Article

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

September 2007
The European Journal of Orthodontics 29(4):372-8

Source
PubMed

Authors:

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.

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

Article

Full-text available

Aug 2022

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.

Comparative Assessment of Patient’s Acceptability between Hawley and Vacuum-Formed Retainer in Patients Treated with Fixed Orthodontics Appliance

Article

Jun 2023

Objective: To compare the acceptability of Vacuum-formed Retainers and Hawley Retainers in two groups of fixed orthodontics patients over three months. Study Design: Quasi-experimental study. Place and Duration of Study: Armed Forces Institute of Dentistry, Rawalpindi Pakistan, from Jan 2019 to Mar 2020. Methodology: Eighty-two Patients treated with fixed orthodontics appliances in the department of orthodontics of Armed Forces Institute of Dentistry, who met the inclusion and exclusion criteria were recruited for the study. Patient acceptance was evaluated through a ten-question questionnaire regarding biting, fitting, hygiene, speech, swallowing, appearance, selfconfidence, gingival irritation, durability and comfort. Patients were evaluated on a 10cm long Visual analogue scale over three months in the post-orthodontics retention phase, after one week (T1), one month (T2) and three months (T3) of follow-up. Results: The vacuumed-formed retainer was significantly better in terms of speech (p<0.01), appearance (p<0.001), durability (p<0.001), gingival irritation (p<0.001), swallowing (p<0.001), self-confidence, and comfort (p<0.001). There was no significant difference in terms of fitting, hygiene and biting. Conclusion: The vacuumed-formed retainer was significantly better accepted in terms of speech, swallowing, appearance, self confidence, durability, gingival irritation and comfort.

A survey of patient compliance with removable orthodontic retainer wear in Brunei Darussalam

Article

Full-text available

Mar 2023

Objective To explore compliance with removable orthodontic retainer wear among patients who had completed fixed appliance orthodontic treatments. Materials and methods A cross-sectional online survey was distributed to patients who had completed orthodontic treatment at the government orthodontic clinics. The response rate was 54.9%, 663 questionnaires were distributed and 364 responses were received. Demographic information was collected, and questions regarding types of retainers prescribed, instructed and actual wear times, satisfaction levels, and reasons for wearing and not wearing retainers. Chi Square, Fisher’s Exact tests and Independent T-Test were used to detect significant associations between variables. Results Respondents under 20 years old and employed were the most compliant. The mean satisfaction levels of Hawley Retainer and Vacuum-Formed Retainer were reported to be 3.7 ( P = 0.565). About 28% of those in both groups stated that they wear them to maintain their teeth straight. 32.7% of Hawley retainer wearers reported not wearing their retainers due to speech difficulties. Conclusion Age and employment status were the variables that determined compliance. There was no significant difference in the satisfaction levels between the two retainer types. Most respondents wear their retainers to keep their teeth straight. Discomfort and forgetfulness were the primary reasons for not wearing retainers, besides speech difficulties.

Comparison of the Esthetic Perception and Economic Value of Different Removable Orthodontic Retainers for the Upper Arch

Article

Sep 2024

Objective: This cross-sectional study aimed to compare the esthetic perception and economic value between two maxillary removable retainers, considering gender, age, and socioeconomic status. Material and Methods: Photographs of the smiles of 2 volunteers using Hawley and Vivera® retainers were evaluated by 408 laypeople who answered a web-based survey with questions regarding participants' characteristics, retainers' esthetic perception, and economic value (willingness to pay). Descriptive statistics were performed, and the responses were analyzed using independent t-test, ANOVA, Tukey test, and chi-square. Results: Vivera® was considered the most esthetic retainer for both smiles, without a statistically significant difference between raters’ genders. Raters over 46 years old judged with statistically significant greater values the Hawley and Vivera® of male smiles (p=0.01; p=0.02 respectively) and C2 socioeconomic status to the Hawley for the female smile (p=0.02). Considering the economic value, both genders and the different status demonstrated a similar willingness to pay more money for Vivera® as well as a similar amount of money they would be willing to pay. Statistically significant associations were observed between age ranges and economic values; more respondents aged between 18-30 years old reported being more willing to pay for Vivera® (p=0.03); however, when the value was asked, the participants aged more than 46 years old were more willing to pay greater prices for Vivera® (p=<0.01). Conclusion: The Vivera® was considered more aesthetically pleasing, and most laypeople would pay more for this retainer. However, most were willing to pay an extra value smaller than the laboratory’s cost difference.

CAD-based functional therapy during aligner treatment – the “En-Nova”-protocol (technical report)

Article

Full-text available

Jul 2024
Semin Orthod

Functional orthodontic therapy represents a fundamental element of orthodontic therapy, intending to correct skeletal discrepancies of growing patients by changing their neuromuscular patterns on the long run. To date, consequent functional orthodontic therapy is the first part of a two-phase treatment protocol, which is followed by subsequent dental alignment. For aligners several features are present, which aim to integrate functional therapy into aligner treatment. Examples include inclined planes (“precision wings”) incorporated into the aligners or elastics, both trying to force a mandibular advancement. However, all of them suffer from a rather small skeletal effect, which is why the development of new approaches, which allow for more growth control during aligner therapy, is justified. Against this background, the present article describes a new treatment concept which consists of a CAD-based functional orthodontic appliance overlaying over the aligners during the entire treatment time. By increasing the skeletal control, it is intended to guarantee a consequent functional orthodontic treatment while saving treatment time.

A digital CAD/CAM configurator for the production of orthodontic appliances – Going new ways

Article

Full-text available

Jul 2024
Semin Orthod

An In Vivo Study to Compare the Clinical Effectiveness of Clear Retainer Made on a Conventional and a Digitally Fabricated Model Over a Six-Month Period After Debonding

Article

Full-text available

Feb 2024

Background With the advent of 3D printing, many more possibilities have arisen for treatment planning. 3D rapid prototyping has enabled us to see a whole other dimension that has helped us to give the best possible care for our patients. With more and more advancements being made in this subject, it becomes necessary to check the reliability of the equipment and its effectiveness in the management of the problem at hand. This original study was conducted with the aim of checking the accuracy, dimensional stability, and reliability of orthodontic retainers made on a conventional and digitally fabricated model over a six-month period after debonding. Material and methods The patients were selected from those who have completed fixed orthodontic mechanotherapy from the Department of Orthodontics and Dentofacial Orthopaedics, Sri Guru Ram Das Institute of Dental Sciences and Research, Sri Amritsar. Fifty patients received a clear retainer, which was fabricated for the upper and lower arch after removing the brackets. Patients were included in this study irrespective of their age groups. The manual method used a vacuum-forming machine to fabricate six retainers on stone models. In the digital method, new impressions were taken after three months, and digital models were obtained through 3D scanning and printing, followed by clear retainer fabrication. The data were gathered through a systematic process involving manual and digital methods for clear retainer fabrication and subsequent evaluation. The data obtained was computed for statistical evaluation and comparison. Results Mean and standard deviations of conventional (manual) and digital variables in the two groups were calculated. An ANOVA test was used to evaluate statistically significant differences for mesiodistal width and buccolingual width, and a post hoc Tuckey test was applied for multiple comparisons. The results indicated that most mesiodistal and buccolingual width measurements showed non-significant variations and exhibited a good correlation. Extraction space opening, assessed through an independent t-test for both the maxilla and mandible, also yielded non-significant and comparable results. Additionally, intra-operator and inter-operator measurements using a digital caliper demonstrated high agreement. Intra-class correlation (ICC) values exceeded 0.75, and inter-operator ICC results reflected a high level of agreement ranging from 0.8 to 0.99. Conclusion The primary objective of this study was to establish a correlation between the accuracy, dependability, and clinical efficacy of orthodontic retainers produced using both conventional and digitally created models. This investigation spanned a duration of six months following the removal of orthodontic brackets. The results showed that most of the statistically significant values were due to the inherent potential of the 3D printer for polymerization shrinkage, which, being a stereolithographic 3D printer, had a potential for a slight dimensional shift in the transverse dimension. However, the mean difference between all the models printed was slight and clinically insignificant.

Comparison of light transmittance and color changes between polyurethane and copolyester retainer materials after staining and destaining

Article

Full-text available

Jan 2024
BMC Oral Health

Background Retainers are the only effective approach to prevent orthodontic relapse. The aim of this study was to compare the changes in color and light-transmittance of rough and smooth thermoformed polyurethane and copolymer retainer samples after staining in different solutions and destaining with different approaches. Methods Four hundred copolyester (Essix® ACE) and 400 polyurethane (Zendura®) samples with different surface textures, smooth and rough, were stained in 4 different solutions (n = 100 per solution) over 28 days. Each of the four groups of 100 stained samples of each material was subdivided into 5 groups of 20 samples and subjected to different destaining solutions. Light transmittance and color changes were evaluated using a spectrometer and a spectrophotometer. Mean differences were compared using a two-way analysis of variance (ANOVA) and posthoc multiple comparison tests at P = 0.05. Results No significant differences in light transmittance were found between both untreated materials. Both materials were stained in a similar fashion and showed no significant differences between two materials after staining. Coffee and tea stained both materials more significantly than wine, but there was a significant difference of changes of color and light transmittance between rough and smooth surfaces during the destaining in coffee- and tea-stained samples of copolyester material. All destaining solutions were effective at removing all stains on the samples. The surface roughness of the material plays a significant role in the ability of the materials to be destained, demonstrating a more significant greater effect on cleaning rough samples for improvements in light-transmittance and greater changes in color. Conclusions This study concluded that the surface of materials plays a significant role in the material destaining and staining. In addition, the different polymers used for retainer fabrication exhibited different responses during the destaining process depending on types of stains.

Termoplastik pekiştirme apareylerini temizleme yöntemleri ve etkileri

Article

Full-text available

Jan 2024

Estetik ve şeffaf olması sebebiyle termoplastik pekiştirme apareylerine ilgi giderek artmaktadır. Pekiştirme tedavisi sırasında hastalardan bu apareyleri yemek dışında tam zamanlı kullanmaları, apareyler ağızdayken su dışında bir şey yiyip içmemeleri ve apareylerini iyi temizlemeleri istenmektedir. Ortodontistler bu apareylerin hijyeninin sağlanması için farklı yöntemler önermektedirler. Bilimsel literatür fırçalama ve kimyasal ajanlarla temizliğin en popüler yöntemler olduğunu göstermektedir. Uzun süreli kullanım ve tekrarlayan temizleme siklusları termoplastik pekiştirme apareylerinin mekanik ve fiziksel özelliklerini bozabilmektedir. Apareyler nem, ısı ve tükürük enzimlerine maruz kaldığında değişikliğe yatkındır. Etkili bir temizleme yöntemi kullanım ömrünü uzatır ve hastanın tedaviye uyumunu artırır. Termoplastik pekiştirme apareylerinin hijyeninin sağlanmasında herhangi bir yaklaşımın hastaya tavsiye edilebilmesi için kullanılan yöntemlerin avantaj ve dezavantajlarının iyi bilinmesi önemlidir. Bu nedenle derlemenin amacı; termoplastik pekiştirme apareylerinin temizliğinde kullanılan yöntemler ve etkilerini araştırmış olan çalışmaların sonuçlarını incelemektir. Interest in thermoplastic retention appliances has increased due to their aesthetic and transparent nature. During retention, patients are told to use these appliances full-time except for meals, not to eat or drink anything other than water while the appliances are in place, and to clean their appliances well. Orthodontists suggest different methods to ensure the hygiene of these appliances. The scientific literature shows that brushing and cleaning with chemical agents are the most popular methods. Longterm use and repetitive cleaning cycles can deteriorate the mechanical and physical properties of thermoplastic retention appliances. These appliances are prone to change when exposed to moisture, heat and salivary enzymes. An effective cleaning method prolongs the life of these appliances and could increase compliance with the treatment. In order to be able to recommend a specific method to the patient in ensuring the hygiene of thermoplastic retention appliances, it is important to know the advantages and disadvantages of various cleaning methods. Therefore, our purpose is to review the studies which have investigated the cleaning methods of the thermoplastic retention appliances and their effects.

Termoplastik Pekiştirme Apareylerini Temizleme Yöntemleri ve EtkileriCleaning Methods of Thermoplastic Retention Appliances and Their Effects

Article

Feb 2023

Blanket or tailored prescription of retainers in orthodontics: a questionnaire-based study

Article

Dec 2023

Objective To explore retainer protocols and how they are influenced by orthodontic presentation and the nature of occlusal correction. Materials and Methods A prepiloted 45-item online questionnaire targeting orthodontists was developed. The questionnaire covered clinical preferences in terms of retainer type, fabrication, and follow-up during retention; the clinical indications for adjunctive surgical procedures; and the use of active designs to mitigate relapse in specific malocclusions. Results A total of 206 responses were obtained. The majority of the respondents prescribed maxillary removable and mandibular fixed retainers, with almost half (49.1%) reviewing patients for more than 1 year primarily in person (95.1%). The majority prescribed vacuum-formed (69.6%) 1-mm-thick (44.3%) retainers. Only 37.3% were aware of the type of material used, with polyethylene terephthalate glycol copolymer, followed by polypropylene, being the most common. Hawley retainers were preferred following nonsurgical maxillary expansion and with suboptimal interdigitation. A preference for clear retainers and/or fixed retainers was found in open-bite cases and deep-bite cases. Supracrestal fiberotomy was prescribed commonly (61.1%) for rotations greater than 90°. No retainer was rarely prescribed except after the correction of an anterior crossbite. Conclusions Blanket prescription of orthodontic retention is common, with limited awareness of clear plastic retainer materials. Future trials evaluating the effectiveness of approaches for retainer prescription based on the presenting malocclusion would be timely.

Herausnehmbare kieferorthopädische Apparaturen im CAD/CAM-Verfahren mit Fokus auf CAD-FR3

Article

Sep 2023

Die CAD/CAM- (Computer Aided Design/Manufacturing) Technik, also die digitalisierte Planung und Fertigung, hat sich bereits für die Herstellung einer Vielzahl von kieferorthopädischen Apparaturen als ernstzunehmende Alternative etabliert. Im Bereich der herausnehmbaren kieferorthopädischen Apparaturen beschränkt sich die CAD/CAM-Herstellung jedoch noch auf einzelne Berichte. Unter den herausnehmbaren Apparaturen nimmt der Funktionsregler Klasse 3 nach Fränkel (FR3) aufgrund seiner komplexen konventionellen Herstellung eine Sonderrolle ein. Daher ist seine fachgerechte Konstruktion bisher auf speziell ausgebildete Techniker limitiert, was seine Verbreitung erschwert. Als alternatives Konzept wird der FR3 in unserer Klinik mittlerweile mithilfe der CAD/CAM-Technik angefertigt und bei Patienten eingesetzt. Der Artikel soll einen Überblick über die Herstellung des CAD-FR3, seine technische Prüfung sowie die bisherigen klinischen Erfahrungen geben. Zudem präsentieren wir Beispiele für weitere herausnehmbare kieferorthopädische CAD/CAM-Apparaturen, welche in unserer Klinik stetig weiterentwickelt und geprüft werden.

Patient Compliance with Removable Orthodontic Retainers During Retention Phase: A Systematic Review

Article

Full-text available

Aug 2023

“Comparing the effectiveness, acceptability and oral hygiene status between vacuum formed retainer and Begg’s retainer”: a pilot study

Article

Full-text available

May 2023
BMC Oral Health

Abstract Background Recently, Vacuum formed retainers (VFRs) are preferred as an Orthodontic retention appliance over conventional Begg’s retainers. Very few studies have been conducted between VFRs and Begg’s retainers. Hence, this study aims at assessing the effectiveness, oral hygiene and acceptability between VFRs and Begg’s retainers with a follow up period of 1 year. Methods Eighty patients who completed fixed Orthodontic treatment were included. Retainers were delivered on the same day of debonding. Retainer 1/ R1 stands for VFRs and Retainer 2/ R2 stands for Begg’s retainers. The retainers were randomly allocated to both the arches. 40 VFRs and Begg’s retainers in maxillary and mandibular arch were given respectively. Effectiveness, oral hygiene condition were performed at T0 (After debonding), T1 (3 months after using retainers), T2 (6 months after using retainers), T3 (9 months after using retainers), T4 (12 months after using retainers) follow up stages, except the feedback form and the breakage of retainers that were filled at T4 stage. Results Both R1 and R2 retainers showed improvement in teeth alignment in both the arches at follow up stages. Interproximal contacts in maxillary and mandibular arch with VFRs and Begg’s retainers improved to 77.5% and 82.5% respectively. Considering the marginal ridge, Begg’s retainers and VFRs showed 95%, 55% increased proportion at T4 respectively (p

Evaluation of Water Sorption and Solubility and FTIR Spectroscopy of Thermoplastic Orthodontic Retainer Materials Subjected to Thermoforming and Thermocycling

Article

Full-text available

Apr 2023

Due to the fact that retainers are often recommended for a lifetime, their endurance and longevity are directly related to the quality of the materials used in their production. Our study examined the water sorption, water solubility, and Fourier transform infrared (FTIR) spectroscopy of six commercially available thermoplastic retainer materials (Essix Plus, Zendura, Duran Plus, Tru-Tain DX, Imprelon S pd, and Essix ACE). Moreover, this study evaluated the effect of thermoforming and thermocycling on the water sorption and solubility and surface molecular composition of the tested materials. The present study found that the type of retainer material affected water sorption and solubility capabilities. In addition, the aging methods employed significantly affected some retainer materials’ water sorption and solubility. Moreover, the surface molecular composition evaluated by FTIR spectroscopy revealed that most of the evaluated materials had similar FTIR spectra except for Zendura. All materials had a spectrum that resembled polyethylene terephthalate glycol (PETG) while Zendura had a spectrum similar to semi-rigid polyurethane (PU). Only Zendura had relatively unstable surface structural composition evaluated under the effects of (thermoforming and thermocycling) compared to all tested materials.

Direct 3D-Printed Orthodontic Retainers. A Systematic Review

Article

Full-text available

Apr 2023

Three-dimensional (3D) printing technology has shed light on many fields in medicine and dentistry, including orthodontics. Direct 3D-printed prosthetics, implants or surgical devices are well-documented. The fabrication of orthodontic retainers using CAD technology and additive manufacturing is an emerging trend but the available data are scarce. The research approach of the present review included keywords in Medline, Scopus, Cochrane Library and Google Scholar up to December 2022. The searching process concluded with five studies eligible for our project. Three of them investigated directly 3D-printed clear retainers in vitro. The other two studies investigated directly 3D-printed fixed retainers. Among them, one study was in vitro and the second was a prospective clinical trial. Directly 3D-printed retainers can be evolved over time as a good alternative to all the conventional materials for retention. Devices that are 3D-printed are more time and cost efficient, offer more comfortable procedures for both practitioners and patients and the materials used in additive manufacturing can solve aesthetic problems, periodontal issues or problems with the interference of these materials with magnetic resonance imaging (MRI). More well-designed prospective clinical trials are necessary for more evaluable results.

Evaluation of Mechanical Properties of Different Thermoplastic Orthodontic Retainer Materials after Thermoforming and Thermocycling

Article

Full-text available

Mar 2023

While the durability of thermoplastic aligners has been the subject of numerous studies, the durability of thermoplastic retainers has received significantly less attention. Patients are often advised to wear their thermoplastic retainers indefinitely, so the durability of the materials used in their fabrication is crucial to determining whether they are worth the cost. Limited studies have evaluated the properties of thermoplastic retainer materials and the effects of thermocycling on their mechanical properties. Thus, this study aimed to examine six thermoplastic retainer materials after thermoforming with and without thermocycling. The materials’ flexural modulus, hardness, and surface roughness values were measured after thermoforming (Group 1) and after thermoforming with subsequent thermocycling for 10,000 cycles (Group 2). After thermoforming, there was a significant difference in flexural modulus and hardness values between most of the materials. However, their surface roughness was not significantly different (p < 0.05). After thermocycling, the flexural modulus and hardness increased significantly for most tested materials (p < 0.05) compared to Group 1. Concerning the surface roughness, only two materials showed significantly higher values after thermocycling than Group 1. Thus, all the mechanical properties of the evaluated materials differed after thermoforming, except the surface roughness. Moreover, while thermocycling made the materials stiffer and harder in general, it also made some of them rougher.

The Influence of Different Cleaning Protocols on the Surface Roughness of Orthodontic Retainers

Article

Full-text available

Jan 2023

Thermoplastic materials are sensitive to humidity, temperature variations, enzyme activities , and cyclic loading. All these factors can cause changes to the mechanical properties of the material. The aim of this study was to determine the influence of different cleaning protocols on the surface roughness of orthodontic retainers. Samples of two brands of polyethylene terephthalate glycol (PET-G) material were exposed to four cleaning protocols: Corega (alkaline peroxide tablets), Toothbrush, Corega + toothbrush, Toothbrush + toothpaste, and Control. Measurement of the surface roughness of the sample on both the top and bottom side was carried out before and after cleaning. There was no statistical difference between the final values of the measured parameters. However, looking at the extent of the change in surface roughness, there was a statistically significant difference in the upper side of the Corega + toothbrush group between Materials A and B. This suggests that there was a greater change in the roughness of material A (Erkodur), given that the mean change in roughness of Material A was Ra 0.047, whereas the mean change in roughness of Material B was Ra 0.022. Almost all the tested cleaning procedures significantly increased the surface roughness of the PET-G retainer material. Of all the methods, the Corega tablets had the lowest influence on surface roughness.

Vacuum-Formed Retainers Versus Lingual-Bonded Retainers: A Systematic Review and Meta-Analysis of Stability of Treatment Outcomes in Orthodontically Treated Patients

Article

Full-text available

Jan 2022

Objective: This review aimed at analyzing the literature comparing vacuum-formed retainers and lingual-bonded retainers for maintaining treatment stability and periodontal health and evaluating retainer failure and patient satisfaction. Methods: Electronic databases such as PubMed, Cochrane Library, Ovid, Scopus, Web of Science, and Google Scholar were searched. Only randomized controlled trials were involved. Risk of bias was evaluated using Risk of Bias 2 Tool. Meta-analysis was performed and certainty of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation approach. Results: Five randomized controlled trials were included for qualitative analysis and 2 studies were included for quantitative analysis. Two studies concluded that lingual-bonded retainers were more effective than vacuum-formed retainers in maintaining treatment stability. Two studies had a high risk of bias and 3 studies had some concerns. No statistically significant difference in Little's Irregularity Index (standard mean difference = -0.10; P value = .61), inter-canine width (standard mean difference = 0.66; P value = .09), inter-molar width (standard mean difference = 0.08; P value = .85), arch length (standard mean difference = -0.18; P value = .60) between the 2 retainers was noted. Periodontal status and retainer failure rate (odds ratio= 2.28; P value = .23) were similar in both retainers. Patient discomfort, soreness, and speech difficulty were more with vacuum-formed retainers and oral hygiene maintenance was easier with vacuum-formed retainers. Conclusion: A very low-level certainty of evidence suggests that both vacuum-formed retainers and lingual-bonded retainers were equally effective in maintaining treatment stability. Periodontal status and retainer failures were similar in both retainers. Vacuum-formed retainers were better for oral hygiene maintenance but were associated with discomfort, soreness, and speech difficulty than lingual-bonded retainers.

Subjective Assessment of Bonded Fixed Lingual Retainers: A Questionnaire Survey

Article

Full-text available

Jan 2022

Aims This study aimed to assess the patients' subjective assessment of bonded fixed lingual retainers after completion of active orthodontic treatment. Objective A questionnaire comprising 11 questions evaluated the patients' experience with bonded fixed lingual retainer. Materials and Methods The content was validated by a group of seven experienced orthodontists. The questionnaire survey was run using Google Forms, responded by 45 (50.6%) males and 44 (49.4%) females between the ages ranging from 19 to 42 years. Their responses were rated on a Visual Analogue Scale as applicable. Cronbach's alpha test was utilised for assessing the reliability, and the Chi-square test was used for the quantitative variables. Results 33.7% of individuals were most comfortable, and 2.2% had severe discomfort during retainer placement. 6.6% of individuals had severe difficulty maintaining oral hygiene in the upper arch and 4.4% in lower teeth and gums, respectively. 2.2% had severe difficulty in speech. 85.4% had no tongue ulceration. 37.1% of respondents had a very good overall experience with fixed bonded lingual retainer, 59.5% had mild problems and only 1.1% had severe problems with a very bad experience. Conclusions The study concluded that the overall experience of respondents with fixed lingual bonded retainer had mild problems. It was comfortable for most of the patients in maintaining oral hygiene with mild difficulty in speech and chewing. The cause of failure of the retainer was mainly due to bond failure or broken wire in the retainer.

Orthodontic retention experience of university students: A qualitative study

Article

Nov 2022

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.

The Effects of Staining and Cleaning on the Color and Light Transmittance Changes of a Copolyester Retainer Material with Different Surface Textures

Article

Full-text available

Sep 2022

This study evaluated the efficacy of different cleaning methods with respect to changes in the color and light transmittance of both rough and smooth thermoformed, copolyester retainer specimens, after staining in different solutions. Four hundred copolyester sheets (Essix ACE) specimens were fabricated over molds with different surface textures, smooth and rough. The specimens were stained in four different solutions (n = 100 per solution) over 28 days; then, each of the four groups of 100 stained specimens was sub-divided into five groups of 20 specimens and subjected to a different destaining solution. The specimens were sub-divided with half subjected to an additional ultrasonic cleaning procedure. Light transmittance and color changes were analyzed using a spectrometer/integrating sphere assembly and a spectrophotometer. Mean difference comparisons were performed using appropriate statistical tests at p = 0.05. All five destaining solutions proved to be effective at removing coffee and tea stains. The surface roughness of the retainer material plays a significant role in the ability of cleaning solutions to remove stains, demonstrating a greater effect on cleaning rough specimens with respect to improvements in light transmittance and greater changes in color. Additionally, an ultrasonic cleaning unit generally enhanced the ability of all five solutions to clean the tea-stained specimens. However, the enhancements were only significant for light transmittance.

Retention in Orthodontics: A review

Article

Full-text available

Aug 2022

Skeletal and dental correction obtained by orthodontic treatment may tend to return to the pre-treatment state. This condition is defined as relapse. The retention phase applied after treatment is important to obtain stable results. Periodontium, soft tissue pressures, growth and occlusion are among the factors affecting stability. In the last decade, interest in retention procedures has increased and it has been found that retention regimes differ from country to country. Although retention affects nearly every patient, there is minimal agreement on the most appropriate approach to be taken in an individual case. The many variations of the retention procedure, the introduction of different materials for retention, or individual patient factors are among the reasons that lead to difficulties in selecting retention protocols. Basic retention protocol is provided with removable and fixed retention appliances. For removable retention, hawley, wraparound, vacuum formed retention appliance and positioners are used. For fixed retention, rigid steel retention wire bonded to terminal teeth or flexible retention wires bonded to all teeth between 3-3 can be preferred. NiTi retention wires produced with CAD / CAM technology are also among the current materials. While fixed retention appliances do not require patient cooperation, periodontal follow-up is recommended. Patient cooperation is needed for the use of removable retention appliances, but easy cleaning of removable appliances is an advantage. ‘Adjunct’ procedures may also be applied to the teeth or surrounding periodontium to assist the retention process. For example, it involves reshaping teeth such as interproximal reduction or circumferential supracrestal fiberotomy. In this review, information about retention is discussed in the light of current literature. How to cite this article: Seki Yurdakul M, Meriç P. Retention in Orthodontics: A review. Int Dent Res 2022;12(2):88-96. https://doi.org/10.5577/intdentres.2022.vol12.no2.7 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Comparison of Various Antimicrobial Agents for Thermoplastic Polymeric Retainers

Article

Full-text available

Sep 2022

The thermoplastic retainers indicated a rising incidence of cariogenic bacteria such as Streptococcus mutans. A report suggested the case of a patient with severe gingival inﬂammation and dental caries as a result of inadequate appliance cleaning. This study aims to compare the various antimicrobial agents for thermoplastic polymeric retainers. A minimum bactericidal concentration (MBC) of acetic acid was determined. Streptococcus mutans bioﬁlm was formed on punched 4-mm copolyester (Essix ACE ® ) and polyurethane (Vivera ® ) retainers after they were submerged in 0.12% chlorhexidine (CHX group), acetic acid (AA group), Polident Denture Cleanser ® (PD group), and Polident Pro Guard & Retainer ® (PR group). A crystal violet (CV) test was performed. The bioﬁlm imaging was assessed by confocal laser scanning microscopy (CLSM). The results showed that all chemical disinfectants exhibited statistically signiﬁcant differences (p < 0.05) compared to the positive control. This novel ﬁnding elucidated that 0.625% acetic acid is effective for antimicrobial in both copolyester and polyurethane retainers. However, only the CHX, PD, and PR groups could reduce bioﬁlm mass. In addition, the CV assay cannot provide information about the actual number of living and dead bacteria. Furthermore, the LIVE/DEAD BacLight assay was able to show the bacterial viability.

Impact of the Internal Structure Density in the Process of Fabrication of Orthodontic Master Models by Fused Deposition Modeling

Article

Full-text available

Jun 2022

The article focuses on the influence of infill (internal structure of components) in the dimensional accuracy of dental master models during the processes of their fabrication by Fused Deposition Modeling (FDM) technology, and their vacuuming process for production of clear orthodontic aligners. The components, in this case, were the upper jaws (maxillary teeth) of two individual patients (Tzina, Dimitris), which were obtained by intraoral 3D scanning. Patient Tzina at the time of intra-oral scanning was 27 years old and Dimitris was 23 years old. The method of 3D printing was the FDM, and the material used in this research was thermoplastic high impact polystyrene (HIPS). Three different percentages of infill density were set, 60%, 80%, and 100%. For each setting, there were five specimens (thirty 3D printed dental models in total, 15 for Tzina and 15 for Dimitris). After the 3D printing, the models were digitized and measured by GOM ATOS II Triple Scan MV 170 optical 3D scanner and compared with the values of the initial digital models. Then the dental master models underwent the process of Essix-aligners formation (single press) and were rescanned and measured again. The outcome of this research was to examine if the dental master models remain dimensionally accurate after these processes, and which infill provides the optimal and medically approved accuracy.

Post-treatment stability after 5 years of retention with vacuum-formed and bonded retainers—a randomized controlled trial

Article

Full-text available

Aug 2022

Background Retention after orthodontic treatment is still a challenge and more evidence about post-treatment stability and patients’ perceptions of different retention strategies is needed. Objectives This trial compares removable vacuum-formed retainers (VFR) with bonded cuspid-to-cuspid retainers (CTC) after 5 years of retention. Trial design A single centre two-arm parallel-group randomized controlled trial. Methods This trial included 104 adolescent patients, randomized into two groups (computer-generated), using sequentially numbered, opaque, and sealed envelopes. All patients were treated with fixed appliances in both jaws with and without tooth extractions. Patients in the intervention group received a VFR in the mandible (n = 52), and patients in the active comparator group received a CTC (n = 52). Both groups had a VFR in the maxilla. Dental casts at debond (T1), after 6 months (T2), after 18 months (T3), and after 5 years (T4) were digitized and analysed regarding Little’s Irregularity Index (LII), overbite, overjet, arch length, and intercanine and intermolar width. The patients completed questionnaires at T1, T2, T3, and T4. Results Post-treatment changes between T1 and T4 in both jaws were overall small. In the maxilla, LII increased significantly (median difference: 0.3 mm), equally in both groups. In the mandible, LII increased significantly in the group VFR/VFR (median difference: 0.6 mm) compared to group VFR/CTC (median difference: 0.1 mm). In both groups, overjet was stable, overbite increased, and arch lengths decreased continuously. Intercanine widths and intermolar width in the mandible remained stable, but intermolar width in the maxilla decreased significantly. No differences were found between groups. Regardless of retention strategy, patients were very satisfied with the treatment outcome and their retention appliances after 5 years. Limitations It was not possible to perform blinded assessments of digital models at follow-up. Conclusions Post-treatment changes in both jaws were small. Anterior alignment in the mandible was more stable with a bonded CTC retainer compared to a removable VFR after 5 years of retention. Patients were equally satisfied with fixed and removable retention appliances. Trial registration ClinicalTrials.gov (NCT03070444).

Assessment of the Bacterial Loads of Vacuum-Thermoformed Removable Retainers (VTRR) in Patients under Retention Therapy: A Randomized Clinical Trial

Article

Full-text available

Jul 2022

Retention devices are essential after orthodontic treatment in order to avoid the risk of relapse. For this goal, vacuum-thermoformed removable retainers (VTRRs) are useful tools in clinical practice. The main limitation related to them is the accumulation of plaque. The aim of this study was to investigate the bacterial loads present on VTRRs (Essix ACE Plastic, Dentsply Sirona) in patients under retention therapy. Patients were randomly divided into three groups, depending on the product used for the cleansing of the VTRR: Geldis, Polident tablets, and simple water, respectively. Microbiological samples were taken from the retainers at the baseline, after 1 and after 2 months, with the collection of Bleeding on Probing (BoP), Plaque Index (PI), Basic Erosive Wear Examination (BEWE) and Schiff Air Sensitivity test (SAI). A total of 15 patients were recruited and for each product, 5 patients were allocated. No significant intragroup and intergroup differences were observed at any time point for PI, SAI, BoP, Red Complex, Total Pathogen and Total Saprophyte loads. A significant intragroup and intergroup difference was assessed at T1 and T2 for BEWE in the control group. According to the results of this study, the bacterial load on VTRR retainers is not influenced by the cleaning methods tested.

A Comparison of Preoperative and Postoperative Anxiety Levels Affecting Preoperative and Postoperative Processes of Orthopedics Patients

Article

Full-text available

Jun 2022

Objective: Different anxiety levels come up, and many of the patients become worried before operations. If there was anxiety, the patients should be relieved by diagnosing, and the negative anxiety should be turned into a positive form. It will cause positive reactions of the patients and make the treatment gains increase. We aimed to compare the anxiety levels of the patients about the orthopedic operations according to the sex, age, and education levels of the patients. Materials and Methods: 122 patients who underwent knee arthroscopy under spinal anesthesia in the Orthopedics and Traumatology operating room were included in the study. Patients aged between 18-55 years, included in ASA I and II classes, literate, not having any psychiatric and neurological problems, not using psychiatric drugs, and not using chronic alcohol, were included in the study. The patients anxiety levels were checked before and after surgery using the State-Trait Anxiety Inventory Test (STAI TX-1 Anxiety Skala). Results: It was found that there was no significant difference between the patients pre and post-test state anxiety levels; however, the post-tests put forward that the patients state anxiety levels after the operation were a little higher than their pre-tests state anxiety levels before the operations. Conclusion: The patients should be informed about the problems, limitations, advantages, and disadvantages of the operation before and after the procedure. The patients should also be given psychological support to decrease their anxieties about the surgical procedure.

A novel ‘stop-hole’ strategy to extend the fatigue life of orthodontic thermoformed retainers: an in vitro study

Article

Nov 2024

Objectives This study aimed to investigate the potential to limit crack propagation in thermoformed retainers (TRs) and extend their fatigue life by placing a ‘stop-hole’. Methods Thirty-two TRs, fabricated from 1 mm thick, round polyethylene terephthalate glycol (PETG) blanks of ICONIC®, underwent testing within a custom-built fatigue tester. After initial crack growth of 3 mm, the TRs were divided into three groups: a control group (C) and two experimental groups based on the stop-hole placement method. In the first experimental group, stop-holes were placed using a 1 mm round carbide bur on a slow-speed handpiece (ES), while the second group utilized a heated 1-mm-width ball-ended CPITN probe (EH). Following the placement of a stop-hole at the crack-tip, all 32 TRs resumed testing until the final crack length of 10 mm was reached. Results Stop-hole placement significantly prolonged the delay in crack re-initiation in both experimental groups compared to the control group (P < .001 for both). The mean re-initiation times for the ES and EH groups were 104.50 and 129.50 min, respectively, whereas the control group was 28.94 min. Consequently, this discrepancy was reflected in the total testing times, with both experimental groups requiring significantly longer time to reach the final crack length (P < .001). There was no significant difference in the testing times between the two experimental groups. Limitations This is an in vitro study. Conclusions The stop-hole methodology significantly extended the fatigue life of a TR in a controlled laboratory environment.

Can vacuum-formed retainers maintain arch dimensions and alignment compared to Hawley and fixed bonded retainers after treatment with fixed appliances? A systematic review and meta-analysis

Article

Aug 2024
EUR J ORTHODONT

Umar Hussain

Background Different types of retention appliances have been proposed over the years, but their effectiveness in maintaining arch dimensions and alignment after orthodontic treatment is still unclear. Aim To assess the efficacy of vacuum-formed retainers (VFRs) in preserving arch widths, arch length, and anterior alignment in maxillary and mandibular arches, compared to removable Hawley retainers (HRs) or fixed bonded retainers (FBRs). Search methods: unrestricted literature search of five major databases up to March 2024. Selection criteria randomized/non-randomized clinical studies comparing VFRs to removable HRs or FBRs. Data collection and analysis after duplicate study selection, data extraction, and risk of bias assessment, random effects meta-analyses of standardized mean differences and their 95% confidence intervals were performed, followed by meta-regressions, sensitivity analyses, and assessment of the quality of evidence with GRADE. Results Twenty-two prospective studies (4 non-randomized and 18 randomized controlled trials) involving 1797 patients (mean age 17.01 years, 38.3% males) were included. No significant differences were found in the intercanine width, intermolar width, and arch length between VFRs and HRs, in both arches (P > 0.05). However, VFRs were statistically more effective than HRs in terms of Little’s irregularity scores (LII) in the maxilla (eight studies; SMD = −0.42; 95% CI: −1.03 to −0.09; P = 0.02; I2 = 73.4%) but not in the mandible (P = 0.12). No significant differences were reported for all considered outcomes between VFRs and FBRs in in both arches (P > 0.05), except for lower LII, where VFRs were significantly less efficient (eight studies; SMD = 1.49; 95% CI = 0.26–2.7; P = 0.02; I2 = 93%). Follow-up times, risk of bias, and wire type (of FBRs) did not show statistically significant effects on outcome variables. Sensitivity analyses showed robustness of the findings for including non-randomized and postretention studies. The certainty in these estimates was from moderate to low due to the risk of bias and inconsistency. Conclusions Low to moderate quality evidence indicates that VFRs are as effective as HRs in maintaining arch widths, length, and alignment. Low-quality evidence found similar efficacy between VFRs and FBRs, with FBRs being statistically more effective at maintaining lower arch alignment, but the difference was not clinically significant.

Poly-Ether-Ether-Ketone (PEEK) Versus Dead-soft Coaxial Bonded Retainers: A Randomized clinical Trial. Part 1: Stability, retainer failure, and participant satisfaction

Article

Aug 2024

Background Poly-ether-ether-ketone (PEEK) was introduced in dentistry as an alternative to metal alloys. Objective To assess the effectiveness of PEEK-fixed retainers in preserving the stability of mandibular anterior and participant satisfaction as compared to the Dead-soft coaxial fixed retainer (DSC). Trial design A single-centre, two-arm parallel groups randomized clinical trial. Methods The patients treated with pre-adjusted orthodontic appliances who have a Little’s Irregularity Index (LII) ≤ 0.5 mm have been enrolled in the trial. PEEK retainers were prepared to round 0.8 mm wire by computer-aided design and manufacturing, and the DSC wire was carefully adapted to the lingual surface of the lower anterior teeth. The primary outcome was the stability of lower anterior teeth as assessed by LII, while the secondary outcomes were changes in occlusal parameters, retainer failure, and patient satisfaction. The data were collected at the debonding stage (T0), 1 month (T1), 3 months (T3), and 6 months (T6) after starting the trial, except for patient’s satisfaction, which was recorded using an electronic form at T1 and T6. Blinding Single blinding of participants. Results A total of 46 participants with an age range of 12–28 years old were randomly allocated to the two groups (n = 23 in each). Only one participant dropped out; therefore, 45 participants were analysed. The DSC group showed a significant increase in LII at T3. Both retainer groups had comparable occlusal measurements, failure frequency, and survival time, with no significant difference. The patients in the DSC group reported a statistically significant perception of change in the position of their teeth compared to those in the PEEK group. Harms No harmful effects have been reported. Limitations Limited follow-up duration and the inability to blind the operator due to the nature of the intervention. Conclusions After 6-month retention, the PEEK retainer was equally effective to DSC retainers in maintaining the teeth alignment, with no significant differences regarding the failure frequency, survival rate, and general patient satisfaction. Trial registration https://register.clinicaltrials.gov. (NCT05557136).

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

Article

Full-text available

Jul 2024

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. Keywords: Orthodontic appliance design; Orthodontics, corrective; Speech; Speech sound disorder

Difference in acceptance and satisfaction perception on the use of Hawley and vacuum-formed retainers among post-orthodontic patients

Article

Jul 2024

Objectives It has been observed that using a retainer during the retention phase of orthodontic treatment can result in various patient perceptions; however, only limited research exists concerning it. Therefore, the present research studies and analyzes the differences in acceptance and satisfaction perception between patients who use two types of removable retainers: Hawley retainers (HRs) and vacuum-formed retainers (VFRs). Material and Methods This research comprised 80 participants ( n per group = 40). Eligible individuals who had finished treatment between 6 months and 5-years-prior and met the inclusion criteria were contacted to partake in this study. The participants were asked to complete a digital-based questionnaire consisting of seven questions. Each patient was asked the questions twice, once for maxillary and once for mandibular retainers. The visual analog scale was used to measure their responses. Blinding was implemented to minimize potential bias during data analysis. Results Statistically significant differences were found in the speaking ability and positive comments received with maxillary retainer in place. Statistically significant differences were not found in the perception of adaptation, cleaning ability, negative comments received, and overall retainers’ acceptance and patients’ satisfaction with both retainers in place, as well as the speaking ability and positive comments received with the mandibular retainer. During the study, no harm was observed in any of the patients. Conclusion VFRs cause less speech difficulty and elicit more positive comments on the maxilla than HRs. No significant differences were found between HRs and VFRs concerning the perception of adaptation, cleaning ability, negative comments received, and overall retainers’ acceptance and patients’ satisfaction with both retainers in place. Moreover, no differences were found between patients’ speaking ability and positive comments received with the mandibular retainer.

Environmental sustainability of post-orthodontic dental retainers: a comparative life-cycle assessment of Hawley and Essix retainers

Article

Mar 2024

Background Environmental sustainability has been brought into the limelight due to the global climate crisis. This crisis is driven by human activities and even the healthcare sector is no exception. Within dentistry, orthodontics is a large global market; hence, the use of post-orthodontic retainers has a significant environmental footprint. The aim of this study was to determine the environmental sustainability of post-orthodontic retention using Hawley and Essix retainers. Materials and methods A comparative life-cycle assessment (LCA) was carried out to compare the environmental impact of both retainers. All inputs and outputs were accounted for using the Ecoinvent database, v3.7.1, and openLCA software. Sixteen impact categories were used to determine their environmental burden. Results Of the 16 impact categories, the Hawley had a greater environmental burden than the Essix retainer in 12 categories. The Hawley’s most significant contributors to its impact values are factory manufacturing and in-house production, with an average of 41.45% and 52.52%, respectively. For the Essix, the greatest contributor is factory manufacturing, with an average of 64.63%. However, when factoring in the lifespan of the retainers, the Essix would have a greater environmental impact than the Hawley retainer. Limitations This study employed a comparative LCA. There were also assumptions made, but these were supported by research. Conclusions On the basis of the evidence gathered in this study, Hawley retainers are more environmentally sustainable than Essix retainers. These results would better enable clinicians to factor in the environmental impact and make informed decisions on the choice of retainer type.

Different Perception on the Use of Hawley and Vacuum-formed Retainers Amongst Post-orthodontic Patients. Part 1: Discomfort and Aesthetic Perception

Article

Jan 2024

Backgrounds and Objectives: The use of a retainer in the retention phase creates different perceptions amongst patients. However, the evidence regarding it is limited. This research was conducted to analyze the difference in patients&’ perception of discomfort and aesthetics between Hawley and vacuum-formed retainers. Methods: This study included 80 patients ( n per group = 40). Patients were invited to participate if they had completed their treatment for 6 months to 5 years and complied with the inclusion criteria. Seven questions were given to the patients using a digital-based questionnaire. Each was asked twice to address both maxillary and mandibular retainers. Responses were measured using the Visual Analogue Scale. Blinding was applied through data analysis. Results: Statistically significant differences were found in the perception of the aesthetic, shape, and retainer color. Statistically significant differences were not found in the perception of comfort, pain, sharpness, pressure, presence of soft tissue cut, and confidence level with the retainer in place. No harm was observed to any patients during the study. Conclusions: Vacuum-formed retainers (VFRs) were more acceptable than Hawley retainers (HRs) regarding the retainer&’s aesthetic, shape, and color. There were no significant differences between HRs and VFRs regarding patient perception of discomfort and confidence when using the retainer.

Patients’ perception of orthodontic retainers: a systematic review

Article

Dec 2023

Background Orthodontic retainers are widely used to prevent relapses after orthodontic treatment; however, evidence about patients' perceptions of retainers is lacking. Objective To assess patients’ perception of orthodontic retainers. Search Methods PubMed, Web of Science, Scopus, LILACS, LIVIVO, Cochrane Library, and gray literature (Google Scholar) were searched without date or language restrictions. A manual search of the reference lists of the included articles was also performed. Selection criteria Studies comparing patients’ perceptions of wearing orthodontic retainers were included. Data collection and analysis According to the study design, the risk of bias (RoB) assessment was performed using RoB 2.0 or ROBINS-I. The level of evidence was assessed through the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) tool. Results Seventeen studies met the eligibility criteria. After the RoB assessment, 12 randomized controlled trials presented a high RoB, and 4 non-randomized controlled trials presented a moderate RoB. The certainty of evidence was classified as very low for the four assessed outcomes. The studies generally reported an initial temporary negative impact of orthodontic retainers. Different esthetic, functional, and ease-of-use advantages are reported using removable and fixed retainers. A quantitative analysis was not performed due to the considerable clinical and methodological heterogeneity among the studies. Conclusion The current evidence, although very limited, suggests that orthodontic retainers have an initial negative impact related to discomfort and functional limitations, but they seem to regress over time. There is a preference for thermoplastic over Hawley-type retainers. However, thermoplastic retainers cause different functional difficulties, and bonded retainers present the advantage of affecting speech function less than orthodontic removable retainers, although they can facilitate oral hygiene problems. Registration PROSPERO (CRD42022306665).

ORTHODONTIC RETENTION- A REVIEW.

Article

Feb 2022

After the teeth have been corrected orthodontically and malocclusion has been relieved the job of orthodontist is not over. The active phase of treatment is to be followed up with a passive phase in which corrected positions of teeth needs to be maintained after treatment and is often the most challenging part of an orthodontic treatment plan. Hence, a phase of retention is normally required after orthodontic tooth movement which may be in the form of removable or fixed retainer wear. In this review article, we have discussed about the importance of retention protocols and patient education regarding the same to ensure that the patient is in the know how of the care that is expected from him at the end of the active orthodontic phase.

Comparison of Light Transmittance and Color Changes between Polyurethane and Copolyester Retainer Materials after Staining and Destaining.

Preprint

Full-text available

Sep 2023

Background Retainers are the only effective approach to prevent orthodontic relapse. The aim of this study was to compare the changes in color and light-transmittance of rough and smooth thermoformed polyurethane and copolymer retainer samples after staining in different solutions and destaining with different approaches. Methods Four hundred copolyester (Essix® ACE) and 400 polyurethane (Zendura®) samples with different surface textures, smooth and rough, were stained in 4 different solutions (n = 100 per solution) over 28 days. Each of the four groups of 100 stained samples of each material was subdivided into 5 groups of 20 samples and subjected to different destaining solutions. Light transmittance and color changes were evaluated using a spectrometer and a spectrophotometer. Mean differences were compared using appropriate statistical tests at P = 0.05. Results No significant differences in light transmittance were found between both untreated materials. Both materials were stained in a similar fashion and showed no significant differences between two materials. Coffee and tea stained both materials more significantly than wine, but there was a significant difference of changes of color and light transmittance between rough and smooth surfaces during the destaining in coffee- and tea-stained samples of copolyester material. All destaining solutions were effective at removing all stains on the samples. The surface roughness of the material plays a significant role in the ability of the materials to be destained, demonstrating a more significant greater effect on cleaning rough samples for improvements in light-transmittance and greater changes in color. Conclusions This study concluded that the surface of materials plays a significant role in the material destaining and staining. In addition, the different polymer used for retainer fabrication exhibited different responses during the destaining process depending on types of stains.

The Effects of Fixed Versus Removable Orthodontic Retainers on Stability and Periodontal Health: 4-Year Follow-Up of a Randomized Controlled Trial

Article

Jul 2023

Introduction: Long-term or even indefinite retention is routinely prescribed after orthodontic treatment as a preventive safeguard against post-treatment changes induced by tooth movement, physiological healing, and the aging process. Though both fixed and removable versions of retainers may be equally effective in terms of results, sufficient research to support this assumption is missing at the moment. Objectives: Long-term effects of fixed and removable retention on the periodontium, and the compliance level when used for an extended period of time. Methods: For 4 years participants were given a supply of canine-to-canine retainers and vacuum-formed canine-to-canine retainers. The inter-canine, as well as inter-molar widths, the length, and the extraction space opening of the mandibular anterior portion, were measured. Gingival inflammation, calculus, and plaque were observed, as well as the attachment of clinical and the case of bleeding during probing. 42 members had returned in the follow-up period, with 21 from each of the two groups. Measurements of the modified gingival index and plaque scoring were performed on the 10 intra-oral photographs that were taken at 4-week intervals in this study to investigate the intra-examiner reliability. Results: After controlling for confounding variables, there was a 1.64 mm (95% confidence interval [CI], 0.30, 2.98 mm) median between-groups difference among patients who utilized vacuum-formed retainers (VFRs). The treatment groups did not vary in inter-canine and intermolar widths (P = 0.52; 95% CI, -1.07, 1.05), arch length (P = 0.99; 95% CI, -1.15, 1.14), or opening of extraction spaces (P = 0.84). Conclusion: A long-term study demonstrates that fixed retention can preserve the alignment of the mandibular anterior over time for the first time. Gingival discomfort and higher plaque scores were reported in both types of retainers.

Planets of orthodontics volume 4

Book

Full-text available

Jun 2023

Haris Khan

PLANETS OF ORTHODONTICS- Orthodontic Appliances

Book

Full-text available

Aug 2022

Mohammed Almuzian

Compliance with retainer wear using audiovisual integration and reminder: a randomized clinical trial

Article

Full-text available

May 2023

Active audiovisual representation of instructions ensures vibrant knowledge acquisition and improves acquaintance needed for self-care with retainer wear. The aim of this trial is to assess the impact of audiovisual instructions with additional weekly electronic reminder messages on improving adherence to instructed wear time of Hawley retainer, periodontal outcomes, and participants’ experiences. Fifty-two participants (mean age 26.1 y) planned for removable retention, were randomly assigned to two parallel groups to receive either (1) audiovisual instructions with an additional weekly reminder, or (2) verbal instructions alone. Each participant received a Hawley retainer equipped with a TheraMon microsensor and was instructed to wear it for 22 h daily. Participants were monitored for adherence to the wear time after 3 (T1) and 6 months (T2), and had their periodontal health and experiences assessed at T2. Overall, the mean objectively measured daily wear time at T1 was 14.9 (± 4.9 h), and 14.3 (± 5.4 h) at T2. After 3 months, no significant differences were found between the groups (p = 0.065), however, a significant difference favoring better compliance with wear instructions was observed in the audiovisual group after 6 months (p = 0.033). A non-significant difference was observed between both groups regarding the gingival (p = 0.165) and plaque index scores (p = 0.173). Participants’ experiences were similar in both groups, except for satisfaction with the way of delivering instructions, being favorably reported in the audiovisual group. Audiovisual instructions with weekly reminders seem to have a significant effect on patient compliance in the longer term. Trial registration: TCTR20230220002.

Retention procedures for stabilising tooth position after treatment with orthodontic braces

Article

May 2023
COCHRANE DB SYST REV

Background: Without a phase of retention after successful orthodontic treatment, teeth tend to 'relapse', that is, to return to their initial position. Retention is achieved by fitting fixed or removable retainers to provide stability to the teeth while avoiding damage to teeth and gums. Removable retainers can be worn full- or part-time. Retainers vary in shape, material, and the way they are made. Adjunctive procedures are sometimes used to try to improve retention, for example, reshaping teeth where they contact ('interproximal reduction'), or cutting fibres around teeth ('percision'). This review is an update of one originally published in 2004 and last updated in 2016. Objectives: To evaluate the effects of different retainers and retention strategies used to stabilise tooth position after orthodontic braces. Search methods: An information specialist searched Cochrane Oral Health Trials Register, CENTRAL, MEDLINE, Embase and OpenGrey up to 27 April 2022 and used additional search methods to identify published, unpublished and ongoing studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) involving children and adults who had retainers fitted or adjunctive procedures undertaken to prevent relapse following orthodontic treatment with braces. We excluded studies with aligners. Data collection and analysis: Two review authors independently screened eligible studies, assessed risk of bias and extracted data. Outcomes were stability or relapse of tooth position, retainer failure (i.e. broken, detached, worn out, ill-fitting or lost), adverse effects on teeth and gums (i.e. plaque, gingival and bleeding indices), and participant satisfaction. We calculated mean differences (MD) for continuous data, risk ratios (RR) or risk differences (RD) for dichotomous data, and hazard ratios (HR) for survival data, all with 95% confidence intervals (CI). We conducted meta-analyses when similar studies reported outcomes at the same time point; otherwise results were reported as mean ranges. We prioritised reporting of Little's Irregularity Index (crookedness of anterior teeth) to measure relapse, judging the minimum important difference to be 1 mm. Main results: We included 47 studies, with 4377 participants. The studies evaluated: removable versus fixed retainers (8 studies); different types of fixed retainers (22 studies) or bonding materials (3 studies); and different types of removable retainers (16 studies). Four studies evaluated more than one comparison. We judged 28 studies to have high risk of bias, 11 to have low risk, and eight studies as unclear. We focused on 12-month follow-up. The evidence is low or very low certainty. Most comparisons and outcomes were evaluated in only one study at high risk of bias, and most studies measured outcomes after less than a year. Removable versus fixed retainers Removable (part-time) versus fixed One study reported that participants wearing clear plastic retainers part-time in the lower arch had more relapse than participants with multistrand fixed retainers, but the amount was not clinically significant (Little's Irregularity Index (LII) MD 0.92 mm, 95% CI 0.23 to 1.61; 56 participants). Removable retainers were more likely to cause discomfort (RR 12.22; 95% CI 1.69 to 88.52; 57 participants), but were associated with less retainer failure (RR 0.44, 95% CI 0.20 to 0.98; 57 participants) and better periodontal health (Gingival Index (GI) MD -0.34, 95% CI -0.66 to -0.02; 59 participants). Removable (full-time) versus fixed One study reported that removable clear plastic retainers worn full-time in the lower arch did not provide any clinically significant benefit for tooth stability over fixed retainers (LII MD 0.60 mm, 95% CI 0.17 to 1.03; 84 participants). Participants with clear plastic retainers had better periodontal health (gingival bleeding RR 0.53, 95% CI 0.31 to 0.88; 84 participants), but higher risk of retainer failure (RR 3.42, 95% CI 1.38 to 8.47; 77 participants). The study found no difference between retainers for caries. Different types of fixed retainers Computer-aided design/computer-aided manufacturing (CAD/CAM) nitinol versus conventional/analogue multistrand One study reported that CAD/CAM nitinol fixed retainers were better for tooth stability, but the difference was not clinically significant (LII MD -0.46 mm, 95% CI -0.72 to -0.21; 66 participants). There was no evidence of a difference between retainers for periodontal health (GI MD 0.00, 95% CI -0.16 to 0.16; 2 studies, 107 participants), or retainer survival (RR 1.29, 95% CI 0.67 to 2.49; 1 study, 41 participants). Fibre-reinforced composite versus conventional multistrand/spiral wire One study reported that fibre-reinforced composite fixed retainers provided better stability than multistrand retainers, but this was not of a clinically significant amount (LII MD -0.70 mm, 95% CI -1.17 to -0.23; 52 participants). The fibre-reinforced retainers had better patient satisfaction with aesthetics (MD 1.49 cm on a visual analogue scale, 95% CI 0.76 to 2.22; 1 study, 32 participants), and similar retainer survival rates (RR 1.01, 95% CI 0.84 to 1.21; 7 studies; 1337 participants) at 12 months. However, failures occurred earlier (MD -1.48 months, 95% CI -1.88 to -1.08; 2 studies, 103 participants; 24-month follow-up) and more gingival inflammation at six months, though bleeding on probing (BoP) was similar (GI MD 0.59, 95% CI 0.13 to 1.05; BoP MD 0.33, 95% CI -0.13 to 0.79; 1 study, 40 participants). Different types of removable retainers Clear plastic versus Hawley When worn in the lower arch for six months full-time and six months part-time, clear plastic provided similar stability to Hawley retainers (LII MD 0.01 mm, 95% CI -0.65 to 0.67; 1 study, 30 participants). Hawley retainers had lower risk of failure (RR 0.60, 95% CI 0.43 to 0.83; 1 study, 111 participants), but were less comfortable at six months (VAS MD -1.86 cm, 95% CI -2.19 to -1.53; 1 study, 86 participants). Part-time versus full-time wear of Hawley There was no evidence of a difference in stability between part-time and full-time use of Hawley retainers (MD 0.20 mm, 95% CI -0.28 to 0.68; 1 study, 52 participants). Authors' conclusions: The evidence is low to very low certainty, so we cannot draw firm conclusions about any one approach to retention over another. More high-quality studies are needed that measure tooth stability over at least two years, and measure how long retainers last, patient satisfaction and negative side effects from wearing retainers, such as tooth decay and gum disease.

Wear and fatigue resistance: An in-vitro comparison of three polyethylene terephthalate glycol and thermoplastic polyurethane materials for vacuum-formed retainers

Article

Mar 2023

Objective: To test the wear and fatigue resistance of three materials (Essix ACE®, Taglus®, and Zendura A®) for the fabrication of vacuum-formed retainers in an artificial oral environment. Material and methods: Wear resistance was tested by subjecting 21 retainers of each Essix ACE®, Taglus®, and Zendura A® to 12,000 wear cycles at 75N to simulate one year of retainer wear with moderate nighttime bruxing. Post-wear retainer thickness was compared to baseline measurements to calculate wear depth. Fatigue resistance was tested by flexing 15 retainers of each material at an angle of 25 degrees for 1,825 cycles to simulate one year of removing and reinserting a retainer five times per day. Retainers were visually inspected for fractures. Pairwise t-tests with correction using Tukey's method were used to determine significant differences between materials. Results: The mean wear depths were 0.155±0.021mm, 0.168±0.031mm, and 0.096±0.033mm for Essix ACE®, Taglus®, and Zendura A®, respectively. The wear depth of Zendura A® was significantly lower than that of both Essix ACE® (P<0.001) and Taglus® (P<0.001). There was no significant difference in wear depth between Essix ACE® and Taglus® (P=0.312). Under the parameters set for the fatigue resistance test, fractures did not occur on any of the tested materials. Conclusions: Under the assumption of moderate nighttime bruxing for one year, Zendura A® is the most wear-resistant among the materials tested. With the assumption of retainer removal and reinsertion five times per day for one year, all three materials tested have the same ability to resist fatigue.

Retention

Chapter

Mar 2023

Maintaining post-orthodontic outcomes is one of the most challenging aspects for the orthodontist. As the teeth tend to move to their pre-treatment position, a basic understanding of mechanisms and etiology of relapse is essential for the orthodontist. Several factors are involved in the etiology of relapse, such as inappropriate retention appliance, the retention protocol of the orthodontist, the soft tissue relapse, and the occlusal and growth changes. Patient preference and compliance with the appliance is also a key factor for the success of orthodontic retention. This chapter aims to answer important questions related to the need for orthodontic retention, the retention protocols, the effectiveness of orthodontic retainers, and common problems of retainers. Different factors may play a role in the retention phase and it would be also investigated in this chapter.

Comparison of 2 different wear protocols of vacuum-formed retainers with respect to the conventional parameters and 3-dimensional superimpositional analysis

Article

Mar 2023

Introduction: This study aimed to compare the effectiveness of 2 different wear protocols of vacuum-formed retainers (VFR) in terms of angular and linear displacement of teeth using 3-dimensional (3D) superimpositional analysis and conventional model parameters. Methods: The study was conducted on 2 groups, each consisting of 17 patients randomly assigned to the part-time group or full-time group of VFR wearing after a nonextraction treatment. While conventional model measurements were assessed on 3D dental casts, 3D tooth movements were evaluated by digitally superimposed scans of casts acquired at 4-time points (debonding and 1, 3, and 6 months after debonding). Regarding conventional parameters, the difference between time-dependent changes among the groups was tested using the nonparametric Brunner-Langer and parametric linear mixed models. Considering 3D measurements, comparisons of groups were made using the Student t tests. Results: There were no significant intergroup differences regarding conventional model parameters at any time (P >0.05). Significant intergroup differences were observed regarding angular and linear relapses in the labiolingual direction for maxillary and mandibular incisors, as well as the rotational relapses for maxillary left canine and mandibular right lateral incisor, which were greater in the part-time group in the first month and at the end of 6 months (P <0.05). Conclusions: Conventional model parameters appear to play a debatable role in evaluating the effectiveness of a retainer wear regimen. Three-dimensional analysis of tooth movements revealed that part-time VFR wear was less effective in retaining labiolingual and rotational tooth movements for the first month after debonding.

DJIGIMS Journal

Article

Full-text available

Nov 2022

The Use of Dental Patient-Reported Outcomes Among Randomized Controlled Trials in Orthodontics: A Methodological Study

Article

Oct 2022
J Evid Base Dent Pract

Objective : To identify and summarize the use and characteristics of dental patient-reported outcomes (dPROs) and dental patient-reported outcome measures (dPROMs) within randomized controlled trials (RCTs) published in 5 leading orthodontic journals. Methods : A manual search was conducted to identify intervention (therapeutic or preventive) related RCTs published in selected journals between 2015 and 2021. Two authors extracted the characteristics of each included trial, as well as all outcomes and outcome measures used in these trials independently and in duplicate. Thereafter, the use of dPROs and dPROMs was identified and summarized. We classified all dPROs into 2 general types (oral health-related quality of life [OHRQoL] and others) and dPROMs into 3 categories (single-item questionnaires, generic multiple-item questionnaires, and specific multiple-item questionnaires). We also identified whether these dPROMs assessed 4 dimensions of OHRQoL (Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact). Results : From 4631 examined articles, a total of 315 RCTs were included, of which 76 (24.1%) used dPROs and dPROMs. Eight different dPROs (OHRQoL, patients’ satisfaction with treatment, difficulty, compliance, preference, efficacy, duration, and unwanted events) and 34 different dPROMs (including 13 single-item questionnaires, 7 generic multiple-item questionnaires, and 14 specific multiple-item questionnaires) were identified in these trials. OHRQoL was the most commonly used dPRO (n=71; 93.4%), followed by patients’ satisfaction with treatment (n=10; 13.2%), patient-reported difficulty (n=5; 6.6%), and patient-reported compliance (n=4, 5.3%). The 4 most frequently used dPROMs were pain measured with 10mm Visual Analogue Scale (n=20; 24.1%), pain measured with Numerical Rating Scale (n=11; 13.3%), the Feldmann's Questionnaire (2007) (n=6; 7.2%), and the Oral Health Impact Profile 14 (n=5; 6.0%). Conclusion : Only about one-fourth of RCTs published in leading orthodontic journals can reflect patients’ perspectives. OHRQoL was the most commonly used dPRO in these trials. Substantial heterogeneity exists among dPROMs used for OHRQoL assessment. Efforts are needed from researchers, reviewers, editors and other stakeholders to promote the wide and standardized use of dPROs in orthodontic research.

The Interesting Types of Plastic of Invisible Retainers

Article

Sep 2022

Kanket Kiatwarawut

A Guide to Orthodontic Devices for Trainees in Orthognathic Surgery

Article

Jul 2022

Purpose Despite the interplay between orthodontics and orthognathic surgery, trainees in plastic surgery and oral and maxillofacial surgery do not receive formal training in orthodontics and associated hardware. This study aims to help surgical trainees better understand the role of orthodontic treatment in achieving enhanced dental occlusion and alignment and optimize surgical decision making. Methods A review of recent literature was conducted to consolidate current practices for the use of orthodontic devices commonly used in orthognathic surgical patients. Results Orthodontic treatments may be preventive, interceptive, and/or corrective. Braces and clear aligners are popular devices used to correct tooth positioning via 3 orders of control: first (“in-out” and rotation), second (mesio-distal angulation or “tip”), and third order (inclination or torque). Further, various treatments exist for skeletal and dental malocclusions, which may occur in transverse (crossbites, narrow arches) and/or sagittal (over/underbites) planes. Palatal expanders such as the Hyrax or Haas assist in correction of transverse deficiencies. Appliances for sagittal corrections typically take advantage of patient’s remaining growth and include a variety of headgear types (cervical, high-pull, occipital, reverse-pull), functional appliances (fixed or removable), or simply the use of interdental elastics. Conclusion As patients are increasingly seeking orthodontic care in conjunction with surgery, it is important for surgical trainees to develop a strong understanding of the various orthodontic devices used.

Oral surgery: The cost, effectiveness and cost effectivenes of removal and retention of asymptomatic, disease free third molars

Article

Full-text available

Oct 1999

Purpose of investigation The study was undertaken to identify the least costly, most effective and most cost-effective management strategy for asymptomatic, disease free mandibular third molars.

Economic Evaluation of Dental Sealant and Fluoride Mouthrinsing Program in Two Non Fluoridated Regions of Victoria

Article

Full-text available

Oral surgery: The cost, effectiveness and cost effectivenes of removal and retention of asymptomatic, disease free third molars

Article

Full-text available

Nov 1999

The study was undertaken to identify the least costly, most effective and most cost-effective management strategy for asymptomatic, disease free mandibular third molars. A decision tree model of the outcomes of mandibular third molar retention and removal was constructed. Probability data for possible outcomes were obtained from a comprehensive literature review and entered into the decision tree. The cost to the NHS in treating each outcome was calculated. 100 patients attending the oral surgery clinics, University of Wales Dental Hospital rated the effect of each outcome on their own life. The cost and effectiveness data for each outcome were entered into the decision tree and the analyses were conducted by 'folding back' the decision tree based on the probabilities. Mandibular third molar retention was less costly (170 Pounds), more effective (69.5 effectiveness units on a 100 point scale) and more cost-effective (2.43 Pounds per unit of effectiveness) than removal (226 Pounds, 63.3 and 3.57 Pounds respectively). These findings were sensitive to changes in the probability of pericoronitis, periodontal disease and caries. Mandibular third molar retention is less costly to the NHS, more effective for the patient and more cost-effective to both parties than removal. However, should the likelihood of developing pericoronitis, periodontal disease and caries increase substantially then removal becomes the more cost-effective strategy.

Thompson SG, Barber JAHow should costs data in pragmatic trials be analysed? BMJ 320: 1197-1200

Article

Full-text available

May 2000

Health economic evaluations are now commonly included in pragmatic clinical trials that inform policy decisions. Measures other than the arithmetic mean do not provide information about the cost of treating all patients, which is needed as the basis for healthcare policy decisions. Statistical analysis based on transforming cost data or comparing medians using standard non-parametric methods may provide misleading conclusions.

Health economics: an introduction to economic evaluation

Article

Jan 2005

Richard Grieve

The Role of Cost-Effectiveness Analysis in Health and Medicine

Article

Jan 1997

Objective. —To develop consensus-based recommendations guiding the conduct of cost-effectiveness analysis (CEA) to improve the comparability and quality of studies. The recommendations apply to analyses intended to inform the allocation of health care resources across a broad range of conditions and interventions. This article, first in a 3-part series, discusses how this goal affects the conduct and use of analyses. The remaining articles will outline methodological and reporting recommendations, respectively.

Guidelines for authors and peer reviewers of economic submissions to the BMJ

Article

Aug 1996

Post-retention analysis of treatment problems and failures in 264 consecutively treated cases

Article

Feb 1979

Rolf Berg

The results of 264 consecutively treated orthodontic cases were evaluated. According to the defined criteria, optimal treatment objectives were only achieved in 43.2% of the cases. Some of the treatment problems and reasons for failure are identified and discussed. In 16% of cases co-operation problems were the main obstacle to successful treatment. Significant root resorption was observed in 14% of cases. The overall probability for elimination of increased overjet was found to be 71%. Myo-functional problems were an obstacle to treatment in several cases. 1.8% of patients were dissatisfied with the treatment result for aesthetic reasons. It is concluded that close study of treatment problems and failures must be undertaken on an individual basis but 'failure rate' or 'score of success' should be taken into consideration more frequently in clinical orthodontics.

The relative cost effectiveness of water fluoridation across communities: analysis of variations according to underlying caries levels

Article

Apr 1990
COMMUNITY DENT HLTH

Birch Stephen

The effectiveness of water fluoridation as a means of reducing the prevalence of dental caries is well established in the dental literature. The case for water fluoridation however rests on the size of this reduction and the benefits that could be produced by using the same resources in other oral health or dental care programmes. In this paper the cost-effectiveness of water fluoridation is analysed for communities of different sizes and with differing oral health levels. Using the traditional model of economic evaluation, data from recent epidemiological studies, and a number of simplifying assumptions, it is shown that the cost per unit health benefit produced from water fluoridation varies by a factor of four according to the existing level of caries prevalence. Furthermore this is likely to be a conservative estimate of the differential impact given the nature of the assumptions. Marked differences in cost-effectiveness are also found for communities of different sizes suggesting that important economies of scale occur in water fluoridation projects. As a consequence cost effectiveness estimates of water fluoridation projects should be assessed on their own merits to ensure that scarce health care resources are used efficiently, i.e. in a way which maximises the impact these resources have on population health status.

The effect of maxillary retainers on the clarity of speech

Article

Jul 1993
J Clin Orthod

Cost-effectiveness analysis

Article

Oct 1993

R Robinson

When different health care interventions are not expected to produce the same outcomes both the costs and the consequences of the options need to be assessed. This can be done by cost-effectiveness analysis, whereby the costs are compared with outcomes measured in natural units--for example, per life saved, per life year gained, and per pain or symptom free day. Many cost-effective analyses rely on existing published studies for effectiveness data as it is often too costly or time consuming to collect data on cost and effectiveness during a clinical trial. Where there is uncertainty about the costs and effectiveness of procedures sensitivity analysis can be used, which examines the sensitivity of the results to alternative assumptions about key variables. In this article Ray Robinson describes these methods of analysis and discusses possibilities for how the benefits of alternative interventions should be valued.

The role of cost-effectiveness analysis in health and medicine. Panel on Cost-Effectiveness in Health and Medicine

Article

Nov 1996

To develop consensus-based recommendations guiding the conduct of cost-effectiveness analysis (CEA) to improve the comparability and quality of studies. The recommendations apply to analyses intended to inform the allocation of health care resources across a broad range of conditions and interventions. This article, first in a 3-part series, discusses how this goal affects the conduct and use of analyses. The remaining articles will outline methodological and reporting recommendations, respectively. The Panel on Cost-Effectiveness in Health and Medicine, a nonfederal panel with expertise in CEA, clinical medicine, ethics, and health outcomes measurement, was convened by the US Public Health Service (PHS). The panel reviewed the theoretical foundations of CEA, current practices, and alternative procedures for measuring and assigning values to resource use and health outcomes. The panel met 11 times during 2 1/2 years with PHS staff and methodologists from federal agencies. Working groups brought issues and preliminary recommendations to the full panel for discussion. Draft recommendations were circulated to outside experts and the federal agencies prior to finalization. The panel's recommendations define a "reference case" cost-effectiveness analysis, a standard set of methods to serve as a point of comparison across studies. The reference case analysis is conducted from the societal perspective and accounts for benefits, harms, and costs to all parties. Although CEA does not reflect every element of importance in health care decisions, the information it provides is critical to informing decisions about the allocation of health care resources.

Effects of retainers on the articulation of speech

Article

Dec 1996
AM J ORTHOD DENTOFAC

Articulation abilities of 15 patients were evaluated at the end of orthodontic treatment with the initiation of removable upper and lower retainer wear. A test of articulation, based on consonants and vowels (cv), (vcv), (vc), (cvc) nonsense syllables, was used to evaluate the articulatory distortions with no retainers and with maxillary and mandibular retainers worn respectively and together. The test was performed (a) on the first day, (b) 24 hours later, and (c) 1 week later. Statistically significant articulatory distortions with the /t/ and /d/ sounds on the first day with upper retainer only and with both retainers worn together were noted. Also significant distortion of the /k/ sound with both retainers worn was observed. These distortions, due to the wearing of retainers, decreased to an insignificant level or disappeared completely on the seventh day showing the ability of tongue adaptation in a very short period of time.

Specialist orthodontics in the General Dental Service

Article

Apr 1996

This study investigated treatment times and treatment standards produced by 10 specialist orthodontic practitioners working in the General Dental Service (GDS) in England. Twenty cases from each practitioner, consecutively completed with two-arch fixed appliance therapy, were selected and assessed to evaluate treatment times and treatment standards. Observer-generated timings were recorded to provide values for the time taken by these practitioners to perform the various component activities associated with fixed appliance orthodontic therapy. These timings were then pooled to produce an 'average' value for each procedure. Treatment time was assessed retrospectively by applying these average times to the appropriate appointments, as documented on the patient's record card. The treatment duration, number of visits, appliance type and extraction regime were also recorded. Treatment standards were assessed by applying the weighted Peer Assessment Rating Index (PAR Index) to pre- and post-treatment study casts. Relationships between each of these variables were investigated using multiple regression analysis. No relationship was found between treatment time and PAR score change. Predictors of treatment time were the number of visits, and more interestingly, the use of extra-oral forces. However, no useful predictors of the treatment standard were found. On the basis of this sample, it appears that when specialist orthodontic practitioners in the GDS provide two-arch fixed appliance therapy: treatment is completed, on average, in 3-5 hours of chairside time, in 20 visits, spread over 22 months; they provide a high standard of treatment, as assessed by the PAR Index, to a caseload of patients in need to treatment.

Developing outcome measuresin orthodontics that reflect patient and provider values

Article

Jul 1999
Semin Orthod

During the past decade, emphasis in orthodontics has been directed toward the development of outcome measures from both the patient and clinician perspectives. New methodological standards of rigor have been introduced into research design to eliminate bias and test well-defined questions. Sample size calculations and established exclusion and inclusion criteria define sample populations and the ability to statistically accept or reject hypothesis-driven clinical studies. Although advances in our understanding of evidence-based medicine and dentistry from the provider perspective have been productive, the emerging value placed on patient perspective has not been as forthcoming. The emphasis placed on patient-oriented clinical research has resulted in new constructs of surveys and questionnaires in which the items are derived and tested from the patient's point of view. Because orthodontics is a condition without the natural history of a disease process for which no intervention has predictable consequences, new strategies have been developed to estimate need and demand for orthodontic treatment. Studies to measure seekers and nonseekers of orthodontic treatment are reported, as well as sex and cross-cultural issues in the use of established process and outcome measures. The design of clinical studies is discussed in the context of future directions for clinical research, and the usefulness of the information generated will directly relate to providing patients with the necessary information to make decisions and hence knowledgeably give informed consent for treatment interventions.

Understanding orthodontic treatment satisfaction from the patients' perspective: a qualitative approach

Article

Jun 1999

To apply qualitative research methods to develop hypotheses about orthodontic treatment process and outcome, as well as treatment satisfaction. Four focused interviews with 4-8 adolescents in retention. UNC orthodontic clinic; 22 patients in retention. Patients expressed dissatisfaction with some aspects of the treatment process, but were generally satisfied with the treatment outcome. Patients were aware of differences between clinic versus private treatment. From these discussions, we infer that there may be important differences between patients' and orthodontists' perceptions of the treatment process. Qualitative methods are useful tools for exploring orthodontic treatment from the patients' perspective and can be used to suggest important future areas of research.

How to … Write and analyse a questionnaire

Article

Oct 2003

A Williams

Questionnaires are used in a wide range of settings to gather information about the opinions and behaviour of individuals. As with any other branch of science, the validity and reliability of the measurement tool, i.e. the questionnaire, needs to be rigorously tested to ensure that the data collected is meaningful. The design and method of administration of a questionnaire will also influence the response rate that is achieved and the quality of data that is collected. This paper discusses the issues that should be considered when designing and undertaking a questionnaire study.

Cost-Effectiveness of Infant Orthopedic Treatment Regarding Speech in Patients With Complete Unilateral Cleft Lip and Palate: A Randomized Three-Center Trial in the Netherlands (Dutchcleft)

Article

Feb 2004

To investigate the cost-effectiveness of infant orthopedic treatment (IO), compared with no such treatment in children with complete unilateral cleft lip and palate (UCLP) focusing on the effects on speech development at age 2.5 years. In a three-center prospective, randomized clinical trial (Dutchcleft), two groups of children with complete UCLP were followed longitudinally: one group was treated with IO based on a modified Zurich approach in the first year of life (IO group) and the other group did not receive this treatment (non-IO group). The participants had complete UCLP without soft tissue bands or other malformations. They were born at term and their parents were native Dutch speakers. The effect of IO on speech development at age 2.5 years was measured blindly by five expert listeners judging the "total impression of speech quality" on a 10-point equal-appearing interval scale. Costs were measured from a societal viewpoint in Euro. The IO group (n = 10) obtained a statistically significant higher rating, compared with the non-IO group (n = 10). The effect size was large, indicating that the improvement may be considered a clinically important change. The cost for treatment by the orthodontist was higher in the IO group. For both groups, the mean cost was related to the mean rating for "total impression of speech quality." The resulting cost-effectiveness for IO, compared to non-IO was 1041 for 1.34 point speech quality improvement. The financial investment that is necessary to obtain this improvement seems limited. Thus, from the perspective of speech development, the cost-effectiveness of IO over non-IO seems acceptable at this point in time.

Evaluating the Cost-Effectiveness of Orthodontic Provision

Article

May 2004

The assessment of orthodontic provision is important to determine if treatment was necessary and undertaken appropriately. The ICON objectively quantifies orthodontic treatment need, complexity and outcome and is a valuable occlusal index in the assessment effectiveness of orthodontic care. It is possible to develop cost-effectiveness models by analysing the costs and effectiveness of orthodontic treatment. Several methods are illustrated to compare the orthodontic provision of specialist orthodontists.

Scientific section: The development of a patient-centered measure of the process and outcome of combined orthodontic and orthognathic treatment

Article

Oct 2004

The aim of this study was to develop a patient-based measure of the process and outcome of combined orthodontic and orthognathic care in the National Health Service in the UK. Identification of relevant dimensions through qualitative methods, design of form, determination of psychometric properties of the scale, specific readability, reliability and validity. NHS hospitals in the South West Region. The sample comprised patients who had received combined orthodontic and orthognathic treatment between 01 January 1998 and 31 December 2000. Twenty-six participants (a 25% response rate) took part in four focus group meetings. Thirty subjects (65% response rate) took part in a pilot study to test the properties of the questionnaire. Six broad themes emerged from the focus groups. These formed the basis of the sections in the questionnaire. The questionnaire developed had a Flesch reading ease score of 72.9 or US grade level 4 equivalent to aged 9-10 years. Test-retest reliability gave kappa values for most questions that exceeded 0.4. Criterion validity of the measure was established by comparing responses to the questionnaire over two periods with a telephone interview on a sample of 30 patients. Criterion related validity was poor for nine of the 16 items. By contrast the construct validity of the questionnaire was satisfactory. A patient-based measure of the process and outcome of combined orthodontic and orthognathic treatment has been developed. This has sufficient validity and reliability for use in inter-center audit projects.

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

Article

Jan 2008

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.

Evaluating the feasibility of developing national outcomes databases to assist patients with making treatment decisions

Mar 2003

C Damberg

Damberg C L 2003 Evaluating the feasibility of developing national outcomes databases to assist patients with making treatment decisions. ( http://www.rand.org/publications/bib/sra2003.pdf ). (last accessed 1 March 2003)

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

Abstract

No full-text available

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