title: Three-Dimensional Computed Tomographic Assessment of Temporomandibular Joint Stability After Orthognathic Surgery.
abstract: OBJECTIVE
  Ensuring that the condyle is appropriately positioned and that positional changes are minimal is considered crucial for the temporomandibular joint (TMJ) to function without symptoms after orthognathic surgery. The purposes of this study were to evaluate condylar changes after surgery and to examine the association between these changes and TMJ symptoms.
  
  
  METHODS
  A retrospective cohort study was conducted in patients with mandibular prognathism who underwent orthognathic surgery. Linear and angular changes in the positioning of the condyle were measured by superimposing 3-dimensional computed tomograms taken before surgery and 3 months after surgery. Clinical symptoms of TMJ pain and sound were recorded at 3, 6, 9, and 12 months after surgery. Possible associations between TMJ symptoms and clinical variables, such as postoperative condylar changes, were investigated using multiple logistic regression analysis.
  
  
  RESULTS
  Linear condylar displacement after orthognathic surgery occurred predominantly in the anterior, medial, and inferior directions, with minimal changes (<1 mm) observed. Most angular condylar changes were smaller than 4° and occurred in the inward direction in the axial plane and the posterior direction in the sagittal plane. The best predictor of postoperative TMJ signs and symptoms was the preoperative status of TMJ signs and symptoms. Neither linear nor angular condylar displacement showed a relevant influence on postoperative pain and sound.
  
  
  CONCLUSIONS
  Within the ranges of linear (<1 mm) and angular (<4°) condylar displacement noted in this study, displacement was not associated with postoperative TMJ pain and sound.
authors.affiliation: Clinical Professor, Department of Oral and Maxillofacial Surgery, Section of Dentistry, Seoul Metropolitan Government - Seoul National University Boramae Medical Center, Seoul, Korea.
authors.forename: Yoon-Sic
authors.initials: YS
authors.lastname: Han
authors.affiliation: PhD Student, Department of Oral and Maxillofacial Surgery, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Korea.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Jung
authors.affiliation: Clinical Assistant Professor, Department of Oral and Maxillofacial Surgery, Korea University Anam Hospital, Seoul, Korea.
authors.forename: In-Seok
authors.initials: IS
authors.lastname: Song
authors.affiliation: Professor, Department of Orthodontics, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Korea.
authors.forename: Shin-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, Seoul National University School of Dentistry and Dental Research Institute, Seoul, Korea. Electronic address: seobm@snu.ac.kr.
authors.forename: Byoung Moo
authors.initials: BM
authors.lastname: Seo
mesh_terms: D000293:Adolescent; D000328:Adult; D005146:Facial Asymmetry / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007593:Joint Instability / Q000000981:diagnostic imaging*; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging* / Q000601:surgery*; D056948:Orthognathic Surgical Procedures; D010149:Postoperative Pain / Q000000981:diagnostic imaging; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011378:Prognathism / Q000000981:diagnostic imaging* / Q000601:surgery*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed