External apical root resorption in patients treated with conventional and self-ligating brackets

Am J Orthod Dentofacial Orthop. 2008 Nov;134(5):646-51. doi: 10.1016/j.ajodo.2007.01.032.


Introduction: Our aim was to comparatively investigate the amount of external apical root resorption (EARR) between conventional and passive self-ligating brackets.

Methods: Ninety-six patients were selected from a pool of patients satisfying the following inclusion criteria: no evidence of resorption on the pretreatment panoramic radiographs; no contributing history of trauma; no dilacerations of lateral incisor roots, maxillary anodontia, and impacted canines; complete root formation at the start of treatment; intact and caries-free maxillary incisors; and no endodontically treated incisors. Patients received treatment with either a passive self-ligating bracket system or a conventional edgewise appliance, both with a 0.022-in slot. EARR of the maxillary incisors was evaluated on panoramic radiographs, taken before and after orthodontic treatment measured in millimeters. Distortion of measurements caused by panoramic radiographs was investigated by using a calibrated periodontal probe attached to the lateral incisor, and the extent of magnification was estimated to be 14%. Statistical comparisons of EARR between appliance type, age, sex, extraction treatment, and duration of treatment were investigated with univariate and multivariate regression modeling.

Results: Overall, no difference was found in the amount of EARR between appliance systems. Age, sex, and extraction treatment were not reliable predictors of EARR, but a positive association between EARR and duration of treatment was observed.

Conclusions: No difference should be expected for root resorption between conventional and passive self-ligating brackets.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Child
  • Cohort Studies
  • Female
  • Humans
  • Incisor / diagnostic imaging
  • Incisor / pathology
  • Male
  • Malocclusion / therapy
  • Maxilla
  • Orthodontic Appliance Design
  • Orthodontic Brackets / adverse effects*
  • Orthodontic Brackets / classification
  • Orthodontic Wires / adverse effects
  • Orthodontics, Corrective / adverse effects
  • Orthodontics, Corrective / instrumentation*
  • Orthodontics, Corrective / methods
  • Radiography
  • Root Resorption / diagnostic imaging
  • Root Resorption / etiology*
  • Statistics, Nonparametric
  • Stress, Mechanical
  • Tooth Apex / diagnostic imaging
  • Tooth Apex / pathology*
  • Tooth Movement Techniques / adverse effects
  • Tooth Movement Techniques / instrumentation