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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.
151

Electromyography and bite force studies of muscular function and dysfunction in masticatory muscles

Hagberg, Catharina January 1986 (has links)
Electromyographic (EMG) activity versus bite force was studied during a gradually increased isometric contraction up to maximal effort for patients with painful masseter muscles and referents. The masseter muscle, the anterior temporal muscle and the descending part of the trapezius muscle were chosen for the recordings. Bite force was registered with a bite force sensor placed between the first molars. The effects of double blind intramuscular injections of lidocaine and saline in the patients' masseter muscle were evaluated by EMG versus bite force and by assessments of discomfort. EMG activity during unilateral chewing was compared in terms of relative masticatory force between referents and patients by amplitude probability distribution analysis. Regression analyses showed intra-individually steeper slopes for high force levels than for low force levels for the masseter muscle. This was not observed for the anterior temporal muscle. These differences in slopes of the EMG versus force regressions for the masseter muscle and the anterior temporal muscle could be due to differences in recruitment pattern. The same intra-individual relationship between low and high force levels was found for referents and patients. An increased activity, especially among the patients, was found for the descending part of the trapezius muscle during stronger activity of the mandibular elevators. The EMG versus force relationship for low force levels of the masseter muscle was less steep after an intramuscular injection of lidocaine but not after saline. Both solutions for injection had a positive effect on the patients' assessments of discomfort one week after the injection. Three days after injection the patients who received lidocaine experienced a reduction in muscular discomfort. This reduction was not found among patients receiving saline. The amplitude probability distribution analysis revealed that the patients used greater relative masticatory forces than the referents during the chewing of an almond for all probability levels analysed below the peak load of the masseter muscles. Rough estimates of the peak masticatory forces in Newton (N) were for chewing an almond 364 N (referents); 373 N (patients) and for gum-chewing 239 N (referents); 238 N (patients) as regards the masseter muscle. The values were similar for the anterior temporal muscle. / digitalisering@umu
152

Avaliação morfofuncional dos músculos mastigatórios e cervicais em adultos com e sem disfunção temporomandibular / Morphofunctional evaluation of the masticatory and cervical muscles in adults with and without temporomandibular disorders

Strini, Paulinne Junqueira Silva Andresen, 1981- 07 April 2011 (has links)
Orientador: Maria Beatriz Duarte Gavião / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-18T16:08:10Z (GMT). No. of bitstreams: 1 Strini_PaulinneJunqueiraSilvaAndresen_D.pdf: 1270015 bytes, checksum: ce570be92994879d1100cbb088608e3e (MD5) Previous issue date: 2011 / Resumo: As desordens temporomandibulares (DTM) consistem em um grupo de alterações que afetam o sistema estomatognático, especialmente o componente muscular. O objetivo deste trabalho foi avaliar a força máxima de mordida (FMM), a atividade eletromiográfica (EMG) e a espessura dos músculos mastigatórios e cervicais por meio da ultrassonografia (US), além da influência clínica da postura de cabeça, em adultos com e sem a presença de DTM. A amostra foi composta por 47 indivíduos, de ambos os gêneros, sendo 19 incluídos no grupo DTM (idade de 25,4±3,8 anos), classificados de acordo com o Research Diagnostic Criteria (RDC/TMD) e 28 incluídos no grupo controle (idade de 25,9±4,7 anos). Uma linha de prumo foi usada como referência para verificar o alinhamento e identificar clinicamente o lado de inclinação da cabeça. A FMM foi determinada por um transdutor de pressão posicionado entre os arcos dentais até o nível dos primeiros molares e os valores foram convertidos em Newtons. A EMG e a US foram avaliadas para os músculos masseter, temporal e esternocleidomastóideo (ECM), no repouso e em contração voluntária máxima (CVM), bilateralmente. A normalidade dos dados foi verificada pelo teste de Shapiro-Wilks e a comparação entre os dados realizada por testes paramétricos e não paramétricos, sendo a correlação obtida pela Correlação de Spearman (p?0.05). Os resultados demonstraram diferenças estatisticamente significantes quando comparados os valores de FMM entre o grupo DTM (285,5±98,8 N) e controle (353,4±69,6 N). Diferenças significativas também foram observadas para a espessura do músculo masseter, entre o grupo DTM (11,2±1,9 mm, repouso; 13,4±1,9 mm, CVM) e o controle (12,7±1,8 mm, repouso; 14,8±2,0 mm, CVM) e entre o estado de repouso e contração, em ambos os grupos, para os músculos mastigatórios. Em relação ao gênero, a FMM foi menor nos indivíduos do sexo feminino com DTM, bem como a espessura dos músculos analisados, em ambos os grupos. Os valores de EMG para o ECM demonstraram diferenças significativas entre o estado de repous o (100,6±28,0%) e de CVM (105,6±101,9%) para o grupo controle, com maiores escores durante o apertamento dentário. Da mesma forma, diferenças significativas foram observadas entre o grupo controle e DTM para a EMG do ECM, durante a flexão de cabeça, para o ECM do lado direito (77,0 ±34,2%, DTM; 115,6 ±56,8%, controle) e esquerdo (80,7±46,1%, DTM; 113,1±49,5%, controle), e na espessura do ECM na extensão, para o lado esquerdo (10,0±2,0 mm, DTM; 10,9 ±1,5 mm, controle) e no repouso para o lado direito (10,4±1,8 mm, DTM; 11,5±1,8 mm, controle). Adicionalmente, correlações significativas foram encontradas entre os valores de FMM, US e EMG do masseter, temporal e ECM para o grupo DTM e também quando considerado o lado de inclinação de cabeça para o ECM. Pode-se concluir que pacientes com DTM apresentaram menores valores de FMM e alterações na função muscular capazes de afetar os músculos mastigatórios e cervicais, especialmente durante os movimentos mandibulares, revelando a existência de uma ligação funcional entre eles / Abstract: Temporomandibular disorders (TMD) are a group of changes that affect the stomatognathic system, especially the muscular component. The aim of this study was to evaluate the maximum bite force (MBF), the electromyographic activity (EMG) and the thickness of masticatory and neck muscles by means of ultrasonography (US), in addition to clinical influence of head posture, in adults with and without TMD. The sample consisted of 47 individuals of both genders, with 28 included in the control group (mean age 25.9±4.7 years old) and 19 in the TMD group (25.4±3.8 years old), classified according the Research Diagnostic Criteria (RDC / TMD). A plumb line was used as reference to verify the alignment and to define the side of head tilt. MBF was determined by a pressure transducer positioned between the dental arches to the level of first molars and the values were converted into Newtons. EMG and US were evaluated for the masseter, temporalis and sternocleidomastoid (SCM) at rest and at maximal voluntary contraction (MVC), bilaterally. Data normality was checked by Shapiro-Wilks and the comparison between the data done by parametric and nonparametric tests, with the correlation obtained by Spearman's correlation (p ? 0.05). The results showed statistically significant differences when comparing values of MBF between TMD (285.5 ±98.8 N) and controls (353.4 ±69.6 N). Significant differences were also observed for thickness of the masseter muscle between the TMD (11.2±1.9 mm, rest; 13.4±1.9 mm, MVC) and the control group (12.7±1.8 mm, rest; 14.8±2.0 mm, MVC) and between the state of rest and contraction in both groups for the masticatory muscles. In relation to gender, MBF was lower in female subjects with TMD as well the thickness of the muscles analyzed, in both groups. The values of EMG for the SCM showed significant differences between the resting state (100.6 ±28.0 %) and MVC (105.6 ±101.9 %) in the control group, with greater scores during dental clenching. In the same way, significant differences were observed between the control and TMD for SCM activity during head flexion for right (77.0±34.2 %, TMD; 115.6 ±56.8 %, control) and left SCM (80.7 ±46.1 %, DTM; 113.1±49.5 %, control) and for the thickness of the SCM during extension, to the left side (10.0±2.0 %, TMD; 10.9±1.5 %, control) and at rest to the right side (10.4±1.8 %, TMD; 11.5±1.8 %, control). Additionally, a significant correlation was found between values of the MBF, US and EMG of the masseter, temporal and SCM for TMD group and also when considered the side of head tilt for SCM. Thus, it can be concluded that patients with TMD showed smaller values of MBF and changes in muscle function that may affect the masticatory and neck muscles, especially during the mandibular movements, revealing the existence of a functional link between them / Doutorado / Anatomia / Doutor em Biologia Buco-Dental
153

Comparação da força de mordida pré e pós tratamento endodôntico em molares inferiores com periodontite apical assintomática / Comparison of bite force pre and post endodontic treatment in lower molar with asymptomatic periodontitis

Anacleto, Felipe Nogueira, 1983- 03 October 2015 (has links)
Orientador: Caio Cezar Randi Ferraz / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T21:48:03Z (GMT). No. of bitstreams: 1 Anacleto_FelipeNogueira_M.pdf: 1773545 bytes, checksum: c2db927cede9fb1831811991d3b70d9b (MD5) Previous issue date: 2015 / Resumo: Tão importante quanto a avaliação pulpar, o diagnóstico periapical dos dentes com necessidade de tratamento endodôntico, é realizado por testes com resultados imprecisos, inquantificáveis e de difícil validação. Portanto, o objetivo deste trabalho foi comparar a força de mordida (FM) pré e pós-operatória em molares inferiores com periodontite apical assintomática. Foram avaliados 31 pacientes (20 mulheres e 11 homens), o dente incluído foi mensurado quanto a força de mordida (FM) registrada em Newton(N) com o medidor de força oclusal Occlusal Force-Meter GM10 e também seu representante contralateral. O tratamento foi realizado em duas sessões, na primeira o dente foi acessado, descontaminado por técnica crown down, a odontometria realizada por um localizador apical Root ZX II (J. Morita, Japão). O comprimento de trabalho adotado foi 1mm aquém do forame apical com patência e a substância química auxiliar foi o hipoclorito de sódio 6%, o preparo mecânico foi realizado com sistema rotatório Protaper® Universal (Dentsply, EUA) e os dentes foram medicados com hidróxido de cálcio e soro fisiológico por 07 dias. Na segunda sessão o dente foi novamente acessado, a medicação removida, o dente obturado com guta percha e restaurado definitivamente com resina composta. As avaliações de força de mordida pós operatória foram feitas com 48 horas e 7 dias pós obturação. Os valores foram comparados por análise estatística ANOVA e teste t Tuckey (?= 0.05) com os resultados dos dentes contralaterais. Os resultados apresentaram diferença estatística do grupo teste com o grupo contralateral na avaliação inicial da FM e na avaliação da FM 48 horas pós obturação. Conclui-se que os dentes tratados tiveram nas primeiras 48 horas redução da força de mordida, porém com 7 dias de finalização do tratamento os valores da FM se restabelecem comparados com os dentes contralaterais / Abstract: As important as the pulp evaluation, the diagnosis of periapical teeth recquiring endodontic treatment is done by testing with inaccurate results, unquantifiable and difficult validation. Therefore, the aim of this study was to compare pre and postoperative bite force (BF) in mandibular molars with asymptomatic apical periodontitis. 31 patients were evaluated (20 females and 11 males), the included tooth as well as its contralateral representative bite force (BF) were measured and recorded in Newton (N) using an occlusal force meter (Occlusal Force-Meter GM10). The treatment was performed in two sessions, in the first one, the tooth was accessed, decontaminated by crown down tecnique, odontometry performed by an apex locator Root ZX II (J. Morita, Japan). The adopted working length was 1 mm short of the apical foramen with patency and the auxiliary chemical substance was 6% sodium hypochlorite, the mechanical preparation was performed using Protaper® Universal rotary system (Dentsply, USA) and the teeth were filled with calcium hydroxide and saline by 07 days. In the second session the tooth was again accessed, medication removed, the tooth filled with gutta percha and definitely restored with composite resin The postoperative bite force evaluations were made 48 hours and 7 days post obturation. The values were compared by ANOVA and Tukey Student's t test (? = 0.05), with the contralateral teeth results. The results showed statistical difference of the test group compared to the contralateral group at baseline BF and at BF 48 hours after obturation evaluations. It is concluded that the treated teeth had an operative sensitivity within 48 hours with reduced bite force, but in 7 days of completion of the treatment the BF values were restored compared to the contralateral teeth / Mestrado / Endodontia / Mestre em Clínica Odontológica
154

Articulatory Kinematic Differences During Adaptation to a Bite Block

McHaley, Madison Ann 01 June 2018 (has links)
The current study examined the effects of bite blocks on articulatory kinematics when producing /r/ within a phrase. Participants consisted of 20 young adults (10 males, 10 females) with no speech, language or hearing disorders. Participants produced the carrier phrase, I say __ with the nonsense words /əri/ (high front vowel), /əræ/ (low front vowel), /əru/ (high back vowel), /ərɑ/ (low back vowel). A Northern Digital Instruments Wave electromagnetic articulograph measured the articulatory movements while the speaker produced the stimuli in two conditions (Pre bite block and post bite block). Bilateral bite blocks were made using Express dental putty, which is a silicone impression material, in order to create an inter-incisal gap of 10 mm. The hull area (i.e., a boundary enclosing the total distance the sensor traveled during the target phrase) of the data for each sensor (i.e., tongue back, tongue mid, tongue front, lower lip, mandibular central incisor) was calculated for the individual nonsense words /eɪərɑ/, /eɪəræ/, /eɪəri/, and /eɪəru/. Results revealed kinematic differences across vowel phrases and between genders. The hull area of the tongue and jaw were significantly different for the vowel phrases /eɪəræ/, /eɪəri/, and /eɪəru/ compared to /eɪərɑ/. The hull area for the jaw for /eɪərɑ/ was significantly larger than the other vowel phrases. The between-gender analyses showed larger hull areas for males than females. Different motor equivalent strategies for tongue movements were observed when speakers produced /eɪərɑ/ and there were individual differences in compensating for the presence of the bite block
155

Monitorování technického stavu částí radarových systémů / Technical Condition Monitoring of Radar Systems Components

Miklíček, Marek January 2017 (has links)
The goal of this thesis is to design a diagnostic subsystem for secondary surveillance radar and to construct a functional prototype of communication and testing generator unit. The first part of the thesis aims at description and division of radar systems, with emphasis on air traffic control radars.  Main attention is being focused on ATC secondary surveillance radars and description of their function. Following part deals with requirements specification for design of diagnostic system and the system design itself. Part of the thesis forms design, production and testing of prototype of block enabling communication of diagnostic subsystem and function of testing generator for secondary surveillance radar.
156

Quantifying the link between craniodental morphology and diet in Soricidae using geometric morphometrics

Tse, Yuen Ting January 2020 (has links)
No description available.
157

Pet awareness with students (P.A.W.S.): the development of age appropriate materials for teaching public health education to children

Ray, Joel Dillard 30 April 2011 (has links)
The purpose of this study was to determine if the animal bite prevention and zoonotic disease program in Pet Awareness With Students (P.A.W.S.) is an effective educational program for younger elementary children. An educational program was delivered and student learning was determined through a pretest and post-test. This program utilized the Classroom Performance System (CPS) to collect responses from first grade students. Responses were collected and compared to the second grade participants who used paper methodology. It was determined that these age groups had little knowledge of animal bites and zoonotic disease. Gender was not related to either pretest or post-test scores. The effect of bite history or having pets at home was also examined. It was determined via test scores that first and second graders have the capacity to learn the information provided. Stakeholder evaluation was positive and provided further impetus for future studies.
158

Performance and Signaling in the Green Anole Lizard

Henningsen, Justin P. 01 September 2013 (has links)
Green anoles are small lizards of the Southeastern United States. They possess an extensible throat-fan called a dewlap. Males have larger dewlaps and display them more often than females. Displays occur during courtship, during agonistic interaction, and during encounters with potential predators. The size of the dewlap of male green anoles is positively correlated with maximum bite force capacity. Bite force capacity, in turn, is predictive of the winner during agonistic interactions. The correlation between these traits suggests that dewlap size may be used as a reliable signal of maximum bite force capacity. In this dissertation, I address three components of this system. First, I manipulate dewlap size and stage interactions between male green anoles. By removing the correlation between dewlap size and bite force, I was able to show that during staged encounters, bite force is predictive of the winner, but dewlap size is not. In the second chapter, I test for potential costs due to an increased predation risk as a result of dewlap displays. I observed no difference in recapture rates between animals that were experimentally prevented from extending their dewlaps and control counterparts. However, other data suggest that the presence of a pink dewlap may increase risk of predation. These results suggest that though there may be a predation-based cost to dewlap displays, green anoles use behavioral means to ameliorate this risk. Finally, I use a castration and hormone-replacement experiment to test whether testosterone mediates seasonal changes in dewlap size and bite force. I hypothesized that testosterone would mediate changes in both traits in order to maintain the correlation between them. However, I found no effect of testosterone on change in dewlap size or bite force performance. Another trait, sprint speed performance, was affected by hormone treatment in the breeding season such that animals with high levels of testosterone ran faster than animals from the other treatment groups. My results corroborate other research showing that hormones regulate plasticity in some systems, while other systems are insensitive. However, the mechanisms that regulate changes in the two components of the reliable signaling system in green anoles remain unknown.
159

Articulatory Kinematic Compensation for a Bite Block During Diphthong Production

Richins, Michelle Olson 01 April 2019 (has links)
The current study examined the effects of bite blocks on articulatory kinematics when producing diphthongs /ɑɪ/ and /ɑʊ/ within a phrase. Participants consisted of 20 young adults (10 males, 10 females) with no speech, language or hearing disorders. Participants produced the diphthongs in the carrier phrase Im an owl that hoots. A Northern Digital Instruments Wave electromagnetic articulograph measured the articulatory movements while the speaker produced the stimuli in two conditions (pre bite block insertion and post bite block insertion). Bilateral bite blocks were made using Express dental putty, which is a silicone impression material, in order to create a 10 mm inter-incisal gap. Marker distance, maximum speed, and jaw contribution to tongue movement for three sensors (tongue back, tongue mid, tongue front) were calculated for the diphthongs segmented from the carrier phrase. F1 and F2 transitions and rate were also calculated for each diphthong. Results revealed kinematic differences during diphthong production after the bite block was inserted. Tongue movements independent from the jaw increased after the bite block was inserted, especially during production of the diphthong /ɑʊ/. Bite block by gender interactions during production of the diphthong /ɑɪ/ revealed larger and faster initial movements for males. The results did not reveal any significant acoustic changes other than a longer transition duration. Kinematic adjustments were sufficient to maintain overall similar acoustic output before and after bite block insertion.
160

Kinematic and Acoustic Vowel Changes in Adult Bite Block Speech

Low, Tanner Keith 01 June 2019 (has links)
The current study examined the lingual kinematic and acoustic effects of bite blocks on vowels in a sentence context. Twenty adult native English speakers (10 male, 10 female) with no speech, language, or hearing deficits participated in the study. The corner vowels found in the sentence, The blue spot is on the black key again (i.e., /u/, /ɑ/, /æ/, /i/), were measured kinematically and acoustically immediately before and after bite block insertion. The participants' speech was audio-recorded and their lingual articulatory movements were measured with a Northern Digital Instruments Wave electromagnetic articulograph. The sensor coils were attached to three different parts on the tongue (back, middle, and front). Acoustic analysis of the vowel formants revealed that the vowel articulation index and vowel space area decreased significantly following bite block insertion. Kinematic analysis of the sensors on the tongue revealed that the kinematic vowel articulation index decreased significantly for the back and middle of the tongue but not for the front. Thus, adjustments to the position of the front of the tongue were sufficient to compensate for the bite block perturbation, while the same measures for the back and middle of the tongue were significantly affected. This was likely due to the relative independence in the movement of the front of the tongue, given its distance from the posterior point of attachment between the tongue and mandible. These findings suggest that the effects of articulatory perturbation can be more fully understood when kinematic and acoustic measures are considered together.

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