title: The relationship between MRI findings and the relative signal intensity of retrodiscal tissue in patients with temporomandibular joint disorders.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the relationship between magnetic resonance imaging (MRI) findings and the relative signal intensity (RSI) of retrodiscal tissue in patients with temporomandibular joint disorders (TMDs) and to determine the usefulness of RSI as a diagnostic marker.
  
  
  METHODS
  One hundred and thirty-two temporomandibular joints in 66 TMD patients were analyzed. The signal intensities of regions of interest (ROIs) in retrodiscal tissues were measured using T2-weighted MRI. The RSIs of retrodiscal tissues were referenced to the signal intensities of the ROIs of brain gray matter. The relationships between the RSI of retrodiscal tissue and condylar degenerative change (Wilcoxon rank sum test), joint effusion (Wilcoxon rank sum test), disc position (Kruskal-Wallis test), pain (Wilcoxon rank sum test), and limited mouth opening (Wilcoxon rank sum test) were determined.
  
  
  RESULTS
  A strong association was seen between retrodiscal-tissue RSI and disc displacement, joint effusion, condylar degenerative change, and joint pain. Limited mouth opening did not significantly correlate with retrodiscal-tissue RSI.
  
  
  CONCLUSIONS
  The retrodiscal-tissue RSI for T2-weighted MRI is a valuable noninvasive tool for monitoring the progression of TMD. Additional clinical studies are warranted.
authors.affiliation: Department of Oral and Maxillofacial Surgery, St. Mary's Hospital, the Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Sang-Hwa
authors.initials: SH
authors.lastname: Lee
authors.forename: Hyun-Joong
authors.initials: HJ
authors.lastname: Yoon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008335:Mandibular Condyle / Q000473:pathology; D008875:Middle Aged; D010003:Osteoarthritis / Q000473:pathology*; D012815:Signal Processing, Computer-Assisted; D013582:Synovial Fluid; D019224:Temporomandibular Joint Disc / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000473:pathology*; D055815:Young Adult