title: Natural Head Postures of Patients With Facial Asymmetry in Frontal View Are Corrected After Orthognathic Surgeries.
abstract: OBJECTIVE
  Although orthognathic surgeries focus on adjustment of facial asymmetry (FA), many clinicians know by experience that the natural head posture (NHP) also is corrected after the surgery. The authors examined whether this was indeed the case by the measuring the NHP during the course of orthognathic treatment. Factors associated with NHP correction also were evaluated.
  
  
  METHODS
  In this retrospective study, clinical features, including the NHP, of patients with FA and those with facial symmetry (FS) were compared. They were outpatients of a private orthodontic dental clinic from December 2008 to March 2012. The degree of NHP tilt was evaluated using an interpupillary (IP) horizontal angle. The NHP of patients with FA were analyzed further before presurgical orthodontic treatment, after presurgical orthodontic treatment, after orthognathic surgery and postsurgical orthodontic treatment, and 1 year after completion of postsurgical orthodontic treatment. The NHP difference at each time point was analyzed using 1-way analysis of variance. An analysis of factors that influence NHP tilt correction was performed by linear regression.
  
  
  RESULTS
  Thirty-one patients with FA and 27 with FS were evaluated. The NHP tilt was more profound in the FA group compared with the FS group. There were more patients with skeletal Class III in the FA group. The degree of NHP tilt in the FA group was decreased after orthognathic surgery and postsurgical orthodontic treatment and remained when measured 1 year later. Women were less prone than men to NHP tilt correction by orthognathic surgery.
  
  
  CONCLUSIONS
  Patients with FA have a tilted NHP compared with those with FS. Orthognathic surgery for FA might correct a tilted NHP to a lesser degree in women.
authors.affiliation: Clinical Assistant Professor, Division of Oral and Maxillofacial Surgery, Department of Dentistry, St Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea.
authors.forename: Ji-Youn
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Vice Director, FOS (Face and Oral Surgery) Clinic, Seoul, Korea.
authors.forename: Moon-Ho
authors.initials: MH
authors.lastname: Kang
authors.affiliation: Director, Gnatho Orthognathic Surgery Clinic, Seoul, Korea.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: You
authors.affiliation: Research Scientist, Research Institute, National Medical Center, Seoul, Korea.
authors.forename: Hyeon-Gun
authors.initials: HG
authors.lastname: Jee
authors.affiliation: Clinical Fellow, Department of Endocrine Surgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Yi
authors.affiliation: Director, Smilefuture Orthodontic Clinic; Adjunct Professor, Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea. Electronic address: orthodont@naver.com.
authors.forename: Byoung-Ho
authors.initials: BH
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005145:Face / Q000033:anatomy & histology; D005146:Facial Asymmetry / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D063172:Genioplasty / Q000379:methods; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008313:Malocclusion, Angle Class III / Q000473:pathology / Q000601:surgery; D009971:Orthodontics, Corrective / Q000379:methods; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D019340:Osteotomy, Le Fort / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods; D010781:Photography / Q000379:methods; D011187:Posture; D012189:Retrospective Studies; D012737:Sex Factors; D016037:Single-Blind Method; D055815:Young Adult