title: Effectiveness of maxillary protraction using facemask with or without maxillary expansion: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Class III therapy using a face mask is a common approach for treatment of a deficient maxilla and reverse overbite. Usually, maxillary protraction is combined with transverse palatal expansion using intraoral appliances. The purpose of this study was to systematically review the effectiveness of face mask therapy in combination with concepts of palatal expansion and compression.
  
  
  METHODS
  A systematic review and meta-analysis were performed to identify studies that address class III treatment using a face mask. The search was carried out using common electronic databases as well as hand search. Both screening and study eligibility analysis were performed with consideration of PRISMA and Cochrane Guidelines for systematic reviews. Several terms describing class III face mask treatment were searched. Particular attention was paid to new strategies of enhancing maxillary protraction.
  
  
  RESULTS
  The initial search identified 2048 studies. After a thorough selection process, a total of 22 articles met the inclusion criteria. After assessment of the individual quality scoring of each article, eight studies were provided for meta-analysis of the cephalometric parameters. The statistical analysis of treatment changes advocates a positive influence on sagittal maxillary development, which is not primarily influenced by transverse expansion. Dental side effects are more distinct when no expansion was carried out. For the concept of alternating activation/deactivation of the expansion appliance (alt-RAMEC), two articles of high methodological scoring were identified. They indicate an enhancement of face mask treatment.
  
  
  CONCLUSIONS
  The findings are consistent with results of previous literature studies regarding the efficiency of class III face mask treatment. A further need for more randomized controlled studies was identified especially with regard to the new concept of alternating maxillary expansion and compression, which showed a positive influence on the maxillary protraction based on two studies.
  
  
  CONCLUSIONS
  Class III therapy using extraoral face mask anchorage is effective for maxillary protraction. The recently discussed new protocols potentially improve this treatment.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Johannes Gutenberg-University Mainz Medical Center, Augustusplatz 2, 55131, Mainz, Germany, moritz.foersch@unimedizin-mainz.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Foersch
authors.forename: Collin
authors.initials: C
authors.lastname: Jacobs
authors.forename: Susanne
authors.initials: S
authors.lastname: Wriedt
authors.forename: Marlene
authors.initials: M
authors.lastname: Hechtner
authors.forename: Heinrich
authors.initials: H
authors.lastname: Wehrbein
mesh_terms: D005115:Extraoral Traction Appliances; D006801:Humans; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D016382:Orthodontic Appliance Design; D057887:Overbite / Q000628:therapy*; D010155:Palatal Expansion Technique