title: The relationship between mouth opening and computerized tomographic features of posttraumatic bony ankylosis of the temporomandibular joint.
abstract: OBJECTIVE
  The purpose of this paper was to investigate the relationship between mouth opening and computerized tomography (CT) features in patients with bony ankylosis of the temporomandibular joint.
  
  
  METHODS
  A series of morphologic parameters-the diameters of bony mass (D1), the width of bony fusion area (D2), the ratio of D2/D1, and the degree of calcification in bony fusion area (D3)-were measured by Mimics 10.0 software. Correlation analysis and stepwise multiple linear regression analysis were the statistical methods used.
  
  
  RESULTS
  Nine patients (23.68%) with bony fusion area fully calcified were completely unable to open their mouth, whereas 29 patients (76.32%) with bony fusion area calcified incompletely had a slight degree of mouth opening. No correlation was found between mouth opening and D1. A negative correlation was observed between mouth opening and D2 (r = -0.670; P < .01), between mouth opening and D2/D1 (r = -0.697; P < .01), and between mouth opening and D3 (r = -0.744; P < .01). Multiple stepwise regression analysis identified D2 and D3 as predictive factors of residual mouth opening.
  
  
  CONCLUSIONS
  D2 and D3 were independent factors affecting the mouth opening. The insufficient calcification of bony fusion area, which cannot fully limit the motion of ankylosed joint, may be an important cause of residual mouth opening in patients with complete bony ankylosis.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Haidian District, Beijing, China.
authors.forename: Yingbin
authors.initials: Y
authors.lastname: Yan
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Sun
authors.forename: Jiangming
authors.initials: J
authors.lastname: Li
authors.forename: E
authors.initials: E
authors.lastname: Xiao
authors.forename: Jingang
authors.initials: J
authors.lastname: An
mesh_terms: D000293:Adolescent; D000328:Adult; D000844:Ankylosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015519:Bone Density / Q000502:physiology; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000503:physiopathology; D008875:Middle Aged; D009055:Mouth / Q000473:pathology; D016059:Range of Motion, Articular / Q000502:physiology*; D013701:Temporal Bone / Q000000981:diagnostic imaging / Q000503:physiopathology; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D036542:Tomography, Spiral Computed / Q000379:methods*; D055815:Young Adult