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Objective: To analyze factors affecting stability after fixed orthodontic treatment. Methods: Five hundred and forty-four patients who had finished fixed orthodontic treatment more than two years in First Department of Orthodontics, China Medical University from January, 2000 to December, 2017 were investigated and the rate of regular revisit was counted. The data of 288 patients were successfully collected by calling or sending text messages and the rate of standard use of retainers as prescribed (patients wore retainers for 24 months or longer) was counted. According to the variation of peer assessment rating (PAR) index at the start of retention and the time the data collected, the patients were divided into relapse group (variation of PAR index >5) and non-relapse group (variation of PAR index ≤5). Difference significance analysis and multiple-factor logistic regression analysis were used. Sixty patients wearing retainers well were collected and the curative effects of Hawley retainer and vacuum formed retainer (VFR) were compared, which included overbite, overjet, maxillary irregularity index, mandibular irregularity index, width betwenn canine and width between first molar. Results: The rate of regular revisit was 41.0% (223/544). Two hundred and one of 288 patients (69.8%) who were visited successfully had regular revisit, and 60.4%(174/288) of the patients wore retainers well; 30.2% (87/288) of the patients who were visited successfully didn ' t have regular revisit, and 10.4% (30/288) of the patients wore retainers well. Difference significance analysis showed that there was highly significant difference between relapse group and non-relapse group in the type of retainer and duration of retention ( P< 0.01). One hundred and forty of 224 patients (62.5%) in non-relapse group and 37.5% (24/64) of the patients in relapse group used VFR, and the duration of retention in non-relapse group was significantly longer than that in relapse group ( P <0.01). Multiple-factor Logistic regression analysis showed that wearing Hawley retainers ( OR= 3.067, P< 0.05) was the risk factor influencing relapse. The duration of retention ( OR= 0.832, P< 0.01) was the protective factor influencing relapse. Independent-sample t test indicated that the variations of maxillary [(0.82±0.36) mm] and mandibular [(1.05±0.22) mm] irregularity index in Hawley retainer group were larger than maxillary [(0.64±0.29) mm] and mandibular [(0.72±0.35) mm)] irregularity index in VFR group, respectively. The differences between the two groups were significant ( P< 0.05). Conclusions: Duration of retention was implicated in stability after orthodontic treatment. VFR had better effect in the aspects of irregularity index than Hawley retainer. more...

Introduction: The aims of this study were to survey current retention procedures applied by Dutch orthodontists and to examine their acquaintance with "unintentionally active retainers.", Methods: A questionnaire was sent to all 306 Dutch orthodontists involved in patient treatment. Questions were clustered in 4 parts: (1) general information, (2) retention procedures, (3) characteristics of wire materials for bonded retainers, and (4) acquaintance with "unintentionally active retainers.", Results: The response rate was 98%. The most applied retention modality in the maxillary arch was a combination of a removable and a bonded retainer (54%); in the mandibular arch, mainly a bonded retainer without a removable retainer was used (83%). Bonded retention was aimed to be lifelong for the maxillary arch (90%) and the mandibular arch (92%). Mean removable retention duration was 2 years. Vacuum-formed retainers were used more frequently and Hawley-type retainers less frequently. The wire materials used for bonded retainers were diverse. All orthodontists were familiar with unintentionally active retainers; 44% believed this phenomenon is caused by the properties of round multistrand wires. The opinion that unwanted changes in tooth position can arise due to the properties of round multistrand wire material was associated with changing the wire material (P <0.005)., Conclusions: Lifelong retention with bonded retainers continues to increase. All orthodontists were acquainted with unintentionally active retainers and their impact. There is a need to identify all causative factors of inadvertent tooth movement in relation to bonded retainers and to prevent the onset of unintentionally active retainers., (Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.) more...

Objective: The purpose of this retrospective study was to determine the efficacy of Invisalign in a large sample of patients compared to fixed appliances., Method and Materials: The test group consisted of 100 patients treated with Invisalign compared with a control group treated with conventional fixed appliances matched for sex, age, and initial severity of malocclusion based on the amount of anterior dental crowding (Little Index) and the Peer Assessment Rating (PAR Index) scores. The retainer used was a 0.0175-inch multistranded stainless-steel wire bonded from canine-to-canine in the mandibular arch and from lateral inisor-to-lateral incisor in the maxillary arch. A paired t test was used to compare both initial and final PAR scores., Results: There was an overall 80.9% improvement, and 63 subjects did not need any refinement. The mean number of aligners used was 14 (+ 15 for the refinements) in the maxillary arch and 29 (+ 14 for the refinements) in the mandibular arch. The mean duration of treatment was 14 months (+ 7 months for the refinements). Significant statistical differences were found in the posttreatment scores, within both the Invisalign group and the control group. No differences were found in the follow-up scores. Additionally, the duration of treatment was 4 months longer in the control group., Conclusion: More than 90% of the subjects treated with Invisalign achieved a significant improvement, as shown by the PAR scores. A need for additional aligners was reported for 37% of the patients. Fixed bonded retainers seem to be a good option in preventing tooth relapse after Invisalign and fixed conventional treatments. more...

Objectives: To identify the retention protocols practiced by orthodontists in Saudi Arabia, and the factors affecting retainer choice. , Methods: This cross-sectional study took place between February and March of 2015 at the College of Dentistry, University of Dammam, Dammam, Saudi Arabia. A previously tested electronic survey of 34 items was sent to all 1,200 orthodontic members of the Saudi Orthodontic Society. The questionnaire elicited data on the subjects' demographics, orthodontic treatment practices, retention, and post-retention protocols.  , Results: One hundred and sixty-seven (13.9%) responses were received during the study period. The results showed predominant use of Hawley in the maxillary arch (61.3%), and fixed lingual in the mandibular arch (58.5%). Approximately 90.3% recommended full-time maxillary removable retainer wear. Overall, orthodontists who performed fewer extractions tended to use fixed retainers, and those who performed more extractions used removable retainers (p=0.018). Interproximal enamel reduction was used by 28% of the respondents as an adjunct procedure to enhance retention. Approximately 64% practiced a post-retention phase of retainer wear. Participants who used removable retainers most commonly prescribed lifetime retention. , Conclusion: Hawley in the maxilla, and fixed lingual in the mandible were the most common retention protocols prescribed. Lifetime retention was the most common choice for participants who used removable retainers, especially when extractions were carried out. more...

Aim: Several surveys evaluate different retention approaches among orthodontists, but none exist for general dentists. The primary aim of this survey was to record the preferred fixed retainer designs and retention protocols amongst general dentists and orthodontists in Switzerland. A secondary aim was to investigate whether retention patterns were associated with parameters such as gender, university of graduation, time in practice, and specialist status., Methods: An anonymized questionnaire was distributed to general dentists (n = 401) and orthodontists (n = 398) practicing in the German-speaking part of Switzerland. A total of 768 questionnaires could be delivered, 562 (73.2 %) were returned and evaluated. Descriptive statistics were performed and responses to questions of interest were converted to binary outcomes and analyzed using multiple logistic regression. Any associations between the answers and gender, university of graduation (Swiss or foreign), years in practice, and specialist status (orthodontist/general dentist) were assessed., Results: Almost all responding orthodontists (98.0 %) and nearly a third of general dentists (29.6 %) reported bonding fixed retainers regularly. The answers were not associated with the practitioner's gender. The university of graduation and number of years in practice had a moderate impact on the responses. The answers were mostly influenced by specialist status., Conclusion: Graduation school, years in practice, and specialist status influence retention protocol, and evidence-based guidelines for fixed retention should be issued to minimize these effects. Based on the observation that bonding and maintenance of retainers are also performed by general dentists, these guidelines should be taught in dental school and not during post-graduate training. more...

Objectives: Are removable appliances still being routinely used in orthodontic offices? Which methods do clinicians use to assess compliance with wear requirements, and how effective are these methods considered to be?, Subjects and Methods: A questionnaire inquiring about types of treatment, methods of assessing patient compliance with removable appliances, and the perceived effectiveness of these methods was mailed to a sample of 375 members of the German Orthodontic Society ("Deutschen Gesellschaft für Kieferorthopädie", DGKFO)., Results: The rate of returned questionnaires was 29%. Almost all respondents (99%) indicated that they used removable appliances and reported having a "relatively high" proportion of patients currently undergoing such treatment. The most widely used methods of compliance assessment were questioning patients and parents (96%) and examining clinical parameters associated with the dentition and the appliance's fit (95-100%). While these parameters were considered "highly effective", questioning the patients and parents was regarded as "less effective" despite its frequent application., Conclusion: Removable appliances continue to be a standard method of orthodontic treatment. While patient compliance with wear requirements is mainly assessed via indirect clinical methods, the effectiveness of these parameters remains unclear. more...

The purpose of the study was to assess the outcome of orthodontic care in Linköping, Sweden. The dental records of 207 (107 M, 100 F) 19-year-olds registered at one public dental health clinic were studied. A clinical examination was performed where malocclu- sions were registered, where after residual orthodontictreatment need was measured using the Index of Complexity, Outcome and Need (ICON). The 19-year-olds also filled in a questionnaire regarding residual subjective orthodontic treatment demand. Differences between genders were analysed. One hundred and ten (47 M, 63 F) individuals (53.1%) had partaken in orthodontic consultations. Orthodontic appliance treatment had been received by 86 (38 M, 48 F) individuals (41.6%). A residual orthodontic treatment need was registered in 28 (22 M, 6 F) individuals (13.5%). Residual subjective orthodontic treatment demand was expressed by 9 (3 M, 6 F) indi- viduals (4.3%). Eight (2 M, 6 F) of those had no residual treatment need. A higher (p = 0.006) rate of females (63.0%) than males (44.0%) had participated in ort- hodontic consultations. The proportion of males (35.5%) who had experienced orthodontic treatment was not significantly lower (p = 0.069) than among the females (48.0%). However, a lower (p = 0.009) proportion of treated males (55.3%; n = 21 out of 38) than of treated females (81.3%; n = 39 out of 48) had received their treatment by orthodontic specialists. At 19 years of age, the proportion of males with residual treatment need (20.6%) was higher (p = 0.002) than among the females (6.0%). Every patient with orthodontic treatment need and -demand at 19 years of age had previously been offered orthodontic treatment. The conclusion was drawn that the orthodontic care scheme had successfully diagnosed and treated orthodontic problems in the population. However, notable differences between genders regarding treatment modalities and the amount of residual treatment need at age 19 were found. more...

Aim: This survey of Australian orthodontists was conducted to assess treatment preferences., Methods: Email invitations to participate in an online survey were sent to a total of 433 Australian Society of Orthodontists (ASO) members and 158 replies were received (36% response)., Results: For Class II treatment, most practitioners preferred to wait and treat later but when early treatment was performed, the Twin Block was the most popular appliance. For fixed appliance treatment, the 0.022 inch slot was the most commonly used (73%) and the median treatment time was 20 months. The median extraction rate was 23% which was similar to that reported in a 2008 USA survey. Sequential plastic aligners were used by 73% of respondents and Temporary Skeletal Anchorage Devices were used by 77%. The most common research question clinicians would like answered related to retention., Conclusion: The responses were similar Australia-wide but some areas of difference were revealed and discussed. more...

Bonded retainers are considered reliable, independent of patient co-operation, and highly efficient. However, most studies regarding the survival of retainers are retrospective. The aims of this investigation were to prospectively evaluate the failure rate of bonded lingual retainers, the influence of direct or indirect bonding procedures on survival, and to determine the distribution of failures over a 6 month period. Mandibular lingual retainers were bonded in 66 patients. Thirty-two retainers were bonded using a direct method and 34 by an indirect method. There were 23 females and 9 males (mean age 15.96 ± 3.21 years) in the direct group and 29 females and 5 males (mean age 19.44 ± 6.79 years) in the indirect group. A 0.016 × 0.022 inch Bond-a-Braid retainer wire (eight-braided, flattened, stainless steel dead soft wire) was used with Transbond LR. Following bonding, the patients were observed monthly. A chi-square test was used to analyse the influence of the direct and indirect procedures on survival rate.Twenty-five retainers failed. The failure rate was 46.9 per cent with the direct method and 29.4 per cent with the indirect method. The difference between the methods was not statistically significant. The total failure rate was 37.9 per cent. The highest failure rate was seen in the first month. Seven patients had repeated failures. The failure rate was higher in the right quadrant. The total survival rate was 62.1 per cent. more...

The retention after orthodontic intervention is just as important part of the therapy as the activ treatment. It is difficult to find statistical data about the frequency and the average degree of the relapse, but some restitution in lower denture is observable in the 70-90% of the cases, in the postretention period. The upper jaw is also frequently touched, but the prevalence and the rate is milder. The authors of this article tried to collect all the factors which are responsible for the orthodontic relapse and to determine the rules should be kept by the planning and the management of the therapy. The age and the maturity of the patients, the result of the orthodontic intervention, the origin and the character of the anomaly, the type of the retainer, the compliance of the patients; all can influence the chance of the relapse. There are some anomalies which more frequently relapse, contrarily some orthodontic irregularities have quite good long-term prognosis. In the first 6 month after the orthodontic treatment any kind of retainer has to be worn nearly 24 hours/day, later 12-14 hours daily wear seems to be satisfactory. The retention period should be twice longer than the activ orthodontic treatment, posteriorly the appliance can be left gradually. Certainly the length of the retention depends on compliance of the patients. Among the retention appliances the fixed retainers are suggested in the lower front area, because the lower incisors are most frequently relapsed. more...

Introduction: 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., Methods: 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., Results and Conclusions: 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))., Competing Interests: The authors report no commercial, proprietary, or financial interest in the products or companies described in this article., (Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...

Introduction: 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., Methods: 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)., Results: 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., Conclusions: 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., (Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...

Introduction: The purpose of this descriptive study was to estimate retainer wear and compliance among orthodontic patients in the first 2 years after active orthodontic treatment., Methods: A random sample of 1200 orthodontic patients was selected from 4 offices. Data were collected by a self-administered questionnaire that consisted of 6 items: type of retainer prescribed, age, sex, length of time since debond, and hours per day and nights per week that patients wore their retainers. Responses were solicited by mail or the Internet. Data were gathered on a categorical scale and analyzed., Results: The overall response rate was 36% during a 6-week period. In the first 3 months after debond, 60% of patients were wearing their retainers more than 10 hours during a 24-hour cycle, and 69% were wearing the retainers every night. At 19 to 24 months after debond, 19% of the patients were not wearing their retainers, and 81% wore their retainers at least 1 night per week. Compliance rates during the periods of 0 to 3, 4 to 6, 7 to 9, 10 to 12, 13 to 18, and 19 to 24 months were 69%, 76%, 55%, 62%, 45%, and 45%, respectively. Age, sex, and type of retainer did not influence the levels of compliance., Conclusions: Most continued to wear their retainers at least 1 night per week, with compliance rates, as defined, tending to decrease in our sample. It was encouraging that 81% of the patients in this sample largely maintained their orthodontic result., (Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.) more...

Objective: To discern patients' opinions regarding responsibility for orthodontic retention and to determine whether patient attitudes toward retention are related to perceptions of treatment success., Materials and Methods: Questionnaires regarding orthodontic retention were distributed to first-year undergraduate college students (n = 158), first-year dental students (n = 183), and retention patients at orthodontic offices (n = 214). Items included treatment satisfaction, perceived responsibility for retention, type of retainer prescribed, reasons for discontinuing use of retainers, and relapse experienced., Results: Four hundred twenty-eight of 555 participants indicated that they had received orthodontic treatment. Most indicated they were either "satisfied" or "very satisfied" with their teeth, both at the end of treatment (96%) and currently (84%). There was a strong relationship between the perception of stability of tooth position and current satisfaction level (P < .0001). Most individuals (88%) indicated that they themselves were responsible for maintaining the alignment and fit of their teeth. Those who indicated that someone else was responsible were nearly twice as likely to be dissatisfied with their teeth (P = .0496). Patients who had been prescribed clear, invisible retainers were significantly more likely to be "very satisfied" currently (50%) compared to those with Hawley (35%) or permanently bonded (36%) retainers (P = .0002). Patients with Hawley retainers were significantly less likely to be wearing them currently as prescribed (45%) than those with invisible (65%) or bonded (68%) retainers (P < .0001)., Conclusions: Satisfaction with orthodontic results after treatment is related to patient perceptions of responsibility for retention and perceived stability of tooth position. Patients should play a contributory role in formulating orthodontic retention plans. more...

Objective: The aim of this study was to retrospectively assess the frequency and type of lower bonded retainer failures and to analyze the possible influence of operator experience., Patients and Methods: The records of 1062 patients with lower bonded retainers were analyzed with respect to retainer type and failure, timing of failure and differences among operators., Results: 34.9% of all patients experienced retainer failure. Cuspid retainers with two bonding sites failed significantly less often than multiple teeth retainers with six bonding sites. One or more bonding sites became detached in 22.8% of the patients, 17.9% had at least one total retainer loss, while only 0.8% of the patients suffered from retainer fractures. Experienced orthodontists exhibited significantly fewer failures than postgraduate students., Conclusions: The present cohort presented a relatively high failure rate of 34.9%. Lower bonded cuspid retainers failed somewhat less often than 3-3 retainers. In addition less operator experience was likely to correlate with a higher failure rate. more...

The aim of this trial was to compare two different orthodontic retention regimens: is night-only wear of upper and lower Hawley retainers for 1 year as effective as 6 months full-time followed by 6 months night-only wear? Sixty-seven consecutive patients attending for orthodontic debond were randomly allocated to wear upper and lower Hawley retainers either for 1 year night-only (group 1) or for 6 months full-time followed by 6 months night-only (group 2). In group 1, 41.2 per cent were males and 58.8 per cent were females and their mean age was 15.6 years [standard deviation (SD) 1.6 years]. In group 2, 24.2 per cent were males and 75.8 per cent were females and their mean age was 15.8 years (SD 1.2 years). Study models were taken at the start (T0) and end (T1) of treatment and 1 year post-debond (T2). Digital callipers were used to measure upper and lower labial segment irregularity using Little's index and upper and lower labial segment crowding. To evaluate differences between groups 1 and 2 t-tests were used. There were no statistically significant differences between the two retention regimens at T2 for labial segment irregularity or crowding (P > 0.05). Since both retention regimens were equally effective during the 1 year retention period, it would seem clinically acceptable to ask patients to wear their retainers at night only. more...

Introduction: The purpose of this descriptive study was to use a carefully constructed, pilot-tested survey instrument to identify the most common orthodontic retainers and retention protocols prescribed in the United States as reported by active members of the American Association of Orthodontists., Methods: We randomly selected 2000 active members, stratified by region of practice, for the study. Information gathered included, but was not limited to, the types of retainers prescribed in the maxillary and mandibular arches, duration of full-time and part-time wear, use of fixed retainers, appliances fabricated in office vs commercial laboratories, the number of debonds per year, and retention appointment schedules. The survey consisted of 20 questions. Data were gathered on a categorical scale and analyzed., Results: We received 658 responses (32.9%) during a 12-week period. Maxillary Hawley retainers (58.2%) and mandibular fixed lingual retainers (40.2%) were the most commonly used. Most orthodontists prescribed less than 9 months of full-time wear of removable retainers and thereafter advised part-time, but lifetime wear. Most orthodontists (75.9%) did not instruct patients to have the fixed lingual retainers removed at a specific time. More orthodontists who prescribed Hawley retainers recommended longer full-time wear compared with clear thermoplastic retainers. The timing of scheduled retention appointments varied among clinicians and depended on the number of years in practice, the volume of patients debonded, and the type of prescribed retainer. The only regional difference associated with retainer design was the Northeast region, where mandibular fixed lingual retainers were used less frequently. Female orthodontists did not use mandibular fixed lingual retainers as often as their male counterparts., Conclusions: Maxillary Hawley and mandibular fixed lingual retainers are most commonly used. This study is the first to describe retention protocols and the scheduling of retention appointments in the United States. more...

The objective of this study was to survey retention procedures used in orthodontic practices in The Netherlands. A questionnaire was sent to all 279 orthodontists working in The Netherlands. The questionnaire consisted of six parts, mainly containing multiple-choice questions. Information as to background data on the individual orthodontist, retention in general, frequency of different types of removable or bonded retainers that were used, retention protocol, and the type and size of the wire used for bonded retainers was assessed. All statistical analyses were performed using Statistical Package for Social Sciences version 12.0.1. Tests for the relationship between two items were based on the chi-square test. The overall response rate was 91 per cent. Most orthodontists placed a bonded retainer in the upper and lower arch, except when the upper arch was expanded during treatment or when extractions were performed in the upper arch, in which case they placed a removable retainer. Opinions varied with regard to how many hours the removable retainers should be worn and the duration of the retention phase. Contraindications for bonded retainers were given by 96 per cent of the orthodontists, with poor oral hygiene being the most commonly mentioned. As far as bonded retainers were concerned, 84 per cent of the orthodontists preferred permanent retention. Fifty-nine per cent of the orthodontists believed that a practice guideline for retention after orthodontic treatment needs to be developed, which was confirmed by the varied responses in this survey. more...

Objective: To determine whether retention patterns in the UK are influenced by operator gender, age or sphere of practice., Design: Postal self-completed questionnaire., Settings: Private practice, NHS practice, hospital practice and community practice., Subjects: Two hundred and forty orthodontists out of 301 returned their questionnaires (80% response)., Method: Respondents were asked to report on their retention regimes for a hypothetical crowded class II division I case in the one or more practice settings they worked in., Results: Most respondents (61%) worked in more than one practice setting. Vacuum retainers were the most commonly used type in NHS practice and hospital practice while Hawley retainers were frequently used in community practice. Vacuum retainers were also most popular in private practice though often used in conjunction with bonded retainers in both arches, particularly the mandible. Regression analysis revealed that there were no statistically significant associations between retainer preference and gender or age. However, trends were identified that suggested females were less likely to use bonded retainers in the maxilla than males, and older clinicians were more likely to use bonded retainers in the mandible than younger colleagues. Practice setting differences were found to be statistically significant (P< or =0.004) with bonded retainers being more frequently used in private practice., Conclusions: Vacuum retainers are popular in NHS, hospital and private practice. Bonded retainers are more commonly used in private practice than in other settings. more...

Introduction: The V-loop bonded lingual retainer is an innovative design that allows the patient to floss with ease, a significant advantage over the conventional straight wire design for interproximal plaque control. The aim of this retrospective study was to compare the efficacy of straight wire and V-loop fixed retainers with respect to detachment rate when used to stabilize maxillary or mandibular anterior teeth after orthodontic treatment., Methods: Fixed, customized retainers were placed in 300 patients and followed for 6 months. The conventional retainer system was a .0175-in stainless steel multi-stranded wire placed as a straight, bonded lingual retainer. The newer system was a .016-in stainless steel black Australian wire placed in a V-loop design., Results: The detachment rates were 14.3% for the V-loop design and 12.4% for the straight wire retainer. The difference was not statistically significant., Conclusions: The V-loop retainer system addresses cleanability and physiologic adaptability, both critical for the clinical success of bonded lingual retainers used for long-term retention. The interdental wire span of the V-loop design allows easier access for flossing and sufficient flexibility for independent tooth movement in the periodontal space. Patient acceptance of the V-loop bonded lingual retainer was excellent, and most patients in this study found the retainer comfortable and easy to floss. more...

The proposed article is extracted from the author's book entitled "Common Sense Mechanics in Everyday Orthodontics II", published by CSM. In this chapter, the author addresses the biomechanics and treatment of inter-incisal diastemas. The long-term stability of these results is based more on the control of the divergence of the incisal axis and vertical effects of occlusal forces than on the efficiency of the retainer., (Copyright 2009 Collège Européen d'Orthodontie. Published by Elsevier Masson SAS.. All rights reserved.) more...

Purpose: The purpose of this study was to report survival times and problems encountered with laboratory made space maintainers placed over 7 years by one pediatric dentist., Methods: Charts were reviewed for 235 patients with fixed space maintainers placed between January 1, 1997, and December 31, 2003, and followed to December 31, 2005. Problems encountered and appliance lifetimes were recorded and assessed. Failures were recorded as: (1) cement loss; (2) solder breakage; (3) split bands; (4) eruption interference; (5) bent wire; (6) complete loss; or (7) not specified. Appliance outcomes, transferred patients, and those lost to follow-up were recorded., Results: A total of 323 appliances were followed, with: (a) 93 (29%) successes; (b) 110 (34%) still in service; and (c) 104 (32%) known failures. Of the latter, most (62%) were from cement loss (60%) and 13 (12%) were totally lost. No statistically significant differences were noted between types of appliances, gender, and types of failure, except for the fact that bands and loops exhibited more cement loss (P=.045). Mean pooled survival times were between 26 and 27 months.. Of the 104 failures: (a) 34 (33%) were no longer needed (being considered clinically successful); (b) 57 (55%) were recemented; and (c) 13 (12%) were remade. Sixteen appliances were lost to follow-up or transferred., Conclusion: A total of 63% of all space maintainers lasted their anticipated lifetimes or were still in use. more...

Objective: To compare the postretention dental changes between patients treated with Invisalign and those treated with conventional fixed appliances., Materials and Methods: This is a comparative cohort study using patient records of one orthodontist in New York City. Two groups of patients were identified that differed only in the method of treatment (Invisalign and Braces group). Dental casts and panoramic radiographs were collected and analyzed using the objective grading system (OGS) of the American Board of Orthodontics (ABO). The cases were evaluated immediately after appliance removal (T1) and at a postretention time (T2), three years after appliance removal. All patients had completed active orthodontic treatment and had undergone at least one year of retention. A Wilcoxon rank sum test was used to evaluate differences in treatment outcomes between the groups for each of the eight categories in the OGS, including four additional subcategories in the alignment category. A Wilcoxon signed rank test was used to determine the significance of changes within each group from T1 to T2., Results: The change in the total alignment score in the Invisalign group was significantly larger than that for the Braces group. There were significant changes in total alignment and mandibular anterior alignment in both groups. There were significant changes in maxillary anterior alignment in the Invisalign group only., Conclusions: In this sample for this period of observation, patients treated with Invisalign relapsed more than those treated with conventional fixed appliances. more...

Objectives: This survey aimed to identify consistencies in retention procedures., Methods: Three hundred Australian orthodontists and 70 New Zealand orthodontists were randomly selected for the study. A questionnaire gathered their views regarding the most commonly used retainers, wire types and sizes of bonded retainers, factors influencing the design of retainers, duration of regular retention, definition of permanent retention, percentage of cases that needed permanent retention, factors influencing the decision to use permanent retention, changes in retention protocols over the last five years, and reasons for such changes., Results: Upper invisible and lower canine-to-canine bonded retainers were the most commonly used retainers. Pretreatment tooth position was the major factor influencing the design of retainers, and most respondents preferred bonded retainers. The majority preferred multistrand stainless steel wire for bonded retainers. The most common wire size was 0.0175 inch. Orthodontists more commonly recommended a regular retention period of more than two years, and defined permanent retention as "lifetime". Orthodontists applied permanent retention to either a very high or very low percentage of their cases. A high percentage of respondents made changes to their retention protocols over the past five years. There was no relationship between factors influencing the design of retainers and the preferred type of retainer. There was no consensus on the major factor influencing the decision to use permanent retention., Conclusions: Retention procedures are variable and dependent largely on personal preferences. There does not seem to be any consistent pattern in the application of retention methodologies. more...

Bonded retainers have become a very important retention appliance in orthodontic treatment. They are popular because they are considered reliable, independent of patient cooperation, highly efficient, easy to fabricate, and almost invisible. Of these traits, reliability is the subject of this clinical study. A total of 549 patients with retainers were analyzed with regard to wearing time, extension of the retainer, mean time between failures, operator, and age of patient. The average frequency of breakage or loss was 0.55 per retainer per year. This frequency was dependent primarily on the operator who bonded the retainer and on the extent of the retainer. If the upper canines were involved, reliability was lower. The majority of failures occurred during the first 3 to 6 months. The study showed that bonded retainers represent a highly efficient and reliable retention appliance suited to long-term use. more...

This study examined the effects of a number of patient and clinical variables on the breakage of bonded retainers, and consisted of a retrospective review of the survival of 200 bonded retainers. Data was collected from two clinical centres between November 1996 and February 1997. The subjects comprised 198 patients of both sexes divided into three age groups. Retainers at both centres were made in 018-inch co-axial wire with Relyabond and Helioprogress adhesives used at each respective centre. The effects on time to first breakage of adhesive, patient sex, and arch (upper/lower) were considered using Kaplan Meier survival graphs and in Log Rank Tests. Finally, a Cox Proportional Hazard Model was used to examine the joint effects of these factors and the patients' ages. Breakage over a 5-year period with Relyabond was 38.8 per cent upper, 22.1 per cent lower, and with Helioprogress 75 per cent upper and 23.2 per cent lower. Breakage appears to be unrelated to the materials used or to the age and sex of the patients. Upper retainers break more often than lowers (P = 0.016) and early breakage is more likely to occur at an adhesive pad than at a wire (9.6 versus 2.5 per cent within 6 months). more...

Unlabelled: Maintaining the treatment result following orthodontic treatment is one of the most difficult aspects of the entire treatment process. Normal maturational changes, together with post-treatment tooth alterations, conspire against long-term stability. This article discusses the need for retention and provides an overview of retainers which enjoy widespread use., Clinical Significance: Permanent retention is increasingly being recommended as the only way to ensure long-term stability of an orthodontic treatment result. Dental practitioners should be familiar with the rationale for retention and the design of the appliances worn by the their patients. more...

In this study, ten patients who were treated with spring-loaded posterior bite blocks (SLPBB), were evaluated over a period of two years in order to test the effects of the appliance and the incidence of relapse. Successful treatment with SLPBB was achieved in skeletal and dental open bite cases. However, the use of acrylic bite blocks for retention during the post-treatment growth period, did not prevent relapse. more...