Three-dimensional planning accuracy and follow-up of Le Fort I osteotomy in cleft lip/palate patients.

Objectives: Our aim was to determine the accuracy of the three-dimensional (3D) virtual planning and stability of LeFort I osteotomy in cleft lip and/or palate patients (CLP) using a validated 3D method. Materials and methods: Eight patients with a history of cleft lip/palate treated with LeFort I osteotomy for maxillary hypoplasia between January 2016 and April 2020 were included in this retrospective study. Three dimensional virtual planning was performed using Proplan software then transferred to the operation theater via 3D printed occlusal wafers. The accuracy of the 3D planning and the 1-year stability of the maxilla were evaluated by means of a validated semiautomatic stepwise module in Amira software resulting into 3 linear measurements: anterior/posterior, medial/lateral, superior/inferior and 3 rotational measurements: pitch, roll, yaw. Results: The largest mean absolute difference (MAD) for accuracy assessment was found in the A/P direction (2.75mm +/- 2.25 mm) and in pitch (3.23 degrees +/- 2.11 degrees). For A/P translation, an error of >2 mm was observed in 5 (62.5%), for S/I translation an error of >2 mm was observed in 4(50.0%) of the 8 patients, whereas for pitch 3 patients(37,5%) showed an error >4 degrees At one year follow-up, the largest linear and rotational MAD was found in the A/P direction (1.20mm +/- 0.92 mm) and in pitch (3.31 degrees +/- 2.31 degrees). Conclusions: Findings of this study show that 3D virtual computer-assisted orthognathic surgery enables an accurate repositioning of the hypoplastic maxilla in CLP patients. However, A/P translations and pitch rotations remain challenging to achieve during surgery. These movements were also found to be least stable at one year follow-up. (c) 2023 Elsevier Masson SAS. All rights reserved.