Edition V14N06 | Year 2009 | Editorial Article | Pages 82 to 96
Introduction: The Jasper Jumper is a fixed functional appliance which keeps the mandible in a protruded position by applying continuous light forces. Even though previous studies have revealed the clinical outcome of the appliance, there is still some debate about how much correction is achieved by skeletal changes vs. dentoalveolar changes. Objective: The objective of this study was to evaluate the skeletal and dentoalveolar effects of the treatment of Class II malocclusion with the Jasper Jumper appliance associated with fixed orthodontic appliances, compared to an untreated control group. Material and Methods: The sample comprised 47 subjects, divided into two groups: Group 1, with 25 patients at a mean initial age of 12.72 years, treated with the Jasper Jumper appliance for a mean period of 2.15 years; and Group 2 (Control), included 22 subjects at a mean initial age of 12.67 years, who were not submitted to any type of orthodontic treatment and presenting Class II malocclusion, observed by a mean period of 2.12 years. Lateral cephalograms before and after orthodontic treatment for group 1 and during the observational period for group 2 were evaluated. Initial and final dentoskeletal cephalometric variables and changes with treatment were compared between the groups by independent t tests. Results: When compared to the control group, the Jasper Jumper group presented greater restriction of anterior displacement of the maxilla and a greater maxillary retrusion, improvement of maxillomandibular relationship, reduction of facial convexity, greater protrusion and intrusion of mandibular incisors and a greater extrusion of mandibular molars, besides a greater reduction of overjet and overbite and improvement of molar relationship. Conclusion: The correction of the Class II in the group treated with the Jasper Jumper and fixed appliances was mainly due to restriction of maxillary growth, protrusion and intrusion of mandibular incisors and extrusion of mandibular molars.