title: [OPG and OPGL expression in condyle cartilage of temporomandibular joint following anterior disc displacement].
abstract: OBJECTIVE
  To investigate the change of osteoprotegerin (OPG) and OPGL expression and its significance in condylar cartilage after anterior disc displacement (ADD).
  
  
  METHODS
  Twenty healthy adult Japanese rabbits (from medical animal center of Zhejiang University) weighing from 2 to 3 kg were used in this study. Sixteen rabbits were subjected to surgical anterior disc displacement in the right temporomandibular joints (TMJ), four rabbits were sacrificed 1, 2, 4, 8 weeks post-operation,respectively; two rabbits with sham-operation and two without operation were as control. The structure of temporomandibular joint was observed under microscope. The expression of OPG and OPGL in condylar cartilage were examined by S-P immunohistochemical staining and measured with Image Computer Analysis Software. Date was statistically analyzed by one-way ANOVA.
  
  
  RESULTS
  Experimental and sham-operative animals tolerated the surgical procedures well. The discs displaced anteriorly were observed in the surgical rabbits by general and microscope observation. The expression of OPG and OPGL was detected in the proliferating zone and hypertrophy zone cells of condyle in all animals. However, the expression of OPG and OPGL was stronger in the surgical group. There was significant difference in average gray degree (P<0.05) between the experimental and control groups. The ratio of OPG/OPGL was stable.
  
  
  CONCLUSIONS
  The expression of OPG and OPGL in condylar cartilage was increased after ADD. They might play a role in the development and prognosis of the temporomandibular condylar cartilage alteration after ADD.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Hospital of Stomatology, Zhejiang University, Hangzhou 310006, Zhejiang Province, China.
authors.forename: Yi-qun
authors.initials: YQ
authors.lastname: Zhou
authors.forename: Ji-an
authors.initials: JA
authors.lastname: Hu
authors.forename: Zhi-yuan
authors.initials: ZY
authors.lastname: Gu
authors.forename: Yi-ning
authors.initials: YN
authors.lastname: Li
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D053244:Osteoprotegerin / Q000378:metabolism*; D053245:RANK Ligand / Q000378:metabolism*; D011817:Rabbits; D019224:Temporomandibular Joint Disc / Q000378:metabolism / Q000473:pathology*
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand