Correlation between maxillary movement and changes in nasolabial and nasofacial angles after Le Fort I osteotomy

Nasal aesthetic changes are a key concern in orthognathic surgery. This retrospective cohort study investigated whether the direction and magnitude of maxillary movement independently affect postoperative nasolabial angle (NLA) and nasofacial angle (NFA) following Le Fort I osteotomy in bimaxillary surgery. Forty-four patients (10 men, 34 women; median age 24 years) treated at a single institution were analyzed using standardized lateral cephalograms obtained preoperatively and at 1 week and 12 months postoperatively. Horizontal (anteroposterior) and vertical (superoinferior) maxillary displacements were derived from three-dimensional surgical planning and validated by cephalometric superimposition. Changes in NLA and NFA were assessed using Pearson correlation and multiple linear regression analyses, including change in sella-nasion-B point (SNB) angle as a confounder. Horizontal advancement was significantly correlated with NLA (r = 0.32, P = 0.034) and NFA (r = 0.68, P < 0.001), whereas vertical movement showed no significant correlation with NLA and a modest negative correlation with NFA (r = -0.43, P = 0.004). Multiple regression analysis showed that horizontal advancement independently predicted increased NFA (unstandardized coefficient = 0.80, P < 0.001), whereas the NLA model was not statistically significant (R² = 0.13, P = 0.114). Horizontal maxillary advancement demonstrated a relatively predictable relationship with NFA, whereas NLA changes were more variable and less reliably predicted by skeletal movement alone. NFA may therefore be a more robust parameter for preoperative prediction, patient counseling, and refinement of digital surgical simulations.