Uprighting the mandibular molars stimulates mandibular growth during treatment of class II malocclusion

We hypothesized that uprighting of the mandibular molars creates a counter-clockwise rotation of the mandible and stimulates mandibular forward growth during the treatment of a Class II malocclusion. This investigation used 33 longitudinal lateral cephalometric radiographs of Class II, Division 1 female patients. All cases were treated with non-extraction. Treatment was started in early adolescence with .018 slot edgewise Alexander appliances. High-pull head-gear and Class II elastics were used. Seventeen cases that showed more than 5 degrees of uprighting of the mandibular first molars were selected as the uprighted group. Cases that showed less than 5 degrees of uprighting of the mandibular first molars were selected as the non-uprighted group. There was a significant correlation coefficient between the uprighted degree of the mandibular first molars and the degree of clockwise rotation of the mandibular plane to FH.