INTRODUCTION The objective of this controlled clinical study was to compare the dentoskeletal effects of the Jasper jumper with those of cervical headgear, when both are used with edgewise appliances to correct Class II Division 1 malocclusion.
Lateral cephalograms of 75 patients were divided into 3 groups of 25. The control group included untreated Class II children with an initial mean age of 11.82 years (range, 9.35-14.84 years); they were followed without treatment for a mean period of 1.95 years (range, 0.90-3.95 years). The Jasper jumper group had an initial mean age of 11.86 years (range, 9.45-14.94 years); they were treated for a mean period of 1.96 years (range, 0.93-3.98 years). The cervical headgear group had an initial mean age of 12.29 years (range, 9.95-15.24 years); they were treated for an average of 1.88 years (range, 0.95-3.95 years). Comparison of the initial measurements showed that the 3 groups were similar at pretreatment, thus allowing direct comparisons. Analysis of variance (ANOVA) and the Tukey test were applied for comparison of the groups.
Different appliances yielded specific effects on several components (skeletal and dentoalveolar) evaluated. Anterior maxillary growth was significantly restricted by the cervical headgear. Mandibular growth was similar in all 3 groups, although it was slightly greater in the Jasper jumper group. The experimental groups had similar improvements in maxillomandibular relationshipd. The pattern of craniofacial growth was not significantly different between groups. The most significant effect on the maxillary dentoalveolar component was retrusion of the maxillary incisors by the cervical headgear. The effects observed for the Jasper jumper group were primarily related to the mandibular dentoalveolar component, including labial tipping and protrusion of the mandibular incisors, and mesial movement and extrusion of the mandibular molars compared with the control group.
The headgear appliance corrected the Class II malocclusion mostly by anterior maxillary restriction and maxillary dentoalveolar effects. Correction of the Class II malocclusion with the Jasper jumper appliance was largely due to mandibular dentoalveolar effects rather than skeletal effects.