title: Assessment of articular disc displacement of temporomandibular joint with ultrasound.
abstract: OBJECTIVE
  To assess pattern of articular disc displacement in patients with internal derangement (ID) of temporomandibular joint (TMJ) with ultrasound.
  
  
  METHODS
  Prospective study was conducted upon 40 TMJ of 20 patients (3 male, 17 female with mean age of 26.1 years) with ID of TMJ. They underwent high-resolution ultrasound and MR imaging of TMJ. The MR images were used as the gold standard for calculating sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of ultrasound for diagnosis of anterior or sideway displacement of the disc.
  
  
  RESULTS
  The anterior displaced disc was seen in 26 joints at MR and 22 joints at ultrasound. The diagnostic efficacy of ultrasound for anterior displacement has sensitivity of 79.3 %, specificity of 72.7 %, accuracy of 77.5 %, PPV of 88.5 %, NPV of 57.1 %, PLR of 2.9 and NLR of 0.34. The sideway displacement of disc was seen in four joints at MR and three joints at ultrasound. The diagnostic efficacy of ultrasound for sideway displacement has a sensitivity of 75 %, specificity of 63.6 %, accuracy of 66.7 %, PPV of 42.8, NPV of 87.5 %, PLR of 2.06, and NLR of 0.39.
  
  
  CONCLUSIONS
  We concluded that ultrasound is a non-invasive imaging modality used for assessment of anterior and sideway displacement of the articular disc in patients with ID of TMJ.
authors.affiliation: Department of Diagnostic Radiology, Mansoura Faculty of Medicine, Mansoura, 13351 Egypt.
authors.forename: Ahmed Abdel Khalek Abdel
authors.initials: AA
authors.lastname: Razek
authors.affiliation: Department of Oral and Maxillofacial Surgery, Mansoura Faculty of Dentistry, Mansoura, Egypt.
authors.forename: Fouad
authors.initials: F
authors.lastname: Al Mahdy Al Belasy
authors.affiliation: Department of Oral and Maxillofacial Surgery, Mansoura Faculty of Dentistry, Mansoura, Egypt.
authors.forename: Wael Mohamed Said
authors.initials: WM
authors.lastname: Ahmed
authors.affiliation: Department of Oral and Maxillofacial Surgery, Mansoura Faculty of Dentistry, Mansoura, Egypt.
authors.forename: Mai Ahmed
authors.initials: MA
authors.lastname: Haggag
keywords: Disc; Displacement; Temporomandibular; Ultrasound