Poly-Ether-Ether-Ketone versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 2: periodontal health and microbial biofilm assessment.

BACKGROUND: Retainers have the potential to detrimentally impact periodontal health and contribute to tooth decay. OBJECTIVES: To investigate periodontal health and bacterial biofilm related to Poly-Ether-Ether-Ketone (PEEK) fixed retainers as compared to Dead-soft coaxial fixed retainer (DSC). TRIAL DESIGN: A two-arm parallel groups single-centre randomized clinical trial. METHODS: The trial included patients whose orthodontic treatment was completed and required retainers. Participants were randomly assigned into two retainer groups: PEEK retainers, prepared by computer-aided design and manufacturing into 0.8 mm wire form, and DSC retainers. The objectives included assessing periodontal health through plaque accumulation index (PI), bleeding on probing (BOP), periodontal pocket depth (PPD), gingival index (GI), calculus index (CI), and alveolar bone height (ABH) assessment. Biofilm assessment involved bacteriological screening of aerobic, facultative anaerobic, mutans streptococci, and lactobacilli. The periodontal indices and microbiological screening as well as were assessed at the debonding stage (T0), 1-month (T1), 3-month (T3), and 6-month (T6) after the commencement of the trial, except for the ABH, which was recorded using periapical radiograph at T0 and T6. BLINDING: Single blinding of participants in addition to the bacteriological specialist. RESULTS: Initially, the trial enrolled 46 participants, aged between 12 and 28 years, and were randomly assigned to two groups, with 23 participants in each group. Subsequently, one participant withdrew from the trial, resulting in a total of 45 participants whose data were analysed. Assessment of the periodontal indices, excluding the CI (P = .480), revealed statistically but not clinically significant differences between groups after 6-month of retention (P = .016 of PI, P = .020 of BOP, P = .05 of PPD, and P = .01 of GI). There was slight plaque accumulation, normal PPD (approximately 1 mm), healthy to mild gingivitis with a GI of less than 1 and BOP was around 10%. Concerning the ABH, there was a noticeable reduction in its score after 6 months, particularly in the PEEK group, although the difference was not statistically significant (P = .102). Furthermore, the bacteriological viable count did not show any significant difference between the groups during the recall visits. HARMS: There have been no reported negative consequences. LIMITATIONS: Blinding the assessor of periodontal indices was not feasible due to the nature of the intervention. The trial follow-up duration was limited. CONCLUSIONS: Both the PEEK and DSC retainers have comparable impacts on periodontal health and bacterial accumulation and composition during the retention period. TRIAL REGISTRATION: NCT05557136.

Poly-ether-ether-ketone (PEEK) versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 1. Stability, retainer failure, and participant satisfaction.

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).

FIBER REINFORCED COMPOSITE RETAINERS MAY BE AS EFFECTIVE AS MULTISTRANDED STAINLESS-STEEL WIRES IN FAILURE RATES AND MINIMAL ADVERSE EFFECT, BUT SUPERIOR IN TERMS OF RELAPSE AND PATIENT SATISFACTION.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Liu S, Silikas N, Ei-Angbawi A. Analysis of the effectiveness of the fiber-reinforced composite lingual retainer: A systematic review and meta-analysis. Am J Orthod Dentofacial Orthop. 2022 Aug 26:S0889-5406(22)00,432-2. doi: 10.1016/j.ajodo.2022.07.003. Epub ahead of print. PMID: 36,031,511. SOURCE OF FUNDING: Not reported. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Comparative assessment of relapse and failure between CAD/CAM stainless steel and standard stainless steel fixed retainers in orthodontic retention patients.

OBJECTIVES: To compare relapse and failure rates of computer-aided design/computer-aided manufacturing (CAD/CAM) and standard fixed retainers. MATERIALS AND METHODS: This single-center, single-blinded, prospective randomized clinical trial included 46 patients who completed active orthodontic treatment and complied with retention visits. The patients were randomly assigned to three groups: CAD/CAM group with multistranded stainless steel wires (CAD/CAM, n = 16), Lab group with the same multistranded wires (lab, n = 16), and control group with stainless steel Ortho-FlexTech wires (traditional, n = 14). Intraoral scans were obtained at placement of fixed retainers (T1), 3-month visit (T2), and 6-month visit (T3) and measured for intercanine width and Little's Irregularity Index. Failures were recorded. RESULTS: The CAD/CAM group experienced less intercanine width decrease than the traditional group at 3 months (mean difference, 0.83 ± 0.16 mm; 95% confidence interval [CI], 0.44-1.22; P < .001) and 6 months (mean difference, 1.23 ± 0.40 mm; 95% CI, 0.19-2.27; P < .05). The CAD/CAM group experienced less increase in Little's Irregularity Index compared with the lab group within 3 months (mean difference, 0.81 ± 0.27 mm; 95% CI, 0.12-1.49; P < .05). Failures from greatest to least were experienced by the lab group (43.8%), the CAD/CAM group (25%), and the traditional group (14.3%). CONCLUSIONS: Within 6 months of bonding fixed retainers, CAD/CAM fixed retainers showed less relapse than lab-based and traditional chairside retainers and less failures than lab-based retainers.

Three-dimensional imaging and molecular analysis of the effects of photobiomodulation and mechanical vibration on orthodontic retention treatment in rats : Effects of photobiomodulation and mechanical vibration on orthodontic retention treatment.

PURPOSE: We aimed to evaluate and compare effects of photobiomodulation (PBM) and low-magnitude high-frequency mechanical vibration (HFMV) on orthodontic retention. METHODS: Sixty-four female Wistar albino rats were divided into 9 groups (2 negative and positive controls each, 3 PBM and 2 HFMV groups) and studied for 25 days. In the experimental groups, closed nickel-titanium closed coil springs with a 50 cN force were placed for 10 days between the maxillary incisor and molar. PBM and HFMV were applied daily over long- (15 days) and short-term (7 days) retention periods. The PBM groups received PBM with a single wavelength (650 nm) or higher wavelengths (532, 650, 940 nm) for 9 min per day. HFMV groups received HFMV of 10, 20, and 30 Hz for 10 min per day. Right and left maxilla were assessed using micro-computed tomography imaging and real-time polymerase chain reaction. The amount of tooth movement during the retention period, expression levels of cyclooxygenase­2 (COX-2), osteoprotegerin (OPG), and receptor activator of nuclear factor-kappa B ligand (RANKL) mRNA gene expression levels, OPG/RANKL ratios, alveolar bone trabecular thickness (Tb.Th), trabecular number (Tb.N), and structure model index were analyzed. Kruskal-Wallis and Mann-Whitney U tests were used for multiple comparisons of the nonparametric distributed data and binary comparisons, respectively. RESULTS: When using the long-term retention protocol, PBM and HFMV treatment increased Tb.N (p < 0.05) and decreased COX­2 mRNA gene expression levels (p < 0.05) and Tb.Th (p < 0.05) compared to controls. For short-term retention, PBM and HFMV decreased the amount of relapse tooth movement compared to controls. In addition, Tb.Th (p < 0.05) and the mRNA gene expression levels of COX­2 and RANKL (p < 0.05) were decreased. CONCLUSION: PBM and HFMV might be able to support retention after orthodontic tooth movement by reducing bone resorption and increasing bone quality.

Anterior openbite malocclusion in adults.

OBJECTIVES: To investigate stability and satisfaction in adult anterior open bite (AOB) patients at least 9 months post-treatment, as well as patient and practitioner factors that may be associated with stability and satisfaction. MATERIALS AND METHODS: Practitioners and their adult AOB patients were recruited through the National Dental Practice-Based Research Network. Data on patient and practitioner characteristics, treatment recommendations and factors were previously collected. Treatment stability was determined by assessing post-treatment intraoral photographs. Patient satisfaction was determined from post-treatment questionnaires. Treatment was categorized into aligners, fixed appliances, temporary anchorage devices, and orthognathic surgery. Extractions were also investigated. Retention type was categorized into vacuum-formed, Hawley-style, or bonded retainers, and regimens were classified as full-time or part-time wear. RESULTS: Retention data collected from 112 patients had a mean post-treatment time of 1.21 years. There were no statistically significant differences in stability between treatment groups. Depending on whether a qualitative index or a millimetric measure was employed, stability ranged from 65% to 89%. Extractions and less initial lower incisor proclination were associated with higher stability in patients treated with fixed appliances only. High satisfaction was reported by patients at retention. There were no clear differences in stability or satisfaction among retention types or regimens. CONCLUSIONS: The stability of adult AOB orthodontic treatment was high, regardless of treatment or retainer modality. Satisfaction in adult AOB patients was high, regardless of retention type or regimen.

Caracterización morfológica de caninos en premolares, un caso de anodoncia parcial de caninos maxilares / Morphological characterization of canine teeth done in first bicuspid, a maxillary canine partial anodontia case report

En este informe de caso clínico se muestra el tratamiento exitoso de un paciente con anodoncia parcial de órganos dentales 13 y 23 debido a que fueron extraídos por presentar impactación y mal pronóstico de tracción. En este artículo se presenta un paciente masculino de 29 años clase I esquelética con un perfil convexo, maloclusión de clase III, overjet disminuido, ausencia de guías funcionales, discrepancia oseodentaria positiva en arcada superior y negativa en arcada inferior. El tratamiento se realizó con extracciones de los órganos dentales 34 y 44 para nivelar las discrepancias óseo dentarias interarcadas, se llevó a cabo mediante un cierre de espacios recíproco por medio de cadenas elásticas para ambas arcadas, con lo que se logró crear un overjet y overbite adecuados. La creación de las guías caninas funcionales se consiguió mediante el cambio de morfología de los órganos dentales 14 y 24, los cuales fueron llevados a la posición de los caninos ausentes. El tiempo total de tratamiento para este paciente fue de 24 meses. Se realizaron ameloplastias positivas, la aplicación de agregados de resina para mejorar la funcionalidad y proveer salud articular. Se sugiere que ante casos de anodoncia de caninos en la arcada superior, un tratamiento favorable se puede llevar a cabo mediante el cierre de espacios, la caracterización morfológica de los caninos ausentes mediante ameloplastias positivas en premolares (AU)

This case report shows the successful treatment of a patient with partial anodontia of dental organs 13 and 23 because they have been extracted due to present impactation and poor traction prognosis. This article presents a 29-year-old male class I skeletal patient with convex profile, class III malocclusion, overjet reduction, absence of functional guidance, positive bone-teeth discrepancy in the upper arch and negative in the lower arch. The treatment was carried out with the extractions of the dental organs 34 and 44 for correcting oral dental discrepancies between upper and lower arches; it was done using reciprocal closing of spaces by using elastic chains for both arches in order to achieve a suitable overjet and overbite. The creation of the canine guides was achieved by changing the morphology of the dental organs 14 and 24, which were taken to the position of the absent canines. The total treatment timing for this patient was 24 months. Positive ameloplasties were performed by application of resin aggregates to improve functionality and provide joint health. A favorable treatment for these kinds of cases of canine anodontics in the upper arch is carried out by closing spaces and the morphological characterization of the absent canines by positive in-premolar ameloplasties (AU)

Retenedores de Ortodoncia y su Efecto sobre la Salud Periodontal: revisión de la Literatura / Orthodontic Retainers and Their Effect On Periodontal Health: literature Review

Existe una prescripción generalizada de retenedores fijos y removibles, con indicación indefinida, luego del tratamiento ortodóncico. El objetivo de este estudio fue dilucidar el impacto de los retenedores de ortodoncia sobre la salud periodontal de los dientes. Se realizó una búsqueda y análisis de artículos científicos de las bases de datos PubMed, ScienceDi rect, SciELO, LILACS y Google Scholar. Los artículos seleccionados fueron publicados entre los años 2015 y 2020 en base a criterios de inclusión y exclusión. Nuestra revisión sugiere que la indicación de un retenedor fijo o removible presenta mayores benefici os que riesgos y no significa, cuando son consideradas las características individuales de cada paciente, el detrimento de la salud periodontal. Sin embargo, son necesarios nuevos estudios prospectivos, con un tiempo de seguimiento suficiente y la presencia de un grupo control, para poder extrapolar resultados y los potenciales daños asociados con los retenedores de ortodoncia.

Due to the high prescription after orthodontic treatment of fixed and removable retainers with an indication of indefinite use, the aim of this study was to find the impact of orthodontic retainers on the periodontal health of the teeth. we proceed to search and analyze scientific articles from databases PubMed, ScienceDirect, SciELO, LILACS and Google Scholar, selected articles were published between 2015 and 2020 based on inclusion and exclusion criteria. Our review suggests that the indication of a fixed or removable retainer presents greater benefits than risks and does not mean, when considering the individual characteristics of each patient, the detriment of periodontal health. However, new prospective studies with a longer follow- up time and the presence of a control group are necessary to be able to extrapolate results and elucidate the possible damages associated with orthodontic retainers.

Periodontal status in long-term orthodontic retention patients up to 10 years after treatment - a cross-sectional study.

OBJECTIVE: To assess periodontal status in long-term orthodontic retention patients and investigate possible risk indicators. MATERIALS AND METHODS: Plaque index (PI), gingival index (GI), probing pocket depth (PPD), gingival recessions (GR) and calculus were recorded in 211 patients with or without fixed retainers. RESULTS: Periodontal parameters were within the limits of clinically healthy periodontium. The use of fixed retainers was associated with higher PI in the maxilla (ß = 1.10 [0.37]; p <.05). Older age was associated with higher PI in the mandible (ß = 0.27 [0.11]; p <.05). Smoking was associated with gingival bleeding on both palatal (ß = 0.63 [0.16]; p < .01) and labial sides in the maxilla (ß = 0.46 [0.20]; p <.05). Smoking was also associated with increased prevalence of GR in the mandible (ß = 0.24 [0.07]; p <.01), while use of snuff had similar effect on the labial side in the maxilla (ß = 0.35 [0.08]; p <.01). Higher age (ß = 0.05 [0.02]; p <.05) and the presence of a retainer (ß = 0.23 [0.07]; p < .05) were associated with calculus accumulation on the lingual side in the mandible. CONCLUSION: The present observational study suggest that long-term fixed retainers alone have no detrimental effect on the periodontium. Additional factors may increase the risk of plaque deposits and increased probing pocket depths. Further prosepective studies are needed to confirm the present outcome.

[The new retainers in Dento-Facial Orthopedics]. / Les nouvelles contentions en orthopédie dento-faciale.

Digital technologies are gradually integrating our orthodontic practices and retainers, often less considered compared to active devices, are also benefiting. The author will give in this article a brief presentation of the various current possibilities offered by the use of digital tools for carrying out and monitoring fixed or removable retention methods. The digital workflow is perfectly suited to the production of modern and durable retainers, whether for fixed or removable devices, as well as their long-term monitoring. The objective is not to decide on the superiority of one system over another, but to expose all the possibilities for adapting the digital tool to the orthodontist's method of retention. The benefit of using digital technology is saving time and improving performance, minimizing unnecessary manipulation and improving device precision. Digital technology provides all the elements necessary to achieve new generation retainers both more simply, and for them to be more precise and more durable. These technologies are in constant progress and we can still consider improvements in the near future as software and hardware developments progress.

Comparing the effects of CAD/CAM nickel-titanium lingual retainers on teeth stability and periodontal health with conventional fixed and removable retainers: A randomized clinical trial.

OBJECTIVE: The objectives of this study were to evaluate the effect of a CAD/CAM nickel-titanium retainer on the stability of mandibular anterior teeth and periodontal health and to compare it with other retainers. SETTING/SAMPLE POPULATION: Sixty participants from both genders who had irregularities prior to orthodontic therapy and who had been treated with full-fixed appliance mechanotherapy were included in the study and randomly allocated into four groups: CAD/CAM NiTi, multi-stranded stainless steel, single-stranded nickel-free titanium and vacuum-formed removable retainer groups. The mean age of the participants at the end of the treatment was approximately 20 years. MATERIALS AND METHODS: Digital impressions were taken for all participants at three different times: immediately (T0 ), three months (T1 ) and six months (T2 ) after treatment. Irregularity index, inter-canine and inter-molar width, and arch length were recorded using software. Additionally, a full periodontal assessment was carried out at T2 . RESULTS: During the follow-ups, all groups showed some relapse in the lower anterior teeth. No statistical significance was found intergroup in terms of all measured values. Within the multi-stranded group, inter-canine width had decreased by 0.10 mm with a statistical significance (P = .048). An additional statistical significance with P = .045 was found within the single-stranded group regarding the increased arch length. The periodontal assessment results of the mandibular anterior teeth between groups did not show clinically significant differences. CONCLUSION: No statistical significance was found between the CAD/CAM retainer and other retainers regarding the clinical failure rate. Less plaque accumulation and gingival inflammation were observed in the CAD/CAM NiTi retainer group.

In vitro comparison of the torsional load transfer of various commercially available stainless-steel wires used for fixed retainers in orthodontics.

OBJECTIVE: To assess the torsional load transfer of various commercially available stainless-steel wires used for fixed retainers. DESIGN: An in vitro study using a robotic device. SETTING: Department of Pediatric Oral Health and Orthodontics, University of Basel. METHODS: A 10° proclination of a maxillary lateral incisor of a 2-2 retainer was simulated with a robotic device. Eight stainless-steel wires with different shapes (round or rectangular), types (plain, braided, coaxial or chain) and dimensions were selected to measure the torsional load transfer at the adjacent central incisor. The influence of annealing was also tested. RESULTS: The 0.016 × 0.016 and Bond-A-Braid™ wires (0.02645 × 0.01055-inch, 8-stranded, braided) showed the largest relative torsional load transfer (3.7% and 3.3%, respectively). The two multistranded wires - Triple Flex™ and Respond® - showed the smallest values of 1.0% and 0.7%, respectively. The spiral direction of these two multistranded wires affected the load transfer, the twisting showing larger torsional load transfer than the untwisting one. CONCLUSION: The effective torsional load transfer depends on the dimension, shape and type of a wire. Plain and braided retainers were more predictable in torsional load transfer than multistranded retainers, which may have stored more energy in the area between the composite bonding sites. This may explain the unexpected complications reported in multistranded retainers.

Difference in Orthodontic Patients' Perceptions of Essix and Hawley Retainers

Abstract Objective: To determine differences in how orthodontic patients perceive the aesthetics relating to the use of Essix and Hawley retainers. Material and Methods: Photographs of a female patient using an Essix retainer and a Hawley retainer, respectively, were assessed by 70 orthodontic patients aged between 21 and 55 years. All participants were provided with the same images of the two retainer types being worn and were asked to grade the aesthetics of each retainer using a visual analog scale. The significance of differences in orthodontic patient perceptions of aesthetics in the use of Essix and Hawley Retainers in the young adult and adult age groups were tested using the Mann-Whitney test with assumed significance p<0.01. Results: There were differences in participants' perceptions between the two retainers that were statistically significant, with responses varying between young adults aged 21 to 35 years and adults aged 36 to 55 years. According to the VAS, the two retainers' average scores in the total population are 82 for Essix Retainer and 60 for Hawley Retainer in both groups. Conclusion: The Essix retainer as a retention appliance is considered more aesthetically pleasing than the Hawley retainer among both young and middle-aged adults.

Retenciones múltiples. Reporte de un caso / Multiple retention. Case report

RESUMEN La retención dentaria es común encontrarla en la clínica de ortodoncia, los caninos maxilares son los de mayor solicitud de tratamiento por su importancia estética. Sin embargo, no es frecuente la retención de dientes temporales. Su etiología no está bien definida pero se considera de carácter multifactorial. Se presentó una paciente del sexo femenino de 12 años y medio de edad, con ausencia de 15 y 13, presencia de 53 y mesogresión del 16. Al examen radiográfico se observó retención de 55, 15 y 13, este último en transposición incompleta con el 12. Después de un profundo análisis se decidió exéresis del 55 y alineación al arco dentario de 15 y 13, mediante colocación de un dispositivo, con el empleo del sistema de cementado directo en el acto quirúrgico. Se estableció una oclusión funcional y estética aceptable, con particular cuidado de la integridad de los dientes vecinos y sus tejidos blandos. Las retenciones constituyen maloclusiones dentarias complejas y de difícil pronóstico y tratamiento, más aún cuando son múltiples. Se requiere de estudio y tratamiento multidisciplinario (AU).

ABSTRACT It is common to find teeth retention in Orthodontics clinic; maxillary canines, due to their esthetical importance, are the ones the patients ask to be treated more frequently. Nevertheless, temporary teeth retention is not frequent. Its etiology is not clear, but it is considered multifactorial. The authors present the case of a female patient, aged 12 years and a half, without 15 and 13 teeth, presence of 53 and mesogression of 16. At the radiographic examination, the retention of 55, 15 and 13 was found, and also the incomplete transposition of 13 and 12. After deeply analyzing the case, the orthodontists decided the removal of 55 and aligning 15 and 13 to dental arch, placing a device with the system of direct cementing at the moment of the surgery. It was established a functional occlusion and an acceptable esthetics, particularly caring for the neighboring teeth and their soft tissues. Retentions are complex dental malocclusions, of difficult prognosis and treatment, mainly when they are multiple. They require study and multidisciplinary treatment (AU).

Tratamiento de Ortodoncia en un paciente con síndrome de Down / The Orthodontics treatment in a patient with Down syndrome

RESUMEN El tratamiento de Ortodoncia en pacientes con síndrome de Down, ha sido un tema debatido durante muchos años por los especialistas debido a las deficiencias físicas, mentales y a la dificultad de estos en la cooperación con el tratamiento. El objetivo de este trabajo es mostrar resultados adecuados de tratamiento ortodóncico en una paciente femenina de 12 años de edad con síndrome de Down. La niña acudió a consulta acompañada de su mamá y de su abuela solicitando tratamiento por presentar los dientes virados. En el examen clínico se observó rotación marcada de 11 y 21 mayor de 900 que afecta su estética facial. Se explicó a la familia lo difícil que podía resultar el tratamiento a esta adolescente con necesidades especiales, a la que habría que aplicar una fuerza ortodóncica que genera marcada molestia y pudiera presentarse una escasa tolerancia al dolor. La familia aseguró su cooperación. Se decidió emprender la terapia para lo cual se diseñó un plan de tratamiento en dos etapas. En una primera etapa se empleó aparatología ortodóncica removible y en una segunda etapa aparatología fija. Al concluir el tratamiento se logró resolver de manera satisfactoria el motivo de consulta con buena cooperación por parte de la paciente y su familia. El éxito del tratamiento se debió a la satisfactoria cooperación de la paciente y al establecimiento de una relación favorable ortodoncista-paciente-familia (AU).

ABSTRACT The Orthodontics treatment in patients with Down syndrome has being a theme debated by specialist during many years, due to the physical and mental deficiencies of this kind of patients and their difficulty in cooperating with the treatment. The aim of this article is showing the adequate results of the orthodontic treatment in a female patient aged 12 years with Down syndrome. The girl assisted to consultation with her mother and grandmother asking treatment for having crooked teeth. At the physical examination it was observed a remarked rotation of 11 and 21 of more than 900, affecting her facial esthetics. Doctors explained to relatives that the treatment could result very difficult to this teenager with special requirements due to the application of an orthodontic force generating great discomfort in this girl, possibly having a scarce tolerance to pain. The relatives agreed to cooperate. They decided to start the therapy, and a two-stage plan was designed. In the first stage, removable orthodontic braces were used, and fixed ones were used in the second stage. At the end of the treatment the cause of the consultation was successfully solved with a good cooperation of the patient and her relatives. The success of the treatment was achieved due to the satisfactory cooperation of the patient and the establishment of a favorable relationship orthodontist-patient-family (AU).

Removable partial dentures: eliminating retainers in the anterior zone / Prótesis parcial removible: eliminación de retenedores en la zona anterior

Abstract Introduction: one of the main factors for discomfort in users of removable partial prosthesis is the presence of visible retainers in the anterior zone. In Kennedy Class III arches, that is, exclusively dental loading pathways (in which the functional forces reach their final receptor: the alveolar bone), anterior zone retainers may be eliminated by selecting an appropriate prosthetic insertion and removal axis, and mainly by carving guiding planes that should provide retention by mechanical rubbing. This in vitro experimental study aimed to prove the hypothesis that it is possible to obtain functional retention in a dental-loading pathway removable partial prosthesis without using retainers in the anterior zone. Methods: 7 maxillary models with different types of toothless process were used. As a common characteristic, they all were classified as Kennedy Class III with partial denture arches. A Cr-Co metallic base was built for each model according to their clinical situation. Their design allowed them to be exposed to traction in a universal traction machine (Tinius Olsen H5K-S). Results: the proposed hypothesis was confirmed as expected. The traction force needed to displace the metallic bases with retainers in the anterior zone was 16.93 Newton in average. On the other hand, the metallic bases without retainers in the anterior zone showed an average of 12.84 N. The average values obtained for both groups are higher than those reported in the literature (4.903 N). Conclusions: in Class III removable partial dentures it is possible to use metallic bases with no retainers in the anterior zone.

Resumen Introducción: un factor que incomoda a los usuarios de prótesis parciales removibles es la presencia de retenedores visibles en la zona anterior. En clases III de Kennedy, es decir, vías de carga exclusivamente dentarias, sería posible eliminar los retenedores del sector anterior mediante un adecuado tallado de planos guías que brinde retención por roce mecánico y la elección de un eje de inserción y remoción protésico. Este trabajo es un diseño experimental in vitro que tiene por finalidad validar la hipótesis propuesta por nuestro equipo de investigación, que es posible obtener retención funcional en una prótesis parcial removible de vía de carga dentaria sin utilizar retenedores en el sector anterior. Métodos: se utilizaron 7 modelos maxilares en yeso tipo IV, con distinto tipo de desdentamiento, cuya característica común era que correspondían a clases III de Kennedy de arcos parcialmente desdentados. A cada modelo se le confeccionó una base metálica de Cr-Co, de acuerdo con sus características clínicas individuales, las cuales presentaron un diseño que permitió utilizarlas en una máquina de tracción universal para someterlas a fuerzas de tracción. Resultados: la fuerza de tracción necesaria para desalojar las bases metálicas que contaban con retenedores en el sector anterior fue del orden de 16,93 N en promedio. En cambio, las bases metálicas sin retenedores en el sector anterior presentaron un valor promedio para su desalojo de 12,84 N. Conclusiones: los valores promedio obtenidos para ambos grupos son superiores a los que se señala en la literatura (4,903 N) como válidos para una retención adecuadamente funcional para una prótesis parcial removible.

Periodontal parameters of two types of 3 x 3 orthodontic retainer: a longitudinal study

ABSTRACT Introduction: bonded fixed retainers are often used to stabilize the results obtained with the orthodontic treatment. It is important that they do not prejudice dental health, as they will be used for a long period. Objective: The purpose of the present study was to compare periodontal indexes between two types of bonded fixed retainers, conventional 3 x 3 plain retainer (0.8-mm orthodontic wire, bonded to the canines only) and a manufactured braided retainer (0.2 x 0.7-mm stainless steel wire, bonded to all anterior teeth) after use. Methods: a test group of 15 volunteers (aged from 18 to 25 years) used both the conventional retainer and braided retainer for six months. A randomized longitudinal study design, with a two week washout interval, was applied. The dental plaque index, gingival index and dental calculus index were evaluated. Furthermore, the calculus accumulated along the retainer wire was measured and all patients answered a questionnaire about the use, acceptance and comfort of both types of retainers. Results: the scores for plaque and gingival indexes were higher for the braided retainer (p< 0.05) on the lingual and proximal surfaces. The same occurred with the calculus index on the lingual surfaces (p< 0.05). The calculus index along wire was higher for the braided retainer (p< 0.05). All patients preferred the conventional retainer, and said that it was also more comfortable to use. Conclusion: it was concluded that the conventional retainer showed better periodontal indexes than the braided type.

RESUMO Introdução: as contenções ortodônticas fixas são amplamente utilizadas após o tratamento ortodôntico, sendo fundamental que esses dispositivos não se tornem prejudiciais à saúde dentária, já que serão usados por um longo período. Objetivo: o presente estudo teve como objetivo a avaliação periodontal da região da arcada inferior, comparando as condições de acúmulo de placa e cálculo ao longo do fio e na margem gengival, em decorrência do uso da contenção convencional (fio 0,8 mm de aço inoxidável colado apenas nos caninos) ou de uma contenção pré-fabricada com fio trançado (0,2 x 0,7 mm colado em todos os dentes anteroinferiores) após exposição ao meio bucal. Métodos: participaram do estudo 15 voluntários adultos jovens (idades entre 18 e 25 anos) que utilizaram dois tipos de contenções, por seis meses cada. Foi utilizado um modelo de estudo longitudinal, randomizado, com washout de 15 dias. Os parâmetros periodontais utilizados foram: índice gengival, índice de placa e índice de cálculo. O cálculo acumulado ao longo da contenção foi avaliado e todos os pacientes responderam a um questionário sobre o uso, aceitação e conforto de ambos os tipos de contenção. Resultados: observou-se que o índice de placa foi maior para a contenção com fio trançado (p<0,05), assim como o índice gengival (p<0,05). O mesmo ocorreu para o índice de cálculo nas faces proximais e lingual (p<0,05). O índice de cálculo ao longo do fio também foi significativamente maior para a contenção com fio trançado (p<0,05). Em relação ao questionário aplicado, 60% dos voluntários consideraram que a contenção com fio trançado foi mais desconfortável, e todos eles preferiram a contenção convencional. Conclusão: concluiu-se que a contenção convencional apresentou melhores resultados periodontais, quando comparada à contenção pré-fabricada com fio trançado.

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

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