Cephalometric evaluation of pharyngeal airway space changes in class III patients undergoing orthognathic surgery.

PURPOSE: The purpose of this study is to retrospectively evaluate pharyngeal airway space (PAS) changes in patients with skeletal Class III deformity who received different skeletal repositioning.

MATERIALS AND METHODS: A cephalometric evaluation of 45 patients with skeletal Class III deformity was performed. The subjects were divided into 3 groups: group 1 underwent bimaxillary surgery (23 patients), group 2 underwent maxillary advancement surgery (15 patients), and group 3 underwent mandibular setback surgery (7 patients). The PAS was evaluated with the cephalometric analysis of Arnett-Gunson FAB surgery and Dolphin Imaging 11 (Dolphin Imaging and Management Solutions, Chatsworth, CA) preoperatively, 1 week postoperatively, and at least 1 year postoperatively.

RESULTS: In patients who received bimaxillary surgery, changes in the PAS in the immediate postoperative period were observed. However, long-term measurements at the oropharyngeal level returned to preoperative values. After maxillary advancement, there was an increase in the oropharynx and nasopharynx that remained long-term. In patients who underwent mandibular setback, no changes in the PAS were observed.

CONCLUSION: In patients who underwent bimaxillary surgery, upper jaw advancement compensated for changes of the PAS brought about by the mandibular setback. Patients who received mandibular setback surgery showed no changes in the PAS, and those who underwent maxillary advancement showed a significant increase of the PAS and that remained stable during the evaluation period. As a consequence, maxillary advancement seems to be the most stable surgical movement in relation to airway dimensional gains.