title: [The effect of extraction and non-extraction decompensation to bimaxillary orthognathic surgery in skeletal class III malocclusion].
abstract: OBJECTIVE
  To evaluate the effect of extraction and non-extraction decompensation to bimaxillary orthognathic surgery in skeletal class III malocclusion and the effect on postoperative.
  
  
  METHODS
  Records of 36 completed surgical-orthodontic treatment skeletal class III malocclusion patients were obtained from School of Stomatology, China Medical University, 18 underwent maxillary premolar extraction, the other 18 underwent non-extraction. Their post-decompensation and postsurgery cephalometric radiographs were analyzed objectively, and their profile scissors-shadows in different groups were evaluated subjectively.
  
  
  RESULTS
  The cephalometric index of post-presurgical orthodontics showed that there were significant deviations between the extraction and non-extraction groups including U1-SN, Overjet and Cm-Sn-UL values (P<0.05). During surgery, mandible was retruded (8.66 +/- 1.42) mm in extraction group compared with (6.21 +/- 3.06) mm in non-extraction group (P<0.05). After surgery, the extraction group achieved more normal ANB, U1-SN, NA-PA values (P>0.05).
  
  
  CONCLUSIONS
  Maxillary premolar extraction can make incisor decompensation more complete so that mandible can be retruded to more ideal position and concave face can be successfully corrected.
authors.affiliation: Dept. of Orthodontics, Stomatological Hospital of Dalian, Dalian 116021, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Xu
authors.forename: Ke
authors.initials: K
authors.lastname: Qin
mesh_terms: D001641:Bicuspid; D002508:Cephalometry; D005145:Face; D006801:Humans; D007180:Incisor; D008297:Male; D008313:Malocclusion, Angle Class III; D008334:Mandible; D057909:Orthognathic Surgery; D016896:Treatment Outcome