title: Three-dimensional upper-airway changes with maxillomandibular advancement for obstructive sleep apnea treatment.
abstract: BACKGROUND
  Airway size increases are associated with maxillomandibular advancement (MMA) surgery and improvement or elimination of obstructive sleep apnea (OSA). The 3-dimensional morphologic, volumetric, height, cross-sectional surface area, and diameter changes of the upper airway in patients with OSA after MMA, however, are not well understood.
  
  
  METHODS
  Patients with moderate or severe OSA who underwent MMA surgery were evaluated by preoperative and postoperative cone-beam computed tomography scans and polysomnograms. The upper airway space was also divided into retropalatal and retroglossal spaces and was analyzed for volumetric, height, cross-sectional surface area, transverse, and anteroposterior diameter changes.
  
  
  RESULTS
  Ten consecutive OSA patients with an average preoperative apnea/hypopnea index of 46 and treated with MMA surgery were included in this study. There were 8 men and 2 women, with an average age of 46 years and an average body mass index of 28. There was an average of a 2.5-fold increase in the total volume of the upper airway space. The retropalatal space increased by 3.5-fold. The retroglossal space increased by 1.5-fold. The greatest change in a cross-sectional area occurred in the transverse axis in both the retroglossal and retropalatal spaces. The average apnea/hypopnea index was 4 postoperatively.
  
  
  CONCLUSIONS
  MMA surgery results in a significant increase in the volume and a morphologic airway change from a round to an elliptical f shape in the upper airway space in patients with OSA. The combination of these actions reduces the collapsibility of the upper airway space, hence improving or resolving the OSA.
authors.affiliation: Emeritus professor, Department of Surgery; adjunct clinical professor, Department of Neurosurgery, Medical Center, Stanford University, Stanford, Calif. Electronic address: sschendel@stanford.edu.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Schendel
authors.affiliation: Private practice, Beverly Hills, Calif.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Broujerdi
authors.affiliation: Clinical instructor, Department of Orthodontics, School of Dentistry, University of California at Los Angeles, Pacific Palisades, Calif.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Jacobson
mesh_terms: D000328:Adult; D000368:Aged; D019412:Anatomy, Cross-Sectional; D015992:Body Mass Index; D002508:Cephalometry / Q000379:methods; D054893:Cone-Beam Computed Tomography / Q000379:methods; D004724:Endoscopy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D019186:Mandibular Advancement / Q000379:methods*; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D009929:Organ Size; D019340:Osteotomy, Le Fort / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods; D010159:Palate / Q000033:anatomy & histology; D010614:Pharynx / Q000033:anatomy & histology*; D017286:Polysomnography / Q000379:methods; D020181:Sleep Apnea, Obstructive / Q000601:surgery*; D014059:Tongue / Q000033:anatomy & histology