title: [The effect of modified Nance arch on treating maxillary impacted canine transposed with first premolar].
abstract: OBJECTIVE
  To explore the effect of modified Nance arch on treating maxillary canine-first premolar transposition cases, in which the anchorage and force direction were discussed.
  
  
  METHODS
  Modified Nance arch was applied to 5 cases with maxillary impacted canine-first premolar transposition. First, a lingual knot button was bonded on the surface of the canine crown. Modified Nance arch was decorated with a hook that moved horizontally and buccally. Then the location of the hook was gradually adjusted in order to move the canine cross the root of the first premolar and move the canine to the right position. At last the canine was moved downward by straight wire appliance.
  
  
  RESULTS
  Five maxillary transposed canines were fully erupted in their right position, with normal pulp activity and gingival morphology. No obvious root resorption was detected. The mean treatment time was 30 months.
  
  
  CONCLUSIONS
  Modified Nance arch has advantages in treating canine-first premolar transposition.
authors.affiliation: Department of Orthodontics, Stomatological Hospital, Wenzhou Medical University. Wenzhou 325027; China. E-mail:marklovezl@163.com.
authors.forename: Qing-chao
authors.initials: QC
authors.lastname: Xu
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: Xiu-ying
authors.initials: XY
authors.lastname: Wang
authors.forename: Rong-dang
authors.initials: RD
authors.lastname: Hu
mesh_terms: D001641:Bicuspid; D003481:Cuspid; D003724:Dental Arch; D006801:Humans; D008437:Maxilla; D009967:Orthodontic Appliances; D012391:Root Resorption; D014078:Tooth Eruption; D014092:Tooth Root; D014095:Tooth, Impacted / Q000628:therapy*