title: [Study on the characteristics and reasons for mistakes in some orthodontic cases].
abstract: OBJECTIVE
  To evaluate the characteristics and reasons for mistakes in some orthodontic cases.
  
  
  METHODS
  37 cases after or during treatment in other hospitals with mis-treatment were chosen, their original records as well as the records when they came to our hospital were collected, their original and present malocclusions were classified and the characteristics and reason of mistakes were analysed.
  
  
  RESULTS
  Among the 37 cases, 26 cases had class-III malocclusion which account for 70.27% of the group, especially for the malocclusions began in mixed dentition and the problems developed from anterior dental crossbite to severe skeletal crossbite with dentofacial asymmetry and openbite. The main reasons lie in the mistakes of diagnosis and treatment planning, preventive treatment,appliance fabrication,use of extraoral arch and elastics, treatment processes, et al.
  
  
  CONCLUSIONS
  There are various characteristics and reasons of treatment mistakes, but the problems lie mainly in class-III malocclusion especially during mixed dentition which indicates that we should pay more attention to the treatment of class-III malocclusion.
authors.affiliation: Orthodontic Department, Stomatological Hospital, China Medical University, Shenyang 110002, liaoning province, China. drqinke@sina.com
authors.forename: Ke
authors.initials: K
authors.lastname: Qin
authors.forename: Xin
authors.initials: X
authors.lastname: Chang
authors.forename: Zhen-Jin
authors.initials: ZJ
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D009971:Orthodontics, Corrective; D017211:Treatment Failure