Field of View Optimization in Cone-Beam Computed Tomography for Bilateral Alveolar Clefts Before and After Bone Grafting

ObjectiveTo investigate in field of view (FOV) reduction in cone-beam computed tomography (CBCT) examinations of patients with bilateral alveolar clefts for dose reduction and potential missed information of dental anomalies.DesignRetrospective cohort study.SettingDepartment of Oral and Maxillofacial Radiology, Falu lasarett, Sweden.Patients36 patients (24 males and 12 females) with bilateral alveolar clefts, with 70 CBCT examinations performed before and after alveolar bone grafting exposed between 2016 and 2020. All examinations had a FOV of 80 × 50 mm.InterventionsTwo reduced-FOV protocols were measured: a larger preoperative protocol including upper canines and the anterior maxilla, and a smaller postoperative protocol depicting the cleft areas.Main Outcome MeasureSuggested FOV dimensions for clinical use before and after bone graft.ResultsThe suggested preoperative protocol (65 × 45 mm) resulted in an estimated 27% reduction in radiation dose, whereas the postoperative protocol (35 × 35 mm) achieved a 62% reduction compared with the original FOV. Incidental findings were detected in 80% of the suggested preoperative protocol and in none of the suggested postoperative protocols.ConclusionThe suggested FOV reduction protocols for CBCT may substantially reduce radiation exposure while maintaining essential information. A preoperative FOV of 65 × 45 mm and a postoperative FOV of 35 × 35 mm are suggested for CBCT of bilateral alveolar clefts.