title: Clinical profile of rapid maxillary expansion--outcome of a national inquiry.
abstract: BACKGROUND
  Rapid maxillary expansion (RME) is a therapeutic orthodontic option with a long history, and there are many reports in the literature reporting widely divergent results concerning the appliance efficacy and many different treatment protocols. We aimed to evaluate the treatment protocols and clinical experiences with RME via a national inquiry of orthodontists to identify the status quo of RME in clinical daily routine.
  
  
  METHODS
  Within the framework of an anonymous questionnaire, 2003 orthodontists and members of the German Orthodontic Society (DGKFO) were asked to report on their clinical experiences with RME. The standardized questionnaire covered clinical indications, dentition period at the time of insertion, mode of activation, retention time, observed side effects, and the reasons for requiring surgical assistance.
  
  
  RESULTS
  The data from 487 questionnaires could be evaluated. The only indication for RME named by a large majority of responders was transversal maxillary deficiency. The average extent of the transversal deficiency amounted to 5.29 +/- 2.25 mm (median 5 mm). Most orthodontists (87.7%) employed RME in the permanent dentition of adolescents; it was significantly less frequently applied in the primary dentition or adults. Answers regarding the mode of activation varied greatly. The most frequent mode of activation was "1-2 activations a day" independent of the dentition period. 64.5% of the orthodontists reported buccal tipping of the anchorage teeth. No correlation was detected between mode of activation, time of insertion and observed side effects. 60% of the orthodontists reported a retention period of between 3 and 6 months (median 4.5 months). With an average age of 19.28 years, 79.3% assessed chronological age as a limiting factor for conventional RME. It was not possible to identify a homogeneous diagnostic procedure for the indication of surgical assistance.
  
  
  CONCLUSIONS
  Although RME has a long clinical history, no standardized treatment protocols exist. Randomized clinical trials are necessary to make clear-cut clinical recommendations on the use of RME, as required by the tenets of evidence-based medicine and quality assurance.
authors.affiliation: Department of Orthodontics, University of Hamburg, Martinistrasse 52, 20246 Hamburg, Germany. korbmacher@uke.uni-hamburg.de
authors.forename: Heike
authors.initials: H
authors.lastname: Korbmacher
authors.forename: Lothar
authors.initials: L
authors.lastname: Huck
authors.forename: Till
authors.initials: T
authors.lastname: Merkle
authors.forename: Bärbel
authors.initials: B
authors.lastname: Kahl-Nieke
mesh_terms: D005858:Germany / Q000453:epidemiology; D006801:Humans; D009971:Orthodontics, Corrective / Q000379:methods / Q000706:statistics & numerical data; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010155:Palatal Expansion Technique / Q000706:statistics & numerical data*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome