Orthodontic retention protocols—A survey among Indian practitioners

Introduction

Tendency of teeth to return to their initial positions once active orthodontic treatment has been completed is known as relapse. Patient’s time and money are generally affected by relapse and can also cause esthetic inconvenience because of unfavorable changes that often appears in the front teeth. This kind of situation unsympathetically affects both the patient and the doctor. To restrict or minimize a relapse, some type of retainers should be given to every patient who had undergone orthodontic treatment. This is essential for favorable orthodontic treatment, as the post-treatment stability is unpredictable for any corrected malocclusion. The aim of orthodontic retention is to maximize the stability of the dentition after orthodontic treatment. Relapse is triggered by the recoil of periodontal fibers that clutches the teeth in the jaw bone; pressures from the cheeks, lips and tongue; further growth and the way the teeth meet together.^[1], ^[2]

This logic for retention includes reorganizing the tissue, minimization of changes caused by growth and allowing neuromuscular adaptation to the tooth in corrected position. Retention can be attained by placing appliances on the teeth called retainers, or by performing additional or adjunctive procedures to the teeth or the surrounding structures. Atack mentioned that retainers can either be fixed to the teeth or they can be removable.^[3] in orthodontic treatment various forms of retention are used, the most frequently used retainers are bonded and spring retainers. Many studies, systematic reviews and surveys evaluated orthodontic retention protocols, type of retainers and patient satisfaction.^[4]

The purpose of this study was to identify the different

Materials and Methods

A web-based survey study and was conducted in Department of Orthodontics and Dentofacial Orthopaedics. This survey was conducted for a period of 10 months and included orthodontists practicing in India (all the registered members of Indian Orthodontic Society). This web-based questionnaire was made using Google Forms and questions were modified from Andrikuta et al.^[5], Pasagula et al.^[6] and Valiathan et al.^[7]

Results

Same type of retainer for maxilla and mandible is chosen by maximum. Maximum breakage is seen in fixed retainers and in maxillary arch.

A summary of majority of responses from this study is presented in [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7] in order of the sections the questionnaire was divided.

Discussion

Currently various varieties of removable and fixed retainers are available with varying retention protocols. It is not clear which retainers are the best and for what duration they should be worn.^[5] This study looked into the existing retention protocols used by the Indian orthodontists. A survey which involves all the licensed Indian orthodontists was conducted, and data is obtained to represent the opinions of the specialists on the retention protocols and retention appliance. Majority of Indian orthodontist used same type of retainer for maxilla and mandible with maximum number of them using (combination retainer) fixed lingual retainer with removable retainer which was in agreement with surveys performed in Norway^[8], ^[9] and Lithuania.^[5] Surveys performed in European^{[10] [11]}, ^[12], Saudi Arabia ^[13], Switzerland^[14], ^[7], Australia^[15], Netherland^[16], Iraq^[17], Turkey ^[4][10] revealed, except in Ireland^[17][18] commonly used. There were several maxillary; Switzerland^[14], ^[7] and Netherland ^[16] fixed retainers were most commonly chosen, in USA^[11], ^[12] and in UK^[6], Ireland^[17], and Malaysia^[18] vacuum-formed retainers are chosenfrequently.

Interestingly, this survey showed that orthodontists below 40 years preferred fixed lingual bonded retainer for mandible and thermoplastic vacuum formed retainer for maxilla whereas orthodontists above 40 years preferred fixed lingual bonded retainer for mandible and removable acrylic retainer for maxilla ([Figure 1], [Figure 2]). Even though the stability after orthodontic treatment can be improved by adjuvant applications for retention it was observed that maximum number of orthodontists uses adjunctive procedures which was in favor with the survey done by Turkish^[4] orthodontist.

There was no agreement among Indian orthodontists regarding the duration of retention. Removable retention period of less than 2 years was followed by maximum number of the orthodontics in the present study, which was similar to results with Turkish^[4] orthodontists, whereas United States^[11], ^[12] and Ireland^[17] orthodontist advised lifetime wear. A lifetime period of fixed retainer was advised by maximum number of Indian orthodontists, our results are compatible with Dutch^[19], Swiss^[14], ^[7], America^[11], ^[12], Irish^[15], Iraq^[17], Saudi^[4] and British^[11], ^[12] consultants where maximum orthodontists recommended permanent retention. Lifetime retention is supported by literature indicating that some relapse will occur even after years of orthodontic treatment.^[4] In cases of tongue thrust and diastema lifelong retainer is advised by Indian orthodontist. In this study, maximum number of orthodontists prescribed fulltime removable retainer wear. Similarly, Valiathan and Hughes^[11], Turkish^[4] and Dutch^[19] orthodontists prescribed fulltime wear for 6-9 months. As yet, considering the most recent literature, part-time wear was found to be as effective as full-time wear. Hence in order to increase patient cooperation, a reduction in wear time can be suggested with only the night-time wear regimen.^[4] At the start of treatment almost every respondent informed the patients about the retainers and its need. More than half of the respondents give preference to patient’s choice of retainer. Since extraction is part of treatment in 50% of cases, maximum number of orthodontists feels that extraction influences the types of retainers to be given. Almost 50% of Indian orthodontists get their removable appliance prepared form the commercial lab whereas almost all Indian orthodontist prepare fixed lingual retainer on the patient directly. In cases of fixed lingual bonded retainer, 80% Indian orthodontists preferred 3-3 extent in non-extraction cases and 4-4 extent in extraction cases. Majority of Indian orthodontists uses 0.010” and 0.009” twisted ligature wire as fixed lingual retainer followed by many using multistranded round stainless-steel wire. 42% Indian orthodontists use 1mm thickness of thermoplastic vacuum formed retainer. 70% of Indian orthodontist on an average debond 0-5 cases per month. Following debonding, retainer was delivered on the same day by majority of orthodontists with remaining orthodontists delivering retainer with next 2 days. Most orthodontists scheduled the first retention check-up appointment in first 3 months. This finding was similar to the Arnold et al.^[7] and Pasaoglu et al.^[4] which reported scheduling the first check-up with in the first 3 months after debonding.The months for breakage of retainer, with maximum breakage in fixed retainer, and in maxillary arch. Majority of patients are compliant with thermoplastic vacuum formed retainer.,7) 82% Indian orthodontist includes retention aspect in their consent form and almost every respondent gives instructions to the patient at the time of delivery of retainer with few of them giving written instructions 78% Indian orthodontists recommend personally adapted cleaning instructions; others recommend mouth wash, interdental brush and dental floss. According to this survey, about 25-75% patients follow the instructions given to them and retainer compliance was mainly dependent on the end result, retainer design, comfort and age and doctors explanation.

This study had some limitations: (1) All survey-based studies suffer from a nonresponse error; (2) A few IOS members might not have received this survey if they do not have e-mail or do not use the e-mail address that they gave to the IOS; (3) We did not ask whether previous and future changes in protocols would differ between the mandibular and maxillary arches.

Conclusion

The most commonly used retention protocol among Indian orthodontists is fixed lingual bonded retainer with thermoplastic vacuum formed and extraction largely influences the choice of retainer to be given in a case.

The bonded lingual wire from canine to canine is the most frequent fixed retainer in non-extraction cases and from premolar to premolar is most frequent retainer in extraction cases.

For removable retainer fulltime wear with retention period of less than 2 years is largely followed and 1mm thickness of thermoplastic vacuum formed retainer is used by majority.

lifetime period of fixed retainer is advised by maximum and most commonly used wire for fixed bonded retainer is 0.010” twisted ligature which is directly prepared in patients mouth by majority.

Orthodontists below 40 years preferred fixed lingual bonded retainer for mandible and thermoplastic vacuum formed retainer for maxilla whereas orthodontists above 40 years preferred fixed lingual bonded retainer for mandible and removable acrylic retainer for maxilla.

Factors influencing retainer compliance are comfort, age, explanation by doctor, design of retainer, pre-treatment malocclusion, and post treatment satisfaction.

Source of Funding

None.

Conflict of Interest

None.