Introduction
Long-term follow-up and management of orthodontic bonded retainers require a strong collaboration between orthodontists and general dental practitioners (GDPs). This study aimed to evaluate if Eastern French GDPs were aware of bonded retainers’ complications and side effects and if they were willing to take part in their long-term follow-up.
Methods
Two-hundred and eighteen randomly selected GDPs were invited to answer an online questionnaire. The initial sections covered their experience and management with bonded retainers. In the final sections, GDPs were asked their opinion on the responsibility for long-term follow-up of patients wearing fixed retainers and on the mutual communication between orthodontists and GDPs. Statistical analysis involved descriptive statistics and Fisher exact tests.
Results
Response rate was 32.6% (n = 71). The vast majority of GDPs were familiar with loose retainers, but only 45.2% were willing to repair them. Respondents offering orthodontic services on a regular basis were more likely to insert retainers and repair loose or broken retainers ( P < 0.001). Approximately 18.6% of GDPs were aware of third-order side effects encountered with unintentionally active retainers bonded to all 6 anterior teeth. For 88.8% of GDPs, permanent retention was justified, whereas 90% of the dentists refused to be responsible for long-term supervision of fixed retainers. In addition, 67.1% were interested in further training on orthodontic retention, and 92.9% would appreciate clinical guidelines.
Conclusions
Knowledge about the harmful side effects of bonded retainers was evaluated as insufficient among surveyed GDPs. Long-term follow-up of patients wearing bonded retainers raises issues that should be addressed globally by enhancing mutual communication, practitioners’ education, and patients’ involvement.
Highlights
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General dentists were unaware of unwanted third-order movements caused by bonded retainers.
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Approximately 67% of dentists are interested in continuing education on orthodontic retention.
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Dentists do not believe they are well-informed on the retention phase by their orthodontist peers.
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Billing issues limit dentists’ desire to supervise bonded retainers in the long term.
Bonded retainers are frequently used to prevent relapse of anterior crowding after orthodontic treatment. They are effective in maintaining alignment of maxillary and mandibular anterior teeth. Two basic designs are used in the mandibular arch: either a rigid wire bonded to canines only or a retainer bonded to all anterior teeth. , The latter is more effective in preventing incisor irregularity, , , and is usually made of plain or multistrand stainless steel wires of various cross-sections. ,
Currently, 65%-92% of orthodontists in European countries or the United States do not recommend the removal of bonded retainers for long-term maintenance of treatment results. , This recommendation is most likely made to keep the anterior teeth alignment, which is strongly associated with posttreatment patient satisfaction. However, complications such as wire fractures or bond failures occur in some instances, with failure rates reaching up to 50%. Moreover, bonded retainers have been reported to become unintentionally active in some patients, resulting in opposite buccolingual inclinations of adjacent teeth (X effect) or opposite canines (twist effect). , These unexpected movements would affect 1.1%-5% of patients wearing fixed retainers. , , Some of these complications can be severe enough to require retreatment and might be associated with irreversible periodontal damages. , ,
Regular retention check-ups are therefore necessary as long as bonded retainers remain in place. This increases the number of patients under supervision as well as the workload in orthodontic practices. , The initial retention follow-up is usually performed by the orthodontist during the first 1-3 years in retention. , , However, attendance of patients at retention check-ups, decreases with time, and general dental practitioners (GDPs) could take over the long-term supervision and management of bonded retainers at annual appointments. This would be more convenient for the patients and would free them from attending their orthodontist’s practice. Even if this procedure has been recommended in recent guidelines, , little is known about the perception GDPs have of this transfer of responsibility or their ability to perform this long-term maintenance. Previous studies in Switzerland (2012) and the United Kingdom (2014) highlighted issues regarding communication between orthodontists and dentists and insufficient knowledge of potential side effects with bonded retainers among GDPs. , GDPs’ willingness to monitor bonded retainers was different between these nations. It is therefore timely and appropriate to conduct similar surveys in other countries to have a broader perspective on this question.
This study aimed to determine Eastern French GDPs’ management of orthodontic bonded retainers, knowledge of their side effects, and to evaluate their willingness to take part in their long-term follow-up. GDPs’ perceptions of permanent retention and their demand regarding specific training on fixed retainers were also assessed.
Material and methods
This survey was approved by the Ethics Review Board of the Faculty of Dental Surgery and the University Hospitals of Strasbourg, France.
On the basis of sample size calculation, 218 GDPs were randomly selected among the 1433 dentists practicing in Alsace, Eastern France, to obtain a 95% confidence level with a 6% margin of error. The names of the 1433 registered dentists were collected from the French Dental Board and randomized using the RAND function in Excel (Microsoft™, Redmond Wash).
The questionnaire was adapted for French working conditions from the one used in a previous study of Swiss GDPs’ management of orthodontic retainers. The latter was already available in French. Therefore, the adapted version was prepiloted and validated by staff members not involved in the study without the need to renew a pilot study. The questionnaire was organized into 4 parts: (1) the first gathered demographic information (gender, age, working experience, and type of practice), (2) the second section dealt with dentists’ clinical management of bonded retainers, (3) the third part aimed to evaluate GDPs’ knowledge of bonded retainers’ side effects, and (4) the final part focused on communication between dentists and orthodontists on the retention follow-up, the responsibility of long-term supervision and the need for common guidelines.
In May 2019, the selected GDPs were contacted and asked to anonymously answer the online questionnaire. Data collection was stopped by the end of June after 2 reminders: 1 and 3 weeks after the initial e-mail. Participants could only complete the questionnaire once. All investigators were blinded to the names of the respondents.
Statistical analysis
Statistical analysis involved descriptive statistics presented as absolute values and percentages. Associations between items in the questionnaire with the working experience of the practitioner and the provision of orthodontic services were evaluated with Fisher exact tests. The level of significance was set at 5%. All statistical analyses were performed with the R Program (version 3.4.3; R Foundation for Statistical Computing, Vienna, Austria).
Results
A total of 71 out of 218 GDPs completed and returned questionnaires; therefore, the response rate was 32.6%.
Approximately 57.8% of participants were male, and 63.4% had less than 20 years of working experience. Information about age, working experience, and the professional setting are summarized in Table . The vast majority of respondents (90.1%, n = 64) were initially trained at the local university in Strasbourg, France. 14.3% of respondents (n = 10) reported to offer orthodontic services in their practices, ranging from 10 to 50 new cases per year. There was no association between the dentist’s age and the provision of orthodontic services ( P = 0.92).
| Variable | n | % |
|---|---|---|
| Age (y) | ||
| 20-29 | 14 | 19.7 |
| 30-39 | 24 | 33.8 |
| 40-49 | 14 | 19.7 |
| 50-59 | 15 | 21.2 |
| 60-69 | 4 | 5.6 |
| Working experience (y) | ||
| 0-9 | 23 | 32.4 |
| 10-19 | 22 | 31.0 |
| 20-29 | 17 | 23.9 |
| 30-39 | 8 | 11.3 |
| ≥40 | 1 | 1.4 |
| Professional setting | ||
| Academic | 3 | 4.2 |
| Solo practice | 22 | 31.0 |
| Group practice | 38 | 53.5 |
| Multidisciplinary practice | 1 | 1.4 |
| Employee | 13 | 18.3 |
| Locum | 0 | 0 |
| Retired | 0 | 0 |
Monitoring and management of bonded retainers
Most of our respondents (83.1%, n = 59) never inserted bonded retainers ( Fig 1 ), but those providing orthodontic services placed fixed retainers significantly more often ( P < 0.001). Approximately 73.2% of GDPs (n = 52) estimated to see between 2 and 10 patients wearing fixed retainers per week, and none saw more than 30 per week. Approximately 78.9% of GDPs reported checking the integrity of bonded retainers during appointments, and no statistical association was found in this matter with working experience nor provision of orthodontic services ( P = 0.12 and P = 0.71). The main reasons mentioned by the GDPs for not checking the fixed retainers’ integrity were “this is part of the orthodontist’s duty” (50.0%) and “lack of knowledge about bonded retainers” (43.7%).
Almost all respondents had already detected a loose retainer (97.2%). This situation seemed to occur once or twice per month, according to 56.7% of GDPs, and 70.0% of respondents thought the mandibular arch to be the most affected. A majority of respondents (77.0%) reported detecting problematic bonding sites either easily or very easily. This was done in different ways ( Fig 2 ). Repairing these bonding failures was a familiar procedure for 47.9% of our respondents, and practitioners offering orthodontic services were more willing to repair them ( P < 0.001). Management of bonding failures differed if the debonded retainer was accompanied or not by tooth movement. If it was not, 45.1% of GDPs rebonded it, and 66.2% referred the patient to an orthodontist ( Fig 3 ). In contrast, if tooth movement was associated with the debonded retainer, the vast majority of respondents referred the patient to an orthodontist (91.6%). In these matters, no statistical difference was found between dentists offering orthodontic services or practioners who did not.
