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.

Evaluation of cervico-occlusal dimensions of maxillary and mandibular incisor brackets for lingual orthodontics.

AIM: The purpose of this study was to analyze the cervico-occlusal dimensions of brackets used in lingual orthodontics for maxillary and mandibular central and lateral incisors, to compare them with the numbers informed by the manufacturer. MATERIALS AND METHODS: The brackets were placed in a template and analyzed by scanning electron microscopy (SEM), evaluating the images with the aid of a software that allowed determination of reference points, tracing of lines on the bracket images and measurement of the distances. RESULTS: Brackets manufactured by Dm Ceosa Hiro, Tecnident PSWb and Dentaurum Magic did not present statistically significant differences between the mean values of slot heights and the values informed by manufacturers. Conversely, the brands Ormco 7th generation, Ormco STb, GAC Innovation L, ORJ-ORG, Tecnident, Ormco STb LSW and Adenta evolution STL exhibited statistically significant differences. CONCLUSION: In general, there was a deficiency in the standar-dization of cervico-occlusal measurements of slots of the brackets analyzed. CLINICAL SIGNIFICANCE: Manufacturers should be attentive to the quality control of their materials. Future studies will analyze the actual clinical influence of these findings on the orthodontic mechanics.

Sucking habits and anterior open bite among Venezuelan and Brazilian children

AIM: To investigate the associations between nutritive and non-nutritive sucking habits and the prevalence of anterior open bite, in children from Aragua-Venezuela and São Paulo-Brazil. METHODS: Seven calibrated examiners (κ = 0.89-1.0) performed clinical assessments in Venezuelans (N = 809) and Brazilians (N = 1,377) aged 3-6 years. Sucking habits were investigated using questionnaires answered by the mothers. Data were analyzed using logistic regression models (α = 0.05). RESULTS: Among 380 children with anterior open bite, 309 were Brazilians. Approximately 65% of Brazilians with pacifier-sucking habit lasting beyond 3 years of age had this malocclusion. Brazilians who prolonged pacifier and digit-sucking habits beyond 3 years of age have, respectively, 68.5 and 14.5 times more chances of presenting anterior open bite than children without sucking habits (p < 0.001). In Venezuelans with open bite, 37.7% had digit-sucking habits beyond 3 years of age, resulting in a high odds ratio (9.3; p < 0.001) when compared to children without this habit. No significant effect was found for bottle feeding. However, non-breastfed Venezuelan children or those breastfed for periods shorter than 6 months have a two-fold higher chance of presenting anterior open bite than children who were breastfed for longer periods, p = 0.008. CONCLUSIONS: Infant feeding had some effect on Venezuelan children, since insufficient breastfeeding was related to a higher prevalence of anterior open bite. Pacifier-sucking was more prevalent in Brazilians, corresponding to pronounced chances (8-68 times greater) of diagnosing anterior open bite in pacifier users compared to non-users. Among Venezuelans, on the other hand, digit-sucking effect surpassed that of pacifier use and was associated with far higher chances (6-9 times) for this malocclusion...

Avaliação do perfil de braquetes metálicos da técnica ortodôntica lingual / Evaluation of the metal brackets of the lingual orthodontic technique profile

Atualmente, a Ortodontia lingual é a melhor alternativa de tratamento ortodôntico estético. Com isso, é crescente a preocupação em desenvolver braquetes linguais menores, mais individualizados, para aumentar o conforto oral e minimizar os efeitos indesejáveis na fala, na mastigação e na higienização do paciente. O objetivo desta pesquisa foi estudar a altura do perfil dos braquetes linguais presentes no mercado brasileiro. Para isso, foram avaliados 112 braquetes, das marcas comerciais mais acessíveis ao ortodontista brasileiro, entre nacionais e importadas. Para se proceder a análise, foram confeccionados 24 corpos de prova, com cinco braquetes colados em cada um. Obtiveram-se então imagens dos braquetes em um microscópio eletrônico de varredura, com um aumento de 45 vezes, de toda a extensão do braquete. As dimensões foram mensuradas e, partir dos resultados, verificou-se que dentro de uma mesma marca comercial não houve diferenças entre o perfil dos braquetes. Entretanto, quando houve a comparação entre as marcas, notou-se diferenças estatisticamente significantes entre o perfil das diversas marcas, o que permite ao ortodontista optar pelo acessório com perfil mais adequado às suas necessidades clínicas...

Currently lingual orthodontics is the best alternative for aesthetic orthodontic treatment. Thus, there is a growing concern to develop more individualized, lower lingual brackets to increase oral comfort and minimize undesirable effects on speech, chewing and cleaning the patient. The objective of this research was to evaluate the profile of lingual brackets present in the Brazilian market. For this 112 brackets were evaluated, the most accessible to the Brazilian orthodontist between domestic and imported trademarks. To conduct the analysis, 24 specimens were fabricated with 5 brackets bonded to each. Then obtained images of the brackets in a Scanning Electron Microscope with an increase of 45 times, the entire length of the bracket. The dimensions were measured and from the results, it was found that within a trademark there were no differences between the profile of the brackets. However, when there was a comparison between the marks was noticed statistically significant differences between the profile of the various brands, which allows the orthodontist to choose the accessories that best suits your clinical needs profile...

Estudo da discrepância osteodentária, pré e pós-tratamento ortodôntico, em más-oclusões de Classe I / Study of bone and tooth discrepancy before and after orthodontic treatment in Class I malocclusions

Esta pesquisa teve como objetivo analisar a discrepância osteodentária nas fases pré e pós-tratamento ortodôntico, em casos de más-oclusões de Classe I. Foram selecionados modelos de estudo em gesso de 25 pacientes (19 do sexo feminino e seis do sexo masculino) com médias de idade de 14,2 anos ± 3,2 ao início do tratamento e 17,6 anos ± 2,7 ao final. Todos tiveram más-oclusões de Classe I tratadas sem extrações dentárias. Um examinador calibrado realizou mensurações das larguras mesiodistais dos dentes e do perímetro do arco mandibular com um paquímetro digital Mitutoyo, com precisão de 0,01 mm, por duas vezes. Foram calculados os valores mínimo e máximo, bem como medianas, médias e desvios-padrão das discrepâncias osteodentárias pré e pós-tratamento ortodôntico. A reprodutibilidade das mensurações foi avaliada pelo teste t de student pareado (α = 0,05). Não houve diferenças estatísticas entre a primeira e a segunda mensuração, indicando boa reprodutibilidade. Em, pelo menos, 60% dos casos ocorreu redução da discrepância de modelo para valores clinicamente aceitáveis. Na fase inicial do tratamento, 50% da amostra apresentavam falta de espaço no arco dentário mandibular (mediana: -0,54 mm). A discrepância média também foi negativa (média: -0,16 mm ± 3,36). Ao final, mediana (0,63 mm) e média (0,65 mm ± 0,85) foram positivas e mais próximas, denotando acréscimo aceitável de espaço na maioria dos arcos dentários. Concluiu-se que o tratamento ortodôntico melhorou as condições de espaço nos arcos dentários mandibulares, reduzindo discrepâncias negativas de até 4 mm e discrepâncias positivas de até 9 mm, sem a necessidade de exodontias.

The aim of this study was to analyze pre- and post-treatment bone and tooth discrepancy in Class l malocclusions. Study casts from 25 patients (19 females, six males) with mean ages of 14.2 years ± 3.2 at the beginning of treatment and 17.6 years ± 2.7 at the end were selected. All of them had their malocclusions treated without tooth extractions. One calibrated examiner performed measurements of mesiodistal tooth width and mandibular arch perimeter using a digital caliper (Mitutoyo) accurate to 0.01 mm, twice. Bone and tooth discrepancy minimum and maximum values, as well as medians, means and standard deviations, were calculated from pre- and post-treatment casts. Measurements reproducibility was assessed using paired student’s-t test (α = 0.05). No statistical differences were found between first and second measurement, indicating good reproducibility. In at least 60% of cases bone and tooth discrepancy was reduced to clinically suitable values. In the pre-treatment phase, 50% of the sample had lack of space in the mandibular dental arch (median: -0.54 mm). The average discrepancy was also negative (mean -0.16 mm ± 3.36). In the post-treatment phase, median (0.63 mm) and mean (0.65 mm ± 0.85) values were positive and closer, pointing out an acceptable space gain in most dental arches. It may be concluded that orthodontic treatment improved space conditions in the mandibular dental arches, by decreasing negative and positive discrepancies of up to 4 mm and 9 mm, respectively, without the need for extractions.

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.

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.

Associação entre flexão da base do crânio e prognatismo maxilar em dois grupos raciais / Association between cranial base flexure and maxilllary prognathism in two racial groups

A associação entre flexão da base do crânio e prognatismomaxilar foi avaliada em dois grupos raciais brasileiros. A amostraconsistiu de 240 crânios macerados de leucodermas (n = 120) emelanodermas (n = 120) de ambos os gêneros. A flexão da base docrânio e o prognatismo maxilar foram investigados por meio da estimativados valores médios dos ângulos NHBa e NABa, respectivamente.Aplicou-se o teste t Student (a = 0,05) nas comparações dos valoresmédios do ângulo NHBa, entre grupos raciais e gêneros. A associaçãoentre os ângulos NHBa e NABa foi avaliada pela análise de correlaçãolinear. Os valores médios do ângulo NHBa apresentaram-se maiores emmelanodermas (femininos = 183° e masculinos = 181,7°), comparadosaos leucodermas (femininos = 180,7° e masculinos = 178,4°), p <0,01. A maioria das correlações entre os ângulos NHBa e NABa não foisignificativa. Houve diferenças raciais e dimorfismo sexual no que serefere à flexão da base do crânio. As correlações entre as grandezasangulares que medem a flexão da base do crânio e o prognatismo maxilarnão foram significativas, à exceção dos melanodermas femininos.Sugere-se uma tendência para a elevação do prognatismo maxilar àmedida que aumenta a inflexão da base do crânio no referido grupo.

The association between cranial base flexure and maxillaryprognathism was assessed in two Brazilian racial groups. Thesample comprised 240 dry skulls of white (n = 120) and black (n = 120)Brazilians, of both genders. Cranial base flexure and maxillary prognathismwere investigated by estimating the mean values of the NHBa andNABa angles, respectively. TheNHBa angle mean values were comparedbetween racial groups and genders using the student t-test (a = 0.05).The association between NHBa and NABa angles was assessed by thelinear correlation analysis. NHBa angle mean values were higher in blackindividuais (females = 183° and males = 181.7"), compared with whiteindividuais (females = 180.;0 and males = 178.4°), p < 0.01. Most ofthe correlations between NHBa and NABa angles were not significant.Concerning the cranial base flexure, there were racial differences andsexual dimorphism. The correlations between the angular variables usedto estimate cranial base flexure and maxillary prognathism were notsignificant, except for black females. It may be suggested that a trendto increased maxillary prognathism is related to the enlargement of thecranial base flexure angle in the above-mentioned group.

Crown dimensions and proximal enamel thickness of mandibular second bicuspids.

To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left). Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5%). The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47) and 7.70 mm (± 0.51), respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75) on the right to 8.38 mm (± 0.85) on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70) on the right and 8.65 mm (± 0.54) on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22) to 1.40 mm (± 0.17), on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21) and 1.46 mm (± 0.12). No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.

Crown dimensions and proximal enamel thickness of mandibular second bicuspids

To achieve proper recontouring of anterior and posterior teeth, to obtain optimal morphology during enamel stripping, it is important to be aware of dental anatomy. This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left). Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5 percent). The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47) and 7.70 mm (± 0.51), respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75) on the right to 8.38 mm (± 0.85) on the left teeth. The mean values for the buccolingual dimension were 8.67 mm (± 0.70) on the right and 8.65 mm (± 0.54) on the left teeth. The mean enamel thickness on the mesial surfaces ranged from 1.35 mm (± 0.22) to 1.40 mm (± 0.17), on the left and right sides, respectively. On the distal surfaces, the corresponding values were 1.44 mm (± 0.21) and 1.46 mm (± 0.12). No significant differences were found between measurements for right and left teeth. However, enamel thickness was significantly greater on the distal surfaces, compared with the mesial surfaces.

Mesiodistal width and proximal enamel thickness of maxillary first bicuspids.

This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left), selected from white patients (mean age: 23.7 +/- 4.2 years), who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the buccal side, to obtain 0.6-mm central sections. The mesiodistal crown width and proximal enamel thickness were measured using a stereoscopic microscope connected to a computer. Measurements for right and left teeth, as well as the mesial and distal enamel thicknesses in the total sample, were compared by the Wilcoxon test (alpha = 0.05). The mesiodistal crown width mean values found were 7.51 mm (+/- 0.54) on the right side and 7.53 mm (+/- 0.35) on the left side. The mean enamel thickness on the distal surfaces for both sides was 1.29 mm (right: s.d. = 0.12 and left: s.d. = 0.18). The mean values for the mesial surfaces were 1.08 mm (+/- 0.14) and 1.19 mm (+/- 0.25), on the right and the left sides, respectively. No significant differences were found between the crown measurements and enamel thicknesses on the left and right sides. However, enamel thickness was significantly greater on the distal surfaces. Reliable measurements of enamel thickness are useful to guide stripping, which may be an attractive alternative to tooth extraction because it allows the transverse arch dimension to be maintained.

Mesiodistal width and proximal enamel thickness of maxillary first bicuspids

This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left), selected from white patients (mean age: 23.7 ± 4.2 years), who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the buccal side, to obtain 0.6-mm central sections. The mesiodistal crown width and proximal enamel thickness were measured using a stereoscopic microscope connected to a computer. Measurements for right and left teeth, as well as the mesial and distal enamel thicknesses in the total sample, were compared by the Wilcoxon test (α = 0.05). The mesiodistal crown width mean values found were 7.51 mm (± 0.54) on the right side and 7.53 mm (± 0.35) on the left side. The mean enamel thickness on the distal surfaces for both sides was 1.29 mm (right: s.d. = 0.12 and left: s.d. = 0.18). The mean values for the mesial surfaces were 1.08 mm (± 0.14) and 1.19 mm (± 0.25), on the right and the left sides, respectively. No significant differences were found between the crown measurements and enamel thicknesses on the left and right sides. However, enamel thickness was significantly greater on the distal surfaces. Reliable measurements of enamel thickness are useful to guide stripping, which may be an attractive alternative to tooth extraction because it allows the transverse arch dimension to be maintained.

Estimativa radiográfica da espessura do esmalte proximal em primeiros pré-molares superiores / Radiographic estimate of approximal enamel thickness in maxillary first premolars

A estimativa radiográfica da espessura do esmalte é relevante para aplicação das técnicas de desgaste proximal no tratamento ortodôntico, visando evitar danos aos tecidos adjacentes. Esta pesquisa teve por objetivo validar estimativas da espessura doesmalte proximal, executadas por meio de radiografias convencionais, com base nos dados das análises de secções dentárias. Foram avaliadas imagens radiográficas das faces proximais de 40 dentes primeiros pré-molares superiores humanos hígidos extraídos. Dois examinadores em consenso realizaram as mensurações radiográficas com auxílio de paquímetro digital,sobre negatoscópio, em sala com baixa intensidade de luz. Para validação, secções longitudinais centrais dos dentes (1 mm) foram analisadas ao perfilômetro, instrumento de precisão milesima!. As análises comparativas foram viabilizadas pelo teste de Mann-Whitney (a = 5%). As médias de espessura do esmalte, nas imagens radiográficas das faces mesial e distal,foram equivalentes a ] ,28 mm (± 0,15) e ] ,27 mm (± 0,12), respectivamente. Por outro lado, ao perfilômetro, os valores foram: 1,22 mm (± 0,17) para a face mesial e ] ,32 mm (± 0,19) para a dista!. Não houve diferenças significantes entre dentesdos lados direito e esquerdo, para os dois métodos. Ao perfilômetro, a espessura média do esmalte foi maior na face distal(p < 0,0 I). Houve diferença significativa entre métodos para a espessura do esmalte na face distal; mais elevada ao perfilômetro(p < 0,05). A espessura do esmalte foi subestimada por mensurações radiográficas nas faces distais de primeiros pré-molares superiores. Contudo, sugere-se que a subestimativa radiográfica observada neste estudo não apresenta significância clínica.

Radiographic estimation of approximal enamel thickness is important for application of stripping techniques, during orthodontic treatment, to avoid damaging the adjacent tissues. The aim of this study was to validate the estimates of approximal enamelthickness, carried out using conventional radiographs, based on data from histological analysis of teeth sections. Radiographic images ofthe approximal surfaces of 40 extracted human maxillary first premolars were assessed. Measurements were performedby two examiners in consensus using digital caliper and viewing box, under subdued lighting in sec/uded room. For validation, longitudinal sections (1 mm), at the tooth center; were analyzed using a perfilometer; a higb precision measuring device. Data werecompared by Mann-Whitney test (a = 5%). Mean enamel thicknesses, in radiographic images ofthe mesial and distal surfaces, were equivalent to 1.28 mm (± 0.15) and 1.27 mm (± 0.12), respectively. However, by perfilometer; the values were: 1.22 mm (±0.17)for the mesial surface and 1.32 mm (± 0.19) for the distal one. No significant difJerences werefound between right and lefl teeth, by the studied methods. By perfilometer; the distal mean enamel thickness was greater compared with that for the mesial surface (p < 0.01). Considering the distal surface, there was significant difference between methods; mean enamel thickness washigher by perfilo meter (p < 0.05). Enamel thickness was underestimated by radiographic measurements in the distal surfaces of maxillaryfirst premolars. Nevertheless, it may be suggested that the radiographic underestimation observed in this study does nothave c1inicalsignificance.

Comparative study of dental arch width in plaster models, photocopies and digitized images.

The aim of this study was to comparatively assess dental arch width, in the canine and molar regions, by means of direct measurements from plaster models, photocopies and digitized images of the models. The sample consisted of 130 pairs of plaster models, photocopies and digitized images of the models of white patients (n = 65), both genders, with Class I and Class II Division 1 malocclusions, treated by standard Edgewise mechanics and extraction of the four first premolars. Maxillary and mandibular intercanine and intermolar widths were measured by a calibrated examiner, prior to and after orthodontic treatment, using the three modes of reproduction of the dental arches. Dispersion of the data relative to pre- and posttreatment intra-arch linear measurements (mm) was represented as box plots. The three measuring methods were compared by one-way ANOVA for repeated measurements (alpha = 0.05). Initial / final mean values varied as follows: 33.94 to 34.29 mm / 34.49 to 34.66 mm (maxillary intercanine width); 26.23 to 26.26 mm / 26.77 to 26.84 mm (mandibular intercanine width); 49.55 to 49.66 mm / 47.28 to 47.45 mm (maxillary intermolar width) and 43.28 to 43.41 mm / 40.29 to 40.46 mm (mandibular intermolar width). There were no statistically significant differences between mean dental arch widths estimated by the three studied methods, prior to and after orthodontic treatment. It may be concluded that photocopies and digitized images of the plaster models provided reliable reproductions of the dental arches for obtaining transversal intra-arch measurements.

Comparative study of dental arch width in plaster models, photocopies and digitized images

The aim of this study was to comparatively assess dental arch width, in the canine and molar regions, by means of direct measurements from plaster models, photocopies and digitized images of the models. The sample consisted of 130 pairs of plaster models, photocopies and digitized images of the models of white patients (n = 65), both genders, with Class I and Class II Division 1 malocclusions, treated by standard Edgewise mechanics and extraction of the four first premolars. Maxillary and mandibular intercanine and intermolar widths were measured by a calibrated examiner, prior to and after orthodontic treatment, using the three modes of reproduction of the dental arches. Dispersion of the data relative to pre- and posttreatment intra-arch linear measurements (mm) was represented as box plots. The three measuring methods were compared by one-way ANOVA for repeated measurements (á = 0.05). Initial / final mean values varied as follows: 33.94 to 34.29 mm / 34.49 to 34.66 mm (maxillary intercanine width); 26.23 to 26.26 mm / 26.77 to 26.84 mm (mandibular intercanine width); 49.55 to 49.66 mm / 47.28 to 47.45 mm (maxillary intermolar width) and 43.28 to 43.41 mm / 40.29 to 40.46 mm (mandibular intermolar width). There were no statistically significant differences between mean dental arch widths estimated by the three studied methods, prior to and after orthodontic treatment. It may be concluded that photocopies and digitized images of the plaster models provided reliable reproductions of the dental arches for obtaining transversal intra-arch measurements.

Associação entre o hábito de sucção de chupeta, a relação terminal dos segundos molares decíduos e a sobressaliência / Association between pacifier use terminal relationship of the primary second molars and overjet

O objetivo deste trabalho foi avaliar os relacionamentos ântero-posteriores dos segundos molares e incisivos decíduos em crianças com hábito de sucção de chupeta. Três cirurgiões-dentistas examinaram 561 crianças na faixa etária dos 3 aos 6 anos para a classificação das relações dos segundos molares e a mensuração da sobressaliência. Das 336 crianças incluídas na amostra, 246 apresentavam histórico de sucção de chupeta e foram distribuídas em três grupos experimentais de acordo com a persistência do hábito: até os 2 anos de idade, dos 2 aos 4 anos e dos 4 aos 6 anos de idade. As 90 crianças com ausência de hábitos de sucção formaram o grupo controle. Os grupos foram comparados, segundo as características oclusais avaliadas, por meio do teste Qui-Quadrado (p < 0,05). A prevalência de degrau mesial foi significativamente mais baixa nas crianças que mantiveram o hábito de sucção dos 4 aos 6 anos de idade. Não houve diferenças significativas entre os grupos para os valores de prevalência do degrau distal, embora essa relação tenha sido diagnosticada com maior freqüência nas crianças succionadoras. Por outro lado, a sobressaliência aumentada foi mais prevalente nos grupos experimentais (30,4, 29,3 e 43,0%, respectivamente) quando comparados ao grupo controle (22,2%). Em crianças com hábito de sucção persistente além dos 4 anos de idade, observou-se uma freqüência significativamente maior de sobressaliência aumentada em comparação ao grupo controle.

This research aimed the evaluation of the anteroposterior relationships of the primary second molars and incisors in pacifier users. Three dentists performed clinical examinations in 561 children at 3 to 6 years of age to record the relationships of the primary second molars, as well as to measure the amount of overjet. Out of the 336 children selected, 246 had a history of pacifier use and were assigned to three experimental groups according to the persistence of their pacifier habits: until 2 years of age, from 2 to 4 years of age, and from 4 to 6 years of age. The control group was composed by 90 children who were habit-free. The groups were compared according to the occlusal traits assessed, through the chi-square test (p < 0.05). The prevalence of mesial step was significantly lower in children who sustained their pacifier habits from 4 to 6 years of age. There were no significant differences between groups concerning the prevalence of distal step, although this relationship had been more frequently diagnosed in pacifier users. On the other hand, increased overjet was more prevalent in the experimental groups (30.4, 29.3, and 43.0%, respectively) compared with the control group (22.2%). There was a significantly higher frequency of increased overjet in comparison to the control group, in children who sustained their pacifier habits beyond 4 years of age.

Avaliação da espessura do esmalte proximal em segundos pré-molares superiores humanos e sua correlação com o diâmetro mésio-distal / Thickness valuation of adjacent enamel in second superior human pre molar teeth an their relationship with mesio distal diameter

A determinação da espessura do esmalte proximal à altura do ponto de contato é de grande importância, visto que o desgaste desta região dental é freqüentemente utilizado na clínica ortodôntica com a finalidade de correção de discrepâncias dentais e estabilidade do tratamento. Com o intuito de determinar os valores do diâmetro mésio-distal e aferir os valores médios da espessura do esmalte nas faces proximais à altura do ponto de contato, foram avaliados 42 segundos pré-molares superiores. Os diâmetros mésio-distais foram mensurados com auxílio de um paquímetro digital, em seguida foram incluídos em resina e seccionados obtendo-se uma lâmina central de 0,7 mm de espessura, possibilitando a medição da espessura do esmalte em um perfilômetro de precisão milesimal. Com base nos dados obtidos, também foram analisadas as possíveis correlações entre a espessura do esmalte nas faces proximais e o diâmetro mésio-distal. Os resultados indicaram que o valor médio do diâmetro mésio-distal é de 6,85 mm para o segundo pré-molar superior e com espessura media do esmalte de 1,101 mm na mesial e 1,157 mm na distal. De acordo com os testes de Spearman e Pearson foram encontradas correlações estatisticamente significantes no lado direito entre a espessura do esmalte na face mesial e o diâmetro mésio-distal, entre a espessura na face distal e o diâmetro mésio-distal. No lado esquerdo foram encontradas correlações positivas entre a espessura do esmalte distal e o diâmetro mésio-distal. Em ambos os lados houve correlações estatisticamente significantes entre a espessura do esmalte mesial e a espessura do esmalte distal. Independente do lado, a espessura média do esmalte é maior na face distal que na mesial.

Estudo do relacionamento ântero-posterior entre os arcos dentários decíduos, de crianças nipo-brasileiras, dos dois aos seis anos de idade / Study of the anteroposterior relationship between deciduous dental arches of Japanese-Brazilian children, from 2 to 6 years of age

OBJETIVO: verificar as prevalências dos diferentes tipos de relacionamentos ântero-posteriores entre os arcos dentários decíduos, bem como o possível dimorfismo sexual, em crianças nipo-brasileiras na faixa etária dos dois aos seis anos de idade. METODOLOGIA: foram avaliadas por inspeção visual 310 crianças nipo-brasileiras, matriculadas em 19 escolas do estado de São Paulo, sendo 154 do gênero masculino e 156 do feminino. Os resultados foram submetidos ao teste do qui-quadrado e revelaram ausência de dimorfismo sexual para a maioria dos relacionamentos analisados, permitindo apresentar os resultados conjuntamente para ambos os gêneros. RESULTADOS: as prevalências dos relacionamentos entre os segundos molares decíduos foram: 47,4 por cento para o degrau mesial, 41,3 por cento para o plano terminal reto, 5,5 por cento para o degrau distal e 5,8 por cento para os casos com assimetrias. Para os relacionamentos entre os caninos decíduos, conforme Foster e Hamilton, constataram-se prevalências de 77,4 por cento para a Classe 1, 6,8 por cento para a Classe 2, 6,8 por cento para a Classe 3 e 9 por cento para as relações assimétricas. Apenas a Classe 2 apresentou dimorfismo sexual, sendo de 3,9 por cento para o feminino e de 9,7 por cento para o masculino. Quanto à sobressaliência verificaram-se prevalências de 71,3 por cento para a normal, 14,2 por cento para a aumentada, 7,4 por cento para a mordida cruzada anterior e 7,1 por cento para a mordida topo-a-topo. RESULTADOS: concluiu-se que a maioria das crianças nipo-brasileiras avaliadas neste estudo, apresentaram um relacionamento ântero-posterior normal entre os arcos decíduos, merecendo atenção uma ligeira tendência para o desenvolvimento da Classe 3.

AIM: the purpose of this cross-sectional study was to verify the prevalences of different types of anteroposterior relationships between deciduous dental arches and its possible sexual dimorphism, in Japanese-Brazilian children from 2 to 6 years of age. METHODS: a total of 310 Japanese-Brazilian children from 19 schools in São Paulo, Brazil, comprising 154 males and 156 females, were examined by visual inspection. The qui-square statistical test was applied to evaluate the data, and the results revealed no statistically significant sexual dimorphism for the majority of types of anteroposterior relationship. Therefore, the results for both genders were grouped together. RESULTS: the prevalences of anteroposterior relationships between deciduous second molars were: mesial step, 47.4 percent; flush terminal plane, 41.3 percent; distal step, 5.5 percent and asymmetric cases, 5.8 percent. The prevalences of anteroposterior relationship of deciduous canines were: Class 1, 77.4 percent; Class 2, 6.8 percent; Class 3, 6.8 percent and asymmetric cases, 9 percent. Only Class 2 revealed sexual dimorphism: 3.9 percent for female and 9.7 percent for male. The prevalences of overjet, were: normal, 71.3 percent; increased, 14.2 percent; anterior cross-bite, 7.4 percent and edge-to-edge bite, 7.1 percent. CONCLUSION: it was concluded that the majority of Japanese-Brazilian children evaluated in this study showed normal anteriorposterior relationship between dental arches, with a slightly tendency for the development of Class 3.

Estudo comparativo das dimensões transversais dos arcos dentários entre jovens com oclusão normal e má oclusão de Classe II, 1ª divisão / A comparative study of arch widths of white Brazilians with normal occlusion and Class II, Division 1, malocclusion

OBJETIVO: avaliar as possíveis diferenças nas dimensões transversais dos arcos dentários superiores e inferiores entre jovens com oclusão normal e má oclusão de Classe II, 1ª divisão.METODOLOGIA: foram avaliados 170 pares de modelos em gesso de jovens brasileiros leucodermas, com dentadura permanente, sendo 76 com oclusão normal (41 do gênero feminino e 35 do masculino) e média de idade de 13 anos e 6 meses e 94 com má oclusão de Classe II, 1ª divisão (58 do gênero feminino e 36 do masculino) e média de idade de 13 anos e 9 meses. Este grupo com má oclusão foi dividido em duas categorias: Classe II sem apinhamento e Classe II com apinhamento. Compararam-se as distâncias intercaninos, interprimeiros pré-molares e intermolares, em ambos os arcos dentários.RESULTADOS: em relação ao grupo com oclusão normal, os jovens do gênero masculino evidenciaram as seguintes diferenças estatisticamente significantes: 1) distância intercaninos inferiores maior para o grupo com Classe II sem apinhamento; 2) distância interprimeiros pré-molares superiores menor para o grupo com Classe II sem apinhamento e 3) distâncias interprimeiros pré-molares e intermolares, superiores e inferiores, menores para o grupo com Classe II com apinhamento. Por sua vez, o gênero feminino evidenciou: 1) distâncias interprimeiros pré-molares e intermolares superiores menores para o grupo com Classe II sem apinhamento e 2) distâncias interprimeiros pré-molares e intermolares, superiores e inferiores, menores para o grupo com Classe II com apinhamento.CONCLUSÃO: de um modo geral, os jovens com má oclusão de Classe II, 1ª divisão, apresentaram uma tendência para deficiência transversal posterior dos arcos dentários, principalmente no grupo com apinhamento.