title: The Effect of An Angiogenic Cytokine on Orthodontically Induced Inflammatory Root Resorption.
abstract: OBJECTIVE
  Orthodontically induced inflammatory root resorption (OIIRR) is an undesirable sequel of tooth movement after sterile necrosis that takes place in periodontal ligament due to blockage of blood vessels following exertion of orthodontic force. This study sought to assess the effect of an angiogenic cytokine on OIIRR in rat model.
  
  
  METHODS
  In this experimental animal study, 50 rats were randomly divided into 5 groups of 10 each: E10, E100 and E1000 receiving an injection of 10, 100 and 1000 ng of basic fibroblast growth factor (bFGF), respectively, positive control group (CP) receiving an orthodontic appliance and injection of phosphate buffered saline (PBS) and the negative control group (CN) receiving only the anesthetic agent. A nickel titanium coil spring was placed between the first molar and the incisor on the right side of maxilla. Twenty-one days later, the rats were sacrificed. Histopathological sections were made to assess the number and area of resorption lacunae, number of blood vessels, osteoclasts and Howship's lacunae. Data were statistically analyzed using ANOVA and Tukey's honest significant difference (HSD) test.
  
  
  RESULTS
  Number of resorption lacunae and area of resorption lacunae in E1000 (0.97 ± 0.80 and 1. 27 ± 0.01×10(-3), respectively) were significantly lower than in CP (4.17 ± 0.90 and 2.77 ± 0.01×10-3, respectively, P=0.000). Number of blood vessels, osteoclasts and Howship's lacunae were significantly higher in E1000 compared to CP (P<0.05).
  
  
  CONCLUSIONS
  Tooth movement as the outcome of bone remodeling is concomitant with the formation of sterile necrosis in the periodontal ligament following blocked blood supply. Thus, bFGF can significantly decrease the risk of root resorption by providing more oxygen and angiogenesis.
authors.affiliation: Department of Orthodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Massoud
authors.initials: M
authors.lastname: Seifi
authors.affiliation: Department of Oral and Maxillofacial Pathology, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Lotfi
authors.affiliation: Dentofacial Deformities Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Science, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Badiee
authors.affiliation: Department of Pedodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Abdolazimi
authors.affiliation: Department of Dental Materials, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Amdjadi
authors.affiliation: Department of Pedodontics, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Bargrizan
keywords: Angiogenesis; Basic Fibroblast Growth Factor; Rat; Root Resorption