Patients with skeletal Class III deformities may present with regional midfacial deficiency. This study compared the 12-month midfacial soft-tissue changes following conventional and high Le Fort I osteotomies.

This prospective comparative cohort study included 20 patients undergoing bimaxillary orthognathic surgery with conventional (n = 10) or high (n = 10) Le Fort I osteotomies. The osteotomy design was selected according to the preoperative midfacial projection line. Three-dimensional cone-beam computed tomography was used to measure changes in the paranasal, anterior cheek, and lateral cheek coordinates from baseline to 12 months. Between-group differences were assessed using Welch’s test, with false discovery rate adjustment for multiple comparisons.

Age, sex distribution, maxillary advancement, and maxillary impaction were comparable between the groups, whereas the high Le Fort I group had a greater baseline midfacial deficiency. Unadjusted analyses demonstrated greater paranasal and anterior cheek changes in the high Le Fort I group, with no significant lateral cheek differences. After adjusting for age, sex, maxillary advancement, and maxillary impaction, the associations remained significant for all paranasal coordinates and the anterior cheek X and Y coordinates after FDR correction; the anterior cheek Z association did not remain significant after FDR correction.

In this anatomy-guided prospective cohort, high Le Fort I osteotomy was associated with greater 12-month paranasal and anterior cheek soft-tissue changes than conventional Le Fort I osteotomy, whereas lateral cheek changes were comparable. Because osteotomy selection was based on preoperative midfacial anatomy, these findings represent associations within this cohort and should not be interpreted as evidence of an independent causal effect of osteotomy height on the outcome.