Abstract Background Genetic polymorphisms have been shown to influence several physiological traits, including dental and craniofacial characteristics. Understanding the clinical relevance of genetic polymorphisms in dental practice is crucial to personalize treatment plans and improve treatment outcomes. Objective to evaluate the association between dental age and genetic polymorphisms in genes encoding estrogen receptors alpha and beta (ESR1 and ESR2, respectively) in a sample of Brazilian children. Methodology This retrospective cross-sectional study was performed with children undergoing orthodontic treatment. Patients with syndromes, congenital anomalies, craniofacial deformities, under hormonal or systemic treatment, and with a previous history of facial trauma were excluded. Panoramic radiographs were used to assess dental age according to the Demirjian, Goldstein, and Tanner method. A delta [dental age-chronological age (DA-CA)] was obtained, which shows whether the patient tends to have a normal, delayed (negative values), or advanced (positive values) dental age. DNA isolated from buccal cells was used to genotype four genetic polymorphisms: rs9340799 (A>G) and rs2234693 (C>T), located in ESR1; and rs1256049 (C>T) and rs4986938 (C>T), located in ESR2. A statistical analysis was performed and values of p<0.05 indicated statistical difference. Results A total of 79 patients were included, 44 (55.70%) girls and 35 (44.30%) boys. The Demirjian, Goldstein, and Tanner method, in general, overestimated patients’ age by 0.75 years. There was no difference in the delta of dental age between the sexes (p>0.05). Genetic polymorphisms in ESR1 and ESR2 were not associated with dental age (p>0.05). Conclusion The studied genetic polymorphisms in ESR1 and ESR2 were not associated with dental age in Brazilian children.

Resumo Considerando que a fumaça de cigarro é um problema de saúde pública que está crescendo entre os adolescentes, o objetivo deste estudo foi investigar o impacto da fumaça de cigarro na sinalização osteogênica e osteoclastogênica da sutura palatina mediana de ratos. Foram utilizados ratos Wistar machos expostos (n=30) e não expostos à fumaça de cigarro (n=30). A exposição à fumaça de cigarro foi realizada duas vezes ao dia por 3 minutos, com um intervalo de 12 horas entre as exposições. Os animais foram mortos após o período experimental de 3, 7, 14 e 21 dias. Os tecidos coletados foram analisados em microscópico de luz e pelo RT-PCR em tempo real foi realizado para investigar a expressão gênica. s dados obtidos foram comparados usando o testes de Kruskal Wallis e Dunn (⍺ = 5%). Morfoligicamente, não houve mudança significativa na sutura palatina mediana nos ratos expostos ou não à fumaça de cigarro durante os tempo de 3, 7, 14 e 21 dias (p> 0.05). Por outro lado, a sinalização osteogênica esta aumentada nos animais expostos à fumaça e foi caracterizado por um aumento da produção de RANKL aos 3 e 14 dias (p <0.05), sem mudança na síntese da produção de RANK e osteoprotegerina (p> 0.05). Curiosamente, nos animais expostos, também foi observado um aumento precoce da síntese de osteocalcina, sialoproteína óssea e de osteopontina aos 3 dias de exposição, o que não foi mantido ao longo do tempo. A fumaça de cigarro modula a sinalização osteogênica e osteoclastogênica na sutura palatina mediana de ratos jovens, apesar de não tenha sido evidenciado alterações morfológicas.

Abstract Considering that smoking is a public health problem that has been growing among adolescents, the aim of this study was to investigate the impact of cigarette smoke on osteogenic and osteoclastogenic signaling in middle palatal suture of rats. Male Wistar rats exposed (n = 30) or not to cigarette smoke (n = 30) were used. Exposure to smoke was carried out for two daily periods of 3 minutes each, with an interval of 12 hours between exposures. After the experimental periods of 3, 7, 14 and 21 days, the animals were euthanized. The collected tissues were analyzed using light microscopy and real-time RT-PCR was performed to investigate gene expression. The data obtained were compared using the Kruskal Wallis and Dunn tests (⍺ = 5%). Morphologically, there were no significant changes in the middle palatal suture of rats exposed or not to cigarette smoke during 3, 7, 14 and 21 days (p> 0.05). On the other hand, osteoclastogenic signaling was increased in animals exposed to smoke and was characterized by a higher production of RANKL at 3 and 14 days (p <0.05), with no change in the synthesis of RANK and osteoprotegerin (p> 0.05). Interestingly, in the exposed animals, an early increase in the synthesis of osteocalcin, bone sialoprotein and osteopontin was also identified at 3 days of exposure (p <0.05), not sustained over time (p> 0.05). Cigarette smoke modulates osteogenic and osteoclastogenic signaling in the middle palatal suture of young rats, although morphological changes have not been evidenced.

Resumo O objetivo do estudo foi avaliar a resistência de união ao cisalhamento da colagem (RCC), o índice de remanescente de adesivo (IRA) e o modo de fratura de bráquetes cerâmicos com retenção química e mecânica colados com diferentes compositos e irradiados com laser de CO2. A hipótese nula testada foi que bráquetes colados com diferentes compósitos e irradiados com laser de CO2 apresentam valores semelhantes de RCC. Noventa pré-molares humanos foram divididos em 6 grupos (n=15): 2 controles e 4 experimentais que se diferenciaram pelo tipo de bráquete ceramic (Fascination and Mystique) e pelo compósito de fixação (Transbond XT e Z 250). Nos quatro grupos experimentais, os bráquetes foram irradiados com laser de CO2 com 10W por 3 segundos anteriormente ao teste de RCC. O IRA das superficies de esmalte foram avaliados após a descolagem e submetidos a análise em microscopia electrônica de varredura (MEV). Para análise estatística foram utilizados ANOVA e o teste de mann-Whitney. Os grupos laser mostraram valores de RCC menores que os grupos não irradiados (controles) (p<0.05). Os bráquetes com retenção mecânica (Mystique) mostraram alta RCC (p<0.05) e o compósito Z 250 obteve os mais baixos valores de RCC após irradiação com laser. Os grupos colados com o compósito Z 250 apresentaram os mais altos escores do IRA. O modo de fratura mais prevalente foi a adesiva. A hipótese nula foi rejeitada. O laser de CO2 foi eficaz para diminuir os valores de RCC e facilitou a descolagem dos bráquetes cerâmicos de retenção química e mecânica

Abstract This study evaluated shear bond strength (SBS), adhesive remnant index (ARI) and fracture mode of chemically and mechanically retained ceramic brackets bonded with different composite resins and irradiated with CO2 laser. The null hypothesis was that ceramic brackets bonded with different composite resins and irradiated with CO2 laser would have similar SBS values. Ninety human premolars were divided into four experimental groups according to the combination of type of composite resin (Transbond XT and Z 250) and type of ceramic bracket (Fascination and Mystique), and two control groups (n=15). In the four experimental groups, the brackets were irradiated with CO2 laser at 10 W for 3 seconds before SBS testing. Enamel surface ARI was calculated after debonding under electron microscopy scanning. ANOVA and the Mann-Whitney test were used for statistical analysis. The laser groups had lower SBS values than the non-irradiated groups (control) (p<0.05). The mechanically retained brackets (Mystique) had the higher (p<0.05) and Z250 had the lower SBS values after CO2 laser irradiation. The groups bonded with Z250 had the highest ARI. Adhesive fractures were the most prevalent. The null hypothesis was rejected. CO2 laser decreased SBS efficiently and facilitated debonding of mechanically and chemically retained ceramic brackets.

RESUMO Os problemas transversais devem ser priorizados no tratamento ortodôntico e corrigidos assim que diagnosticados, para restituir a correta relação transversal entre maxila e mandíbula e, consequentemente, restabelecer o crescimento maxilar normal. A correção pode ser realizada em nível esquelético, por meio da abertura da sutura palatina mediana (SPM), ou por expansão dentoalveolar. A opção de tratamento depende de alguns fatores como idade, sexo, grau de hipoplasia da maxila e a maturação da SPM. Assim, o objetivo do presente trabalho foi discutir as diferentes abordagens terapêuticas para correção da hipoplasia maxilar em pacientes com maturação esquelética avançada.

ABSTRACT Transverse deficiencies should be a priority in orthodontic treatment, and should be corrected as soon as diagnosed, to restore the correct transverse relationship between maxilla and mandible and, consequently, normal maxillary growth. Corrections may be performed at the skeletal level, by opening the midpalatal suture, or by dentoalveolar expansion. The choice of a treatment alternative depends on certain factors, such as age, sex, degree of maxillary hypoplasia and maturation of the midpalatal suture. Thus, the present study discusses different treatment approaches to correct maxillary hypoplasia in patients with advanced skeletal maturation.

Resumo Introdução A expansão rápida da maxila (RME) reduz o risco de desenvolvimento de distúrbios estruturais e funcionais no sistema estomatognático. Objetivo Analisar os efeitos desta intervenção como tratamento para a mordida cruzada posterior, relacionados à ocorrência de ruídos nas articulações temporomandibulares e à atividade eletromiográfica dos músculos masseter e temporal anterior. Material e método 13 meninas e 7 meninos, independentemente do tipo de maloclusão, com idade média de 9 anos (±3), foram tratadas com RME. Por meio de eletrovibratografia analisou-se ruídos nas articulações temporomandibulares, e de eletromiografia de superfície a atividade dos músculos mastigatórios antes (T0) e após 3 meses do final do tratamento proposto (T1). As comparações entre os lados afetado e não afetado pela mordida cruzada foram realizadas utilizando-se o teste de Mann-Withney. As comparações de antes e após o tratamento foram realizadas pelo teste de Wilcoxon (nível de significância: 5%). Resultado Não houve diferença significativa na eletrovibratografia entre os lados afetado e não afetado pela mordida cruzada, tanto em T0 como em T1 (p>0.05); do lado sem mordida cruzada observou-se diminuição do pico de amplitude dos ruídos articulares após a expansão rápida da maxila (p<0.05). Na análise da eletromiografia estática foram observadas diferenças inter-lados antes e após o tratamento, uma vez que a mastigação deliberada unilateral apresentou maior atividade de assimetria em T0 para ambos os lados, o que foi corrigido após o tratamento (p<0.05), melhorando a mastigação funcional padrão. Conclusão O tratamento proposto para mordida cruzada posterior funcional não levou à ocorrência de ruídos articulares e melhorou o padrão funcional da atividade eletromiográfica durante a mastigação ao final do tratamento.

Abstract Introduction The rapid maxillary expansion (RME) reduces the risk of developing structural and functional disorders in the stomatognathic system. Objective To examine the effects of the RME as a treatment for the posterior crossbite, related with the electromyographic activity of the masticatory muscles and the TMJ noises in a population of children. Material and method 13 girls and 7 boys, regardless of the type of malocclusion, with a mean age of 9 years old (± 3), were treated with RME. The electrovibratography analyzed the TMJ noise, and the electromyography analyzed the masticatory muscles before treatment (T0) and after three months of a short-term follow-up (T1). The comparisons of the affected and unaffected sides by the crossbite were performed using Mann-Whitney’s test, and to compare data before and after treatment the Wilcoxon’s test was used (level of significance: 5%). Result No significant differences were found in the parameters of joint noise in comparison to the sides affected and unaffected by the crossbite, in both T0 and T1 (p>0.05); only the side without the crossbite observed decrease in the peak amplitude of the joint noises after treatment. In the static electromyographic analysis, inter-side differences were observed before and after treatment, since the deliberate unilateral chewing showed greater asymmetry activity in T0 for both sides, which has been corrected after treatment, improving the functional chewing. Conclusion The proposed treatment did not lead to the occurrence of joint noises and improved the functional pattern of electromyographic activity during chewing at the end of treatment.

Abstract Objectives: Miniscrew has been frequently used, considering that anchorage control is a critical point in orthodontic treatment, and its failure, the main adverse problem. Using two groups of stable (successful) and unstable (failed) mini-implants, this in vivo study aimed to quantify proinflammatory cytokines IL-1 α, IL-6, IL-17, and TNF-α and osteoclastogenesis marker RANK, RANKL, and OPG in gingival tissue, using the real-time polymerase chain reaction technique. Methodology: Thirteen patients of both sexes (11-49 years old) under orthodontic treatment were selected, obtaining 11 successful and 7 failed mini-implants. The mini-implants were placed and removed by the same surgeon, in both jaws. The mean time of permanence in the mouth was 29.4 months for successful and 7.6 months for failed mini-implants. At removal time, peri-mini-implant gingival tissue samples were collected and processed for quantification of the proinflammatory cytokines and osteoclastogenesis markers. Nonparametric Wilcoxon rank-sum test considering the clusters and Kruskal-Wallis test were used for statistical analysis (α=0.05). Results: No significant difference (p>0.05) was observed between the groups for either quantification of cytokines or osteoclastogenesis markers, except for IL-6 (p<0.05). Conclusions: It may be concluded that the expression of IL-1α, IL-17, TNF-α, RANK, RANKL, and OPG in peri-implant gingival tissue were not determinant for mini-implant stability loss, but the higher IL-6 expression could be associated with mini-implant failure.

Abstract Objectives Enamel demineralization is among the main topics of interest in the orthodontic field. Self-ligating brackets have been regarded as advantageous in this aspect. The aim of this study was to evaluate the break homeostasis in the oral environment and the levels of microorganisms associated with dental caries among the different types of brackets. Material and Methods Twenty patients received two self-ligating brackets: In-Ovation®R, SmartClipTM, and one conventional GeminiTM. Saliva was collected before bonding (S0), 30 (S1) and 60 (S2) days after bonding. One sample of each bracket was removed at 30 and 60 days for the in situ analysis. Checkerboard DNA-DNA Hybridization was employed to evaluate the levels of microbial species as-sociated with dental caries. Data were evaluated by nonparametric Friedman and Wilcoxon tests at 5% significance level. Results The salivary levels of L. casei (p=0.033), S. sobrinus (p=0.011), and S. sanguinis (p=0.004) increased in S1. The in situ analyses showed alteration in S. mutans (p=0.047), whose highest levels were observed to the In-Ovation®R. Conclusions The orthodontic appliances break the salivary homeostasis of microorganisms involved in dental caries. The contamination pattern was different between self-ligating and conventional brackets. The In-Ovation®R presented worse performance considering the levels of cariogenic bacterial species.

RESUMO A transposição é considerada uma das anomalias dentárias mais difíceis de se administrar clinicamente. Vários fatores devem ser considerados para que a melhor decisão seja tomada. Neste artigo, o objetivo foi discutir as modalidades de tratamento da transposição dentária, suas vantagens e desvantagens, e apresentar um caso clínico de transposição entre canino e incisivo lateral na hemiarcada superior direita. A opção terapêutica de escolha foi a extração de um dos dentes transpostos, tendo-se a necessidade de uma abordagem multidisciplinar com a participação da Ortodontia, Dentística e Periodontia, a fim de que adequados resultados estéticos e funcionais fossem alcançados.

ABSTRACT Tooth transposition is one of the most difficult dental anomalies to treat in the dental clinic. Several factors must be taken into account with a view of making the best decision. The aim of this study was to discuss treatment modalities for tooth transposition, their advantages and disadvantages. Additionally, it aims at presenting a clinical case of transposition between canine and lateral incisor in the upper quadrant on the right side. The treatment of choice was extraction of one transposed tooth. A multidisciplinary approach involving Orthodontics, Cosmetic Dentistry, and Periodontology was necessary to allow proper esthetic and functional outcomes to be achieved.

Abstract Objectives Using two groups of mini-implants (successful and failed) the objectives of this in vivo study were: to evaluate the microbial contamination by the checkerboard DNA-DNA hybridization technique and to quantify the bacterial endotoxin by the limulus amebocyte lysate assay. Material and Methods The 15 successful and 10 failed mini-implants (1.6 mm diameter × 7.0 or 9.0 mm long), placed in the maxilla and/or mandible, were obtained from 15 patients undergoing orthodontic treatment. Data were analyzed statistically by the Wilcoxon rank-sum test using the SAS software (a=0.05). Results All 40 microbial species were detected in both groups of mini-implants, with different frequencies. No differences were observed between the groups with respect to microbial complexes (blue, purple, yellow, green, orange, red and other species) and endotoxin quantification (p>0.05). Conclusion Neither microbial contamination nor endotoxin quantification was determinant for the early loss of stability of the mini-implants.

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.

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.

Abstract Decalcification of enamel during fixed orthodontic appliance treatment remains a problem. White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. The use of fluoride-containing orthodontic materials has shown inconclusive results on their ability to reduce decalcification. The aims of this investigation were to compare the levels of Streptococcus mutans (SM) in saliva and biofilm adjacent to orthodontic brackets retained with a resin-modified glass ionomer cement (RMGIC) (Fuji ORTHO LC) and a light cured composite resin (Transbond XT), and to analyze the influence of topical application of the 1.23% acidulated phosphate fluoride (APF) on SM counts. In a parallel study design, two groups (n=14/15) were used with random allocation and high salivary SM counts before treatment. Biofilm was collected from areas adjacent to the brackets on teeth 13, 22, 33, and 41. Both saliva and biofilm were collected on the 7th, 21st, 35th, and 49th days after appliance placement. Topical fluoride application was carried out on the 35th day. Bonding with RMGIC did not alter SM counts in saliva or biofilm adjacent to the brackets. On the other hand, the biofilm adjacent to brackets retained with composite resin showed a significant increase in SM counts along the trial period. Topical application of 1.23% APF did not reduce salivary or biofilm SM counts regardless of the bonding material. In conclusion, fluoride topical application did not show efficacy in reducing SM. The use of RMGIC as bonding materials allowed a better control of SM cfu counts in dental biofilm hindering the significant increase of these microorganisms along the trial period, which was observed in the biofilm adjacent to the composite material.

Este estudo avaliou a eficácia do laser de CO2, associado ou não à aplicação de flúor na microdureza superficial do esmalte dentário adjacente a bráquetes ortodônticos. Foram selecionados 15 molares humanos, dos quais 30 fragmentos de esmalte com 4 mm2 foram obtidos. Os fragmentos foram incluídos em tubos de PVC, contendo resina acrílica, preparados usando lixas d'água e discos de feltro e alumina. Bráquetes ortodônticos cortados ao meio foram colados no esmalte e 3 leituras de microdureza foram realizadas na superfície adjacente: inicial, após desafio cariogênico e final. Os espécimes foram divididos em 3 grupos (n=10): Grupo C - Controle, Grupo L - irradiado com laser de CO2 e Grupo FL - aplicação tópica de flúor e irradiação com laser de CO2. Após leitura inicial, os espécimes foram colocados em solução desmineralizadora por 32 h e a segunda leitura foi realizada para verificar se desmineralização foi uniforme em todos os grupos. Após os tratamentos, os espécimes foram submetidos a ciclagem DES-RE durante 8 dias seguida da leitura da microdureza superficial final. Os dados foram analisdos estatisticamente utilizando ANOVA e o teste de Duncan (α=0,05). Na mensuração final o grupo FL obteve maior valor de microdureza que os grupos C e L (p<0,05). Os grupos L e FL foram estatisticamente superiores ao grupo C (p<0,05). A irradiação de laser de CO2 ao redor de bráquetes ortodônticos combinadas ou não à aplicação tópica de flúor foi eficaz no aumento da microdureza superficial do esmalte.

This study evaluated the effectiveness of carbon dioxide (CO2) laser combined or not with fluoride application on the surface microhardness of enamel adjacent to orthodontic brackets. Fifteen human molars were selected from which 30 enamel fragments measuring 4 mm2 were obtained. The fragments were embedded in PCV tubes with acrylic resin and prepared using water abrasive paper, felt disks and alumina. Orthodontic brackets cut in half were bonded to enamel and 3 microhardness readings were performed on the adjacent surface, as follows: initial, after cariogenic challenge and final. The specimens were divided into the following 3 groups (n=10): Group C: control, Group L: irradiated with CO2 laser, and Group FL: topical fluoride application and CO2 laser irradiation. After initial reading, the specimens were placed in a demineralizing solution for 32 h and the second reading was to verify if demineralization was uniform in all groups. After the treatments, the specimens were submitted to DES-RE cycling for 8 days followed by final surface microhardness reading. The data were analyzed statistically using ANOVA and Duncan test (α=0.05). At the final measurement Group FL obtained higher microhardness value than Groups C and L (p<0.05). Groups L and FL were statistically superior to Group C (p<0.05). Irradiation with CO2 laser around orthodontic brackets combined or not with topical fluoride application was effective to increase the surface microhardness of enamel.

INTRODUÇÃO: o presente trabalho apresenta um tratamento ortodôntico-cirúrgico realizado em paciente portadora de má oclusão de Classe III esquelética com crescimento mandibular, protrusão dentária superior e inferior, trespasse horizontal de -3,0mm, trespasse vertical de -1,0mm, ausência congênita do dente 22, dentes 13 e supranumerários inclusos, dente 12 com forma conoide e parcialmente irrompido em supraversão, retenção prolongada do dente 53, tendência ao crescimento vertical da face e assimetria facial. A discrepância na arcada superior era de -2,0mm, e na inferior era de -5,0mm. MÉTODOS: o tratamento ortodôntico pré-cirúrgico foi realizado com extrações dos dentes 35 e 45. Na arcada superior foram extraídos os dentes 53, 12 e supranumerário, para efetuar o tracionamento do canino incluso. Os espaços das extrações inferiores foram fechados com mesialização do segmento posterior. Após o alinhamento e nivelamento dos dentes, foram avaliados por meio de modelos de estudo o fechamento dos espaços das extrações e o posicionamento correto dos dentes nas bases ósseas, a intercuspidação correta das arcadas dentárias, com molares e caninos em Classe I de Angle, linhas medianas coincidentes, trespasse horizontal e trespasse vertical normais e torques ideais. A paciente foi encaminhada para realização de cirurgia ortognática e, em seguida, o tratamento ortodôntico pós-cirúrgico foi finalizado. RESULTADOS: a má oclusão de Classe III foi corrigida, estabelecendo padrões oclusais e faciais normais.

INTRODUCTION: Orthodontic-surgical treatment was performed in patient with skeletal Class III malocclusion due to exceeding mandibular growth. Patient also presented upper and lower dental protrusion, overjet of -3.0 mm, overbite of -1.0 mm, congenital absence of tooth #22, teeth #13 and supernumerary impaction, tooth #12 with conoid shape and partly erupted in supraversion, prolonged retention of tooth #53, tendency to vertical growth of the face and facial asymmetry. The discrepancy on the upper arch was -2.0 mm and -5.0 mm on the lower arch. METHODS: The pre-surgical orthodontic treatment was performed with extractions of the teeth #35 and #45. On the upper arch, teeth #53, #12 and supernumerary were extracted to accomplish the traction of the impacted canine. The spaces of the lower extractions were closed with mesialization of posterior segment. After aligning and leveling the teeth, extractions spaces closure and correct positioning of teeth on the bone bases, the correct intercuspation of the dental arch, with molars and canines in Angle's Class I, coincident midline, normal overjet and overbite and ideal torques, were evaluated through study models. The patient was submitted to orthognathic surgery and then the post-surgical orthodontic treatment was finished. RESULTS: The Class III malocclusion was treated establishing occlusal and facial normal standards.

OBJETIVO: avaliar o efeito da expansão rápida da maxila na dimensão da cavidade nasal e na morfologia facial através da rinometria acústica e rinomanometria computadorizada. MÉTODOS: foram avaliadas 29 crianças na fase de dentição mista, portadoras de respiração bucal e mordida cruzada posterior. A documentação ortodôntica e a avaliação otorrinolaringológica foram realizadas em três tempos - antes da expansão rápida da maxila, imediatamente após e 90 dias depois. RESULTADOS: a expansão promoveu um aumento na dimensão da cavidade nasal e na maxila transversalmente. Contudo, não houve diferenças significativas na área da mucosa nasal. A rinometria acústica mostrou que não houve diferenças na área de secção transversa ao nível da válvula e concha nasal inferior; entretanto, a rinomanometria mostrou diferenças estatisticamente significativas na resistência nasal, que diminuiu após a expansão rápida da maxila. CONCLUSÕES: a expansão maxilar aumenta a área óssea maxilar e nasal; contudo, esse aumento não foi suficiente para aumentar a área da mucosa e diminuir a resistência nasal. Importância: a expansão óssea nasal foi seguida por uma compensação da mucosa.

OBJECTIVE: To assess the effects of rapid maxillary expansion on facial morphology and on nasal cavity dimensions of mouth breathing children by acoustic rhinometry and computed rhinomanometry. METHODS: Cohort; 29 mouth breathing children with posterior crossbite were evaluated. Orthodontic and otorhinolaryngologic documentation were performed at three different times, i.e., before expansion, immediately after and 90 days following expansion. RESULTS: The expansion was accompanied by an increase of the maxillary and nasal bone transversal width. However, there were no significant differences in relation to mucosal area of the nose. Acoustic rhinometry showed no difference in the minimal cross-sectional area at the level of the valve and inferior turbinate between the periods analyzed, although rhinomanometry showed a statistically significant reduction in nasal resistance right after expansion, but were similar to pre-treatment values 90 days after expansion. CONCLUSION: The maxillary expansion increased the maxilla and nasal bony area, but was inefficient to increase the nasal mucosal area, and may lessen the nasal resistance, although there was no difference in nasal geometry. Significance: Nasal bony expansion is followed by a mucosal compensation.

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.

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.