Three-Dimensional Analysis of Airway Change After LeFort III Midface Advancement With Distraction.

INTRODUCTION: LeFort III midface advancement using the distraction technique became the standard method for the correction of various craniofacial syndromes accompanied by the midface retrusion. Midface hypoplasia is known to be related to the imbalance in facial aesthetics, malocclusion, and the airway problem. This study aimed to evaluate the change in airway volume after performing a LeFort III midface advancement with the distraction techniques.

PATIENTS AND METHODS: Between April 2008 and February 2013, 7 patients aged 5 to 7 years underwent standard LeFort III osteotomy, followed by distraction with a rigid external distractor with or without internal distractor. The degree of advancement of the midface and the airway volume were evaluated with 3-dimensional computed tomography scans and the 3-dimensional software.

RESULTS: The average latent period was 3.57 days. The average manual distraction distance was 17.55 mm for 3.82 weeks. The consolidation period ranged from 3 to 7 months. Changes between the preoperative and postoperative airway volumes were remarkable. The average preoperative postpharyngeal airway volume was 5649.33 mm compared with an average postoperative airway volume of 7403.44 mm. Therefore, the average postpharyngeal airway space increased by a remarkable 32.78%.

CONCLUSIONS: This investigation revealed that the LeFort III midface advancement using distraction could increase postpharyngeal airway space by approximately 33% when the midface is advanced by approximately 18 mm. This method could be used as a future reference for LeFort III midface advancement with distraction.