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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

AVALIAÇÃO DA PROPORÇÃO DENTAL DE BOLTON EM INDIVÍDUOS COM OCLUSÃO NORMAL NATURAL E MALOCLUSÕES DE CLASSE I E CLASSE II DIVISÃO 1 DE ANGLE. / Assessment of Bolton´s dental ratio in Brazilians with normal occlusion and Class I and Class II division 1 Angle´s malocclusions.

Ricci, Ivan Delgado 06 October 2010 (has links)
Made available in DSpace on 2016-08-03T16:31:15Z (GMT). No. of bitstreams: 1 IVAN DELGADO RICCI.pdf: 1269802 bytes, checksum: 7496457c509408d4b688ae6ae2ae730f (MD5) Previous issue date: 2010-10-06 / Introduction: The Bolton analysis, analysis that quantifies the tooth size is an important reference for professionals seeking appropriate orthodontic finishing. Objective: The objective of this study is to verify that there is discrepancy between the subjects with normal occlusion and malocclusion Class I and Class II division 1 belonging to the selected sample, compared to the values reported by Bolton and also check difference related to sexual dimorphism. Methods: 3 groups of 35 pairs of plaster casts each, separated by the type of occlusion, pertaining to the program of graduate orthodontics at the Methodist University of Sao Paulo were measured with a digital caliper at its greatest distance mesiodistal since 1st right molar to 1st molar left, the upper and lower arches, with permanent teeth. The values were tabulated and the proportion of Bolton has been applied. Results: Respectively for groups 1, 2 and 3, the total ratio found was 90.36 (SD ± 1.70), 91.17 (SD ± 2.58) and 90.76 (SD ± 2.45) and the anterior ratio was 77.73 (SD ± 2.39), 78.01 (SD ± 2.66) and 77.30 (SD ± 2.65). Conclusion: there was no sexual dimorphism or statistically significant difference compared to the values suggested by Bolton. / Introdução: A análise de Bolton, análise que quantifica o tamanho dentário, é uma referência importante para profissionais que buscam finalizações ortodônticas adequadas. Objetivo: O objetivo deste trabalho é verificar se há discrepância entre os indivíduos com oclusão normal natural e maloclusões de Classe I e de Classe II divisão 1 de Angle pertencentes a amostra selecionada, em relação aos valores encontrados por Bolton, bem como verificar também se há dimorfismo sexual. Metodologia: 3 grupos contendo 35 pares e modelos em gesso cada, separados pelo tipo de oclusão, pertencentes ao acervo do programa de pós-graduação em Ortodontia da Universidade Metodista de São Paulo foram medidos com paquímetro digital em sua maior distância mésiodistal desde 1º molar direito a 1º molar esquerdo, dos arcos superiores e inferiores, com dentição permanente. Os valores foram tabulados e a proporção de Bolton foi aplicada. Resultados: Respectivamente para os grupos 1, 2 e 3, a proporção total encontrada foi de 90,36 (DP±1,70), 91,17 (DP±2,58) e 90,76 (DP±2,45), e a proporção anterior foi de 77,73 (DP±2,39), 78,01 (DP±2,66) e 77,30 (DP±2,65). Conclusão: não houve dimorfismo sexual nem diferença estatisticamente significante comparando os valores aos sugeridos por Bolton.
182

Estudo da repetibilidade de manobras para o registro da relação cêntrica após a aplicação da ULF-TENS, por meio da Análise Eletrônica de Posição (EPA) / Study of the repeatability of centric relation registration techniques after the application of ULF-TENS by means of Electronic Position Analysis (EPA)

Rafaella Mariana Fontes de Bragança 04 February 2016 (has links)
A relação cêntrica (RC) é uma posição de grande importância no diagnóstico e tratamento em diversas áreas odontológicas. Durante a manipulação em RC, é importante impedir que a memória neuromuscular conduza a um registro incorreto. A neuroestimulação elétrica transcutânea de ultra baixa frequência (ULF-TENS) reduz a atividade eletromiográfica de músculos da mastigação. Desta forma, o presente estudo avaliou a influência da ULF-TENS no deslocamento da cabeça da mandíbula e na repetibilidade das técnicas de manipulação em RC (Bimanual de Dawson, tiras de Long e sistema R.O.C.A), além de verificar qual destas técnicas apresenta maior variabilidade. Para isso, 25 participantes sem Disfunção Temporomandibular (DTM) foram submetidos à duas etapas do estudo realizadas por meio da análise eletrônica de posição (EPA), que permite a avaliação da posição condilar em três eixos (X, Y e Z). Na primeira (ST), foram feitas três sequências com três registros de RC cada, um por técnica de manipulação. Na segunda (CT), foi aplicada a ULF-TENS por 30 minutos antes das sequências de registros, também realizada por três vezes. Utilizou-se o Mann-Whitney (p ≤ 0,05) para verificar a influência da ULF-TENS no deslocamento total para as técnicas Bimanual de Dawson, tiras de Long e sistema R.O.C.A e o ICC e 1-tailed F test a fim de avaliar a repetibilidade e a variância, respectivamente, dessas técnicas. A utilização da ULF-TENS não influenciou no deslocamento total da cabeça da mandíbula, independentemente da técnica de registro de RC utilizada (p>0,05). Apenas a técnica Bimanual apresentou uma melhora na repetibilidade com o uso da ULF-TENS, que foi restrita aos eixos X e Y direitos. Na comparação da variância entre as técnicas, a Bimanual demonstrou menor variação no eixo X, a de Long e R.O.C.A variaram menos no eixo Y e a de Long novamente teve menor variação no eixo Z. Pode-se concluir que o uso da ULF-TENS não altera o posicionamento condilar e melhora, embora discretamente, a repetibilidade apenas da técnica Bimanual. No geral, a técnica de Long apresentou menor variabilidade entre os participantes. / Centric relation (CR) is a position of great importance in diagnosis and treatment for several dental specialties. When guiding the jaw to CR, it is important to prevent the neuromuscular memory to mislead the record. Ultra low frequency-transcutaneous electrical nerve stimulation (ULF-TENS) reduces the electromyographic activity of masticatory muscles. Thus, the current study evaluated the influence of ULF-TENS in the displacement of the mandibular condyle and in the repeatability of centric relation registration techniques (Bimanual manipulation, Long technique, R.O.C.A. wires). In addition it was verified which of these techniques presents greater variability. For this purpose, 25 participants without Temporomandibular disorder (TMD) underwent two study stages conducted via electronic position analysis (EPA), which allows the evaluation of condylar position in three axes (X, Y e Z). In the first stage (NT), three sequences were made with three CR records each, one for manipulation technique. In the second stage (WT), the ULF-TENS was applied for 30 minutes before the record sequences, also performed for three times. Mann-Whitney test (p ≤ 0.05) was used to check the ULF-TENS influence on total displacement for Bimanual manipulation, Long technique and R.O.C.A. wires. ICC and 1-tailed F test were applied to assess the repeatability and variance, respectively, of these same techniques. Application of ULF-TENS did not influence the condyle total displacement, regardless of RC recording technique used (p> 0.05). Only Bimanual technique showed an improvement in repeatability with the use of ULF-TENS, which was restricted to the X and Y right axes. Concerning the variance comparison between the techniques, Bimanual manipulation showed less variation in the X axis, Long technique and R.O.C.A. wires varied less in the Y axis and Long technique was again less variable in the Z axis. It could be concluded that the use of ULF-TENS does not affect the condylar positioning and improved, although slightly, only the repeatability of Bimanual manipulation. Overall, Long technique presented lower variability among participants.
183

Avaliação das guias condilar e incisal em função da curva de compensação e da altura das cúspides - Releitura das Leis de Articulação de Hanau / Evaluation of condylar guidance and incisal guidance according to the compensating curve and cusp heights. A review of Hanaus laws of articulation

Roger Nishyama 19 April 2011 (has links)
Este estudo teve como objetivo avaliar a variação das guias sagitais (guia condilar e guia incisal), em função do plano de orientação (curvatura e inclinação) e da altura das cúspides, no movimento protrusivo mandibular, in vitro, buscando as relações entre esses fatores, tanto de forma analógica como digital. No estudo analógico foram avaliadas as inclinações das guias condilares, inclinações da guia incisal, proeminência da curva de compensação e inclinação do plano oclusal. Para isso foram utilizados planos de orientação prototipados com a proeminência da curva de compensação pré definidas por calotas de esferas de 7, 8 ou 9 polegadas de diâmetro. Para cada proeminência da curva de compensação haviam 3 inclinações antero-posterior também pré definidas em: planos iniciais, ou planos 0, planos com um aumento da inclinação de 5 graus em relação ao primeiro, ou plano +5, e planos com uma inclinação 5 graus menor que o primeiro, ou plano -5. Com um par planos de orientação montados no articulador não arcon Bio-art EVA Plus ajustou-se as guias condilares e incisal, após isso foi aumentada a inclinação da guia condilar e observadas as alterações necessárias nos outros três fatores, inclinação da guia incisal, proeminência da curva de compensação e inclinação do plano oclusal, cada uma em seu determinado momento, para se restabelecer o ajuste do articulador. Esse procedimento foi repetido alterando-se cada um dos outros 3 fatores gerando assim 6 condições experimentais analógicas. No estudo digital foram avaliadas as inclinações das guias condilares, inclinações da guia incisal, proeminência da curva de compensação, inclinação do plano oclusal e altura das cúspides dos dentes posteriores. Para isso, o articulador Bio-art EVA Plus foi reproduzido no programa Adobe Photoshop CS3 juntamente com os planos de orientação e as simulações de cúspides e de dentes anteriores. Da mesma forma que o estudo analógico iniciou-se com os planos de orientação em posição e o articulador com as guias condilares e guia incisal ajustadas; foi aumentada a inclinação da guia condilar e observado no movimento de protrusão o comportamento dos outros 4 fatores, cada um em um determinado momento, para o restabelecimento da oclusão bilaterla balanceada. Esse procedimento foi repetido com cada um dos outros 4 fatores gerando assim 10 condições experimentais virtuais. Os resultados permitiram concluir que existe uma relação entre a inclinação da guia condilar, inclinação da guia incisal, proeminência da curva de compesação, inclinação da curva de compensação e altura das cúspides, na obtenção da oclusão bilateral balanceada, e esta relação comprova as descritas por Hanau em seus estudos. / The objective of this in vitro study was to evaluate the variation of the saggital guidances (condylar guidance and incisal guidance) according to plane of orientation (prominence and inclination) and cusp heights during mandibular protrusive movements. The relationship between afore mentioned factors were assessed through both analogical and digital methods. In the analogical study, the inclination of condylar guidance and incisal guidance, prominence of compensating curve and the inclination of the occlusal plane were evaluated. In order to do so, prototyped guiding planes with compensating curves prominence pre-defined by spheres of 7, 8 and 9 inches of diameter were used. For each compensating curves prominence, there were also 3 pre-defined antero-posterior inclinations: initial planes (plane 0), planes with a 5-degree inclination increase (plane +5) and planes with a 5-degree inclination decrease (plane -5). A pair of guiding planes was mounted on a non-arcon Bio-art EVA Plus articulator and condylar and incisal guidances were adjusted. As the condylar guidance was increased, the changes necessary to reestablish the articulators adjustment were observed for the other three factors: incisal guidances inclination, prominence of compensating curve and occlusal planes inclination. This procedure was repeated altering each one of the other three factors resulting in 6 analogical experimental conditions. In the digital study, condylar guidance inclination, incisal guidance inclination, compensating curve prominence, occlusal plane inclination and posterior teeths cusp heights were evaluated. In order to do so, the Bio-art EVA Plus articulator, guiding planes and simulations of the cusps and anterior teeth were reproduced in the Adobe Photoshop CS3 program As performed at the analogical study, the guiding planes were put into position and the condylar and incisal guidances were adjusted. The condylar guidance inclination was increased and the changes in the other 4 factors were observed in the protrusive moment so that the bilateral balanced occlusion could be reestablished. This procedure was repeated with each one of the 4 factors resulting in 10 virtual experimental conditions. The results showed that there is a relationship between the condylar guidance inclination, incisal guidance inclination, prominence of the compensating curve and the cusp heights when achieving bilateral balanced occlusion and the results obtained in the current study is in accordance with those obtained by Hanau.
184

Modelos computacionais para análise da influência de parâmetros estatísticos de textura superficial no contato dentário humano

Oliveira, Evelyn Aparecida de 01 April 2016 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-02-13T14:23:53Z No. of bitstreams: 1 evelynaparecidadeoliveira.pdf: 4026204 bytes, checksum: c1b720f3501ffcd12b38f9d4c877dfa9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-02-13T16:49:50Z (GMT) No. of bitstreams: 1 evelynaparecidadeoliveira.pdf: 4026204 bytes, checksum: c1b720f3501ffcd12b38f9d4c877dfa9 (MD5) / Made available in DSpace on 2017-02-13T16:49:50Z (GMT). No. of bitstreams: 1 evelynaparecidadeoliveira.pdf: 4026204 bytes, checksum: c1b720f3501ffcd12b38f9d4c877dfa9 (MD5) Previous issue date: 2016-04-01 / O desgaste do dente, que se manifesta com uma grande variedade de graus ou níveis, é uma das anomalias dentárias comumente encontradas em diversas populações. A modelagem computacional do problema de contato oclusal pode ajudar na compreensão das interações entre os dentes, que gera concentrações de tensões. A abordagem utilizada para simular o contato entre as superfícies ásperas, dadas as funções de densidade de probabilidade das alturas das asperezas, consiste em discretizá-las em vários intervalos, de modo que cada um deles represente uma aspereza principal. As deformações das asperezas principais são analisadas e, utilizando técnicas de homogeneização, é possível estabelecer a relação entre as respostas que ocorrem em microescala e as respostas esperadas na macroescala. Neste trabalho, foi criada uma rotina para geração numérica de superfícies, um script acoplado ao programa de elementos finitos, Abaqus, para análise dos microcontatos, e, finalmente, um código para o procedimento de homogeneização e análise paramétrica das medidas de rugosidade. Na estimativa da dureza superficial, verificou-se que a curvatura média das asperezas exerce maior influência. Os parâmetros que mais influenciam nas forças e áreas de contato são o coeficiente de achatamento (kurtosis), cujo aumento leva ao decaimento dessas grandezas, seguido da rugosidade média quadrática, que, por sua vez, tem uma relação diretamente proporcional com a carga e consequentemente com a área de contato. / Tooth wear, which manifests with a great variety of degrees or levels, is one of the dental abnormalities commonly found in different populations. The computational modelling of the occlusal contact problem can help the comprehension of any interaction between teeth generating stress concentration. The approach used in this work to simulate contact between rough surfaces, given the probability density functions of asperities, consists in discretizing them in several intervals, so that each one represents a main asperity. The deformations of the main asperities are analyzed and, using homogenization techniques, it is possible to developed the relationship among the responses occurred in micro-scale and the predicted responses in macro-scale. In this work a routine has been established for numerical generation of surfaces, a script as well as has been coupled to the finite element program Abaqus, for analysis of the micro-contacts, and, finally, a code for homogenization and parametric analysis of the roughness measure. In the estimate of the surface hardness it was found that the mean curvature of the asperities exerts the largest influence. The parameters that influence the forces and contact areas are the flattening coefficient (kurtosis), which when increases leads to decay of these greatness, followed by the mean square roughness, which, in turn, has a direct proportional relationship with the strength and consequently with the contact area.
185

Childhood sleep-disordered breathing – dentofacial and pharyngeal characteristics

Pirilä-Parkkinen, K. (Kirsi) 29 November 2011 (has links)
Abstract The aim of this work was to examine distinct dentofacial and pharyngeal features in children with sleep-disordered breathing (SDB). A further aim was to test the validity of the conventional methods used in orthodontics for recognition of obstructed airways. Seventy children (36 girls, 34 boys, age range 4.2–11.9 years), who were diagnosed as having SDB during the years 2000–2002, constituted the source of subjects for four separate studies. The study protocol included otorhinolaryngological and orthodontic examinations. Dental impressions and lateral cephalograms were taken. In addition, upper airway was imaged in 36 children in different head postures by magnetic resonance imaging (MRI). Age- and gender-matched healthy children were used as controls. The results showed that children with SDB had increased overjet, smaller overbite, narrower upper and shorter lower dental arches and higher incidence of anterior open bite and distal molar relationship when compared with control children. The severity of the obstruction correlated with larger deviations from normal in the dental characteristics. There were more children with crowding and with anterior open bite with increased severity of the disorder. Children with SDB displayed an increased sagittal jaw relationship, a more vertical growth pattern of the mandible, a longer and thicker soft palate, a lower hyoid bone position, larger craniocervical angles and narrower pharyngeal airway measured at multiple levels, when compared with the controls. Deviation in pharyngeal variables showed highest correlation with the severity of SDB. MRI indicated a smaller than normal oropharyngeal airway in children with SDB. The effect of head posture on pharyngeal airway dimensions differed in children with SDB when compared with the controls. These findings verify that the developmental course of occlusal characteristics and craniofacial structures may be modulated by breathing pattern, and, on the other hand, that certain features may predispose to the development of the disorder. It is important to recognize these signs in order to guide further development in a more favorable direction. The results confirmed that cephalometry is a valid screening tool when assessing nasopharyngeal and retropalatal airway dimensions. Clinical examination of tonsillar size was found reliable when retroglossal airway size was evaluated. / Tiivistelmä Väitöskirjatyön tarkoituksena oli selvittää lasten unenaikaisten hengityshäiriöiden yhteyttä kasvojen ja leukojen kasvuun, purennan kehitykseen sekä ylempien hengitysteiden rakenteeseen. Lisäksi tutkittiin, kuinka luotettavasti hammaslääkäreiden käytössä olevin menetelmin pystytään arvioimaan lasten ahtautuneita ilmateitä. Tutkimusaineistossa oli mukana 70 lasta (36 tyttöä, 30 poikaa, ikä 4.2–11.9 vuotta), joilla diagnosoitiin unenaikainen obstruktiivinen hengityshäiriö vuosina 2000–2002. Lapsille tehtiin kliiniset tutkimukset oikojahammaslääkärin ja korva-, nenä- ja kurkkutautien erikoislääkärin toimesta sekä otettiin lateraalikallokuva ja hampaistosta kipsimallijäljennökset. Lisäksi ylempien hengitysteiden magneettitutkimus suoritettiin 36 lapselle eri pään asennoissa. Verrokkiryhmässä oli sama ikä- ja sukupuolijakauma kuin tutkimusryhmässä. Tulokset osoittivat, että unenaikaisista hengityshäiriöistä kärsivillä lapsilla horisontaalinen ylipurenta oli suurentunut, vertikaalinen ylipurenta oli pienentynyt, ylähammaskaari oli kapeampi ja alahammaskaari lyhyempi kuin terveillä verrokeilla. Alaetualueen ahtaus ja etualueen avopurenta olivat yleisempiä niillä lapsilla, joilla oli vaikeampiasteinen hengityshäiriö. Lasten unenaikaiset hengityshäiriöt liittyivät suurentuneeseen leukojen väliseen kokoepäsuhtaan, alaleuan avautuvaan kasvumalliin, pidempään ja paksumpaan pehmeään suulakeen, kieliluun alempaan asentoon, kohonneeseen pään asentoon sekä ahtaampiin nielun ilmatilan mittoihin verrattaessa terveisiin lapsiin. Häiriön vaikeusaste korreloi suurempiin poikkeamiin nielun mitoissa. Lapsilla, joilla todettiin unenaikainen hengityshäiriö, magneettitutkimukset osoittivat nielun olevan ahdas. Pään asennon vaikutukset ilmatien rakenteeseen poikkesivat unenaikaisista hengityshäiriöistä kärsivillä lapsilla. Saadut tulokset osoittivat, että hengitystapa voi vaikuttaa hampaiston, kasvojen ja leukojen rakenteiden kehitykseen. Tietyt kasvojen ja leukojen piirteet puolestaan saattavat altistaa häiriön kehittymiselle. On tärkeää tunnistaa nämä merkit, jotta kehitystä voidaan ohjata suotuisampaan suuntaan. Tutkimukset osoittivat, että kefalometrinen analyysi on luotettava arvioitaessa nenänielun sekä pehmeän suulaen takana olevan ilmatilan kokoa. Nielurisojen kliinisen koon arviointi on luotettava arvioitaessa alemman suunielun ilmatilan kokoa.
186

Alterações pulpares e periapicais decorrentes de sobrecarga oclusal em ratos associadas ou não à periodontite induzida / Pulp and periapical changes due to occlusal overload in rats associated or not induced periodontitis

Luiz Fernando Varrone 16 September 2010 (has links)
As alterações pulpares e periapicais decorrentes de sobrecarga oclusal são problemas que acometem considerável parcela da população. Geralmente causadas por contato prematuro de restaurações com material em excesso, provocam um trauma de baixa intensidade, porém de alta frequência. Objetivo: Avaliar as alterações pulpares e periapicais, induzidas por esta sobrecarga oclusal associada ou não à doença periodontal induzida em dentes de ratas. Método: Foram utilizadas vinte ratas (Wistar) com noventa dias de idade e peso aproximado de 250g divididas em quatro grupos (n=5): GC (controle), GT (trauma), GL (ligadura) e GLT (ligadura e trauma), com sobrecarga oclusal e periodontite induzida restritas aos primeiros molares inferiores, que receberam a ligadura. As superfícies oclusais dos segundos e terceiros molares superiores receberam desgastes, sem que houvesse exposição pulpar e os animais foram observados por um período de quatro semanas. Depois de anestesiados, estes foram decapitados com uma guilhotina e, após a eutanásia, as hemi-mandíbulas foram enviadas para a análise histológica do tecido pulpar e periapical, com coloração por hematoxicilina-eosina, para avaliação da presença de nódulos pulpares, lacunas de reabsorção e células inflamatórias, além de submetidos à análise histoquímica pela Fosfatase Ácida Tartarato Resistente (TRAP) para avaliação da presença de células clásticas e pré-clásticas. Resultados: Histologicamente, os dentes submetidos à ligadura apresentaram presença moderada de fibras e vasos, enquanto os submetidos ao trauma e ao conjunto trauma-ligadura apresentaram grande aumento de vasos e fibras além de infiltrado neutrofílico e, por vezes, nódulos. Histoquimicamente, notou-se certa normalidade no GC, uma irregularidade na região cervical externa no GL e maior presença de lacunas dentinárias e células multinucleadas no GT e GLT. Conclusão: A sobrecarga oclusal provoca alterações pulpares e periapicais assim como a doença periodontal induzida. Mas a associação da doença periodontal e da sobrecarga é mais lesiva aos tecidos pulpares e radiculares. / Pulp and periapical changes resulting from occlusal overload are problems that affect a considerable portion of the population. Generally caused by premature contact of restorations with material in excess, cause a trauma of low intensity, however high frequency. Objective: To evaluate the changes of pulpal and periapical induced by this overload occlusal associated or not to the induced periodontal disease in teeth of rats. Method: Used twenty rats (Wistar) with ninety days old and weighing approximately 250g divided into four groups (n = 5): GC (control), GT (overload), GL (ligature) and GLT (ligature and overload) with occlusal overload and induced periodontitis restricted to lower first molars, which received the ligature. The occlusal surfaces of upper second and third molars were worn away, with no pulp exposure and the animals were observed for a period of four weeks. Once anesthetized, they were beheaded with a guillotine and, after euthanasia, the hemi-mandibles were sent for histological analysis of pulp and periapical with hematoxylin-eosin staining for evaluation of nodules pulp, resorption gaps and inflammatory cells, and analyzed by immunohistochemistry Tartrate Resistant Acid Phosphatase (TRAP) for assessing the presence of clastic cells and pre-clastic. Results: Histologically, the teeth underwent to ligature showed the presence of fibers and vessels, while the other submitted to overload and overload-ligature group showed a large increase in vessels and fibers as well as neutrophil infiltration and sometimes nodules. Histochemically, it was noted some degree of normality in the GC, an irregularity in the external cervical region in the GL and greater presence of dentinal gaps and multinucleated cells in the GT and GLT. Conclusion: The occlusal overload causes changes pulp and periapical as well as induced periodontal disease. But the association between periodontal disease and the overload occusal is more damage to pulp and root tissues.
187

Maximal voluntary occlusal bite force in young adult men -a pilot study

Alkhaiat, Reem, Jaber, Zahra January 2020 (has links)
Background: Maximal voluntary occlusal bite force (MVOBF) is the maximal force applied by the jaw muscles in dental occlusion. MVOBF is one parameter for functional capacity of the jaw system.  Aim: To evaluate MVOBF in different positions in the bite and to evaluate possible intra-individual differences between sessions.  Methods: MVOBF was measured with an electronic bite force device, with transducers sensitive to force, in 20 healthy men (mean 24.5 years). Eligibility of participants was full dental occlusion, Angle Class I relation, no diagnosis according to Diagnostic criteria for temporomandibular disorders. The test included three repeated measurements on each site: first molar right, first molar left and central incisor, in random order, with test-retest study design. Unpaired T-test was used to test the MVOBF in different positions in the bite and paired T-test for possible intra-individual differences between sessions. A post hoc test for repeated measure one-way ANOVA was added.  Results: MVOBF in different positions in the bite was lower in the incisor area compared with the molar region (P<0.0001), but similar between right and left molar side (P=0.48 and P= 0.96, respectively). No intra-individual differences between sessions (molar right P= 0.40; molar left P= 0.81; incisor area P= 0.66). The intra-individual variability for repeated measurements showed variability for incisor area (P= 0.007), but not for molar right and left region (P=0.95 and P=0.49, respectively).  Conclusion: The results may provide reference values for MVOBF in young adult men, to be compared with men with pain or dysfunction in the jaw system.
188

Dimenzije gornjih respiratirnih puteva kod malokluzije klase II/1 / Upper airway dimensions in class II/1 malocclusion

Ivić Stojan 31 October 2014 (has links)
<p>Uvod: Kraniofacijalni sistem je svim svojim strukturama razvojno, funkcionalno i anatomski tesno vezan sa strukturama gornjih respiratornih puteva. Tako je svaki poremećaj u jednom od njih često praćen manjim ili većim poremećajem u drugom. Ovaj rad se bavi utvrđivanjem mogućnosti da se prepoznaju neki od orofacijalnih faktora kod dece koji bi mogli da uzrokuju ili povećaju ozbiljnost smetnji u disanju. Od posebnog je značaja činjenica da se većina autora bavi tretiranjem odrasle populacije, dok samo nastajanje poremećaja nije jasno obja&scaron;njeno. Zbog toga je ovaj rad zami&scaron;ljen kao doprinos saznanju o nekim od mnogih međusobno veoma kompleksno isprepletanih funkcionalnih i morfolo&scaron;kih poremećaja koji svi zajedno dovode do ovog potencijalno opasnog, a globalno prisutnog stanja. U ovom istraživanju posebna pažnja se obraća na uticaj poremećenih međuviličnih odnosa u sagitalnoj dimenziji (posteriorni odnos struktura donje vilice) kod dece koja nisu zavr&scaron;ila rast i kod koje se jo&scaron; uvek može terapijski delovati, kao i na sagitalnu uskost gornjih respiratornih puteva. Skeletno II klasa je poremećaj kraniofacijalnog razvoja koji se u dece leči, dok je kod odraslih sa zavr&scaron;enim rastom taj odnos vilica fiksiran. Ispravljanje morfolo&scaron;ke nepravilnosti kod dece koriguje se pravilnim usmeravanjem rasta, i normalizacijom poremećenih funkcija orofacijalne i nathioidne muskulature, &scaron;to se postiže primenom funkcionalnih ortodontskih aparata. Ciljevi i hipoteze: Op&scaron;ti cilj rada je da se doprinese saznanjima o dimenzijama struktura u periodu razvoja koje mogu u kasnijim životnim dobima da doprinesu nastanku smetnji u disanju i nekom od &scaron;irokog spektra poremećaja opisanih kao sindrom opstruktivnog prekida disanja u toku sna, kao i da se sagledaju mogućnosti ranog delovanja na njih. Metode: Ispitivanje je sprovedeno kao kombinacija studije preseka u svom prvom delu I kohortne studije u svom drugom delu, na Klinici za stomatologiju Vojvodine. Studijom je obuhvaćeno 98 ispitanika eksperimentalne grupe koji su ispunjavali kriterijume za uključivanje u studiju, odgovarajućeg uzrasta i kraniofacijalne morfologije (druga skeletna klasa i hiperdivergentan rast), kao i 70 (dve grupe po 35) ispitanika kontrolne grupe odgovarajućeg uzrasta kao reprezent op&scaron;te populacije. Kod svih ispitanika izvr&scaron;ena su standardna rendgenkefalometrijska merenja i utvrđene dimenzije gornjih respiratornih puteva, kao i struktura koje bi mogle da imaju uticaja na njih, jezika i mekog nepca. Dobijene vrednosti su upoređene statistički. Posle godinu dana ortodontskog lečenja malokluzije druge klase, pristupilo se ponovnom merenju istih struktura, upoređivanju sa kontrolnom grupom odgovarajućeg uzrasta, kao i utvrđivanju nastalih promena u odnosu na početni nalaz. Da bi se utvrdio stvarni opseg promena nastalih usled ortodontske terapije, upoređen je stepen promene i kod kontrolne grupe na početku i kraju opservacionog perioda. Rezultati: Utvrđene su sagitalne dimenzije gornjih respiratornih puteva kod ispitanika sa hiperdivergentnom malokluzijom klase II/1. Utvrđene dimenzije su značajno manje kod ispitanika sa klasom II/1 nego kod op&scaron;te populacije, na sva tri posmatrana nivoa, nivou nazofarinksa, nivou orofarinksa i nivou hipofarinksa. Ne postoji statistički značajna međuzavisnost između sagitalnih dimenzija gornjih respiratornih puteva i skeletnih odnosa u sagitalnoj dimenziji. Nakon ortodontskog lečenja funkcionalnim aparatima, kod ispitanika su se dimenzije gornjih disajnih puteva na sva tri posmatrana nivoa povećale. Zaključak: Nalazi potvrđuju da su gornji disajni putevi kod osoba sa hiperdivergentnom klasom II/1 uži nego kod ostatka populacije, kao i da uravnotežavanje njihovih morfofunkcionalnih odlika u toku rasta ortodontskim lečenjem dovodi i do skladnijeg razvoja faringealnih struktura koje izgrađuju gornje disajne puteve.</p> / <p>Introduction: Craniofacial system has all of its structures developmentally, functionally and anatomically closely related to the structures of the upper respiratory tract. Thus, any disturbance<br />in any of them is often accompanied by a disorder in the other. This paper is identifying opportunities to recognize some of the orofacial factors in children that could cause or increase the severity of breathing difficulties. Of particular importance is the fact that most authors deal with treating the adult population, while the mere emergence of the developmental disorder is not clearly explained. Therefore, this paper is conceived as a contribution to the knowledge of some of the many mutually very complex, interwoven functional and morphological disorders that together lead to this potentially dangerous, a globally present situation. In this study, special<br />attention is paid to the influence of irregular intermaxillary relationship in the sagittal dimension (posterior position of lower jaw) in children who have not yet completed growth and in which there still can be a therapeutic act, as well as the sagittal narrowness of the upper respiratory tract. Correcting morphological irregularities in children is acheived by modifying and directing the growth and normalization of disturbed functions of orofacial musculature, by the application of functional orthodontic appliances. Objectives and hypotheses: The overall objective of this paper is to contribute to the knowledge of the structures and dimensions of the structures during the period of development, which may in later stages of life contribute to the occurrence of disturbances in breathing and a wide spectrum of disorders described as obstructive sleep apnoea syndrome, as well as to examine the possibility of affecting them early. Methods: The study was conducted as a combination of cross-sectional study in the first part and cohort study in its second part. It was performed at the Clinic of Dentistry of Vojvodina. The study included 98 experimental group subjects who met the criteria for inclusion in the study, appropriate age and craniofacial morphology (second class and hyperdivergent skeletal growth), and 70 (two groups of 35) of controls, being of corresponding ages. Roentgenocephalometric features and the dimensions of the upper respiratory tract were assessed in all subjects, as well as structures that could influence them, tongue and soft palate. The values obtained were compared statistically. After a year of orthodontic treatment of class II malocclusion, re- measurement of the same structures was performed, as well as the comparison with a control group of corresponding age. Changes in relation to the initial findings were tracked. To determine the actual extent of the changes caused by orthodontic treatment, the degree of change was compared in the control group at the beginning and end of the observation period. Results: The sagittal dimensions of the upper respiratory tract are significantly smaller in patients with Class II/1 than in the general population in all three observed levels, the level of the nasopharynx, oropharynx, and the level of level of hypopharynx. There was no significant interdependence between the sagittal dimension of the upper respiratory tract and skeletal relationships in the sagittal dimension. After orthodontic treatment by the means of functional appliances, the dimensions of the upper airway in all three observed levels increased. Conclusion: The findings confirm that the upper airway in patients with hyperdivergent class II/1 malocclusion is narrower than in the rest of the population, as well as that balancing their morphofunctional facial features during growth by orthodontic treatment leads to the more harmonious development of the pharyngeal structures that make up the upper airways.</p>
189

Enhanced Computerized Surgical Planning System in Craniomaxillofacial Surgery

Chang, Yu-Bing 2011 May 1900 (has links)
In the field of craniomaxillofacial (CMF) surgery, surgical planning is an important and necessary procedure due to the complex nature of the craniofacial skeleton. Computed tomography (CT) has brought about a revolution in virtual diagnosis, surgical planning and simulation, and evaluation of treatment outcomes. It provides high-quality 3D image and model of skull for Computer-aided surgical planning system (CSPS). During the planning process, one of the essential steps is to reestablish the dental occlusion. In the first project, a new approach is presented to automatically and efficiently reestablish dental occlusion. It includes two steps. The first step is to initially position the models based on dental curves and a point matching technique. The second step is to reposition the models to the final desired occlusion based on iterative surface-based minimum distance mapping with collision constraints. With linearization of rotation matrix, the alignment is modeled by solving quadratic programming. The simulation was completed on 12 sets of digital dental models. Two sets of dental models were partially edentulous, and another two sets have first premolar extractions for orthodontic treatment. Two validation methods were applied to the articulated models. The results show that using the proposed method, the dental models can be successfully articulated with a small degree of deviations from the occlusion achieved with the gold-standard method. Low contrast resolution in CBCT image has become its major limitation in building skull model. Intensive hand-segmentation is required to reconstruct the skull model. Thin bone images are particularly affected by this limitation. In the second project, a novel segmentation approach is presented based on wavelet active shape model (WASM) for a particular interest in the outer surface of the anterior wall of maxilla. 19 CBCT datasets are used to conduct two experiments. This model-based segmentation approach is validated and compared with three different segmentation approaches. The results show that the performance of this model-based segmentation approach is better than those of the other approaches. It can achieve 0.25 +/- 0.2mm of surface error distance from the ground truth of the bone surface. Field of view (FOV) can be reduced in order to reduce unnecessary radiation dose in CBCT. This ROI imaging is common in most of the dentomaxillofacial imaging and orthodontic practices. However, a truncation effect is created due to the truncation of projection images and becomes one of the limitation in CBCT. In the third project, a method for small region of interest (ROI) imaging and reconstruction of the image of ROI in CBCT and two experiments for measurement of dosage are presented. The first experiment shows at least 60% and 70% of radiation dose can be reduced. It also demonstrates that the image quality was still acceptable with little variation of gray by using the traditional truncation correction approach for ROI imaging. The second experiment demonstrates that the images reconstructed by CBCT reconstruction algorithms without truncation correction can be degraded to unacceptable image quality.
190

Relação da otite média secretora com o crescimento craniofacial e as características oclusais / The relationship of otitis media with effusion to the craniofacial growth and occlusal features

Nery, Claudio de Gois 13 August 2008 (has links)
O objetivo deste estudo foi avaliar a morfologia/crescimento craniofacial e a oclusão dentária em pacientes (ambos sexos), entre 4 e 10 anos e aumento adenoamigdaliano com e sem otite média secretora (OMS). Utilizou-se análise cefalométrica e modelos de estudo dentários. Não foram observadas diferenças significativas entre os grupos estudados, em relação às medidas lineares e angulares adotadas, exceto, a medida correspondente ao comprimento do palato ósseo (ENA-ENP), que mostrou relação com a idade e a OMS. Não houve um tipo facial predominante. Observou-se discreta predominância de mordida profunda, mordida cruzada posterior e desvio da linha média em relação à OMS, porém sem significância estatística. A atresia maxilar pode estar associada à OMS, assim como sua redução pode estar relacionada ao crescimento e desenvolvimento craniofacial / The aim of this study was to evaluate the craniofacial growth/morphology and dental occlusion in 100 patients (male and female) from 4 to 10 years old and tonsils and adenoid enlargement. There were two groups: with and without otitis media with effusion (OME). We used the cephalometric analyses and dental casts. It was not observed significant differences between the two groups, in relationship to the linear and angular measurements adopted, except for the measurement corresponding to the palate bone length, which had shown correlation with age and OME. It was not found a facial pattern predominance. It was observed a discreet predominance of deep bite, posterior cross bite and midline deviation to OME, however without statistical significance. The maxillary narrowing might be associated to OME as well as its reduction may be related to the craniofacial growth and development

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