Authors' response.

[1]  D. Koletsi,et al.  Objective evaluation of compliance after orthodontic treatment using Hawley or vacuum-formed retainers: A 2-center randomized controlled trial over a 3-month period. , 2019, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[2]  Onur Kadioglu,et al.  Evaluation of 3 retention protocols using the American Board of Orthodontics cast and radiograph evaluation. , 2013, American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics.

[3]  H. Worthington,et al.  Retention procedures for stabilising tooth position after treatment with orthodontic braces. , 2004, The Cochrane database of systematic reviews.

[4]  Birgit Thilandera.  Orthodontic relapse versus natural development , 2000 .

[5]  K. Reitan,et al.  Principles of retention and avoidance of posttreatment relapse. , 1969, American journal of orthodontics.