Splintless surgery using patient-specific osteosynthesis in Le Fort I osteotomies: a randomized controlled multi centre trial

The accuracy of orthognathic surgery has improved with three-dimensional virtual planning. The translation of the planning to the surgical result is reported to vary by >2 mm. The aim of this randomized controlled multi-centre trial was to determine whether the use of splintless patient-specific osteosynthesis can improve the accuracy of maxillary translation. Patients requiring a Le Fort I osteotomy were included in the trial. The intervention group was treated using patient-specific osteosynthesis and the control group with conventional osteosynthesis and splint-based positioning. Fifty-eight patients completed the study protocol, 27 in the patient-specific osteosynthesis group and 31 in the control group. The per protocol median anteroposterior deviation was found to be 1.05 mm (interquartile range (IQR) 0.45-2.72 mm) in the patient-specific osteosynthesis group and 1.74 mm (IQR 1.02-3.02 mm) in the control group. The cranial-caudal deviation was 0.87 mm (IQR 0.49-1.44 mm) and 0.98 mm (IQR 0.28-2.10 mm), respectively, whereas the left-right translation deviation was 0.46 mm (IQR 0.19-0.96 mm) in the patient-specific osteosynthesis group and 1.07 mm (IQR 0.62-1.55 mm) in the control group. The splintless patient-specific osteosynthesis method improves the accuracy of maxillary translations in orthognathic surgery and is clinically relevant for planned anteroposterior translations of more than 3.70 mm.