Low-Dose Cone-Beam Computed Tomography for Assessment of Alveolar Clefts: A Randomized Controlled Trial in Image Quality.

Background: Children born with an alveolar cleft receive bone grafts for improved function and aesthetics. The cleft area is examined radiologically before and after bone graft. Optimizing radiographic 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 unilateral or bilateral alveolar clefts between 9 and 19 years (mean age, 9.5 years) were randomized 1:1 with either a ULD or an SD CBCT examination protocol. The CBCT scans were conducted with a Planmeca ProMax Mid scanner with an 8 × 5-cm 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 because of the lower radiation dose without compromising diagnostic information of CBCT images.

Clinical Question/level Of Evidence: Diagnostic, I.