title: Does the Pharyngeal Airway Recover After Sagittal Split Ramus Osteotomy for Mandibular Prognathism?
abstract: OBJECTIVE
  Mandibular setback surgery can adversely affect the pharyngeal airway. The aim of this study was to investigate changes of the pharyngeal airway at specific intervals during a 12-month period after bilateral sagittal split ramus osteotomy (BSSO) for correction of mandibular prognathism.
  
  
  METHODS
  This retrospective cohort study included patients with mandibular prognathism who underwent BSSO. The pharyngeal airway was measured at 3 different levels on lateral cephalograms: the uvula tip, the most inferior-anterior point on the body of the second cervical vertebra (low-C II), and a midanterior point on the body of the third cervical vertebra (mid-C III). The pharyngeal airway was measured preoperatively, immediately postoperatively, and 1, 3, 6, and 12 months postoperatively. The measurements at each level were compared. Multivariable analysis of variance was used to measure the changes in pharyngeal airway space over time.
  
  
  RESULTS
  The study sample was composed of 30 patients (14 men and 16 women) who were diagnosed with mandibular prognathism. The pharyngeal airway at the uvular tip level was significantly reduced by 39% (P < .001) after surgery and was significantly improved by 26% (P < .01) from baseline at 1 month postoperatively. The pharyngeal airway at the low-C II level was significantly reduced by 27% (P < .001) after surgery and was significantly improved by 24% (P < .01) from baseline at 1 month postoperatively. The pharyngeal airway at the mid-C III level was significantly reduced by 23% (P < .001) after surgery and was improved by only 13% from baseline at 1 month postoperatively. Additional statistical changes were not noted on 3 and 6 months postoperative radiographs at all levels. The pharyngeal airway was decreased by 16, 19, and 8% from baseline at 12 months postoperatively, respectively. The upper airway length was significantly increased immediately after surgery (P < .001), but was incompletely recovered at 12 months postoperatively.
  
  
  CONCLUSIONS
  The outcomes of this study indicate that the pharyngeal airway gradually recovers over time. An immediate postoperative reduction in pharyngeal airway space can induce or exacerbate obstructive sleep apnea symptoms; thus, any pre-existing symptoms should be screened and considered for surgical treatment planning.
authors.affiliation: Clinical Lecturer, Department of Dentistry/Oral and Maxillofacial Surgery, College of Medicine, Hanyang University, Seoul, Korea.
authors.forename: Jae-Yun
authors.initials: JY
authors.lastname: Jeon
authors.affiliation: PhD Candidate, Department of Dentistry/Oral and Maxillofacial Surgery, College of Medicine, Hanyang University, Seoul; Private Practice, Gimpo, Gyeonggi, Korea.
authors.forename: Tae-Sun
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Former Chief Resident, Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Harvard Medical School, Boston; Private Practice, Vienna, VA.
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Associate Professor, Department of Dentistry/Oral and Maxillofacial Surgery, College of Medicine, Hanyang University, Seoul, Korea.
authors.forename: Chang-Joo
authors.initials: CJ
authors.lastname: Park
authors.affiliation: Professor, Department of Dentistry/Oral and Maxillofacial Surgery, College of Medicine, Hanyang University, Seoul, Korea. Electronic address: hkg@hanyang.ac.kr.
authors.forename: Kyung-Gyun
authors.initials: KG
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D000328:Adult; D059925:Anatomic Landmarks / Q000033:anatomy & histology; D001368:Axis, Cervical Vertebra / Q000033:anatomy & histology; D002508:Cephalometry / Q000379:methods; D002574:Cervical Vertebrae / Q000033:anatomy & histology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D010614:Pharynx / Q000033:anatomy & histology*; D011378:Prognathism / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014609:Uvula / Q000033:anatomy & histology; D055815:Young Adult