Effets sur l'articulation temporo-mandibulaire du Twin-Block et d'un appareil myofonctionnel de classe II.

Introduction. Ce projet de recherche consiste en une étude cohorte prospective randomisée visant à évaluer les douleurs ressenties au niveau de l’articulation temporo-mandibulaire (ATM) lors d’une thérapie d’avancement mandibulaire grâce à un appareil fixe, le correcteur de classe II (CC) et d’un appareil amovible, le Twin-Block (TB). Matériels et méthodes. Cette étude comptait 26 patients (11 hommes et 15 femmes), âge moyen de 12ans 10mois (10ans 4mois à 15ans 10mois). Les sujets devaient avoir une malocclusion de classe II et être en croissance, CVM 2 ou 3 (Cervical Vertebral Maturation). Les patients étaient divisés en deux groupes : TB et CC. La douleur était évaluée selon l’axe I de l’examen du RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorders) à 7 reprises (T0 à T6). De plus, le patient devait remplir un questionnaire, à la maison, sur la douleur ressentie et la médication prise lors des 30 premiers jours. La douleur était évaluée avant l’insertion des appareils (T0), à 1 semaine (T1) post-insertion, 4 semaines plus tard (T2), 8 semaines (T3) où une expansion de 20 tours (environs 5 mm) était débutée, ensuite (T4) (T5) et (T6) chacun à 8 semaines d’intervalles. Les tests statistiques utilisés dans cette étude : le test «Wilcoxon à un échantillon» ainsi que le test «Mann-Whitney à échantillons indépendants ». Résultats et Discussion. La douleur à l’examen clinique est variable mais tend à diminuer avec le temps. Aucune différence, statistiquement significative, ne fut observée entre les 2 groupes en ce qui à trait aux diverses palpations effectuées. Parmi les patients ayant rapporté de la douleur, 40% l’ont ressentie surtout le matin et 63,3% ont dit qu’elle durait de moins d’une heure jusqu’à quelques heures. Conclusion. D’après nos résultats, lors d’une thérapie myofonctionnnelle, il n’y a pas de différence statistiquement significative entre la douleur occasionnée par un Twin-Block et celle produite par un correcteur de classe II fixe au niveau de l’ATM et des muscles du complexe facial.

Assessing the benefits of domestic hot fill washing appliances

Washing machine and dishwasher appliance use accounts for approximately 10% of electricity demand in EU households. The majority of this demand is due to the operation of electric heating elements inside appliances. This paper investigates the potential benefits that can be realised by adding a hot fill connection to washing appliances, with respect to carbon emissions, demand side management and renewable energy integration. Initial laboratory testing of new hot and cold fill appliances has resulted in modifications to optimise hot fill intake, and a novel numerical model presents a method of characterising appliance electricity use in different configurations. In order to validate model findings and test the use of new hot fill appliances in situ, a pilot study has recorded appliances’ resource consumption at one-minute resolution in fourteen households. The addition of hot fill reduced the total dishwasher and washing machine electricity consumption by 38% and 67% respectively. Depending on how hot water is supplied to appliances it is estimated that hot fill use results in an annual household carbon saving of up to 147 kgCO2. Further to direct electricity reduction, hot fill appliances can offer a method of time shifting demand away from peak periods without inconveniencing occupants’ lifestyles.

New material for orthopedic implants: Electrochemical study of nickel free P558 stainless steel in minimum essential medium

Nickel, a component of stainless steels (SS) applied in orthopedic implants may cause allergic processes in human tissues P558 nickel free SS was studied to verify its viability as a substitute for stainless steel containing nickel Its performance is compared to ISO 5832-9 and F138 most used nowadays grades in implants fabrications, in minimum essential medium. MEM, at 37 degrees C. Potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and ""in vitro"" cytotoxicity were used as techniques. From the electrochemical point of view P558 SS is comparable to ISO 5832-9 SS in MEM It remains passivated until the transpassivation potential, above which generalized corrosion occurs F138 presents pitting corrosion at 370 mV/SCE. The cytotoxicity results showed that P558. ISO 5832-9 and F138 do not present cytotoxic character Therefore, these results suggest that P558 SS can be applied in orthopedic implants (C) 2010 Elsevier BV All rights reserved

Acumulação de competências tecnológicas e os processos subjacentes de apredizagem: o caso da Invensis Appliances Controls Unidade Vacaria - RS

Esta dissertação enfoca o relacionamento entre acumulação de competências tecnológicas e os processos subjacentes de aprendizagem. Este relacionamento é examinado na empresa Invensys Appliance Controls Ltda. - Unidade de Vacaria/RS, durante o período de 1981 a 2000. Trata-se de uma empresa metal-mecânica, fornecedora da indústria de linha branca. Em outras palavras, a dissertação examina as implicações dos processos subjacentes de aprendizagem tecnológica para a acumulação de competências para três funções tecnológicas: processo e organização da produção, produtos e equipamentos. Os processos de aprendizagem são examinados à luz de quatro características: variedade, intensidade, funcionamento e interação, a partir do uso de estruturas de análise existente na literatura. Baseado em estudo de caso individual, este estudo encontrou que a maneira e a velocidade de acumulação de competências tecnológicas na empresa estudada estão associadas aos diversos processos usados para adquirir conhecimento tecnológico e convertê-lo em organizacional. Ademais, a simples incidência desses processos na empresa não garantiu na empresa uma implicação positiva para a acumulação de competências tecnológicas. Através do uso de estrutura existente na literatura, porém aplicada a uma indústria diferente de estudos anteriores, esta dissertação sugere que deve existir um esforço organizado, contínuo e integrado para geração e disseminação de conhecimento em toda a empresa a fim de que a acumulação de capacitação tecnológica seja acelerada na empresa.

Ximelagatran versus warfarin for prophylaxis of venous thromboembolism in major orthopedic surgery: systematic review of randomized controlled trials

INTRODUÇÃO: O ximelagatrano foi recentemente estudada para profilaxia do tromboembolismo venoso (TEV). OBJETIVO: Avaliar se o ximelagatrano comparado com a varfarina melhora a profilaxia do TEV em pacientes submetidos à cirurgia ortopédica do joelho. FONTE DE DADOS: Estudos randomizados identificados por pesquisa eletrônica na literatura médica, até 2006, cujos dados foram compilados no programa Review Manager, versão 4.2.5. RESULTADOS: Foram incluídos três estudos randomizados bem conduzidos envolvendo 4.914 participantes. Foram definidos dois sub-grupos com dosagens diferentes de ximelagatrano (24 mg and 36 mg, duas vezes ao dia). O tratamento com ximelagatrano mostrou freqüência significantemente menor de TEV que o tratamento com varfarina, mas somente na dosagem de 36-mg [risco relativo, RR 0.72 ([intervalo de confiança, IC, 95% 0.64, 0.81), p < 0.00001]. A freqüência de TEV no sub-grupo de 24-mg foi similar a da varfarina [RR 0.86 (IC 95% 0.73, 1.01), p = 0.06]. Para TEV maior, embolia pulmonar, sangramento e sangramento maior não houve diferença entre varfarina e a ximelagatrano. Ao final do tratamento, a elevação da alanino-aminotransferase (ALT) foi menos freqüente no sub-grupo de 24 mg de ximelagatrano que no grupo da varfarina [RR 0.33 (IC 95% 0.12, 0.91) p = 0.03], mas no período de acompanhamento essa elevação foi maior com 36 mg de ximelagatrano [RR 6.97 (IC 95% 1.26, 38.50) p = 0.03]. CONCLUSÃO: O ximelagatrano foi mais efetivo que a varfarina quando usado em dosagens maiores (36 mg, 2 vezes ao dia), mas às expensas de aumento de enzimas hepáticas no período de acompanhamento.

Assessment of mechanical properties and dimensions of suture threads utilized in orthopedic surgeries

Fios de sutura de náilon (0, 3-0 e 4-0), poliéster trançado (0, 3-0 e 4-0) e polipropileno (0, 3-0 e 4-0) de 7 marcas comercializadas no Brasil, foram submetidos a análise de diâmetro, comprimento, resistência do encastoamento, resistência à tração do fio sem nó e resistência à tração do fio com nó, segundo metodologia padronizada pela Associação Brasileira de Normas Técnicas (ABNT). Os resultados obtidos indicam que a maioria dos fios testados encontra-se dentro dos valores preconizados pela ABNT.

Rapid palatal expansion: a comparison of two appliances

This study analyzed occlusal radiographs to compare the transverse changes produced in patients treated with rapid maxillary expansion using two types of appliances. The sample consisted of 31 children aged 7 to 10.6 years, of both genders, with posterior cross-bite. Fifteen children were treated with a tooth-borne expander and 16 were treated with a tooth-tissue-borne expander. Occlusal radiographs obtained at treatment onset and at the end of the retention period were digitized. The following variables were measured: intermolar distance (IMD), interapical distance (IApD), interbase distance (IBaD) and interarm distance (IArD). The results revealed increases in all measurements in both groups after rapid maxillary expansion. Comparison between groups revealed that the increases were greater in patients treated with the tooth-borne expander, except for the IArD measurement, which presented the same increase in both groups. Even though the IMD measurements differed between expanders, they were proportional to the activation of the appliances (IBaD). The increase in the IApD measurement was proportionally greater in the group treated with the tooth-borne expander (0.7:1.0) than in that treated with the tooth-tissue-borne expander (0.4:1.0). It was concluded that both appliances had similar effects, although the tooth-tissue-borne expander produced a lesser opening at the apical region of the incisors.

Skeletal and dental components of Class II correction with the bionator and removable headgear splint appliances

The purpose of this study was to differentiate the dentoalveolar and skeletal effects to better understand orthodontic treatment. We evaluated the treatment changes associated with the bionator and the removable headgear splint (RHS). Methods: The sample comprised 51 consecutively treated Class II patients from 1 office who had all been successfully treated with either a bionator (n = 17) or an RHS appliance (n = 17). Class II patients waiting to start treatment later served as controls (n = 17). A modified version of the Johnston pitchfork analysis was used to quantify the dentoalveolar and skeletal contributions to the anteroposterior correction at the levels of the molars and the incisors. Results: Both appliances significantly improved anteroposterior molar relationships (2.15 mm for the bionator, 2.27 mm for the RHS), primarily by dentoalveolar modifications (1.49 and 2.36 mm for the bionator and the RHS, respectively), with greater maxillary molar distalization in the RHS group. Overjet relationships also improved significantly compared with the controls (3.11 and 2.12 mm for the bionator and the RHS, respectively), due primarily to retroclination of the maxillary incisors (2.2 and 2.38 mm for the bionator and the RHS, respectively). The differences between overall corrections and dentoalveolar modifications for both molar and overjet relationships were explained by skeletal responses, with the bionator group showing significantly greater anterior mandibular displacement than the RHS group. Conclusions: The bionator and the RHS effectively corrected the molar relationships and overjets of Class II patients primarily by dentoalveolar changes. (Am J Orthod Dentofacial Orthop 2008; 134: 732-41)

Comparative study of the Frankel (FR-2) and bionator appliances in the treatment of Class II malocclusion

The purpose of this investigation was to compare the dentoalveolar and skeletal cephalometric changes produced by the Frankel (FR-2) and bionator appliances in persons with Class 11 malocclusion. Lateral cephalograms were available for 66 patients of both sexes, who were divided into 3 groups of 22. The control group included untreated Class 11 children, with an initial mean age of 8 years 7 months; they were followed without treatment for 13 months. The FR-2 appliance group had an initial mean age of 9 years; those children were treated for a mean period of 17 months. The bionator group initially had a mean age of 10 years 8 months; on average, they were treated for 16 months. The results demonstrated no significant changes in maxillary growth during the evaluation period. Both appliances showed statistically significant increases in mandibular growth and mandibular protrusion, with greater increases in patients treated in the bionator group. Both experimental groups showed an improvement in the maxillomandibular relationship. There were no significant changes in growth direction, while the bionator group had a greater increase in posterior facial height. Both appliances produced similar labial tipping and protrusion of the lower incisors, lingual inclination, retrusion of the upper incisors, and a significant increase in mandibular posterior dentoalveolar height. The major treatment effects of bionator and FR-2 appliances were dentoalveolar, with a smaller, but significant, skeletal effect.

Effects of cervical headgear and edgewise appliances on growing patients

Maxillary basal bone, dentoalveolar, and dental changes in Class II Division 1 patients treated to normal occlusion by using cervical headgear and edgewise appliances were retrospectively evaluated. A sample of 45 treated patients was compared with a group of 30 untreated patients. Subjects were drawn from the Department of Orthodontics, Araraquara School of Dentistry, Brazil, and ranged in age from 7.5 to 13.5 years. The groups were matched based on age, gender, and malocclusion. Roughly 87% of the treated group had a mesocephalic or brachicephalic pattern, and 13% had a dolicocephalic pattern. Cervical headgear was used until a Class I dental relationship was achieved. Our results demonstrated that the malocclusions were probably corrected by maintaining the maxillary first molars in position during maxillary growth. Maxillary basal bone changes (excluding dentoalveolar changes) did not differ significantly between the treated and the untreated groups. Molar extrusion after the use of cervical headgear was not supported by our data, and this must be considered in the treatment plan of patients who present similar facial types. (Am J Orthod Dentofacial Orthop 2001;119:531-9).