simulation and pediatric voxel phantoms (5- and 8-year-old males and a 12-year-old female). Image quality was assessed by comparing segmented teeth volumes, evaluation of the visibility of the lamina dura, and morphologic surface analysis of 3-dimensional models. A general linear mixed model was fit to combine image quality parameters and radiation effective dose for each protocol in order to rank and compare the protocols examined in the study.

RESULTS: The ED for the preoperative scan can be reduced to the range of 74.6-157.9 μSv, with ProMax with ultra-low-dose high-definition reconstruction (Planmeca) 100 × 90 scoring the highest. The ED for the postoperative scan can be reduced to the range of 24.2-41.5 μSv with ProMax with ultra-low-dose normal-dose reconstruction 50 × 55 and NewTom 50 × 50 with the standard mode scoring the highest.

CONCLUSIONS: A considerable reduction in the pediatric ED can be achieved while maintaining sufficient image quality for tooth autotransplantation planning and follow-up using the dose optimization protocols.