RESUMO Introdução: Durante o tratamento ortodôntico, muitos pacientes solicitam, também, alteração na cor dos seus dentes. Objetivo: O presente estudo avaliou diferentes produtos clareadores e branqueadores, quanto à sua eficácia sob os braquetes ortodônticos. Métodos: 70 incisivos bovinos foram aleatoriamente divididos em cinco grupos (n = 14): C) dentifrício não branqueador (controle); WTsi) dentifrício branqueador com sílica hidratada; WThp) dentifrício branqueador com peróxido de hidrogênio a 2%; OB) clareamento no consultório e HB) clareamento caseiro. Usando um espectrofotômetro Easyshade, foram avaliadas duas áreas na superfície vestibular dos dentes: sob o braquete (experimental) e ao redor do braquete (controle). Para análise estatística, foram usados os testest pareado, ANOVA e Tukey. Resultados: As comparações intragrupos demonstraram que, nos grupos C, WThp e HB, ocorreram diferenças estatisticamente significativas nas alterações de cor do esmalte (ΔEab) entre as áreas sob o braquete e ao redor do braquete (C: sob o braquete = 7,97 ± 2,35, ao redor do braquete = 2,86 ± 0,81, p< 0,01; WThp: sob o braquete = 4,69 ± 2,98, ao redor do braquete = 2,05 ± 1,41, p< 0,01; HB: sob o braquete = 7,41 ± 2,89, ao redor do braquete = 9,86 ± 3,32, p= 0,02). Os grupos WTsi, OB e HB demonstraram semelhanças na percepção do clareamento (ΔWID) entre as áreas avaliadas. As comparações intergrupos demonstraram que, nas áreas sob os braquetes, as alterações de cor (ΔEab) foram semelhantes para os grupos, com exceção do WThp (C = 7,97 ± 2,35; WTsi = 8,54 ± 3,63; WThp = 4,69 ± 2,98; OB = 9,31 ± 4,32; HB = 7,41 ± 2,89; p< 0,01). Conclusões: As alterações na cor dos dentes foram efetivas para os procedimentos testados nos grupos WTsi, OB e HB na presença de braquetes metálicos ortodônticos.

ABSTRACT Introduction: Many patients wearing orthodontic appliances request alterations in the shade of their teeth during orthodontic treatment. Objective: This study aimed to evaluate the efficacy of different products for bleaching and whitening under orthodontic brackets. Methods: Seventy bovine incisors were randomly divided into five groups (n = 14): C) non-whitening toothpaste (control); WTsi) hydrated silica whitening toothpaste; WThp) 2% hydrogen peroxide whitening toothpaste; OB) in-office bleaching; and HB) at-home bleaching. Two buccal surface areas were evaluated using the Easyshade spectrophotometer: under the metal bracket (experimental) and around the bracket (control). The paired t-test, ANOVA, and Tukey tests were applied for statistical analysis. Results: Intragroup comparisons showed that in groups C, WThp and HB, there were statistically significant differences in the enamel color changes (ΔEab) between under and around the bracket areas (C - under bracket = 7.97 ± 2.35, around bracket = 2.86 ± 0.81, p< 0.01; WThp - under bracket = 4.69 ± 2.98, around bracket = 2.05 ± 1.41, p< 0.01; HB - under bracket = 7.41 ± 2.89, around bracket: 9.86 ± 3.32, p= 0.02). Groups WTsi, OB and HB presented similar perception of tooth whiteness (ΔWID) between the tested areas. Intergroup comparisons demonstrated that under the bracket area, the color change (ΔEab) was similar for all groups, except WThp (C = 7.97 ± 2.35; WTsi = 8.54 ± 3.63; WThp = 4.69 ± 2.98; OB = 9.31 ± 4.32; HB = 7.41 ± 2.89; p< 0.01). Conclusions: The dental color changes were effective for the products tested in groups WTsi, OB and HB in the presence of metallic orthodontic 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.

ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires.

RESUMO Objetivo: o objetivo do presente estudo foi comparar a eficiência de dois protocolos de intrusão de molares superiores com dois e três mini-implantes. Métodos: foram selecionados 25 primeiros molares superiores extruídos por perda de seus antagonistas, de pacientes adultos. A amostra foi dividida em dois grupos, de acordo com o protocolo de intrusão, com dois ou três mini-implantes: o Grupo 1 consistiu de 15 molares que sofreram intrusão com dois mini-implantes; o Grupo 2 foi constituído por 10 molares intruídos por três mini-implantes. As alterações com o tratamento foram analisadas em telerradiografias em norma lateral ao início e ao final da intrusão dos molares superiores. Resultados: os resultados mostraram que não houve diferença na eficiência dos dois protocolos de intrusão. Concluiu-se que molares superiores extruídos podem ser intruídos, com eficiência semelhante, por meio de dois ou três mini-implantes.

ABSTRACT Objective: The aim of this study was to compare the efficiency of two protocols for maxillary molar intrusion with two or three mini-implants. Methods: Twenty five maxillary first molars extruded for loss of their antagonists in adult subjects were selected. The sample was divided into two groups, according to the intrusion protocol with two or three mini-implants. Group 1 consisted of 15 molars that were intruded by two mini-implants. Group 2 consisted of 10 molars intruded by three mini-implants. Changes with treatment were analyzed in lateral cephalograms at the beginning and at the end of intrusion of maxillary molars. Results: Results showed that there was no difference in efficiency for the two intrusion protocols. It was concluded that extruded maxillary molars can be intruded with two or three mini-implants with similar efficiency.

Resumo Objetivo: o objetivo deste estudo foi comparar a expressão do torque em braquetes autoligáveis ativos e passivos e nos convencionais. Métodos: no total, 300 segmentos de fio de aço inoxidável 0,019" x 0,025" foram usados. Seis diferentes marcas de braquetes foram analisadas (Damon 3MX, Portia, In-Ovation R, Bioquick, Roth SLI, Roth Max). Os momentos de torque foram medidos em 120, 240, 360 e 480, utilizando-se um dispositivo de torção de fio associado a uma máquina de ensaios universal. Os dados obtidos foram comparados pela análise de variância, seguida de teste de Tukey para comparações múltiplas. A análise de regressão foi realizada pelo método dos mínimos quadrados, para gerar uma equação matemática da curva ótima de cada marca de braquete. Resultados: foram observadas diferenças estatisticamente significativas na expressão do torque entre todas as marcas de braquetes avaliadas e em todas as torções testadas (p < 0,05). Encontrou-se que o Bioquick apresentou a menor expressão do torque em todas as torções testadas; em contraste, o braquete Damon 3MX apresentou a maior expressão do torque até a torção de 360. Conclusões: o sistema de ligação entre fio e braquete (autoligável ativo ou passivo, ou convencional com ligadura elástica) parece não interferir na expressão final do torque, a qual é dependente da interação entre o fio e o braquete escolhido para ser utilizado na mecânica ortodôntica.

Abstract Objective: The aim of this study was to compare torque expression in active and passive self-ligating and conventional brackets. Methods: A total of 300 segments of stainless steel wire 0.019 x 0.025-in and six different brands of brackets (Damon 3MX, Portia, In-Ovation R, Bioquick, Roth SLI and Roth Max) were used. Torque moments were measured at 12°, 24°, 36° and 48°, using a wire torsion device associated with a universal testing machine. The data obtained were compared by analysis of variance followed by Tukey test for multiple comparisons. Regression analysis was performed by the least-squares method to generate the mathematical equation of the optimal curve for each brand of bracket. Results: Statistically significant differences were observed in the expression of torque among all evaluated bracket brands in all evaluated torsions (p < 0.05). It was found that Bioquick presented the lowest torque expression in all tested torsions; in contrast, Damon 3MX bracket presented the highest torque expression up to 36° torsion. Conclusions: The connection system between wire/bracket (active, passive self-ligating or conventional with elastic ligature) seems not to interfere in the final torque expression, the latter being probably dependent on the interaction between the wire and the bracket chosen for orthodontic mechanics.

PURPOSE: To evaluate the effect of simvastatin on relapse of tooth movement in rats using microtomography (micro CT), as well as the correlation of bone density with the orthodontic relapse.METHODS: Twenty-five adult male Wistar rats, divided into two groups, had stainless steel springs installed on left maxillary first molar. The molars were moved for 18 days, and after removing the springs, were applied by oral gavage, 5mg/kg of simvastatin in the experimental group for 20 days. Tooth relapse was assessed with a micro CT scanner, and the images chosen through the Data Viewer software 1.5.0.0 had their measurement guides made and checked by the software Image ProR plus 5.1, and compared by Mann-Whitney test. After rats were sacrificed, bone mineral density was evaluated by micro CT through the software CT Analyzer 1.13 and compared by independent T-test, as well as by Spearman correlation test.RESULTS: Relapse and bone mineral density (BMD) was lower in the experimental group than in the control group, however without a statistically significant difference.CONCLUSION: Simvastatin did not inhibit the relapse of tooth movement in rats, and there was no correlation between bone density and orthodontic relapse.

This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0) was tested: no difference between tooth size discrepancies (overall and anterior) would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321), Class II (n = 324), and Class III patients (n = 66). The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Bolton’s method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups.

Anterior spaces may interfere with smile attractiveness and compromise dentofacial harmony. They are among the most frequent reasons why patients seek orthodontic treatment. However, midline diastema is commonly cited as a malocclusion with high relapse incidence by orthodontists. Objectives: This study aimed to evaluate the stability of maxillary interincisor diastemas closure and the association of their relapse and interincisor width, overjet, overbite and root parallelism. Material and Methods: Sample comprised 30 patients with at least a pretreatment midline diastema of 0.5 mm or greater after eruption of the maxillary permanent canines. Dental casts and panoramic radiographs were taken at pretreatment, posttreatment and postretention. Results: Before treatment, midline diastema width was 1.52 mm (SD=0.88) and right and left lateral diastema widths were 0.55 mm (SD=0.56) and 0.57 mm (SD=0.53), respectively. According to repeated measures analysis of variance, only midline diastema demonstrated significant relapse. In the overall sample the average relapse of midline diastema was 0.49 mm (SD=0.66), whilst the unstable patients showed a mean space reopening of 0.78 mm (SD=0.66). Diastema closure in the area between central and lateral incisors showed great stability. Multivariate correlation tests showed that only initial diastema width (β=0.60) and relapse of overjet (β=0.39) presented association with relapse of midline diastema. Conclusions: Midline diastema relapse was statistically significant and occurred in 60% of the sample, while lateral diastemas closure remained stable after treatment. Only initial diastema width and overjet relapse showed association with relapse of midline diastema. There was no association between relapse of interincisor diastema and root parallelism.

OBJETIVO: a proposta desse estudo foi avaliar cefalometricamente os efeitos esqueléticos e dentoalveolares do tratamento da má oclusão de Classe II com o distalizador Jones jig, seguido do uso do aparelho fixo corretivo. MÉTODOS: a amostra constituiu de 25 pacientes com má oclusão de Classe II, tratados com o distalizador Jones Jig, seguido do uso de aparelho fixo corretivo, com média de idade inicial de 12,90 anos. O tempo médio de tratamento ortodôntico total foi de 3,89 anos. A fase de distalização durou 0,85 anos, e a fase de aparelho fixo pós-distalização foi de 3,04 anos. Foram utilizadas as telerradiografias nos tempos inicial (T1), pós-distalização (T2) e final do aparelho fixo (T3). Para comparação intragrupo nos três tempos avaliados, foram utilizados os testes ANOVA dependente e de Tukey. RESULTADOS: os resultados demonstraram que o Jones Jig não interferiu no componente maxilar e mandibular, e não promoveu alterações na relação maxilomandibular. O Jones Jig promoveu distalização dos primeiros molares, com perda de ancoragem, mesialização e extrusão significativa dos primeiros e segundos pré-molares, e aumento significativo da altura facial anteroinferior ao final do tratamento. A maioria dos efeitos adversos ocorridos na fase de distalização intrabucal são posteriormente corrigidos durante a mecânica corretiva. Verificou-se vestibularização e protrusão dos incisivos inferiores. Ao final do tratamento, foi observada a correção dos trespasses horizontal e vertical. CONCLUSÕES: o distalizador Jones Jig promoveu a distalização dos primeiros molares, com perda de ancoragem, representada pela mesialização e extrusão significativa dos primeiros e segundos pré-molares, e aumento significativo da altura facial anteroinferior.

OBJECTIVE: The aim of this study was to cephalometrically assess the skeletal and dentoalveolar effects of Class II malocclusion treatment performed with the Jones Jig appliance followed by fixed appliances. METHODS: The sample comprised 25 patients with Class II malocclusion treated with the Jones Jig appliance followed by fixed appliances, at a mean initial age of 12.90 years old. The mean time of the entire orthodontic treatment was 3.89 years. The distalization phase lasted for 0.85 years, after which the fixed appliance was used for 3.04 years. Cephalograms were used at initial (T1), post-distalization (T2) and final phases of treatment (T3). For intragroup comparison of the three phases evaluated, dependent ANOVA and Tukey tests were used. RESULTS: Jones Jig appliance did not interfere in the maxillary and mandibular component and did not change maxillomandibular relationship. Jones Jig appliance promoted distalization of first molars with anchorage loss, mesialization and significant extrusion of first and second premolars, as well as a significant increase in anterior face height at the end of treatment. The majority of adverse effects that occur during intraoral distalization are subsequently corrected during corrective mechanics. Buccal inclination and protrusion of mandibular incisors were identified. By the end of treatment, correction of overjet and overbite was observed. CONCLUSIONS: Jones Jig appliance promoted distalization of first molars with anchorage loss represented by significant mesial movement and extrusion of first and second premolars, in addition to a significant increase in anterior face height.

Objetivo: comparar a aceitabilidade e a efetividade do uso de anestésico tópico e anestésico infiltrativo para inserção de mini-implantes ortodônticos, utilizados como dispositivos de ancoragem temporária. Métodos: foram selecionados 40 pacientes, sendo 17 do sexo masculino e 23 do sexo feminino, com idade média de 26 anos, todos em tratamento ortodôntico e necessitando de reforço de ancoragem. Em todos os indivíduos foram instalados mini-implantes bilateralmente em maxila, sendo em um dos lados com anestesia infiltrativa e do lado oposto com anestesia tópica. Esses 40 pacientes responderam dois questionários, sendo um pré- e outro pós-operatório, e foram obtidos índices de dor por meio da escala visual análoga (VAS). Os dados coletados foram analisados por meio de estatística descritiva e os índices de dor foram comparados por meio do teste não-paramétrico de Mann-Whitney. Resultados: verificou-se que 60% dos pacientes se sentiram mais confortáveis com a utilização de anestesia tópica para a inserção dos mini-implantes; 72,5% dos pacientes apontaram a pressão durante a inserção do dispositivo de ancoragem como a sensação mais desagradável de todo o processo; 62,5% dos pacientes sentiram mais dor com o uso de anestesia tópica. Conclusão: concluiu-se que os pacientes apresentaram menor índice de dor com o uso de anestesia infiltrativa e que, também, preferiram esse tipo de anestésico.

Objective: To compare the acceptability and effectiveness of topical and infiltration anesthesia for placement of mini-implants used as temporary anchorage devices. Methods: The sample comprised 40 patients, 17 males and 23 females, whose mean age was 26 years old and who were all undergoing orthodontic treatment and in need for anchorage reinforcement. Mini-implants were bilaterally placed in the maxilla of all individuals, with infiltration anesthesia on one side and topical anesthesia on the other. These 40 patients completed two questionnaires, one before and another after mini-implant placement and pain was measured through a visual analog scale (VAS). The data collected were analyzed using descriptive statistics and the measurements of pain were compared by means of the non-parametric test of Mann-Whitney. Results: It was found that 60% of patients felt more comfortable with the use of topical anesthesia for mini-implant placement; 72.5% of patients described the occurrence of pressure during placement of the anchorage device as the most unpleasant sensation of the entire process; 62.5% of patients felt more pain with the use of topical anesthesia. Conclusion: It was concluded that patients had less pain with the use of infiltration anesthesia, and also preferred this type of anesthetic.

Objectives: The shape memory resulting from the superelasticity and thermoelastic effect is the main characteristic of thermally activated NiTi archwires and is closely related to the transition temperature range (TTR). The aim of this study was to evaluate the TTR of thermally activated NiTi archwires commercially available. Material and Methods: Seven different brands of 0.019"x0.025" thermally activated nickel-titanium archwires were tested as received by differential scanning calorimetry (DSC) over the temperature range from -100°C to 150°C at 10°C/min. Results: All thermally activated NiTi archwires analyzed presented stage transformation during thermal scanning with final austenitic temperature (Af) ranging from 20.39°C to 45.42°C. Three brands of NiTi archwires presented Af close to the room temperature and, this way, do not present properties of shape memory and pseudoelasticity that are desirable in clinical applications. Conclusions: The thermally activated NiTi archwires present great variability in the TTR and the elastic parameters of each NiTi archwire should be provided by the manufacturers, to allow achievement of the best clinical performance possible.

OBJETIVO: avaliar os efeitos dentoesqueléticos do tratamento da má oclusão de Classe II com o aparelho Twin Block comparado a um grupo controle. MÉTODOS: o grupo experimental foi composto por 20 pacientes com idade inicial média de 11,76 anos e que foram tratados por um período de 1,13 anos. O grupo controle foi composto por 25 indivíduos com idade inicial média de 11,39 anos e que foram acompanhados por um período de 1,07 anos. Telerradiografias em norma lateral foram obtidas ao início e final do tratamento para avaliar as alterações decorrentes do tratamento. A comparação intergrupos foi realizada por meio do teste qui-quadrado e do teste t independente. RESULTADOS: o aparelho Twin Block não apresentou alterações significativas no componente maxilar. O componente mandibular revelou um aumento estatisticamente significativo do crescimento efetivo da mandíbula (Co-Gn) e uma melhora significativa da relação existente entre as bases ósseas. Os componentes dentoalveolar superior e inferior apresentaram um significativo componente de inclinação dos dentes anteriores em ambas as arcadas. Os incisivos superiores foram inclinados para lingual e retruídos, ao passo que os incisivos inferiores foram inclinados para vestibular e protruídos. CONCLUSÕES: o aparelho Twin Block apresenta grande efetividade na correção da má oclusão de Classe II esquelética em pacientes em fase de crescimento. A maior parte das alterações ocorridas é de natureza dentoalveolar, com um grande componente de inclinação dentária associado a um significativo efeito esquelético na mandíbula.

OBJECTIVE: The aim of this study was to assess the dentoskeletal effects of Class II malocclusion treatment performed with the Twin Block appliance. METHODS: The experimental group comprised 20 individuals with initial mean age of 11.76 years and was treated for a period of 1.13 years. The control group comprised 25 individuals with initial mean age of 11.39 years and a follow-up period of 1.07 years. Lateral cephalograms were taken at treatment onset and completion to assess treatment outcomes. Intergroup comparison was performed by means of the chi-square and independent t tests. RESULTS: The Twin Block appliance did not show significant effects on the maxillary component. The mandibular component showed a statistically significant increase in the effective mandibular length (Co-Gn) and significant improvement in the maxillomandibular relationship. The maxillary and mandibular dentoalveolar components presented a significant inclination of anterior teeth in both arches. The maxillary incisors were lingually tipped and retruded, while the mandibular incisors were labially tipped and protruded. CONCLUSIONS: The Twin Block appliance has great effectiveness for correction of skeletal Class II malocclusion in individuals with growth potential. Most changes are of dentoalveolar nature with a large component of tooth inclination associated with a significant skeletal effect on the mandible.

Objective: This prospective study assessed the stability of Class II treatment with the Bionator, followed by fixed appliances, 10 years after treatment. Material and Methods: The experimental group comprised 23 patients of both sexes (10 boys, 13 girls) at a mean initial age of 11.74 years (late mixed or early permanent dentitions), treated for a mean period of 3.55 years who were evaluated at three stages: initial (T1), final (T2) and long-term posttreatment (T3). A total of 69 lateral cephalograms were evaluated and 69 dental casts were measured using the PAR index. The difference between initial and final PAR indexes, the percentage of occlusal improvement obtained with therapy and the percentage of relapse were calculated, using the PAR index. The variables were compared by repeated measures analysis of variance (ANOVA) followed by Tukey tests. Results: The significant improvement in apical base relationship, the palatal inclination of the maxillary incisors and the labial inclination of the mandibular incisors, and the significant improvement in molar relationship and reduction of overjet and overbite, obtained with treatment, remained stable in the long-term posttreatment period. There was also significant improvement in the occlusal relationships which remained stable in the long-term posttreatment period. The percentage of occlusal improvement obtained was of 81.78% and the percentage of relapse was of 4.90%. Conclusions: Treatment of Class II division 1 malocclusions with the Bionator associated with fixed appliances showed to be stable in the long-term posttreatment period.

OBJETIVO: comparar, por meio de tomografia computadorizada, a alteração da espessura óssea alveolar na região de incisivos superiores durante o tratamento ortodôntico, com e sem extração dentária. MÉTODOS: foram avaliados 12 pacientes, divididos em dois grupos: G1, seis pacientes tratados com extrações de dois primeiros pré-molares superiores, com idade média inicial de 15,83 anos, e tratados por um tempo médio de 2,53 anos; G2, seis pacientes tratados sem extrações, com idade média inicial de 18,26 anos e tratados por um período de 2,39 anos. Foram utilizadas tomografias computadorizadas, telerradiografias em norma lateral e radiografias periapicais ao início (T1) e após 18 meses de tratamento (T2), desde que o espaço da extração já estivesse fechado nos casos tratados com extrações. A comparação intragrupo foi realizada por meio do teste t dependente, e a comparação intergrupos por meio do com o teste t independente. RESULTADOS: o grupo 1 apresentou uma retração e verticalização do incisivo central, enquanto o grupo 2 apresentou uma vestibularização desse dente. Além disso, o grupo 1 apresentou maior aumento da espessura óssea cervical vestibular durante o tratamento, quando comparado ao grupo 2. A incidência de reabsorção radicular não apresentou diferenças significativas entre os grupos. CONCLUSÕES: não houve alteração nas espessuras ósseas alveolares quando comparados casos tratados com e sem extrações, com exceção da espessura óssea vestibular na região cervical dos incisivos superiores.

OBJECTIVE: To compare, through computed tomography, alveolar bone thickness changes at the maxillary incisors area during orthodontic treatment with and without tooth extraction. METHODS: Twelve patients were evaluated. They were divided into 2 groups: G1 - 6 patients treated with extraction of right and left maxillary first premolars, with mean initial age of 15.83 years and mean treatment length of 2.53 years; G2 - 6 patients treated without extraction, with mean initial age of 18.26 years and mean treatment length of 2.39 years. Computed tomographies, lateral cephalograms and periapical radiographs were used at the beginning of the treatment (T1) and 18 months after the treatment had started (T2). Extraction space closure occurred in the extraction cases. Intragroup and intergroup comparisons were performed by dependent and independent t test, respectively. RESULTS: In G1, the central incisor was retracted and uprighted, while in G2 this tooth showed vestibularization. Additionally, G1 presented a higher increase of labial alveolar bone thickness at the cervical third in comparison with G2. The incidence of root resorption did not present significant differences between groups. CONCLUSION: There were no changes in alveolar bone thickness when extraction and nonextraction cases were compared, except for the labial alveolar bone thickness at the cervical third of maxillary incisors.

OBJETIVO: avaliar os efeitos dentoesqueléticos do tratamento da má oclusão de Classe II com o aparelho de Herbst em pacientes que se encontravam na fase pós-pico de crescimento. MÉTODOS: a amostra consistiu de 16 pacientes com má oclusão de Classe II com medianas das idades inicial e final de 14,04 (amplitude 11,50 - 35,66) e 17,14 anos (amplitude 13,68 - 38,64), respectivamente, que foram tratados por um período médio de 2,52 anos. Telerradiografias em norma lateral foram obtidas ao início e final do tratamento para avaliar as alterações decorrentes do tratamento. Os modelos de gesso iniciais foram utilizados para avaliar o trespasse horizontal e a severidade da relação anteroposterior existente entre os molares ao início do tratamento. As alterações cefalométricas entre as fases inicial e final foram comparadas pelo teste não-paramétrico de Wilcoxon. RESULTADOS: os resultados mostraram que o aparelho de Herbst não promoveu alterações significativas no componente maxilar, o comprimento efetivo da mandíbula aumentou significativamente, sem promover uma melhoria da relação maxilomandibular. As alterações dos componentes dentoalveolares superiores e inferiores mostraram que os incisivos superiores apresentaram uma retrusão e inclinação lingual, ao passo que os incisivos inferiores evidenciaram um aumento na protrusão e inclinação para vestibular. As relações dentárias apresentaram uma melhora significativa com o tratamento. CONCLUSÃO: com base nos resultados desse trabalho, concluiu-se que os efeitos da terapia com o aparelho de Herbst em pacientes na fase pós-pico de crescimento são de natureza predominantemente dentoalveolar.

OBJECTIVE: The objective of this study was to evaluate dentoskeletal effects in the treatment of Class II malocclusion performed with the Herbst appliance in patients at post-peak stage of growth. METHODS: The sample consisted of 16 patients with Class II malocclusion and average initial and final ages of 14.04 (ranging from 11.50 to 35.66) and 17.14 (ranging from 13.68 to 38.64) years, respectively, who were treated for an mean time of 2.52 years. Lateral cephalograms were obtained at treatment onset (T1) and completion (T2) to evaluate the effects of therapy. Initial dental casts were also used to evaluate the overjet and the anteroposterior severity of molar relationship at treatment onset. The cephalometric changes between initial and final stages were compared by means of the non-parametric Wilcoxon test. RESULTS: The results showed that the Herbst appliance did not promote significant changes in the maxillary component and the effective length of the mandible significantly increased without improving the maxillomandibular relationship. Changes in the maxillary and mandibular dentoalveolar components revealed that the maxillary incisors exhibited retrusion and lingual tipping, while the mandibular incisors presented increased protrusion and buccal tipping. The dental relationships exhibited significant improvements with the treatment. CONCLUSION: Based on the present results, it was concluded that the effects of treatment performed with the Herbst appliance in patients at post-peak stage of growth are predominantly of dentoalveolar nature.