title: Unexpected complications of bonded mandibular lingual retainers.
abstract: BACKGROUND
  The flexible spiral wire (FSW) retainer is the most frequently used type of fixed retainer bonded on all 6 anterior teeth. Our aim in this article was to demonstrate unexpected posttreatment changes in the labiolingual position of the mandibular anterior teeth associated with the use of FSW retainers.
  
  
  METHODS
  During a 3-year period, patients attending the postgraduate orthodontic clinic of the Department of Orthodontics and Oral Biology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands, for regular, posttreatment follow-up appointments were screened for unexpected posttreatment changes in the mandibular anterior region.
  
  
  RESULTS
  Twenty-one patients with FSW retainers bonded on all 6 mandibular anterior teeth presented unexpected posttreatment changes in that region. Almost half of these patients were assessed as needing retreatment. Two patients are presented to illustrate the 2 distinct patterns of posttreatment changes: torque difference between 2 adjacent mandibular incisors and increased buccal inclination and movement of one mandibular canine.
  
  
  CONCLUSIONS
  FSW retainers bonded on the 6 mandibular anterior teeth might cause unexpected movements of anterior teeth to such an extent that retreatment is necessary. Clinicians should consider this possibility when planning the retention strategy.
authors: Department of Orthodontics and Oral Biology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. C.Katsaros@dent.umcn.nl
authors: Christos
authors: C
authors: Katsaros
authors: Christos
authors: C
authors: Livas
authors: Anne-Marie
authors: AM
authors: Renkema
mesh_terms: D000293:Adolescent; D003481:Cuspid / Q000503:physiopathology; D001840:Dental Bonding; D005260:Female; D006801:Humans; D007180:Incisor / Q000503:physiopathology; D008297:Male; D008334:Mandible; D016382:Orthodontic Appliance Design; D018704:Orthodontic Retainers / Q000009:adverse effects*; D019233:Retreatment; D014085:Tooth Migration / Q000209:etiology; D019415:Torque