LAUSR

BACKGROUND Children born with an alveolar cleft receive bone grafts for improved function and aesthetics. The cleft area is radiologically examined before and post bone graft. Optimizing x-ray examination protocols is essential to protect these patients from possible delayed radiation injury later in life. This study investigates whether image quality of cone-beam computed tomography (CBCT) exposed with an ultra-low dose (ULD) protocol is comparable to the clinical default protocol, the standard dose (SD) protocol, in visualizing details of importance in bone grafting of alveolar clefts. METHODS In this randomized controlled study, 72 patients with uni- or bilateral alveolar clefts between 9-19 years (mean age 9.5) were randomized 1:1 with either a ULD or an SD CBCT examination protocol. The CBCT scans were conducted with Planmeca ProMax Mid with an 8x5cm field of view. Two experienced radiologists blindly evaluated the images and visibility of cortical bone border, trabecular bone, tooth anatomy, root development, periodontal space, and cleft width. The visibility was categorized as unacceptable, acceptable, or excellent. RESULTS Mann-Whitney U test showed no significant differences in structure visibility between ULD and SD protocols regarding anatomical structures of interest: cortical bone border (p=0.07), trabecular bone (p=0.64), tooth anatomy (p=0.09), root development (p=0.57), periodontal space (p=0.38), and cleft width (p=0.44). CONCLUSIONS ULD and standard CBCT protocols provide comparable image quality in terms of structure visibility in the examination of alveolar clefts. The ULD protocol is preferred to the SD protocol due to the lower radiation dose without compromising diagnostic information of CBCT images.