title: Correlation between the Pharyngeal Airway Space and Head Posture after Surgery for Mandibular Prognathism.
abstract: OBJECTIVE
  The aim of this study was to determine the correlation between the pharyngeal airway space and head posture after mandibular setback surgery for mandibular prognathism.
  
  
  METHODS
  Serial lateral cephalograms of 37 patients with mandibular prognathism who underwent intraoral vertical ramus osteotomy (IVRO) were evaluated before (T1) and immediately (T2), between 6 weeks and 3 months (T3), and more than 1 year (T4) after surgery. Paired t-tests and Pearson's correlation analysis were used to evaluate the postoperative changes in all cephalometric parameters, including the mandible, hyoid, head posture (craniocervical angle), and pharyngeal airway space.
  
  
  RESULTS
  The mandible and hyoid were set back by 12.8 mm and 4.9 mm, respectively, at T2. Furthermore, the hyoid showed significant inferior movement of 10.7 mm, with an 8 mm increase in the tongue depth. The upper oropharyngeal airway (UOP) shortened by 4.1 mm, the lower oropharyngeal airway (LOP) by 1.7 mm, and the laryngopharyngeal airway by 2 mm. The craniocervical angle showed a significant increase of 2.8°. UOP and LOP showed a significant correlation with the craniocervical angle at T2 and T4.
  
  
  CONCLUSIONS
  Our findings conclude that the oropharyngeal airway space is significantly decreased and correlated with a change in the head posture after mandibular setback surgery.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Chen
authors.affiliation: Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
authors.forename: Steven
authors.initials: S
authors.lastname: Lai
authors.affiliation: Department of Conservative Dentistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
authors.forename: Ker-Kong
authors.initials: KK
authors.lastname: Chen
authors.affiliation: Graduate Institute of Dental Sciences, College of Dental Medicine, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
authors.forename: Huey-Er
authors.initials: HE
authors.lastname: Lee
mesh_terms: D002508:Cephalometry; D005260:Female; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery*; D010614:Pharynx / Q000033:anatomy & histology*; D011182:Postoperative Care; D011187:Posture; D011378:Prognathism / Q000601:surgery*; D055815:Young Adult