Dentoskeletal effects produced by a Jasper Jumper with an anterior bite plane.

OBJECTIVE: The aim of this retrospective study was to evaluate the dentoskeletal effects produced by a modified Jasper Jumper with an anterior bite plane for the correction of Class II division 1 malocclusion. MATERIALS AND METHODS: A sample of 32 growing patients (mean age = 11.9 +/- 1.4 years) with Class II division 1 malocclusion and increased overbite were treated with a modified Jasper Jumper (JJ) and anterior bite plane protocol and compared with a matched control group of 30 subjects with untreated Class II malocclusion (mean age 12.2 +/- 0.8 years). Lateral cephalograms were taken before treatment (T1) and at the end of comprehensive treatment (T2). Mean treatment duration was 2.1 +/- 0.4 years. The T1-T2 changes in the two groups were compared with Student's t-tests for independent samples. RESULTS: The JJ group was successfully treated to a Class I occlusal relationship with a significant reduction in overjet (-3.9 mm, P < .001) and overbite (-3.1 mm, P < .001). The JJ group exhibited a significant increase in mandibular length and a significant improvement in maxillomandibular sagittal skeletal relationships. The lower incisors were significantly proclined, while the lower first molars demonstrated significant movement in a mesial direction. CONCLUSIONS: Use of a modified JJ appliance and anterior bite plane is an effective protocol for the treatment of Class II malocclusion with increased overbite and greater skeletal (75%) than dentoalveolar (25%) effects mainly at the mandibular level.