Tomographic evaluation of dentoskeletal changes due to the treatment of class II malocclusion with Forsus appliance.

PURPOSE: This study evaluated dentoalveolar skeletal changes promoted by the Forsus appliance, associated to fixed orthodontic appliance, in the correction of Class II, division 1 malocclusion, from Computed Tomography (CT). METHODS: sample consisted of 10 youngsters (7 males and 3 females), with a mean age of 13.86 years. Two Forsus® models were installed after the alignment and leveling phase of the teeth. Two tomographic images of each patient, T1 and T2 (initial and immediately after removal of Forsus® appliance) were done to perform the anatomical tracings and obtain the variables of interest. The data were described by means and standard deviations. For the comparison between the initial and final phases, the paired "t" test was used and a significance level of 5% was considered (p < 0.05). RESULTS: small skeletal changes were observed, such as posterior maxillary displacement and a slight mandibular growth. Larger dentoalveolar changes occurred as extrusion, retrusion and lingualization of upper incisors; Intrusion, protrusion and vestibularization of the lower incisors; Mesialization and extrusion of lower molars. CONCLUSION: Considering the patients evaluated in this study, Forsus® presented similar results to other mandibular propulsion appliances, with dentoalveolar effects that favored Class II correction, however, with very slight skeletal modifications.

Evaluation of slot height in Roth prescription orthodontic brackets.

The dimensional accuracy of orthodontic brackets slots is extremely important, since inaccuracy can affect orthodontic mechanics. The aim of this study was to investigate the slot heights of Roth prescription brackets from several commercial manufacturers. A total of 360 maxillary and mandibular incisor brackets from 6 different commercial models (Kirium Line, Ovation, Roth Light, Synthesis, Integra, and Miniature Twin) were selected and divided into 18 experimental groups containing maxillary central incisor, maxillary lateral incisor, or mandibular central incisor brackets (n = 20). Brackets were viewed under a scanning electron microscope to acquire a clear image of all slot edges, and slot heights were measured at 2 locations on each bracket to acquire mean values. Group means and standard deviations were calculated and compared with the manufacturer reference value of 0.5588 mm (0.0220 inch) plus or minus a tolerance level of 0.0100 mm (∼0.0004 inch). With the exception of Synthesis maxillary lateral incisor brackets (P = 0.230), all brackets had slot heights that were significantly smaller than 0.5588 mm (P < 0.05). The measured slot heights were 1.84% to 14.91% smaller than the reference value. Virtually all measured bracket slot heights were smaller than claimed by the manufacturers, with great variability within the same brand and indication, revealing a lack of precision in the fabrication process.

Otimização do procedimento de colagem de braquetes ortodônticos utilizando um recipiente fotoprotetor: passo a passo / Optimization of the bonding procedure of orthodontic brackets using a photoprotective vessel: step-by-step

A resina composta fotoativável é usualmente utilizada para o procedimento de colagem de braquetes ortodônticos. No entanto, seu uso requer cuidados antes da fotoativação, pois sua polimerização pode ocorrer precocemente por outras fontes de luz, que não a de um fotoativador dentário (e.g., luz ambiente). Foi idealizado um recipiente fotoprotetor que permite o armazenamento temporário do conjunto de pinças com os braquetes preparados com resina em sua base, evitando o processo de polimerização da resina antes do momento desejado. Objetivo: este estudo tem como objetivo apresentar uma descrição detalhada do procedimento de colagem de braquetes ortodônticos estéticos cerâmicos, quando se utiliza um recipiente fotoprotetor para otimizar o atendimento. Relato de caso: paciente do sexo feminino, 24 anos de idade, submeteu-se ao tratamento ortodôntico em clínica particular. Foram utilizados braquetes ortodônticos autoligados, cerâmicos de alumina policristalina. A colagem dos braquetes foi realizada na arcada inferior de maneira tradicional, porém se fez uso de um recipiente fotoprotetor (protótipo) para otimizar o procedimento. O recipiente teve como finalidade principal o armazenamento temporário de braquetes ortodônticos apreendidos em pinças ortodônticas, já com resina composta para colagem em suas bases. Concluiu-se a instalação do aparelho ortodôntico com a colocação de um arco ortodôntico redondo Ni-Ti 0,014". Considerações finais: a utilização do recipiente fotoprotetor mostrou-se clinicamente eficaz e apresentou um bom resultado final da satisfação tanto do profissional quanto do paciente. O seu uso foi capaz de reduzir o tempo de cadeira do paciente durante o procedimento e impediu a polimerização precoce da resina composta de colagem utilizada. (AU)

The photo-activated resin composite is usually used for the bonding procedure of orthodontic brackets. However, their use requires caution prior to photoactivation, as their polymerization may occur early by light sources other than a dental photoactivator (e.g. ambient light). A photoprotective vessel has been developed to allow temporary storage of the clamps assembly with the resin-prepared brackets, avoiding the polymerization process of the resin prior to the desired moment. Objective: this study purpose was to present a detailed description of the bonding procedure of ceramic orthodontic brackets when using a photoprotective vessel to optimize care. Case report: a 24-year-old female patient underwent orthodontic treatment in a private practice. Orthodontic brackets of polycrystalline alumina ceramics were used for treatment. Bracket bonding was performed in the lower arch in the traditional manner, however a photoprotective vessel (prototype) was used to optimize the procedure. The main purpose of the vessel was the temporary storage of orthodontic brackets- -clamps assembly, already with composite resin for bonding in their bases. The installation of the orthodontic appliance was finished with the placement of a 0.014" round Ni-Ti orthodontic arch. Final considerations: the use of the photoprotective vessel was clinically effective and with a good end result in both professional and patient satisfaction. Its use was able to reduce the patient's chair time during the procedure and prevented the early polymerization of the bonded composite resin used. (AU)

Masticatory evaluation of anterior open bite malocclusion using the colorimetric capsule method.

This pediatric study aimed to assess the masticatory function of patients with anterior open bite through a method that utilizes colorimetric capsules. The sample consisted of 106 patients aged 7-11 years, of whom 51 presented with anterior open bite (experimental group) and 55 presented with normal overbite (control group). The colorimetric capsules used in this evaluation contained basic fuchsin granules, which were used to produce a solution after they were ground during chewing. Each patient was asked to chew 1 capsule for 20 seconds. The absorbance of the obtained solutions was analyzed with a spectrophotometer. Greater masticatory efficiency is directly related to the greater light absorbance of a solution, since light absorbance increases with solution concentration. A nonparametric Wilcoxon test indicated that the solutions obtained from the control group presented significantly greater light absorbance than did those from the experimental group (P < 0.05). Therefore, children with an anterior open bite exhibited less masticatory efficiency than those with a normal overbite.

O efeito de diferentes níveis de PH em soluções de flúor a 1, 1% na corrosão de arcos NITI / The effect of different PH levels on fluoride solutions at 1. 1% on corrosion of NITI archs

Objetivo: Determinar o pH crítico para ocorrer a corrosão de arcos NiTi em soluções de flúor a 1,1%, variando o pH de 3,5 a 7,0. Materiais e Métodos: Doze amostras com 10mm de comprimento de fio superelástico NiTi 0017 x 0025 (Abzil), obtidas do segmento distal dos arcos. As amostras foram aleatoriamente separadas e imersas dentro de recipientes contendo 40ml de seis soluções (água, soluções fluoretadas com pH: 3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5 e 7,0), sob uma mesa agitadora durante 90 minutos. Todas as amostras foram, então, levadas ao MEV. As imagens das amostras imersas em água e soluções fluoretadas com pH 7,0, 6,5 e 6,0 não se apresentaram diferentes, no entanto a partir da solução fluoretada com pH 5,5, as imagens superficiais apresentaram características diferentes dos grupos anteriores. Conclusão: Com base nos resultados obtidos neste estudo, o pH crítico para corrosão de arcos NiTi em soluções de flúor a 1,1% parece estar entre 6,0 e 5,5

Objective: To determine the critical pH to occur corrosion of NiTi arches in 1.1% fluoride solutions by varying the pH between 3.5 and 7.0. Materials and Methods: Twelve samples of 10 mm length superelastic NiTi wire 0017 x 0025 (Abzil) obtained in the distal segment of the arcs. The samples were randomly separated and immersed in 40 ml of six solutions (water, fluoride solutions with pH: 3.5; 4.0; 4.5; 5.0; 5.5; 6.0; 6.5 and 7.0) under a shaker table for 90 minutes. All samples were observed under SEM. The images of the samples immersed in water and fluoride solutions at pH 7.0, 6.5 and 6.0 did not show differences, however from the fluoride solution at pH 5.5, the surface characteristics of images presented differences from above groups. Conclusion: Based on the results obtained in this study the critical pH for corrosion of NiTi arches in fluoride solutions to 1.1% appears to be between 6.0 and 5.5

Analysis on the precision of the dimensions of self-ligating brackets.

OBJECTIVE: The present study aimed to evaluate the precision of the torque applied by 0.022" self-ligating brackets of different brands, the precision of parallelism between the inner walls of their slots, and precision of their slot height. Eighty brackets for upper central incisors of eight trademarked models were selected: Abzil, GAC, American Orthodontics, Morelli, Orthometric, Ormco, Forestadent, and Ortho Organizers. Images of the brackets were obtained using a scanning electron microscope (SEM) and these were measured using the AutoCAD 2011 software. The tolerance parameters stated in the ISO 27020 standard were used as references. The results showed that only the Orthometric, Morelli, and Ormco groups showed results inconsistent with the ISO standard. Regarding the parallelism of the internal walls of the slots, most of the models studied had results in line with the ISO prescription, except the Morelli group. In assessing bracket slot height, only the Forestadent, GAC, American Orthodontics, and Ormco groups presented results in accordance with the ISO standard. The GAC, Forestadent, and American Orthodontics groups did not differ in relation to the three factors of the ISO 27020 standard. Great variability of results is observed in relation to all the variables.

Dentoskeletal and Soft Tissue Effects in the Treatment of Class II Malocclusion with Klammt's Elastic Open Activator.

AIM: The purpose of this study was to evaluate the dentoskeletal and soft tissue effects resulting from treatment with Klammt's elastic open activator (EOA) functional orthopedic appliance in patients with Class II malocclusion characterized by mandibular deficiency. MATERIALS AND METHODS: Teleradiographs were evaluated in the lateral aspect of the initial (T1) and final (T2) orthopedic phases for 16 patients with Class II, Division 1 malocclusion. The age range was from 9 to 11.2 years, with a mean age of 9.9 years. The cephalometric points were demarcated, and cephalometric measurements were obtained by the same investigator to avoid interobserver variability. RESULTS: The EOA promoted increased lower anterior facial height (LAFH), increased effective mandibular length, clockwise rotation of the mandible, retrusion and verticalization of the upper incisors, proclination and protrusion of the lower incisors, extrusion of the upper molars, mesial movement of the lower molars and anterior projection of the lower lip. CONCLUSION: Skeletal changes characterized by an increase in mandibular length and dentoalveolar changes with an emphasis on the verticalization and retrusion of the upper incisors, proclination of the lower incisors and mesial positioning of the lower molars were key to improving the occlusal relationship and esthetic facial factors. CLINICAL SIGNIFICANCE: The EOA is well indicated in patients with Class II malocclusion due to mandibular deficiency with increased overbite, proclined upper incisors and verticalized lower incisors.

Prevalência de dentes supranumerários em pacientes de Ortodontia / Supernumerary teeth prevalence in Orthodontic patients

Existem várias alterações nos arcos dentários, entre estas se encontram as de número, forma e tamanho dos dentes. O dente supranumerário representa um fator etiológico importante e frequente da má oclusão. Este trabalho teve o objetivo de avaliar a prevalência de dentes supranumerários nos pacientes tratados nos cursos de pós-graduação em Ortodontia da Universidade Cidade de São Paulo. A amostra, composta por 1117 radiografias panorâmicas de pacientes que se submeteram a tratamento ortodôntico corretivo, foi estudada quanto à distribuição da prevalência de dentes supranumerários entre os gêneros, os arcos dentários e as regiões bucais. A média de idade da amostra foi de 13,7 anos, sendo que 56% dos pacientes eram do gênero feminino e 44% do masculino. Do total analisada, apenas 18 pacientes (1,61%) apresentaram dentes supranumerários. Em relação ao gênero, verificou-se uma prevalência de 1,9% no gênero feminino, enquanto o gênero masculino apresentou prevalência de 1,2%. Na comparação entre os gêneros não se verificou diferença com significância estatística. No total foram constatados 24 dentes supranumerários, uma vez que existiram radiografias de pessoas com a presença de mais de um dente supranumerário. Destes 24 dentes, 16 estavam no arco superior e 8 no arco inferior. A partir da metodologia aplicada e dos resultados obtidos, pôde-se concluir que: a prevalência de dentes supranumerários foi de 1,61% dos indivíduos da amostra; não se pôde verificar diferença significante na prevalência de supranumerários entre os gêneros masculino e feminino; e a prevalência de dentes supranumerários foi estatisticamente semelhante para os arcos dentários superior e inferior, apesar de 66,7% deles terem sido localizados no arco superior

There are several tooth abnormalities in the dental arches, which can be in the number, shape or size of the teeth. The supernumerary teeth represent an important etiologic factor of malocclusion, quietly frequent. This study aimed to evaluate the prevalence of supernumerary teeth in the patients who has been orthodontic treated in the Graduation course of University of São Paulo City (UNICID). The sample, which consisted of 1117 panoramic radiographs of patients who have undergone orthodontic treatment, was studied on the distribution of the prevalence of supernumerary teeth gender, dental arches and mouth regions. The average age of the sample was 13.7 years, and 56% of patients were female and 44% male. Of the total analyzed, only 18 patients (1.61%) had supernumerary teeth. Regarding to gender, there was a prevalence of 1.9% among females, while males showed prevalence of 1.2%. In comparing genders, there was no statistically significant difference. A total of 24 supernumerary teeth were observed, once existed radiographs from people with more than one supernumerary tooth. Considering these 24 supernumerary teeth, 16 were located in the upper arch, while just 8 were in the lower arch. From the applied methodology and the results obtained, it could be concluded that: the prevalence of supernumerary teeth was 1.61% of individuals in the sample; There was not found significant differences in the prevalence of supernumerary between males and females; and prevalence of supernumerary teeth was statistically similar to the upper and lower dental arches, although 66.7% of them being located on the upper arch

Posicionadores de braquetes ortodônticos ? revisão de literatura e desenvolvimento de um projeto de patente / Orthodontic brackets positioning ? literature review and development of a patent project

Em Ortodontia, a colagem de braquetes é um dos passos mais importantes durante o tratamento, principalmente na técnica Straight Wire, na qual os acessórios possuem uma forma específica para levar cada dente à posição prescrita, no que se refere à inclinação, angulação, ou mesmo adequando a posição vestíbulo-lingual das coroas, que variam devido às suas diferentes espessuras anatômicas. Outro ponto fundamental é a altura na qual os braquetes são posicionados, o que interfere diretamente na oclusão e na estética do sorriso. Se ocorre o posicionamento incorreto dos braquetes, além de contatos prematuros e outros possíveis danos, o profissional despenderá mais tempo realizando dobras compensatórias ou recolagens de acessórios. Assim sendo, o objetivo deste trabalho foi desenvolver e inscrever um projeto de patente, composto por um conjunto de posicionadores de braquetes ortodônticos, no intuito de promover um melhor e mais fácil posicionamento dos braquetes durante a colagem, diminuindo a chance de erros, otimizando o processo e tornando a rotina daclínica ortodôntica mais previsível e eficiente

In Orthodontics, brackets bonding is one of the most important steps during the treatment, especially in Straight Wire technique, in which accessories have an specific shape to led each tooth to its correct position, considering inclination, angulation, or even the buccal-lingual crowns position, that varies according to its thickness. Another important point is the height of the brackets, what interferes directly in the occlusion and in smile aesthetics. When an incorrect positioning of the brackets occurs, the clinician wastes time with rebonding or making wire bends. The aim of this study was to develop and submit a patent project, composed by a kit of brackets positioners, to promote a better and easier positioning during bonding, decreasing the chances of errors, optimizing the process and improving the orthodontic routine, with more predictability and efficiency

The association between periodontal disease and seizure severity in refractory epilepsy patients.

PURPOSE: Periodontal diseases are common in most populations and affect people at all socioeconomic levels. Evidence suggests that patients with epilepsy actually have higher risks of dental disease and increased oral health needs, but the frequency and consequences of poor controlled seizures on dental and periodontal health have not been reported before. We aimed to assess the impact of seizure frequency on periodontal status and oral hygiene in a sample of epilepsy patients. METHODS: One hundred and nine consecutive patients treated for epilepsy at the outpatient clinic of our University Hospital were invited to take part in an oral examination to determine their periodontal disease status, together with a control group. In addition, seizure frequency and use of medication were documented. RESULTS: In logistic regression model, patients were significantly more susceptible to bad oral hygiene, gingivitis and periodontitis that controls (p<0.001); seizure frequency was significantly related to bad oral hygiene (p=0.010), gingivitis (p<0.001) and periodontitis (p<0.001). Tooth brushing habits and presence of caries were associated with oral health in patients group. CONCLUSION: Our study found a significant positive correlation between periodontal disease and seizure severity. Epilepsy patients need to focus more on their oral health and quality of oral hygiene.

Influência do óxido de alumínio na colagem dos bráquetes linguais / The influence of the aluminun oxide on lingual brackets bonding

A descolagem acidental do bráquete é uma severa complicação no decorrer do tratamento ortodôntico, especialmente quando o tratamento é feito com bráquetes linguais. A força de adesão entre o bráquete e o dente é um importante requisito para o sucesso da Ortodontia Lingual na prática diária do consultório. O presente estudo analisou a influência do jateamento do óxido de alumínio na superfície lingual dos dentes antes do condicionamento do esmalte na colagem indireta do aparelho lingual. A força de cisalhamento foi medida 24 horas após a colagem dos bráquetes. Os dentes foram divididos em quatro grupos: G1 - 10 pré-molares com bráquetes da marca American Orthodontics com condicionamento de ácido ortofosfórico a 37%; G2 - 10 pré-molares com bráquetes da marca American Orthodontics com aplicação do jato de óxido de alumínio e ácido ortofosfórico a 37% no esmalte; G3 - 10 pré-molares com bráquetes da marca Ormco com condicionamento de ácido ortofosfórico a 37% e G4 - 10 pré-molares com bráquetes da marca Ormco com aplicação do jato de óxido de alumínio e ácido ortofosfórico a 37% no esmalte. Avaliou-se a resistência ao cisalhamento e observou-se que não ocorreu diferença estatisticamente significante entre os grupos quanto aos diferentes modos de preparo de esmalte. Com relação às marcas comerciais, os bráquetes da American Orthodontics apresentaram resistência à descolagem maior do que os bráquetes da marca Ormco. Concluindo, a resistência à descolagem dos bráquetes não foi aumentada com a aplicação prévia do jato de óxido de alumínio no esmalte hígido, nas duas marcas comerciais de bráquetes.

Accidental bracket debonding is a severe complication throughout orthodontic treatment, especially when using lingual brackets. The bond strength between the bracket and the tooth is an important requirement for the success of Lingual Orthodontics. This study has analyzed the influence of aluminum oxide blasting on the lingual surface of the teeth, before conditioning of the enamel, over indirect bonding of the lingual brace. Shear strength was measured 24 hours after brackets bonding. Teeth were divided into four groups: G1 - 10 premolar teeth with American Orthodontics brackets and 37% orthophosphoric acid conditioning; G2 - 10 premolar teeth with American Orthodontics brackets and application of aluminum oxide and 37% orthophosphoric acid blasting on the enamel; G3 - 10 premolar teeth with Ormco brackets and 37% orthophosphoric acid conditioning; G4 - 10 premolar teeth with Ormco brackets, application of aluminum oxide and 37% orthophosphoric acid blasting on the enamel. When evaluating the shear resistance through mechanical assay, it was not observed statistically significant difference between the groups regarding different enamel preparation modes. Concerning the different commercial brands, the American Orthodontics brackets showed higher debonding resistance than the Ormco brackets. It was concluded that, for both brands of brackets, the resistance to bracket debonding did not increase with the previous application of aluminum oxide blasting on the ename.

Estudo da discrepância osteodentária, pré e pós-tratamento ortodôntico, em más-oclusões de Classe I / Study of bone and tooth discrepancy before and after orthodontic treatment in Class I malocclusions

Esta pesquisa teve como objetivo analisar a discrepância osteodentária nas fases pré e pós-tratamento ortodôntico, em casos de más-oclusões de Classe I. Foram selecionados modelos de estudo em gesso de 25 pacientes (19 do sexo feminino e seis do sexo masculino) com médias de idade de 14,2 anos ± 3,2 ao início do tratamento e 17,6 anos ± 2,7 ao final. Todos tiveram más-oclusões de Classe I tratadas sem extrações dentárias. Um examinador calibrado realizou mensurações das larguras mesiodistais dos dentes e do perímetro do arco mandibular com um paquímetro digital Mitutoyo, com precisão de 0,01 mm, por duas vezes. Foram calculados os valores mínimo e máximo, bem como medianas, médias e desvios-padrão das discrepâncias osteodentárias pré e pós-tratamento ortodôntico. A reprodutibilidade das mensurações foi avaliada pelo teste t de student pareado (α = 0,05). Não houve diferenças estatísticas entre a primeira e a segunda mensuração, indicando boa reprodutibilidade. Em, pelo menos, 60% dos casos ocorreu redução da discrepância de modelo para valores clinicamente aceitáveis. Na fase inicial do tratamento, 50% da amostra apresentavam falta de espaço no arco dentário mandibular (mediana: -0,54 mm). A discrepância média também foi negativa (média: -0,16 mm ± 3,36). Ao final, mediana (0,63 mm) e média (0,65 mm ± 0,85) foram positivas e mais próximas, denotando acréscimo aceitável de espaço na maioria dos arcos dentários. Concluiu-se que o tratamento ortodôntico melhorou as condições de espaço nos arcos dentários mandibulares, reduzindo discrepâncias negativas de até 4 mm e discrepâncias positivas de até 9 mm, sem a necessidade de exodontias.

The aim of this study was to analyze pre- and post-treatment bone and tooth discrepancy in Class l malocclusions. Study casts from 25 patients (19 females, six males) with mean ages of 14.2 years ± 3.2 at the beginning of treatment and 17.6 years ± 2.7 at the end were selected. All of them had their malocclusions treated without tooth extractions. One calibrated examiner performed measurements of mesiodistal tooth width and mandibular arch perimeter using a digital caliper (Mitutoyo) accurate to 0.01 mm, twice. Bone and tooth discrepancy minimum and maximum values, as well as medians, means and standard deviations, were calculated from pre- and post-treatment casts. Measurements reproducibility was assessed using paired student’s-t test (α = 0.05). No statistical differences were found between first and second measurement, indicating good reproducibility. In at least 60% of cases bone and tooth discrepancy was reduced to clinically suitable values. In the pre-treatment phase, 50% of the sample had lack of space in the mandibular dental arch (median: -0.54 mm). The average discrepancy was also negative (mean -0.16 mm ± 3.36). In the post-treatment phase, median (0.63 mm) and mean (0.65 mm ± 0.85) values were positive and closer, pointing out an acceptable space gain in most dental arches. It may be concluded that orthodontic treatment improved space conditions in the mandibular dental arches, by decreasing negative and positive discrepancies of up to 4 mm and 9 mm, respectively, without the need for extractions.

Effects of masticatory hypofunction on mandibular morphology, mineral density and basal bone area

AIM: This experimental study investigated the association between masticatory hypofunction and mandibular morphological dimensions and internal bone characteristics. METHODS: Twentyfour 21-day-old male Wistar rats were randomly divided into two groups, according to the diet consistency. The control group (CG) was fed a solid diet (pellets) and the experimental group (EG) received a powdered diet during 50 days. All animals were euthanized and their mandibles removed and processed for histomorphometric analysis. A calibrated examiner performed linear and angular measurements (mandibular body length and height, mandibular lengths, ramus depth and height, mandibular base depth, mandibular head and gonial angle) on photographs, estimated bone density in the mandibular ramus region on digital radiographs and assessed the area of cortical and trabecular bone tissue in the second molar region, in 5-µm-thick serial cuts stained with Cason's Trichrome. Measurements for the study groups were compared using Mann-Whitney test (α=0.05). larvae to induce experimental candidiasis, and after 24 hours, the survival rate was assessed. RESULTS: some of the macroscopic dimensions evaluated on photographs were significantly smaller in EG compared to CG, specifically mandibular ramus height (10.77 mm vs. 11.11 mm, p=0.0375), mandibular body length (21.67 mm vs. 22.36 mm, p=0.0165) and height (4.24 mm vs. 4.54 mm, p=0.0016), as well as mandibular base depth (1.24 mm vs. 1.47 mm, p=0.0325). The relative mineral bone density was significantly decreased in EG (1.04) compared to CG (1.25), p<0.001. Rats in the EG also presented smaller trabecular and cortical bone area (2.36 mm²) than those in CG (3.16 mm²), p<0.001. CONCLUSIONS: Based on the above-mentioned measurements, it may be concluded that masticatory hypofunction induced by a powdered diet affected mandibular morphology and was associated with significantly reduced bone content.

Halogen light versus LED for bracket bonding: shear bond strength.

INTRODUCTION: LED light-curing devices seek to provide a cold light activator which allows protocols of material polymerization with shorter duration. OBJECTIVE: The present study aimed to evaluate the shear bond strength of bracket bonding using three types of light-curing devices: One with halogen light (Optilight Plus - Gnatus) and two with LEDs (Optilight CL - Gnatus and Elipar Freelight - 3M/ESPE). RESULTS: Comparing the results by analysis of variance, the Gnatus LED device showed an inferior statistical behavior in relation to other light sources, when activated by a short time. But, when it was used for 40 seconds, the polymerization results were consistent with the other evaluated sources. The device with the best average performance was the halogen light, followed by the 3M/ESPE LED. CONCLUSION: It was concluded that the LEDs may be indicated in orthodontic practice, as long as a protocol is used for the application of light with the activation time of 40 seconds.

Halogen light versus LED for bracket bonding: shear bond strength

INTRODUCTION: LED light-curing devices seek to provide a cold light activator which allows protocols of material polymerization with shorter duration. OBJECTIVE: The present study aimed to evaluate the shear bond strength of bracket bonding using three types of light-curing devices: One with halogen light (Optilight Plus - Gnatus) and two with LEDs (Optilight CL - Gnatus and Elipar Freelight - 3M/ESPE). RESULTS: Comparing the results by analysis of variance, the Gnatus LED device showed an inferior statistical behavior in relation to other light sources, when activated by a short time. But, when it was used for 40 seconds, the polymerization results were consistent with the other evaluated sources. The device with the best average performance was the halogen light, followed by the 3M/ESPE LED. CONCLUSION: It was concluded that the LEDs may be indicated in orthodontic practice, as long as a protocol is used for the application of light with the activation time of 40 seconds.

INTRODUÇÃO: os aparelhos de fotopolimerização por LED buscam proporcionar uma luz ativadora fria, que possibilite protocolos de polimerização do material com menor tempo de duração. OBJETIVO: avaliar a resistência à tração da colagem de braquetes, utilizando três tipos de aparelhos fotoativadores: um de luz halógena (Optilight Plus - Gnatus) e outros dois de LED (Optilight CL - Gnatus; e Elipar Freelight - 3M/Espe). RESULTADOS: comparando os resultados por meio da análise de variância, o aparelho de LED Gnatus apresentou comportamento estatístico inferior em relação às outras fontes de luz, quando ativado por tempo reduzido. Já quando foi utilizado o tempo de 40 segundos, os resultados de polimerização foram compatíveis com as demais fontes avaliadas. O aparelho que apresentou melhor desempenho médio foi o de luz halógena, seguido pelo LED 3M/Espe. CONCLUSÃO: concluiu-se que os LEDs podem ser indicados na prática ortodôntica, uma vez que seja utilizado um protocolo de aplicação da luz com tempo de ativação de 40 segundos.

Análise da relação carga/deflexão de fios ortodônticos retangulares de beta-titânio e aço inoxidável / Analysis of load/deflection rate of rectangular beta-titanium and stainless steel archwires

Visando comparar a relação carga/deflexão de fios ortodônticos retangulares de beta-titânio e aço inoxidável, de diferentes marcas, foram selecionados cinco arcos pré-contornados de cada uma das ligas das seguintes marcas: Abzil Lancer, Morelli, 3M Unitek e Ormco. A metodologia consistiu em posicionar os fios em um manequim ortodôntico com aparelho fixo colado e desprovido de incisivo central superior direito. O conjunto foi fixado a uma máquina universal de ensaios, Emic 10000, munida de uma ponteira de aço que transmitia cargas no centro do segmento do fio selecionado, correspondente ao incisivo extraído. Conforme o equipamento aplicava as forças, um software mensurava a deflexão do fio e gerava, automaticamente, gráficos e tabelas da relação carga/deflexão. Os fios de beta-titânio que apresentaram a menor relação carga/deflexão foram da marca Ormco, seguidos pela 3M Unitek e Abzil Lancer, que não apresentaram diferenças estatisticamente significantes. Analisando comparativamente os dois tipos de fios, notou-se que a liga de beta-titânio demonstrou uma relação carga/deflexão bem menor que a do aço inoxidável, independente da marca comercial do fio.

Comparing the load/deflection rate of beta-titanium and stainless steel rectangular orthodontic wire from different companies makers available in Brazil, they were selected by five archwires from each alloys of: Abzil Lancer, Morelli, 3M Unitek and Ormco. The methodology of replace the archwires in an orthodontic mannequin with fixed appliance and without right central incisor superior. The team was fixed in a Universal Testing Machine - Emic 10000 - that has a stainless pointer which takes the load in the center of the selected section of wire, in the area of the extracted incisor. While the equipment pressing the wire, a software was measuring the deflection of the wire and providing graphics and charts of load/deflection relate. The arches of beta-titanium alloy that had the lowest load/deflection rate was Ormco followed by 3M Unitek and Abzil Lancer, those didn't show significant statistic differences. Comparing both types of wires, concluded that the beta-titanium alloy showed a lower load/deflection rate than stainless steel, independent of brand wires.

Calibração das molas do aparelho pendulum/pendex: sugestão de padronização e ativação / Calibration of pendulum/pendex springs: suggestion of standardisation and activation

O conhecimento da magnitude da força e do sistema deforça produzidos pelo distalizador intrabucal é de fundamental importância parao controle dentário durante a distalização dos molaressuperiores.Sendo assim, esta pesquisa objetivou o desenvolvimentode uma padronização do desenho e da ativação das molas do aparelhopendulum e a avaliação da força liberada. Com este propósito, foramdesenvolvidos 12 corpos de prova quadrangulares de resina acrílicade dimensão padronizada em 20,0 mm por 20,0 mm, contendo asmolas distalizadoras construídas com fio de titânio-molibdênio .032",da marca Ormco (Funak Ormco Ltda., São Paulo, Brasil), caracterizadapela conformação básica de helicoide, de diâmetro interno de 4,0 mm,alça horizontal de ajuste de 4,0 mm de largura por 4,0 mm de altura.As molas foram ativadas até que ficassem perpendiculares ao centrodobotãode resina e foram testadas in vitro em uma balança dínamométricasimplesdesenvolvida para quantificar a magnitude da forçageradapor tal ativação. Os dados coletados foram submetidos ao testede normalidadede Kolmogorov-Smirnov e ao teste t independente emnivel de significância de 5%. Concluiu-se que o desenho e a ativaçãoda mola do aparelho pendulum propostos neste trabalho podem serutilizados como padrão para se alcançar a força necessária para adistalização dos molares superiores. A força distalizadora resultantevarioude valor mínimo de 212 g e máximo de 272 g, com magnitudemédia de 253,3 g e molas com comportamento semelhante em 75%da amostra.

Knowledge of force magnitude and force system producedby the intraoral distalizer is of utmost importance for dental controlduring maxillary molars distalization. Therefore, this research aimed thedevelopment of a standardization of the design and activation of thesprings of the pendulum appliance, and evaluation of the force applied.With this purpose, 12 squared proof bodies made of acrylic resin weredeveloped, with standardized dimension of 20.0 mm by 20.0 mm, containingthe distalizer springs built of titanium-molybdenum wire .032",Ormco brand (Funak Ormco Ltda., São Paulo, Brezil), characterized bythe basic helicoid shape with internal diameter of 4.0 mm, horizontaladjustment loop of 4.0 mm wide by 4.0 mm high. The springs wereactivated until they were perpendicular to the center of the resin button,and they were tested in vitro on a simple dynamometric scale developedto quantify the force magnitude generated by such activation. Thedata collected were submitted to the kolmogorov-smirnov normalitytest and to the independent test in a levei of significance of 5%. Itwas concluded that the design and the activation of the spring of thependulum appliance present in this study can be used as a standard toreach the necessary force for the maxillary molars distalization. Theresulting distalizer force varied from a minimum value of 212 g to amaximum of 272 g, with medium magnitude of 253.3 g, and that thesprings had a similar behavior in 75% of the sample.

Análise da forma do arco dentário e da distância intercaninos em más-oclusões de classe I / Assessment of arch form and intercanine width in class I malocclusions

Há um interesse clínico justificável pela avaliação do formato de arco mais favorávelà estabilidade pós-correção ortodôntica. Assim, o objetivo deste estudo foi compararas formas dos arcos dentários e as distâncias intercaninos maxilar e mandibular antes eapós o tratamento, em más-oclusões de Classe I. A amostra incluiu 28 pares de modelosde estudo pré e pós-tratamento de pacientes dos 11 anos e sete meses aos 24 anos eum mês de idade no início do tratamento e dos 13 anos e 11 meses aos 25 anos e setemeses ao final (22 do gênero feminino, seis do masculino). Um examinador calibrado avaliouas formas dos arcos com gabaritos Ortho Form e mensurou as distâncias intercaninospor meio de paquímetro digital (precisão de 0,01 mm). A análise das coincidências entreformatos dos arcos foi realizada pela estatística Kappa. As distâncias intercaninos foramcomparadas pelo teste t Student (a = 5%). O formato ovoide foi o mais frequente pré e póstratamento,apesar dos coeficientes Kappa terem indicado 30% e 14,5% de coincidência paraos arcos maxilar e mandibular, respectivamente. As distâncias intercaninos maxilares pré(34,66 mm ± 2,7 mm) e pós-tratamento (34,76 mm ± 2,0 mm) não diferiram estatisticamente.Também não houve diferenças significativas entre as distâncias intercaninos mandibularespré (26,98 mm ± 2,0 rnrn) e pós-tratamento (26,40 mm ± 1,7 rnrn). Nos casos tratados demás-oclusões de Classe I, o formato ovoide foi o mais prevalente em ambos os arcos e asdistâncias intercaninos não foram significativamente alteradas.

There is a justifiable clinical interest in the assessment of the most favorablearch form related to post-treatment stability in Orthodontics. Thus, the aim of this study wasto compare pre- and post-treatment maxillary and mandibular arch forms and intercaninewidths, in Class I malocclusions. The sample consisted of 28 pre- and post-treatment pairsof study casts taken from patients aged 11 years and 7 months to 24 years and 1 month atthe beginning of treatment and from 13 years and 11 months to 25 years and 7 months atthe end (22 females, 6 males). One calibrated examiner assessed arch forms using the OrthoForm templates and measured intercanine widths by means of a digital caliper (accurate to0.01 mm). Analysis of coincidence between arch forms was carried out using Kappa statistics.Intercanine widths were compared using the student's t-test (a = 5%). Ovoid was themost frequent pre- and post-treatment arch form, although kappa coefficients have indicated30% e 14.5% of coincidence for the maxillary and mandibular arches, respectively. Pre-(34.66 mm ± 2.7 mm) and post-treatment (34.76 mm ± 2. Omm) maxillary intercanine widthswere not statistically different. Similarly, no significant differences were found between pré(26.98 mm ± 2.0 mm) and post-treatment (26.40 mm ± 1.7 mm) mandibular intercaninewidths. After treatment of these Class I malocclusions, the ovoid shape was the most prevalentone in both dental arches and the intercanine widths were not significantly modified.

Are torque values of preadjusted brackets precise?

OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º) presented statistically significant difference from the proposed values (-7º). For the mandibular canines, American Orthodontics (-6.34º) and Ortho Organizers (-6.25º) presented statistically significant differences from the standards (-6º). Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment.

Are torque values of preadjusted brackets precise?

OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º) presented statistically significant difference from the proposed values (-7º). For the mandibular canines, American Orthodontics (-6.34º) and Ortho Organizers (-6.25º) presented statistically significant differences from the standards (-6º). Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment.