title: [Comparative study of the clinical effects of three different functional appliances on the treatment of skeletal class II malocclusion].
abstract: OBJECTIVE
  To evaluate whether there was any difference on the clinical effects of Twin-block, Activator and Herbst appliances on the clinical effects of growing children with skeletal Class II malocclusion.
  
  
  METHODS
  60 patients with skeletal Angle Class II malocclusion were divided into three groups (Twin-block group, Activator group, Herbst group), 20 in each group. The patients of three groups were respectively treated by Twin-block, Activator and Herbst appliances. The patients were 10-13 years old(mean 11.6) before treatment, and were mainly with mandibular retrognathia. Data of pre- and post-treatment were measured and analyzed.
  
  
  RESULTS
  There was statistically significance of ANB, SNB, Go-Gn, Co-Gn, L1-MP in sagittal changes, and N-Me, ANS-Me, S-Go, SN-MP, Co-Go in vertical changes after treatment of three groups. Herbst group was more effective than Twin-block group and Activator group in the increase of L1-MP, but the effects on maxilla were not significant among them. There was no statistical significance of Ptm-A, OB, N-Me, ANS-Me, S-Go and Co-Go between 3 groups.
  
  
  CONCLUSIONS
  Treatment effects of three different functional appliances (Twin-block, Activator and Herbst) are similar in the early treatment of skeletal Class II malocclusion. Compared with Twin-block and Activator, Herbst has more effects on orthopedic of mandibular and lower anterior teeth.
authors.affiliation: Dept. of Stomatology, Affliated Municipal Hospital of Qingdao University, Qingdao 266011, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Song
authors.forename: Yan-ling
authors.initials: YL
authors.lastname: Yu
authors.forename: Hong
authors.initials: H
authors.lastname: Shen
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II; D008334:Mandible; D008437:Maxilla; D017289:Orthodontic Appliances, Functional