title: Stability and relapse of maxillary anterior crowding treatment in class I and class II Division 1 malocclusions.
abstract: BACKGROUND
  The maxillary anterior teeth are the most important to facial esthetics because they are the first to show on a smile. Therefore, stability of the maxillary anterior teeth alignment is an important issue. The objective of this study was to compare the stability of maxillary anterior tooth alignment in Class I and Class II Division 1 malocclusions.
  
  
  METHODS
  The sample comprised dental casts of 70 patients with Class I and Class II Division 1 malocclusions and a minimum of 3 mm of maxillary anterior crowding measured by an irregularity index. The patients were treated with extractions and evaluated at pretreatment and posttreatment and at least 5 years after treatment. The sample was divided into 3 groups: group 1, Class I malocclusion treated with 4 first premolar extractions comprising 30 subjects, with an initial age of 13.16 years and 8.59 mm of initial maxillary irregularity; group 2, Class II malocclusion treated with 4 first premolar extractions comprising 20 subjects, with an initial age of 12.95 years and 11.10 mm of maxillary irregularity; and group 3, Class II malocclusion treated with 2 first maxillary premolar extractions comprising 20 subjects, with an initial age of 13.09 years and 9.68 mm of maxillary irregularity.
  
  
  RESULTS
  The decrease in the maxillary irregularity index was significantly greater in group 2 than in group 1 during treatment. The stability of maxillary anterior alignment was 88.12% over the long term; 77% of the linear displacement of the anatomic contact points tended to return to their original positions.
  
  
  CONCLUSIONS
  Stability of maxillary anterior alignment between the 3 groups was similar. The stability of maxillary anterior alignment was high over the long term, but a high percentage of teeth tended to return to their original positions.
authors.affiliation: Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil. cquaglio@yahoo.com.br.
authors.forename: Camila Leite
authors.initials: CL
authors.lastname: Quaglio
authors.forename: Karina Maria Salvatore
authors.initials: KM
authors.lastname: de Freitas
authors.forename: Marcos Roberto
authors.initials: MR
authors.lastname: de Freitas
authors.forename: Guilherme
authors.initials: G
authors.lastname: Janson
authors.forename: José Fernando Castanha
authors.initials: JF
authors.lastname: Henriques
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000601:surgery; D002508:Cephalometry; D002648:Child; D003481:Cuspid / Q000473:pathology*; D003724:Dental Arch / Q000473:pathology; D005115:Extraoral Traction Appliances; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology*; D008297:Male; D008311:Malocclusion, Angle Class I / Q000473:pathology / Q000628:therapy*; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy*; D008437:Maxilla / Q000473:pathology; D052280:Orthodontic Anchorage Procedures; D018704:Orthodontic Retainers; D012008:Recurrence; D012189:Retrospective Studies; D012690:Serial Extraction; D014087:Tooth Movement Techniques / Q000295:instrumentation; D016896:Treatment Outcome