title: Treatment stability in patients with Class II malocclusion treated with 2 maxillary premolar extractions or without extractions.
abstract: BACKGROUND
  The purpose of this study was to compare the occlusal stability of Class II malocclusion treatment with and without extraction of 2 maxillary premolars.
  
  
  METHODS
  A sample of 59 records from patients with complete Class II malocclusion was used. This sample was divided into 2 groups with the following characteristics: group 1, comprising 29 patients treated without extractions, and group 2, comprising 30 patients treated with extraction of 2 maxillary premolars. Dental cast measurements were obtained before and after treatment and at a minimum of 2.4 years after treatment. The pretreatment, posttreatment, and postretention occlusal statuses were evaluated with the peer assesment rating index. The occlusal indexes at the postretention stage and the posttreatment changes and percentages of posttreatment changes were compared with t tests.
  
  
  RESULTS
  The nonextraction and the 2 maxillary premolar extraction treatment protocols of complete Class II malocclusions had no statistically significant differences in occlusal stability.
  
  
  CONCLUSIONS
  Finishing Class II malocclusion treatment with the molars in a Class II relationship has similar occlusal stability as finishing with the molars in a Class I relationship.
authors.affiliation: Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil. jansong@travelnet.com.br
authors.forename: Guilherme
authors.initials: G
authors.lastname: Janson
authors.forename: Leonardo Tavares
authors.initials: LT
authors.lastname: Camardella
authors.forename: Janine Della Valle
authors.initials: JD
authors.lastname: Araki
authors.forename: Marcos Roberto
authors.initials: MR
authors.lastname: de Freitas
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Pinzan
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000601:surgery; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D003765:Models, Dental; D009971:Orthodontics, Corrective / Q000379:methods*; D010380:Peer Review; D012008:Recurrence; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014081:Tooth Extraction; D016896:Treatment Outcome