title: Mandibular condylar cartilage response to moving 2 molars in rats.
abstract: BACKGROUND
  The purpose of this study was to investigate the responses of mandibular condylar cartilage to moving 2 molars in different combinations.
  
  
  METHODS
  Rats were assigned to male and female control and experimental groups (each, n = 5). Elastic rubber bands were used to move medially the maxillary left and the mandibular right first molars in experimental group I. The same method was used to distally move the maxillary left and the mandibular right third molars, 2 mandibular third molars, and 2 maxillary third molars in experimental groups II, III, and IV, respectively. At the end of the eighth week, all condyles were examined histologically. The areas of histologic change as a percentage of total cartilage area were compared by using the Mann-Whitney U test.
  
  
  RESULTS
  Cartilage degenerative remodeling was observed in experimental groups II, III, and IV. The percentage areas of degenerative remodeling were higher in female experimental groups II and III than in the female control group, and in female experimental group II than in female experimental group IV and male experimental group II (all, P <0.05).
  
  
  CONCLUSIONS
  The mandibular condylar cartilage of female rats responded variously to different combinations of molar movement; the most obvious remodeling was observed in groups in which the maxillary left and mandibular right third molars were moved.
authors.affiliation: Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Jiao
authors.forename: Mei-Qing
authors.initials: MQ
authors.lastname: Wang
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Niu
authors.forename: Juan
authors.initials: J
authors.lastname: Dai
authors.forename: Shi-Bin
authors.initials: SB
authors.lastname: Yu
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Liu
mesh_terms: D000818:Animals; D002357:Cartilage Diseases / Q000473:pathology / Q000503:physiopathology; D002358:Cartilage, Articular / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D049109:Cell Proliferation; D019902:Chondrocytes / Q000473:pathology; D003593:Cytoplasm / Q000473:pathology; D016326:Extracellular Matrix Proteins / Q000032:analysis; D005260:Female; D008297:Male; D008310:Malocclusion / Q000503:physiopathology*; D008335:Mandibular Condyle / Q000473:pathology / Q000503:physiopathology*; D008963:Molar / Q000473:pathology*; D008964:Molar, Third / Q000473:pathology; D009142:Musculoskeletal Physiological Phenomena; D009967:Orthodontic Appliances; D011509:Proteoglycans / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation
chemical_list: D016326:Extracellular Matrix Proteins; D011509:Proteoglycans