title: Dentoskeletal effects produced by a Jasper Jumper with an anterior bite plane.
abstract: 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.
  
  
  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.
authors.affiliation: a  Private Practice Orthodontist, Prato, Italy.
authors.forename: Turi
authors.initials: T
authors.lastname: Bassarelli
authors.affiliation: b  Assistant Professor, Department of Surgery and Translational Medicine, Tuscan Dental School, The University of Florence, Florence, Italy, and Thomas M. Graber Visiting Scholar, Department of Orthodontics and Pediatric Dentistry, School of Dentistry, The University of Michigan, Ann Arbor, Mich.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Franchi
authors.affiliation: c  Associate Professor, Department of Surgery and Translational Medicine, Tuscan Dental School, The University of Florence, Florence, Italy.
authors.forename: Efisio
authors.initials: E
authors.lastname: Defraia
authors.affiliation: d  Professor Emeritus, University of Aarhus, Aarhus, Denmark.
authors.forename: Birte
authors.initials: B
authors.lastname: Melsen
mesh_terms: D000202:Activator Appliances; D000293:Adolescent; D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008334:Mandible; D017289:Orthodontic Appliances, Functional; D057887:Overbite; D012189:Retrospective Studies
keywords: Bite plane; Class II malocclusion; Jasper Jumper