Treatment of Class II malocclusions with the Jasper Jumper appliance--a preliminary report.

The effect of the Jasper Jumper appliance (American Orthodontics, Sheboygan, Wis.) on the dentofacial complex was studied in 17 consecutive growing patients who had Class II, Division 1 malocclusions. Lateral cephalograms taken before treatment and immediately after removal of the Jumpers were analyzed according to the method of Pancherz. The following results were found: (1) Class I occlusal relationships were achieved in all patients in an average treatment time of 6 months. (2) The correction of the Class II malocclusion was a result of skeletal (40%) and dental (60%) changes. (3) Skeletal Class II correction was predominantly restricted to the mandible. (4) The dentoalveolar part of total molar relationship correction took place to the same extent in both jaws, whereas in overjet correction the maxillary dental changes outweighed the mandibular changes by far. (5) When compared with normal growth changes (Bolton standards), treatment with Jasper Jumpers distalizes the upper dentition and moves the lower teeth mesially. Mandibular growth seems to be increased to some extent. It was concluded that treatment with the Jasper Jumper appliance presents an effective method to correct Class II malocclusion in growing patients.