title: [Effect on functional appliances on mandibular growth on skeletal Class II malocclusion: a systematic review].
abstract: OBJECTIVE
  To examine the hypothesis that functional appliances enhance mandibular growth in the treatment of skeletal Class II malocclusion.
  
  
  METHODS
  A literature search was performed in electronic databases according key words "skeletal Class II malocclusion" , and full texts of selected articles were collected by hand-made method. The data were extracted from the articles. The quality of the trials was evaluated and meta-analysis method was used to analyze the data through RevMan 4.2.
  
  
  RESULTS
  19 articles could be qualified for the final analysis. Those indices including SNB (Activator, Twin-block, Herbst group), Go-Gn, Co-Pg, Co-Gn, Co-Go, demonstrated significant effect of functional appliances on mandibular growth in comparing with those of untreated control group. There were no significant differences between the two groups for the indicies of SNB (Fränkel-II) and Go-Me.
  
  
  CONCLUSIONS
  Functional appliances can enhance mandibular growth in treatment of skeletal Class II malocclusion. This mainly dues to the growth of the ramus instead of changes of mandibular body length.
authors.affiliation: Dept. of Orthodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.
authors.forename: Yirui
authors.initials: Y
authors.lastname: Niu
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
mesh_terms: D002508:Cephalometry; D006801:Humans; D008310:Malocclusion; D008312:Malocclusion, Angle Class II; D008334:Mandible; D017289:Orthodontic Appliances, Functional