Evaluation of profile esthetic change with mandibular advancement surgery.

Our purpose was to investigate the impact of mandibular advancement surgery on profile esthetics and to attempt to define guidelines that could be of value to the clinician in predicting profile esthetic change. The sample consisted of 34 patients who had been treated with a combination of orthodontics and mandibular advancement surgery without genioplasty. Initial (pretreatment) and final (posttreatment) cephalometric radiographs of each patient were used to produce silhouette images and to quantify skeletal changes that occurred with surgery. The images were displayed randomly to lay persons and orthodontic residents who were asked to score the esthetics of each profile. On average, after mandibular advancement surgery, B point moved forward 5.0 mm (SD = 2.6 mm) and downward 4.7 mm (SD = 3.1 mm), and the ANB angle decreased 3.0 degrees (SD = 1.6 degrees ) Graphical analysis and results of paired t tests revealed that for patients with an initial ANB angle >/= 6 degrees, a consistent improvement in profile esthetics was seen following surgery (P </=.001). This represented, on average, about a 45% improvement in esthetics. For patients with an initial ANB angle < 6 degrees, an improvement in profile esthetics after surgery was seen about half the time but poorer esthetics were equally likely. These results underscore the importance of using the ANB angle as a skeletal guideline when deciding whether to treat patients with mandibular advancement surgery. If improved profile esthetics are a desired outcome, an initial ANB angle of at least 6 degrees is recommended.