Correlation analysis of eye and lip canting correction after bimaxillary orthognathic surgery and orthodontic treatment.

BACKGROUND

Facial asymmetry is a frequent indication for orthognathic surgery. Vertical discrepancies such as eye and lip canting strongly influence perceived facial balance. While orthognathic surgery effectively repositions skeletal structures, the extent of soft tissue canting correction remains uncertain.

METHODS

This retrospective study included 25 patients who underwent bimaxillary orthognathic surgery followed by orthodontic treatment between 2017 and 2023. Patients were classified into three groups: eye + lip canting (Group A, n = 10), Eye canting, lip canting, soft tissue chin deviation, and commissure height difference were measured using standardized frontal photographs and cephalometric radiographs at three time points: preoperative (T0), postoperative (T1), and post-debonding (T2). One-way ANOVA and Tukey's post hoc test were used.

RESULTS

Orthognathic surgery significantly improved both eye and lip canting (P < 0.05). Lip canting showed greater responsiveness than eye canting. Soft tissue chin deviation and commissure height difference also demonstrated significant postoperative improvements that were maintained through the debonding stage. Minimal or no further changes occurred during orthodontic treatment. Group A demonstrated the greatest overall improvement.

CONCLUSION

Bimaxillary orthognathic surgery effectively improves soft tissue canting, particularly of the in the lower face. Most correction occurs during the surgical phase, while orthodontics contributes minimally.