title: [A study on the module using pendulum combined with straight wire appliance in Angle class II and skeletal class I malocclusion].
abstract: OBJECTIVE
  To investigate morphologic changes of Angle class II and skeletal class I patients during pendulum and straight wire appliances treatment and to analyze the mechanism of this treatment protocol.
  
  
  METHODS
  10 patients with Angle class II and skeletal class I malocclusion were recruited. The lateral cephalometric radiographs were evaluated to determine if there were significant differences among pre-treatment (T1), after molar distalization (T2), and post-treatment (T3) variables including skeletal, dental and soft tissue relationships.
  
  
  RESULTS
  Differences between the T1 and T2 means were significant for distal movement and distal angulation of the maxillary molars (P < 0.01), mesial angulation of the maxillary incisors (P < 0.05), mesial movement of the maxilla (P < 0.01) . There were no significant changes between T1 and T3 in respect saggital position and angulation of the maxillary molars (P > 0.05) . Only the mesial movement of lower first molars and upper and lower jaws were significant (P < 0.01) during the whole treatment. No upper second molar impaction was detected after treatment.
  
  
  CONCLUSIONS
  The upper molars distalization could be achieved by pendulum appliance. The class I molar relationship could be obtained by the differential growth of jaws and the differential movement of upper and lower molars.
authors.affiliation: Dept. of Orthodontics, College and Hospital of Stomatology, Tongji University, Shanghai 200072, China.
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Zhao
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Liu
mesh_terms: D002508:Cephalometry; D006801:Humans; D007180:Incisor; D008311:Malocclusion, Angle Class I / Q000628:therapy*; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008334:Mandible; D008437:Maxilla; D008963:Molar; D009967:Orthodontic Appliances; D014087:Tooth Movement Techniques