title: [Radiographic study on the efficacy of mandibular advancement in patients with obstructive sleep apnea syndrome].
abstract: OBJECTIVE
  To investigate the efficacy and mechanism of mandibular advancement device (MAD) treatment on obstructive sleep apnea syndrome (OSAS) patients.
  
  
  METHODS
  Eighty OSAS patients treated with a mandibular protraction appliance were included in the study. Three-dimensional reconstruction technique was used as to measure the changes of upper airway structure and volume before and after MAD treatment. The data was analyzed using SPSS 17.0 software package.
  
  
  RESULTS
  The anatomic structure and the reinforcement of soft tissue's collapse in the upper airway changed after application of MAD in OSAS patients; velopharyngeal and laryngopharynx configuration was significantly increased (P<0.01), while oropharyngeal configuration was significantly decreased (P<0.05).
  
  
  CONCLUSIONS
  This study demonstrated that pathogeny of OSAS based on morphological characteristics may be removed by mandibular advancement device, the mechanism of efficacy of MAD treatment can be the reduction of airway internal fluctuation and vortex of air.
authors.affiliation: Department of Stomatology, Yan'an Hospital of Kunming City. Kunming 650051,Yunnan Province, China. E-mail:zhaojunjun@msn.com.
authors.forename: De-hong
authors.initials: DH
authors.lastname: Li
authors.forename: Xiang-hong
authors.initials: XH
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.forename: Ling-peng
authors.initials: LP
authors.lastname: Zhang
authors.forename: Wen
authors.initials: W
authors.lastname: Shu
mesh_terms: D006801:Humans; D008334:Mandible / Q000000981:diagnostic imaging*; D019186:Mandibular Advancement; D017286:Polysomnography; D011859:Radiography; D020181:Sleep Apnea, Obstructive