title: The diagnostic value of ultrasonography to determine the temporomandibular joint disk position.
abstract: OBJECTIVE
  Temporomandibular joint (TMJ) arthrography and magnetic resonance imaging are the imaging techniques of choice in patients presenting with signs and symptoms of TMJ disorders suggesting soft tissue pathosis. With the disadvantage of arthrography as an invasive procedure and magnetic resonance imaging posing a problem in clinical availability and cost, the purpose of this study was to determine whether ultrasonography could be used to assess the presence or absence of disk displacement in patients with TMJ disorders.
  
  
  METHODS
  In 17 patients, 100 TMJ positions were investigated by static and dynamic ultrasonography to analyze the disk-condyle relationship. To compare the respective findings with those of a diagnostic method offering high accuracy, coronal and sagittal magnetic resonance imaging was carried out immediately afterwards.
  
  
  RESULTS
  With static ultrasonography showing a sensitivity of 0.41 and a specificity of 0.70 and dynamic ultrasonography a sensitivity of 0.31 and a specificity of 0.95, the data revealed that static and dynamic ultrasonography are marginal in detecting the presence of disk displacement, but dynamic ultrasonography is sensitive in detecting the absence of disk displacement. However, with a positive predictive value of 0.61 and a negative predictive value of 0.51 for static ultrasonography, and a positive predictive value of 0.88 and a negative predictive value of 0.55 for the dynamic technique, the results indicate that both modalities are insufficient in establishing a correct diagnosis for the presence or absence of disk displacement.
  
  
  CONCLUSIONS
  In view of the fact that dynamic ultrasonography proved to be a reliable diagnostic aid for the detection of normal disk position, the results of this study should be of further interest and encourage research in its potential uses and diagnostic capabilities.
authors.affiliation: Department of Oral and Maxillo-Facial Surgery, University of Innsbruck, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Emshoff
authors.forename: S
authors.initials: S
authors.lastname: Bertram
authors.forename: A
authors.initials: A
authors.lastname: Rudisch
authors.forename: R
authors.initials: R
authors.lastname: Gassner
mesh_terms: D000293:Adolescent; D000328:Adult; D001175:Arthrography; D005157:Facial Pain / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000175:diagnosis / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging; D008875:Middle Aged; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging; D019224:Temporomandibular Joint Disc / Q000000981:diagnostic imaging* / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis / Q000000981:diagnostic imaging*; D014159:Transducers; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods