title: Computational fluid dynamic analysis of the posterior airway space after maxillomandibular advancement for obstructive sleep apnea syndrome.
abstract: OBJECTIVE
  This study evaluated the soft tissue change of the upper airway after maxillomandibular advancement (MMA) using computational fluid dynamics.
  
  
  METHODS
  Eight patients with obstructive sleep apnea syndrome who required MMA were recruited into this study. All participants underwent pre- and postoperative computed tomography and then MMA by a single oral and maxillofacial surgeon. Upper airway computed tomographic datasets for these 8 patients were created with high-fidelity 3-dimensional numerical models for computational fluid dynamics. The 3-dimensional models were simulated and analyzed to study how changes in airway anatomy affect the pressure effort required for normal breathing. Airway dimensions, skeletal changes, apnea-hypopnea index, and pressure effort of pre- and postoperative 3-dimensional models were compared and correlations were interpreted.
  
  
  RESULTS
  After MMA, laminar and turbulent air flows were significantly decreased at every level of the airway. The cross-sectional areas at the soft palate and tongue base were significantly increased.
  
  
  CONCLUSIONS
  This study showed that MMA increased airway dimensions by increasing the distance from the occipital base to the pogonion. An increase of this distance showed a significant correlation with an improvement in the apnea-hypopnea index and a decreased pressure effort of the upper airway. Decreasing the pressure effort will decrease the breathing workload. This improves the condition of obstructive sleep apnea syndrome.
authors: Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA. jadesomsak@yahoo.com
authors: Somsak
authors: S
authors: Sittitavornwong
authors: Peter D
authors: PD
authors: Waite
authors: Alan M
authors: AM
authors: Shih
authors: Gary C
authors: GC
authors: Cheng
authors: Roy
authors: R
authors: Koomullil
authors: Yasushi
authors: Y
authors: Ito
authors: Joel K
authors: JK
authors: Cure
authors: Susan M
authors: SM
authors: Harding
authors: Mark
authors: M
authors: Litaker
mesh_terms: D000403:Airway Resistance; D002508:Cephalometry; D019295:Computational Biology / Q000379:methods*; D003198:Computer Simulation; D003799:Dental Stress Analysis; D006801:Humans; D057446:Hydrodynamics; D019186:Mandibular Advancement; D008437:Maxilla / Q000601:surgery*; D021362:Palate, Hard / Q000033:anatomy & histology; D010160:Palate, Soft / Q000033:anatomy & histology; D010614:Pharynx / Q000033:anatomy & histology*; D012123:Pulmonary Ventilation; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000601:surgery*; D014059:Tongue / Q000033:anatomy & histology; D014939:Work of Breathing
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