Efficiency of two protocols for maxillary molar intrusion with mini-implants

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 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.

Colagem indireta de bráquetes: apresentação de uma técnica passo a passo / Indirect bonding: a step-by-step technique

O emprego da colagem indireta tem se demonstrado um avanço na Ortodontia, uma vez que erros no posicionamento dos braquetes interferem diretamente no resultado final, bem como aumentam o tempo de tratamento. Esta técnica permite melhor visualização em todos os planos espaciais e, portanto, uma acurada padronização na fase de colagem. Apesar de todos os benefícios advindos do uso desta técnica, ainda há poucos ortodontistas adeptos da colagem indireta, talvez por falta de preparo técnico para uma execução adequada. Pelos motivos acima descritos, o objetivo deste manuscrito é apresentar, passo a passo, uma técnica de colagem indireta de braquetes na superfície vestibular dos dentes.

The use of indirect bonding technique has become an advance in Orthodontics, since bracket positioning errors directly affect the final result and increase treatment time. This technique allows better visualization in all spatial plans and, hence, accurate standardization in the bonding stage. Nevertheless, despite all benefits with using this technique, few orthodontists are still willing to perform indirect bonding, perhaps because of lack of technical training for proper development. For these reasons, the aim of this manuscript was to describe an indirect bracket bonding technique on the labial surfaces of the teeth, step-by-step.

Avaliação da inclinação vestibulolingual dos tubos de primeiros molares inferiores da prescrição MBT / Evaluation of the inclination buccolingual of the first molar tubes in MBT prescription

O presente estudo avaliou a precisão do torque de tubos metálicos de primeiros molares inferiores na prescrição MBT, em seis marcas comerciais: Unitek 3M, Abzil, American Orthodontics, Morelli, Aditek e TP Orthodontics. Empregaram-se 20 tubos de cada marca, totalizando 120 tubos. As imagens ampliadas do perfil dos tubos foram obtidas por um único operador, com a utilização de um microscópio eletrônico de varredura, e os ângulos foram mensurados empregando-se o software AutoCAD 2008 (32 Bit). O ângulo vestibulolingual foi determinado pelos ângulos APO (ângulo da parede oclusal) e APC (ângulo da parede cervical), e foram comparados aos valores de referência de -20º. Para a análise estatística, utilizou-se o teste paramétrico de análise de variância (Anova) e o teste de Tukey HSD, com intervalo de confiança de 95% e nível de significância de p < 0,05. Considerando-se os ângulos APO e APC, a marca Aditek foi a que mais se distanciou do valor de prescrição. As marcas Unitek 3M e TP Orthodontics foram as que mais se aproximaram dos valores de prescrição, respectivamente, para os ângulos APC e APO. Concluiu-se que existem variações na inclinação vestibulolingual dos tubos avaliados, podendo comprometer o posicionamento final dos dentes.

The aim of this current study was to evaluate the torque precision of the first lower molar metallic tubes according to the MBT prescription in six different commercial brands: Unitek 3M, Abzil, American Orthodontics, Morelli, Aditek e TP Orthodontics. Twenty tubes of each brand were used, adding up to 120 tubes. The enlarged images of the tube profiles were obtained by only one operator using an electronic scanning microscope, and the angles were measured by using the AutoCAD 2008 (32 bits) software. The buccolingual angle was determined by the angles APO (occlusal wall angle) and APC (cervical wall angle) and they were compared to the reference values of -20°. For statistical analysis, the parametric test of analysis of variance (Anova) and Tukey HSD test were used, with a confidence interval of 95% and significance level of p < 0.05. Considering the APO and APC angles, the Aditek brand was the one which got the farthest from the prescription value. Unitek 3M and TP Orthodontics were the nearest ones to the prescription values, respectively, for the APC and APO angles. It was concluded that there are variations in the buccolingual inclination of the tubes which were evaluated, compromising the final positioning of the teeth.

Halogen light versus LED for bracket bonding: shear bond strength

INTRODUCTION: LED light-curing devices seek to provide a cold light activator which allows protocols of material polymerization with shorter duration. OBJECTIVE: The present study aimed to evaluate the shear bond strength of bracket bonding using three types of light-curing devices: One with halogen light (Optilight Plus - Gnatus) and two with LEDs (Optilight CL - Gnatus and Elipar Freelight - 3M/ESPE). RESULTS: Comparing the results by analysis of variance, the Gnatus LED device showed an inferior statistical behavior in relation to other light sources, when activated by a short time. But, when it was used for 40 seconds, the polymerization results were consistent with the other evaluated sources. The device with the best average performance was the halogen light, followed by the 3M/ESPE LED. CONCLUSION: It was concluded that the LEDs may be indicated in orthodontic practice, as long as a protocol is used for the application of light with the activation time of 40 seconds.

INTRODUÇÃO: os aparelhos de fotopolimerização por LED buscam proporcionar uma luz ativadora fria, que possibilite protocolos de polimerização do material com menor tempo de duração. OBJETIVO: avaliar a resistência à tração da colagem de braquetes, utilizando três tipos de aparelhos fotoativadores: um de luz halógena (Optilight Plus - Gnatus) e outros dois de LED (Optilight CL - Gnatus; e Elipar Freelight - 3M/Espe). RESULTADOS: comparando os resultados por meio da análise de variância, o aparelho de LED Gnatus apresentou comportamento estatístico inferior em relação às outras fontes de luz, quando ativado por tempo reduzido. Já quando foi utilizado o tempo de 40 segundos, os resultados de polimerização foram compatíveis com as demais fontes avaliadas. O aparelho que apresentou melhor desempenho médio foi o de luz halógena, seguido pelo LED 3M/Espe. CONCLUSÃO: concluiu-se que os LEDs podem ser indicados na prática ortodôntica, uma vez que seja utilizado um protocolo de aplicação da luz com tempo de ativação de 40 segundos.

Mapping of proximal enamel thickness in permanent teeth

Aim: Knowledge of enamel thickness is relevant to perform stripping during orthodontic treatment. Thus, proximal enamel measurements of human permanent teeth were compared in this study. Methods: The measurements were previously obtained on cut sections of mandibular central (n = 30) and lateral (n = 30) incisors, canines (n = 20), first (n = 40) and second (n = 40) premolars; maxillary central (n = 20) and lateral (n = 20) incisors, canines (n = 20), first (n = 40) and second (n = 42) premolars. Comparisons between thicknesses by arch side and proximal surface were carried out using Student’s t-tests (á = 0.05). Teeth were compared according to the mesial and distal thicknesses by ANOVA and Tukey’s test. Results: No significant differences were found between right and left teeth. For the mesial surface, the mandibular second premolar presented the highest mean value (1.376 mm ± 0.198; p<0.001). The mandibular central incisor had the smallest thickness in relation to the other teeth (0.675 mm ± 0.144), although not significant compared with the mandibular lateral incisor and canine (0.734-0.781 mm). The mandibular second premolar also presented the higher distal thickness in relation to the others (1.450 mm ± 0.172), although not significant compared with the maxillary first premolar (1.322 mm ± 0.195). Mandibular incisors had the lowest means for distal thickness (0.872-0.879 mm), although not statistically different compared with maxillary incisors and mandibular canine (1.002-1.015 mm). Distal thickness was greater than mesial (p<0.001). Conclusions: Interproximal stripping should be less marked in incisors and mesial surfaces.

Avaliação da inclinação vestibulolingual dos tubos de segundos molares inferiores na prescrição MBT / Evaluation of the inclination bucco lingual of the second molar tubes on MBT prescription

O objetivo deste estudo foi avaliar a precisão do torque detubos metálicos na prescrição MBT, utilizando os segundos molaresinferiores como amostra representativa de quatro marcas comerciais.Quatro marcas que produzem tubos na prescrição foram selecionadas:Abzil, Aditek, American Orthodontics e 3M Unitek. Foram usados 20tubos de cada marca, constituindo 80 tubos. As imagens ampliadasdo perfil dos tubos foram obtidas por um único operador com autilização de um microscópio eletrônico de varredura, e os ângulosforam mensurados empregando-se o software AutoCAD 2008 (32Bit).Oângulo vestibulolingual foi estabelecido pela mensuração dos ângulosAPO (ângulo da parede oclusall e APC (ângulo da parede cervicall, eforam comparados aos valores de referência de -10°. Na avaliação dainclinação vestibulolingual por meio do ângulo APC, as marcas Abzil,American Orthodontics e 3M Unitek encontravam-se em conformidadecom a prescrição e eram semelhantes entre si. Para o ângulo APO,apenas a marca 3M Unitek ficou em conformidade com a prescrição,sem diferença estatística (p > 0,05).

The aim of the present study was to verify the torqueprecision of metallic tubes with MBT prescription using the lower secondmolars as the representa tive sample of four commercial brands. Fourtrademarks that provide MBT prescription tubes were selected: Abzil,Aditek, American Orthodontics, 3M Unitek. Twenty tubes each trademarkwere used, comprising 80 tubes. The enlarged images of the profile ofthe tubes were obtained by a single operator using a scanning electronmicroscope and the angles were measured using AutoCAD 2008 (32Bit).The bucco lingual angle was established by measuring the APO angles(angle of the oclusal wall) and were (angle of the cervical wall) and werecompared to reference values of -10°. In assessing the bucco lingualinclination angle by APC, the marks Abzil, American Orthodontics and3M Unitek were in accordance with the prescription and were similar. Forthe angle APO, only 3M Unitek was in accordance with the prescription,without statistical difference (p > 0.05).

Análise da relação carga/deflexão de fios ortodônticos retangulares de beta-titânio e aço inoxidável / Analysis of load/deflection rate of rectangular beta-titanium and stainless steel archwires

Visando comparar a relação carga/deflexão de fios ortodônticos retangulares de beta-titânio e aço inoxidável, de diferentes marcas, foram selecionados cinco arcos pré-contornados de cada uma das ligas das seguintes marcas: Abzil Lancer, Morelli, 3M Unitek e Ormco. A metodologia consistiu em posicionar os fios em um manequim ortodôntico com aparelho fixo colado e desprovido de incisivo central superior direito. O conjunto foi fixado a uma máquina universal de ensaios, Emic 10000, munida de uma ponteira de aço que transmitia cargas no centro do segmento do fio selecionado, correspondente ao incisivo extraído. Conforme o equipamento aplicava as forças, um software mensurava a deflexão do fio e gerava, automaticamente, gráficos e tabelas da relação carga/deflexão. Os fios de beta-titânio que apresentaram a menor relação carga/deflexão foram da marca Ormco, seguidos pela 3M Unitek e Abzil Lancer, que não apresentaram diferenças estatisticamente significantes. Analisando comparativamente os dois tipos de fios, notou-se que a liga de beta-titânio demonstrou uma relação carga/deflexão bem menor que a do aço inoxidável, independente da marca comercial do fio.

Comparing the load/deflection rate of beta-titanium and stainless steel rectangular orthodontic wire from different companies makers available in Brazil, they were selected by five archwires from each alloys of: Abzil Lancer, Morelli, 3M Unitek and Ormco. The methodology of replace the archwires in an orthodontic mannequin with fixed appliance and without right central incisor superior. The team was fixed in a Universal Testing Machine - Emic 10000 - that has a stainless pointer which takes the load in the center of the selected section of wire, in the area of the extracted incisor. While the equipment pressing the wire, a software was measuring the deflection of the wire and providing graphics and charts of load/deflection relate. The arches of beta-titanium alloy that had the lowest load/deflection rate was Ormco followed by 3M Unitek and Abzil Lancer, those didn't show significant statistic differences. Comparing both types of wires, concluded that the beta-titanium alloy showed a lower load/deflection rate than stainless steel, independent of brand wires.

Evaluation of proximal enamel thickness and crown measurements in maxillary first premolars

Estimating enamel thickness and planning the resultant optimal morphology of premolars aresubstantial steps before interproximal stripping. Aim: To analyze proximal enamel thickness andcrown measurements in maxillary premolars. Methods: The mesiodistal, buccolingual andcervico-occlusal measurements of 40 human maxillary first premolars (20 right, 20 left) wereregistered with a digital caliper. The teeth were embedded in acrylic resin and sectioned mesiodistallyat the level of the contact areas to obtain 1 mm-thick central sections. Enamel thickness on theproximal surfaces was measured using a perfilometer. Measurements were compared by theStudent’s t-test (α = 0.05). Results: The mean enamel thickness on the mesial surface was 1.22mm for the right (± 0.17) and left (± 0.18) sides. On the distal surface, the corresponding valueswere 1.28 mm (± 0.19) on the right side and 1.39 mm (± 0.17) on the left side. Mean values, inmillimeters, for the mesiodistal, buccolingual and cervico-occlusal measurements on both sidesranged from 7.03 (± 0.43) to 7.07 (± 0.48), 9.59 (± 0.48) to 9.65 (± 0.58) and 8.65 (± 0.66) to8.85 (± 0.65), respectively. There were no significant differences between right and left teeth.However, enamel thickness was significantly greater (p<0.05) on the distal surface. Conclusions:In maxillary first premolars, considering the greater thickness of distal enamel, interproximalstripping during orthodontic treatment may be more pronounced on this surface. The greatestmean value was observed for the buccolingual crown measurement, followed by the cervicoocclusaland mesiodistal dimensions.

Orthodontic retainers: analysis of prescriptions sent to laboratories

OBJECTIVE: To investigate the most commonly fabricated orthodontic retainers. METHODS: Information on the type and amount of maxillary and mandibular retainers produced in a three-month period was collected from six laboratories in the cities of São Paulo, Mauá and Guarulhos - Brazil. The retainers were grouped according to the total production. For the maxillary arch, the groups were: 1S - Begg retainer, 2S - Hawley retainer, 3S - transpalatal arch retainer, 4S - buccal resin-arch retainer and 5S - vacuum-formed retainer, Planas appliance, bonded lingual retainer and V-loop bonded lingual retainer. The groups relative to the mandibular arch were: 1I - 3-3 bonded lingual retainer (canine to canine), 2I - Hawley retainer and V-loop bonded lingual retainer, 3I - Begg retainer, 4I - buccal resin-arch retainer, vacuum-formed retainer and Planas appliance. The data were presented in box plots. Groups were compared using the Student's-t test with Bonferroni correction. RESULTS: The average of maxillary appliances fabricated ranged from 189.5 (1S) to 3.95 (5S). There were significant differences between groups 1S versus 5S and 2S versus 5S (p < 0.0001). Mean values for the mandibular retainers ranged from 55.3 (1I) to 4.2 (4I). Significant difference was observed between groups 2I and 4I (p < 0.0001). CONCLUSIONS: For the maxillary arch, the most requested retainers were Begg and Hawley retainers. Regarding the mandibular arch, bonded lingual retainers and Hawley retainer were the most frequent ones.

Características faciales y oclusales en niños con hábitos bucales / Occlusal and facial features in childrenwith oral habits

Fueron analizadas asociaciones entre tipos faciales, características oclusales y hábitos bucales. La muestra consistió de 1.923 escolares de 8 a 12 años (959 niñas, 964 niños) de Campo Grande, MS-Brasil. Comparaciones entre las características evaluadas según los hábitos fueron realizadas por testes de proporción e Chi-cuadrado (a = 5%). La prevalencia de hábitos fue de 37,4%. Hubo diferencia entre géneros, 55% (femenino) y 45% (masculino). Las mayores prevalencias fueron verificadas en el grupo de 8 años (32%) y en los colegios particulares (40,9%). Oñicofagia fue el más prevalente (71,7%), seguida por succión digital (9,7%) e interposición lingual (6,4%). En la mayoría de los grupos de hábitos, se observaron elevadas frecuencias de simetría facial (81-100%). En los que hacían succión digital, los tipos dolicofacial (46%) y mesofacial (43%) fueron significativamente más prevalentes, así como en los que presentaban interposición lingual, con respectivos porcentajes de 54% e 39%. De los portadores de hábitos, 76,9% tenían competencia labial. Las prevalencias de perfil convexo fueron significantemente más altas en los grupos de interposición lingual (85%), succión digital (83%) y oñicofagia (77%). En ellos, las prevalencias de overjet (52%) y trepase vertical (45%) normales fueron significativamente elevadas; sin embargo, en los alumnos con interposición lingual, la mordida abierta anterior fue la más prevalente (67%). La mordida cruzada posterior no fue asociada a los hábitos. A pesar del histórico de hábitos en 720 escolares, hubo asociación con simetría facial, tipos dolicofacial y mesofacial, competencia labial y perfil convexo. No se observó el predominio de maloclusiones.

Associations among facial types, occlusal features and oral habits were analyzed. The sample consisted of 1,923 students aged 8 to 12 years old (959 girls, 964 boys) from Campo Grande, MS-Brazil. Comparisons among the studied characteristics, which were evaluated according to the habits, were carried out using ratio and Chi-square tests (a = 5%). The prevalence of oral habits was 37.4%. There was a difference between genders: 55% for females and 45% for males. The highest prevalence was observed in the group of eight-year-olds (32%) and in private schools (40.9%). Nail biting was the most prevalent habit (71.7%), followed by digit-sucking (9.7%) and tongue thrusting (6.4%). In most of the habit groups, high frequencies of facial symmetry were observed (81-100%). In those who had digit-sucking habit, dolichofacial (46%) and mesofacial (43%) patterns were significantly more prevalent, as well as in those which presented tongue thrusting, with percentages of 54% and 39%, respectively. Of the habit holders, 76.9% presented lip competence. The prevalence of convex profile was significantly higher in the groups of tongue thrusting (85%), digit-sucking (83%) and nail biting (77%). In those students, frequencies of normal overjet (52%) and overbite (45%) were significantly great; but, in the group with tongue thrusting, anterior open bite was the most prevalent feature (67%). Posterior crossbite was not associated with the habits. Despite the history of habits in 720 students, there was an association with the facial symmetry, dolichofacial and mesofacial patterns, lip competence and convex profile. Malocclusions predominance was not observed.

Tratamiento no quirúrgico de las mordidas abierta esqueletales: utilización adecuada del anclaje con mini-implantes / Nonsurgical treatment of open bites skeletal: anchor with proper use mini-implants

En este estudio se estableció de acuerdo a diferentes investigaciones el método más eficaz y que nos produce menos recidiva en las mordidas abiertas anteriores con un patrón de crecimiento vertical. El método utilizado fue el de los mini-implantes. Es recomendable que las mordidas abiertas anteriores esqueléticas, en pacientes portadores de crecimiento vertical, sean corregidas preferencialmente por la intrusión de los dientes posteriores y no por la extrusión de los dientes anteriores, para evitar perjuicios estéticos. Los mini-implantes proporcionan anclaje absoluto en los molares y muestran mejores resultados. La recidiva de los dientes posteriores intruidos y la extrusión de los elementos anteriores son efectos indeseables generalmente relatados, con mayor frecuencia para otros tipos de aparatología como son magnetos, bite-blocks y aparatos removibles. Pero, ocurre con menor frecuencia en tratamientos con mini-implantes. Con el propósito de demostrar la indicación de estos dispositivos de anclaje absoluto, será relatado un caso clínico de un paciente con mordida cruzada posterior, mordida abierta esquelética y crecimiento vertical, de 17 años de edad, que no quería someterse a tratamiento quirúrgico, al cual se realizó disyunción con una aparatología de Haas, elásticas de 4 onzas de 3/16 para ayudar a realizar la rotación anti-horaria de la maxila y mini-implantes ortodóncicos auto-perforantes de titanio, con perfil transmucoso corto de 1mm de 1,6mm y una longitud de 8,0mm, tipo de cabezal de alta utilidad Pot™.

In this study the most effective method was established in agreement to different investigations and the one that produced less relapse to the anterior open bites with a pattern of vertical growth. The method used was the mini- implant. It is recommendable that skeletal anterior open bites, in patients with vertical growth pattern, are corrected preferentially by the intrusion of posterior teeth and not by the extrusion of anterior teeth to avoid aesthetic damages. The mini-implants provide absolute anchorage in molars and yield better results. Relapse of the anterior teeth with intrusion and the extrusion of the posterior teeth are generally undesirable effects related, with greater frequency for other types of orthodontic devices such as magnets, bite-blocks and removable devises. However, it happens with smaller frequency in treatments with mini-implant. To demonstrate the indication of these adjuncts for absolute anchorage, a clinical case report of a 17-year-old patient with posterior crossbite, skeletal anterior open bite and vertical growth pattern, who did not want to undergo surgical treatment, will be presented. Orthodontic treatment consisted of a disjunction with Haas expander, elastic of 4 ounces of 3/16 to help making the anti-clockwise rotation of the maxilla and self-drilling titanium orthodontic mini-implants, with short transmucosal profile of 1mm of 1,6mm and 8,0mm in length, type of head High Utility Pot™.

Are torque values of preadjusted brackets precise?

OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º) presented statistically significant difference from the proposed values (-7º). For the mandibular canines, American Orthodontics (-6.34º) and Ortho Organizers (-6.25º) presented statistically significant differences from the standards (-6º). Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment.

Uso de faceta estética provisória em tratamento ortodôntico com extração na técnica lingual / Use of temporary esthetic veneer during orthodontic treatment with extraction in lingual technique

Atualmente, muitos pacientes adultos procuram melhorar a aparência facialcorrigindo o posicionamento dos dentes com o uso de aparelho ortodôntico. Com o sorrisoconsiderado atraente, a pessoa melhora sua qualidade de vida e seu relacionamento social,pois a percepção de beleza influencia o desenvolvimento psicológico desde a infância até afase adulta do paciente. Por este motivo, a procura por aparelhos considerados estéticos temaumentado consideravelmente nos últimos anos, principalmente por meio da técnica lingual,citada por muitos como provedora de um aparelho invisível, devido ao posicionamento dosbráquetes pela face lingual dos dentes, e que tem se mostrado altamente eficiente e precisa.Este artigo teve como finalidade descrever o procedimento de colagem de facetas estéticastemporárias nos casos com extração, durante a fase de fechamento de espaços, proporcionandoconforto e estética agradável no decorrer do tratamento com o aparelho lingual.

Currently, many adult patients are seeking to improve facial appearance bycorrecting the positioning of the teeth with orthodontic appliances. With a smile consideredattractive, a person improves their quality of life and social relationships, since the perceptionof beauty influences the psychological development from childhood to adulthood of the patient.For this reason, the demand for orthodontic appliances considered esthetic has grownconsiderably in recent years, mainly for lingual technique, cited by many professionals asproviding an invisible appliance due to the positioning of the brackets on the lingual surfacesof the teeth, and which has proved to be an accurate and eflicient technique. This articleaims to describe the procedure for temporary bonding of veneers in cases of extractionduring the closing of spaces, providing comfort and pleasing esthetics during orthodontictreatment with lingual brackets.

Breastfeeding and non-nutritive sucking patterns related to the prevalence of anterior open bite in primary dentition

OBJECTIVE: Nutritional, immunological and psychological benefts of exclusive breastfeeding for the frst 6 months of life are unequivocally recognized. However, mothers should also be aware of the importance of breastfeeding for promoting adequate oral development. This study evaluated the association between breastfeeding and non-nutritive sucking patterns and the prevalence of anterior open bite in primary dentition. MATERIAL AND METHODS: Infant feeding and non-nutritive sucking were investigated in a 3-6 year-old sample of 1,377 children, from São Paulo city, Brazil. Children were grouped according to breastfeeding duration: G1 - non-breastfed, G2 - shorter than 6 months, G3 - interruption between 6 and 12 months, and G4 - longer than 12 months. Three calibrated dentists performed clinical examinations and classifed overbite into 3 categories: normal, anterior open bite and deep bite. Chi-square tests (p<0.05) with odds ratio (OR) calculation were used for intergroup comparisons. The impact of breastfeeding and non-nutritive sucking on the prevalence of anterior open bite was analyzed using binary logistic regression. RESULTS: The prevalence estimates of anterior open bite were: 31.9 percent (G1), 26.1 percent (G2), 22.1 percent (G3), and 6.2 percent (G4). G1 would have signifcantly more chances of having anterior open bite compared with G4; in the total sample (OR=7.1) and in the subgroup without history of non-nutritive sucking (OR=9.3). Prolonging breastfeeding for 12 months was associated with a 3.7 times lower chance of having anterior open bite. In each year of persistence with non-nutritive sucking habits, the chance of developing this malocclusion increased in 2.38 times. CONCLUSIONS: Breastfeeding and non-nutritive sucking durations demonstrated opposite effects on the prediction of anterior open bite. Non-breastfed children presented signifcantly greater chances of having anterior open bite compared with those who were breastfed for periods longer than 12 months, demonstrating the benefcial infuence of breastfeeding on dental occlusion.

Avaliação cefalométrica de componentes mandibulares em jovens portadores de má-oclusão classe II esquelética / Cephalometric evaluation mandibular components in young individuals with class II skeletal malocclusion

Este trabalho avalia o relacionamento ântero-posterior da mandíbula com a base do crânio (SNB, Nperp-P), o comprimento efetivo da mandíbula (Co-Gn)e a altura ântero-inferiorda face (Ena-Me), em jovens com rná-oclusão Classe II esquelética que apresentam ANB maior que 4,00 e Nperp-AP maior que 5,0 mm. A amostra foi composta por 80 telerradiografiascraniofaciais de perfil de 80 jovens brasileiros, leucodermas, divididos igualmente quanto ao gênero, com idade média de 12 anos e 11 meses. As medidas Nperp-P e SNB indicaram apresença de retrognatismo mandibular, com diferença estatisticamente significante entre o grupo avaliado e a norma populacional para as medidas Nperp-P para o gênero masculinoe Nperp-P e SNB para o feminino. A grandeza cefalométrica Co-Gn apresentou valor médio normal para o gênero feminino e normal ou aumentado para o gênero masculino e a medidaEna-Me apresentou valor aumentado para o gênero feminino e dentro da normalidade para o gênero masculino. Essas duas grandezas, apesar de alteradas, não apresentaram significância estatística. Concluiu-se que os componentes cefalométricos mandibulares foram determinantesna composição da má-oclusão Classe II esquelética.

In this study were eva/uated the effective length of mandible (Co-Gn), their antero-posterior relationship to the cranial base (SNB, Nperp-P), and the lower anterior facial height (Ena-Me), in young individuais withskeletal Class II malocclusion, that presented anANB higher than 4° and Nperp-AP higher than 5.0 mm . The study sample consisted of 80 cephalometric x-rays of white young individuais, equally divided according to the gender, with an age range of 12 to 13 years and 11 months. The measure Nperp-P and SNB, indicatedmandibular retrognatism, with statistically significant difference between evaluated group andpopulation norm for the measure Nperp-P for male gender and SNB and Nperp-P for female gender. The cephalometric measure Co-Gn presented normal value for female gender, and normal ar increased for male gender, and the cephalometric measure Ena-Me presented increased value for female gender and normal value for male gender. These two measure, even ir changed, don't presented stastistical significant. The results suggested that mandibular components were determinating on the composition of Class 11skeletal malocclusion.

Metallographic analysis of the internal microstructure of orthodontic mini-implants

Effective orthodontic anchorage may be obtained by miniimplants inserted into the maxillary bones. However, the risk of miniimplant failure is one of the most important issues, especially the rupture of its structure referred to as fracture, mainly due to metal deficiencies. This study analyzed the internal microstructure of orthodontic mini-implants, ascertaining the composition of the metal to detect possible discontinuities from the surface to the core of the screws. Eighteen samples of mini-implants, of 3 different brands, were obtained. The samples were cold-embedded in methyl methacrylate polymer, and were sectioned both longitudinally (3 samples of each brand) and transversely (the other 3 screws of each brand). After preparation, the samples were observed using a light microscope at up to 2,000 x magnification. The results showed that the mini-implants thus analyzed were composed of an Alpha-Beta globular phase of titanium alloy, patterns A1 and A9 (in accordance with the "Technical Committee of European Titanium Producers"). The miniimplants did not present any defects such as bubbles, imperfections or fissures, in either longitudinal or transverse sections, in their internal microstructure. All samples met the requirements of international norms. Orthodontists must be aware of the metal composition and internal microstructure of mini-implants, to decrease the risk of fractures.

Avaliação cefalométrica comparativa do índice de proporção entre as alturas faciais anterior e posterior, em pacientes não tratados ortodonticamente / Comparative cephalometric evaluation of the proportion index between anterior and posterior facial heights, in patients without orthodontic treatment

O índice da altura facial (IAF)exprime a rotação mandibular durante o tratamentoortodôntico e/ou crescimento craniofacial, de modo que seu controle ou modificação seja importante para o sucesso do tratamento ortodôntico. O objetivo neste trabalho foi estimaro IAF,segundo Horn, em pacientes portadores de má-oclusão, sem histórico de tratamento ortodôntico. Foram avaliadas telerradiografias em norma lateral de 50 pacientes, sendo 23do gênero masculino (na faixa etária dos oito anos e cinco meses aos 18 anos e quatro meses) e 27 do gênero feminino (na faixa etária dos oito anos e seis meses aos 22 anos e três meses). Um examinador calibrado realizou os traçados e as medições das alturas faciais anterior e posterior, para o cálculo do IAF.Foram determinadas as distribuições dos índices por gênero. Para a análise de diferenças dos índices médios quanto ao gênero foi aplicadoo teste t Student (a = 0,05). No grupo de pacientes do gênero masculino, a média do IAF foi de 0,6787 (dp = 0,0664); para pacientes do gênero feminino, a média foi de 0,6281 (dp = 0,0608). Os valores de referência para o IAF variaram de 0,65 a 0,75, indicando umcrescimento craniofacial harmonioso. Valores de IAF menores que 0,65 denotam um padrão facial hiperdivergente, com perfil convexo. Conclui-se que, para pacientes do gênero feminino, houve predomínio do padrão de crescimento hiperdivergente, com perfil facial convexo. Contudo, para o gênero masculino, o padrão de crescimento equilibrado, com perfil facial reto, foi observado com maior frequência.

The Facial Height Index (FHI)provides information on the mandibular rotationduring the orthodontic treatment stui/or craniofacial growth, hence, its control or modification is important for the orthodontic treatment be succeeded. The aim of this study was to estimate the FHI in patients with malocclusions, according to Horn, but without orthodontictreatment history. Lateral cephalometric radiographs of 50 patients, 23 males (aged between 8 years and 5 months to 18 years and 4 months) and 27 females (aged between 8 years and 6 months to 22 years and 3 months), were assessed. A calibrated examiner carried outthe tracings and the measurements of the anterior and posterior facial heights, in order to calculate the FHJ. The distributians ot the indexes were determined between genders. Thedifferences between the average indexes, according to gender, were analyzed using the student's t-test (a = 0.05). In male patients, the average FHI was 0.6787 (sd = 0.0664); for female patients, the average FHI was 0.6281 (sd = 0.0608). The reference FHI valuesvary trom 0.65 to 0.75, indicating a balanced;harmanious craniofacial growth. FHI values smaller than 0.65 are related to a facial hyperdivergent pattern, with convex profile. It maybe concluded that, for female patients, it was observed a hyperdivergent growth pattern, with convex facial profile. However, for the male ones, the growth pattern was balanced, with straight facial profile.

Avaliação da rotação do primeiro molar superior em más-oclusões classes I e II, divisão 1 / Evaluation of the first upper molar rotation in classes I and II, division 1 malocclusions

Este estudo teve como objetivo analisar e comparar a rotação do primeiro molarpermanente superior em pacientes portadores de más-oclusões de Classes I e II, Divisão 1 de Angle, além de verificar uma possível relação entre a rotação molar e a severidade da má -oclusão de Classe II. Para tanto, foram selecionados sistematicamente 60 pares de modelos, procedentes da Clinica de Ortodontia HM Dentistas Associados Ltda., de Porto Alegre, de indivíduos não tratados ortodonticamente, de ambos os gêneros, sendo 30 portadores demá-oclusão de Classe I, denominado grupo 1 e 30 de Classe II, Divisão 1, denominado grupo 2. O grupo 2 foi dividido em subgrupos, conforme o grau de severidade. Por meio de umaanálise dos modelos, que foram escaneados e avaliados em um programa de computador, foram mensurados três ângulos e uma medida linear. Os resultados foram determinados ecomparados estatisticamente para verificar a diferença da rotação do primeiro molar entre os grupos, assim como correlacionar a quantidade dessa rotação com a severidade da má-oclusãode Classe II. Concluiu-se que, na amostra analisada, houve rotação mesiopalatina do primeiro molar superior em ambas as más-oclusões e não ocorreu diferença estatisticamentesignificante entre os dois grupos. Também não se evidenciou relação entre a quantidade da rotação do molar e a severidade da má-oclusão de Classe II.

This article aims to analyze and compare the rotation of the first permanentmolar excess in samples of malocclusion of Classes I and II malocclusion, Division 1, Angle, besides see a possible link between the rotation moles and severity of the Class II. For both, was randomly selected 60 pairs of models, from the clinic of HM orthodontic dentistsassociated Ltda., Porto Alegre, untreated people of both sexes, with 30 malocclusion of Class I, called group 1; 30, Class II, Division 1, known as Group 2, which was divided into subgroups, as the degree of severity. The survey was developed by an analysis of patterns,which were scanned and evaluated through a computer program, for the measurement of three angles and a linear measure. The results were determined and compared betweengroups to try to link changes in the rotation of moles between the group of malocclusion group of Classes I and li, as well as to highlight the severity of the rotation of the upper first molar is related to the severity of Class li. It was concluded that there is mesiopalatal rotation of the upper first molar in both malocclusions, and there is no statistically significant difference between the two groups. Also there was no relationship evidenced between rotation and severity of Class II.

Estudo cefalométrico das alterações dos terços médio e inferior da face em pacientes com diferentes padrões respiratórios e faciais / Cephalometric study of the changes of the medium and lower thirds of the face in patients with different breathing and facial patterns

OBJETIVOS: avaliar a possível relação dos padrões respiratórios e dos tipos faciais com as grandezas da análise de Ricketts - CF-N.CF-A, Po-Or.ENA-ENP, CF-Go, CF-Xi.Po-Or, Xi-Pm, N-P.Go-M, A-NP, Po-Or.Na - e as grandezas da Nasofaringe e da Bucofaringe propostas por McNamara; dos tipos faciais com os padrões respiratórios e dos padrões respiratórios com as variáveis do Vert. MÉTODOS: a amostra consistiu de 88 telerradiografias em norma lateral de brasileiros leucodermas, dos gêneros masculino e feminino, entre 7 e 13 anos (média de idade 10,5 anos), sendo 45 respiradores bucais e 43 nasais. O método cefalométrico computadorizado abrangeu a análise das grandezas para determinação do tipo facial, segundo Ricketts (Índice Vert). Aplicou-se a avaliação do erro do método pela fórmula de Dahlberg (média = 0,52), seguida das avaliações estatísticas teste "t" de Student e Pearson product correlative coefficient test (p < 0,05). RESULTADOS E CONCLUSÕES: observou-se ausência de alterações estatisticamente significativas das variáveis quando relacionadas aos padrões respiratórios, e presença de diferenças estatisticamente significativas das variáveis Convexidade do ponto A, Altura posterior da face, Profundidade da maxila, Cone facial, Comprimento do corpo e Nasofaringe quando relacionadas aos tipos braqui e dolicofaciais. As variáveis Cone facial e Comprimento do corpo também apresentaram diferenças significativas entre os tipos braquifacial e mesofacial. A variável Cone facial apresentou diferenças significativas entre todos os tipos faciais; o tipo braquifacial apresentou correlação significativa (p = 0,011) com o padrão de respiração nasal e a variável Profundidade facial apresentou diferença estatisticamente significativa (p = 0,028) quando relacionada aos padrões respiratórios.

AIM: To assess the possible relation of respiratory patterns and facial types with linear and angular variables of the Ricketts analysis - CF-N.CF-A, Po-Or.ENA-ENP, CF-Go, CF-Xi.Po-Or, Xi-Pm, N-P.Go-M, A-NP, Po-Or.Na - and the Nasopharynx and Oropharynx linear variables proposed by McNamara; and of the facial types with the respiratory patterns, and the respiratory patterns with the Vert variables. METHODS: The sample consisted of 88 lateral teleradiographs of Brazilian leucoderm boys and girls, ranging from 7 to 12 years of age (mean age 10.5 years) of whom 45 were mouth-breathers and 43 nasal breathers. The computerized cephalometric method covered analysis of the variables to determine the facial type, according to Ricketts (Vert Index). After the measurements were taken, assessment of the method error by the Dahlberg formula was applied (mean = 0.52), followed by t Student and chi-square tests (p < 0.05) statistical assessments. RESULTS AND CONCLUSIONS: There were no statistically significant alterations in the variables when related to the respiratory patterns; there were statistically significant differences in the following variables: Convexity of point A, Posterior face height, Maxilla depth, Facial cone, Corpus length and Nasopharynx when related to the brachyfacial and dolicofacial types. The variables Facial cone and Corpus length also presented significant differences between the brachyfacial and mesofacial types, and the variable Facial cone presented significant differences among all the facial types; the brachyfacial type presented significant correlation (p = 0.011) with the nasal respiratory pattern; and Facial depth presented statistically significant difference (p = 0.028) when related to the respiratory patterns.