ABSTRACT
The aim of this study was to evaluate the effects of Jasper Jumper appliance in patients with skeletal Class II Division I malocclusion. The study group consisted of 14 subjects with a mean age of 14.0±1.7 years. Lateral cephalograms and study models of all the patients were obtained after the leveling phase and at the end of Jasper Jumper use. Jasper Jumper appliance did not have a retrusive effect on the maxilla, however, it stimulated mandibular growth. The increases in the SNB angle, Co-Gn distance, anterior and posterior face heights and the decrease in the ANB angle were significant skeletal changes. Maxillary incisors were intruded and retruded while lower incisors were extruded and protruded. Maxillary first molars were also intruded with significant distal drift. On the contrary, mandibular first molars showed extrusion and drifted mesially. Study model analysis sowed that expansion occurred both in the maxillary and mandibular dental arches during Jasper Jumper use.