title: Characterization of tissue components in the temporomandibular joint disc and posterior disc attachment region: internal derangement and control autopsy specimens compared by morphometry.
abstract: OBJECTIVE
  Our aim was to morphologically investigate the occurrence of fibroblasts, chondrocytes, and blood vessels in the tissue of the temporomandibular joint (TMJ) disc, the intermediate zone, and the posterior disc attachment region in control autopsy specimens and to compare the results with those observed in corresponding tissues from patients with TMJ internal derangement.
  
  
  METHODS
  First, 20 bilateral TMJ disc specimens from selected autopsy cases were analyzed by conventional morphometry. Thus, the volume density of fibroblasts, chondrocytes, and blood vessels was determined. Second, the obtained results from the right joint of the autopsy disc specimens were compared with 12 TMJ disc specimens obtained at surgery from patients with internal derangement.
  
  
  RESULTS
  The tissue compartments of interest (disc, intermediate zone, and posterior disc attachment region) were identified unequivocally in all specimens. None of the autopsy cases showed any significant difference between the right and left joints or related to gender. The only variable that differed between autopsy and patient specimens was volume density of blood vessels, which was higher in patient specimens.
  
  
  CONCLUSIONS
  We found that the volume density of blood vessels was significantly higher in the posterior disc attachment region in patient specimens than in autopsy controls. Whether this reflects a role for vessels in the pathogenesis of TMJ internal derangement or merely is a reaction to another type of injury remains to be settled. In both the autopsy control and patient specimens, chondrocytes and fibroblasts were characteristic for disc respective posterior disc attachment region. Thus it appears that the occurrence of these cells can be used to distinguish TMJ disc from posterior disc attachment in small biopsy specimens.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Karolinska Institute, Huddinge, Sweden.
authors.forename: Diana I
authors.initials: DI
authors.lastname: Paegle
authors.forename: Anders B
authors.initials: AB
authors.lastname: Holmlund
authors.forename: Finn P
authors.initials: FP
authors.lastname: Reinholt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002358:Cartilage, Articular / Q000098:blood supply / Q000473:pathology; D019902:Chondrocytes / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D013583:Synovial Membrane / Q000473:pathology; D019224:Temporomandibular Joint Disc / Q000098:blood supply* / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000473:pathology*