title: External apical root resorption in maxillary root-filled incisors after orthodontic treatment: a split-mouth design study.
abstract: BACKGROUND
  The purpose of this study was to compare, in a split mouth design, the external apical root resorption (EARR) associated with orthodontic treatment in root-filled maxillary incisors and their contralateral teeth with vital pulps.
  
  
  METHODS
  The study sample consisted of 38 patients (14 males and 24 females), who had one root-filled incisor before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the root resortion and the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the endodontically treated incisor and that in its contralateral incisor with a vital pulp. The student's t-test, chi-square test and logistic regression analysis were used to determine statistical significance.
  
  
  RESULTS
  There was no statistically significant difference (p > 0.05) between EARR in vital teeth (1.1 ± 1.0 mm) and endodontically treated incisors (1.1 ± 0.8 mm). Twenty-six patients (68.4%) showed greater resorption of the endodontically treated incisor than its homolog vital tooth (p > 0.05). The mean and standard deviation of PPR were 1.0 ± 0.2. Multivariate logistic regression suggested that PRR does not correlate with any of the variables analyzed.
  
  
  CONCLUSIONS
  There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root-filled incisors and their contralateral teeth with vital pulps.
authors.affiliation: Department of Orthodontics, School of Dentistry, University of Seville, Seville, Spain. jmllamas@us.es
authors.forename: José María
authors.initials: JM
authors.lastname: Llamas-Carreras
authors.forename: Almudena
authors.initials: A
authors.lastname: Amarilla
authors.forename: Eduardo
authors.initials: E
authors.lastname: Espinar-Escalona
authors.forename: Lizett
authors.initials: L
authors.lastname: Castellanos-Cosano
authors.forename: Jenifer
authors.initials: J
authors.lastname: Martín-González
authors.forename: Benito
authors.initials: B
authors.lastname: Sánchez-Domínguez
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: López-Frías
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D008437:Maxilla; D016910:Orthodontic Brackets; D012389:Root Canal Obturation; D012391:Root Resorption; D019227:Tooth Apex