Surgical versus orthodontic correction of skeletal Class II malocclusion in adolescents: effects and indications.

Abstract

To clarify the effects of orthodontic versus surgical treatment and to distinguish more clearly those Class II patients who can be treated successfully with orthodontics alone, we compared three groups of adolescents: forty patients treated successfully with orthognathic surgery, 40 patients treated successfully with orthodontics alone, and 21 patients whose orthodontic treatment was judged to be unsuccessful. Successful surgical treatment was accomplished largely by bringing the mandible forward, but this involved vertically repositioning the maxilla, alone or in combination with advancing the mandible, in 40% of the patients. Successful orthodontic treatment resulted from a combination of retraction of the maxillary incisors and protraction of the mandibular incisors; most of the successfully treated group also had significant vertical growth, and 40% had greater than 2 mm anteroposterior growth. The unsuccessfully treated orthodontic patients initially had greater overjet, more severe mandibular deficiency, and greater anterior facial height than those treated successfully; they also had less retraction of the maxillary incisors and less growth during treatment. In Class II adolescents beyond the growth spurt, surgery is likely to be needed for successful correction of the malocclusion if the overjet is greater than 10 mm, especially if the distance from pogonion to nasion perpendicular is 18 mm or more, mandibular body length is less than 70 mm, or facial height is greater than 125 mm.