title: Moderate quality evidence that surgical anchorage more effective than conventional anchorage during orthodontic treatment.
abstract: METHODS
  Cochrane Oral Health Groups Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, key international orthodontic and dental journals and the World Health Organization (WHO) International Clinical Trials Registry Platform.
  
  
  METHODS
  Randomised controlled trials comparing surgical anchorage with conventional anchorage in orthodontic patients. Trials comparing two types of surgical anchorage were also included.
  
  
  METHODS
  Data extraction was performed independently and in duplicate by three review authors and the Cochrane risk of bias tool was used to assess bias. Random-effects meta-analysis was used for more than three studies when pooling of the data was clinically and statistically appropriate. Fixed-effect analysis was undertaken with two or three studies.
  
  
  RESULTS
  Fifteen studies, involving 543 analysed participants, were included. Five ongoing studies were identified. Eight studies were assessed to be at high overall risk of bias, six at unclear risk and one study at low risk of bias. Ten studies (407 randomised and 390 analysed patients) compared surgical anchorage with conventional anchorage for the primary outcome. A random-effects meta-analysis of seven studies for the primary outcome found strong evidence of an effect of surgical anchorage. Compared with conventional anchorage, surgical anchorage was more effective in the reinforcement of anchorage by 1.68 mm (95% CI -2.27 mm to -1.09 mm) (moderate quality evidence). This result should be interpreted with some caution, however, as there was a substantial degree of heterogeneity for this comparison. There was no evidence of a difference in overall duration of treatment between surgical and conventional anchorage (low quality of evidence).Information on patient-reported outcomes such as pain and acceptability was limited and inconclusive. When direct comparisons were made between two types of surgical anchorage, there was a lack of evidence to suggest that any one technique was better than another.
  
  
  CONCLUSIONS
  There is moderate quality evidence that reinforcement of anchorage is more effective with surgical anchorage than conventional anchorage, and that results from mini-screw implants are particularly promising. While surgical anchorage is not associated with the inherent risks and compliance issues related to extra-oral headgear, none of the included studies reported on harms of surgical or conventional anchorage.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Reint Meursinge
authors.initials: RM
authors.lastname: Reynders
authors.affiliation: Department of Oral and Maxillofacial Surgery, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: de Lange
mesh_terms: D003758:Dental Implantation, Endosseous; D005260:Female; D006801:Humans; D008297:Male; D052280:Orthodontic Anchorage Procedures / Q000379:methods*; D014087:Tooth Movement Techniques