title: Surgical induction of TMJ bony ankylosis in growing sheep and the role of injury severity of the glenoid fossa on the development of bony ankylosis.
abstract: OBJECTIVE
  The purpose of this paper is to summarize our experiences in creating an animal model of TMJ bony ankylosis based on 2 sequential experiments.
  
  
  METHODS
  Two sequential experiments were performed with the aim of creating a model of TMJ bony ankylosis. Seven growing sheep were used in the first experiment, in which 1 was served as a control animal. Condylar fracture with disc preservation was performed on the control side. On the contralateral side, condylar fracture, excision of the lateral 2/3 disc and injury to the glenoid fossa were performed to induce bony ankylosis. Three animals were sacrificed respectively at 3 and 6 months after surgery. In the second experiment, 7 growing sheep were used. The only difference of modeling between the 2 experiments was that more serious injury to the glenoid fossa was made in the ankylosis-induced side in experiment 2. Three, 2, and 2 animals were sacrificed respectively at 1, 3, and 6 months postoperatively. The TMJ complexes were examined by computed tomography (CT) and histological evaluation.
  
  
  RESULTS
  In experiment 1, only fibrous ankylosis was observed in the ankylosis-induced side both at 3 and 6 months postoperatively. In experiment 2, CT and histological evaluation showed that the outcomes of the ankylosis-induced side were fibrous-bony ankylosis, fibrous-bony ankylosis, and bony ankylosis respectively at 1, 3, and 6 months after surgery.
  
  
  CONCLUSIONS
  Through summarizing the differences of the modeling and the different outcomes in the 2 experiments, we concluded that severe damage to the glenoid fossa played an important role in the development of TMJ bony ankylosis.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, PR China.
authors.forename: Ying-Bin
authors.initials: YB
authors.lastname: Yan
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ye-Hua
authors.initials: YH
authors.lastname: Gan
authors.forename: Jin-Gang
authors.initials: JG
authors.lastname: An
authors.forename: Jiang-Ming
authors.initials: JM
authors.lastname: Li
authors.forename: E
authors.initials: E
authors.lastname: Xiao
mesh_terms: D000818:Animals; D000844:Ankylosis / Q000209:etiology*; D001861:Bone Regeneration / Q000502:physiology; D016723:Bone Remodeling / Q000502:physiology; D002114:Calcinosis / Q000209:etiology; D002358:Cartilage, Articular / Q000473:pathology; D003238:Connective Tissue / Q000473:pathology; D004195:Disease Models, Animal; D004435:Eating / Q000502:physiology; D005355:Fibrosis; D004204:Joint Dislocations / Q000150:complications; D008297:Male; D008335:Mandibular Condyle / Q000293:injuries; D008337:Mandibular Fractures / Q000150:complications; D010026:Osteosclerosis / Q000209:etiology; D016059:Range of Motion, Articular / Q000502:physiology; D012756:Sheep; D013701:Temporal Bone / Q000293:injuries*; D019224:Temporomandibular Joint Disc / Q000293:injuries; D013705:Temporomandibular Joint Disorders / Q000209:etiology*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D014945:Wound Healing / Q000502:physiology