RESUMO
INTRODUCTION: Surgically assisted rapid palatal expansion (SARPE) has been the treatment of choice in subjects presenting skeletally mature sutures. OBJECTIVE: The purpose of this study was to analyze stress distribution and displacement of the craniofacial and dentoalveolar structures resulting from three types of palatal expanders with surgical assistance using a non-linear finite element analysis. MATERIAL AND METHODS: Three different palatal expanders were designed: Model-I (tooth-bone-borne type containing four miniscrews), Model-II (tooth-bone-borne type containing two miniscrews), and Model-III (bone-borne type containing four miniscrews). A Le Fort I osteotomy was performed, and a total of 5.0 mm palatal expansion was simulated. Nonlinear analysis (three theory) method (geometric nonlinear theory, nonlinear contact theory, and nonlinear material methods) was used to evaluate stress and displacement of several craniofacial and dentoalveolar structures. RESULTS: Regardless of the maxillary expander device type, surgically assisted rapid palatal expansion produces greater anterior maxillary expansion than posterior (ANS ranged from 2.675 mm to 3.444 mm, and PNS ranged from 0.522 mm to 1.721 mm); Model-I showed more parallel midpalatal suture opening pattern - PNS/ANS equal to 54%. In regards to ANS, Model-II (1.159 mm) and Model-III (1.000 mm) presented larger downward displacement than Model-I (0.343 mm). PNS displaced anteriorly more than ANS for all devices; Model-III presented the largest amount of forward displacement for PNS (1.147 mm) and ANS (1.064 mm). All three type of expanders showed similar dental displacement, and minimal craniofacial sutures separation. As expected, different maxillary expander designs produce different primary areas and levels of stresses (the bone-borne expander presented minimal stress at the teeth and the tooth-bone-borne expander with two miniscrews presented the highest). CONCLUSIONS: Based on this finite element method/finite element analysis, the results showed that different maxillary expander designs produce different primary areas and levels of stresses, minimal displacement of the craniofacial sutures, and different skeletal V-shape expansion.
Assuntos
Osteotomia , Técnica de Expansão Palatina , Humanos , Análise de Elementos FinitosRESUMO
ABSTRACT Introduction: Surgically assisted rapid palatal expansion (SARPE) has been the treatment of choice in subjects presenting skeletally mature sutures. Objective: The purpose of this study was to analyze stress distribution and displacement of the craniofacial and dentoalveolar structures resulting from three types of palatal expanders with surgical assistance using a non-linear finite element analysis. Material and Methods: Three different palatal expanders were designed: Model-I (tooth-bone-borne type containing four miniscrews), Model-II (tooth-bone-borne type containing two miniscrews), and Model-III (bone-borne type containing four miniscrews). A Le Fort I osteotomy was performed, and a total of 5.0 mm palatal expansion was simulated. Nonlinear analysis (three theory) method (geometric nonlinear theory, nonlinear contact theory, and nonlinear material methods) was used to evaluate stress and displacement of several craniofacial and dentoalveolar structures. Results: Regardless of the maxillary expander device type, surgically assisted rapid palatal expansion produces greater anterior maxillary expansion than posterior (ANS ranged from 2.675 mm to 3.444 mm, and PNS ranged from 0.522 mm to 1.721 mm); Model-I showed more parallel midpalatal suture opening pattern - PNS/ANS equal to 54%. In regards to ANS, Model-II (1.159 mm) and Model-III (1.000 mm) presented larger downward displacement than Model-I (0.343 mm). PNS displaced anteriorly more than ANS for all devices; Model-III presented the largest amount of forward displacement for PNS (1.147 mm) and ANS (1.064 mm). All three type of expanders showed similar dental displacement, and minimal craniofacial sutures separation. As expected, different maxillary expander designs produce different primary areas and levels of stresses (the bone-borne expander presented minimal stress at the teeth and the tooth-bone-borne expander with two miniscrews presented the highest). Conclusions: Based on this finite element method/finite element analysis, the results showed that different maxillary expander designs produce different primary areas and levels of stresses, minimal displacement of the craniofacial sutures, and different skeletal V-shape expansion.
RESUMO Introdução: A expansão rápida da maxila assistida cirurgicamente (ERMAC) tem sido o tratamento de escolha em indivíduos que apresentam suturas esqueleticamente maduras. Objetivo: O objetivo deste estudo foi avaliar, utilizando uma análise não linear com elementos finitos, a distribuição de tensões e os deslocamentos das estruturas craniofaciais e dentoalveolares gerados por três tipos de expansores palatinos usados na ERMAC. Material e Métodos: Três tipos de expansores palatinos foram projetados: Modelo I (dento-osseossuportado com quatro mini-implantes), Modelo II (dento-osseossuportado com dois mini-implantes) e Modelo III (osseossuportado com quatro mini-implantes). Uma osteotomia Le Fort I foi realizada e foi simulada uma expansão palatina total de 5,0 mm. Um método de análise não linear (três teorias - teoria da não-linearidade geométrica, teoria do contato não linear e métodos para materiais não lineares) foi utilizado para avaliar a tensão e o deslocamento de diversas estruturas craniofaciais e dentoalveolares. Resultados: Independentemente do tipo de aparelho expansor palatino, a ERMAC produziu maior expansão anterior da maxila do que posterior (ENA variou de 2,675 mm a 3,444 mm e ENP variou de 0,522 mm a 1,721 mm); o Modelo I apresentou padrão de abertura mais paralela da sutura palatina mediana, com ENP/ENA igual a 54%. Com relação à ENA, o Modelo II (1,159 mm) e o Modelo III (1,000 mm) apresentaram maior deslocamento para baixo do que o Modelo I (0,343 mm). A ENP deslocou-se mais para anterior do que a ENA com todos os aparelhos; o Modelo III apresentou o maior deslocamento para anterior da ENP (1,147 mm) e da ENA (1,064 mm). Os três tipos de expansores apresentaram deslocamento dentário semelhante e separação mínima das suturas craniofaciais. Como esperado, diferentes designs de expansores palatinos produzem diferentes áreas primárias e níveis de tensões (o expansor osseossuportado apresentou tensão mínima nos dentes, e o expansor dento-osseossuportado com dois mini-implantes apresentou o maior). Conclusões: Com base nesse estudo de elementos finitos, os resultados mostraram que diferentes designs de expansores palatinos produzem diferentes áreas primárias e níveis de tensão, com deslocamento mínimo das suturas craniofaciais e diferentes expansões esqueléticas em forma de V.
RESUMO
Background: Lameness results in major economic losses on dairy farms. The proportion of lameness in cows are between 4-55%, the origin of 90% lameness are caused by foot diseases. Hoof abnormalities such as laminitis are major contributors to lameness. Aim of the study, compared with thermographic imaging (IRT) and radiographic, magnetic resonans (MR), computer tomography (CT), histopathological analysis on the diagnosis of laminitis.Materials, Methods & Results: Preliminary, the animals (20 Holstein-Fresian) were selected by lameness examination for evaluation of the for any obvious signs of disease. The animals were examined when rising and walking of the free stalls. Walking was very painful and clinical symptoms of general distress become present for laminitic group. The cows were scored on a 1 to 5 scale for their locomotion (1 = normal locomotion; 5 = severely lame). Thermographic examinations were performed the all animals after the routine clinical examination methods. The infrared images were taken from the dorsal view of all hoovesto monitor the temperature of coronary band. All images were scanned using a hand-held portable infrared camera (Wahl, Thermal Imager HSI3000 Series), which was calibrated to ambient temperature and absorptive conditions. Incentives radiological examinations, dorso-palmar and latero-medial shooting was done for using of (Regius Model 110 Konica, Minolta) 70 kV and 30 mAs for each claws. MRI images of all isolated digits were performed at the Department of Radiology, by using Siemens Symphony Erlangen, Germany. Continuous series of transversal, sagital and dorsoplantar scan were obtained from all digit. Computer tomography (CT), isolated digits were performed at the Imaging Department of Radiology, by using Siemens Symphony Erlangen, Germany.[...](AU)
Assuntos
Animais , Bovinos , Casco e Garras/anatomia & histologia , Casco e Garras/fisiopatologia , Doenças do Pé/diagnóstico por imagem , Doenças do Pé/veterinária , Termografia/métodos , Tomografia Computadorizada por Raios X/métodos , Imageamento por Ressonância Magnética/métodosRESUMO
Background: Lameness results in major economic losses on dairy farms. The proportion of lameness in cows are between 4-55%, the origin of 90% lameness are caused by foot diseases. Hoof abnormalities such as laminitis are major contributors to lameness. Aim of the study, compared with thermographic imaging (IRT) and radiographic, magnetic resonans (MR), computer tomography (CT), histopathological analysis on the diagnosis of laminitis.Materials, Methods & Results: Preliminary, the animals (20 Holstein-Fresian) were selected by lameness examination for evaluation of the for any obvious signs of disease. The animals were examined when rising and walking of the free stalls. Walking was very painful and clinical symptoms of general distress become present for laminitic group. The cows were scored on a 1 to 5 scale for their locomotion (1 = normal locomotion; 5 = severely lame). Thermographic examinations were performed the all animals after the routine clinical examination methods. The infrared images were taken from the dorsal view of all hoovesto monitor the temperature of coronary band. All images were scanned using a hand-held portable infrared camera (Wahl, Thermal Imager HSI3000 Series), which was calibrated to ambient temperature and absorptive conditions. Incentives radiological examinations, dorso-palmar and latero-medial shooting was done for using of (Regius Model 110 Konica, Minolta) 70 kV and 30 mAs for each claws. MRI images of all isolated digits were performed at the Department of Radiology, by using Siemens Symphony Erlangen, Germany. Continuous series of transversal, sagital and dorsoplantar scan were obtained from all digit. Computer tomography (CT), isolated digits were performed at the Imaging Department of Radiology, by using Siemens Symphony Erlangen, Germany.[...]