Vacuum-formed Retainers Research Articles

Evaluation of retention protocols among members of the American Association of Orthodontists in the United States

Little research has been conducted to evaluate protocols and trends in orthodontic retention. The purpose of this study was to identify the general retention protocols used by orthodontists in the United States. Additionally, our goal was to identify trends in these orthodontic retention protocols by evaluating how they have changed over the past 5 years and how they might continue to change in the next 5 years. The study was conducted via a 36-question electronic survey (REDCap, Nashville, Tenn) with branching logic on certain questions. The survey was sent to all 9143 practicing members of the American Association of Orthodontists in the United States, and 1632 (18%) responded. Mean retention protocols of the surveyed population showed predominant use of Hawley or vacuum-formed retainers in the maxillary arch and fixed retention in the mandibular arch. For both arches, there is a current shift away from Hawley retainers and toward vacuum-formed retainers and fixed retention. Respondents who extract fewer teeth reported increased use of fixed retention in the maxillary (P = 0.041) and mandibular (P = 0.003) arches. Respondents who extract fewer teeth and use removable retainers were more likely to tell their patients to wear their retainers at night for the rest of their lives (P = 1.63 × 10(-6)).

Patient compliance with orthodontic retainers in the postretention phase

Retention is an important, even critical, component of orthodontic treatment. There is little research on practice protocols and patient compliance with long-term or short-term retention. This lack of information leaves our specialty with many opinions and practice protocols. The purposes of this study were to evaluate and quantify orthodontic retainer wear according to several variables, including patient age, sex, time in retention, and retainer type, and to identify predictors of compliance and reasons for noncompliance with removable orthodontic retainers. Questionnaires were mailed to patients who finished full fixed appliance therapy in either the orthodontic graduate clinic or the orthodontic faculty practice at the University of Kentucky within the past 6 years. Of the 1085 questionnaires mailed, 280 were returned (25.8%). A logistic regression model that described the probabilities of retainer wear was created (P <0.0001). Patient compliance was greater with vacuum-formed retainers (VFRs) for the first 2 years after debonding. However, compliance with VFRs decreased at a much faster rate than with Hawley retainers. Because of this, patient compliance was greater with Hawley retainers at any time longer than 2 years after debonding, and patient compliance overall was greater with Hawley retainers. This evidence disagrees with the current anecdotal trend of orthodontists who favor switching from Hawley retainers to VFRs. An unexpected finding was that patients reported few esthetic concerns about retainers, and the few that were reported were equally distributed between Hawley retainers and VFRs.

Orthodontic treatment for a patient with hypodontia involving the maxillary lateral incisors

Developmental absence of maxillary lateral incisors is not uncommon in orthodontic patients. Treatment depends on a number of factors, including skeletal pattern, type of malocclusion, overjet, and the shape and color of the canines. Management can be broadly divided into space closure, space opening or redistribution, and prosthetic replacement. The purpose of this article was to report the treatment of a girl with an Angle Class I malocclusion with missing maxillary lateral incisors and severe crowding in the mandibular labial segment. Treatment included preadjusted fixed appliances, extraction of the mandibular first premolars, and space closure of the maxillary labial segment space with the canines substituted for the maxillary lateral incisors.

Residents’ journal review

Residents’ journal review

A retrospective randomized double-blind comparison study of the effectiveness of Hawley vs vacuum-formed retainers

To compare Hawley with vacuum-formed retainers. Eighty-two patients who had received treatment with upper and lower fixed appliances were randomly assigned either a Hawley or a vacuum-formed retainer. Study models were fabricated for each patient on day of debond and 2 months, 6 months, and 12 months after debond. Using a specially constructed pantograph, four variables were measured for each set of models at each of these time periods. These were upper and lower intermolar widths, intercanine widths, arch length, and a modified Little's index of irregularity. Method error was determined by repeating the measurements on 10 sets of models. For each of the variables under test and at each of the four time periods, there were no statistically significant differences (α = .05) between each of the two retainers, vacuum-formed and Hawley. The degree of relapse that is likely to occur following a course of fixed appliance therapy is unlikely to be affected by the choice of retainer, vacuum-formed or Hawley. Therefore, when deciding on the type of retainer to be fitted following fixed appliance therapy, other factors such as cost may play a more significant role.

Evaluation of orthodontic treatment after 1 year of retention--a randomized controlled trial

The aim of this study was to use a randomized controlled trial methodology to evaluate and compare three different retention methods. The capacity of the retention methods to retain orthodontic treatment results was in this first phase analysed on a short-term basis, i.e. after 1 year of retention. The subjects were recruited from adolescents undergoing fixed appliance treatment at an orthodontic clinic in the National Health Service (NHS) in Sweden between 2001 and 2007. Seventy-five patients (45 girls and 30 boys with a mean age of 14.4 years at the start of retention) were randomized into three retention systems; a vacuum-formed retainer in the maxilla and bonded canine-to-canine retainer in the mandible (group V-CTC), a vacuum-formed retainer in the maxilla combined with stripping of the 10 proximal surfaces of the lower mandibular anterior teeth (group V-S), and a prefabricated positioner covering the teeth in the maxilla and mandible (group P). The main outcome measures were: Little's irregularity index (LII), intercanine and intermolar width, arch length, overjet, and overbite. Registrations were made before orthodontic treatment, when the fixed orthodontic appliance was removed, and after 12 months in retention. Differences in means between groups were tested by one-way analysis of variance. After 1 year of retention, no clinically significant difference in retention capacity was found between the three retention methods. Small but significant differences (P < 0.05) were observed between the V-CTC and V-S groups regarding mandibular canine width, mandibular arch length, and overbite. In group P, two patients failed to co-operate.

Vacuum-formed retainers more effective than Hawley retainers

A randomised controlled trial (RCT) was performed in a single orthodontic practice. The aim was to compare the clinical effectiveness of Hawley and vacuum-formed retainers (VFR) over a 6-month period of retention. Three hundred and ninety-seven patients were treated by a specialist orthodontist and randomly allocated to wear either Hawley retainers (n=196) or VFR (n=201). A blinded examiner analysed the records of maxillary and mandibular dental casts at debond and at 6 months into retention, assessing tooth rotation mesial to the first permanent molar, intercanine and intermolar widths, and Little's Index of Irregularity. Three hundred and fifty-five individuals participated through to the conclusion of the trial, giving a completion rate of 89%. The results showed significantly greater changes in irregularity of the incisors in the Hawley group than in the VFR group at 6 months. VRF are more effective than Hawley retainers at holding the correction of the maxillary and mandibular labial segments.

Vacuum-formed and Hawley retainers

Vacuum-formed and Hawley retainers

The effectiveness of Hawley and vacuum-formed retainers: A single-center randomized controlled trial

Vacuum-formed retainers (VFRs) are often prescribed by orthodontists in the British National Health Service (NHS). There is no good evidence that VFRs are more effective than Hawley retainers. The aim of this study was to compare the clinical effectiveness of Hawley and VFRs over a 6-month period of retention. The study design was a randomized clinical trial, performed in a single orthodontic practice. Eligible patients treated by a specialist orthodontist were randomly allocated to either Hawley retainers (n = 196) or VFRs (n = 201). Two technicians fabricated the retainers to standardized designs. A blinded, dentally qualified examiner analyzed the records. Maxillary and mandibular dental casts at debond and 6 months into retention were assessed for tooth rotations mesial to the first permanent molars, intercanine and intermolar widths, and Little's index of irregularity. The results showed significantly greater changes in irregularity of the incisors in the Hawley group than in the VFR group at 6 months. There were otherwise no statistically significant differences. VFRs are more effective than Hawley retainers at holding the correction of the maxillary and mandibular labial segments. The median differences were 0.56 mm in the mandibular arch and 0.25 mm in the maxillary arch. Although this difference is unlikely to be clinically significant in the maxillary arch, it could be considered clinically significant in the mandibular arch if located to a single tooth displacement.

Cost-effectiveness and patient satisfaction: Hawley and vacuum-formed retainers

In the United Kingdom (UK) over the last 10 years, there has been a significant increase in the use of vacuum-formed retainers (VFRs) rather than conventional Hawley retainers. There are currently no data to compare the cost-effectiveness of this change in practice. The two aims of this study were to compare (1) the cost-effectiveness of VFRs and Hawley retainers over 6 months, from the perspective of the National Health Service, orthodontic practice, and the patient and (2) patient satisfaction in the two retainer groups. A randomized controlled trial (RCT) was carried out in a specialist orthodontic practice. Three hundred and ninety-seven eligible patients were randomized to one of two retainer groups, and followed up for 6 months. All subjects were invited to complete patient satisfaction questionnaires. Additional data were collected for the cost analysis from the patient records and national databases. Descriptive and bivariate analyses were used to compare patient satisfaction between retainer groups. In all, 196 subjects were randomized to the Hawley group (mean age 14 years 8 months, 63 per cent female, 37 per cent male) and 201 to the VFR group (mean age 15 years, 59 per cent female, 41 per cent male). VFRs were more cost-effective than Hawley retainers from all perspectives. The majority of subjects showed a preference for VFRs compared with Hawley retainers. There were also fewer breakages than in the Hawley group.

Microbial Colonisation On Vacuum-Formed Retainers Constructed On Conventional Models And Three Dimensional (3D) Reconstructed Models

Microbial Colonisation On Vacuum-Formed Retainers Constructed On Conventional Models And Three Dimensional (3D) Reconstructed Models