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ABSTRACT Objective: Evaluate the biomechanical behavior of the influence of different internal angles of conical prosthetic connections in fixed partial prostheses of three elements, through the tridimensional finite element method. Methods: Two different models of segment of the posterior portion of the mandible, with two implants with conical connections at angulations of 11.5 and 16 degrees. Afterwards, and occlusal load of 180N was used, and divided into 2 points of application on the premolar, and 400N divided into 5 points of application on the molar. Data were acquired as the tensile, compressive and shear stresses on cortical and medullary bone, and von Mises stresses on implants and prosthetic components of two implants in both in three-unit fixed partial prosthesis. In the quantitative analysis, both in cortical and medullary bone, the tension peaks in tensile, compression, and shear forces were higher for the CM16 group. Results: When analyzing qualitatively, the cortical and medullary bones presented a greater stress around the implant platform with a higher incidence in the implant in the molar region. In the von Misses analysis in both groups, the tensions were concentrated in the cervical region of the implants, in the first threads, in the premolar and molar regions. Regarding prosthetic pillars, the stress concentration was located in the region of contact with the implant. Conclusion: The increased angulation of conicity of the internal conical connections represents a determinant factor to increase in stress concentration in the implants, prosthetic components and adjacent structures, such as the cortical and medullary bone.
RESUMO Objetivo: Avaliar a influência das diferentes angulações internas de conexões protéticas cônicas em próteses parciais fixas de três elementos, em relação a distribuição de tensões no osso cortical e medular adjacente, também como nos implantes e componentes protéticos através do método dos elementos finitos. Métodos: Foram analisados de forma quantitativa e qualitativa, através do método de elementos finitos, as tensões de tração, compressão e cisalhamento no osso cortical e medular, e tensões de von Misses nos implantes e componentes protéticos de dois implantes, um com conexão cônica de 11.5 graus e o outro de 16 graus. Ambos em prótese múltipla de três elementos. Resultados: Na análise quantitativa, tanto no osso cortical quanto no medular, os picos de tensão nas forças de tração, compressão, e de cisalhamento foram maiores para o grupo CM16, se comparado ao CM11,5, exceto a força de cisalhamento do osso cortical, que obteve valores muito próximos em ambos os grupos. Ao se analisar qualitativamente, os ossos corticais e medulares apresentaram um maior stress ao redor da plataforma dos implantes com incidência maior no implante na região do molar. Na análise von Misses em ambos os grupos, as tensões concentraram-se na região cervical dos implantes, nas primeiras roscas, nas regiões de pré-molar e molar. No que diz respeito aos pilares protéticos, a concentração de tensões foi localizada na região de contato com o implante. Conclusão: Podemos concluir que conforme o ângulo da interface implante-pilar aumenta, ocorre uma incidência maior de tensões em todas as áreas envolvidas nesse estudo.
ABSTRACT
The effectiveness of dental implants in patients with disability, who are non-compliant during treatment, is controversial because of their poor oral health. Thus, oral health-care and management in such patients is concerning. Moreover, limited information is available on prognosis after implant placement. Herein, we describe a patient with schizophrenia who underwent dental implantation under multiple inductions of general anesthesia (5 times) and required conservative treatment and tooth extraction for multiple dental caries and retained roots because of inadequate oral health-care. Postoperatively, fracture of the prosthodontics and progression of dental caries were observed, and with 3 additional inductions of general anesthesia, conservative treatment, implant surgery, and prosthesis implantation were conducted. Postoperative 12-month follow-up since the last prosthesis implantation showed successful results. For patients with schizophrenia, multiple implantation can reduce horizontal bone loss and achieve aesthetic results compared to treatment with removable prosthodontics and could serve as an alternative treatment modality.
Subject(s)
Humans , Anesthesia, General , Dental Caries , Dental Implantation , Dental Implants , Follow-Up Studies , Oral Health , Prognosis , Prosthesis Implantation , Prosthodontics , Schizophrenia , Tooth ExtractionABSTRACT
Objective@#To investigate the computer-aided design(CAD) of enblock porous silicone prosthesis for forehead and temporal augmentation with endoscope technique.@*Methods@#The 3-dimensional image of the enblock porous silicone prosthesis for forehead and temporal augmentation was designed with the aid of computer based on the 3-D images, the metal model and silicone prosthesis were made for surgery guided by endoscope technique.@*Results@#20 cases underwent frontal and temporal augmentation with enblock protheis with primary healing. No complication, like infection, effusion, nerve injury, prothesis displacement, happened. The patients were followed up for half a year with satisfactory result .@*Conclusions@#CAD for enblock porous silicone prosthesis for forehead and temporal augmentation has the advantages of individual design and good adaptation. Endoscope technique can be effective for reduction of the complication, like bleeding and protheis displacement.
ABSTRACT
Alloplastic materials used for orbital fracture reconstruction can induce complications, such as infection, migration, extrusion, intraorbital hemorrhage, and residual diplopia. Silicone is one of the alloplastic materials that has been widely used for decades. The author reports a rare case of spontaneous extrusion of a silicone implant that was used for orbital fracture reconstruction 30 years earlier. A 50-year-old man was admitted to the emergency room for an exposed substance in the lower eyelid area of the left eye, which began as a palpable hard nodule a week earlier. The exposed material was considered to be implant used for previous surgery. Under general anesthesia, the implant and parts of the fibrous capsule tissue were removed. Several factors hinder the diagnosis of implant extrusions that occur a long period after the surgery. So, surgeons must be aware that complications with implants can still arise several decades following orbital fracture reconstruction, even without specific causes.
Subject(s)
Humans , Middle Aged , Anesthesia, General , Diagnosis , Diplopia , Emergency Service, Hospital , Eyelids , Hemorrhage , Orbit , Orbital Fractures , Orbital Implants , Postoperative Complications , Silicon , Silicones , SurgeonsABSTRACT
Alloplastic materials used for orbital fracture reconstruction can induce complications, such as infection, migration, extrusion, intraorbital hemorrhage, and residual diplopia. Silicone is one of the alloplastic materials that has been widely used for decades. The author reports a rare case of spontaneous extrusion of a silicone implant that was used for orbital fracture reconstruction 30 years earlier. A 50-year-old man was admitted to the emergency room for an exposed substance in the lower eyelid area of the left eye, which began as a palpable hard nodule a week earlier. The exposed material was considered to be implant used for previous surgery. Under general anesthesia, the implant and parts of the fibrous capsule tissue were removed. Several factors hinder the diagnosis of implant extrusions that occur a long period after the surgery. So, surgeons must be aware that complications with implants can still arise several decades following orbital fracture reconstruction, even without specific causes.
Subject(s)
Humans , Middle Aged , Anesthesia, General , Diagnosis , Diplopia , Emergency Service, Hospital , Eyelids , Hemorrhage , Orbit , Orbital Fractures , Orbital Implants , Postoperative Complications , Silicon , Silicones , SurgeonsABSTRACT
PURPOSE: The most important factor in longevity studies of dental prostheses is objective and consistent evaluation of the prosthesis. The Korean Academy of Prosthodontics suggested developing a standardized method for longevity studies of dental prostheses. The purpose of this study is to evaluate previously-used criteria and to develop new criteria, in the form of a procedure flowchart and an evaluation sheet. These new criteria may be able to provide a unified standard for future longevity studies of dental prostheses. MATERIALS AND METHODS: A literature review was performed about the evaluation of dental prostheses. Taking into account the strengths and weaknesses of previously used criteria, a novel, intuitive and objective method was developed for assessment of dental prostheses. Then, a pilot survey was performed with the newly developed flowchart and evaluation sheet to determine problems and implement possible improvements. RESULTS: Thirty cases of fixed dental prosthesis (FDP), 25 cases of removable dental prosthesis (RDP), and 13 cases of implant supported prosthesis (ISP) were evaluated. The average life expectancy estimate was 12.82 years for FDP, 5.96 years for RDP, and 4.82 years for ISP with Kaplan-Meier survival analysis. Additionally, possible improvements discovered by the pilot survey were reflected in the flowchart and evaluation sheet. CONCLUSION: The newly developed KAP criteria, flowchart and evaluation sheet enabled objective and consistent results in trial longevity studies of dental prostheses. It is expected that future studies will not only use the KAP criteria but also further improvement will be made on them.
Subject(s)
Data Collection , Dental Prosthesis , Kaplan-Meier Estimate , Korea , Life Expectancy , Longevity , Methods , Prostheses and Implants , Prosthodontics , Software Design , Survival RateABSTRACT
Mesenteric lymphangiomas, which involve near total mesentery, are extremely rare. A mesenteric lymphangioma should be treated through excision because they can cause invasion of vital structures, bleeding, or infection. After excision of a huge mesenteric lymphangioma, internal herniation may occur through a large mesenteric defect leading to intestinal volvulus, obstruction, and other life-threatening circumstances. We report a case in which a biologic collagen implant (Permacol) was used for mesenteric defect repair after excision of a huge mesenteric lymphangioma. The implant did not cause any symptoms or complications during follow-up for 4 years. When encountering large defects of mesentery, closure with implant can be a feasible choice, and Permacol could be a possible implant for closing the defect.
Subject(s)
Child , Humans , Collagen , Follow-Up Studies , Hemorrhage , Intestinal Volvulus , Lymphangioma , MesenteryABSTRACT
Background The dysfunction of the blink reflex the eyelid-closure ability appears in the patients with facial paralysis,and its management is the implantation of mechanical-assisted eye-closure device in the upper eyelid.A novel device is palpebral spring implant.However,there is no similar study in China.Objective This study was to evaluate the clinical efficacy of palpebral spring placement for lagophthalmos caused by facial nerve palsy.Methods This clinical research complied with Helsinki declaration and the protocol was approved by Ethic Committee of Henan Eye Institute & Henan Eye Hospital.Written informed consent was obtained from each patient prior to the surgery.A retrospective serial case-observational study was performed.The medical records of 11 patients who underwent palpebral spring placement for hypophasis due to facial nerve palsy were reviewed at Henan Eye Hospital from August 2010 to November 2012.Palpebral spring placement was performed by the same surgeon to ensure a more even outcomes.Palpebral spring was made by nickel wire,with the diameter of 0.3 mm and implanted on tarsal plate in 11 eyes of 11 patients with symptomatic facial nerve palsy.The lower tip of Levine spring was encased into a small terylene bag and sutured to the anterior tarsal surface during the surgery.Preoperative and postoperative symptoms,upper eyelid margin to mid pupil distance (ULMD),degree of lagophthalmos and eyelid moving scope were examined and compared between before and after operation.The operating complication was followed-up for 8-38 months.Results The discomforted symptoms disappeared in all the operated eyes.The ULMD was (3.51±0.73) mm in preoperation and (3.20±0.86) mm in posteration,without significant difference between them (t=1.36,P=0.10).The degree of lagophthalmos was (5.94±1.57) mm and (1.06±0.98) mm in preoperation and postoperation respectively,showing a significant difference between them (t =9.42,P =0.00).The eyelid moving scope was (5.89±0.70) mm in postoperation,which was significantly increased in comparison with (0.11 ±0.33) mm of preoperation (t =22.97,P =0.00).The palpebral spring implant was regulated in 1 patient during the follow-up duration due to the trauma.No complication in other 10 patients appeared during the follow-up duration,such as implant exposure,metal fatigue or infection.Conclusions Palpebral spring placement is safe and effective for lagophthalmos in patients with facial nerve palsy.
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Introdução: A cirurgia de aumento mamário foi a cirurgia plástica mais realizada no Brasil, em 2008. Com a evolução da técnica e da qualidade dos implantes de silicone, a taxa de complicações tem diminuído progressivamente, tornando a cirurgia mais segura. Objetivo: Demonstrar o perfil das pacientes submetidas à troca de implante mamário, nos últimos cinco anos, na Clínica Ivo Pitanguy, analisando as características dos implantes de silicone e as causas que motivaram a troca. Método: Foram analisadas, retrospectivamente, todas as pacientes submetidas a procedimentos cirúrgicos de troca, retirada ou reinclusão de implantes mamários, nos últimos cinco anos, num total de 59 pacientes em 68 procedimentos e 129 mamas operadas. Resultados: O intervalo de tempo entre a colocação e a retirada dos implantes variou de 1 mês a 34 anos; 44 pacientes eram provenientes do nosso serviço e 24 de outros. Quarenta e três implantes eram, antes da troca, de poliuretano, 13 texturizados e seis lisos. O grande motivo de troca foi estético, com 50 casos, seguido por contratura capsular em 13 casos, e cinco casos de infecção, ruptura ou nódulo mamário. Conclusão: O principal motivo de troca de implantes foi estético, diferentemente da literatura. Os índices de contratura capsular e de infecção da loja do implante do presente estudo foram comparáveis aos apresentados em vários outros estudos.
Background: The breast augmentation surgery was the most performed in Brazil in 2008. With the evolution of the technique and the quality of the implants, complications have diminished, leading to a more secure procedure. Objective: To assess the profile of patients submitted to implant exchange in the last five years at Ivo Pitanguy Clinic, analyzing the causes that led to implant removal. Methods: We have analyzed all patients submitted to exchange, removal or replacement of mammary implants in the last five years, at a total of 59 patients, 68 procedures and 129 breasts operated. Results: The time interval from the inclusion to the removal of the implants ranged from one month to 34 years; 44 patients have first operated at our service and 24 at other services. Forty three implants were, before the exchange, made of polyurethane, 13 texturized and six smooth. The major cause of the exchange was esthetic, with 50 cases, followed by capsular contracture, 13 cases and five cases of infection, rupture or breast nodule. Conclusion: The major reason of implants exchange was esthetic, differing from the literature. The capsular contracture and infection rates, at this study, were comparable to several others.