title: Magnetic resonance images of the temporomandibular joints of patients with acquired open bite.
abstract: OBJECTIVE
  Acquired anterior open bites were reported as the consequence of condylar collapse, which was associated with inflammatory TMJ disorders. However, we have seen such malocclusion patients whose condylar changes seemed to be related to TMJ degeneration associated with internal derangement. The aims of this study were to review the clinical history and to study the TMJ MRI of these patients.
  
  
  METHODS
  TMJ MRIs of patients, who had presented acquired anterior open bite at first visit, were retrieved from the image database for the analysis. Clinical histories focused on internal derangement were collected retrospectively. The soft tissue and hard tissue changes disclosed by MRI were also studied.
  
  
  RESULTS
  All patients had experienced common signs/symptoms of TMJ internal derangement. All affected TMJs had anteriorly displaced disks and degenerative changes. Horizontally destructed condylar forms were seen significantly more frequently in these patients.
  
  
  CONCLUSIONS
  TMJ degeneration associated with displaced disks might be a cause leading to the development of acquired anterior open bite.
authors.affiliation: School of Dentistry, National Taiwan University, Medical College and Hospital, Taipei, Taiwan. chenyj@ha.mc.ntu.edu.tw <chenyj@ha.mc.ntu.edu.tw>
authors.forename: Yunn-Jy
authors.initials: YJ
authors.lastname: Chen
authors.forename: Tiffany Ting-Fang
authors.initials: TT
authors.lastname: Shih
authors.forename: Juo-Song
authors.initials: JS
authors.lastname: Wang
authors.forename: Huey-Yuan
authors.initials: HY
authors.lastname: Wang
authors.forename: Yuh-Yuan
authors.initials: YY
authors.lastname: Shiau
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000150:complications / Q000473:pathology; D008279:Magnetic Resonance Imaging; D017090:Occlusal Splints; D024343:Open Bite / Q000209:etiology* / Q000473:pathology; D010003:Osteoarthritis / Q000150:complications* / Q000473:pathology; D012189:Retrospective Studies; D013704:Temporomandibular Joint / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000150:complications* / Q000473:pathology