Evaluation of miniscrew angulation in the posterior maxilla using cone-beam computed tomographic image.

OBJECTIVE: This study aimed at evaluating whether changes in the insertion angle is a determining factor in the positioning of the miniscrews body in a region with larger interradicular space in the posterior maxilla. METHODS: Analysis of 60 posterior maxillary quadrants were made using images obtained by means of cone-beam computed tomographic image (CBCT), with 0.076-mm voxel, which presented a real miniscrew inserted in the mesial region of the maxillary first molars, serving as reference point for the placement of the virtual miniscrews. Measurements of the distances between roots were made in three points on the body of the virtual miniscrews (A, B and C), at four different angulations, 70o, 60o, 50o and 40o (T1 to T4), in relation to the long axis of the second premolar. This evaluation was made in four groups, selected in accordance with the disposition of the roots of the second premolars and first molars: Group 1 (all types of roots), Group 2 (convergent roots), Group 3 (divergent roots) and Group 4 (parallel roots). RESULTS: There were no statistically significant differences in the measurements of points A, B and C, at the different angles (70o, 60o, 50o and 40o) and in the different groups (p > 0.05). CONCLUSIONS: Changes in the insertion angle is not a determinant factor in the positioning of miniscrews body in regions with larger interradicular space in posterior maxilla.

Evaluation of miniscrew angulation in the posterior maxilla using cone-beam computed tomographic image

ABSTRACT Objective: This study aimed at evaluating whether changes in the insertion angle is a determining factor in the positioning of the miniscrews body in a region with larger interradicular space in the posterior maxilla. Methods: Analysis of 60 posterior maxillary quadrants were made using images obtained by means of cone-beam computed tomographic image (CBCT), with 0.076-mm voxel, which presented a real miniscrew inserted in the mesial region of the maxillary first molars, serving as reference point for the placement of the virtual miniscrews. Measurements of the distances between roots were made in three points on the body of the virtual miniscrews (A, B and C), at four different angulations, 70o, 60o, 50o and 40o (T1 to T4), in relation to the long axis of the second premolar. This evaluation was made in four groups, selected in accordance with the disposition of the roots of the second premolars and first molars: Group 1 (all types of roots), Group 2 (convergent roots), Group 3 (divergent roots) and Group 4 (parallel roots). Results: There were no statistically significant differences in the measurements of points A, B and C, at the different angles (70o, 60o, 50o and 40o) and in the different groups (p > 0.05). Conclusions: Changes in the insertion angle is not a determinant factor in the positioning of miniscrews body in regions with larger interradicular space in posterior maxilla.

RESUMO Objetivo: o presente estudo objetivou avaliar se alterações no ângulo de inserção do miniparafuso são um fator decisivo para a adaptação do corpo do parafuso em áreas com espaço inter-radicular aumentado, na região posterior da maxila. Métodos: foram realizadas análises em 60 quadrantes maxilares posteriores, a partir de imagens obtidas por tomografia computadorizada de feixe cônico (TCFC), com voxel de 0,076 mm, as quais apresentavam um miniparafuso real inserido na região mesial dos primeiros molares superiores, utilizado como ponto de referência para a inserção de miniparafusos virtuais. As distâncias inter-radiculares foram mensuradas utilizando-se três pontos marcados no corpo dos miniparafusos virtuais (A, B e C), inseridos com quatro angulações diferentes (70°, 60°, 50° e 40°) (T1 a T4) em relação ao longo eixo do segundo pré-molar. A avaliação foi realizada em quatro grupos, selecionados de acordo com a disposição das raízes dos segundos pré-molares e primeiros molares: Grupo 1 - contendo todos os tipos de raízes; Grupo 2 - raízes convergentes; Grupo 3 - raízes divergentes; e Grupo 4 - raízes paralelas. Resultados: não houve diferença estatisticamente significativa entre as medidas dos pontos A, B e C nas diferentes angulações (70°, 60°, 50° e 40°) ou entre os grupos (p > 0,05). Conclusões: alterações no ângulo de inserção dos miniparafusos não são um fator decisivo para a adaptação do corpo do parafuso, em áreas com espaço inter-radicular aumentado entre primeiro molar e segundo pré-molar superiores.

Debonding forces of different pads in a lingual bracket system.

OBJECTIVE:: To evaluate the shear bond strength of lingual orthodontic brackets with resin or metal pads, the location of bond failure and the adhesive remnant index (ARI). METHODS:: A total of 40 extracted upper premolars were randomly divided into two groups of 20 each: bonding with brackets having (1) pads with extended resin directly on the lingual surface of teeth, and (2) pads with metal custom base on the lingual surface of teeth. The debonding force was measured with an Instron universal testing machine. A Student's t-test was used to assess the difference between groups (α = 0.05). RESULTS:: The results showed a significant difference between the groups (p < 0.001). The shear bond strength of metal pads was significantly higher than resin pads. CONCLUSIONS:: Within the limitations of this in vitro study, it was concluded that the bond strength of lingual brackets with metal pads was higher than that of brackets with composite resin pads, due to the metal part being a single unit and welded. The failure location in the region between the bracket and the resin pad affected a higher percentage of the resin pads than the metal pads.

Debonding forces of different pads in a lingual bracket system

ABSTRACT Objective: To evaluate the shear bond strength of lingual orthodontic brackets with resin or metal pads, the location of bond failure and the adhesive remnant index (ARI). Methods: A total of 40 extracted upper premolars were randomly divided into two groups of 20 each: bonding with brackets having (1) pads with extended resin directly on the lingual surface of teeth, and (2) pads with metal custom base on the lingual surface of teeth. The debonding force was measured with an Instron universal testing machine. A Student's t-test was used to assess the difference between groups (α = 0.05). Results: The results showed a significant difference between the groups (p < 0.001). The shear bond strength of metal pads was significantly higher than resin pads. Conclusions: Within the limitations of this in vitro study, it was concluded that the bond strength of lingual brackets with metal pads was higher than that of brackets with composite resin pads, due to the metal part being a single unit and welded. The failure location in the region between the bracket and the resin pad affected a higher percentage of the resin pads than the metal pads.

RESUMO Objetivo: avaliar a resistência de união ao cisalhamento de braquetes ortodônticos linguais com pads em resina e metálicos, assim como os locais de ocorrência das falhas, além do Índice de Adesivo Remanescente (ARI). Métodos: 40 pré-molares superiores extraídos foram aleatoriamente divididos em dois grupos de 20 espécimes cada, para a colagem de braquetes com: 1) pads em resina, estendida diretamente na face lingual dos dentes; e 2) pads com base metálica customizada, na face lingual dos dentes. A força de descolagem dos braquetes foi mensurada por meio de uma máquina de ensaio universal (Instron). O teste t de Student foi utilizado para avaliar diferenças intergrupos (α = 0,05). Resultados: os resultados demonstram haver diferença significativa intergrupos (p < 0,001). A resistência de união ao cisalhamento dos pads metálicos foi significativamente maior em comparação aos pads em resina. Conclusões: dentro das limitações desse estudo in vitro, foi possível concluir que a resistência de união de braquetes linguais com pads metálicos foi superior à resistência de braquetes com pads em resina composta, uma vez que os pads metálicos customizados e os braquetes são fundidos, formando uma única unidade. A porcentagem de falhas de colagem na região entre o braquete e o pad foi maior para os pads em resina, em comparação aos pads metálicos.

Temporomandibular disorders and quality of life among 12-year-old schoolchildren.

OBJECTIVES: The aim of this study was to investigate the association between symptoms of temporomandibular disorders (TMD), quality of life, and malocclusion. METHODS: A cross-sectional observational design study was utilized among 248 schoolchildren aged 12 years old. Symptoms of TMD were assessed using the Orofacial Pain and Temporomandibular Disorders Triage Questionnaire, and subjects were further evaluated as oral-health-related quality of life (CPQ11-14), tooth clenching/grinding and malocclusion (Dental Aesthetic Index). Chi-square for independence, Odds Ratio and Mann-Whitney test were used (p = 0.05) statistically. RESULTS: Statistically, association was detected between TMD symptoms with pain and worse quality of life (p < 0.0138), and pain with quality of life and clenching/grinding (p = 0.0120 and 0.0007). DISCUSSION: The symptoms of TMD are associated with pain and teeth clenching, causing a negative impact on schoolchildren's quality of life; thus, a study of the TMD impact on quality of life is justified.

Association between malocclusion and the contextual factors of quality of life and socioeconomic status.

INTRODUCTION: The purpose of this study was to examine associations among malocclusion and the contextual factors of quality of life and socioeconomic status. METHODS: A cross-sectional study was conducted with a population-based sample of 1256 children from 7 to 10 years old. Malocclusion was assessed clinically; oral health-related quality of life (OHRQoL) was assessed using the Brazilian version of the child perceptions questionnaire; socioeconomic status was determined from data made available by the Research and Planning Institute of Piracicaba, São Paulo, Brazil. Initially, bivariate analyses were performed; after this, starting with variables with P ≤0.20, multilevel multiple logistic regression models were estimated, in which the binomial distribution, function of the logistic connection, and criteria for remaining in the model at P ≤0.05 were considered. RESULTS: Of the children, 82.1% had some type of malocclusion. Increased age associated with low socioeconomic status was the determinant for occlusal problems. The determination of low OHRQoL appears to be associated with the socioeconomic status in the individual factors, and increased overjet appears to be associated with factors at the contextual level. CONCLUSIONS: Socioeconomic status and age are risk factors for malocclusion. Of the malocclusions evaluated, increased overjet had the most negative influence on the OHRQoL.

Desimpactação de molar inferior usando arco lingual soldado como ancoragem / Disimpaction of mandibular molar using welded lingual arch as anchorage

O presente trabalho tem o objetivo de relatar a utilização do arco lingual soldado para a correção de segundos molares inferiores impactados. A impactação é uma alteração dentária relativamente rara, mais comum no arco inferior e, unilateralmente, do lado direito e em pacientes do sexo masculino, com etiologia multifatorial. Sua desimpactação é indicada, pois evita a reabsorção da raiz do dente adjacente, cárie, problemas periodontais, entre outros. Os pacientes descritos apresentavam más oclusões distintas, porém os segundos molares inferiores impactados de forma semelhante. Foi indicada a colocação do arco lingual fixo, modificado com extensões e ganchos soldados nas bandas que receberam força por meio de elástico em cadeia adaptado ao botão colado nos segundos molares, pois é dispositivo de ancoragem de fácil confecção, baixo custo, resistente, que interfere pouco na fonação, deglutição, mastigação e espaço da língua, além de ser estético e não depender da colaboração do paciente. Após três meses os segundos molares apresentaram-se bem posicionados. Concluiu-se que o arco lingual modificado mostrou-se eficiente na correção da impactação dos segundos molares inferiores

The aim of this study is to relate the use of a welded lingual arch for correction of impacted second molars. Impaction is a relatively rare dental alteration with multifactorial etiology, more common in the mandibular arch, unilaterally, on the right side in male patients. Disimpaction is indicated as this prevents resorption of the adjacent tooth root, caries, and periodontal problems.The studied patients presented different malocclusions, but similar impaction of the mandibular second molar. The indicated procedure was the placement of a fixed lingual arch, modified with extensions and hooks welded onto the bands, which received force by means of elastic chains adapted to the button bonded on second molars. This anchorage device is easy to fabricate, low cost, resistant, and causes little interference in phonation, swallowing, chewing and tongue space and in addition preserves aesthetics and does not depends on patient’s compliance. After 3 months the second molars were well positioned. It was concluded that the modified lingual arch has proven to be efficient in the correction of impacted mandibular second molars.

Preparo ortodôntico em cirurgia ortognática / Orthodontic preparation in orthognathic surgery: clinical case report

A deformidade dentofacial é um problema severo de má-oclusão, que pode provocar alterações na estética facial, problemas mastigatórios, desordens temporomandibulares, alterações na respiração e na fala. O tratamento desta má-oclusão, na idade adulta, envolve a correção ortodôntica combinada com a cirurgia ortognática. O preparo ortodôntico-cirúrgico merece considerável atenção em relação às descompensações dentárias, com a finalidade de permitir correto posicionamento das bases ósseas durante a cirurgia ortognática. O objetivo deste trabalho foi discorrer sobre os pontos importantes do preparo ortodôntico-cirúrgico, a fim de permitir uma adequada correção estética e funcional da oclusão.

Dentofacial deformity is a severe problem of malocclusion that may cause alterations in facial esthetics, masticatory problems, temporomandibular disorders, alteration in respiration and speech. Treatment of this malocclusion at an adult age involves orthodontic correction combined with orthognathic surgery. Orthodontic-surgery preparation deserves considerable attention as regards dental decompensations, with the purpose of allowing correct positioning of the bony bases during orthognathic surgery. The aim of this study is to discourse about important points of orthodontic-surgery preparation, in order to allow adequate static and functional correction of the malocclusion.

Evaluation of bonded orthodontics brackets using different adhesive systems after a cariogenic challenge.

AIM: The aims of this study were to evaluate the prevention of enamel demineralization and the shear bond strength (SBS) of orthodontic brackets bonded with fluoride and no fluoride conventional and self-etching adhesives and to analyze the characteristics of enamel near the bond area using a polarized light microscope (PLM) following demineralization and remineralization cycling (Des Re). METHODS AND MATERIALS: Fifty bovine incisors were selected and divided into five groups according to the adhesive system used during the bonding process: G1, Transbond XT Adhesive; G2, Single Bond 2 Adhesive; G3, Optibond Solo Plus; G4, Clearfil SE Bond; and G5, Clearfil Protect Bond. Transbond XT was used to fix the brackets to the teeth in all groups. After bonding, the groups were separated into cycling and control subgroups. The specimens were submitted to SBS testing and evaluated under a PLM. The results were submitted to ANOVA and Tukey's post hoc tests (p<.05). RESULTS: There were no significant differences for SBS after Des-Re cycling. The Clearfil Protect Bond showed the SBS to be statistically lower than the other adhesives used for the control groups. After a cariogenic challenge, the Single Bond adhesive showed an SBS significantly lower than Transbond XT. The Des-Re cycling increased the enamel demineralization induced after the cariogenic challenge. CONCLUSIONS: The cariogenic challenge did not reduce the SBS. Optibond Solo Plus and Transbond XT adhesives presented the highest SBS while Clearfil Protect Bond had the lowest. The PLM showed that the cariogenic challenge increased the enamel demineralization for all adhesives evaluated, independent of the presence of fluoride. CLINICAL SIGNIFICANCE: An alternative material with the ability to prevent enamel demineralization should be used in orthodontic patients due to the higher accumulation of plaque around orthodontic brackets.