title: Correlation between mandibular incisor crown morphologic index and postretention stability.
abstract: BACKGROUND
  Considering postretention stability as a result of successful orthodontic treatment, we aimed to verify the influence of mandibular-incisor-crown morphology in the relapse of mandibular anterior crowding.
  
  
  METHODS
  The sample comprised 56 white subjects of both sexes with Class I and Class II malocclusions at pretreatment, treated with extraction of 4 first premolars and edgewise mechanics. No patient underwent interproximal stripping during or after treatment. Mean pretreatment age was 13.23 years. Mean treatment time was 2.11 years, and mean posttreatment evaluation time was 5.12 years. Mandibular anterior crowding was measured with the Little irregularity index, and the mesiodistal and buccolingual proportion of the mandibular incisor crowns was measured with the Peck and Peck index. The measurements were obtained from dental casts at the pretreatment, posttreatment, and postretention stages. The Pearson correlation coefficient was calculated to determine the correlation between mandibular-incisor-crown morphology and the amount of postretention-crowding relapse.
  
  
  RESULTS
  The mandibular-incisor-crown morphologic index was not significantly correlated with the amount of mandibular-anterior-crowding relapse.
  
  
  CONCLUSIONS
  Mandibular-incisor-crown morphology is not correlated with the amount of mandibular-anterior-crowding relapse.
authors.affiliation: Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil.
authors.forename: Marcos Roberto de
authors.initials: MR
authors.lastname: Freitas
authors.forename: Renata Cristina Faria Ribeiro de
authors.initials: RC
authors.lastname: Castro
authors.forename: Guilherme
authors.initials: G
authors.lastname: Janson
authors.forename: Karina Maria Salvatore
authors.initials: KM
authors.lastname: Freitas
authors.forename: José Fernando Castanha
authors.initials: JF
authors.lastname: Henriques
mesh_terms: D000293:Adolescent; D000465:Algorithms; D005260:Female; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology*; D008297:Male; D008310:Malocclusion / Q000503:physiopathology* / Q000628:therapy; D008334:Mandible; D003765:Models, Dental; D009811:Odontometry; D018704:Orthodontic Retainers; D012008:Recurrence; D019228:Tooth Crown / Q000033:anatomy & histology*