title: An ex vivo culture model for orthodontically induced root resorption.
abstract: OBJECTIVE
  Root resorption is a ubiquitous although undesirable sequela to orthodontic treatment. Current methods to investigate the pathophysiology have certain limitations. In pursuit to understand and develop treatment modalities for orthodontically induced root resorption, the ability to manipulate cells within their natural extracellular matrix in a three dimensional organotypic model is invaluable. The study aimed to develop a laboratory-based organotypic model to investigate the effect of orthodontic forces on the periodontium.
  
  
  METHODS
  Mandibular slices of male Wistar rats were maintained in Trowel-typed cultures at 37°C in 5% carbon dioxide in air for 7 days with test specimens subjected to compressive forces at 50 g and 100g by stainless steel springs. Tissue architecture and cell viability were maintained under culture conditions.
  
  
  RESULTS
  Osteoclast numbers increased significantly in both test groups whilst odontoclasts increased in the 50 g group. Immunohistochemistry demonstrated increased dentine sialoprotein expression in both test groups, suggesting changes in mineralization-related activity due to mechanical strain.
  
  
  CONCLUSIONS
  The study showed initial cellular and molecular changes of key markers that relate to root resorption in response to mechanical loading.
  
  
  CONCLUSIONS
  Severe root resorption may occur when forces applied are heavy or transmitted over an extended period and could lead to mobility and tooth loss. This ex vivo model can be used to investigate cellular and molecular processes during orthodontic tooth movement which may advance the clinical management of root resorption.
authors.affiliation: Department of Children's Dentistry and Orthodontics, University of Malaya, Kuala Lumpur, Malaysia. wannurazreena@um.edu.my
authors.forename: W N
authors.initials: WN
authors.lastname: Wan Hassan
authors.forename: P A
authors.initials: PA
authors.lastname: Stephenson
authors.forename: R J
authors.initials: RJ
authors.lastname: Waddington
authors.forename: A J
authors.initials: AJ
authors.lastname: Sloan
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001696:Biomechanical Phenomena; D001853:Bone Marrow / Q000033:anatomy & histology / Q000473:pathology; D002452:Cell Count; D002470:Cell Survival / Q000502:physiology; D003782:Dental Pulp / Q000033:anatomy & histology; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins / Q000032:analysis; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000166:cytology; D009924:Organ Culture Techniques; D009969:Orthodontic Wires; D010010:Osteoclasts / Q000145:classification / Q000473:pathology; D010513:Periodontal Ligament / Q000033:anatomy & histology / Q000166:cytology; D010750:Phosphoproteins / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D012391:Root Resorption / Q000209:etiology* / Q000473:pathology; D012795:Sialoglycoproteins / Q000032:analysis; D013314:Stress, Mechanical; D000071681:Tartrate-Resistant Acid Phosphatase; D014087:Tooth Movement Techniques / Q000295:instrumentation*; D000099311:Dentin Sialophosphoprotein
chemical_list: D000135:Acid Phosphatase; D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D007527:Isoenzymes; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000071681:Tartrate-Resistant Acid Phosphatase; D000099311:Dentin Sialophosphoprotein