Paulo Eduardo Guedes Carvalho

Longitudinal effects of rapid maxillary expansion.

OBJECTIVE To evaluate the long-term effects of rapid maxillary expansion (RME) via banded expanders in the sagittal and vertical facial planes. MATERIALS AND METHODS The sample consisted of 25 patients who had undergone RME (with either Haas-type or Hyrax hygienic expanders) followed by standard edgewise orthodontic therapy. This sample was compared with a group of 25 patients who had edgewise treatment only and with a control nontreatment group of 26 subjects, matched by age and gender with the patients of the other two groups. Lateral cephalograms were taken before treatment (T1), at the end of treatment (T2), and at 3 years posttreatment (T3), comprising a 5-year average time of observation. RESULTS RME treatment, in the long-term, did not influence the sagittal position of the apical jaw bases or the facial vertical dimension. CONCLUSION Unfavorable cephalometric changes resulting immediately after RME are temporary, and therefore concerns about using RME in patients with vertical growth patterns or an extremely convex facial profile are not substantiated.

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.

Estudo cefalométrico da correlação da anatomia da base craniana com o padrão facial e as bases apicais

AIM: This cross-sectional study was conducted with the object of making a cephalometric evaluation of the cranial base anatomy correlation with the facial pattern and apical bases. METHODS: 88 lateral teleradiographies of young white Brazilian with mean age of 10.3 years were used. The Ricketts VERT index was used to determine the facial pattern, and the sample was distributed as follows: 37 in group M (mesofacial), 34 in group D (dolicofacial) and 17 in group B (brachyfacial). The anatomic drawing, demarcation of points, line and plane tracings, and linear and angular measurement gauging were done manually. The cranial base measurements used were S-N, N.S.Ba and S-N.Po-Or and the apical base measurements were S.N.A, S.N.B and A.N.B. RESULTS AND CONCLUSION: It was concluded that, in the correlation between the cranial base and the facial pattern, there was significance between the variable N.S.Ba and the VERT Index. In the correlation between the cranial base and the apical bases, there was significance between N.S.Ba and the variables S.N.A and S.N.B, and between S-N.Po-Or and the variables S.N.A and S.N.B.

The association between periodontal disease and seizure severity in refractory epilepsy patients

PURPOSE Periodontal diseases are common in most populations and affect people at all socioeconomic levels. Evidence suggests that patients with epilepsy actually have higher risks of dental disease and increased oral health needs, but the frequency and consequences of poor controlled seizures on dental and periodontal health have not been reported before. We aimed to assess the impact of seizure frequency on periodontal status and oral hygiene in a sample of epilepsy patients. METHODS One hundred and nine consecutive patients treated for epilepsy at the outpatient clinic of our University Hospital were invited to take part in an oral examination to determine their periodontal disease status, together with a control group. In addition, seizure frequency and use of medication were documented. RESULTS In logistic regression model, patients were significantly more susceptible to bad oral hygiene, gingivitis and periodontitis that controls (p<0.001); seizure frequency was significantly related to bad oral hygiene (p=0.010), gingivitis (p<0.001) and periodontitis (p<0.001). Tooth brushing habits and presence of caries were associated with oral health in patients group. CONCLUSION Our study found a significant positive correlation between periodontal disease and seizure severity. Epilepsy patients need to focus more on their oral health and quality of oral hygiene.

Comparative in vitro study of the shear bond strength of brackets bonded with restorative and orthodontic resins

The aim of this study was to evaluate the shear bond strength of brackets bonded with different restorative systems and compare it with that afforded by an established orthodontic bonding system. Seventy human bicuspids were used, divided into five different groups with 14 teeth each. Whereas a specific orthodontic bonding resin (Transbond™ XT) was used in the control group, the restorative systems Charisma, Tetric Ceram, TPH Spectrum and Z100 were used in the other four groups. Seven days after bonding the brackets to the samples, shear forces were applied under pressure in a universal testing machine. The data collected was evaluated using the ANOVA test and, when a difference was identified, the Tukey test was applied. A 5% level of significance was adopted. The mean results of the shear bond strength tests were as follows: Group 1 (Charisma), 14.98 MPa; Group 2 (Tetric Ceram), 15.16 MPa; Group 3 (TPH), 17.70 MPa; Group 4 (Z100), 13.91 MPa; and Group 5 or control group (Transbond™ XT), 17.15 MPa. No statistically significant difference was found among the groups. It was concluded that all tested resins have sufficient bond strength to be recommended for bonding orthodontic brackets.

Effects of masticatory hypofunction on mandibular morphology, mineral density and basal bone area

AIM: This experimental study investigated the association between masticatory hypofunction and mandibular morphological dimensions and internal bone characteristics. METHODS: Twentyfour 21-day-old male Wistar rats were randomly divided into two groups, according to the diet consistency. The control group (CG) was fed a solid diet (pellets) and the experimental group (EG) received a powdered diet during 50 days. All animals were euthanized and their mandibles removed and processed for histomorphometric analysis. A calibrated examiner performed linear and angular measurements (mandibular body length and height, mandibular lengths, ramus depth and height, mandibular base depth, mandibular head and gonial angle) on photographs, estimated bone density in the mandibular ramus region on digital radiographs and assessed the area of cortical and trabecular bone tissue in the second molar region, in 5-µm-thick serial cuts stained with Casons Trichrome. Measurements for the study groups were compared using Mann-Whitney test (α=0.05). larvae to induce experimental candidiasis, and after 24 hours, the survival rate was assessed. RESULTS: some of the macroscopic dimensions evaluated on photographs were significantly smaller in EG compared to CG, specifically mandibular ramus height (10.77 mm vs. 11.11 mm, p=0.0375), mandibular body length (21.67 mm vs. 22.36 mm, p=0.0165) and height (4.24 mm vs. 4.54 mm, p=0.0016), as well as mandibular base depth (1.24 mm vs. 1.47 mm, p=0.0325). The relative mineral bone density was significantly decreased in EG (1.04) compared to CG (1.25), p<0.001. Rats in the EG also presented smaller trabecular and cortical bone area (2.36 mm2) than those in CG (3.16 mm2), p<0.001. CONCLUSIONS: Based on the above-mentioned measurements, it may be concluded that masticatory hypofunction induced by a powdered diet affected mandibular morphology and was associated with significantly reduced bone content.

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.

Avaliação da resistência ao cisalhamento de braquetes da técnica lingual colados sobre superfície cerâmica

OBJETIVO: avaliar a resistencia ao cisalhamento de braquetes metalicos (American Orthodontics) utilizados na tecnica lingual, colados em facetas de cerâmica. METODOS: foram utilizados 40 corpos de prova divididos em quatro grupos de 10, de acordo com o material de colagem e do preparo da porcelana: Grupo I -resina Sondhi Rapid-Set e acido fluoridrico; Grupo II -resina Sondhi Rapid-Set e oxido de aluminio; Grupo III -resina Transbond XT e acido fluoridrico; e Grupo IV -resina Transbond XT e oxido de aluminio. Previamente a colagem, os braquetes foram preparados com base de resina de carga pesada (Z-250) e as facetas de cerâmica receberam aplicacao de silano. O teste de cisalhamento foi realizado por uma maquina de ensaios Kratos a uma velocidade de 0,5mm/min. RESULTADOS: os resultados obtidos foram analisados estatisticamente atraves do teste de Tukey (p<0,05) e demonstraram diferenca significativa entre os grupos I (2,77MPa) e IV (6,00MPa), e entre os grupos III (3,33MPa) e IV. CONCLUSOES: concluiu-se que a colagem de braquetes da tecnica lingual em superficie de cerâmica foi mais resistente ao cisalhamento com o uso de oxido de aluminio associado as duas resinas utilizadas neste estudo, porem a resina Transbond XT apresentou maior resistencia que a Sondhi Rapid-Set.

Avaliação cefalométrica da altura facial anteroinferior

Introducao: O presente estudo objetiva analisar cefalometricamente, em telerradiografias, a real participacao dos componentes maxilar, mandibular e dentoalveolar superior e inferior na constituicao da altura facial anteroinferior. Metodos: Foram utilizadas 40 telerradiografias de uma amostra composta por pacientes com maloclusoes de Classe I e Classe II de Angle, com idade variando entre 18 e 28 anos, sem terem sido submetidos a tratamento ortodontico previo e com a medida AFAI de 45 mm a 80 mm e ANB de 0o a 8o. Nos cefalogramas foram realizadas sete medidas lineares e duas angulares, que foram analisadas estatisticamente pelo coeficiente de correlacao de Pearson e o teste “t” de Student para a verificacao de correlacoes significantes entre as diversas variaveis estudadas (valor de p ≤ 0,05). O teste de Kolmogorov-Smimov determinou os indices de proporcionalidade para a altura da denticao e para a altura facial inferior. Resultados: Os resultados evidenciaram correlacao positiva entre a altura facial anteroinferior (ENA-Me) e os componentes dentoalveolares superior e inferior (1s-A e 1i-Pm), e correlacao entre as bases osseas maxilar (ENA-A) e mandibular (Pm-Me). Conclusao: Concluiu-se que os componentes dentoalveolar e osseo estao interligados na constituicao da AFAI, de modo que, na deficiencia de um e/ou de outro, a maloclusao se expressa em sentido vertical.