title: [Effect of orthodontic force on periodontal healing after autotransplantation: an experimental study].
abstract: OBJECTIVE
  To investigate the effect of the continuous light force to the donor teeth on the periodontal healing after transplantation.
  
  
  METHODS
  Thirty-two maxillary and mandibular incisors in four 10-month-old male Beagle dogs were autotransplanted. The pulps were removed in all teeth. The teeth were divided into four groups, one control and three experimental groups. In control group (group 1), the teeth were unloaded. In the other three experimental groups, continuous force (0.49 N) was applied in the 1st (group 2), 2nd (group 3) and 4th (group 4) week, respectively. The dogs were sacrificed in the 8th week. The tissue blocks were demineralized and sectioned perpendicular to the long axis of the teeth. The histological analysis was made.
  
  
  RESULTS
  Histomophometric analysis revealed a significantly lower occurrence of replacement root resorption in the group 3 (2.1%) than in the control group (12.5%, P < 0.05). The significant lower incidence of replacement root resorption, and a higher surface and inflammatory root resorption were found in group 2 (6.3% and 68.8%) than in the control group (12.5% and 41.7%, P < 0.05). No significant difference was found between group 4 and control group (P > 0.05).
  
  
  CONCLUSIONS
  The orthodontic force promoted the regeneration of the periodontal ligament and prevented dentoalveolar ankylosis, whereas excessive initial force might cause root and bone resorption.
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing 100050, China. byuxing@263.net
authors.forename: Yun
authors.initials: Y
authors.lastname: Yang
authors.forename: Yu-xing
authors.initials: YX
authors.lastname: Bai
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Wei-min
authors.initials: WM
authors.lastname: Gao
authors.forename: Nan
authors.initials: N
authors.lastname: Ru
authors.forename: Li-xuan
authors.initials: LX
authors.lastname: Li
mesh_terms: D000818:Animals; D004285:Dogs; D007180:Incisor / Q000637:transplantation*; D008297:Male; D050793:Orthodontic Extrusion; D010513:Periodontal Ligament / Q000502:physiology; D012391:Root Resorption / Q000209:etiology*; D014090:Tooth Replantation / Q000009:adverse effects; D014182:Transplantation, Autologous; D014945:Wound Healing