Conclusion

Performing an isolated mandibular setback under the SFA induces considerable upper airway constriction, whereas bimaxillary orthognathic surgery significantly preserves airway dimensions. Bimaxillary intervention should therefore be considered a safer surgical indication to proactively mitigate the risk of respiratory impairment, particularly in Class III patients requiring substantial mandibular retropositioning. This study provides new evidence that bimaxillary surgery better preserves airway dimensions under the SFA compared with isolated mandibular setback.