Abstract:
Abstract:
Objective: To clarify the effects of setback surgery and advance surgery for jaw deformity on hyoid bone position, pharynx airway, and swallowing function.

Methods: The subject were 22 patients with dentofacial deformities who underwent mandibular setback surgery (14 patients) or advance surgery (8 patients). Morphological changes were studied on cephalograms, and swallowing function was evaluated by videofluorography before surgery, after surgery, and 1 month after surgery.

Results: The angle of the SNB was smaller in the advance group than in the setback group at any period compared. The oropharyngeal spaces were significantly shorter in the advance group than in the setback group before surgery. After surgery and 1 month after surgery, there were no significant differences in the oropharyngeal spaces between the setback group and the advance group. The swallowing time in the oral phase was longer after surgery than before surgery in the videofuluorography. In the advance group, barium inflow into pharynx before swallowing and stasis in epiglottic valleculae and the oral cavity after swallowing were assessed after surgery.

Conclusions: In the setback and advance group, the oral phase of the swallowing function recovered 1 month after orthognathic surgery. However, lingual movement was insufficient, and care had to be exercised with regard to aspiration immediately after advance surgery.

Key words: orthognathic surgery, swallowing function, aspiration, suprahyoid muscles.