title: Effectiveness of early orthopaedic treatment with headgear: a systematic review and meta-analysis.
abstract: Although the headgear appliance has been used extensively to correct anteroposterior discrepancies, its treatment effects have not yet been adequately assessed in an evidence-based manner.
  
  
  
  Aim of this systematic review was to assess the therapeutic and adverse effects of early headgear treatment from controlled clinical trials on human patients in an evidence-based manner.
  
  
  
  An unrestricted electronic search of six databases from inception to December 2015.
  
  
  
  Randomized and prospective non-randomized controlled trials assessing the effects of headgear treatment on human patients.
  
  
  
  After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of mean differences (MDs) and relative risks (RRs), including their 95% confidence intervals (CIs) were performed, followed by subgroup and sensitivity analyses.
  
  
  
  A total of 18 unique studies with a total of 930 (56% male/44% female) patients were included. Headgear treatment was associated with a posterior translation of the anterior maxilla border in the short term, as seen by the mean annualized change in the SNA angle (MD = -1.63°/year; 95% CI = -2.20 to -1.06°/year; high quality evidence) compared to untreated patients. This effect was independent of the rotation of the palatal plane and the inclination of the upper incisors, while a proportional relationship with the initial discrepancy in SNA was seen. The clinical significance of this improvement diminished in the long term, although only limited evidence existed. Additionally, early headgear treatment might decrease the risk of dental trauma during the following years (RR = 0.34; 95% CI = 0.14 to 0.80; moderate quality evidence). Low quality evidence on the effect of headgear on the rotation of the palatal plane, the nasolabial angle, the occlusal outcome, and signs of temporomandibular disorders precluded robust assessments, due to risk of bias, inconsistency, imprecision, and small-study effects.
  
  
  
  Based on existing trials, headgear is a viable treatment option to modify sagittal growth of the maxilla in the short term in Class II patients with maxillary prognathism.
  
  
  
  PROSPERO (CRD42015029837).
  
  
  
  None.
authors.affiliation: Oral Technology, School of Dentistry, University of Bonn, Bonn, Germany and.
authors.forename: Spyridon N
authors.initials: SN
authors.lastname: Papageorgiou
authors.affiliation: Department of Orthodontics and.
authors.forename: Eric
authors.initials: E
authors.lastname: Kutschera
authors.affiliation: Department of Orthodontics and.
authors.forename: Svenja
authors.initials: S
authors.lastname: Memmert
authors.affiliation: Department of Orthodontics and.
authors.forename: Lina
authors.initials: L
authors.lastname: Gölz
authors.affiliation: Department of Orthodontics and.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jäger
authors.affiliation: Oral Technology, School of Dentistry, University of Bonn, Bonn, Germany and.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bourauel
authors.affiliation: Clinic of Orthodontics and Paediatric Dentistry, Center of Dental Medicine, Faculty of Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Theodore
authors.initials: T
authors.lastname: Eliades
mesh_terms: D019317:Evidence-Based Medicine / Q000379:methods; D005115:Extraoral Traction Appliances / Q000009:adverse effects; D006801:Humans; D007180:Incisor / Q000473:pathology; D008437:Maxilla / Q000254:growth & development / Q000473:pathology; D009971:Orthodontics, Corrective / Q000295:instrumentation / Q000379:methods*; D011378:Prognathism / Q000473:pathology / Q000628:therapy*; D011446:Prospective Studies; D012399:Rotation; D055502:Secondary Prevention / Q000379:methods