103 research outputs found
Bioactive glass added to autogenous bone graft in maxillary sinus augmentation: a prospective histomorphometric, immunohistochemical, and bone graft resorption assessment
Objective: The aim of this study was to compare the bone resorption rate, histomorphometry and immunohistochemical findings of bioactive glass (Biogran; Biomet, Warsaw, IN, USA) mixed with autogenous bone grafts (1:1) and autogenous bone graft isolate in maxillary sinus elevation surgery. Material and Methods: A total of 9 maxillary sinuses were grafted with Biogran with autogenous bone graft (group 1) and 12 were mixed with autogenous bone graft (group 2). Postoperative cone beam computed tomography (CBCT) was used to measure the initial graft volume after 15 days (T1), and 6 months later, another CBCT scan was performed to evaluate the final graft volume (T2) and determine the graft resorption rate. The resorption outcomes were 37.9%±18.9% in group 1 and 45.7%±18.5% in group 2 (P=0.82). After 6 months, biopsies were obtained concurrent with the placement of dental implants; these implants were subjected to histomorphometric analysis and immunohistochemical analysis for tartrate-resistant acid phosphatase (TRAP). Results: The average bone formation in group 1 was 36.6%±12.9 in the pristine bone region, 33.2%±13.3 in the intermediate region, and 45.8%±13.8 in the apical region; in group 2, the values were 34.4%±14.4, 35.0%±13.9, and 42.0%±16.6 of new bone formation in the pristine bone, intermediate, and apical regions, respectively. Immunostaining for TRAP showed poor clastic activity in both groups, which can indicate that those were in the remodeling phase. Conclusions: The similarity between the groups in the formation and maintenance of the graft volume after 6 months suggests that the bioactive glass mixed with autogenous bone (1:1) can be used safely as a bone substitute for the maxillary sinus lift
Deep Venous Thrombosis Prophylaxis In Oral And Maxillofacial Surgery: A Brazilian Survey.
Deep venous thrombosis (DVP) is a frequent disease. Prophylaxis is the best means to reduce its incidence, for lowering morbidity and mortality rates and treatment costs caused by its complications. To evaluate the knowledge and use of any kind of DVT prophylaxis by Brazilian Oral and Maxillofacial surgeons. A questionnaire was sent to all Oral and Maxillofacial surgeons associated to the Brazilian College of Oral and Maxillofacial Surgeons that have a valid e-mail address. The data retrieved was evaluated and tabulated. Of the 1100 questionnaires sent, only 4% were retrieved. The 42 retrieved were included in the study. Twenty six of the surgeons do not use any kind of deep venous thrombosis (DVT) prophylaxis, 11 use mechanical means as elastic compressive stockings or pneumatic compressive devices for prophylaxis, and 5 uses low-molecular weight heparins (LMWH) as the choice for prophylaxis. The data collected, despite the low rate of participation (4%) by the surgeons, shows that this subject still does not receive proper attention. Whereas other medical specialties make routine use of prophylactic means maybe the maxillofacial surgeons lack concern on that matter.23519-2
Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats
Although the search for the ideal bone substitute has been the focus of a large number of studies, autogenous bone is still the gold standard for the filling of defects caused by pathologies and traumas, and mainly, for alveolar ridge reconstruction, allowing the titanium implants installation. OBJECTIVES: The aim of this study was to evaluate the dynamics of autogenous bone graft incorporation process to surgically created defects in rat calvaria, using epifluorescence microscopy. MATERIAL AND METHODS: Five adult male rats weighing 200-300 g were used. The animals received two 5-mm-diameter bone defects bilaterally in each parietal bone with a trephine bur under general anesthesia. Two groups of defects were formed: a control group (n=5), in which the defects were filled with blood clot, and a graft group (n=5), in which the defects were filled with autogenous bone block, removed from the contralateral defect. The fluorochromes calcein and alizarin were applied at the 7th and 30th postoperative days, respectively. The animals were killed at 35 days. RESULTS: The mineralization process was more intense in the graft group (32.09%) and occurred mainly between 7 and 30 days, the period labeled by calcein (24.66%). CONCLUSIONS: The fluorochromes showed to be appropriate to label mineralization areas. The interfacial areas between fluorochrome labels are important sources of information about the bone regeneration dynamics
An encoderless high-performance synchronous reluctance motor drive
This paper presents an encoderless high-performance synchronous reluctance motor drive for traction applications. The control system is based on the active flux concept and a hybrid rotor position estimation algorithm is used, being this algorithm based on the injection of high-frequency signals at low speeds and on the position of the active flux vector for medium and high-speeds. A smooth transition algorithm between the two rotor position estimation methods is provided. Moreover, in order to improve the efficiency of the overall drive system, a loss minimization algorithm is proposed in order to reduce the motor copper losses when operating in steady-state. Experimental results obtained in the laboratory confirm the validity and adequacy of the proposed algorithms for the developed drive system.info:eu-repo/semantics/publishedVersio
The new bone formation in human maxillary sinuses using two bone substitutes with different resorption types associated or not with autogenous bone graft: a comparative histomorphometric, immunohistochemical and randomized clinical study
Objective: The aim of this study is to evaluate the new bone and connective tissue formation and the biomaterial remaining after maxillary sinus bone augmentation using 5 different bone substitutes. The osteocalcin immunolabeling was performed to demonstrate their calcification and the possibility of receiving dental implants. Methodology: 40 patients underwent maxillary sinus bone augmentation and were divided in 5 groups: Group 1 with 8 maxillary sinuses were grafted with autogenous bone graft (AB); Group 2 with 8 maxillary sinuses grafted with bioactive glass (BG); Group 3 with 8 maxillary sinuses grafted with bioactive glass added to autogenous bone graft (BG + AB) 1:1; Group 4 with 8 maxillary sinuses grafted with Bio-Oss (BO) and Group 5 with 8 maxillary sinuses grafted with Bio-Oss added to autogenous bone graft (BO + AB) 1:1. Results: In group AB, 37.8% of bone was formed in the pristine bone region, 38.1% in the intermediate and 44.5% in the apical region. In group BG, 43.6% was formed in the pristine bone, 37% in the intermediate and 49.3% in the apical region. In group BG + AB 1:1, 39.0% was formed in the pristine bone region, 34.8% in the intermediate and 36.8% in apical region. In group BO, 33.4% was formed in the pristine bone, 32.5% in the intermediate and 34.3% in the apical region. In group BO + AB 1:1, 32.8% was formed in the pristine bone, 36.1% in intermediate and 27.8% in the apical regions. The immunolabeling for osteocalcin showed an intensive staining for all groups, which could demonstrate the calcification of the bone formed. Conclusion: This study showed that the groups evaluated formed a suitable lamellar bone in the maxillary sinus reconstruction after six months of bone healing, thus being indicated to receive dental implants.
 
Carcinoma Mucoepidermóide de Glândula Sublingual: Relato de Caso Clínico
The major salivary glands tumors are 3 to 5 % of all the head and neck neoplasms. The mucoepidermoid carcinoma is a malignant tumor of salivar gland most frequent in the oral cavity, preferential in females, between 3 th and 4th decades of life. One is about an aggressive injury, where the main clinical aspects include a nodular form, solid and fixed consistence increase the touch, varying among the blue shades to the red or purple. The process diagnosis is made through an association among the clinical and complemental exams, being the biopsy essential for the dignosis conclusion. The mucoepidermoid carcinoma can be classified as his differentiation degree in low, intermediate and high-grade. A recent system using five histopathological founds seems to be the ideal to accomplish that classification. Treatment usually surgical, include complete resection of the lesion, being the favorable prognostic.Os tumores das glândulas salivares maiores correspondem a aproximadamente 3 a 5% de todas as neoplasias da cabeça e pescoço. O carcinoma mucoepidermóide (CME) é o tumor maligno de glândula salivar mais frequente na cavidade bucal, ocorrendo preferencialmente no gênero feminino, entre a 3º e 4º décadas de vida. Trata-se de uma lesão agressiva, que se apresenta clinicamente por meio de um aumento de volume com aspecto nodular, de consistência sólida, fixo à palpação, variando entre as tonalidades de azul, vermelho ou púrpura. O processo diagnóstico é feito por meio de uma associação entre os exames clínico e complementar, sendo a biópsia essencial para a sua conclusão. O carcinoma mucoepidermóide pode ser classificado quanto ao seu grau de diferenciação em baixo, intermediário e alto grau. Um recente sistema utilizando cinco achados histopatológicos parece ser o ideal para realizar essa classificação. O tratamento é cirúrgico e consiste em exérese total da lesão, sendo o prognóstico favorável
Lesão queratocística em arco central mandibular. Uma região incomum
O tumor queratocístico odontogênico (TOQ), anteriormente conhecido como queratocisto odontogênico, tem características únicas, incluindo comportamento localmente agressivo, alta taxa de recorrência e aparência histológica distinta. O TOQ é uma das neoplasias odontogênicas mais comuns da mandíbula, representando cerca de 12 e 14% de todos os quistos odontogênicos das mandíbulas. Seu comportamento apresenta potencial de destruição local e extensão em tecidos, crescimento rápido, maior taxa de recorrência e uma tendência à multiplicidade. Embora várias terapias para o TOQ tenham sido documentadas na literatura, a abordagem aceita permanece indecisa. Estas variam desde métodos conservadores, como enucleação, descompressão e marsupialização, até tratamentos agressivos que incluem ostectomia periférica, crioterapia, aplicação da solução de Carnoy e ressecção da mandíbula. Todas as técnicas têm objetivos similares: a erradicação do cisto e a redução dos riscos de recidiva e morbidade cirúrgica. Este artigo tem como objetivo relatar um caso de TOQ na região anterior da mandíbula e discutir os principais métodos de tratamento cirúrgico descritos na literatura
Bone regeneration in surgically created defects filled with autogenous bone: an epifluorescence microscopy analysis in rats
Cisto dentígero: modalidades de tratamento
INTRODUCTION: The dentigerous cyst is the second most common odontogenic cyst in the jaws. It is a benign lesion of odontogenic epithelium derived from the crown of a tooth that has not erupted, but of uncertain etiology. They are generally radiolucent and usually unilocular. These lesions are observed in routine examinations or when the eruption of a permanent tooth is delayed. The third molars and maxillary canines are the most affected teeth, and also the high occurrence of this lesion is associated with supernumerary teeth and odontomas. The dentigerous cyst occurs mainly in the first three decades of life, It's growth is slow, asymptomatic and can reach considerable size causing facial deformity, displacement and impaction of teeth and/or surrounding structures. OBJECTIVE: Definition of marsupialization and enucleation techniques as well as consideration of important objective criteria for the treatment plan like cyst size, age, proximity to anatomical structures and clinical importance of the involved tooth. Despite the clinical peculiarities of each case and the chosen treatment method, the prognosis of these lesions are favorable when appropriate therapy is used. MATERIAL AND METHOD: This study will present a case report treated by maneuver of decompression followed by enucleation and discussion of treatment modalities. RESULT: The patient is on two years of postoperative without signs of relapse and absence of paresthesias in the face. CONCLUSION: The technique preserved the neurosensory function and was effective for the extinction of the lesion.INTRODUÇÃO: O cisto dentígero é o segundo cisto odontogênico mais frequente nos maxilares. É uma lesão benigna, derivada do epitélio odontogênico da coroa de um dente não erupcionado, porém de etiopatogenia incerta. São geralmente radiotransparentes e, mais comumente, uniloculares. Estas lesões são observadas em exames de rotina ou quando não ocorre o irrompimento de um dente permanente. Os terceiros molares inferiores e os caninos superiores são os dentes mais acometidos, sendo também alta a ocorrência desta lesão em dentes supranumerários e associados a odontomas. O cisto dentígero ocorre principalmente nas três primeiras décadas de vida, tendo um crescimento lento e assintomático; pode atingir dimensões consideráveis, causando deformidade facial, impactação e deslocamento de dentes e/ou estruturas adjacentes. OBJETIVO: Definição das técnicas de marsupialização e enucleação, bem como consideração de critérios objetivos importantes para o plano de tratamento, como tamanho do cisto, idade, proximidade com estruturas anatômicas e importância clínica do dente envolvido. Apesar das peculiaridades clínicas de cada caso e do método de tratamento escolhido, o prognóstico destas lesões é favorável, quando se emprega apropriada terapêutica. MATERIAL E MÉTODO: O presente estudo apresentará um relato de caso tratado através da manobra de descompressão seguida de enucleação, bem como uma discussão acerca das modalidades de tratamento. RESULTADO: O paciente encontra-se em pós-operatório de dois anos sem sinais de recidiva da lesão e ausência de parestesias em face. CONCLUSÃO: A técnica empregada preservou a função neurossensorial e mostrou-se eficiente para a cura da lesão.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
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