title: Accuracy of predicting the pharyngeal airway space on the cephalogram after mandibular setback surgery.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the accuracy of a formula predicting the change of pharyngeal airway space (PAS) on the cephalogram after mandibular setback surgery.
  
  
  METHODS
  Twenty-nine female adults with mandibular prognathism underwent surgery by bilateral sagittal split ramus osteotomy. The postoperative anteroposterior (A-P) PAS dimension was calculated from the change of C3-Me (distance between the anteroinferior point of the third cervical vertebra and menton) using 2 cephalograms taken before treatment and at 1 year after surgery. The regression equation used was y = -21.105 + 0.402x (y: PAS; x: C3-Me; r = 0.854).
  
  
  RESULTS
  The predicted and measured values were nearly same on average, and the difference between both ranged within +/-1.5 mm for each case individually.
  
  
  CONCLUSIONS
  This study suggested that the postoperative A-P PAS dimension can be predicted from the change in C3-Me, matching the amount of the mandibular setback.
authors.affiliation: Department of Oral & Maxillofacial Surgery, National Defense Medical College, Saitama, Japan. muto@ndmc.ac.jp
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Muto
authors.forename: Atsue
authors.initials: A
authors.lastname: Yamazaki
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Takeda
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sato
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000175:diagnosis; D000465:Algorithms; D002508:Cephalometry; D005260:Female; D006801:Humans; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D008334:Mandible / Q000002:abnormalities / Q000601:surgery*; D019647:Oral Surgical Procedures; D010027:Osteotomy; D010614:Pharynx / Q000033:anatomy & histology*; D011237:Predictive Value of Tests; D011378:Prognathism / Q000601:surgery; D012044:Regression Analysis