The purpose o1 this study is to evaluate the dental and soft tissue changes in patients treated with the Jasper Jumper appliance which was filled with sectional arches. The study sample consisted of 30 subjects (15 treated, 15 untreated) with skeletal and dental Class II malocclusion. Our study was carried out on 60 lateral cephalometric films which were taken before placement and after removal of the Jasper Jumper appliance in the treatment group, and at inital and six months follow-up in the control group. The patient selection criteria were as follows skeletal and dental Class II malocclusion characterized by retrognathic mandible, normal or low angle vertical growth pattern, and post-peak growth period. The statistical assessment of the data suggested the following conclusions. The mandibular incisors were protructed and intructed while the maxillary incisors were retructed and extructed. The occlusal plane was rotated in clockwise direction as a result of dentoalveoler changes. Overbite and overjet were reduced in all patients. Soft tissue profiile improved significantly. As a result of the overjet reductiuon due to the retrusion of the upper incisors, the upper lip moved back and the lower lip no longer captured at the back of the upper incisors. Moreover, the lower incisors which are proclined supported the lower lip. Lip strength decreased favorably as a result of the upper incisors retrusion. The results of this study revealed that in late-adolescent patients Jasper Jumper appliance corrected Class II discrepancies mosbly through dentoalveolar changes. It is suggested that this treatment method could be an alternative to orthognathic surgery in borderline Class II cases.

Keywords: Jasper Jumper, functional therapy, skeletal Class II malocclusion, incisor inclination, dentofacial orthopedics, facial profile