title: The role of the disk in sheep temporomandibular joint ankylosis.
abstract: OBJECTIVE
  The purpose of this study was to determine the role of the disk in intraarticular ankylosis of the temporomandibular joint.
  
  
  METHODS
  Twelve adult sheep were divided into 2 groups. In group 1, removal of the temporal and condylar articular surfaces was performed on the right temporomandibular joint and the disk was maintained; in group 2, removal of the articular surfaces and diskectomy were performed on the right temporomandibular joint. One sheep from each group was killed just after surgery and 5 sheep from each group were killed at 3 months. The joints were examined radiologically, macroscopically, and histologically. The range of jaw movements was recorded preoperatively and at sacrifice.
  
  
  RESULTS
  Each of 2 sheep in group 2 had lost 4% of their body weight by 3 months; all of the other sheep maintained or increased their weight. The range of jaw motion to the right was significantly lower in group 2 than in group 1 (P<.01). In group 1, fibrous repair of the articular surface and regeneration of the condylar head was seen. In group 2, each of the joints showed a total fibrous ankylosis with some calcification. There was a statistically significant difference in radiologic score between the groups (P<.0001). Histologic scores for group 1 demonstrated significantly lower scores on the degree of ankylosis scale and degree of calcification scale (P<.0001).
  
  
  CONCLUSIONS
  This study showed that the presence of the disk prevented the development of fibrous intraarticular ankylosis of the temporomandibular joint.
authors.affiliation: Department of Dentistry, University of Adelaide, Australia.
authors.forename: H
authors.initials: H
authors.lastname: Miyamoto
authors.forename: K
authors.initials: K
authors.lastname: Kurita
authors.forename: N
authors.initials: N
authors.lastname: Ogi
authors.forename: J I
authors.initials: JI
authors.lastname: Ishimaru
authors.forename: A N
authors.initials: AN
authors.lastname: Goss
mesh_terms: D000818:Animals; D000844:Ankylosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D001835:Body Weight; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology / Q000601:surgery; D005355:Fibrosis; D005500:Follow-Up Studies; D008335:Mandibular Condyle / Q000473:pathology / Q000503:physiopathology; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012038:Regeneration; D012756:Sheep; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D019224:Temporomandibular Joint Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology* / Q000601:surgery; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D014945:Wound Healing