A cephalometric study of Class II Division 1 malocclusions treated with the Jasper Jumper appliance

This lateral cephalometric study investigated the dental and skeletal effec ts of the Jasper Jumper appliance used in the correction of Class II Divisi on 1 malocclusions. A sample of 36 growing patients treated with the Jasper Jumper appliance was divided into two groups: (1) 24 patients with records obtained at the start and completion of orthodontic treatment, and (2) 12 patients with records available at the beginning and end of the Jumper phas e of treatment. Treatment effects were determined by statistical comparison s of cephalometric changes in the patients relative to age-adjusted cephalo metric standards, and from structural superimpositions. While the Jumpers w ere in place, maxillary incisors were retroclined and the molars were moved distally, tipped back, and intruded. The mandibular incisors were procline d and intruded, while the molars were translated mesially, tipped forward, and extruded. Skeletal measures showed reduced forward maxillary displaceme nt and no significant alteration of horizontal mandibular growth. During or thodontic finishing, molar tipping and maxillary incisor retroclination wer e corrected, although the mandibular incisors remained proclined. In summar y, this study found that the Jasper Jumper appliance corrected Class II dis crepancies largely through maxillary and mandibular dentoalveolar effects a nd, to a limited extent, by restraint of forward maxillary growth.