The impact of clockwise and counterclockwise Le Fort I movements combined with bilateral sagittal split osteotomy on nasal morphology

PURPOSE: Orthognathic surgery is known to induce measurable alterations in nasal morphology. This study retrospectively assessed pre- and postoperative three-dimensional (3D) surface models (SMs) to evaluate nasal soft-tissue changes associated with clockwise (CW) and counterclockwise (CCW) Le Fort I movements combined with bilateral sagittal split osteotomy (BSSO). METHODS: Fifty-six patients (23 CW, 33 CCW) who underwent Le Fort I osteotomy with BSSO between January 2016 and February 2020 were included. 3D SMs were obtained 1 day preoperatively and 6 weeks postoperatively using the Vectra M5 stereophotogrammetry system (Canfield Scientific, USA). Seventeen anthropometric nasal parameters were measured with OnyxCeph3 (Image Instruments, Germany). RESULTS: In the overall cohort, 8 of 17 nasal parameters showed significant postoperative changes. Most notably, transverse nasal dimensions increased, while nasal height and nasal dorsum length decreased. Subgroup analyses revealed that, after Holm-Bonferroni adjustment, 2 parameters remained significant in the CW group and 6 in the CCW group. However, direct between-group comparisons revealed no significant differences in the magnitude of postoperative changes. CONCLUSION: Le Fort I osteotomy combined with BSSO consistently alters nasal morphology, particularly by widening the alar and subalare regions and reducing nasal height. While both CW and CCW rotations produced measurable anthropometric changes, direct between-group comparisons showed no significant differences in the magnitude of postoperative changes.