In vivo assessment of the corrosion of nickel-titanium orthodontic archwires by using scanning electron microscopy and atomic force microscopy.

This study was undertaken to assess in vivo the corrosion in two commercial nickel-titanium (NiTi) orthodontic archwires removed from the oral cavity of patients using fluoride mouthwashes. Five volunteers took part in this study on the corrosion behavior of two brands of NiTi archwires (3M and AO (brand of archwire)) during use of two mouthwashes with neutral sodium fluoride 1.1%, one with acidulated fluoride 1.1%, and one with placebo and a control group. Each patient used one mouthwash in three different periods of time for 1 min a day for 30 days. The archwires were assessed with scanning electron microscopy and atomic force microscopy for qualitative and quantitative analysis. The values obtained with atomic force microscopy (AFM) were submitted to normality test, two-way analysis of variance, and Tukey's test at a significance level of 5%. The AFM images showed a gradual qualitative increase in the roughness of both types of wire between the treatments: control < placebo < neutral fluoride < acidulated fluoride. The arithmetic average of the roughness and root mean square of the roughness were similar. As for 3M archwires, only the acidulated fluoride group differed statistically from the others. As for AO archwires, the control and placebo groups did not differ from each other, but differed from the other fluoride treatments. The group using neutral fluoride also differed significantly from the acidulated fluoride group. 3M archwires were not affected by daily oral challenges. AO archwires were not affected by daily oral challenges either; their association with fluoride, either neutral or acidulated, increased their roughness.

Estudo do crescimento da maxila em três planos cefalométricos, no crescimento puberal / Maxilary growth study in the three cephalometric dimensions during the puberal development

O presente estudo tem por finalidade contribuir com os estudos do crescimento maxilar nos planos vertical, sagital e transversal, interrelacionando-os, dando assim uma visão tridimensional ao crescimento da maxila. Foram estudados 27 indivíduos, sendo 15 do sexo feminino e 12 do sexo masculino, sendo que todos se encontravam inicialmente na fase de dentição mista, apresentavam uma oclusão satisfatória e não haviam sido submetidos a nenhum tipo de tratamento ortodôntico ou ortopédico prévio. As radiografias cefalométricas foram selecionadas de acordo com a maturação das vértebras cervicais, conforme os padrões estabelecidos por Hassel e Farman(1), em três fases: aceleração, transição e desaceleração, em que se mensurou 04 grandezas cefalométricas, que abrangeram os 03 planos espaciais, em cefalogramas obtidos em radiografias cefalométricas laterais e frontais. O crescimento foi estatisticamente significante em todas as grandezas estudadas, quando consideramos o crescimento na fase de aceleração até a fase de desaceleração. Porém, não foram encontradas diferenças estatísticas quando comparadas as fases: aceleração à transição e transição à desaceleração. Ao avaliarmos o crescimento maxilar, tendo como parâmetros os 03 planos espaciais, verificamos que ele é maior no sentido vertical, seguido pelo sagital e transversal, não se verificou diferenças entre os indivíduos do sexo masculino e do feminino.

This present study has as a goal contribute with maxillar growth studies on the vertical, sagittal and transversal planes, intertwining them, giving this way a tridimensional view of the mandible growth. Twenty-seven individuals were studied, fifteen females and twelve males. All of them were at the mixed dentition phase; they had a satisfactory occlusion and hadn’t been under any kind of previous orthopedic or orthodontic treatment. The cephalometric radiographs were selected according to the cervical vertebra maturation, in accordance with Hassel and Farman(1), in three phases: acceleration, transition, and deceleration on which four cephalometric greatnesses were measured that included the three spatial planes, in cephalograms obtained from lateral and front cephalometric radiographs. The growth was statistically significant in all the studied greatnesses, when considered the growth in the acceleration phase to the deceleration one. However, statistic differences were not found when acceleration was compared to transition and when transition was contrasted with deceleration. When we evaluated the maxillar growth, having as parameter the three spatial planes, we verified it is bigger vertically, sagittally and then transversally. It was not verified differences between sexes.

Avaliação das alterações do plano oclusal em telerradiografias em norma lateral no tratamento de más oclusões de Classe II, 1ª divisão, com Bionator de Balters, em pacientes retrovertidos, neutrovertidos e provertidos / Evaluation of occlusal plane changes in retroverted, neutroverted and proverted patients, with Class II, division 1, malocclusion treated with Balters' Bionator

OBJETIVO: este trabalho objetiva verificar as alterações do plano oclusal funcional de Ricketts, utilizando as variáveis que orientam este plano nas análises cefalométricas de Ricketts e Schawrz-Faltin, em pacientes portadores de má oclusão de Classe II de Angle, 1ª divisão, associada ao retrognatismo mandibular, cuja terapêutica indicada tenha sido a Bionatorterapia. METODOLOGIA: a amostra coletada neste estudo retrospectivo consta de 128 telerradiografias em norma lateral de 64 indivíduos retrovertidos, neutrovertidos e provertidos, de ambos os gêneros, no estágio de desenvolvimento da oclusão em fase mista ou permanente jovem. A faixa etária dos indivíduos selecionados para o estudo variou entre 7 anos e 1 mês a 13 anos e 2 meses no momento T1, sendo a média inicial de 10 anos de idade. A média de duração do tratamento foi de 19,7 meses. RESULTADOS E CONCLUSÃO: os resultados mostraram comportamentos distintos do plano oclusal, conforme o tipo facial retrovertido, neutrovertido ou provertido. O controle do plano oclusal na Bionatorterapia, pelo manejo do Bionator conforme o tipo facial de cada paciente, por meio de desgastes seletivos no acrílico e conseqüente erupção diferenciada dos dentes, pode influenciar favoravelmente o crescimento geral da face em cada tipo facial.

AIM: This work aims to verify the changes of Ricketts functional occlusal plane making use of variables which guide this same plane in the cephalometric analysis of Ricketts and Schwarz-Faltin among patients with Class II, division 1 malocclusion, associated to mandible retrognathism, whose therapy indicated has been Bionatortherapy. METHODS: The sample collected in this retrospective survey has 128 lateral cephalograms of 64 retroverted, neutroverted and proverted individuals, of both genders, at the stage of developing occlusion, either in mixed phase or permanent young. The age scale of individuals selected by the survey goes from 7 years and 1 month up to 13 years and 2 months in the T1 moment, with an initial mean age of 10 years. The mean length of time of treatment has been of 19.7 months. RESULTS AND COONCLUSION: The overall results have been submitted to statistical analysis and have shown that in the group of retroverted patients the occlusal plane goes round clockwise, in the group of neutroverted ones, the occlusal plane did not show up any relevant alterations between moments T1 and T2, and in the group of proverted patients the occlusal plane goes round counterclockwise. The occlusal plane control in the Bionatortherapy through the handle of the Bionator according to the facial type of each patient, through selective worn out acrylic and consequent diversified eruption of the teeth, can indeed cause favorable influence towards the overall growing up of the face in every facial type.