Rhita Cristina Cunha Almeida

Soft tissue response to mandibular advancement using 3D CBCT scanning

This prospective longitudinal study assessed the 3D soft tissue changes following mandibular advancement surgery. Cranial base registration was performed for superimposition of virtual models built from cone beam computed tomography (CBCT) volumes. Displacements at the soft and hard tissue chin (n = 20), lower incisors and lower lip (n = 21) were computed for presurgery to splint removal (4-6-week surgical outcome), presurgery to 1 year postsurgery (1-year surgical outcome), and splint removal to 1 year postsurgery (postsurgical adaptation). Qualitative evaluations of color maps illustrated the surgical changes and postsurgical adaptations, but only the lower lip showed statistically significant postsurgical adaptations. Soft and hard tissue chin changes were significantly correlated for each of the intervals evaluated: presurgery to splint removal (r = 0.92), presurgery to 1 year postsurgery (r = 0.86), and splint removal to 1 year postsurgery (r = 0.77). A statistically significant correlation between lower incisor and lower lip was found only between presurgery and 1 year postsurgery (r = 0.55). At 1 year after surgery, 31% of the lower lip changes were explained by changes in the lower incisor position while 73% of the soft tissue chin changes were explained by the hard chin. This study suggests that 3D soft tissue response to mandibular advancement surgery is markedly variable.

Efficiency of light-emitting diode and halogen units in reducing residual monomers.

INTRODUCTION In this in-vitro study, we aimed to compare the residual monomers in composites beneath brackets bonded to enamel, using a light-emitting diode (LED) or a halogen unit, and to compare the residual monomers in the central to the peripheral areas of the composite. METHODS Twenty bovine teeth preserved in 0.1% thymol were used in this study. Ten teeth were used to standardize the thickness of the composite film, since different thicknesses would cause different absorbance of light. Brackets were bonded to 10 bovine incisors, with the halogen light (n = 5) and the LED (n = 5). The brackets were debonded, and the remaining composite on the enamel surface was sectioned in 2 regions: peripheral (0.8 mm) and central, resulting in 2 subgroups per group: central halogen (n = 5), peripheral halogen (n = 5), central LED (n = 5), and peripheral LED (n = 5). The spectrometric analysis in the infrared region was used to measure the free monomers with the attenuated total reflectance method. RESULTS Normal distribution was tested by using the Kolmogorov-Smirnov test. Data were compared by 2-way analysis of variance (ANOVA) at P <0.05. The LED group showed fewer residual monomers than did the halogen group (P = 0.014). No differences were found among the regions (P = 0.354), and there were no interactions between light type and region (P = 0.368). CONCLUSIONS LED leaves less residual monomer than does the halogen light, even with half of the irradiation time; there were no differences between the central and peripheral regions, and no interaction between light type and region.

A estética no sistema de braquetes autoligáveis

INTRODUCTION: The self-ligating system was introduced aiming the reduction of chair time. Once this system does not need any ligation form, several advantages were observed, such as the reduction on superficial friction in couple bracket/ orthodontic wire, and the reduction on the force level that is necessary to establish the orthodontic tooth movement. The growing demands of aesthetic patients induced the self-ligating system to be made of polycarbonate material, resulting in unique aesthetic advantages when compared with the metallic form of this system. AIM: The objective of this paper was to proceed with a literature review about aesthetic self-ligating brackets.

Levels of gingival crevicular fluid matrix metalloproteinases in periodontally compromised teeth under orthodontic forces

OBJECTIVE To examine levels of matrix metalloproteinases (MMPs)-1, -2, -3, -7, -8, -12, and -13 in the gingival crevicular fluid (GCF) of periodontally compromised teeth at different time points during orthodontic movement. MATERIALS AND METHODS Ten controlled periodontitis subjects were submitted to orthodontic treatment. One dental arch was subjected to orthodontic movement, and teeth in the opposite arch were used as controls. GCF samples were collected from the lingual sites of two movement and two control incisors 1 week before orthodontic activation (-7 d), immediately after orthodontic activation, and after 1 hour, 24 hours, and 7, 14, and 21 days. Multiplexed bead immunoassay was used to measure MMPs in GCF. Data were analyzed using Friedman and Wilcoxon statistical tests. RESULTS The only significant change found over time was in the levels of MMP-1 in the movement group (P < .05). When the two groups were compared after activation, the only statistically significant difference found was in levels of MMP-12 24 hours after activation (P < .05). CONCLUSIONS Our findings suggested that the orthodontic movement of periodontally compromised teeth without active pockets did not result in significant changes in the GCF levels of MMPs.

Comparação entre a radiografia de cavum e a cefalométrica de perfil na avaliação da nasofaringe e das adenoides por otorrinolaringologistas

INTRODUCAO: tanto a radiografia cefalometrica de perfil quanto a de cavum permitem a avaliacao do espaco aereo nasofaringeo (EAN). Nao e rara a solicitacao dos otorrinolaringologistas de radiografia de cavum, mesmo o paciente possuindo uma cefalometrica. OBJETIVOS: objetivou-se (a) conhecer quais exames os otorrinolaringologistas solicitam para avaliar o EAN; (b) verificar o conhecimento da cefalometrica por otorrinolaringologistas; (c) comparar a avaliacao de otorrinolaringologistas nas duas tecnicas radiograficas para a medicao e a visualizacao do EAN e da adenoide; (d) correlacionar os resultados do metodo de inspecao visual com os da medicao de Schulhof. METODOS: foram obtidas, no mesmo dia, radiografias cefalometricas e de cavum de 15 pacientes respiradores bucais. Essas foram cobertas com papel cartao, deixando visivel apenas o EAN e adenoides e foram avaliadas por 12 otorrinolaringologistas. Estes respondiam sobre sua familiaridade com a cefalometrica, quais exames solicitam para visualizar EAN e adenoides e se utilizam algum metodo de medicao do grau de obstrucao. Avaliavam qual das radiografias apresentava a melhor visualizacao da adenoide e do EAN, e classificavam o tamanho dos mesmos em pequeno, medio ou grande, atraves de metodo visual. RESULTADOS: os resultados demonstraram que todos os otorrinolaringologistas costumam solicitar a radiografia de cavum. Apenas um solicita a cefalometrica, dois estao familiarizados com essa tecnica e um utiliza algum metodo de medicao do EAN. A cefalometrica foi preferida por 49,4% dos otorrinolaringologistas, a de cavum por 22,8%, enquanto 27,8% nao observaram diferenca entre ambas. Foi encontrada baixa correlacao entre o metodo de medicao visual e o de Schulhof.

Three-dimensional surface models of the facial soft tissues acquired with a low-cost scanner

Although there has been an increase in three-dimensional (3D) scanning methods available on the market, they are generally expensive. The DI3D system is considered a good scanner for the acquisition of soft tissue surface images. The Microsoft Kinect scanner is a much more affordable alternative for acquiring 3D models. The aim of this study was to determine whether the precision and accuracy of Kinect are similar to those of DI3D. To verify the accuracy, 10 patients were scanned with both methods The models of each patient acquired from the two scanners were superimposed using a surface-to-surface registration technique, and the distances between the models were recorded for 10 different anatomical regions of interest. For the evaluation of precision, one patient was scanned 11 different times with the Kinect scanner, and these models were compared using the same superimposition method. It was found that the average difference between the two methods was 0.3±2.03mm. The assessment of reproducibility showed an average difference between the images taken with Kinect of 0.1±0.6mm (P<0.05, one-sample t-test). Thus, Kinect showed good precision and reasonable accuracy, and appears to be an interesting and promising resource for facial analysis.

Different strategies used in the retention phase of orthodontic treatment

OBJETIVO: identificar as condutas clinicas mais utilizadas, considerando-se as seguintes variaveis: 1) aparelhos utilizados; 2) periodo de utilizacao; 3) protocolo de utilizacao, em horas diarias, e sua evolucao com o passar dos meses; 4) percentual de pacientes controlados 1 ano pos-tratamento; e 5) as recidivas mais frequentemente observadas. METODOS: utilizou-se um questionario distribuido para todos os cursos de Especializacao em Ortodontia cadastrados no CFO ate outubro de 2005. RESULTADOS E CONCLUSAO: foram obtidos 91 questionarios validos. Para a analise dos dados, utilizou-se estatistica descritiva e os testes qui-quadrado para tendencia linear e qui-quadrado para tendencia linear multivariado. Concluiu-se que: 1) na arcada superior, os aparelhos mais utilizados foram o aparelho de Hawley, o wraparound e a placa de acetato; ja na inferior, barra de fio multifilamentado, barra de aco sem colagem em incisivos e barra com colagem nos incisivos; 2) indicou-se sua utilizacao por mais de 24 meses para a arcada superior, com uma tendencia de menor utilizacao nessa arcada do que na inferior; 3) o protocolo de utilizacao na arcada superior inicia-se com 24 horas/dia, reduzindo-se apos o segundo ano; para a arcada inferior, o protocolo em horas/dia foi estavel; 4) apos um ano de contencao, foram reexaminados mais de 50% dos casos tratados; 5) as recidivas mais comuns foram apinhamento inferior, giroversoes e reabertura de diastemas.

Orthosurgical treatment of patients in the growth period: at what cost?

Awaiting growth to end prior to starting orthosurgical treatment is sometimes extremely difficult for patients suffering from severe facial deformities. In cases of substantial skeletal disharmonies surgery may be indicated during active growth phase when the patient is psychosocially, aesthetically and/or functionally compromised. To indicate this therapy, orthodontic criteria, such as mild intramaxillary discrepancy and the possibility of preoperative preparation without major dental repositioning, must be met. A second orthosurgical treatment will probably prove necessary after growth has ended. This treatment should not be considered as routine, but rather as a therapeutic option in carefully selected cases.

Side effects of intraoral devices for OSAS treatment

INTRODUCTION Intraoral devices have increasingly assumed a key role in the treatment of obstructive sleep apnea syndrome, but there are limitations to their indication and side effects that result from their continuous use, as well as the use of the continuous positive airway pressure device. OBJECTIVES To evaluate the changes in dental positioning caused by the continuous use of mandibular advancement devices. METHODS A prospective longitudinal study with a sample of 15 patients, with evaluation of complete documentation after a mean time of 6.47 months, assessed changes in dental positioning due to the use of the Twin Block oral device for the treatment of patients with apnea. The following variables were evaluated: overjet, overbite, upper and lower intermolar distances, upper and lower intercanine distances, Littles irregularity index and the incisor mandibular plane angle. An intraclass correlation test was performed and a correlation index>0.08 was accepted. After verifying the normal sample distribution (Shapiro-Wilks), a parametric test was used (t test), with a significance level set at 5%. RESULTS There was a decrease in the values of overjet, overbite and Littles irregularity index, whereas there was an increase in the lower intercanine distance and IMPA values. All these variables are influenced, at different levels, by the forward inclination of the lower incisors, an action that can be expected due to the force applied by the device on the dentition. The other variables did not show statistically significant differences. CONCLUSION After a mean time of 6.47 months of use of the mandibular advancement device, there were statistically significant changes in the dental positioning, but they were not clinically relevant. However, it is relevant that this device is commonly in use over long periods of time, making the monitoring of these patients of the utmost importance for the duration of their therapy.

Controlled tooth movement to correct an iatrogenic problem

This case report describes the treatment of a 9-year old boy, who had his maxillary central incisors extruded by noncontrolled elastic mechanics to close a diastema. The article describes the consequences of this movement and how the problem was solved with controlled intrusion.