title: Early treatment of posterior crossbite--a randomised clinical trial.
abstract: BACKGROUND
  The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis.
  
  
  METHODS
  This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the 'Digimodel' software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded.
  
  
  RESULTS
  Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite.
  
  
  CONCLUSIONS
  Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced.
  
  
  BACKGROUND
  Registration trial DRKS00003497 on DRKS.
authors: Poliklinik für Kieferorthopädie, Universität Münster, Waldeyerstr 30, 48149 Münster, Germany. lippold@uni-muenster.de
authors: Carsten
authors: C
authors: Lippold
authors: Thomas
authors: T
authors: Stamm
authors: Ulrich
authors: U
authors: Meyer
authors: András
authors: A
authors: Végh
authors: Tatjana
authors: T
authors: Moiseenko
authors: Gholamreza
authors: G
authors: Danesh
mesh_terms: D002648:Child; D002675:Child, Preschool; D003766:Dental Occlusion; D003818:Dentition, Mixed; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008437:Maxilla / Q000254:growth & development*; D010155:Palatal Expansion Technique / Q000295:instrumentation*; D011379:Prognosis; D014094:Tooth, Deciduous