Does the composite attachment of clear aligners compromise the effectiveness of dental bleaching? An in vitro study.

INTRODUCTION: This study aimed to evaluate the effectiveness of dental bleaching with hydrogen peroxide 35% on the surface below the attachments. METHODS: Twenty-four blocks of bovine incisors were equally divided into 2 groups. The control group comprises the enamel surface free of attachments, whereas the attachment group comprises the enamel surface with attachment. Initial staining of samples was performed with black tea for 7 days; then, an attachment was made in the attachment group with Z250 resin and new staining for another 7 days in all samples. After staining, in-office bleaching was performed in both groups, and the attachments from the attachment group were removed. Color reading was performed with a spectrophotometer at all stages: initial (baseline), after 7 days of staining, after 14 days of staining, after immediate bleaching, and after 24 hours of bleaching. The color difference was calculated, and data analysis was performed using the t test for intergroup analysis. RESULTS: The results showed effective bleaching in both groups; however, there was a statistically significant difference in color change between them 24 hours after bleaching. CONCLUSION: It was concluded that the presence of attachment did not impair the action of the bleaching agent on the tooth surface.

Laser-photobiomodulation on titanium implant bone healing in rat model: comparison between 660- and 808-nm wavelength.

Laser-photobiomodulation (L-PBM) has been widely studied and its biomodulatory effects have been established on irradiated cells, increasing viability and proliferation and on damaged tissues. In addition, L-PBM may reduce and modulate the inflammatory process. The effect of 660-nm and 808-nm laser-photobiomodulation on bone repair around titanium dental implants placed in rat's femur was evaluated by histomorphometry. Twenty-seven Wistar rats were divided into 3 groups of nine animals: group C - non-irradiated control; group R - λ=660nm irradiated; and group IR - λ=808nm irradiated. Each group was further divided in 3 subgroups of three animals each, according to histomorphometry analysis in 3 days, 7 days, and 14 days after irradiation. Histological H.E.-stained slides were photographed, and bone matrix measured in new-formed bone area. Bone matrix histomorphometry analysis indicates that at 7 days in the irradiated groups (R and IR), a bigger area matrix was observed in relation to control group (C) (p=0.04 and p=0.048 respectively). On the other hand, at 14 days, control group (C) presented a bigger area than infrared irradiated (IR) (p=0.001) and red irradiated group (R) also showed a bigger area than infrared irradiated group (IR) (p=0.019). Histological analysis indicates that irradiated groups (R and IR) exhibited a faster bone tissue matrix production than control group.

Predictors of orthodontic treatment conclusion: A historical cohort study.

INTRODUCTION: The study investigated which patient and orthodontic treatment factors act as predictors for the conclusion of the ongoing treatment in a dental clinic of a specialization program in Orthodontics. METHODS: Data were collected from the records of patients treated from 1997 to 2015. Potential predictors for treatment conclusion were investigated: patient-related factors (PRFs) and treatment-related factors (TRFs). PRFs were sex, age, face balance, Angle malocclusion classification, open bite, denture, facial pattern, facial profile, buccal corridor, crossbite, maxillary deficiency, and sagittal mandibular behavior; and TRFs were therapeutic approaches, treatment modality, extractions, and Bolton discrepancy. The initial and final treatment dates were collected. Descriptive data analysis, univariate, and multivariate logistic regression were performed (5% significance). RESULTS: Of the 903 records, 561 patients were included in the study. It was demonstrated that starting the treatment at a young age (PRF) and the presence of crossbite (TRF) are predictive factors for the treatment conclusion. A vertical facial pattern (dolichofacial or brachyfacial) and a greater number of extractions for orthodontic reasons may contribute positively to the conclusion of the treatment. The frequency of treatment inconclusion was higher during the first 2 years of treatment (more than 50% of the patients that initiated the treatment). CONCLUSIONS: Young age at the beginning of treatment and the presence of crossbite malocclusion can increase the chance of treatment conclusion.

An in vitro assessment of the influences of different wire materials and bracket systems when correcting dental crowding.

A recently developed orthodontic wire alloy known as GUMMETAL® is claimed to deliver more physiological forces to correct dental mispositioning. However, its mechanical characteristics have not been fully characterized yet. This study aimed to determine and compare the elastic properties of different wire alloys, such as nickel-titanium (NiTi), stainless steel (SS), and GUMMETAL®, and assess their unloading forces when combined with either conventional or self-ligating brackets (CL and SL) when correcting dental crowding. All wires had a 0.016″ cross-section diameter. A three-point bending test was performed to assess the maximum deflection of each wire. Then, a subsequent analysis measured the unloading force for each wire/bracket system in a dental crowding clinical simulation device. The test was carried out in a universal testing machine with a cross-speed displacement of 0.5 mm/min. Data were recorded in different ranges and statistically evaluated using two-way analysis of variance. GUMMETAL® displayed higher unloading mean forces in SL brackets (2228.78 cN) than CL brackets (1967.38 cN) for the 1.6-3.0 deflection interval (p = 0.018). Within this interval, NiTi showed higher forces when used with CL brackets (2683.06 cN) than with SL brackets (1179.66 cN) (p < 0.0001). For the CL bracket systems, SS wires showed higher forces (2125.31 cN) in the 1.0-1.6 deflection interval than the other two wire alloys (NiTi, 1541.52 cN and GUMMETAL®, 852.65 cN) (p < 0.0001). SS wires also displayed lower forces with SL brackets (1844.01 cN) than in CL brackets (2125.31 cN) (p = 0.049). Thus, only GUMMETAL® revealed to be an optimal choice for SL brackets, whereas NiTi for CL brackets.

Miniscrew insertion sites of infrazygomatic crest and mandibular buccal shelf in different vertical craniofacial patterns: A cone-beam computed tomography study.

OBJECTIVE: To identify optimal areas for the insertion of extra-alveolar miniscrews into the infrazygomatic crest (IZC) and mandibular buccal shelf (MBS), using cone beam computed tomography (CBCT) imaging in patients with different craniofacial patterns. METHODS: CBCT reconstructions of untreated individuals were used to evaluate the IZC and MBS areas. The participants were divided into three groups, based on the craniofacial pattern, namely, brachyfacial (n = 15; mean age, 23.3 years), mesofacial (n = 15; mean age, 19.24 years), and dolichofacial (n = 15; mean age, 17.79 years). In the IZC, the evaluated areas were at 11, 13, and 15 mm above the buccal cusp tips of the right and left first molars. In the MBS, the evaluated areas were at the projections of the first molars' distal roots and second molars' mesial and distal roots, at a 4- and 8-mm distance from the cementoenamel junction. Intergroup comparisons were performed with analysis of variance and the Tukey test. RESULTS: There was no statistically significant difference in the IZC bone thickness among the groups. For MBS bone availability, some comparisons revealed no difference; meanwhile, other comparisons revealed increased MBS bone thickness in the brachyfacial (first molars distal roots) and dolichofacial (second molars mesial and distal roots) patterns. CONCLUSIONS: There was no significant difference in the IZC bone thickness among the groups. The facial skeletal pattern may affect the availability of ideal bone thickness for the insertion of extra-alveolar miniscrews in the MBS region; however, this variability is unlikely to be clinically meaningful.

Treatment of maxillary canine transposition.

Transposition of maxillary teeth is an eruptive disturbance occurring in approximately 1 of every 300 orthodontic patients. Such cases are frequently very challenging in terms of treatment planning and orthodontic management. The canine is one of the most commonly transposed teeth, ectopically positioned with either the lateral incisor or the first premolar. This case report illustrates unique orthodontic treatment, describes treatment procedures, and presents the final outcome of bilateral maxillary canine-lateral incisor complete transpositions in which the involved teeth were moved to their clinically normal position in the dental arch without extracting premolars.

Proteoglycans and dental biology: the first review.

Proteoglycans (PGs) are proteins which are vital components located in the extracellular matrix, cell surface or intracellular granules. They are linked to polysaccharides called glycosaminoglycans. There are several aspects associated with PGs, such as cell signaling and organization of the extracellular matrix (ECM), making them pivotal participants in many tissue compositions. In teeth, PGs also play an essential role, as many of its components have elaborate ECM structures. However, lack of information on how PGs constitute the various tissues of the tooth and on their roles makes it difficult to elicit the major importance associated with this class of proteins. This review seeks to detail how proteoglycans are involved in many aspects of tooth organization and development, and as far as we are concerned, this has not been performed yet. We have also exemplified the participation of small leucine-rich proteoglycans, a special class of PGs seen in dental trauma cases.

Comparison of deflection forces of esthetic archwires combined with ceramic brackets.

Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Methods Non-coated NiTi (NC), rhodium coated NiTi (RC), teflon coated NiTi (TC), epoxy coated NiTi (EC), fiber-reinforced polymer (FRP), and the three different conventional brackets metal-insert polycrystalline ceramic (MI-PC), polycrystalline ceramic (PC) and monocrystalline ceramic (MC) were used. The specimens were set up on a clinical simulation device and evaluated in a Universal Testing Machine (Instron). An acrylic device, representative of the right maxillary central incisor was buccolingually activated and the unloading forces generated were recorded at 3, 2, 1 and 0.5 mm. The speed of the testing machine was 2 mm/min. ANOVA and Tukey tests were used to compare the different archwires and brackets. Results The brackets presented the following decreasing force ranking: monocrystalline, polycrystalline and polycrystalline metal-insert. The decreasing force ranking of the archwires was: rhodium coated NiTi (RC), non-coated NiTi (NC), teflon coated NiTi (TC), epoxy coated NiTi (EC) and fiber-reinforced polymer (FRP). At 3 mm of unloading the FRP archwire had a plastic deformation and produced an extremely low force in 2; 1 and 0.5 mm of unloading. Conclusion Combinations of the evaluated archwires and brackets will produce a force ranking proportional to the combination of their individual force rankings.

Force level of small diameter nickel-titanium orthodontic wires ligated with different methods.

BACKGROUND: The aim of this study was to compare the deflection force in conventional and thermally activated nickel-titanium (NiTi) wires in passive (Damon Q) and active (Bioquick) self-ligating brackets (SLB) and in conventional brackets (CB) tied by two different methods: elastomeric ligature (EL) and metal ligature (ML). METHODS: Two wire diameters (0.014 and 0.016 in.) and 10 specimens per group were used. The specimens were assembled in a clinical simulation device and tested in an Instron Universal Testing Machine, with a load cell of 10 N. For the testing procedures, the acrylic block representative of the right maxillary central incisor was palatally moved, with readings of the force at 0.5, 1, 2, and 3 mm, at a constant speed of 2 mm/min and temperature of 36.5 °C. RESULTS: The conventional NiTi released higher forces than the thermally activated NiTi archwires in large deflections. In general, the SLB showed lower forces, while the ML had higher forces, with both showing a similar force release behavior, constantly decreasing as the deflection decreased. The EL showed an irregular behavior. The active SLB showed smaller forces than passive, in large deflections. CONCLUSIONS: The SLB and the ML exhibit standard force patterns during unloading, while the elastomeric ligatures exhibit a randomly distributed force release behavior.

Reference standard thickness for bone plates of upper teeth: an ultra-high-resolution study using tomographic mapping / Padrão de referência de espessura para cristas ósseas de dentes superiores: um estudo de ultra-alta resolução usando mapeamento tomográfico

Objective: it is important to know the thicknesses of the alveolar bone plates (ABPs) based on the current literature for the planning and success of orthodontic treatment. However, studies have scientific limitations regarding ABPs as the image resolution is not adequate and is restricted to a few teeth or buccal face only. This study was aimed at reporting a reference standard for bone plates of upper teeth, in which 15 patients (mean age of 21.79 years) with balanced occlusion and a harmonious facial profile were evaluated using cone-beam computed tomography at a voxel size of 0.1 mm. Material and Methods: bone tissues of the cervical, middle, and apical thirds of the root (buccal and palatal), the distance between cement-enamel junction (CEJ) and alveolar bone crest (ABC), and inclination of the teeth to the palatal plane were evaluated. Paired t-test, Spearman's correlation tests, and linear regression tests were used (P < 0.05). Results: the buccal distance between the CEJ and ABC was greater than the palatal one in all pairs of teeth. Most of the bone tissues had a thickness ≤ 1 mm in the buccal face, whereas in the cervical-apical direction, the thickness was ≥ 2 mm. There is no equivalence between genders in the sample. Conclusion: the reduced buccal bone architecture around the first premolars was indicative of local gingival recessions, and the lack of gender uniformity was suggestive of individual evaluation. References of normal bone tissue determining the orthodontic limits were provided to assist in the treatment planning. (AU)

Objetivo: é importante conhecer as espessuras das cristas ósseas alveolares (COAs) com base na literatura atual para o planejamento e sucesso do tratamento ortodôntico. No entanto, os estudos apresentam limitações científicas em relação às COAs, pois a resolução da imagem não é adequada e está restrita apenas a alguns dentes ou face vestibular. Este estudo teve como objetivo descrever um padrão de referência para corticais ósseas de dentes superiores, no qual 15 pacientes (idade média de 21,79 anos) com oclusão equilibrada e perfil facial harmonioso foram avaliados por meio de tomografia computadorizada de feixe cônico no tamanho de voxel de 0,1 mm. Material e Métodos: os tecidos ósseos dos terços cervical, médio e apical da raiz (vestibular e palatina), a distância entre a junção cemento-esmalte (JCE) e a crista óssea alveolar (COA) e a inclinação dos dentes ao plano palatino foram avaliados. Foram utilizados o teste t pareado, os testes de correlação de Spearman e os testes de regressão linear (P < 0,05). Resultados: a distância vestibular entre a JEC e a COA foi maior que a palatina em todos os pares de dentes. A maioria dos tecidos ósseos apresentou espessura ≤ 1 mm na face vestibular, enquanto no sentido cérvico-apical a espessura foi ≥ 2 mm. Não há equivalência entre os gêneros na amostra. Conclusão: a arquitetura óssea vestibular reduzida ao redor dos primeiros pré-molares foi indicativa de recessões gengivais locais, e a falta de uniformidade de gênero foi sugestiva de avaliação individual. Referências de tecido ósseo normal determinando os limites ortodônticos foram fornecidas para auxiliar no planejamento do tratamento. (AU)

External root resorption with the self-ligating Damon system-a retrospective study.

BACKGROUND: The aim of this study was to compare the degree of external apical root resorption (EARR) in patients treated with self-ligating Damon appliances and with conventional preadjusted appliances. METHODS: The sample comprised 52 patients, divided into two groups. Group 1 consisted of 25 patients treated with self-ligating Damon appliances, with an initial age of 16.04 years, final age of 18.06 years, and treatment time of 2.02 years. Group 2 consisted of 27 patients, treated with conventional preadjusted appliances, with an initial age of 16.77 years, final age of 18.47 years and treatment time of 1.70 years. The groups were matched regarding the initial and final ages, treatment time, type of malocclusion, and treatment protocol without extractions. Root resorption was evaluated on periapical radiographs of the maxillary and mandibular incisors at the end of orthodontic treatment with the scores of Levander and Malmgren. Intergroup comparisons of root resorption were performed with Mann-Whitney tests. RESULTS: No significant difference in the degree of root resorption between the two groups was found. CONCLUSIONS: Similar degrees of resorption can be expected after non-extraction treatment with Damon self-ligating or conventional preadjusted appliances.

Análisis de flexión en alambres de níquel-titanio con y sin propiedades de transformación térmica / Bending analysis of nickel-titanium wires with and no thermal transformation properties

Objetivo: Evaluar el comportamiento de los alambres de aleación de níquel-titanio con y sin propiedades de transformación térmica en la relación carga/deflexión. Materiales y método: Para ello, 30 segmentos de alambres de níquel-titanio con calibre .014" y 30 mm de largo fueron cortados, conformando 10 segmentos de alambre Flexy NiTi de Orthometric®, 10 segmentos Flexy Copper NiTi termoactivado y 10 segmentos CuNiTi de OrmcoTM. Se usó una máquina universal de ensayos Instron® para analizar el comportamiento de carga y deflexión de los segmentos en una prueba de tres puntos, registrando las fuerzas alcanzadas en 0,5 mm: 1 mm, 2 mm y 4 mm de deflexión. Resultados: Hubo una diferencia estadísticamente significativa entre todos los alambres y entre todas las deflexiones, ya que el alambre Flexy Cooper NiTi presentó la menor carga entre todas las deflexiones analizadas. Conclusión: Se concluye que los alambres termoactivados alcanzan fuerzas más leves, lo que los hace más apropiados para alineaciones iniciales, las cuales requieren un mayor rango de deflexión(AU)

Comparison of deflection forces of esthetic archwires combined with ceramic brackets

Abstract Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Methods Non-coated NiTi (NC), rhodium coated NiTi (RC), teflon coated NiTi (TC), epoxy coated NiTi (EC), fiber-reinforced polymer (FRP), and the three different conventional brackets metal-insert polycrystalline ceramic (MI-PC), polycrystalline ceramic (PC) and monocrystalline ceramic (MC) were used. The specimens were set up on a clinical simulation device and evaluated in a Universal Testing Machine (Instron). An acrylic device, representative of the right maxillary central incisor was buccolingually activated and the unloading forces generated were recorded at 3, 2, 1 and 0.5 mm. The speed of the testing machine was 2 mm/min. ANOVA and Tukey tests were used to compare the different archwires and brackets. Results The brackets presented the following decreasing force ranking: monocrystalline, polycrystalline and polycrystalline metal-insert. The decreasing force ranking of the archwires was: rhodium coated NiTi (RC), non-coated NiTi (NC), teflon coated NiTi (TC), epoxy coated NiTi (EC) and fiber-reinforced polymer (FRP). At 3 mm of unloading the FRP archwire had a plastic deformation and produced an extremely low force in 2; 1 and 0.5 mm of unloading. Conclusion Combinations of the evaluated archwires and brackets will produce a force ranking proportional to the combination of their individual force rankings.

Evaluation of the emergency procedure in cases of dental avulsion among different professionals in the city of São José dos Campos-SP / Avaliação da conduta emergencial frente a casos de avulsão dental entre diferentes profissionais relacionados a este tipo de evento na cidade de São José dos Campos-SP

Objective: To assess the knowledge of the immediate action to be taken in cases of tooth extraction among professionals from different areas who witness this type of trauma in the city of São José dos Campos - SP, as well as guide them to the conduct immediately to be taken, since the prognosis of avulsed teeth element is directly related to the time it takes to replanted in respective alveolus. Besides the time factor, other factors such as management of the tooth, storage environment, treatment of the replanted tooth and preservation technique also have influence on the best prognosis. Material & Methods: For the development of the survey 50 professionals were randomly selected from the following professions: firefighters, doctors, nurses, teachers and dentists in different workplaces and from both genders. An evaluation was made through a questionnaire related to emergency treatment in cases of dental avulsion. The same was applied to all professionals, and questions were answered in the same period of time. Results: All data obtained was evaluated and a statistical analysis was performed. The professionals interviewed had low knowledge about the emergency procedure to be performed in cases of tooth avulsion Conclusion: Considering that part of the dentists are unaware of the appropriate techniques for this procedure, it was concluded that there is a great need for scientific and technical knowledge by this professional which would result in better patient care and more clarification on the subject the population.

Introdução: Analisar o conhecimento sobre a conduta imediata a ser tomada em casos de avulsão dental entre os profissionais de diferentes áreas que presenciam este tipo de trauma na cidade de São José dos Campos– SP, bem como orientá-los quanto à conduta imediata a ser tomada, uma vez que o prognóstico do elemento dental avulsionado está diretamente relacionado com o tempo que se leva para reimplantá-lo em seu respectivo alvéolo. Além deste, outros fatores como manejo, meio de armazenamento, tratamento do dente reimplantado, técnica de reimplante e preservação também influenciam no melhor prognóstico. Material e Métodos: Foram selecionados de forma aleatória 50 profissionais de cada uma das seguintes áreas: bombeiros, médicos, enfermeiros, professores e cirurgiões-dentistas, em diferentes locais de trabalho e de ambos os gêneros. Foi realizada uma avaliação através de um questionário relacionado ao tratamento emergencial em casos de avulsão dental. O mesmo foi aplicado para todos os profissionais e as perguntas foram respondidas no mesmo período de tempo. Resultados: Todos os dados obtidos foram avaliados e uma análise estatística foi realizada. Os profissionais entrevistados apresentaram baixo conhecimento sobre o procedimento de emergência que deve ser realizado nos casos de avulsão dental. Conclusão: Visto até mesmo que parte dos cirurgiões-dentistas desconhecem as técnicas adequadas para tal procedimento, concluiu-se que existe uma grande necessidade de conhecimento técnico e científico por parte deste profissional, o que resultaria em um melhor atendimento ao paciente e um maior esclarecimento sobre o tema à população.

Opções de tratamento ortodôntico compensatório da classe III sem exodontias de premolares / Treatment options of compensatory orthodontic treatment without premolar extractions

O tratamento ortodôntico, em pacientes adultos com padrão esquelético apresentando pequena discrepância, pode ser realizado com a camuflagem ortodôntica, por meio das compensações dentárias. Essas compensações, muitas vezes, são consideradas como fatores de risco para a saúde periodontal, principalmente, quando associadas à movimentos de inclinação dos incisivos, tanto para lingual como para vestibular. A finalidade do presente artigo foi apresentar, através de dois de casos clínicos, duas opções diferentes de tratamento compensatório para a Classe III. A primeira com o emprego de bráquetes autoligáveis do Sistema Damon, com prescrição individualizada para os arcos dentários superior e inferior, além dos elásticos intermaxilares de Classe III. Essa modalidade tem sua indicação na correção dos problemas dentários com suave discrepância esquelética entre as bases ósseas, corrigindo os problemas oclusais sem grandes sequelas para os dentes e tecidos de suporte, devido ao torque diferenciado dos bráquetes. A segunda opção é a movimentação sagital dos dentes inferiores para distal por meio de ancoragem esquelética com miniplacas de titânio. Esses dispositivos de ancoragem temporária (DATs) oferecem uma estável e efetiva ancoragem para a movimentação ortodôntica no tratamento da Classe III.(AU)

Orthodontic treatment, in adult patients with a skeletal pattern presenting a small discrepancy, can be performed with orthodontic camouflage by dental compensations. These compensations are many times considered as risk factors for periodontal health, especially when associated with incisor inclination, both lingual and buccal. The aim of this paper was to present, through two clinical cases, two different options for compensatory Class III treatment. The first one with the use of self-ligating brackets (Damon System), with individualized prescriptions for upper and lower dental arches, in addition to Class III intermaxillary elastics. This modality has its indication in the correction of dental problems with mild skeletal discrepancy between bone bases, correcting the occlusal problems without major sequelae for teeth and supporting tissues, due to brackets different torque. The second option is retracting the whole lower dentition through skeletal anchorage with titanium miniplates. These temporary anchoring devices (TADs) provide a stable and effective anchorage for orthodontic movement in Class III treatment.(AU)

Bráquetes autoligáveis / Self-ligating brackets

Os bráquetes autoligáveis tornaram-se populares recentemente no mercado ortodôntico com diversos atrativos, incluindo um modo de ligação mais rápida, menor atrito, menor dor e maior conforto ao paciente, menor número de atendimentos e menor tempo de cadeira. Embora diversos tipos de bráquetes autoligáveis tenham estado disponíveis por diversos anos, só recentemente cresceram novamente em popularidade. O objetivo deste trabalho é revisar a literatura sobre o assunto, elucidando as vantagens da utilização desses bráquetes, os efeitos dos mesmos sobre a forma do arco, inclinação dos incisivos e as diferenças com relação aos torques.

Self-ligating brackets have become popular recently in the orthodontic market with many attractions including a faster ligation, less friction, less pain and greater patient comfort, fewer appointments and shorter chair time. Although several types of self-ligating brackets have been available for several years, only recently they have grown in popularity again. The objective of this work is to review the literature on the subject, explaining the advantages of using these brackets, their effects on arch form, inclination of incisors and differences related to torques.

Princípios gerais da mecânica com braquetes autoligáveis / General guidelines of self-ligating brackets

O presente trabalho tem a finalidade de apresentar, de forma simples e objetiva, alguns princípios gerais que norteiam a mecânica com aparelhos autoligáveis na clínica diária. Serão discutidos tópicos clínicos relevantes, como as características ideais dos braquetes autoligáves, sua eficiência clínica, conforto e tempo de tratamento, bem como o emprego de suas diferentes prescrições, o posicionamento dos acessórios e mecânica peculiar (uso de elásticos no início do tratamento, desarticulação, sequência e troca dos fios de nivelamento, emprego de cadeias elastoméricas sob o fio, uso de stops e molas abertas, além de desgastes interproximais). Dessa forma, o artigo visa apresentar, segundo a visão dos autores, uma orientação clínica para que se obtenha um tratamento de qualidade e com resultados estáveis e eficientes.

Evaluation of Damon system effects in alveolar bone support by cone-beam computed tomography (CBCT) / Avaliação dos efeitos do sistema Damon no suporte ósseo dentário por meio da tomografia computadorizada de feixe cônico (TCFC)

Introduction: The aim of this study was to assess changes in buccal bone thickness, buccolingual inclinations and transversal width of teeth during treatment with the Damon System. Material and Methods: Twenty-one patients of both sexes, with a mean initial age of 14.99 ± 1.27 years, with complete permanent dentition up to second molars, treated with no extractions and minimum initial crowding of 4mm (maxillary: - 6.71mm (SD 2.99), mandibular: -5.12 mm (SD 2.03)) were taken to CBCT scan before (T1) and after (T2) orthodontic treatment with the Damon System. In the maxilla, buccal bone thickness was measured at 4mm and 6mm from the cementoenamel junction of the right first molar in the apical direction. For the mandible, the same protocol was used, but the axial sections were performed at 4mm and 8mm. Buccolingual inclinations were verified using CBCT-panoramic cross-sectionals based on the image that presented the most appropriate view of buccal face of the clinical crown. Transversal width measurements were performed in intermolar, intersecond premolar, interfirst premolar and intercanine distances by 3D multiplanar reconstruction in the two-time periods. Distribution of the variables was verified by Shapiro-Wilk test. Changes in all variables from T1 to T2 were compared using paired t-test. The correlation between changes in bone thickness, buccolingual inclinations and transversal width was assessed by Pearson correlation coefficient. Results: At 4mm height, treatment with Damon System produced a statistically significant decrease in buccal bone thickness, mainly in the posterior teeth of the maxillary and mandibular arches. At 8mm, there was a statistically significant decrease in buccal bone thickness only in mandibular molar and premolar teeth. Regarding buccolingual inclinations, a statistically significant increase was observed in the maxillary arch, mainly in the incisors and premolars teeth. In the mandibular arch, all teeth showed a statistically significant increase of buccal inclination, except for the left canine and first molar. Concerning transversal width, there was a statistically significant increase in maxillary and mandibular transversal width at the end of treatment, exception of the maxillary canines. Conclusion: In general, orthodontic treatment with the Damon self-ligating brackets system showed an expansion of the dental arches followed by a decrease in buccal bone thickness, caused by buccal inclination of dental crowns in both arches.(AU)

Introdução: O objetivo do presente estudo foi avaliar as alterações nas espessuras das tábuas ósseas vestibulares, nas inclinações dentárias e nas dimensões transversais dos arcos durante o tratamento com o Sistema Damon de braquetes autoligáveis. Materiais e Métodos: Vinte e um adolescentes de ambos os gêneros com idade média de 14,99 ± 1,27 anos, dentadura permanente completa até os segundos molares, tratados sem extrações e apinhamento inicial mínimo de 4mm (superior: -6,71mm (DP 2,99), inferior: -5,12mm (DP 2,03) foram submetidos a exames de Tomografia Computadorizada de Feixe Cônico (TCFC) antes (T1) e após (T2) o tratamento ortodôntico com o Sistema Damon. A espessura da tábua óssea vestibular da maxila foi determinada por cortes axiais nas distâncias de 4mm e 6mm localizados apicalmente à junção amelocementária do primeiro molar superior direito. Para a mandíbula, foi realizado o mesmo protocolo, porém os cortes axiais selecionados foram realizados nas distâncias de 4mm e 8mm apicalmente à junção amelocementária do primeiro molar inferior direito. Para mensuração das inclinações dentárias, foram utilizados cortes parassagitais gerados a partir da imagem panorâmica da TCFC. As medidas foram realizadas a partir do ângulo formado pela linha vestibular da coroa clínica (LVCC) e a borda superior ou inferior da imagem selecionada. As dimensões transversais dos arcos (6-6/5-5/4-4/3-3) foram mensuradas por meio de cortes axiais das reconstruções 3D. As variáveis foram submetidas ao teste de Shapiro-Wilk para testar sua distribuição. As alterações de todas as variáveis de T1 para T2 foram comparadas por meio dos testes t-pareado. A correlação entre as alterações das espessuras ósseas com as alterações nas inclinações dentárias e dimensões transversais dos arcos foi verificada pelo coeficiente de correlação de Pearson. Resultados: o tratamento com o Sistema Damon produziu uma diminuição estatisticamente significante na espessura da tábua óssea vestibular predominantemente na região posterior dos arcos superior e inferior no corte realizado a 4mm. Nos cortes realizados a 8mm, houve uma diminuição estatisticamente significante na espessura óssea vestibular somente na região de molares e premolares inferiores. Em relação as inclinações vestibulolinguais dos dentes, um aumento estatisticamente significante foi observado no arco superior, com predomínio nos incisivos e premolares. No arco inferior, todos os dentes mostraram um aumento estatisticamente significante da inclinação para vestibular, com exceção do canino e primeiro molar esquerdos. As dimensões transversais dos arcos superiores e inferiores sofreram um aumento estatisticamente significante ao final do tratamento com o Sistema Damon, com exceção dos caninos superiores. Conclusão: De maneira geral, o tratamento ortodôntico com o Sistema Damon de braquetes autoligáveis produziu um aumento nas dimensões transversais seguida por uma redução da espessura óssea na parede vestibular dos dentes, ocasionada pela inclinação vestibular das coroas dentárias em ambos os arcos.(AU)