Bonded versus vacuum-formed retainers: a randomized controlled trial. Part 1: stability, retainer survival, and patient satisfaction outcomes after 12 months.

Background: There is a shortage of evidence on the best type of retainer. Objectives: Evaluate upper and lower bonded retainers (BRs) versus upper and lower vacuum-formed retainers (VFRs) over 12 months, in terms of stability, retainer survival, and patient satisfaction. Trial design: Two-arm parallel group multi-centre randomized controlled clinical trial. Methods: Sixty consecutive patients completing fixed appliance therapy and requiring retainers were recruited from 3 hospital departments. They were randomly allocated to either upper and lower labial segment BRs (n = 30) or upper and lower full-arch VFRs (n = 30). Primary outcome was stability. Secondary outcomes were retainer survival and patient satisfaction. A random sequence of treatment allocation was computer-generated and implemented by sealing in sequentially numbered opaque sealed envelopes independently prepared in advance. Patients, operators and outcome could not be blinded due to the nature of the intervention. Results: Thirty patients received BRs (median [Mdn] age 16 years, inter-quartile range [IQR] = 2) and 30 received VFRs (Mdn age 17 years, IQR = 4). Baseline characteristics were similar between groups. At 12 months, there were no statistically significant inter-group differences in post-treatment change of maxillary labial segment alignment (BR = 1.1 mm, IQR = 1.56, VFR = 0.76 mm, IQR = 1.55, P = 0.61); however, there was greater post-treatment change in the mandibular VFR group (BR = 0.77 mm, IQR = 1.46, VFR = 1.69mm, IQR = 2.00, P = 0.008). The difference in maxillary retainer survival rates were statistically non-significant, P = 0.34 (BR = 63.6%, 239.3 days, 95% confidence interval [CI] = 191.1-287.5, VFR = 73.3%, 311.1 days, 95% CI = 278.3-344.29). The mandibular BR had a lower survival rate (P = 0.01) at 12 months (BR = 50%, 239.3 days 95% CI = 191.1-287.5, VFR = 80%, 324.9 days 95% CI = 295.4-354.4). More subjects with VFRs reported discomfort (P = 0.002) and speech difficulties (P = 0.004) but found them easier to clean than those with BRs (P = 0.001). Limitations: Results are after 1 year and we do not know how much the removable retainers were worn. Conclusions: After 1 year, there is no evidence of a significant difference in stability or retainer survival in the maxilla. In the mandible, BRs are more effective at maintaining mandibular labial segment alignment, but have a higher failure rate. In comparison with patients wearing VFRs, patients wearing BRs reported that they caused less interference with speech, required less compliance to wear them, and were more comfortable to wear than VFRs. Patients found the BRs harder to keep clean. Trial registration: The trail was not registered.

Bonded versus vacuum-formed retainers: a randomized controlled trial. Part 2: periodontal health outcomes after 12 months.

Background: Retainer have the potential to compromise periodontal health. Objectives: Evaluate the periodontal health implications of upper and lower bonded retainers (BRs) versus upper and lower vacuum-formed retainers (VFRs) over 12 months. Trial design: Two-arm parallel group multicentre randomized controlled clinical trial. Methods: Sixty consecutive patients completing upper and lower fixed appliance therapy and requiring retainers were recruited from three hospital orthodontic departments. They were randomly allocated to either upper and lower labial segment BRs (n = 30) or upper and lower full-arch VFRs (n = 30). Periodontal health was assessed using the plaque and gingival indices of Silness and Loe, and the calculus index of Greene and Vermillion. Data were collected at debond and placement of the retainers (T0), 3 months (T1), 6 months (T2), and 12 months (T3). A random sequence of treatment allocation was computer-generated and implemented by sealing in sequentially numbered opaque sealed envelopes independently prepared in advance. Patients, operators, and outcome could not be blinded due to the nature of the intervention. Results: Thirty patients received BRs (median age 16 years, interquartile range [IQR] = 2, 50% female, 50% male) and 30 received VFRs (median age 17 years, IQR = 4, 60% female, 40% male). Gingival inflammation decreased from baseline for both types of retainer. There was significantly less plaque and calculus accumulation and better gingival health with VFRs than BRs over the evaluated 12 months. No serious harm was observed. Limitations: It is not known how much the patients chose to wear their removable retainers. The results reported are after 1 year only. Conclusions: After 1 year, BRs were associated with greater accumulation of plaque and calculus than VFRs and minimally worse gingival inflammation than VFRs, but this did not appear to produce any clinically significant, adverse periodontal health problems. Trial registration: This trial was not registered. Funding: There was no funding.

Do we need primer for orthodontic bonding? A randomized controlled trial.

OBJECTIVE: To evaluate the clinical performance of APC™II Victory Series™ (3M Unitek) brackets in direct orthodontic bonding with and without the use of primer. DESIGN: A single-operator, two-centre prospective, non-inferiority randomized controlled clinical trial. SETTING: The Orthodontic departments at the Leeds Dental Institute and St Luke's Hospital, Bradford, UK. ETHICAL APPROVAL: Ethical approval was granted by Leeds (East) Research Ethics Committee on 18th of December 2009 (Reference 09/H1306/102). PROTOCOL: The protocol was not published prior to trial commencement. SUBJECTS AND METHODS: Ninety-two patients requiring orthodontic treatment with fixed appliances were randomly allocated to the control (bonded with primer) or test groups (bonded without primer). Patients were randomly allocated to either the control or experimental group. This was performed by preparing opaque numbered sealed envelopes in advance using a random numbers table generated by a computer by an independent third party . Once the envelopes were opened, blinding of the operator and the patient was no longer possible due to the nature of the intervention. Patients were approached for inclusion in the trial if they qualified for NHS orthodontic treatment requiring fixed appliances and had no previous orthodontic treatment. MAIN OUTCOME MEASURES: Number of bracket failures, time to bond-up appliances, and the adhesive remnant index (ARI) when bracket failure occurred, over a 12-month period RESULTS: Failure rate with primer was 11.1 per cent and without primer was 15.8 per cent. Bonding without primer was shown statistically to be non-inferior to bonding with primer odds ratio 0.95-2.25 (P = 0.08). Mean difference in bond-up time per bracket was 0.068 minutes (4 seconds), which was not statistically significant (P = 0.402). There was a statistically significant difference in the Adhesive Remnant Index - ARI 0 with primer 49.4 per cent, no primer 76.5 per cent, (P < 0.0001). LIMITATIONS: As the study was only performed by one operator, the results can therefore only be truly be applied to their practice. Also this study was powered to ascertain if there was no difference between the 2 groups up to 5%, however orthodontists may consider a change in the bracket failure rate of 2% to be clinically significant. CONCLUSION: When bonding with APC™II Victory Series™ brackets without primer was shown statistically to be non-inferior to bonding with primer (P =0.08). There was no significant difference in bond-up times. Bond failure was more likely to happen at the composite-enamel interface when bonded without a primer. CONFLICT OF INTEREST: No conflict of interest for all authors. FUNDING: No funding sources were used. REGISTRATION: Study was not registered on external databases.

Orthodontics for treating temporomandibular joint (TMJ) disorders.

BACKGROUND: Temporomandibular disorders (TMD) relate to discomfort of the temporomandibular joint (TMJ). The disorder is multifactorial with a degree of psychogenic influence varying throughout an individual's life with phases of symptoms affecting the quality of life. In an attempt to treat this complex group of disorders many treatment modalities have been identified some of which are also considered in other Cochrane reviews. The disorder also has a normal cycle of events appearing to spontaneously improve without treatment. OBJECTIVES: To establish the effectiveness of orthodontic intervention in reducing symptoms in patients with TMD (compared with any control group receiving no treatment, placebo treatment or reassurance) and to establish if active orthodontic intervention leads to TMD. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. Handsearching of orthodontic journals and other related journals was undertaken in keeping with the Cochrane Collaboration handsearching programme. No language restrictions were applied. Authors of any studies were identified, as were experts offering legal advice, and contacted to identify unpublished trials. Most recent search: 13th April 2010. SELECTION CRITERIA: All randomised controlled trials (RCTs) including quasi-randomised trials assessing orthodontic treatment for TMD were included. Studies with adults aged equal to or above 18 years old with clinically diagnosed TMD were included. There were no age restrictions for prevention trials provided the follow-up period extended into adulthood. The inclusion criteria required reports to state their diagnostic criteria for TMD at the start of treatment and for participants to exhibit two or more of the signs and/or symptoms. The treatment group included treatment with appliances that could induce stable orthodontic tooth movement. Patients receiving splints for 8 to 12 weeks and studies involving surgical intervention (direct exploration/surgery of the joint and/or orthognathic surgery to correct an abnormality of the underlying skeletal pattern) were excluded. The outcomes were: how well were the symptoms reduced, adverse effects on oral health and quality of life. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in triplicate and independently by three review authors. As no two studies compared the same treatment strategies (interventions) it was not possible to combine the results of any studies. MAIN RESULTS: The searches identified 284 records from all databases. Initial screening of the abstracts and titles by all review authors identified 55 articles which related to orthodontic treatment and TMD. The full articles were then retrieved and of these articles only four demonstrated any data that might be of value with respect to TMD and orthodontics. After further analysis of the full texts of the four studies identified, none of the retrieved studies met the inclusion criteria and all were excluded from this review. AUTHORS' CONCLUSIONS: There are insufficient research data on which to base our clinical practice on the relationship of active orthodontic intervention and TMD. There is an urgent need for high quality randomised controlled trials in this area of orthodontic practice.When considering consent for patients it is essential to reflect the seemingly random development/alleviation of TMD signs and symptoms.

Developments in making patients' orthodontic choices better.

CONTEXT: Orthodontics is an unusual speciality as out-patient treatment requires patients to attend services regularly for two to three years. Contact with services is even longer for some patients referred as children, with their parent or carer, and ultimately finishing treatment as autonomous adults. Treatment success is highly dependent on patient co-operation. It is vital for patients to have as good an understanding as possible of what treatment entails, and whether or not it aligns with their expectations, before and during treatment. METHOD: This article reviews evidence of the effectiveness of orthodontic information to enable patient involvement in treatment regimens. It critiques the current provision of information with reference to research from the decision and behaviour sciences about how people make sense of information when making treatment decisions. FINDINGS: Orthodontists provide a lot of verbal and written information about the 'facts' of treatment. This type of information is unlikely to facilitate patients' decisions about, or adherence with, treatments. There is a paucity of evidence describing how: (1) patients make sense of orthodontic problems and treatments, (2) parents manage decision making about their child's treatment, and (3) variation in information needs across the lifespan and treatment experience. PRACTICE IMPLICATIONS: We identified a set of questions to help service providers think critically about the effectiveness of their information provision. Further empirical research is needed to provide evidence to ensure the information included within orthodontic leaflets is relevant to patients and can be assimilated into their existing representations of the problem and treatment.

In search of the sample: recent experiences of a trial team in orthodontics.

Randomised clinical trials are commonly undertaken in medical and dental research. However, few authors discuss the difficulties associated with such studies, including costs, ethical issues and recruitment of an adequate number of patients. There is little information available on the number of studies which are terminated early as a result of these issues, but it seems likely that at least 10% of clinical studies never reach completion. This paper reviews two nationally funded clinical studies which were terminated early. It highlights the problems associated with patient recruitment and also some issues which may benefit researchers undertaking similar studies in the future.