title: Anterior tooth wear and retention type until 5 years after orthodontic treatment.
abstract: OBJECTIVE
  To study occlusal wear of anterior teeth in orthodontic patients retained with different retainers until 5 years post-treatment, and to investigate whether type of retention influences occlusal wear.
  
  
  METHODS
  Orthodontic patients (n=222), aged 15 years maximally at the start of treatment, were followed until 5 years post-treatment. In the maxilla, a retainer bonded on all six teeth or a removable retainer was used; in the mandible, a lingual retainer was bonded on all anterior teeth or on canines only. Dental casts were analyzed before treatment (T(0)), after treatment (T(1)), and 5 years post-treatment (T(5)). Incisal and canine wear were scored by applying a grading scale. Intercanine width, overjet, and overbite were measured with an electronic caliper. Statistics used were: Paired samples t-test for differences over time; Pearson correlation coefficients for associations between wear and retention type; and backward linear regression for influence of retention type on wear.
  
  
  RESULTS
  There was an increase in wear during all time periods and for all teeth. From T(0) to T(5) an increase in maxillary intercanine width and maxillary retention had an effect on changes in canine wear. Incisal wear was associated with an increase in upper intercanine width (T(1)-T(5)). For both arches, an increase in maxillary intercanine width during treatment was associated with less progression of canine and incisal wear, but the explained variance was low, 13.4% and 19.3%, respectively.
  
  
  CONCLUSIONS
  Retention type and, occasionally, an increase in intercanine width influence anterior teeth wear post-treatment. However, the clinical significance and impact of the examined retention methods on occlusal wear are small.
authors.affiliation: Department of Orthodontics, University of Geneva, Switzerland. mette.kuijpers@unige.ch
authors.forename: Mette A R
authors.initials: MA
authors.lastname: Kuijpers
authors.forename: Stavros
authors.initials: S
authors.lastname: Kiliaridis
authors.forename: Annemarie
authors.initials: A
authors.lastname: Renkema
authors.forename: Ewald M
authors.initials: EM
authors.lastname: Bronkhorst
authors.forename: Anne M
authors.initials: AM
authors.lastname: Kuijpers-Jagtman
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003481:Cuspid / Q000473:pathology*; D005260:Female; D006801:Humans; D007180:Incisor / Q000473:pathology*; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible; D008437:Maxilla; D009426:Netherlands / Q000453:epidemiology; D016382:Orthodontic Appliance Design / Q000009:adverse effects; D018704:Orthodontic Retainers / Q000009:adverse effects* / Q000145:classification; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014072:Tooth Abrasion / Q000453:epidemiology* / Q000473:pathology; D019217:Tooth Attrition / Q000453:epidemiology* / Q000473:pathology; D016896:Treatment Outcome; D055815:Young Adult