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Abstract Objective: The aim of this study was to compare the cephalometric changes in Class II division 1 malocclusion patients treated with Jones Jig appliance or with maxillary first premolar extractions. Methods: The sample consisted of 88 lateral cephalograms of 44 patients, divided into two groups. Group 1 consisted of 21 patients treated with Jones Jig appliance, with a mean initial age of 12.88 ± 1.23 years and final mean age of 17.18 ± 1.37 years, and a mean treatment time of 4.29 years. Group 2 comprised 23 patients treated with maxillary first premolar extractions, with a mean initial age of 13.59 ± 1.91 years and mean final age of 16.39 ± 1.97 years, and a mean treatment time of 2.8 years. Intergroup treatment changes were compared with t and Mann-Whitney tests. Results: Class II correction in G2 (maxillary first premolar extractions) presented significantly greater maxillary retrusion, reduction of anteroposterior apical base discrepancy, smaller increase in the lower anterior face height and significantly greater overjet reduction than G1 (Jones Jig). Conclusions: Treatment with maxillary first premolar extractions produced greater overjet reduction, but the two treatment protocols produced similar changes in the soft tissue profile.

Introduction: Fixed orthodontic appliances patients suffer limitations on the effective control of biofilm by mechanical methods, bringing the need of a coadjutant in the control of inflammation and oral health improvement.Objective: The aim of this prospective split-mouth blind study was to analyze the effect of a 40% chlorhexidine (CHX) varnish on gingival growth of patients with orthodontic fixed appliances. Methods: Healthy teenage patients with fixed orthodontic appliances and increased gingival volume were recruited (n = 30). Each individual was his own control, having in the maxilla one control side and one treatment side. An application of varnishes occurred on the vestibular area of the upper premolars and first molar crowns, on the control side (placebo varnish) and on the experimental side (EC40(r) Biodentic CHX varnish). The varnishes and sides were randomly chosen and its identification and group was kept by a third party observer and it was not revealed to the researchers and participants until the end of study. In order to establish a baseline registration, digital photographs were taken by a trained photographer before varnish application at baseline (T0), as well as 14 days (T14) and 56 days (T56) after the application. The gingival volume was calculated indirectly using the vestibular areas (mm2) of the upper second premolars' clinical crowns by RapidSketch(r) software, at all study times. The data were analyzed using ANOVA and the Turkey-Krammer test.Results:It was observed, in the final sample of 30 individuals, that at T0, the control and treatment groups were similar. At T14 and T56, a progressive reduction of the clinical crown area was seen in the control group, and an increase in the average area was detected in the experimental group (p < 0,05).Conclusions: The use of 40% CHX varnish decreases the gingival overgrowth in patients undergoing orthodontic treatment. Further studies are necessary to set the action time and frequency of application.

OBJECTIVE: Although much has been investigated about the effects of cervical headgear, there remains some controversy. Therefore, the objective of this systematic review is to disclose the actual effects of the cervical headgear appliance, based on articles of relevant quality.METHODS: A literature review was conducted using PubMed, Web of Science, Embase, Scopus and Cochrane databases. Inclusion criteria consisted of human studies written in English; published between 1970 and 2014; in which only the cervical headgear was used to correct Class II malocclusion; prospective or retrospective; with a clear description of cervical headgear effects; with a sample size of at least 15 individuals. No comparative studies, clinical cases or cases with dental extractions were included and the sample should be homogeneous.RESULTS: Initially, 267 articles were found. A total of 42 articles were selected by title and had their abstracts read. Finally, 12 articles were classified as with high quality and were used in this systematic review.CONCLUSIONS: The cervical headgear appliance proved efficient to correct Class II, Division 1 malocclusion. Its effects consisted in correction of the maxillomandibular relationship by restriction of maxillary anterior displacement; distalization and extrusion of maxillary molars; and slight maxillary expansion.

OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB). Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB). Cone-beam computed tomography (CBCT) scans and a 3D program (Dolphin) assessed changes in transversal width of buccal bone (TWBB) and buccal bone thickness (BBT) before (T1) and 7 months after treatment onset (T2). Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone.

INTRODUCTION: The indirect bonding technique optimizes fixed appliance installation at the orthodontic office, ensuring precise bracket positioning, among other advantages. In this laboratory clinical phase, material and methods employed in creating the transfer tray are decisive to accuracy. OBJECTIVE: This article describes a simple, efficient and reproducible indirect bonding technique that allows the procedure to be carried out successfully. Variables influencing the orthodontic bonding are analyzed and discussed in order to aid professionals wishing to adopt the indirect bonding technique routinely in their clinical practice.

INTRODUCTION: This study aims to develop a method to assess the changes in palatal and lingual cross-sectional areas in patients submitted to rapid maxillary expansion (RME). METHODS: The sample comprised 31 Class I malocclusion individuals submitted to RME and divided into two groups treated with Haas (17 patients) and Hyrax (14 patients) expanders. Cone-beam computed tomography scans were acquired at T0 (before expansion ) and T1 (six months after screw stabilization). Maxillary and mandibular cross-sectional areas were assessed at first permanent molars and first premolars regions and compared at T0 and T1. Mandibular occlusal area was also analyzed. RESULTS: Maxillary cross-sectional areas increased in 56.18 mm2 and 44.32 mm2 for the posterior and anterior regions. These values were smaller for the mandible, representing augmentation of 40.32 mm2 and 39.91 mm2 for posterior and anterior sections. No differences were found when comparing both expanders. Mandibular occlusal area increased 43.99mm2 and mandibular incisors proclined. Increments of 1.74 mm and 1.7 mm occurred in mandibular intermolar and interpremolar distances. These same distances presented increments of 5.5 mm and 5.57 mm for the maxillary arch. CONCLUSION: Occlusal and cross-sectional areas increased significantly after RME. The method described seems to be reliable and precise to assess intraoral area changes.

Objective: To investigate whether there is scientific evidence to support the hypothesis that the presence of orthodontic fixed appliances influences the oral microbiota. Methods: The search for articles was conducted in PubMed; ISI Web of Knowledge and Ovid databases, including articles published in English until May 17th, 2012. They should report human observational studies presenting the following keywords: "fixed orthodontic appliance" AND "microbiological colonization"; OR "periodontal pathogens"; OR "Streptococcus"; OR "Lactobacillus"; OR "Candida"; OR "Tannerella forsythia"; OR "Treponema denticola"; OR "Fusobacterium nucleatum"; OR "Actimomyces actinomycetemcomitans"; OR "Prevotella intermedia", OR "Prevotella nigrescens"; OR "Porphyromonas gingivalis". Articles were previously selected by title and abstract. Articles that met the inclusion criteria were analyzed and classified as having low, moderate or high methodology quality. A new detailed checklist for quality assessment was developed based on the information required for applicable data extraction for reviews. The study design, sample, follow-up period, collection and microbial analysis methods, statistical treatment, results and discussion were assessed. Results: The initial search retrieved 305 articles of which 33 articles were selected by title and abstract. After full-text reading, 8 articles met the inclusion criteria, out of which 4 articles were classified as having low and 4 as moderate methodological quality. The moderate methodological quality studies were included in the systematic review. Conclusions: The literature revealed moderate evidence that the presence of fixed appliances influences the quantity and quality of oral microbiota.

OBJECTIVE: The present study was designed to verify if mini-implant prototypes (MIP) developed for Herbst appliance anchorage are capable of withstanding orthopedic forces, and to determine whether the flexural strength of these MIP varies depending on the site of insertion (maxilla and mandible). METHODS: Thirteen MIP were inserted in three minipig cadavers (six in the maxilla and seven in the mandible). The specimens were prepared and submitted to mechanical testing. The mean and standard deviation were calculated for each region. A two-way Student's t test was used to compare the strength between the sites. A one-way Student's t test was performed to test the hypothesis. Orthopedic forces above 1.0 kgf were considered. RESULTS: The MIP supported flexural strength higher than 1.0 kgf (13.8 ± 2.3 Kg, in the posterior region of the maxilla and 20.5 ± 5.2 Kg in the anterior region of the mandible) with a significantly lower flexural strength in the anterior region of the mandible (P < 0.05). CONCLUSION: The MIP are capable of withstanding orthopedic forces, and are more resistant in the anterior region of the mandible than in the posterior region of the maxilla in Minipigs br1 cadavers.

OBJECTIVE: The objective of this study was to test the hypothesis that there is no difference between stainless steel and low-nickel stainless steel wires as regards mechanical behavior. Force, resilience, and elastic modulus produced by Quad-helix appliances made of 0.032-inch and 0.036-inch wires were evaluated. METHODS: Sixty Quad-helix appliances were made, thirty for each type of alloy, being fifteen for each wire thickness, 0.032-in and 0.036-in. All the archwires were submitted to mechanical compression test using an EMIC DL-10000 machine simulating activations of 4, 6, 9, and 12 mm. Analysis of variance (ANOVA) with multiple comparisons and Tukey's test were used (p < 0.05) to assess force, resilience, and elastic modulus. RESULTS: Statistically significant difference in the forces generated, resilience and elastic modulus were found between the 0.032-in 0.036-in thicknesses (p < 0.05). CONCLUSIONS: Appliances made of low-nickel stainless steel alloy had force, resilience, and elastic modulus similar to those made of stainless steel alloy.

OBJECTIVE: To compare hysteresis, activation and deactivation forces produced by first-order deformation of Contour 0.014-in NiTi wire (Aditek, Brazil) in four brands of self-ligating brackets: Damon MX, Easy Clip, Smart Clip and In-Ovation. METHODS: Activation and deactivation forces were measured in an Instron universal tensile machine at 3 mm/minute speed to a total displacement of 4 mm. Tests were repeated eight times for each bracket/wire combination. Statistical analysis comprised ANOVA and Tukey's multiple comparisons test. RESULTS: Using a 4-mm deformation, mean activation forces increased in the following order: Damon = 222 gf, Easy Clip = 228 gf, In-Ovation = 240 gf and Smart Clip = 306 gf. The same order was observed for mean hysteresis values, i.e., 128 gf, 140 gf, 150 gf and 206 gf, respectively. The respective values of deactivation forces for the Damon, Easy Clip, In-Ovation and Smart Clip brackets were 94 gf, 88 gf, 90 gf and 100 gf. CONCLUSIONS: Brackets with higher activation forces were accompanied by higher hysteresis values, which resulted in clinically similar deactivation forces, regardless of the type of self-ligating brackets used.OBJETIVO: comparar as forças de ativação, desativação e histerese produzidas por deformação de primeira ordem do fio superelástico Contour NiTi 0,014" (Aditek®) em quatro modelos de braquetes autoligáveis: Damon MX, Easy Clip, Smart Clip e In-Ovation. MÉTODOS: as forças de ativação e desativação foram medidas em máquina universal de tração Instron com velocidade de 3mm/minuto e deslocamento de 4mm. Em cada combinação braquete/fio foram executadas oito repetições. A análise estatística empregou ANOVA e o Teste de Comparações Múltiplas de Tukey. RESULTADOS: com 4mm de deformação, as forças médias de ativação foram, em ordem crescente, Damon = 222gf, Easy Clip = 228gf, In-Ovation = 240gf e Smart-Clip = 306gf; a mesma ordem foi observada nas histereses médias, cujos valores foram, respectivamente, 128gf, 140gf, 150gf e 206gf; os valores das forças de desativação foram, respectivamente, 94gf, 88gf, 90gf e 100gf. CONCLUSÃO: os braquetes com maiores valores nas forças de ativação foram acompanhados por maiores valores na histerese, o que resultou em forças de desativação clinicamente semelhantes, independentemente do tipo de braquete autoligável utilizado.

INTRODUCTION: Plaque control is the major consensus during orthodontic treatment to prevent the occurrence of cavities and periodontal inflammation. The mechanic resource of greater effectiveness and frequent use in this control is the oral hygiene. The tooth brushing techniques most used in orthodontic patients are: Ramfjord's method, Modified Stillman technique and Bass method. OBJECTIVE: Since control studies evaluating the effectiveness of usual tooth brushing techniques do not show clear advantage, the objective of this study was to evaluate the effectiveness of three brushing methods, through periodontal clinical parameters of patients with fixed orthodontic appliances. METHODS: Thirty patients were selected, with ages between 14 and 22 years old, with fixed orthodontic appliances. After basic periodontal treatment the following factors were evaluated: 1 - Plaque index and 2 - Gingival index and each patient was randomly included in one of the three selected groups according to the brushing technique: Group 1 - Scrubbing technique; Group 2 - Modified Stillman technique and Group 3 - Bass technique. Patients were evaluated for 9 months. RESULTS: The results showed a significant reduction of clinical parameters by the end of this period, however there was a very significant reduction of Gingival index on group 3 (13.6%) when compared to the other groups. CONCLUSION: Thus, it can be suggested that the Bass technique can be effective on the reduction of periodontal clinical parameters of Plaque index and Gingival index in patients with fixed orthodontic appliances.INTRODUÇÃO: o controle de placa bacteriana é o maior consenso durante o tratamento ortodôntico para prevenir a ocorrência de cáries e inflamação periodontal. O recurso mecânico de maior efetividade e uso frequente nesse controle é a higienização bucal. As técnicas de escovação dentária mais usadas por pacientes ortodônticos são: a friccional giratória de Ramfjord, a Stillman modificada e a sulcular de Bass. OBJETIVO: tendo em vista que estudos de controle avaliando a efetividade das técnicas de escovação mais comuns não demonstraram nenhuma superioridade clara, o objetivo desse estudo foi avaliar a efetividade de três técnicas de escovação, através dos parâmetros clínicos periodontais de pacientes portadores de aparelhos ortodônticos fixos. MÉTODOS: foram selecionados 30 pacientes, com idades entre 14 e 22 anos, portadores de aparelhos ortodônticos fixos. Após o final do tratamento periodontal básico, determinou-se o (1) Índice de Placa e o (2) Índice Gengival, e cada paciente foi incluído, aleatoriamente, em um dos três grupos, selecionados de acordo com a técnica de escovação (Grupo 1 = Técnica de esfregaço; Grupo 2 = Técnica de Stillman Modificada e Grupo 3 = Técnica de Bass). Os pacientes foram avaliados por um período total de 9 meses. RESULTADOS: os resultados mostraram uma diminuição significativa dos parâmetros clínicos ao final desse período, porém houve uma redução muito significativa do Índice Gengival no grupo 3 (13,6%), em comparação aos demais grupos. CONCLUSÃO: pode-se sugerir que a Técnica de Bass pode ser efetiva na redução dos parâmetros clínicos periodontais de Índice de Placa e Índice Gengival em pacientes portadores de aparelhos ortodônticos fixos.

OBJECTIVE: To evaluate the esthetic perception of different appliances by Brazilian lay adults and its influence in the attributed value of orthodontic treatment, considering evaluators' socioeconomic status, age and gender. METHODS: Eight different combinations of orthodontic appliances and clear tray aligners were placed in a consenting adult with pleasing smile. Standardized frontal photographs were captured and incorporated into a research album. A sample of adults (n = 252, median = 26 years old) were asked to rate each image for (1) its attractiveness on a visual analog scale and (2) the willingness to pay (WTP) for a cosmetic appliance when compared to a standard metalic appliance and a clear tray aligner. Comparisons between the appliances' attractiveness were performed using the Friedman's test and Dann's post-hoc test. Correlation between appliances' attributed value, socioeconomic status, age, gender, and esthetic perception was assessed using Spearman's correlation analysis. RESULTS: Attractiveness ratings of orthodontic appliances varied significantly in the following hierarchy: Clear aligners>sapphire brackets>self-ligating/conventional stainless steel brackets>and golden metal appliances. The correlation between WTP and esthetic perception was week. However, for individuals with better socioeconomic status and aged between 17-26 years old significantly, a significantly higher WTP was found. CONCLUSION: Clear aligners and sapphire brackets with esthetic archwire were considered better esthetic options in this sample. Nevertheless, patients were not willing to pay more money for appliances they deemed more esthetic, however, they were significantly influenced by their socioeconomic level and age.OBJETIVO: avaliar a percepção de brasileiros adultos leigos para diferentes aparelhos ortodônticos e sua influência na valorização econômica do tratamento, considerando o nível socioeconômico, idade e sexo dos avaliadores. MÉTODOS: oito combinações de aparelhos ortodônticos e alinhadores foram colocadas em um adulto com bom alinhamento dentário, e fotografias frontais foram feitas para compor um álbum de imagens de pesquisa. Uma amostra de adultos (n = 252, mediana = 26 anos) classificou cada imagem por (1) atratividade, em uma escala visual analógica, e (2) disposição a pagar a mais para realizar o tratamento com um aparelho estético em relação a um aparelho metálico e em relação a um alinhador. Comparações da atratividade dos aparelhos foram realizadas utilizando-se o teste de Friedman e o post-hoc de Dann. A correlação entre a valorização econômica, nível socioeconômico, idade, sexo e percepção estética foi calculada com a análise de correlação de Spearman. RESULTADOS: a atratividade dos aparelhos ortodônticos variou significativamente, na seguinte hierarquia: alinhadores > aparelhos de safira > aparelhos metálicos tradicionais e autoligáveis > aparelhos dourados. A correlação entre a atratividade dos aparelhos e a disposição em pagar mais por eles foi fraca. Contudo, ter melhor nível socioeconômico e idade entre 17 e 26 anos aumentou significativamente a disposição de pagar dos avaliadores. CONCLUSÕES: alinhadores e braquetes de safira com fio estético foram considerados as opções de maior atratividade para essa amostra. Entretanto, os avaliadores não estiveram dispostos a pagar a mais para realizar seus tratamentos com os dispositivos que julgaram mais estéticos, sendo, contudo, significativamente influenciados por seu nível socioeconômico e idade.

INTRODUÇÃO: o ortodontista clínico deve esperar alguma perda do alinhamento dentário obtido durante o tratamento ortodôntico nos casos em que a contenção ortodôntica foi suspensa pelo profissional ou perdida pelo paciente. Nessa situação, os pacientes são, frequentemente, relutantes em novamente usar braquetes para retratar o alinhamento dentário perdido após o tratamento. OBJETIVO: esse artigo descreve o uso de uma técnica simples e eficiente para corrigir pequenas alterações do alinhamento dentário. Esse procedimento, inovador e de baixo custo, produz a resolução da recidiva em poucas semanas. A força usada para realinhar os dentes é obtida através de um fio elastomérico transparente amarrado a uma contenção fixa, de vários filamentos, colada às arcadas superior e inferior.INTRODUCTION: The clinician should expect some loss of the dental alignment obtained during orthodontic therapy in the long term in cases in which the orthodontic retainer has been removed by the orthodontist or lost by the patient. In this situation, patients are often reluctant to wear braces again to re-treat anterior misalignment. OBJECTIVE: This report describes the successful use of a simple and effective technique to correct mild changes in the incisor alignment after orthodontic treatment. An innovative and low cost procedure effectively solved relapse of anterior misalignment in 1-2 months. The force used to realign the teeth is obtained through the use of a clear elastomeric thread tied to multistranded upper and lower retainers.

OBJETIVO: o presente estudo avaliou clinicamente as condições periodontais de um grupo teste e um grupo controle utilizando-se os seguintes três sistemas de indexação periodontal: índice de biofilme, índice de sangramento e profundidade de sondagem. MÉTODOS: o grupo teste foi composto por 20 indivíduos com média etária de 13,5 anos, submetido ao tratamento ortodôntico fixo, que recebeu duas formas de ligaduras: a elastomérica e a de aço inoxidável. Os resultados foram comparados entre si e com um grupo controle, sem tratamento ortodôntico, composto de 15 indivíduos com média etária de 15,3 anos. As mensurações foram realizadas previamente ao tratamento ortodôntico (T1) e seis meses após a colocação do aparelho ortodôntico fixo (T2); e, no grupo controle, após seis meses da mensuração inicial (T2). Ambos os grupos foram orientados quanto à higiene bucal, segundo a técnica de Bass, antes do início do tratamento. RESULTADOS E CONCLUSÕES: os resultados das análises das faces dentárias demonstraram um aumento estatisticamente significativo nos índices de biofilme (P=0,000), sangramento gengival (P=0,000) e profundidade de sondagem (P=0,000), quando T1 e T2 e os grupos foram comparados; entretanto, não foram encontradas diferenças estatisticamente significativas entre as ligaduras elastoméricas e de aço inoxidável na avaliação desses índices periodontais.OBJECTIVE: This study aimed to conduct a clinical evaluation of the periodontal conditions of a test group and a control group using three periodontal indexing systems, namely: dental biofilm index (DBI), bleeding index (BI) and pocket probing depth (PPD). METHODS: The test group consisted of 20 subjects with a mean age of 13.5 years undergoing fixed orthodontic treatment involving the use of two types of ligature: elastomeric ligature (EL) and stainless steel ligature (SSL). The results were compared with a control group without prior orthodontic treatment, comprising 15 subjects with a mean age of 15.3 years. The measurements were performed prior to orthodontic treatment (T1) and six months after placement of a fixed orthodontic appliance (T2); and in the control group, six months after the initial measurement (T2). Both groups were instructed about oral hygiene, according to the Bass technique, before treatment. RESULTS AND CONCLUSIONS: Dental surfaces showed a statistically significant increase in levels of biofilm (P=0.000), gingival bleeding (P=0.000) and probing depth (P=0.000). When the T1 and T2 groups were compared, however, no statistically significant differences were found between EL and SSL in terms of these periodontal indexes.

OBJETIVO: o objetivo deste estudo foi verificar a fricção no braquete (Roth, Composite, 10.17.005, 3,2mm, largura 0,022" x 0,030", Torque -2° e angulação +13°, Morelli®, Brasil), utilizando fios ortodônticos retangulares de 0,019" x 0,025" de aço inoxidável (Morelli®, Brasil) e de níquel-titânio superelásticos Bioforce com IonGuard e sem IonGuard (Bioforce, GAC®, EUA). MÉTODOS: foram utilizados 24 conjuntos braquetes/segmento de fio, divididos em 3 grupos de acordo com o fio. Cada conjunto braquete/segmento de fio foi testado 3 vezes e obtida uma média. Os ensaios foram realizados em máquina universal de ensaios EMIC DL2000®. Os dados foram submetidos à Análise de Variância com significância de 95%. RESULTADOS: o fio retangular Bioforce com IonGuard apresentou fricção significativamente menor que o Bioforce sem IonGuard, porém sem diferença do fio de aço inoxidável. Entretanto, o coeficiente de variação dos fios Bioforce com e sem IonGuard foi menor que o do fio de aço inoxidável. CONCLUSÃO: os fios retangulares de 0,019" x 0,025" Bioforce com IonGuard apresentam menor fricção que o fio Bioforce sem IonGuard, sem diferença para o fio de aço inoxidável.OBJECTIVE: The aim of this study was to evaluate the friction forces on brackets (Roth, Composite, 10.17.005, 3.2 mm, width 0.022" x 0.030 ", Torque -2° and angulation +13°, Morelli®, Brazil), with stainless steel orthodontic rectangular wire (Morelli®, Brazil) and nickel titanium superelastic Bioforce wires with and without IonGuard (Bioforce, GAC®, USA). MATERIAL AND METHODS: Twenty-four brackets/wire segment combinations were used, distributed into three groups according to the orthodontic wire. Each bracket/wire segment combination was tested three times. The tests were performed in a universal testing machine Emic DL2000®. The data was submitted to ANOVA one way followed by Tukey's post hoc test (p

OBJETIVO: o propósito do presente estudo é avaliar o limite de resistência à flexão de um protótipo de mini-implante desenvolvido para ancoragem do aparelho de Herbst. MÉTODOS: após a realização de um cálculo do tamanho da amostra, quatro corpos de prova contendo os protótipos de mini-implantes foram submetidos a uma força de flexão por engastamento simples, utilizando-se uma máquina universal de ensaios mecânicos, sendo calculado o limite de resistência à força de flexão. RESULTADOS: após os ensaios mecânicos, os novos mini-implantes apresentaram o limite de resistência à força de flexão de 98,2kgf, que foi o menor valor encontrado. CONCLUSÃO: os protótipos de mini-implantes desenvolvidos para ancoragem do aparelho de Herbst foram capazes de suportar forças de flexão maiores do que as forças de mordida descritas na literatura.AIM: The purpose of this study was to evaluate the limit of flexural strength of a mini-implant prototype designed for Herbst appliance anchorage. METHODS: After sample size calculation, four specimens with the new mini-implant were submitted to a single cantilever flexure test using a universal testing machine. The limit of flexural force strength was calculated. RESULTS: The mini-implant prototype showed a limit of flexural force strength of 98.2 kgf (982 N), that was the lowest value found. CONCLUSION: The mini-implant prototype designed for Herbst appliance anchorage can withstand flexural forces higher than the maximum human bite forces reported in the literature.

OBJETIVO: avaliar in vitro e comparar a redução de intensidade das forças liberadas por três grupos de elásticos em cadeia, com diferentes configurações, de um mesmo fabricante, medidas em intervalos de tempo preestabelecidos. MÉTODOS: os segmentos de elásticos em cadeia foram alongados e mantidos ativados durante o experimento com o auxílio de um dispositivo desenvolvido especialmente para esse fim e para possibilitar a leitura das forças. A avaliação da degradação da força foi realizada medindo-se a intensidade da força ao longo do tempo, e calculando-se o percentual de força perdida em relação à força inicial, em cada intervalo de tempo e para cada amostra testada. RESULTADOS E CONCLUSÕES: os dados coletados foram submetidos a análises estatísticas e os resultados demonstraram que, nos momentos seguintes ao inicial, a intensidade da força variou, dentro dos grupos e entre os grupos, nos diferentes momentos. A leitura dos valores das forças remanescentes em cada momento, comparada à referência da força inicial, resultou em valores diferentes, com significância estatística, em todas as comparações efetuadas dentro de cada grupo de elásticos (curto, médio, longo). Após a análise dos resultados das comparações entre os grupos de elásticos em cadeia, conclui-se que, apesar de verificados alguns resultados estatisticamente significativos para a comparação das magnitudes das forças liberadas em cada momento, essas diferenças parecem não ter expressão clínica, demonstrando que, aparentemente, o espaçamento entre os elos não representa uma característica clinicamente significativa na degradação da força ao longo do tempo.OBJECTIVE: To evaluate and compare, in vitro, the decrease in the forces delivered in three groups of elastomeric chains, produced by the same manufacturer, according to the distance between links (short, medium, long). METHODS: The segments of elastomeric chains were stretched and kept activated during the trial using a device developed especially for this purpose, which also allowed force readings. Force degradation was evaluated by measuring force along time and calculating the percentage of force decrease from initial force at each time interval and for each specimen under test. RESULTS AND CONCLUSIONS: Data were statistically analyzed and results showed that at the different time points after initial readings, force intensity varied within and between groups. Readings of remaining forces at each time moment compared with the initial reference force revealed statistically significant differences in all the comparisons in each group of elastics (short, medium, long). Although the comparisons between forces delivered at each time point revealed statistically significant differences, these differences do not seem to have a clinical significance. The space between links does not seem to be a clinically significant characteristic in force degradation along time.

ABSTRACT Objective: The purpose of this study was to evaluate, by means of cephalometric appraisal, the vertical effects of non-extraction treatment of adult anterior open bite with clear aligners (Invisalign system, Align Technology, Santa Clara, CA, USA). Methods: Lateral cephalograms of 30 adult patients with anterior open bite treated using Invisalign (22 females, 8 males; mean age at start of treatment: 28 years and 10 months; mean anterior open bite at start of treatment: 1.8 mm) were analyzed. Pre- and post-treatment cephalograms were traced to compare the following vertical measurements: SN to maxillary occlusal plane (SN-MxOP), SN to mandibular occlusal plane (SN-MnOP), mandibular plane to mandibular occlusal plane (MP-MnOP), SN to mandibular plane (SN-MP), SN to palatal plane (SN-PP), SN to gonion-gnathion plane (SN-GoGn), upper 1 tip to palatal plane (U1-PP), lower 1 tip to mandibular plane (L1-MP), mesiobuccal cusp of upper 6 to palatal plane (U6-PP), mesiobuccal cusp of lower 6 to mandibular plane (L6-MP), lower anterior facial height (LAFH), and overbite (OB). Paired t-tests and descriptive statistics were utilized to analyze the data and assess any significant changes resulting from treatment. Results: Statistically significant differences were found in overall treatment changes for SN-MxOP, SN-MnOP, MP-MnOP, SN-MP, SN-GoGn, L1-MP, L6-MP, LAFH, and OB. Conclusions: The Invisalign system is a viable therapeutic modality for non-extraction treatment of adult anterior mild open bites. Bite closure was mainly achieved by a combination of counterclockwise rotation of the mandibular plane, lower molar intrusion and lower incisor extrusion.