Title Patient Compliance and Satisfaction Is Greater with Vacuum Formed Retainers (VFR) Than With Hawley Retainers for 2 Years Following Completion of Orthodontic Therapy
Clinical Question Following orthodontic treatment, are patients more compliant in wearing vacuum-formed retainers compared to conventional (Hawley) retainers?
Clinical Bottom Line Patient compliance and satisfaction is greater with VFRs than Hawley retainers for 2 years following completion of orthodontic therapy; however, overall patient compliance is greater with Hawley retainers. Higher patient compliance with VFRs at 3 months, 6 months, and up to 2 years is supported by three independent studies including a randomized control trial, a cross sectional study, and a cohort study. The cross sectional study showed compliance with VFRs decreased much faster than with Hawley retainers, resulting in greater compliance at any time over 2 years, as well as greater overall compliance, with the Hawley retainer.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
27504404Mirzakouchaki/201677 Orthodontic patients ages 7-11Cohort study
Key resultsThe type of retainer significantly affected mean wear hours per day (p=0.01), which was significantly greater in VFRs than Hawley retainers. The mean wear time was 17.2 for VFRs and 13.8 for Hawleys with a SD of 6.3 and 5.5 respectively.
21803257Pratt/2011280 Patients who completed full orthodontics fixed appliance therapy at the University of Kentucky Cross-Sectional Study
Key resultsA logistic regression model identified age, sex, amount of time out of braces, retainer type, and patient interpretation of proper retainer compliance as significant variables influencing compliance (chi-square, 124.0485; dt, 11 abbreviations).
17702797Hichens/2007397 patients treated by one dentist due to have their fixed orthodontic appliances removedRandomized Controlled Trial
Key resultsPatients in the VFR group wore retainers more than the Hawley group (84.9% compliance with Hawley and 95% compliance with VFR; P= 0.002). Patients in the VFR group gave a more favorable rating of their retainers compared to fixed appliances (43.1% with Hawley and 81% with VFR; P < 0.001).
Evidence Search ("patient compliance"[MeSH Terms] OR ("patient"[All Fields] AND "compliance"[All Fields]) OR "patient compliance"[All Fields]) AND ("orthodontic retainers"[MeSH Terms] OR ("orthodontic"[All Fields] AND "retainers"[All Fields]) OR "orthodontic retainers"[All Fields] OR ("orthodontic"[All Fields] AND "retainer"[All Fields]) OR "orthodontic retainer"[All Fields])
Comments on
The Evidence
Validity: Both the Mirzakouchaki and Hichens studies followed patient groups that were similar prior to treatment and followed their patients through treatment. The study by Pratt used follow-up questionnaires mailed to patients who had already completed orthodontic treatment within the last 6 years, so the patient groups were not similar at the beginning. Mirzakouchaki had over 90% completion, Hichens had 89% completion, and Pratt had 25.8% of patients responding. Mirzakouchaki followed patients for 3 months. None of the three studies were double blinded. All three were subject to recall bias since they all relied on patient recall and questionnaires. The study by Mirzakouchaki included patients of the university as well as his own private practice. This could be seen as a conflict of interest. However, the study design was independently reviewed and approved by the Committee for Research Ethics at the Tabriz University of Medical Sciences. The other two studies reported no conflicts of interest. Perspective: All three of the studies were based on questionnaires. Hichens tested the questionnaires on patients for reproducibility and accuracy. However, Mirzakouchaki and Pratt did not. There may have been difference in interpretation of the questionnaire by patients which could affect reported results. Additionally, the only study that evaluated long term results was Pratt. Because orthodontic patients are instructed to continue wearing retainers long term, the other two studies should have followed patients for longer than 3 and 6 months to evaluate how compliance may change.
Applicability All three studies were applicable to patients who would normally be seen in an orthodontic practice. The study conducted by Pratt included patients ranging from 8 to 72 years old. The other two studies focused mostly on adolescents. Since the majority of orthodontic treatment occurs in adolescents this is applicable to the representative population. Since the study by Pratt only included patients of the University of Kentucky, the study by Hichens included only one private practice, and the study by Mirzakouchaki included both private practice and patients at the university, there is likely difference in demographics and socioeconomic status that may affect results. All the studies evaluated Hawley and VFRs as post-treatment retainers. These are the most widely used and accepted. All three studies looked at multiple factors affecting patient compliance and were able to pinpoint factors that were important in predicting compliance, thus allowing practitioners to identify methods to increase compliance based on their own patient population.
Specialty (General Dentistry) (Orthodontics)
Keywords Hawley retainers, vacuum-formed retainers, patient compliance, patient satisfaction, orthodontic retainers
ID# 3243
Date of submission 04/21/2017
E-mail xieL@livemail.uthscsa.edu
Author Lynn Xie
Co-author(s) e-mail
Faculty mentor Peter Gakunga, DDS, MS, PhD
Faculty mentor e-mail GAKUNGA@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available