title: Orthodontic tooth movement into jaw regions treated with synthetic bone substitute.
abstract: BACKGROUND
  Orthodontic tooth movement is fraught with risks and complications. Root resorption is the most frequent and important outcome which may arise due to inappropriate force magnitude or tooth movement into dense or altered bone. This study was aimed to demonstrate histologic changes in tooth roots following movement into a jaw region treated with synthetic bone substitute. Another objective was to evaluate the method of experimental tooth movement using an animal model.
  
  
  METHODS
  One mandibular premolar was extracted in each of three pigs (Sus scrofa domesticus). The extraction alveolus was filled with synthetic bone substitute material and a orthodontic appliance was attached for 90 days. The force for tooth movement was in the range of 1-2 N. Subsequently, specimens were collected using segmental osteotomy and were prepared histologically. Unmoved teeth served as controls.
  
  
  RESULTS
  Histological analysis showed clear lacuna-like lesions in the root surface area of all specimens. The lesions were largest in the apical area, while the mid-root region was less affected.
  
  
  CONCLUSIONS
  Due to deformations of the orthodontic tooth moving appliance, the force could not be exactly defined. Therefore, marked resorption lesions of the root surfaces cannot be unequivocally attributed to the synthetic bone substitute. However, the type of lesions on root surfaces permits the assumption that orthodontic tooth movement into areas filled with synthetic bone substitute may be associated with an increased risk of root resorption.
authors.affiliation: Department of Orthodontics, Preventive and Paediatric Dentistry, Centre of Dentistry and Oral Health, Ernst Moritz Arndt University Greifswald Rotgerberstr. 8, D-17489 Greifswald, Germany.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Gedrange
authors.forename: Tomasz
authors.initials: T
authors.lastname: Gredes
authors.forename: Alexander
authors.initials: A
authors.lastname: Spassow
authors.forename: Ronald
authors.initials: R
authors.lastname: Mai
authors.forename: Sergio
authors.initials: S
authors.lastname: Alegrini
authors.forename: Marzena
authors.initials: M
authors.lastname: Dominiak
authors.forename: Christiane
authors.initials: C
authors.lastname: Kunert-Keil
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Heinemann
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000009:adverse effects*; D023421:Models, Animal; D009967:Orthodontic Appliances / Q000009:adverse effects; D012391:Root Resorption / Q000209:etiology / Q000473:pathology* / Q000517:prevention & control; D013552:Swine; D014085:Tooth Migration / Q000150:complications / Q000473:pathology* / Q000628:therapy*; D014092:Tooth Root / Q000473:pathology*
chemical_list: D018786:Bone Substitutes