Patient compliance with Hawley retainers fitted with the SMART(®) sensor: a prospective clinical pilot study

Patient adherence in orthodontics: a scoping review

BACKGROUND

Patient adherence is a key factor in achieving orthodontic treatment success. Despite an evolution in orthodontic healthcare, no recent comprehensive reviews are available on patient adherence in orthodontics. This scoping review provides an evidence-based overview of the literature available on multiple aspects of patient adherence in orthodontics, during both active treatment as well as during the retention phase. Knowledge gaps identified in the literature are listed.

METHODS

The protocol for this scoping review was registered in the Open Science Framework ( https://doi.org/10.17605/OSF.IO/EC6QD ). Electronic databases and reference lists of relevant studies were searched up to 9 February 2023. The inclusion criteria were studies investigating any form of patient adherence in orthodontics published in English from 2006 onwards. The exclusion criteria were studies investigating adherence in the following patients: those with an intellectual or physical disability that could affect their ability to coincide with their therapist's recommendations and advice, those with oral cleft and craniofacial conditions, and those treated solely for obstructive sleep apnoea. Non-peer-reviewed studies and case reports were also excluded.

RESULTS

A total of 3284 articles were identified, 60 of which met the criteria for final inclusion.

CONCLUSIONS

There is no conclusive evidence on which factors have a significant impact on patient adherence and how patient adherence can be promoted. The degree of patient adherence is generally not compared to achieved treatment results or stability of treatment results, making it difficult to provide clear statements about the impact of the degree of adherence on desired treatment results or orthodontic stability.

Comparison of speech changes caused by four different orthodontic retainers: a crossover randomized clinical trial

OBJECTIVE

This study aimed to compare the influence of four different maxillary removable orthodontic retainers on speech.

MATERIAL AND METHODS

Eligibility criteria for sample selection were: 20-40-year subjects with acceptable occlusion, native speakers of Portuguese. The volunteers (n=21) were divided in four groups randomized with a 1:1:1:1 allocation ratio. The four groups used, in random order, the four types of retainers full-time for 21 days each, with a washout period of 7-days. The removable maxillary retainers were: conventional wraparound, wraparound with an anterior hole, U-shaped wraparound, and thermoplastic retainer. Three volunteers were excluded. The final sample comprised 18 subjects (11 male; 7 female) with mean age of 27.08 years (SD=4.65). The speech evaluation was performed in vocal excerpts recordings made before, immediately after, and 21 days after the installation of each retainer, with auditory-perceptual and acoustic analysis of formant frequencies F1 and F2 of the vowels. Repeated measures ANOVA and Friedman with Tukey tests were used for statistical comparison.

RESULTS

Speech changes increased immediately after conventional wraparound and thermoplastic retainer installation, and reduced after 21 days, but not to normal levels. However, this increase was statistically significant only for the wraparound with anterior hole and the thermoplastic retainer. Formant frequencies of vowels were altered at initial time, and the changes remained in conventional, U-shaped and thermoplastic appliances after three weeks.

CONCLUSIONS

The thermoplastic retainer was more harmful to the speech than wraparound appliances. The conventional and U-shaped retainers interfered less in speech. The three-week period was not sufficient for speech adaptation.

Wearable Orofacial Technology and Orthodontics

Wearable technology to augment traditional approaches are increasingly being added to the arsenals of treatment providers. Wearable technology generally refers to electronic systems, devices, or sensors that are usually worn on or are in close proximity to the human body. Wearables may be stand-alone or integrated into materials that are worn on the body. What sets medical wearables apart from other systems is their ability to collect, store, and relay information regarding an individual's current body status to other devices operating on compatible networks in naturalistic settings. The last decade has witnessed a steady increase in the use of wearables specific to the orofacial region. Applications range from supplementing diagnosis, tracking treatment progress, monitoring patient compliance, and better understanding the jaw's functional and parafunctional activities. Orofacial wearable devices may be unimodal or incorporate multiple sensing modalities. The objective data collected continuously, in real time, in naturalistic settings using these orofacial wearables provide opportunities to formulate accurate and personalized treatment strategies. In the not-too-distant future, it is anticipated that information about an individual's current oral health status may provide patient-centric personalized care to prevent, diagnose, and treat oral diseases, with wearables playing a key role. In this review, we examine the progress achieved, summarize applications of orthodontic relevance and examine the future potential of orofacial wearables.

Orthodontic retention experience of university students: A qualitative study

Objective:

To explore university students’ experience of retention and identify potential barriers and facilitators to long-term adherence.

Design:

Cross-sectional qualitative study using virtual focus groups.

Setting:

University of Leeds.

Participants:

Dental and non-dental students from the University of Leeds, who had previously undergone orthodontic treatment and had received removable retainers.

Methods:

Students were invited to participate via email. Virtual focus groups were undertaken using Microsoft Teams. A topic guide was used to explore the experience of orthodontic retention including factors that influence long-term retainer wear. Focus groups were recorded and analysed using an inductive thematic approach.

Results:

In total, 23 students participated in four focus groups, including 13 dental students. The period since the end of orthodontic treatment varied from 9 months to 10 years. Of the 23 participants, 8 (35%) were no longer wearing their retainers. Four themes were identified: (1) experience of orthodontic treatment including knowledge of relapse; (2) experience of retainer wear, including motivators and barriers; (3) role of others; and (4) increasing adherence. Key factors influencing use of retainers were the importance placed on maintaining treatment outcomes, awareness of unwanted tooth movement and understanding of the role of the retainer, access to replacement retainers, and ongoing support to encourage retainer wear. Greater knowledge and dental awareness reported by dental students did not necessarily increase adherence.

Conclusion:

Adherence to removable retainer wear is an important aspect of orthodontic treatment but it is recognised that long-term retainer wear is highly variable. The understanding of relapse and retention is variable. Challenges in gaining access to replacement retainers are a common cause of cessation of retainer wear. Dental professionals are perceived to be important in encouraging and supporting retainer wear and individuals reported they would like more follow-up.

Orthodontic Compliance Assessment: A Systematic Review

OBJECTIVES

The aim of this review was to determine whether the type of removable appliance, as well as the age and sex of the patient, may affect the extension or reduction of wear time by assessing the correlation between the mean actual and orthodontist-recommended wear times.

METHODS

Randomised case control trials, cohort studies, case series, observational studies, reviews, and retrospective analyses were identified. The quality of the studies was assessed using the Cochrane Collaboration Tool and modified Newcastle-Ottawa Scale. The electronic databases Embase, PubMed, Scopus, and Web of Science were reviewed, and 542 articles were obtained, of which 31 were qualified for qualitative synthesis. The data from 1674 participants were collected and a weighted average was determined for the mean wear time of each appliance.

RESULTS

Regardless of the type of extra- or intraoral appliances, mean wear time was shorter than recommended, although patients using intraoral appliances cooperated more. The best compliance was noted for Schwarz appliances (73.70%) and plate retainers (85%). There was no evidence of an influence of patients' age and sex on compliance during treatment.

CONCLUSIONS

The considerable inconsistency and imprecision of articles could affect the reliability of the results. Previous studies analysing the effectiveness of treatment with removable appliances based on an arbitrarily assumed average wear time need to be revised in order to verify the actual wear time with the use of microsensors.

A two-year comparative assessment of retention of arch width increases between modified vacuum-formed and Hawley retainers: a multi-center randomized clinical trial

Objectives

To compare the clinical effectiveness of Hawley retainers (HRs) and modified vacuum-formed retainers (mVFRs) with palatal coverage in maintaining transverse expansion throughout a 24-month retention period and to assess the subjects’ perception toward the retainers.

Materials and methods

The trial accomplished blinding only by the outcome assessor and data analyst. Data were collected from post-orthodontic treatment patients who met the inclusion criteria. Thirty-five subjects were randomly allocated using a centralized randomization technique into either mVFR (n = 18) or HR group (n = 17). Dental casts of subjects were evaluated at debond (T0), 3-month (T1), 6-month (T2), 12-month (T3), and 24-month retention (T4). The intercanine width (ICW), interpremolar width (IPMW), interfirst molar mesiobuccal cusp width (IFMW1), and interfirst molar distobuccal cusp width (IFMW2) were compared between groups over time using Mixed ANOVA. A pilot-tested and validated questionnaire consisting of six items were given at T4. Subjects were instructed to rate their retainer in terms of fitting, speech, appearance, oral hygiene, durability, and comfort on a 100-mm Visual Analogue Scale (VAS).

Results

No statistically significant differences in arch width were found between the two groups at ICW (P = .83), IPMW (P = 0.63), IFMW1 (P = .22), and IFMW2 (P = .46) during the 24-month retention period. Also, no statistically significant differences were found between perception of both retainers in terms of fitting, speech, oral hygiene, durability, and comfort (P > .05) after 24-month wear. The appearance of mVFRs was rated significantly higher compared to HRs (P < .05).

Conclusions

HR and mVFR have similar clinical effectiveness for retention of transverse expansion cases in a 24-month retention period. Both retainers were perceived to be equal in terms of fitting, speech, oral hygiene, durability, and comfort. Subjects in the mVFRs group found their retainers to be significantly more esthetic than those in HRs group.

Factors Influencing Appliance Wearing Time during Orthodontic Treatments: A Literature Review

This review aims to analyze the multiple factors affecting patients’ level of compliance (how much they wear removable devices/clear aligners) during orthodontic treatments and to investigate the available methods and devices to monitor the appliance wearing time and to improve it. A literature search was conducted on electronic databases (Pubmed, Scopus, and Google Scholar). The results of the present study suggest that compliance indicators may misestimate the intraoral wearing time. Compliance is affected by patient-related factors (age, personality traits, the importance of personal appearance, self-perception of malocclusion), appliance-related factors (visibility, pain/discomfort), and clinician-related factors (trust, clear and complete communication, motivation). The motivation of pre-pubertal patients is mostly external, while adolescents/young adults have intrinsic motivation for orthodontic treatment. Patients’ self-reports tend to overestimate the appliance wearing time. Even if there is a lack of evidence, teledentistry might improve patients’ awareness of being monitored, thus increasing the time for which orthodontic devices are worn. Compliance is a key factor for clear aligner treatments, but high-quality studies focusing on this aspect are missing. Further studies should focus on how to handle the lack of cooperation and how to increase compliance in order to maximize the treatment’s results.

The Use of Microsensors to Assess the Daily Wear Time of Removable Orthodontic Appliances: A Prospective Cohort Study

Orthodontic treatment with removable appliances is still common in children and adolescents. However, their effectiveness depends primarily on the patients’ compliance. Currently, it is possible to check the daily wear time (DWT) of the removable appliances using special microsensors. The aim of this prospective cohort study was to assess the degree of patients’ compliance depending on the type of removable appliance used. In total, 167 patients (87 F, 80 M) were enrolled in the study and were treated with block appliances (Klammt, Twin-Block), Schwarz plates, and block appliances in combination with headgear. All patients were followed up for 6 months with the mean daily wear time checked at followup visits using TheraMon^® microsensors fitted in the appliances. It has been shown that the type of appliance influences the patients’ compliance. The DWT for the Twin Block was significantly longer compared to the DWT for the other appliances. Girls have been shown to wear removable appliances better than boys. It has been proven that the majority of patients do not follow the orthodontist’s recommendations, wearing removable appliances for just over half of the recommended time. Microsensors can be used for objective verification of patients’ compliance, which allows for a reliable assessment of the effectiveness of treatment with removable appliances.

Evaluation of relapse with thermoplastic retainers equipped with microsensors

OBJECTIVES

To examine relapse with thermoplastic retainers equipped with microsensors 1 year after treatment.

MATERIALS AND METHODS

A total of 42 patients (29 females, 13 males) treated with four premolar extractions were included in this study. Thermoplastic appliances equipped with TheraMon microsensors (Handelsagentur Gschladt, Hargelsberg, Austria) were used to assess daily wear time (DWT), and the patients were monitored at 2-month intervals for a period of 12 months. At the end of the follow-up, the following two groups were formed based on the mean DWT: short wear time (SWT; <9 h/d) and long wear time (LWT; ≥9 h/d). Digital models were constructed before treatment (T0), at debonding (T1), and 6 months (T2) and 12 months (T3) after debonding. Little's Irregularity Index (LII) and the intercanine and intermolar widths, arch lengths, overjet, and overbite were calculated based on the digital models. Data were analyzed statistically.

RESULTS

Irregularity and overjet increased, whereas transverse measurements and arch lengths decreased with time in both groups. During the retention period, overbite decreased in the SWT group but increased in the LWT group. There were significant differences between groups only in mandibular irregularity. The LII values of the SWT group were significantly higher than those of the LWT group for the T1-T2 and T1-T3 time intervals (P < .05).

CONCLUSIONS

A mean DWT less than 9 hours/day was inadequate for controlling irregularity within clinically acceptable limits. A wear time of at least 9 h/d is recommended for the maintenance of mandibular anterior alignment.

The effectiveness of a bespoke mobile application in improving adherence with removable orthodontic retention over 12 months: A randomized controlled trial

INTRODUCTION

The primary aim was to analyze the effect of providing a mobile application (My Retainers) on adherence with removable retention.

METHODS

Eighty-four participants planned for thermoplastic retainers were randomly allocated to 2 groups. The intervention group was given access to a bespoke mobile application, while the control group was not given access. Baseline data were obtained at the removal of orthodontic appliances with follow-up at 3 months, 6 months, 9 months, and 12 months. The primary outcome was objectively assessed retainer wear recorded using a TheraMon microelectronic sensor (MC Technology GmbH, Hargelsberg, Austria). Secondary outcomes were stability and periodontal implications.

RESULTS

The objectively assessed wear time at 12 months was low in both groups, being marginally higher in the intervention (median, 3.09 h/d; interquartile range, 8.1) than the control group (median, 1.44 h/d; interquartile range, 9.22) with no between-group statistical difference (P = 0.30, 95% confidence interval [CI], -3.91 to 1.19). No statistically significant difference was identified between the groups in terms of stability and periodontal outcomes. Improvement in plaque scores (P <0.0001; 95% CI, -0.20 to 0.15) and bleeding on probing (P <0.0001, 95% CI, -0.23 to -0.12) was noted over time with no periodontal attachment loss detected over the study period.

CONCLUSIONS

Provision of the mobile application did not lead to improved adherence with thermoplastic retainer wear. Similarly, no benefit in respect of either occlusal stability or periodontal health was observed over the 12-month study period. Further novel approaches to improve adherence with retainer wear and oral hygiene measures are required.

REGISTRATION

NCT03224481.

PROTOCOL

Not published.

FUNDING

This work was supported by funding from the European Orthodontic Society.

Robotic Applications in Orthodontics: Changing the Face of Contemporary Clinical Care

The last decade (2010-2021) has witnessed the evolution of robotic applications in orthodontics. This review scopes and analyzes published orthodontic literature in eight different domains: (1) robotic dental assistants; (2) robotics in diagnosis and simulation of orthodontic problems; (3) robotics in orthodontic patient education, teaching, and training; (4) wire bending and customized appliance robotics; (5) nanorobots/microrobots for acceleration of tooth movement and for remote monitoring; (6) robotics in maxillofacial surgeries and implant placement; (7) automated aligner production robotics; and (8) TMD rehabilitative robotics. A total of 1,150 records were searched, of which 124 potentially relevant articles were retrieved in full. 87 studies met the selection criteria following screening and were included in the scoping review. The review found that studies pertaining to arch wire bending and customized appliance robots, simulative robots for diagnosis, and surgical robots have been important areas of research in the last decade (32%, 22%, and 16%). Rehabilitative robots and nanorobots are quite promising and have been considerably reported in the orthodontic literature (13%, 9%). On the other hand, assistive robots, automated aligner production robots, and patient robots need more scientific data to be gathered in the future (1%, 1%, and 6%). Technological readiness of different robotic applications in orthodontics was further assessed. The presented eight domains of robotic technologies were assigned to an estimated technological readiness level according to the information given in the publications. Wire bending robots, TMD robots, nanorobots, and aligner production robots have reached the highest levels of technological readiness: 9; diagnostic robots and patient robots reached level 7, whereas surgical robots and assistive robots reached lower levels of readiness: 4 and 3, respectively.

Removable retention: enhancing adherence and the remit of shared decision-making

Patient adherence to removable retainer wear is integral to the long-term success of retention regimes. We discuss the factors influencing removable retainer wear, the methods of gauging wear levels, approaches to enhance adherence and the quality of online available information concerning retention. The potential value of patient involvement in approaches to retention within a shared decision-making framework and motivational interviewing are also highlighted.

Effectiveness of removable appliances with temperature sensors in orthodontic patients: a systematic review and meta-analysis

BACKGROUND/OBJECTIVE

Patient compliance during orthodontic treatment is one of the factors that most affects success in the final result. The use of removable appliances is frequent at an early age and the monitoring of its use is essential to assess the collaboration of the patient. The aim of this study was to establish the effectiveness of microsensors included in removable appliances during orthodontic treatment or in the retention phase to enable a reliable and individualized follow-up of the patient.

SEARCH METHODS

The article search was carried out in various electronic databases and journals without any language restrictions.

SELECTION CRITERIA

Studies using microsensors into removable appliances were selected with the key selection criterion of a minimum follow-up of 4 weeks.

DATA COLLECTION AND ANALYSIS

The quality of the studies included was evaluated using the Cochrane scale for the randomized controlled trials and the Newcastle Ottawa Scale for control-case, cohort, and transversal studies. The mean of the differences with a 95% confidence interval was expressed for the continuous data.

RESULTS

Twenty-nine full-text articles were analysed and included in the qualitative synthesis. In general, the mean daily wear time of removable appliances measured objectively was less than the time that the professional had predetermined.

CONCLUSIONS

The use of microsensors as an objective measurement method enhances communication and boosts confidence in the orthodontist-patient relationship. More random clinical studies with temperature sensors are needed to establish to what extent they influence the orthodontic outcome.

REGISTRATION

PROSPERO (CRD42019120525).

Treatment compliance of adolescent orthodontic patients with headgear activator and twin-block appliance assessed prospectively using microelectronic wear-time documentation

Background

Success of orthodontic removable appliance treatment relies on patient compliance. The aim of this quantitative and qualitative study was to explore the compliance and self-reported experience of adolescents in orthodontic treatment with headgear activator (HGA) or twin-block (TB) appliance.

Materials/methods

The study group comprised 52 adolescents with a mean age of 12.6 (±1.3) years at the start of the treatment. The patients were treated at a free-of-charge public dental clinic. Participants were randomly allocated to two equal groups to be treated with either HGA or TB. Patient compliance was evaluated as appliance wear time and subjective experience. Appliance wear time was recorded with Theramon® microchip, and the self-reported subjective experience using a questionnaire.

Results

In total, 30 patients completed the treatment during the follow-up period. HGA was worn on average 7 hours per day and TB 9 hours per day by those patients, who successfully completed the treatment. During a mean observation period of 13 months (range 7–23 months), the mean actual wear time was 43 per cent less than the advised 12 or 18 hours per day in the whole patient group, and 55 per cent in those patients, who completed the treatment. Compliance level was unrelated to the appliance type.

Limitations

Study assessed a relatively small number of patients.

Conclusions/implications

Adolescent patients wear HGA and TB less than advised. Individual variation in treatment adherence is considerable. Thereby, microelectronic wear-time documentation can be a cost-effective mean of identifying non-compliance.

Development of 'My Retainers' mobile application: Triangulation of two qualitative methods

OBJECTIVE

Diligent wear of removable orthodontic retainers requires prolonged adherence and is invariably necessary to preserve optimal results. Patient-informed behaviour-change interventions represent a promising and novel means of enhancing adherence to removable retainer wear. The aim of this study was to describe the development of a patient-informed mobile application designed to enhance retainer wear.

METHODS

App development encompassed consideration of participant preferences, social media posts, available interventions and behaviour change theories. Qualitative methods including analysis of publicly-available retainer-related posts on Twitter (n = 827) and one-to-one interviews were undertaken. Audio-recorded one-to-one interviews were undertaken to identify patient preferences in relation to features, content and design of the application. A criterion-based purposive sample of participants wearing vacuum-formed retainers for at least 4 years was used (n = 15). Thematic analysis of transcribed data was undertaken. These data were triangulated to inform design and content of the application.

RESULTS

The need to facilitate communication with the treating clinician, responsive reminder and tracking systems, and access to useful and engaging written and visual information, in addition to other personalised and interactive features were considered important. Concerns related to retainer wear shared on Twitter informed an exhaustive list of frequently-asked questions. Application features were mapped to relevant theoretical constructs. Determinants of existing behavioural change theories were also used to link application features to retainer wear and maintenance.

CONCLUSIONS

A holistic process involving both patient and professional input can be useful in informing the development of mobile applications. The orthodontic application ("My Retainers") will undergo further scrutiny in relation to its effectiveness in inducing behavioural change and concerning patient experiences prior to finalisation.

Users' perceptions and preferences towards maxillary removable orthodontic retainers: a crossover randomized clinical trial

The aim of this study was to assess, correlate, and compare users' perceptions and preference related to maxillary removable retainers. Volunteers were recruited to use four retainer types: conventional wrap-around (CWA), wrap-around with an anterior opening (OWA), "U" wrap-around (UWA), and clear thermoplastic retainer (CT). The main outcomes were the volunteers' perceptions, evaluated with a 100-mm visual analogue scale, and their preferred retainer. The retainers were used for 21 days each (washout intervals of 7 days). Nineteen volunteers (27 ± 4.53 years) were randomly divided into four groups that used the four retainers, but with a different sequence. Perceptions were evaluated immediately after the use of each retainer and the preference at the end of the research. Repeated measures ANOVA and Friedman tests with post-hoc Tukey's test (intergroup comparisons), and Pearson and Spearman analyses (correlations between perceptions) were applied. The WA retainers did not significantly differ among themselves. The CT was rated significantly worse in speech (p ≤ 0.001), discomfort (p < 0.001), and occlusal interference (p < 0.001), and did not significantly differ from the others in esthetics. Users preferred significant more the WA retainers in comparison with the CT retainers. The occlusal interference caused by the CT was positively correlated to other perceptions, such as changes in speech and discomfort. WA retainers presented similar preference and perceptions, but were significantly better than the CT. The CT occlusal coverage appeared to be the primary cause of its rejection.

Headgear compliance as assessed by a temperature-sensitive recording device: a prospective clinical study

Objective

To accurately describe compliance in headgear wearing time by using a temperature- and force-sensitive device over an 8 month period of use in a prospective clinical manner.

Materials and methods

Twenty children with Class II malocclusion aged 8–12 years were randomly selected for treatment with cervical headgear. The headgears were equipped with an electronic module, which measured temperature and force, and patients were instructed to wear the headgear 12 hours daily. The recorded values were analysed to determine the number of days the headgear was used, the number of hours per day it was worn, and the percentage of compliance (100 per cent corresponding to 12 hours daily).

Results

The average treatment period was 8.4 months with 5.8 months of effective use. When effectively used, headgear was worn 8.7 hours a day (compliance of 73 per cent). Including days where it was not worn, compliance was 6.4 hours (54 per cent). The appliance was used on average 0.5 hours during the day (8 am–8 pm) and 5.9 hours during the night (8 pm–8 am). Very low compliance was recorded during July and August.

Conclusion

The average compliance with cervical headgear use was 54 per cent of the 12 hour prescription. The headgear was effectively used only 5.8 months over the study period, with roughly 30 per cent of no use. Headgear was used almost exclusively during evening and night-time. During the summer period, compliance was particularly poor.

Performance of Hawley-type retainers: a systematic review of randomized clinical trials

Background

Although post-treatment changes are almost inevitable, and retention has long been recognized as one of the most critical and routine problems faced by orthodontists, there remains a lack of certainty regarding the parameters of any definitive retention protocol following orthodontic treatment.

Objective

To investigate the performance of the Hawley-type retainers.

Search methods

Search without restrictions in 15 databases and hand searching until December 2016.

Selection criteria

Randomized clinical trials comparing the performance of Hawley-type retainers to other removable appliances or comparing different Hawley-type retainers' wearing schedules.

Data collection and analysis

Following study retrieval and selection, data extraction and individual study risk of bias assessment using the Cochrane Risk of Bias Tool took place. The overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation approach.

Results

Finally, 10 studies were identified involving 854 individuals, followed for up to 1 year after debonding. Eight studies compared subjects using Hawley and clear thermoplastic retainers; another compared Hawley to positioner and, finally, one trial involved individuals allocated to different Hawley appliance wearing schedules. Three studies were considered as being of low, four of unclear, and three of high risk of bias. In general, few differences were observed between the Hawley and other removable retainers regarding outcomes relevant to maxillary and mandibular dental arch measurements, dental arch relationships and occlusal contacts, speech evaluation, patient reported outcomes, adverse effects, and problems related to the appliances, as well as economic evaluation related outcomes. Moreover, no differences were observed between the compared Hawley wearing schedules. Overall, the quality of the available evidence was considered low.

Conclusions

Given the overall quality of the available evidence and the multitude of parameters, which may have affected the results of the included trials, good practice would suggest further research in the respective field in order to increase both the quantity and quality of information available.

Registration

PROSPERO (CRD42015029279).

Funding

No funding was received for the present systematic review.

Stability of orthodontic treatment outcomes after 1-year treatment with the eruption guidance appliance in the early mixed dentition: A follow-up study

OBJECTIVES

To investigate occlusal stability from the early mixed to the permanent dentition in children after early treatment with the eruption guidance appliance (EGA).

MATERIALS AND METHODS

Of 46 participants who received 1-year early EGA treatment, 35 attended a follow-up examination at age 12. Group 1 (n = 21) started their EGA treatment at mean age 7.7 years, and group 2 at 9.1 years. Following 1-year treatment, the EGA was used as a retainer. Changes in overjet, overbite, sagittal molar relationship, and anterior crowding were measured on casts obtained before EGA treatment, after EGA treatment, and at follow-up to evaluate occlusal stability.

RESULTS

Mean overjet, overbite, sagittal molar relation, and mandibular crowding improved significantly during the study period. Participants with good compliance during the retention period had significantly smaller overjet and overbite values than those with poor compliance.

CONCLUSIONS

Early correction of increased overjet, overbite, and class II molar relation with the EGA is maintainable and can also be effective in the permanent dentition, provided the EGA is worn regularly as a retainer.

Periodontal health and compliance: A comparison between Essix and Hawley retainers

INTRODUCTION

Many studies on removable retainers have focused on retention efficacy and characteristics. However, studies on plaque accumulation, periodontal health, breakages, and patient compliance are still lacking. Thus, in this study, we aimed at evaluating these parameters in 2 groups of young patients wearing Essix or Hawley retainers for a 6-month period.

METHODS

Seventy subjects were included. Periodontal health was investigated by measuring the plaque, gingival, calculus, and bleeding on probing indexes. Evaluations were performed at 1, 3, and 6 months of wearing. Accumulation of plaque on the retainers was also evaluated. Furthermore, compliance on wearing retainers and breakage data were collected by specific questionnaires.

RESULTS

Subjects wearing Essix retainers had significantly higher levels of plaque, gingival, and calculus indexes and increased percentages of bleeding sites, compared with subjects wearing Hawley retainers. The Essix group also had increased accumulations of plaque and calculus on the retainers. Nonetheless, subjects of the Essix group had better overall experiences, self-perceptions, and comfort compared with those of the Hawley group. Essix retainers had higher incidences of little and serious breakages compared with Hawley retainers.

CONCLUSIONS

Our results suggest that Essix retainers are well accepted by patients for their esthetic and oral comfort characteristics. However, Essix retainers may cause greater accumulations of plaque on both teeth and retainers, presumably because of inhibition of the cleaning effect of saliva caused by the thermoplastic material or the reduced opportunity for good hygiene on the retainer.

Compliance with removable orthodontic appliances

Data sourcesMedline via OVID, PubMed, Cochrane Central Register of Controlled Trials, Web of Science Core Collection, LILACS and BBO databases. Unpublished clinical trials accessed using ClinicalTrials.gov, National Research Register, ProQuest Dissertation and Thesis database.Study selectionTwo authors searched studies from inception until May 2016 without language restrictions. Quantitative and qualitative studies incorporating objective data on compliance with removable appliances, barriers to appliance wear compliance, and interventions to improve compliance were included.Data extraction and synthesisQuality of research was assessed using the Cochrane Collaboration's risk of bias tool, the risk of bias in non-randomised studies of interventions (ROBINS-I), and the mixed methods appraisal tool. Statistical heterogeneity was investigated by examining a graphic display of the estimated compliance levels in conjunction with 95% confidence intervals and quantified using the I-squared statistic. A weighted estimate of objective compliance levels for different appliances in relation to stipulated wear and self-reported levels was also calculated. Risk of publication bias was assessed using funnel plots. Meta-regression was undertaken to assess the relative effects of appliance type on compliance levels.ResultsTwenty-four studies met the inclusion criteria. Of these, 11 were included in the quantitative synthesis. The mean duration of objectively measured wear was considerably lower than stipulated wear time amongst all appliances. Headgear had the greatest discrepancy (5.81 hours, 95% confidence interval, 4.98, 6.64). Self-reported wear time was consistently higher than objectively measured wear time amongst all appliances. Headgear had the greatest discrepancy (5.02 hours, 95% confidence interval, 3.64, 6.40). Two studies found an increase in compliance with headgear and Hawley retainers when patients were aware of monitoring. Five studies found younger age groups to be more compliant than older groups. Three studies also found compliance to be better in the early stages of treatment. Integration between quantitative and qualitative studies was not possible.ConclusionsCompliance with removable orthodontic appliances is suboptimal. Patients wear appliances for considerably less time than stipulated and self-reported. Compliance may be increased when patients are aware of monitoring; however, further research is required to identify effective interventions and possible barriers in order to improve removable orthodontic appliance compliance.

The effects of fixed and removable orthodontic retainers: a systematic review

OBJECTIVE

In the view of the widespread acceptance of indefinite retention, it is important to determine the effects of fixed and removable orthodontic retainers on periodontal health, survival and failure rates of retainers, cost-effectiveness, and impact of orthodontic retainers on patient-reported outcomes.

METHODS

A comprehensive literature search was undertaken based on a defined electronic and gray literature search strategy (

PROSPERO

CRD42015029169). The following databases were searched (up to October 2015); MEDLINE via OVID, PubMed, the Cochrane Central Register of Controlled Trials, LILACS, BBO, ClinicalTrials.gov, the National Research Register, and ProQuest Dissertation and Thesis database. Randomized and non-randomized controlled clinical trials, prospective cohort studies, and case series (minimum sample size of 20) with minimum follow-up periods of 6 months reporting periodontal health, survival and failure rates of retainers, cost-effectiveness, and impact of orthodontic retainers on patient-reported outcomes were identified. The Cochrane Collaboration's Risk of Bias tool and Newcastle-Ottawa Scale were used to assess the quality of included trials.

RESULTS

Twenty-four studies were identified, 18 randomized controlled trials and 6 prospective cohort studies. Of these, only 16 were deemed to be of high quality. Meta-analysis was unfeasible due to considerable clinical heterogeneity and variations in outcome measures. The mean failure risk for mandibular stainless steel fixed retainers bonded from canine to canine was 0.29 (95 % confidence interval [CI] 0.26, 0.33) and for those bonded to canines only was 0.25 (95 % CI: 0.16, 0.33). A meta-regression suggested that failure of fixed stainless steel mandibular retainers was not directly related to the period elapsed since placement (P = 0.938).

CONCLUSION

Further well-designed prospective studies are needed to elucidate the benefits and potential harms associated with orthodontic retainers.

Assessment of Factors Affecting Adolescent Patients' Compliance with Hawley and Vacuum Formed Retainers

INTRODUCTION

Success of orthodontic retention with removable retainers almost entirely depends on patients' compliance.

AIM

This study was carried out to investigate the relationship between adolescent orthodontic patients' compliance and various clinical and social factors.

MATERIALS AND METHODS

The data were collected from 77 orthodontic patients aged 7-11 years old who had finished the full fixed appliance therapy. Hawley's retainers were used in 34 patients and 43 patients used Vacuum Formed Retainers (VFRs). The subjects completed a questionnaire including several identifiers allowing the respondents to be classified into subgroups. They were also asked to indicate how long they wore their retainers during the day, by writing the number of hours in the report-card for the next three months. Comparison of the results was performed by one-way ANOVA and independent sample-t tests.

RESULTS

No significant differences were found between males and females. Type of the retainer, patients' grade of study, mothers' occupation, clinicians' and parents' attitudes and filling the report cards had significant effect on mean wear hours per day. When compliance of the patients was assessed according to treatment location, Living place, parents' educational degrees and ethnicity, no significant differences could be found.

CONCLUSION

The adolescent patients' compliance was greater with VFRs than with Hawley's retainers. Parental attitude and doctor-patient relationship had a great impact on adolescent patients' compliance.

A feasible method to improve adherence of Hawley retainer in adolescent orthodontic patients: a randomized controlled trial

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%).

CONCLUSION

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.