title: Evaluation of posttreatment stability after orthodontic treatment in the mixed and permanent dentitions.
abstract: OBJECTIVE
  To investigate posttreatment changes in the maxillary and mandibular arches in patients who underwent orthodontic treatment during the mixed and permanent dentitions.
  
  
  METHODS
  The sample was collected retrospectively from three private practices and consisted of 42 patients who were at least 10 years out of orthodontic treatment. The longitudinal records of study casts and cephalometric radiographs were analyzed to quantify posttreatment changes.
  
  
  RESULTS
  Minimal changes in maxillary and mandibular irregularity occurred after an average of 16.98 years from completion of treatment. More than 10 years posttreatment, approximately 81% of the maxillary anterior teeth and 88% of the mandibular anterior teeth showed clinically acceptable incisor alignment (<3.5 mm). Mandibular fixed retainers greatly aided in maintaining the stability of the mandibular incisor alignment. However, posttreatment changes in maxillary incisor irregularity did not appear to be influenced by the presence of a mandibular fixed retainer. When compared with longitudinal changes observed in untreated subjects, the increase in incisor irregularity resembled a pattern similar to the regression line of untreated subjects and seems to be entirely age related. Arch width and arch depth was consistently decreased after treatment, but the magnitude of change was minimal at about 1 mm. No associations were found between any of the cephalometric measurements and changes in incisor irregularities.
  
  
  CONCLUSIONS
  Orthodontic treatment stability can be achieved and mandibular fixed retention appears to be a valuable contributor, especially in patients with further growth expected.
authors.forename: Heesoo
authors.initials: H
authors.lastname: Oh
authors.forename: Ning
authors.initials: N
authors.lastname: Ma
authors.forename: Ping Ping
authors.initials: PP
authors.lastname: Feng
authors.forename: Katherine
authors.initials: K
authors.lastname: Kieu
authors.forename: Roger
authors.initials: R
authors.lastname: Boero
authors.forename: Steven
authors.initials: S
authors.lastname: Dugoni
authors.forename: Maryse
authors.initials: M
authors.lastname: Aubert
authors.forename: Dave
authors.initials: D
authors.lastname: Chambers
mesh_terms: D000328:Adult; D002508:Cephalometry; D003724:Dental Arch; D019229:Dentition, Permanent; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor; D008297:Male; D008310:Malocclusion; D008334:Mandible; D008437:Maxilla; D009967:Orthodontic Appliances; D012008:Recurrence; D055815:Young Adult
keywords: Incisor irregularity; Long-term stability; Mandibular fixed retainer; Posttreatment; Retention