Effect of printing orientation on mechanical properties of 3D-printed orthodontic aligners.

PURPOSE: The purpose of this study was to assess differences in the fundamental mechanical properties of resin-made three-dimensional (3D) printed orthodontic aligners according to the printing orientation. METHODS: Twenty resin 3D-printed dumbbell-shaped specimens and 20 orthodontic aligners were fabricated and postcured in nitrogen. Half of the specimens and aligners were built in horizontal (H), the other half in vertical (V) directions. The dumbbell-shaped specimens were loaded in a tensile testing machine, while parts of the aligners were embedded in acrylic resin, ground, polished, and then underwent instrumented indentation testing (IIT). Mechanical properties that were assessed included the yield strength (YS), breaking strength (BS), plastic strain (ε), Martens hardness (HM), indentation modulus (EIT), elastic index (ηIT), and indentation relaxation (RIT). Data were analyzed statistically with independent t­tests or Mann-Whitney tests at α = 5%. RESULTS: No significant differences were found between specimens or aligners printed either in a horizontal or a vertical direction (P > 0.05 in all instances). Overall, the 3D-printed aligners showed acceptable mechanical propertied in terms of YS (mean 19.2 MPa; standard deviation [SD] 1.7 MPa), BS (mean 19.6 MPa; SD 1.2 MPa), ε (mean 77%; SD 11%), HM (median 89.0 N/mm2; interquartile range [IQR] 84.5-90.0 NN/m2), EIT (median 2670.5 MPa; IQR 2645.0-2726.0 MPa), ηIT (median 27.5%; IQR 25.9-28.1%), and RIT (mean 65.1%; SD 3.5%). CONCLUSION: Printing direction seemed to have no effect on the mechanical properties of 3D-printed resin aligners, which are promising for orthodontic use.

Is wear time of Hawley retainers measured with microsensors related to mandibular arch stability?

PURPOSE: The aim of this study was to show a possible correlation between the mean wear time of Hawley retainers and long-term mandibular arch stability as assessed via wear time analysis with microsensors. METHODS: This longitudinal retrospective study comprised 47 subjects (mean age 16.30 ± 1.06 years) having been treated with a nonextraction protocol and presenting moderate crowding at pretreatment. For retention, all patients were instructed to use a mandibular Hawley retainer for 12 months, and wear time was documented every 3 months during a posttreatment period of 6 months using TheraMon software. These individuals were divided into two groups. Those who adhered to a wear time equal to or more than 12 h/day (group 1A; N = 17) and those who complied for less than 12 h/day (group 2A; N = 30) were compared with respect to changes of the mandibular arch during the first 6 months of retention. Furthermore, a subgroup of 28 patients who completed a 12-month follow-up period were again divided into two groups: the individuals in group 1B (N = 12) adhered to a wear time equal to or more than 8 h/day, while those in group 2B (N = 16) complied for less than 8 h/day. Little's Irregularity Index, intercanine and intermolar widths, arch length, overjet, and overbite were measured on mandibular models taken at pretreatment (T0) and posttreatment (T1), as well as 6 months (T2) and 12 months (T3) after debonding. Pearson correlation test, independent samples t­test, and Mann-Whitney U test were used for statistical evaluation. RESULTS: From T1 to T2, group 1A and group 2A showed a significant relapse in intermolar width with a difference in the median value of 0.38 mm (p = 0.019). At the complete 12-month follow-up, the increase in Little's irregularity score was significantly greater in group 2B (2.54 ± 1.29 mm) than in group 1B (1.32 ± 1.03 mm; p = 0.012). The established wear time measurements showed significant negative correlations with the Little's irregularity score and overjet changes between T1 and T3 (p < 0.05). CONCLUSIONS: The results emphasized that the use of a retainer should not fall below a level of at least 8 h/day.

Assessment of the periodontal health status and gingival recession during orthodontic treatment with clear aligners and fixed appliances: A systematic review and meta-analysis

Background: The aim was to assess periodontal health maintenance and gingival recessions development in patients undergoing an orthodontic treatment with clear aligners (CA) and fixed appliances (FA). Material and methods: An electronic search in MEDLINE, Scopus, The Cochrane Library, and Web of Science was performed up to September 2022 to identify all potential articles. Two investigators independently selected the studies according to the inclusion criteria. Prospective and retrospective studies assessing the periodontal health status and gingival recession development during the orthodontic treatment with buccal FA and CA were included. Case series, cross-sectional studies, and studies with less than two months of follow-up were excluded. Two investigators independently extracted the data from included articles and assessed risk of bias across studies using the Cochrane Collaboration tool. Qualitative and quantitative analyses of the data were performed. Pairwise meta-analysis using a random-effects model were used to compare periodontal indices between FA and CA treatment in different follow-up periods. Results: From the 129 potential studies, finally 12 studies were included. Only 8 could be included in the quantitative analysis. CA seems to slightly maintain better periodontal health indices. Only plaque index in a mid-term follow-up (mean difference (MD): -0.99; 95%; Confidence interval (CI) [-1.94 to -0.03]; P=.04; I2=99%), and pocket probing depth at a long-term follow-up (MD: -0.93mm; 95% CI [-1.16 to 0.7]; P<0.0001) reported statistically significant results favoring CA. Conclusions: Up to the date there is not enough evidence to conclude that CA maintains better periodontal health during an orthodontic treatment than FA. (AU)

Investigation of the cleaning performance of commercial orthodontic cleaning tablets regarding biofilm removal on PMMA test specimens : An ex vivo study.

PURPOSE: The purpose of this ex vivo study was to compare the cleaning performance of three commercially available orthodontic cleaners on polymethyl methacrylate (PMMA) test specimens covered with biofilm. METHODS: Twenty subjects wore an individually manufactured vacuum-formed maxillary splint with four integrated PMMA test specimens for 7 days. The four test specimens were located on the buccal surfaces of the maxillary molars. After a 7-day wearing period, the PMMA test specimens colonized by biofilm were divided into two halves. One half was placed in 150 ml of tap water or in 150 ml of cleaning solution of the cleaners Retainer Brite® (Dentsply International Raintree Essix, Sarasota, FL, USA), Kukis® Xpress (Reckitt Benckiser, Heidelberg, Germany) or Dontodent (Propack, Heidelberg, Germany) while the other half remained uncleaned. The modified o­phthaldialdehyde (OPA) method was used to determine the amount of protein on both halves of the test specimens. The difference was tested for significance as a measure of the cleaning effect using a paired sample t­test. RESULTS: The cleaning performance of the three orthodontic cleaners was higher than the cleaning performance of tap water (mean 25.9 ± 6.5%). While Retainer Brite® (mean 54.5 ± 7.1%) removed significantly more biofilm than Dontodent (mean 41.5 ± 9.2%, p < 0.001) and Kukis® Xpress (mean 39.9 ± 11.5%, p < 0.001), there was no significant difference in the cleaning performance between Kukis® Xpress and Dontodent (p = 1). CONCLUSION: Seven-day-old biofilm is only removed partially by the investigated orthodontic cleaners, so that they are not suitable as the only measure for removing established biofilms.

Color changes of nanocomposites used for clear aligner attachments: an in vitro study.

PURPOSE: The purpose of this study was to compare the color changes of two different nanocomposites used for two different designs of clear aligner attachments. METHODS: In all, 120 human premolars were embedded in 12 upper dental models with 10 premolars in each model. Models were scanned and attachments were digitally designed. Conventional attachments (CA) were prepared for the first six models and optimized multiplane attachments (OA) were prepared for the other six models with packable composite (PC) on the right quadrant and flowable composite (FC) on the left quadrant of each model. The models were subjected to 2000 thermal cycles at 5 °C/55 °C and then consecutively immersed in the five different staining solutions each for 48 h to simulate external discoloration. Color measurements were taken with a spectrophotometer. Color changes (∆E*ab) of the attachments before and after immersion were compared with the Commission Internationale de l'Éclairage L*a*b* (CIELAB) color space approach. RESULTS: When ∆E*ab values were examined, no significant difference was observed between the groups according to the attachment type (P > 0.05). After the coloration process, the flowable composite group showed less coloration than the packable composite group for both attachment designs (P < 0.05). Color difference values after the staining procedure were significantly higher in the CA-PC and OA-PC groups compared to the CA-FC and OA-FC groups (P < 0.05). CONCLUSION: Color change of the packable nanocomposite was more pronounced than that of the flowable nanocomposite for both attachment designs. Therefore, clear aligner attachments created using flowable nanocomposite can be recommended, especially in the anterior region where esthetics are important for the patient.

Fixed and removable orthodontic retainers, effects on periodontal health compared: A systematic review.

The aim of this systematic review is to analyze the properties of the different types of orthodontic retainers, identify their differences and define which type of device is most effective and less harmful to periodontal health. Methods: A literature search was carried out by a reviewer by consulting PubMed, Lilacs, Embase, Medline full text, Scopus, Web of Science, Cochrane library, and Science Direct electronic databases for biomedical and health literature as well as the grey literature and setting up the search from December 2010 without any restriction about articles languages. Results: The results showed that patients who wear retainers for a long period have significant differences in clinical parameters compared to patients without retainers. The type of retainer chosen also significantly influences the overall periodontal health of patients. Fixed retainers, both glass-fibre reinforced and steel wire retainers, proved to be the retainer type with the highest plaque and calculus accumulation values compared to removable retainers. In addition, among fixed retainers, glass-fibre reinforced retainers proved to be those that mostly promote the plaque and calculus accumulation in the application site. Conclusion: Fixed retainers are the best devices to maintain the alignment of mandibular anterior teeth in the long term. Among these devices, stainless steel lingual retainers, plain or braided, should remain the first choice. Although they are also susceptible to periodontal complications, their effect on periodontal health can be considered statistically insignificant if compared to glass-fibre reinforced retainers which, showing worse periodontal complications, should not be used.

Treatment of skeletal class III malocclusion using a combined clear aligner and surgery-early approach : Assessment based on the American Board of Orthodontics Objective Grading System.

PURPOSE: To evaluate whether clear aligner therapy (CAT) combined with a surgery-early approach can achieve good therapeutic effects in patients with skeletal class III malocclusion. METHODS: Thirty consecutive skeletal class III malocclusion cases treated with clear aligners combined with early surgery were selected. Treatment time, lateral cephalograms and American Board of Orthodontics Objective Grading System (ABO-OGS) scores of the treatment models were measured to evaluate the treatment efficiency, facial profile, and occlusion. RESULTS: The results showed that early surgery was achieved after 7.71 months of presurgical orthodontics, on average. ANB decreased by 5.57° (P < 0.001), and STissue N Vert to Pog' decreased by 7.29 mm (P = 0.001), both reaching normal values. The posttreatment ABO-OGS scores were 26.600 on average, meeting its standards. CONCLUSIONS: With the assistance of CAT, early surgery can be accomplished in patients with skeletal class III malocclusion, improving their facial profile and achieving functional occlusion.

Guia prático da fabricação de alinhadores inhouse ­ Parte 2: Planejamento e Estagiamento / Practical guide to inhouse aligner fabrication ­ Part 2: Planning and Staging

Resumo Movimentos ortodônticos realizados com alinhadores in-house possuem detalhes e particularidades que os diferem da mecânica ortodôntica convencional multi-bráquetes e que precisam ser respeitados pelo ortodontista na busca pela maior previsibilidade, eficácia e eficiência dos resultados. Detalhes quanto ao tipo de movimento programado para cada dente, controle de ancoragem, hierarquização das movimentações, peculiaridade da mecânica das variadas composições dos plásticos e tipos de attachments são apresentados nesta segunda parte do tutorial sobre a fabricação de alinhadores in-house (AU)

Abstract Orthodontic movements with in-house aligners entail specific details and nuances that distinguish them from traditional multi-bracket orthodontic techniques. The orthodontist must acknowledge these details to ensure greater predictability, efficacy, and efficiency in achieving desired outcomes. This second part of the in-house aligners manufacturing tutorial presents insights on tooth-specific movement requirements, anchorage control, movement hierarchy, unique aspects of plastic mechanics, and attachment types (AU)

Elastodontic Devices in Orthodontics: An In-Vitro Study on Mechanical Deformation under Loading.

The purpose of the present study was to evaluate the mechanical resistance of elastodontic devices (ED): their maximum compression loads and plastic deformation under loading (percentage). An Instron universal machine (Model 3365, Instron, Industrial Product Group, Grove City, PA, USA) was employed with a 100 N load cell and with Bluehill software for loading analyses. Each device was submitted to a five-cycles test. The following ED were evaluated: A.M.C.O.P. (Micerium, Genova, Italy) in red color, in orange color, and in blue color; HealthyStart (Ortho-Tain, Winnetka, IL, USA), and T4K™ phase 1 (Myofunctional Research Co., Helensvale, Australia). During the five-cycles test, the Ortho-Tain device delivered the greatest compression load (7.56 N), with the lowest percentage of deformation (0.95%). For all devices, a slight plastic deformation of the material was registered, ranging from 0.95% to 1.75%. For the T4K device it was not possible to complete the five-cycles test. For all the analyzed ED, a slight plastic deformation under loading was registered, that in all cases can be considered clinically acceptable. Further studies are needed to test the appliances after clinical usage.

Treatment of Class III Malocclusion and Anterior Crossbite with Aligners: A Case Report.

The article describes the orthodontically treated case of a 25-year-old patient with skeletal and dental class III malocclusion, anterior crossbite, which caused functional and aesthetic problems, occlusal trauma, and incisor wear. Treatment with transparent aligners was proposed to meet the patient's needs, using the sequential distalization protocol. While sequential distalization is well documented for class II malocclusion treatment in maxillary arch teeth, further investigations are necessary for class III malocclusions. In fact, lower teeth movements are more complex due to mandibular bone density and the presence of the third molars, which are often extracted to perform distalization. In addition, the use of intermaxillary elastics helps control the proclination of the anterior teeth as a reaction to distalizing forces. At the end of the treatment, the patient reached molar and canine class I and positive overjet and overbite. The inclination of lower incisors and the interincisal angle have improved, resulting in aesthetic and functional enhancement.

Efeito das irradiações ultravioleta (UV) e light emitting diode (LED) nas propriedades mecânicas dos alinhadores transparentes de poliuretano (PU) / Effect of ultraviolet (UV) and light emitting diode (LED) irradiations on the mechanical properties of transparent polyurethane (PU) aligners

O objetivo do presente estudo in vitro é investigar possíveis alterações nas propriedades mecânicas de alinhadores transparentes de poliuretano (PU). Em um estudo piloto, amostras de alinhadores foram submetidas à Espectroscopia Raman antes e depois de irradiações de UV e de LED, e os resultados demonstraram evidente alteração da estrutura molecular. Em virtude disso, foi levantada a hipótese de que as radiações também provoquem alterações nas propriedades mecânicas. Foram confeccionados trinta alinhadores, pela empresa Align Technology Inc. (Invisalign ®), distribuídos em três grupos de dez alinhadores cada. Um grupo controle não sofreu irradiação, e os outros dois grupos foram irradiados: um com radiação UV dentro de uma câmara construída para esse tipo de experimento e um terceiro grupo com radiação LED por fotopolimerizador específico. Os grupos foram definidos, as irradiações foram efetuadas sob sigilo por um operador e as identificações, armazenadas em envelopes lacrados, somente foram reveladas após a conclusão dos testes e tabulação dos dados obtidos. Para avaliação das propriedades mecânicas, neste caso resistência à deformação, utilizou-se uma máquina de ensaio universal para o teste de carga. Os alinhadores foram preenchidos com gesso, com um alívio que deixou livres as áreas a serem testadas. O teste de tensão mostrou que tendo como referência o grupo controle, os alinhadores submetidos à radiação UV tornaram-se menos rígidos e os submetidos à radiação LED tornaram-se mais rígidos. O teste de H de Kruskal-Wallis foi realizado e evidenciou não haver diferença estatisticamente significativa na carga aplicada nas amostras dos diferentes grupos. O mesmo teste foi utilizado para avaliar a diferença entre a deformação ocorrida e o módulo de elasticidade nos três grupos. A hipótese nula foi rejeitada em ambos os testes, considerando o nível de 5% de significância, o que assegura que há uma diferença significativa entre os três grupos quanto à irradiação de UV ou LED. Ainda assim, para uma avaliação mais minuciosa utilizou-se o teste de Mann-Whtiney comparando os grupos dois a dois. O resultado apontou que as irradiações aplicadas neste estudo são responsáveis pelas diferenças estatísticas apresentadas. (AU)

The aim of the present in vitro study is to investigate possible changes in the mechanical properties of transparent polyurethane (PU) aligners. In a pilot study, specimens of aligners were subjected to Raman Spectroscopy before and after UV and LED irradiation, and the results showed evident alteration of the molecular structure. Because of this, it was hypothesized that the radiations also cause changes in the mechanical properties. Thirty aligners were made by Align Technology Inc. (Invisalign®), distributed in three groups of ten aligners each. A control group was not irradiated, and the other two groups were irradiated: one with UV radiation inside a chamber built for this type of experiment, and the third group with LED radiation by a specific photopolymerizer. The groups were defined, the irradiations were done under confidentiality by an operator and the identifications, stored in sealed envelopes, were only revealed after the completion of the tests and tabulation of the data obtained. To evaluate the mechanical properties, in this case resistance to deformation, a universal testing machine was used for the load test. The aligners were filled with plaster, with a relief that left free the areas to be tested. The tension test showed that taking the control group as reference, the aligners submitted to UV radiation became less rigid and those submitted to LED radiation became more rigid. The Kruskal-Wallis H test was performed and showed that there was no statistically significant difference in the load applied to the samples of the different groups. The same test was used to evaluate the difference between the deformation occurred and the modulus of elasticity in the three groups. The null hypothesis was rejected in both tests, considering the 5% significance level, which ensures that there is a significant difference between the three groups regarding UV or LED irradiation. Even so, for a more detailed evaluation the Mann-Whtiney test was used, comparing the groups two by two. The result pointed out that the irradiations applied in this study are responsible for the statistical differences presented (AU)

Escolha de attachment para alinhadores "in office" / Choosing attachment for "in office" aligners

Resumo A escolha de attachments é uma das estratégias disponíveis para aumentar a área de pressão do alinhador com o dente, criando maior retenção e gerando vetores de força adicionais na direção do movimento desejado no planejamento virtual com alinhadores "in office" (AIO). Devem ser considerados como importantes elementos auxiliares desta modalidade ortodôntica, gerando maior previsibilidade e segurança ao tratamento ortodôntico. Dessa forma, o objetivo desse artigo é fornecer informações sobre o uso dos attachments mais comumente utilizados para o planejamento virtual de AIO, de acordo com a movimentação dentária. O alinhador recobre toda a superfície dentária, com isso, este dispositivo apresenta uma capacidade única de aplicar forças compressivas em todas as direções. Porém observando sua desvantagem de tensão e deformação do material plástico, constata-se a necessidade de incluir attachments com pré-requisitos distintos e conceitos biomecânicos variados. Foram realizadas simulações ilustrativas no software Archform (San Jose, EUA), de acordo com os tipos de attachments e respectivas características para favorecer o movimento planejado. Pontos cruciais como o formato, tamanho, localização, orientação e anatomia dentária influenciam a eficiência do alinhador, e foram abordados para a respectiva conduta de escolha dos attachments frente aos movimentos variados. Desta forma, para maior assertividade por parte do ortodontista na movimentação dentária que se deseja aplicar, torna-se imprescindível conhecer os tipos de attachment e suas principais indicações clínicas. (AU)

Abstract Choosing attachments is one of the available strategies to increase the pressure area of the aligner with the tooth, creating greater retention and generating additional force vectors in the direction of the desired movement in the virtual planning with "in office" aligners (IOA). They should be considered as important auxiliary elements of this orthodontic modality, obtaining greater predictability and security for the orthodontic treatment. Thus, the aim of this article is to provide information on the use of the most commonly used attachment for virtual IOA planning, according to the desired tooth movement. The aligner covers the entire tooth surface and, with that, this device has a unique ability to apply compressive forces in all directions. However, observing its disadvantage of tension and deformation of the plastic material, it is verified the need to include an attachment with pre-adjustment different requirements and biomechanical concepts. Illustrative simulations were carried out in the Archform software (San Jose, USA), according to the types of attachmentes and their characteristics to favor the planned movement. Crucial points such as format, size, location, orientation, and dental anatomy influence the efficiency of the aligner, and were addressed for the respective conduct of choosing the attachmentes in varied movements. Thus, in order for the orthodontist to be more assertive with the desired tooth movement, it is essential to know the types of attachment and their main clinical indications. (AU)

What Are the Cleaning and Disinfection Methods for Acrylic Orthodontic Removable Appliance? A Systematic Review.

(1) Background: The use of removable orthodontic appliances, which is common in early ages, requires careful hygiene, as several different microorganisms are found on their surface during the orthodontic treatment. (2) Methods: Comprehensive electronic searches were conducted up to May 2021. Randomized controlled trials (RCTs) or controlled clinical trials (CCTs), prospective or retrospective, evaluating the efficacy of cleaning and disinfection methods for acrylic removable orthodontic appliances, redacted in the English language, were included. Three independent blinding review authors were involved in study selection, data extraction, and bias assessment. (3) Results: A total of 2491 records were screened and eight studies (six RCTs and two CCTs) fulfilled the inclusion criteria. Among the overall cleaning and disinfection methods described in the included studies, four categories could be defined: liquid antimicrobial agents, commercial tablet cleansers, natural plant extracts and incorporation of quaternary ammonium methacryloxy silicate, all of which demonstrated superior efficacy compared to the placebo/negative control. However, the different methods were not compared with each other. (4) Conclusions: Biofilm control on acrylic orthodontic removable appliances can be performed using the different cleaning and disinfection methods considered in the included studies. Further studies are needed to define the most effective technique. Registration: PROSPERO CRD 42021269297.

Short-term effects of the orthodontic removable traction appliance in the treatment of skeletal Class III malocclusion: A randomized controlled trial.

BACKGROUND: The orthodontic removable traction appliance (ORTA) was introduced as an intraoral removable appliance to treat Class III patients, but the pure treatment effects of ORTA have not been established yet. OBJECTIVES: The aim of the study was to evaluate the skeletal, dental and soft tissue changes following the use of ORTA in treating Class III growing patients, and to compare these changes with those observed in an untreated control group (UCG). MATERIAL AND METHODS: Forty-two patients with Class III malocclusion (mean age: 9.04 ±0.84 years) were randomly allocated to either the intervention group (ORTA) or UCG with a 1:1 allocation ratio. The patients in the ORTA group were treated until a positive overjet was achieved, whereas those in UCG were observed for an average of 6 months. Lateral cephalograms were obtained before (T1) and at the end of the treatment or observation period (T2). Twenty-six variables were used to evaluate treatment changes. The paired and independent t tests were used to detect significant differences within and between the groups, respectively. RESULTS: Forty-two patients who met the inclusion criteria were included primarily. Two patients in UCG dropped out of the study. Therefore, 40 patients were included in the statistical analyses (ORTA: 21; UCG: 19). The orthodontic removable traction appliance was able to correct Class III malocclusion in a mean treatment time of 4.34 ±2.02 months. The maxilla moved forward by a mean of 1.31°, which was significantly greater than in the case of UCG (i.e., a mean difference of 1.02°). The mandible moved significantly backward in the ORTA group (the mean change in SNB: -1.85°) and significantly forward in UCG (the mean change in SNB: 0.97°), leaving the overall sagittal skeletal change significantly greater in the ORTA group as compared to UCG (the mean change in ANB: 3.81°) (p < 0.001). CONCLUSIONS: In the short term, ORTA seemed to be an effective intraoral removable appliance in the treatment of growing Class III patients.

Frequency of Pathogenic Microorganisms in Removable Orthodontic Appliances and Oral Mucosa in Children.

OBJECTIVE: The aim of this study was to evaluate the frequency of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida species in removable orthodontic appliances (ROA) and the support oral mucosa in children. STUDY DESIGN: The study participants comprised 55 patients aged 6-12 years requiring ROA. The samples of biofilm colonization from the support oral mucosa and the ROA were taken prior to the use of the ROA (T0) and 4 weeks (T1) after ROA placement. The biofilm samples were seeded on chromogenic culture plates and incubated for 24-48 h. RESULTS: The microbial species evaluated were not present in either the support oral mucosa nor in the ROA at T0. After 4 weeks, P. aeruginosa was found in the support oral mucosa with a frequency of 60%, Candida spp. with 30.9% and S. aureus with 89.09%; in the ROA, P. aeruginosa with 67.7%, Candida spp. with 32.7%, while S. aureus with 90.9%. In the ROA were found C. glabrata in 15 cases, C. albicans in 14 cases, C. tropicalis in two cases, and C. krusei in one case. In the oral mucosa there were 10 cases of C. glabrata, 14 cases of C. albicans, one case of C. tropicalis, and 0 cases of C. krusei. CONCLUSIONS: The frequency of S. aureus, P. aeruginosa, and Candida spp. increased after the orthodontic treatment in either the ROA and or in the support oral mucosa. There is a direct relation between the use of the ROA and the increase of periodontal-pathogenic microorganisms.

Short-Term Effect of Orthodontic Treatment with Clear Aligners on Pain and sEMG Activity of Masticatory Muscles.

Background and objectives: The aim of this study is to evaluate mandibular elevator muscles activity and pain on palpation in the early stages of orthodontic treatment with clear aligners using surface electromyography (sEMG). Materials and methods: Surface electromyography (sEMG) activity and pain level on muscle palpation of masseter and anterior temporalis muscles were recorded in a sample of 16 adult subjects (aged 18-32 years; mean 22.5 +/- 3.5 SD) undergoing orthodontic treatment with clear aligners before the treatment (T0), after 1 month of treatment (two clear aligners) (T1), and after 3 months of treatment (T2) (six clear aligners). A chi-square test for nominal data, a Friedman test, and a Wilcoxon-signed rank test as post hoc analysis were applied. Results: No statistically significant differences in muscular pain were observed. At T1, the sEMG activity of masseter muscles at mandibular rest position showed a statistically significant reduction, but after 3 months (T2), the data appeared similar to T0 (p = 0.03 and p = 0.02). Conclusions: During the treatment with clear aligners, subjects could experience an initial reduction in the masseter basal activity after 1 month of treatment. This effect tends to decrease to baseline levels after 3 months of therapy.

Eficácia do pacote Invisalign Lite no tratamento do apinhamento anterior: percepção de ortodontistas e leigos / Efficacy of Invisalign Lite package in the anterior crowding treatment: orthodontist and lay people perception

Resumo O objetivo da pesquisa foi avaliar a eficácia do pacote Invisalign Lite no tratamento de apinhamentos anteriores suaves e moderados sob a perspectiva de ortodontistas e leigos. Dez indivíduos tratados com Invisalign Lite foram selecionados consecutivamente e divididos em dois grupos: menos de 2mm de apinhamento (suave) e mais que 2mm e menos que 5mm de apinhamento (moderado). Imagens do modelo digital pré e pós-tratamento de cada paciente foram obtidas e organizadas randomicamente em uma apresentação Power Point. A avaliação foi realizada por 109 indivíduos divididos em dois grupos: ortodontistas e leigos. A eles foi solicitado que atribuíssem uma nota de 1 (pobre) a 5 (excelente) para o alinhamento dos dentes em cada imagem. Ainda os avaliadores tinham que responder para cada uma das imagens, se na opinião deles o tratamento ortodôntico era necessário. Em todos os grupos foi realizado o teste de normalidade Kolmogorov-Smirnov. O teste-t pareado e o teste não paramétrico Wilcoxon foram utilizados para comparações pareadas. O teste-t independente e o não-paramétrico Mann-Whitney foram utilizados para comparar os grupos de avaliadores e de quantidade de apinhamento. O nível de significância de 5% (P<0,05) foi adotado para todos os testes. Para os ortodontistas, a avaliação do alinhamento dentário subiu de 2,85 para 4,13 após o tratamento ortodôntico. Já para os leigos, a nota subiu de 2,54 para 3,69. De acordo com os ortodontistas, 11,15% das imagens pós-tratamento necessitava de tratamento ortodôntico. Já de acordo com os leigos, essa porcentagem foi de 35,63%. (AU)

Abstract The aim of the research was to evaluate the efficacy of Invisalign Lite package in mild and moderate anterior crowding treatment from the perspective of orthodontists and lay people. Ten subjects treated with Invisalign Lite were consecutively selected and divided into 2 groups: less than 2mm crowding (mild) and more than from 2mm to 5mm crowding (moderate). Images pre-and post-treatment of each subject were obtained from digital cast and randomly arranged in a Power Point presentation. The evaluation was performed by 109 individuals divided into 2 groups: orthodontists and lay people. They were asked to assign a score for teeth alignment from 1 (poor) to 5 (excellent). Also, the evaluators had to answer for each of the images, if in their opinion orthodontic treatment was necessary. In all groups the Kolmogorov-Smirnov normality test was performed. Paired t-test and non-parametric Wilcoxon test were used for paired comparison. The independent t-test and non-parametric Mann-Whintney were used for comparing evaluators groups and the amount of crowding. In all tests a 5% (p<0,05) significance level was adopted. For the orthodontists, alignment evaluation increased from 2,85 to 4,13 after orthodontic treatment. The scores assigned by lay people increased from 2,54 to 3,69. Orthodontists pointed out that they would indicate orthodontic treatment for 11,15% of the post-treatment images. For lay people, orthodontic treatment would be necessary for 35,63% of post-treatment images.(AU)

Ativação de alinhadores ortodônticos com alicates ­ uma alternativa para obtenção de resultados / Activation of orthodontic aligners with pliers ­ an alternative to obtain the results

Resumo A grande procura por estética tem levado ao desenvolvimento de aparelhos ortodônticos cada vez mais discretos. Por isso, os tratamentos com alinhadores ortodônticos têm se tornado uma realidade na clinica diária e o entendimento de sua biomecânica e principalmente dos recursos para obtenção dos resultados almejados é de fundamental importância. Diante disso, este trabalho tem como objetivo demonstrar como a ativação dos alinhadores através dos alicates ortodônticos pode ser realizada de forma a ajudar no complemento da movimentação, principalmente quando somente a força exercida pelos alinhadores não é suficiente para a completa movimentação dentária desejada (AU)

Abstract The great demand for aesthetics has led to the development of increasingly discreet orthodontic appliances. For this reason, treatments with orthodontic aligners have become a reality in daily practice and the understanding of their biomechanics and especially the resources to obtain the desired results is of fundamental importance. Therefore, this work aims to demonstrate how the activation of the aligners through orthodontic pliers can be performed in order to help complement the movement, especially when only a force exerted by the aligners is not sufficient for the desired tooth movement (AU)

The impact of general self-efficacy and the severity of malocclusion on acceptance of removable orthodontic appliances in 10- to 12-year-old patients.

BACKGROUND: The patients' acceptance of a treatment plan and their subsequent cooperation play a crucial role in achieving the best results in orthodontic treatments. Evidences show some personality traits such as general self-efficacy (GSE) and some dental traits such as severity of malocclusion are correlated with motivation of orthodontic treatment. These factors may predict the patients' compliance and acceptance in using removable orthodontic appliances. This cross sectional study was conducted to assess the correlation of GSE and the severity of malocclusion with patients' acceptance in using removable orthodontic appliances. METHODS: This study recruited 50 patients aged 10-12 years who required removable orthodontic appliances. The severity of malocclusion was determined using the index of orthodontic treatment need (IOTN) before the onset of treatment and GSE of participants were assessed using GSE scale self-report. The acceptance questionnaire was proposed to the patients on first (T1), third (T2), and sixth (T3) month after the delivery of the appliance. RESULTS: The GSE score had a statistically significant correlation with the total score of the acceptance questionnaire, subscale score of satisfaction with the appliance during eating and oral hygiene practice, duration of usage of the appliance, and interest in using it (P < 0.05). The IOTN had no significant correlation with the acceptance questionnaire. CONCLUSIONS: Our findings substantiate the role of the GSES, concurrently declining the role of the IOTN in prediction of 10-12-year-old children's acceptance and cooperation in treatment of malocclusion with removable appliances.

Space closure using aligners

ABSTRACT Introduction: Due to the search for more aesthetic and comfortable alternatives to perform orthodontic treatments and to the great technological development, orthodontic aligners have assumed great importance. More and more complex treatments have been carried out with these appliances without, however, having all aspects involved in their use being studied in depth. Its biomechanical planning requires different approaches than those used in fixed orthodontics, as the force systems involved in movements, responses and side effects are distinct, and the professional must be prepared when opting for the technique. Objective: The objective of this article is to perform an evaluation of the force systems created on the space closure with aligners, its characteristics, and problems, as well as make some suggestions to overcome the difficulties inherent to its use. Conclusion: Space closure with aligners is possible, but depends on the correct selection of the patient, in addition to requiring the proper planning of the applied forces. The use of auxiliary resources and overcorrections to address the deficiencies of the aligner systems should always be considered. Digital planning should be used as a map of the force systems that will be applied, and not just as a marketing tool, keeping in mind that determining the objectives and the way to achieve them is the responsibility of the orthodontist, and that treatment plans must be individualized for each situation, following appropriate biomechanical precepts.

RESUMO Introdução: Devido à busca por alternativas mais estéticas e confortáveis para realizar tratamentos ortodônticos e ao grande desenvolvimento tecnológico, os alinhadores ortodônticos assumiram uma grande importância. Tratamentos cada vez mais complexos vêm sendo realizados com esses dispositivos sem que, no entanto, sejam estudados em profundidade todos os aspectos envolvidos na sua utilização. Seu planejamento biomecânico requer abordagens diferentes da Ortodontia fixa, pois os sistemas de forças envolvidos nas movimentações, respostas e efeitos colaterais são distintos, e o profissional deve estar preparado ao optar por essa técnica. Objetivo: O objetivo deste artigo é fazer uma avaliação dos sistemas de forças envolvidos no fechamento de espaços com alinhadores, suas características e problemas, bem como apresentar algumas sugestões para contornar as dificuldades decorrentes de seu uso. Conclusão: O fechamento de espaços com alinhadores é possível, mas depende da correta seleção do paciente, além de exigir o adequado planejamento das forças aplicadas. O uso de recursos auxiliares e sobrecorreções para suprir as deficiências dos sistemas de alinhadores deve ser sempre considerado. O planejamento digital deve ser usado como um mapa dos sistemas de forças que serão aplicados, e não apenas como ferramenta de marketing, tendo em mente que a determinação dos objetivos e da maneira de atingi-los é de responsabilidade do ortodontista e que os planejamentos devem ser individualizados para cada situação, seguindo preceitos biomecânicos adequados.