title: Early treatment with a maxillary lip bumper-bite plateau combination.
abstract: OBJECTIVE
  To evaluate the intra-arch displacements of the molars and the change in molar relationship following the use of a maxillary lip bumper combined with a bite plate.
  
  
  METHODS
  The material comprised study casts taken before and after the treatment of 40 consecutive patients with mixed dentition. The sagittal and transversal displacements were evaluated by a three-dimensional digitizer using the palatal rugae as an indirect fixed reference. The displacements were expressed as translation mesiodistally and buccolingually and rotation around the long axis and tipping mesiodistally. The change in molar relationship was measured to the nearest millimeter at the level of the occlusal plane.
  
  
  RESULTS
  The tooth movements were predominantly of distal rotation (mean, 9.7 degrees ; range, 6.5 degrees to 26 degrees ) and distal tipping (mean, 5 degrees ; range, 5.8 degrees to 18 degrees ). The distal displacement was a modest mean (mean, 0.3 mm; SD, 1.6 mm) and more pronounced to the buccal (mean 1.6 mm; SD, 1.5 mm). The molar relationship improved in all but four sites, and a full Class I was obtained in 65 of 80 sites.
  
  
  CONCLUSIONS
  The early treatment with the lip bumper and bite plate can be recommended from a cost-benefit point of view.
authors.affiliation: Department of Orthodontics, Tufts University, Boston, MA, USA.
authors.forename: Marcel
authors.initials: M
authors.lastname: Korn
authors.forename: Birte
authors.initials: B
authors.lastname: Melsen
mesh_terms: D002508:Cephalometry / Q000379:methods; D002648:Child; D003724:Dental Arch / Q000473:pathology; D003818:Dentition, Mixed; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008437:Maxilla / Q000473:pathology*; D008963:Molar / Q000473:pathology; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D009969:Orthodontic Wires; D010159:Palate / Q000473:pathology; D012399:Rotation; D014087:Tooth Movement Techniques / Q000295:instrumentation