Introduction
The aim of this study was to compare 3D airway changes after 2-jaw orthognathic surgery(maxilla Le-Fort I advancement and mandible BSSO setback) on skeletal Class III malocclusion patient using computed tomography.

Diagnosis
Class III malocclusion

Treatment overview
An 18-year-old female came with the concern about protrusive chin and anterior crossbite with inability to incise. Clinical examination revealed Class III malocclusion with overjet -2.5mm. Cephalometric analysis showed SNA 78^o, SNB 81^o and ANB -3^o, which was diagnosed as skeletal class III ~~base~~ malocclusion. The patient was therefore treated with full mouth orthodontic appliance combined OGS for maxilla advancement and mandible setback. After 16-months treatment, the malocclusion was corrected with solid interdigitation. Pre- and post-surgery computed tomography were taken to compared velopharyngeal and oropharyngeal airway. The total 3D airway volume was enlarged.

Conclusion
This case report found that orthognathic surgery with maxilla advancement and mandible setback on skeletal Class III patient would not lead to the narrowing of airway. On the contrary, proper surgical plan will improve the airway after surgery.

摘要