Changes in head posture, hyoid bone position and airway dimensions after orthognatic surgery

Abstract

Mandibular/bimaxillary advancement surgery is described as a potential means of increasing the oropharyngeal airspace , provided a significant improvement in breathing capacity. Aim: To evaluate postural changes suffered in the positioning of the head and the hyoid bone, dentofacial deformity patients undergoing orthognathic surgery with consequent dimensional changes of oropharyngeal airspace. Methods: We evaluated the archived records of patients with postoperative 6 months minimum, being used as criteria for selecting individuals with dental class II malocclusion and facial Pattern II, jaw or maxilomandibular deficiency, patients undergoing orthodontic-surgical treatment through mandibular advancement or of both bony bases, associated or not to genioplastia. Twenty-eight patients were part of the sample and were evaluated by means of lateral radiographs in lateral standard digitized, in three distinct periods: pre-operative, immediate postoperative period and late postoperative period (minimum 6 months). 12 linear measures and two angular cephalometric analysis were used in this research. Results: With the surgery, there was an average of mandibular advancement 6, 76 mm, while remaining stable in the long-term follow-up period; the hyoid bone moved onward and upward, extending your movement in the post-operative. The cervical region presented minimal movement of the head extension in the immediate post operative with almost total returns the position of the head in the post-operative. The surgical movement of oropharyngeal air space was in the same direction of the mandibular movement, but to a lesser extent (1,88 -2,76 mm). In the post-operative period was a late partial reduction of the diameter of the air space between 34-56% of gain, representing an apparent accommodation of this anatomical region soft tissue. Conclusion: Orthognathic surgery of mandibular advancement or bimaxillary promotes significant changes in aesthetics, in the position of the hyoid bone and upper airway dimensions, getting better quality of life to these patients.