Ultra-low-dose cone-beam CT for cleft and craniofacial deformity surgery: radiation reduction and clinical applicability

Patients with cleft lip and palate and other craniofacial deformities often require repeated imaging during growth, making radiation reduction a priority. Cone-beam computed tomography (CBCT) offers lower radiation exposure than conventional CT, and ultra-low-dose (ULD) protocols may further reduce dose while maintaining clinical usability for surgical planning. This retrospective cohort study evaluated whether ULD CBCT provides comparable clinical usability to standard-dose CBCT for virtual surgical planning (VSP) and patient-specific implant (PSI) design in children and young adults undergoing orthognathic surgery for pediatric-onset craniofacial conditions. Forty consecutive patients with pediatric-onset craniofacial anomalies (23 unilateral cleft lip and palate, 10 bilateral cleft lip and palate, and 7 other craniofacial deformities) who underwent PSI-based orthognathic surgery were included. The primary predictor was the CBCT protocol (standard-dose FACE vs. ULD JAW), selected in routine clinical practice according to institutional imaging protocols and case-specific assessment by the interpreting radiologist; no predefined allocation criteria were applied. Primary outcomes were intraoperative cutting guide fit and PSI fit, defined as stable anatomical seating without visible gap or rocking and no need for intraoperative modification. The secondary outcome was occlusal outcome (as planned/compromise/reoperated). Radiation exposure during the orthognathic surgical phase was quantified using dose–area product (DAP) and effective dose. Baseline comparability between protocol groups was explored using bivariate analyses and logistic regression. The ULD protocol resulted in a significantly lower effective dose (40.3 µSv) compared with the standard-dose protocol (89.0 µSv, p < 0.001). No significant differences were observed in cutting guide fit (p = 0.450) or PSI fit (p = 0.238). In logistic regression analysis, age was associated with protocol allocation (p = 0.014), whereas sex, diagnosis, and procedure type were not. Thirty-seven of 40 PSIs were clinically acceptable intraoperatively. Both CBCT protocols were clinically adequate for PSI-based orthognathic planning. ULD CBCT provides sufficient image quality and intraoperative usability for VSP in cleft and dentofacial deformity surgery while significantly reducing radiation exposure. These findings support adherence to the ALARA principle in patients requiring repeated imaging.