title: A feasible method to improve adherence of Hawley retainer in adolescent orthodontic patients: a randomized controlled trial.
abstract: BACKGROUND
  Retention is an important component of orthodontic treatment; however, poor compliance with retainer use is often encountered, especially in adolescents. The purpose of this study was to prove the hypothesis that verbal instructions combined with images showing the severe consequences of poor compliance can increase retainer use.
  
  
  METHODS
  This study was a randomized controlled trial. The sample was recruited from Wenzhou, People's Republic of China, between February 2013 and May 2014, and 326 participants were randomized into three groups. Patients and parents in Group A (n=106) were given routine retainer wear instructions only; in Group B (n=111), images illustrating the severe consequences of poor compliance with Hawley retainer use were shown to patients, combined with routine instructions; and in Group C (n=109), images illustrating the severe consequences of poor compliance with Hawley retainer use were shown to patients and parents, combined with routine instructions. Three months after debonding, questionnaires were used to investigate daily wear time and the reasons for poor compliance. Differences in means between the groups were tested by one-way analysis of variance.
  
  
  RESULTS
  The mean daily wear time in Group C (15.09±4.13 hours) was significantly greater than in Group A (12.37±4.58 hours, P<0.01) or Group B (13.50±4.22 hours, P<0.05); the mean daily wear time in Group B was greater than in Group A, but was not significant (P=0.67). Reasons for nonusage were forgetting to wear the retainer (51%) and finding the retainer bothersome to frequently insert and remove (42%).
  
  
  CONCLUSIONS
  Verbal instructions combined with images showing the severe consequences of poor compliance can increase retainer use. Parents play an important role in compliance with retainer use in adolescent patients.
authors.affiliation: Orthodontic Department, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Feiou
authors.initials: F
authors.lastname: Lin
authors.affiliation: Orthodontic Department, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.affiliation: Orthodontic Department, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Ni
authors.affiliation: Orthodontic Department, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Minling
authors.initials: M
authors.lastname: Zheng
authors.affiliation: Pedodontic Department, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China.
authors.forename: Linjie
authors.initials: L
authors.lastname: Yao
keywords: Hawley retainers; adherence; orthodontics