title: Displacement of the temporomandibular joint disk: correlation between clinical findings and MRI characteristics.
abstract: OBJECTIVE
  Disk displacement frequently causes dysfunction of the temporomandibular joint (TMJ). Magnetic resonance imaging (MRI) of the TMJ is 95% accurate in the assessment of disk position and form. Various restorative procedures are used for treatment of disk displacement. However, several authors have noted a lack of correlation between MRI findings of disk displacement and the extent of pain and dysfunction of the TMJ. The purpose of this study was to evaluate whether MRI findings of various degrees of disk displacement could be correlated with the presence of clinical signs and symptoms in patients with a clinical disorder of the TMJ.
  
  
  METHODS
  One hundred and forty-four TMJs (in 72 patients) were imaged. Displacement of the posterior band in relation to the condyle was quantified as mild or significant.
  
  
  RESULTS
  Disk displacement was found in 45 (54%) of the 84 symptomatic joints and 13 (22%) of the 60 asymptomatic joints. Among the 84 symptomatic joints, 31 (37%) had disk displacement with reduction and 14 (17%) had disk displacement without reduction. In the latter group, 11 (79%) of the 14 joints had significant displacement of the posterior band (8 or 9 o'clock) and 21% had mild displacement of the posterior band (10 o'clock). Of the 60 clinically asymptomatic joints, 47 (78%) had no signs of disk displacement on MRI, whereas 13 (22%) had disk displacement with reduction. None of the asymptomatic joints had disk displacement without reduction. The difference in occurrence of disk displacement between symptomatic and asymptomatic joints was statistically significant (54% vs. 22%; p < 0.001). However, the difference in occurrence of disk displacement with reduction of the disk on mouth opening was not statistically significant (37% vs. 22%; p = 0.06).
  
  
  CONCLUSIONS
  Disk displacement on MRI correlated well with clinical symptoms in cases of significant disk displacement and in cases of disk displacement without reduction. When disk displacement with reduction was mild, there was no statistically significant difference between symptomatic and asymptomatic joints, which suggests that other causes should be considered.
authors.affiliation: Department of Radiology, McMaster University Medical Centre, Hamilton, Ontario. zeev25@yahoo.com
authors.forename: Zeev V
authors.initials: ZV
authors.lastname: Maizlin
authors.forename: Nicoleta
authors.initials: N
authors.lastname: Nutiu
authors.forename: Peter B
authors.initials: PB
authors.lastname: Dent
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Vos
authors.forename: David M
authors.initials: DM
authors.lastname: Fenton
authors.forename: John M
authors.initials: JM
authors.lastname: Kirby
authors.forename: Parag
authors.initials: P
authors.lastname: Vora
authors.forename: Jean H
authors.initials: JH
authors.lastname: Gillies
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Clement
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D004204:Joint Dislocations / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015588:Observer Variation; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D019224:Temporomandibular Joint Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D055815:Young Adult