Maxillary alveolar bone evaluation following dentoalveolar expansion with clear aligners in adults: A cone-beam computed tomography study.

Objective: To investigate the effects of maxillary orthodontic expansion on the alveolar bone tissue in adult patients treated with aligners by using cone-beam computed tomography. Methods: Thirty patients (22 females and 8 males; mean age: 36.3 years) were treated with Invisalign® aligners. Cone-beam computed tomography and digital models were obtained before (T0) and after (T1) upper arch expansion. The bone thicknesses in the cervical, middle, and apical areas of the incisors, canines, premolar, and first molars were buccally and palatally measured, totaling 96 areas and 2,880 measurements. The buccolingual inclinations and transverse measurements of the teeth were obtained from digital models to correlate them with the bone changes. The statistical tests used were Student's t-test, analysis of variance, and Pearson's correlation tests (p < 0.05). Results: From the 96 areas evaluated, 84 revealed an increase or stability in the alveolar bone thickness and twelve displayed significant bone loss. Bone changes did not correlate with the tooth inclination and transverse measurements. Conclusions: Within the limitation of the present study, mild levels of upper arch expansion obtained with Invisalign® aligners in adult patients did not result in any clinically significant loss of alveolar bone thickness.

Evaluation of Enamel Roughness in Vitro After Orthodontic Bracket Debonding Using Different Methods of Residual Adhesive Removal.

OBJECTIVE: The aim of the present study was to compare different techniques for resin remnant removal (RRR) after orthodontic bracket debonding and to evaluate alterations on the dental enamel caused by these methods. The null hypothesis tested was that there is no difference between RRR techniques in relationship the changes caused on the dental enamel. METHODS: A total of 75 bovine mandibular permanent incisors were used in the study. Brackets were bonded and debonded in each tooth in two experimental regions. Five RRR techniques were used in the experimental groups (n=15): Group 1-diamond bur (6-bladed), Group 2-diamond bur (12-bladed), Group 3-diamond bur (30-bladed), Group 4-aluminum oxide sandblasting (AOS), and Group 5-Er:YAG laser. Enamel surface was evaluated using profilometry, and surface roughness analysis was performed at three time intervals: before bracket bonding, after RRR techniques, and after final polishing. Qualitative analyses of the enamel surfaces were performed using scanning electron microscopy. RESULTS: Multiblade burs showed the best results, and the 30-bladed bur created a less irregular enamel surface. AOS caused greater enamel wear, and Er:YAG laser caused more surface irregularity. CONCLUSION: The null hypothesis was rejected. The multiblade burs were the least harmful than the other techniques. Enamel surface roughness after using the 30-blade bur was similar to the original enamel. These results indicate that the type of bur tested (30-bladed) can be indicated to remove resin remnants after bracket debonding.

Early Treatment of Failure of Eruption of a Permanent Molar.

Failure of eruption of a permanent first molar is a relatively infrequent clinical condition that affects the normal development of dentition and may cause malocclusion. There are two conditions that might result in failure of eruption: (1) mechanical failure (ankylosis) and (2) primary failure of eruption, with different clinical features and therapeutic approaches for each. It is often challenging for orthodontists and pediatric dentists to establish differential diagnoses of these conditions to ensure a successful treatment outcome. The purpose of this case report is to discuss the diagnosis and treatment of a failure of eruption of a permanent first molar. (J Dent Child 2019;86(3):150-3).

Genetic polymorphism in ESR2 and risk of tooth agenesis

Introduction: Tooth agenesis (TA) is the congenital absence of teeth. Several studies have proposed a strong genetic background for this condition. Aim: The present cross-sectional study aimed to evaluate whether genetic polymorphisms in the genes that code for estrogen receptors ( ESR1 and ESR2 ) are associated with the presence of isolated TA in a Brazilian sample. Methods: Panoramic radiographs of 142 orthodontic patients were assessed to determine TA of permanent teeth (excluding third molars). DNA of patients was extracted from buccal cells from saliva to evaluate genetic polymorphisms in ESR1 ( rs2234693 and rs9340799 ) and ESR2 ( rs1256049 and rs4986938 ) by genotyping using the real-time PCR technique. For statistical analyses, associations between the distributions of the alleles and genotypes, and the ocurrence of TA were assessed for each genetic polymorphism, with an established alpha of 5%. Results: Thirteen patients had at least 1 congenital missing tooth. The number of congenitally missing teeth ranged from 1 to 11. The genetic polymorphisms rs2234693 and rs9340799 in ESR1 and rs1256049 in ESR2 were not associated with TA ( p > 0.05) . For the genetic polymorphism rs4986938 in ESR2, the genotype and allele distributions were significantly different between the patients with and without TA ( p < 0.05). The CC genotype and the C allele were overrepresented in the TA patients. Conclusion: The genetic polymorphism rs4986938 in ESR2 was associated with the ocurrence o f TA.

Introdução: A agenesia dentária (AD) é a ausência congênita de um ou mais dentes. Vários estudos vêm sugerindo o forte componente genético para essa condição. Objetivo: O presente estudo teve como objetivo avaliar se os polimorfismos genéticos nos genes que codificam os receptores de estrógeno ( ESR1 e ESR2 ) estão associados à ocorrrência de AD isolada em uma amostra brasileira. Métodos: Radiografias panorâmicas de 142 pacientes ortodônticos foram avaliadas para determinar AD de dentes permanentes (excluindo terceiros molares). O DNA dos pacientes foi extraído das células da mucosa bucal contidas na saliva para avaliar polimorfismos genéticos em ESR1 ( rs2234693 e rs9340799 ) e ESR2 ( rs1256049 e rs4986938 ) por genotipagem usando a técnica de PCR em tempo real. Para análises estatísticas, associações entre as distribuições dos alelos e genótipos e a ocorrrência de AD foram avaliadas para cada polimorfismo genético, com um alfa estabelecido de 5%. Resultados: Treze pacientes tiveram pelo menos 1 dente congenitamente ausente. O número de dentes congenitamente ausentes variou de 1 a 11. Os polimorfismos genéticos rs2234693 e rs9340799 no ESR1 e rs1256049 no ESR2 não foram associados à AD ( p > 0,05). Para o polimorfismo genético rs4986938 no ESR2 , as distribuições dos genótipos e dos alelos foram estatisticamente diferentes entre os pacientes com e sem AD ( p < 0,05). O genótipo CC e o alelo C estavam super-representados nos pacientes com AD. Conclusão: Houve associação entre o polimorfismo genético rs4986938 no ESR2 e a ocorrrência de AD.

Genotoxic effects in oral mucosal cells caused by the use of orthodontic fixed appliances in patients after short and long periods of treatment.

OBJECTIVE: This study aimed to evaluate the genotoxic effects in the oral epithelial cells of patients undergoing fixed orthodontic treatment and to compare these to a control group without treatment. The null hypothesis to be tested is that corrective orthodontic treatment at different periods does not cause genotoxic effects in patients. MATERIAL AND METHODS: An observational cross-sectional study including 74 patients enrolled in corrective orthodontic treatment and 21 control patients, between 11 and 35 years of age, of both genders, participated in the research. Patients undergoing treatment were divided into four treatment groups differentiated by treatment periods: G1, n = 21 (1 month to 12 months); G2, n = 21 (13 to 24 months); G3, n = 23 (25 to 48 months); and G4, n = 9 (over 48 months). Cells were collected by scraping the internal side of the cheek and subsequently placed in tubes containing 0.9% sodium chloride solution. The sample underwent evaluation for genotoxic effects by means of the micronucleus test (MNT). Bivariate analyses were performed using parametric tests (t test or ANOVA) and nonparametric tests (Chi-square test, Kruskal-Wallis test, Dunn post-test). The adopted level of significance was 5%. RESULTS: Statistically significant differences for any of the genotoxic abnormalities (binucleated, trinucleated, karyolysis, piknosis, nuclear buds) were not found except for karyolysis, which was higher in the control group than in G4 (p < 0.05). CONCLUSIONS: This study did not demonstrate evidence of genotoxic effects even after long periods of corrective orthodontic treatment. CLINICAL RELEVANCE: This study explores genotoxic effects in fixed orthodontic patients.

Orofacial Myofunctional Evaluation Protocol for older people: validity, psychometric properties, and association with oral health and age.

PURPOSE: To develop a comprehensive assessment protocol for identifying, classifying and grading changes in stomatognathic system components and functions of older people, to determine its psychometric properties and verify its association with oral health and age. METHODS: The content validity of the Orofacial Myofunctional Evaluation with Scores for Elders protocol (OMES-Elders) was established based on the literature. The protocol contains three domains: appearance/posture, mobility, and functions of the stomatognathic system. Eighty-two healthy elder volunteers (mean age 69±7.24 years) were evaluated using the OMES-Elders. A test-screening for orofacial disorders (reference) was used to analyze the concurrent validity (correlation test), sensitivity, specificity and accuracy (Receiver Operating Characteristic Curve: ROC curve) of the OMES-Elders. The association of the OMES-Elders scores with the Oral Health Index (OHX) and age in the sample was tested. RESULTS: There was a significant correlation between the OMES-Elders and the reference test (p < 0.001). Reliability coefficients ranged from good (0.89) to excellent (0.99). The OMES-Elders protocol had a sensitivity of 82.9%, specificity of 83.3% and accuracy of 0.83. The scores of the protocol were significantly lower in individuals with worse oral health (OHX ≤ 61%), although individuals with adequate oral health (OHX ≥ 90%) also had myofunctional impairments. The predictors OHX and age explained, respectively, 33% and 30% of the variance in the OMES-Elders total score. CONCLUSION: As the first specific orofacial myofunctional evaluation of older people, the OMES-Elders protocol proved to be valid, reliable and its total score was associated with oral health and age.

Quantification of Streptococcus mutans in Different Types of Ligature Wires and Elastomeric Chains.

This study aimed to test the hypothesis that Streptococcus mutans contamination levels differ according to the type of the orthodontic ligature. Thirteen patients were selected. Each quadrant was randomly subjected to one of the following ligature-use protocols: I) elastomeric chain, II) steel ligature crossed over the archwire, III) steel ligature crossed under the archwire, and IV) steel ligature in a figure-eight pattern under the archwire. After seven days, the devices were removed and the Streptococcus mutans colony-forming unit count per mg of biofilm weight was determined. Twelve specimens (n=3) were also processed for scanning electron microscopy analysis. ANOVA and Tukey-Kramer test were used for comparisons to assess S. mutans differences between groups at a 5% significance level. There was no statistical difference in detectable levels of S. mutans among the groups (p=0.294). Scanning electron microscopy results showed abundant biofilms and microbial contamination in all groups. In conclusion, S. mutans contamination levels are similar in the different orthodontic ligatures.

Quantification of Streptococcus mutans in Different Types of Ligature Wires and Elastomeric Chains

Abstract This study aimed to test the hypothesis that Streptococcus mutans contamination levels differ according to the type of the orthodontic ligature. Thirteen patients were selected. Each quadrant was randomly subjected to one of the following ligature-use protocols: I) elastomeric chain, II) steel ligature crossed over the archwire, III) steel ligature crossed under the archwire, and IV) steel ligature in a figure-eight pattern under the archwire. After seven days, the devices were removed and the Streptococcus mutans colony-forming unit count per mg of biofilm weight was determined. Twelve specimens (n=3) were also processed for scanning electron microscopy analysis. ANOVA and Tukey-Kramer test were used for comparisons to assess S. mutans differences between groups at a 5% significance level. There was no statistical difference in detectable levels of S. mutans among the groups (p=0.294). Scanning electron microscopy results showed abundant biofilms and microbial contamination in all groups. In conclusion, S. mutans contamination levels are similar in the different orthodontic ligatures.

Resumo Este estudo teve como objetivo testar a hipótese de que os níveis de contaminação de Streptococcus mutans diferem de acordo com o tipo de ligadura ortodôntica. Treze pacientes foram selecionados. Cada quadrante foi submetido aleatoriamente a um dos seguintes protocolos de uso de ligadura: I) ligadura elastomérica, II) ligadura de aço trançada sobre o arco, III) ligadura de aço trançada sob o arco e IV) ligadura de aço em um padrão de "oito" sob o arco. Após sete dias, os dispositivos foram removidos e a contagem das unidades formadoras de colônia de S. mutans por mg de peso de biofilme foi determinada. Doze espécimes (n = 3) também foram processados para análise por microscopia eletrônica de varredura. Análise de variância e teste de Tukey-Kramer foram utilizados para comparações a fim de avaliar as diferenças de níveis de S. mutans entre os grupos com significância de 5%. Não houve diferença estatisticamente significante em níveis detectáveis de S. mutans entre os grupos (p = 0,294). Os resultados da microscopia eletrônica de varredura mostraram biofilmes abundantes e contaminação microbiana em todos os grupos. Em conclusão, os níveis de contaminação de S. mutans são semelhantes nas diferentes ligaduras ortodônticas.

Traction of impacted canines in a skeletal Class III malocclusion: A challenging orthodontic treatment.

This case report describes the successful traction of 2 severely impacted canines. The patient, a 7-year-old girl, had good general health, nasal breathing, crossbite of the lateral incisors and canines, and a Class I molar relationship. The panoramic radiograph showed that the permanent canines were positioned above the roots of the lateral incisors, with the right canine in an accentuated inclination. The cephalometric analysis showed a skeletal Class III malocclusion with a predominance of horizontal growth. The Haas appliance associated with maxillary protraction was used during the first stage of treatment for 14 months. The second stage included the extraction of the deciduous molars, distal movement of the permanent molars to create space, and traction of the canines, and was associated with complete orthodontic treatment. The patient showed good esthetic and functional results at the end of treatment, verified by the stability over a period of 8 years after retention.

Biofilm formation in Haas palatal expanders with and without use of an antimicrobial agent: an in situ study.

Orthodontic appliances causes specific alterations in oral environment, including reduction of pH, increase of dental biofilm and elevation of salivary microbial levels, causing an increased risk for dental caries. This study evaluated, using microbial culture and scanning electron microscopy (SEM), the in situ contamination by mutans streptococci (MS) of different surfaces of Haas palatal expanders with and without use of chlorhexidine gluconate mouthrinses (CHX). Thirty-four patients were randomly assigned to two groups (n = 17/group), using placebo (Group I) and 0.12% CHX (Group II-Periogard® ) mouthrinses twice a week. After 4 months, appliances were submitted to microbiological processing and after fragments were analyzed by SEM. Mann-Whitney U test (α = 5%) was used to assess differences between groups on the appliances' different surfaces and to compare the contamination on the free and nonfree surfaces of these components. There was no difference (p = 0.999) between groups regarding the number of MS colonies/biofilms on the nonfree surfaces, which showed intense contamination. However, free surfaces of Group II presented less contamination (p < 0.001) than those of Group I in all appliances' components. Results of the microbial culture were confirmed by SEM. Use of 0.12% CHX was effective in reducing the formation of MS colonies/biofilms on free surfaces of Haas expanders, in situ.

Orofacial Myofunctional Evaluation Protocol for older people: validity, psychometric properties, and association with oral health and age / Protocolo de Avaliação Miofuncional Orofacial para pessoas idosas: validade, propriedades psicométricas e associação com saúde oral e idade

ABSTRACT Purpose To develop a comprehensive assessment protocol for identifying, classifying and grading changes in stomatognathic system components and functions of older people, to determine its psychometric properties and verify its association with oral health and age. Methods The content validity of the Orofacial Myofunctional Evaluation with Scores for Elders protocol (OMES-Elders) was established based on the literature. The protocol contains three domains: appearance/posture, mobility, and functions of the stomatognathic system. Eighty-two healthy elder volunteers (mean age 69±7.24 years) were evaluated using the OMES-Elders. A test-screening for orofacial disorders (reference) was used to analyze the concurrent validity (correlation test), sensitivity, specificity and accuracy (Receiver Operating Characteristic Curve: ROC curve) of the OMES-Elders. The association of the OMES-Elders scores with the Oral Health Index (OHX) and age in the sample was tested. Results There was a significant correlation between the OMES-Elders and the reference test (p < 0.001). Reliability coefficients ranged from good (0.89) to excellent (0.99). The OMES-Elders protocol had a sensitivity of 82.9%, specificity of 83.3% and accuracy of 0.83. The scores of the protocol were significantly lower in individuals with worse oral health (OHX ≤ 61%), although individuals with adequate oral health (OHX ≥ 90%) also had myofunctional impairments. The predictors OHX and age explained, respectively, 33% and 30% of the variance in the OMES-Elders total score. Conclusion As the first specific orofacial myofunctional evaluation of older people, the OMES-Elders protocol proved to be valid, reliable and its total score was associated with oral health and age.

RESUMO Objetivo Desenvolver um protocolo de avaliação abrangente para identificar, classificar e graduar as mudanças nos componentes e funções do sistema estomatognático em pessoas idosas, determinar suas propriedades psicométricas e verificar a associação com a saúde oral e a idade. Método A validade de conteúdo do protocolo de Avaliação Miofuncional Orofacial com Escores para Idosos (AMIOFE-I), que contém três domínios, aparência/postura, mobilidade e funções do sistema estomatognático, foi estabelecida com base na literatura. Oitenta e dois voluntários idosos (média de idade 69±7,24 anos) foram avaliados usando o AMIOFE-I. Um teste de triagem de distúrbios miofuncionais (referência) foi empregado para as análises de validade concorrente (teste de correlação), sensibilidade, especificidade e acurácia (Receiver Operating Characteristic Curve: curva ROC) do AMIOFE-I. Também foi analisada a associação dos escores do AMIOFE-I com o índice de saúde oral (ISO), determinado na amostra, e à idade. Resultados Houve uma significante correlação entre o AMIOFE e o teste de referência. Os coeficientes de confiabilidade variaram de bom a excelente. O AMIOFE apresentou sensibilidade de 82,9%, especificidade de 83,3% e acurácia de 0,83. Os escores do AMIOFE-I foram significantemente menores em indivíduos com piores ISO (≤ 61%), contudo aqueles com adequada saúde oral (ISO ≥ 90%) também tinha prejuízos miofuncionais. Os preditores ISO e idade explicaram respectivamente 33% e 30% da variância no escore total do AMIOFE-I. Conclusão O protocolo AMIOFE-I, o primeiro específico para a avaliação miofuncional de idosos, mostrou-se válido, confiável e seu escore total foi associado à saúde oral e à idade.

Tratamento da má oclusão de Classe II subdivisão com distalização assimétrica de molares superiores / Treatment od Class II malocclusion, subdivision with asymmetric distalization of upper molars

A má oclusão de Classe II é caracterizada pela posição distal da arcada inferior em relação à superior, com o centro da cúspide mesiovestibular do primeiro molar permanente superior ocluindo mesialmente ao sulco vestibular do primeiro molar permanente inferior. Sua origem pode ser esquelética, dentária ou uma combinação dos dois fatores. Essa má oclusão é dividida em divisão 1 e 2 e pode apresentar subdivisão. A Classe II subdivisão é encontrada em, aproximadamente, 50% dos casos de classe II de Angle, e é caracterizada pela distoclusão de somente um lado da arcada dentária, com o outro em relação de Classe I de molar. O diagnóstico dessa má oclusão deve ser criterioso para a elaboração de plano de tratamento adequado. Diante de uma má oclusão de Classe II subdivisão, deve-se verificar se a assimetria é dentária ou esquelética, e, quando dentária, se está localizada na arcada inferior ou superior. O tratamento das más oclusões de Classe II subdivisão é abrangente e pode envolver extrações, distalizações ou stripping - dependendo da idade do paciente, do tipo das características da má oclusão. Um dos fatores mais importantes no tratamento da Classe II subdivisão, além de finalizar com os caninos em chave de oclusão, é coincidir as linhas médias dentárias entre si, e elas com a linha média facial. O objetivo desse trabalho foi abordar as principais características da má oclusão de Classe II subdivisão com ênfase no diagnóstico e tratamento, e ilustrá-lo com o relato de dois casos clínicos.

Clinical evaluation of the failure rate of metallic brackets bonded with orthodontic composites.

The purpose of the present study was to evaluate in vivo the failure rate of metallic brackets bonded with two orthodontic composites. Nineteen patients with ages ranging from 10.5 to 38.7 years needing corrective orthodontic treatment were selected for study. The enamel surfaces from second premolars to second premolars were treated with Transbond Plus-Self Etching Primer (3M Unitek). Next, 380 orthodontic brackets were bonded on maxillary and mandibular teeth, as follows: 190 with Transbond XT composite (3M Unitek) (control) and 190 with Transbond Plus Color Change (3M Unitek) (experimental) in contralateral quadrants. The bonded brackets were light cured for 40 s, and initial alignment archwires were inserted. Bond failure rates were recorded over a six-month period. At the end of the evaluation, six bond failures occurred, three for each composite. Kaplan-Meyer method and log-rank test (Mantel-Cox) was used for statistical analysis, and no statistically significant difference was found between the materials (p=0.999). Both Transbond XT and Transbond Plus Color Change composites had low debonding rates over the study period.

Relation between Angle Class II malocclusion and deleterious oral habits

INTRODUCTION: Oral habits may interfere on the growth and development of the stomatognathic system and orofacial myofunctional conditions, producing changes in the position of teeth in their dental arches. OBJECTIVE: The purpose of this study was to verify the presence of deleterious oral habits in individuals with malocclusion and see if there is a predominance of Class II malocclusion in these individuals. METHODS: The records of 140 patients treated at the Clinic of Preventive Orthodontics FORP-USP who had already completed treatment were randomly selected and analyzed. Their ages ranged from 6 to 10 years and 11 months. Associations were made between the presence or absence of deleterious oral habits, type and number of habits found in each individual and the type of malocclusion according to Angle classification. The statistical analysis used was the Chi-square test with a significance level of 5%. History of deleterious oral habits was found in 67.1% of individuals. RESULTS: The Class I malocclusion was most frequent (82.9%), followed by Class II malocclusion (12.1%) and Class III (5%). CONCLUSION: There was a predominance of Class II malocclusion in individuals with a history of deleterious oral habits.

INTRODUÇÃO: hábitos bucais podem interferir no crescimento e desenvolvimento do sistema estomatognático e nas condições miofuncionais bucofaciais, acarretando alterações no posicionamento dos dentes nas respectivas arcadas dentárias. OBJETIVO: o objetivo dessa pesquisa foi verificar a presença de hábitos bucais deletérios em indivíduos portadores de má oclusão e observar se existe predominância de má oclusão Classe II de Angle nesses indivíduos. MÉTODOS: foram selecionadas, aleatoriamente, e analisadas 140 fichas de pacientes atendidos na Clínica de Ortodontia Preventiva da FORP-USP, que já haviam recebido alta no tratamento. A faixa etária variou dos 6 anos a 10 anos e 11 meses. Foram realizadas associações entre presença ou ausência de hábitos bucais deletérios, tipo e número de hábitos encontrados em cada indivíduo e o tipo de má oclusão, segundo a classificação de Angle. A análise estatística utilizada foi o teste qui-quadrado para independência, com nível de significância a 5%. História de hábitos bucais deletérios foi encontrada em 67,1% dos indivíduos. RESULTADOS: a má oclusão Classe I foi a mais encontrada (82,9%), seguida das más oclusões de Classe II (12,1%) e Classe III (5%). CONCLUSÃO: houve predomínio de má oclusão Classe II de Angle nos indivíduos com história de hábitos bucais deletérios.

Open bite: diagnosis, treatment and stability.

Open bite has fascinated Orthodontics due to the difficulties regarding its treatment and maintenance of results. This anomaly has distinct characteristics that, in addition to the complexity of multiple etiological factors, have aesthetic and functional consequences. Within this etiological context, several types of mechanics have been used in open bite treatment, such as palatal crib, orthopedic forces, occlusal adjustment, orthodontic camouflage with or without extraction, orthodontic intervention using mini-implants or mini-plates, and even orthognathic surgery. An accurate diagnosis and etiological determination are always the best guides to establish the objectives and the ideal treatment plan for such a malocclusion. This report describes two cases of open bite. At the end of the treatment, both patients had their canines and molars in Class I occlusion, normal overjet and overbite, and stability during the posttreatment period.

Clinical evaluation of the failure rate of metallic brackets bonded with orthodontic composites

The purpose of the present study was to evaluate in vivo the failure rate of metallic brackets bonded with two orthodontic composites. Nineteen patients with ages ranging from 10.5 to 38.7 years needing corrective orthodontic treatment were selected for study. The enamel surfaces from second premolars to second premolars were treated with Transbond Plus-Self Etching Primer (3M Unitek). Next, 380 orthodontic brackets were bonded on maxillary and mandibular teeth, as follows: 190 with Transbond XT composite (3M Unitek) (control) and 190 with Transbond Plus Color Change (3M Unitek) (experimental) in contralateral quadrants. The bonded brackets were light cured for 40 s, and initial alignment archwires were inserted. Bond failure rates were recorded over a six-month period. At the end of the evaluation, six bond failures occurred, three for each composite. Kaplan-Meyer method and log-rank test (Mantel-Cox) was used for statistical analysis, and no statistically significant difference was found between the materials (p=0.999). Both Transbond XT and Transbond Plus Color Change composites had low debonding rates over the study period.

O objetivo do presente estudo foi avaliar in vivo a taxa de falha de braquetes metálicos colados com dois compósitos ortodônticos. Dezenove pacientes com idades entre 10,5 e 38,7 anos, que necessitavam de tratamento ortodôntico corretivo, foram selecionados para estudo. As superfícies de esmalte de segundos pré-molares a segundos pré-molares foram tratadas com Transbond Plus Self-Etching Primer (3M Unitek). Em seguida, 380 bráquetes foram colados nos dentes superiores e inferiores, como segue: 190 com compósito Transbond XT (3M Unitek) (controle) e 190 com Transbond Plus Color Change (3M Unitek) (experimental), em quadrantes contralaterais. Os bráquetes colados foram fotopolimerizados por 40 s e arcos de alinhamento inicial foram inseridos. As taxas de insucesso na adesão foram registrados durante um período de seis meses. No final da avaliação, seis falhas de adesão ocorreram, três para cada composto. Para a análise estatística foram utilizados os testes de Kaplan-Meyer e log-rank (Mantel-Cox), e não houve diferença estatisticamente significante entre os materiais (p=0,999). Ambos compósitos, Transbond XT e Transbond Plus Color Change, tiveram baixas taxas de descolagem durante o período de estudo.

Open bite: diagnosis, treatment and stability

Open bite has fascinated Orthodontics due to the difficulties regarding its treatment and maintenance of results. This anomaly has distinct characteristics that, in addition to the complexity of multiple etiological factors, have aesthetic and functional consequences. Within this etiological context, several types of mechanics have been used in open bite treatment, such as palatal crib, orthopedic forces, occlusal adjustment, orthodontic camouflage with or without extraction, orthodontic intervention using mini-implants or mini-plates, and even orthognathic surgery. An accurate diagnosis and etiological determination are always the best guides to establish the objectives and the ideal treatment plan for such a malocclusion. This report describes two cases of open bite. At the end of the treatment, both patients had their canines and molars in Class I occlusion, normal overjet and overbite, and stability during the posttreatment period.

A mordida aberta tem fascinado enormemente a Ortodontia devido à dificuldade de tratamento e manutenção da estabilidade. É uma anomalia com características distintas que, além da complexidade dos múltiplos fatores etiológicos traz consequências estéticas e funcionais. De acordo com a etiologia, muitas mecânicas têm sido utilizadas no tratamento da mordida aberta, entre elas, grades palatinas, forças ortopédicas, ajuste oclusal, terapia de camuflagem com ou sem exodontias, intervenção ortodôntica com auxilio de mini-implantes ou mini-placas até a cirurgia ortognática. Considerando que um diagnóstico apropriado e a determinação da etiologia sempre serão os melhores guias para conduzir os objetivos e o plano de tratamento ideal desta maloclusão, dois casos de mordida aberta foram apresentados. Ao final do tratamento ambos os casos apresentaram oclusão de Classe I de caninos e molares, trespasse horizontal (overjet) e trespasse vertical (overbite) normais e na avaliação pós-contenção, mostraram estabilidade.

Corrosion in Haas expanders with and without use of an antimicrobial agent: an in situ study

OBJECTIVES: The purpose of this study was to evaluate in situ the occurrence of corrosion in the soldering point areas between the wire, silver brazing and band in Haas expanders. MATERIAL AND METHODS: Thirty-four 7-12-year-old patients who needed maxillary expansion with a Haas expander were randomly assigned to two groups of 17 individuals each, according to the oral hygiene protocol adopted during the orthodontic treatment: Group I (control), toothbrushing with a fluoride dentifrice and Group II (experimental), toothbrushing with the same dentifrice plus 0.12 percent chlorhexidine gluconate (Periogard®) mouthrinses twice a week. The appliances were removed after approximately 4 months. Fragments of the appliances containing a metallic band with a soldered wire were sectioned at random for examination by stereomicroscopy, scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Data were analyzed statistically by Fisher's test at 5 percent significance level. RESULTS: The analysis by optical microscopy revealed areas with color change suggestive of corrosion in the soldering point areas joining the band and the wire in all specimens of both groups, with no statistically significant difference between the groups (p=1). The peaks of chemical elements (Ni, Fe, Cr, O, C and P) revealed by EDS were also similar in both groups. CONCLUSION: Color changes and peaks of chemical elements suggestive of corrosion were observed in the soldering point areas between the wire, silver brazing and band in both control and experimental groups, which indicate that the 0.12 percent chlorhexidine gluconate mouthrinses did not influence the occurrence of corrosion in situ.

Evaluation of different LED light-curing devices for bonding metallic orthodontic brackets.

The aim of this study was to assess the influence of different light-emitting diodes (LED) light-curing devices for bonding orthodontic brackets, using the shear bond strength and analysis of adhesive remnant index (ARI). Crowns from 60 bovine incisors received brackets bonded with Transbond XT. Specimens were divided into 4 groups (n=15) according to the light-curing procedures: HL = control, halogen light; OR = Ortholux LED; UL = Ultraled XP, and RD = Radii LED. All light-curing procedures were performed for 40 s. Shear bond strength test was evaluated using an universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukey's test. The ARI scores were evaluated with a stereoscopic magnifying glass and analyzed statistically by Kruskal-Wallis test. A significance level of 5% was set for all analyses. Shear bond strength means in MPa and standard deviations were 9.82 (3.28), 12.70 (3.35), 9.04 (2.80) and 11.22 (2.36) for HL, OR, UL and RD, respectively. OR presented the highest shear bond strength mean value. HL differed significantly (p<0.05) from Groups OR and RD. However, these groups did not differ significantly from each other (p>0.05). Regarding the ARI scores, no statistically significant difference was observed (p>0.05) among the groups. In conclusion, Ortholux LED and Radii LED units provided the highest values of bracket adhesive strength.

Orthodontic-surgical treatment of Class III malocclusion with mandibular asymmetry.

Class III skeletal malocclusion may present several etiologies, among which maxillary deficiency is the most frequent. Bone discrepancy may have an unfavorable impact on esthetics, which is frequently aggravated by the presence of accentuated facial asymmetries. This type of malocclusion is usually treated with association of Orthodontics and orthognathic surgery for correction of occlusion and facial esthetics. This report presents the treatment of a patient aged 15 years and 1 month with Class III skeletal malocclusion, having narrow maxilla, posterior open bite on the left side, anterior crossbite and unilateral posterior crossbite, accentuated negative dentoalveolar discrepancy in the maxillary arch, and maxillary and mandibular midline shift. Clinical examination also revealed maxillary hypoplasia, increased lower one third of the face, concave bone and facial profiles and facial asymmetry with mandibular deviation to the left side. The treatment was performed in three phases: presurgical orthodontic preparation, orthognathic surgery and orthodontic finishing. In reviewing the patient's final records, the major goals set at the beginning of treatment were successfully achieved, providing the patient with adequate masticatory function and pleasant facial esthetics.