title: Changes in condylar cartilage after anterior mandibular displacement in juvenile pigs.
abstract: Adaptive remodelling of the mandibular condyle in response to mandibular advancement is the mechanism exploited by orthodontic forward displacement devices.
  
  
  OBJECTIVE
  This work investigated the expression of collagens, matrix metalloproteinases and vascular endothelial growth factor during this process.
  
  
  METHODS
  Twenty juvenile pigs were randomly divided into two experimental groups, where the treatment group was fitted with mandibular advancement splints, and the control group was not. Changes in the mRNA content of condylar cartilage tissue was then were measured by real-time PCR using specific primers after 4weeks of treatment.
  
  
  RESULTS
  The temporal pattern of the expression of Col1 and MMP13 during condylar adaptation coincided with that during natural condylar growth. The amount of the expression of Col10 during condylar adaptation was significantly lower (p<0.05), whereas the expression of Col2, MMP8 and VEGF was significantly higher compared to natural growth (p<0.05).
  
  
  CONCLUSIONS
  It is suggested that condylar adaptation in growing pigs triggered by mandibular forward positioning results not only from passive adaptation of cartilage, but also involves growth affected processes. Our results showed that mechanical strain produced by mandibular advancement induced remodelling and revascularization in the posteriocranial mandibular condyle. These results are mostly consistent with former published histological and histomorphometrical analyses.
authors: Department of Orthodontics, Faculty of Medicine, University of Greifswald, Greifswald, Germany. thomasgredes@yahoo.de
authors: Tomasz
authors: T
authors: Gredes
authors: Heike
authors: H
authors: Mack
authors: Alexander
authors: A
authors: Spassov
authors: Christiane
authors: C
authors: Kunert-Keil
authors: Matthew
authors: M
authors: Steele
authors: Peter
authors: P
authors: Proff
authors: Florian
authors: F
authors: Mack
authors: Tomasz
authors: T
authors: Gedrange
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D016723:Bone Remodeling; D002356:Cartilage / Q000033:anatomy & histology / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D019186:Mandibular Advancement; D008335:Mandibular Condyle / Q000033:anatomy & histology / Q000378:metabolism*; D020782:Matrix Metalloproteinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction; D013314:Stress, Mechanical; D013552:Swine; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D020782:Matrix Metalloproteinases