[Skeletal and dental changes during the use of the bite-jumping plate. A cephalometric comparison with an untreated Class-II group].

In this study 95 patients with a malocclusion type Angle class II were treated with a bite jumping appliance and the results achieved were compared with untreated class II patients. A clear improvement in the skeletal and dental relationships was observed. Significant changes were achieved yearly in the following: 1. the angle SNA was reduced (0.82 degrees), 2. the angle SNB was increased (0.57 degrees), 3. the angle ANB was reduced (1.39 degrees). All 3 of these variables are significant. Other skeletal variables, most notably the incline of the maxilla to the line NS, were not influenced nor was the relation of posterior facial height to anterior facial height. The mandibular incisors did not exhibit increased protrusion relative to the mandibular plane. Only the angle of the mandibular incisor to NB was changed by the total protrusion of the mandible. The maxillary incisors in these cases manifested obvious lingual tipping. For this reason the orthodontist must weigh carefully on an individual patient basis, whether the use of adjunctive torque springs is required and necessary.