O sistema estomatognático identifica um conjunto de estruturas bucais que desenvolvem funções comuns, tendo como característica constante a participação da mandíbula. Como todo sistema, tem características que lhe são próprias, mas depende do funcionamento, ou está intimamente ligado à função de outros sistemas como o nervoso, o circulatório e o endócrino. Tanto nos estados de saúde como nos de enfermidade, o sistema estomatognático pode influir sobre o funcionamento de outros sistemas como o digestório, respiratório e o metabólico-endócrino. Várias são as doenças e eventos clínicos que podem acometer o sistema estomatognático, acarretando o seu desequilíbrio ou mau funcionamento. Este estudo teve como objetivo analisar a espessura muscular e a força de mordida em 20 indivíduos diagnosticados com toro mandibular (Grupo Casos) e em 20 indivíduos sem toro (Grupo Controles). Para a análise ultrassonográfica foi utilizado o ultrassom portátil da marca NanoMaxx, com um transdutor linear - L 25 - de 06 a 13 MHz e 23 mm. Foram adquiridas três imagens ultrassonográficas dos músculos masseter e temporal, de ambos os lados, na posição de repouso e de contração voluntária máxima. Os registros da força de mordida foram realizados utilizando o dinamômetro digital, modelo IDDK (Kratos). As avaliações foram feitas nas regiões do primeiro molar (direito e esquerdo). Verificou-se que, os indivíduos portadores de toro na mandíbula apresentaram espessura dos músculos temporais significantemente menores que a dos indivíduos do Grupo Controles, enquanto que, os resultados para a força de mordida máxima foram significativamente maiores para os indivíduos do Grupo Casos e que não ocorreram correlações entre as espessuras e a força de mordida. Concluiu-se que a presença de toro mandibular promoveu alterações no sistema estomatognático. / The stomatognathic system has a set of oral structures that develop common functions, having as a constant share of the jaw. Like any system, it has characteristics of its own, but depends on the functioning, or is closely linked to the function of other systems such as the nervous, circulatory and endocrine. Both the states of health and illness in the stomatognathic system can influence the operation of other systems such as the digestive, respiratory and metabolic - endocrine. There are many diseases and clinical events that may affect the stomatognathic system, causing your imbalance or dysfunction. This study aimed to analyze the muscle thickness and bite force in 20 individuals diagnosed with mandibular torus (Cases Group) and 20 individuals without torus (Controls Group). For the analysis we used the ultrasound portable NanoMaxx, with a linear transducer - L 25 - 06-13 MHz and 23 mm. Three ultrasound images were acquired from masseter and temporalis muscles on both sides, at rest and maximal voluntary contraction. The records of bite force were performed using the digital dynamometer, IDDK model (Kratos). The assessments were made in the regions of the first molar (right and left). It was found that individuals with mandibular torus showed temporalis muscles thickness significantly lower than Controls Group subjects, whereas the results for the maximum bite force were significantly higher for Cases Group subjects, and there were no correlations between the thicknesses and the bite force. It was concluded that the presence of mandibular torus promoted changes in the stomatognathic system.

Orientador: Eduardo Piza Pellizzer / Resumo: A associação entre as próteses parciais removíveis e os implantes osseointegrados é, ainda, uma opção de tratamento muito pouco explorada na Odontologia reabilitadora moderna. Por isso, o objetivo deste estudo é avaliar, utilizando o método dos elementos finitos bidimensional, a distribuição de tensão nas estruturas de suporte da prótese parcial removível de extremidade livre (PPREL) associada a um implante osseointegrado de 10,0 x 3,75 mm (Sistema Branemark), localizado na região posterior do rebordo alveolar desdentado, atuando como suporte para a base da prótese. Para tanto, foram criados três modelos, os quais, em corte sagital, representam: modelo A (MA) - hemiarco contendo o dente natural 33 somente e o A rebordo desdentado distal; modelo B (MB) - semelhante ao MA, com uma PPREL convencional substituindo os dentes ausentes; modelo C (MC) - semelhante ao anterior, com um implante na região posterior do rebordo, sob a base da prótese. Com o auxílio do programa de elementos finitos ANSYS 5.4, os modelos foram carregados com forças verticais e oblíquas de 45º, tanto no sentido de mesial para distal como no sentido inverso, de magnitude de 50 N, em cada ponta de cúspide. A análise dos mapas de tensões permitiu concluir que: 1) a tendência de deslocamento no modelo com a PPR apoiada sobre implante é menor que no modelo com a prótese somente; 2) as forças oblíquas de 45º promovem uma tendência de deslocamento e valores de tensão maiores que a força vertical; 3) a força oblíqua de 45º, no sentido de mesial para distal, gera valores de tensão menores que a de distal para mesial e 4) a presença do implante osseointegrado, sob a base da prótese, promove alívio do dente suporte. / Abstract: The association among the removable partial dentures and the osseointegrated implants is still a non very explored option of treatment in the modern prosthetic dentistry. Because of this, the objective of this study is to evaluate, using the two-dimensional finite element analysis, the tension distribution in the support structures of the distal extension removable partial denture (RPD) associated with a 10.0 x 3.75 mm osseointegrated implant (Branemark System), located in the posterior area of the toothless alveolar edge, acting as support for the prosthesis base. Then, three plane strain models were created, represented in sagital cut: Model A (MA) - hemiarc containing the natural tooth 33 and the toothless alveolar edge; Model B (MB) - similar to MA, with a conventional RPD substituting the absent teeth; Model C (MC) - similar to the previous, with an implant in the posterior area of the edge, under the denture base. With the aid of the finite element program ANSYS 5.4, the models were loaded with vertical and 45º inclined forces, in both mesial and distal sides, with 50 N, on each peak point. The analysis of the tensions map allowed to conclude that: 1) the displacement tendency in the model with the RPD supported by the implant is smaller than the model with prosthesis only; 2) the oblique forces of 45º promote a displacement tendency and larger tension values than the vertical force; 3) the mesial to distal 45º oblique force generates smaller tension values than the one of distal to mesial and 4) the presence of the osseointegrated implant, under the denture base, promotes relief to the support tooth. / Mestre

Objectives: Previous studies in the Oral Neurophysiology Laboratories in Dundee have defined the electromyographic properties of the inhibitory jaw reflex that can be evoked in human subjects by electrical stimulation of the lip. This reflex, in contrast with the more widely studied biphasic inhibitory reflexes evoked by stimulation of intra-oral nerves, consists of just a single phase of inhibition and usually requires the application of stimuli which excite nociceptive nerves. The aims of the present studies were to define the mechanical manifestations of this reflex in the form of changes in biting forces, and to investigate whether the mechanical manifestation of the inhibitory jaw reflex evoked by stimulation of the human upper lip, can be modulated by experimentally-controlled conditions that mimic symptoms of a myogenous temporomandibular disorder. Methods: Three series of experiments were performed on 49 volunteer subjects in total. The experiments involved recording bite forces between the anterior teeth and electromyograms (EMGs) from the masseter muscles. Transcutaneous electrical stimuli were applied to the hairy skin of upper lip while the subjects maintained a biting force of around 50N with the aid of visual feedback. In the first series of experiments, a range of electrical stimuli below and above the nociceptive threshold was delivered. In the second set of experiments, double stimuli with a range of different inter-stimulus intervals were applied. Finally in a third series of experiments, electrical stimulation was repeated before, immediately after, and 5 and 10 minutes following a 3-minute accelerated chewing task. This task consisted of chewing 1.5g of a tough chewing gum at 1.5 times the subject’s natural chewing rate and in 18 cases, muscle fatigue and/or pain were reported by the subjects. Results: Following stimulation at intensities that were described as sharp or painful, all the subjects showed both a suppression of the masseter EMG and a reduction of biting force. When analysing the maximum responses in each subject, the mean reduction in the EMG inhibition was to 15.78 ± 14.4% and 10.39 ± 7.92% of the baseline (for the ipsi- and contra-lateral EMGs respectively), whereas the biting force was reduced only to 83.98 ± 11.04% of baseline (+ S.D.). The latencies of onset of these responses were: 38.17 ± 3.58ms, 38.97 ± 4.49ms and 51.83 ± 6.23ms respectively. The response observed in the force record was weaker than in that observed in either EMG (Paired t tests, P < 0.005 in both cases). When applying double stimuli, it was found that the prolongation of the EMG inhibitory jaw reflex (to 144.70 ± 46.93% of the control level) evoked by double stimulation of the upper lip (with a 10 ms inter-stimulus interval) resulted in a greater increase in the depth of the accompanied relaxation (to 223.63 ± 70.88% of that seen in the control responses) compared to a relatively smaller increase in the duration of the relaxation (to 128.32 ± 27.23% of that seen in the control responses). Following the accelerated chewing task, 17 out of 22 subjects reported pain and/or fatigue in one or both of the masseter muscles. The integral for the bite force relaxation significantly decreased in size immediately following the conditioning procedure (to 76.04 ± 35.63% of the control level, P = 0.014; single sample t-test with Bonferroni correction, test value 100). Conclusion: The inhibitory jaw reflex evoked by stimulation of the human lip can be demonstrated mechanically as well as electromyographically although the mechanical version of the response appears less marked. In addition to that, the onset of reflex relaxation in bite force lags several milliseconds behind the corresponding reductions in electromyographic activity. The depth of force relaxation can be increased by increasing the duration of EMG recorded inhibitory reflex. Finally, the results from a chewing task suggest that induced acute pain and/or fatigue cause clear changes in the mechanical manifestation of this inhibitory jaw reflex.

O diagnóstico das desordens temporomandibulares toma como base as informações colhidas sobre a sintomatologia durante a anamnese, o exame clínico da oclusão e os exames radiológicos das articulações temporomandibulares. Na busca de melhor compreensão da fisiopatologia que afeta a musculatura do sistema estomatognático, a análise eletromiográfica tem sido incluída em muitos estudos, pois permite a identificação de quando e como um músculo é ativado e, ainda, a determinação de como se estabelece a coordenação dos músculos envolvidos no movimento. Outros estudos têm demonstrado ainda a utilidade de se mensurar a força de mordida de sujeitos com desordens temporomandibulares, como um método adicional para se compreender a função dos músculos mastigatórios dos mesmos. O objetivo geral desse trabalho foi analisar e comparar a atividade de pares de músculos por meio de eletromiografia, durante provas de apertamento dental e de mastigação, além de analisar o desempenho dos músculos mastigatórios pela mensuração da força de mordida, antes e após o tratamento com placa oclusal, realizando ainda para ambos uma análise de confiabilidade dos testes (repetibilidade). A amostra foi composta por 15 sujeitos com desordem temporomandibular e 20 sujeitos controle, sem sinais ou sintomas de desordens temporomandibulares, segundo a classificação proposta pelo protocolo do Research Diagnostic Criteria for Temporomandibular Disorders. Os exames eletromiográficos e de força de mordida foram realizados no Laboratório de Pesquisa em Eletromiografia do Sistema Estomatognático. Foram encontradas diferenças estatísticas no índice POCmm, entre os grupos DTMi e DTMf, para o teste estático; no índices ciclo e frequência, ambos do lado esquerdo, entre os grupos DTMi e DTMf, para o teste dinâmico; e entre os grupos Controle e DTMi para os testes de força de mordida. Além disso, foi encontrada uma concordância estatisticamente significativa entre os dados de força de mordida, POC Médio e tors. Obteve-se com este estudo a melhor compreensão do diagnóstico das DTMs por meio da análise instrumental, conferindo um sentido biológico à eletromiografia de superfície e à avaliação da força de mordida, nos casos de desordens temporomandibulares. / The diagnosis of temporomandibular disorders is based on the information collected about symptoms during clinical examination of the occlusion and radiological examinations of the temporomandibular joints. In the search for better understanding of the pathophysiology that affects the muscles of the stomatognathic system, electromyographic analysis has been included in many studies because allows the identification of when and how a muscle is activated and also the determination of how the coordination of muscles is involved in movement. Other studies have also demonstrated the usefulness of measuring bite force of subjects with temporomandibular disorders, as an additional method for understanding the function of the masticatory muscles of the same. The aim of this study was to analyze and compare the activity of pairs of muscles by electromyography during clenching and chewing tests, and analyze the performance of masticatory muscles by measuring the bite force before and after treatment with occlusal splints, and still performing, for both, a reliability analysis of the tests (repeatability). The sample consisted of 15 subjects with temporomandibular disorder and 20 control subjects without signs or symptoms of temporomandibular disorders according to the classification proposed by the protocol of the Research Diagnostic Criteria for Temporomandibular Disorders. The electromyographic examinations and bite force were performed at the Laboratory of Research in Electromyography of the Stomatognathic System. Significant differences were found in the index POCmm among the groups DTMi and DTMf, for the static test; for the index cycle and frequency, both on the left side, among groups DTMi and DTMf for the dynamic test; and among the control and DTMi groups for the bite force test. In addition, we found a statistically significant correlation between the bite force data, POC Médio and tors. In the end, this study provided a better understand of the diagnosis of TMD by instrumental analysis, providing a biological sense to the surface electromyography and to the evaluation of bite force in cases of temporomandibular disorders.

A corrida de rua é descrita como uma atividade aeróbica intensa que atualmente envolve milhões de adeptos. A prática regular desta modalidade esportiva promove alterações nos músculos estriados esqueléticos fato que despertou o interesse em analisar, por meio da eletromiográfica (EMG - Myosystem), seu efeito sobre a atividade dos músculos do sistema estomatognático masseter e temporal em diferentes posições posturais da mandíbula, além de sua espessura por meio da ultrassonografia (Ultrassom portátil SonoSite Titan Nacionalizado), como também, a força de mordida máxima utilizando o dinamômetro digital modelo IDDK- Kratos posicionado na região dos primeiros molares. Foram avaliados 40 indivíduos adultos com idades entre 18 a 65 anos, de ambos os gêneros sem alterações clínicas do sistema estomatognático divididos em dois grupos: Grupo I Corredores e Grupo II Controle, pareados sujeito a sujeito. As médias eletromiográficas foram tabuladas e submetidas à análise estatística utilizando Teste t (SPSS 19.0). Os resultados evidenciaram diferenças significantes (p<0,05) para atividades eletromiográficas no grupo formado por indivíduos praticantes da corrida de rua ocorrendo um maior equilíbrio muscular funcional nas posturas clínicas analisadas. Nas condições em que este estudo foi desenvolvido os resultados indicam que a corrida de rua promoveu alterações significativas no sistema mastigatório. / Running is described as an intense aerobic activity which currently involves millions of fans. Regular practice of this sport promotes changes in skeletal muscles striated fact which aroused interest in analyzing through the electromyographic ( EMG - Myosystem ) , its effect on the activity of the muscles of the stomatognathic system masseter and temporalis muscles in different positions mandible posture , plus its thickness by ultrasonography (SonoSite Titan portable Ultrasound Nationalized ) , as well as the maximum bite force using a digital dynamometer model IDDK Kratos - positioned in the region of the first molars . We evaluated 40 adults aged 18-65 years, of both genders without clinical alterations of the stomatognathic system divided into two groups: Group I Runners and Group II Control matched each subject. The average EMG were tabulated and subjected to statistical analysis using t Test (SPSS 19.0). The results showed significant differences (p < 0.05) in EMG activity for group of individuals practicing the street race occurring more functional muscle balance postures analyzed clinical. In the conditions in which this study was conducted the results indicate that the road race promoted significant changes in the masticatory system.

The relationship between form and function is often used to elucidate the biological role of a structure. Hammerhead sharks offer a unique opportunity to study form and function through phylogeny. Because sphyrnid sharks display a range of cranial morphologies this group can be used to address questions about the evolution of cranial design and investigate the effects of changes in head morphology on feeding structures and bite force. Geometric morphometrics, volumetric analyses, morphological dissections, and phylogenetic analyses of the cephalofoil were used to gain insight into changes in cranial design through evolutionary history. External morphometrics and internal volumetric analyses indicated that while the external shape of the cephalofoil and placement of the sensory structures is variable through evolutionary history, the volumes of the internal cranial elements do not change. Constructional constraints within the cephalofoil were confined to sensory structures while feeding morphology remained relatively unchanged. Analysis of the morphology and biomechanics of the feeding apparatus revealed that through phylogeny the feeding system does not change among sphyrnid species. However, size-removed bite force was lower than predicted for all sphyrnid species except Sphyrna mokarran. Despite differences in head morphology between sphyrnid and carcharhinid sharks, the feeding bauplan is conserved in sphyrnid sharks with few changes to the feeding structures. Instead the chondrocranial and sensory structures are modified around the relatively static feeding core. Finally, the durophagous S. tiburo was found to consume hard prey in a manner that is biomechanically and morphologically different from other durophagous fishes. Furthermore, the diet of S. tiburo is constrained by the properties of its preferred prey.

The hellbender (Cryptobranchus alleganiensis) is a salamander that grows over a large range of body sizes (2-74 cm total length) making it an ideal organism for examining the effects of body size on morphology and performance. The goal of this study is to investigate the morphology changes over ontogeny and change in feeding ability. Cryptobranchus feeds on small aquatic insects as juveniles and shifts to crayfish as they get larger. Morphology can be expected to change as an organism grows larger, and because morphology and performance are closely linked, this morphological change can result in a change in feeding ability. Cryptobranchus alleganiensis are primarily aquatic salamanders that utilize both suction feeding and biting behaviors. I hypothesize bite force would increase with positive allometry reflecting a possible dietary shift during ontogeny in which larger Cryptobranchus favor crayfish. Because suction is the primary mode of feeding making it an important aspect of feeding throughout ontogeny, suction index was hypothesized to scale with isometry. Fourteen preserved specimens (11.9-34.5 cm SVL) were used to investigate the effects of scaling on suction potential and estimated bite force. Bite force was calculated using a 3D static equilibrium model and suction potential was calculated as suction index. Bite force scaled with positive allometry allowing the animals to bite harder relative to body mass with increasing body size, and suction index showed no effect of body size. Results of this study indicate that Cryptobranchus alleganiensis maintains suction performance across ontogeny allowing them to generate suction with similar ability ontogenetically, but increases its biting performance to cope with durophagous prey with a possible ontogenetic dietary shift.

The elasmobranch fishes possess a remarkable diversity of feeding mechanisms for a group containing relatively few species (~1200). The three most prevalent of these mechanisms involve prey capture during which the predator overtakes its prey (ram), prey is drawn into the mouth of the predator (suction), and relatively stationary consumption of sessile or substrate affixed prey (biting). Biomechanical modeling of cranial force distributions, in situ bite performance trials, and kinematic analysis of prey capture behaviors were employed to identify morphological and behavioral specializations and constraints associated with these feeding mechanisms in lemon Negaprion brevirostris (ram), whitespotted bamboo Chiloscyllium plagiosum (suction), and horn Heterodontus francisci (biting) sharks. Biomechanical modeling of the forces generated by the cranial musculature was used to theoretically estimate the maximum bite force and mechanical loadings occurring throughout the hyostyl ic jaw suspension mechanisms of each species, characterized by suspensory hyomandibular cartilages between the back of the jaws and cranium and anterior ligamentous attachments. To assess the mechanical factors involved in the evolution of elasmobranch jaw suspension mechanisms, the feeding mechanism of the sharpnose sevengill shark Heptranchias perlo was modeled as well. Heptranchias perlo possesses an ancestral amphistylic jaw suspension mechanism including non-suspensory hyomandibular cartilages, a large post-orbital articulation between the jaws and cranium, and anterior ligamentous attachments. Theoretical estimates of maximum bite force were compared to voluntary bite forces measured during in situ bite performance trials. Voluntary bite force measurements allowed the quantification of discrete behavioral attributes of bite force application in each species. To further assess the behavioral specializations associated with these feeding mechanisms, high-speed digital videography w as used to analyze the prey capture cranial kinematics of species. Collectively, these analyses have developed a morphological and behavioral basis from which to understand the functional diversity of the ram, suction, and biting feeding mechanisms in elasmobranchs.

O sistema estomatognático constitui entidade fisiológica e funcional integrada por um conjunto de órgãos e tecidos, cuja biologia e fisiopatologia são absolutamente interdependentes. A perda dental determina importantes alterações no sistema estomatognático, as quais afetam, particularmente, o osso, a mucosa bucal e a função muscular. A performance mastigatória deteriora com a perda dos dentes, pois esta depende das condições da dentição, que inclui o número de dentes presentes em oclusão funcional, o número de dentes posteriores em contato, as áreas funcionais de contato e o grau de maloclusão. Para que haja a reabilitação funcional do sistema estomatognático e, consequentemente, da função mastigatória em indivíduos com perdas dentais parciais e/ou totais, fatores importantes devem ser considerados, como a reabilitação protética e muscular. Considerando, ainda, ser relevante a influência da musculatura na reabilitação funcional do sistema estomatognático, é importante, avaliar o comportamento da musculatura mastigatória frente às diferentes reabilitações protéticas. Este estudo tem como objetivo analisar a atividade eletromiográfica, a espessura dos músculos masseter e temporal, a força de mordida e a eficiência mastigatória de indivíduos adultos reabilitados com diferentes tipos de prótese dental, e com isso traçar um padrão de comportamento muscular de acordo com os diferentes tipos de reabilitação. Os resultados deste trabalho permitem a avaliação integral do sistema estomatognático do ponto de vista morfológico e funcional. Os aspectos investigados objetivam facilitar diagnósticos e prognósticos, trazendo contribuições para a comprovação da qualidade e estabilidade dos tratamentos. / The stomatognathic system is a physiological and functional entity comprising a set of organs and tissues, whose biology and pathophysiology are absolutely interdependent. The tooth loss causes important changes in the masticatory system which affects bone, oral mucosa and muscle function. The masticatory performance deteriorates with tooth loss because it depends on the dentition, which includes the number of teeth present in functional occlusion, the number of posterior teeth in contact, the size of the functional areas of contact and degree of malocclusion. In order to have the rehabilitation of the stomatognathic system and consequently the masticatory function in patients with partial and / or complete tooth loss, important factors should be considered as muscle and prosthetic rehabilitation. Considering relevant the influence of the muscles in the rehabilitation of the stomatognathic system, the intention of this work was to evaluate the behavior of the masticatory muscles in different prosthetic rehabilitation. This study aims to analyze the electromyographic activity, the thickness of the masseter and temporal muscles, bite force and masticatory efficiency of adult individuals rehabilitated with different types of dental prosthesis, aiming to draw a pattern of muscle according to the different types of rehabilitation. These results allow full assessment of the stomatognathic system in terms of morphological and functional. The study focused aim to facilitate diagnosis and prognosis, bringing contributions to the quality and stability of treatments.

Submitted by AMANDA LAÍSA DE OLIVEIRA LIMA (mandynha_lima@hotmail.com) on 2018-10-02T12:43:40Z No. of bitstreams: 1 Dissertação Amanda Final 021018.pdf: 1207126 bytes, checksum: c3f584bdf06f67b99aaf8eb4f8b83883 (MD5) / Approved for entry into archive by Ceres Maria Carvalho Galvão de Freitas null (ceres@foar.unesp.br) on 2018-10-02T13:13:39Z (GMT) No. of bitstreams: 1 lima_alo_me_arafo_int.pdf: 1207126 bytes, checksum: c3f584bdf06f67b99aaf8eb4f8b83883 (MD5) / Made available in DSpace on 2018-10-02T13:13:39Z (GMT). No. of bitstreams: 1 lima_alo_me_arafo_int.pdf: 1207126 bytes, checksum: c3f584bdf06f67b99aaf8eb4f8b83883 (MD5) Previous issue date: 2018-06-05 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Grande parte dos pacientes reabilitados com próteses totais convencionais é insatisfeita devido a problemas com retenção e estabilidade, principalmente quando é usuária de próteses totais mandibulares. Uma opção de tratamento satisfatório é a utilização de próteses totais removíveis suportadas por implantes (overdentures), conectadas por meio de diferentes sistemas de encaixe. O objetivo neste estudo foi avaliar o efeito de dois diferentes sistemas de encaixes (O'ring e Locator) para overdenture mandibular retida por um implante sobre a autopercepção da saúde bucal, impacto da saúde bucal na qualidade de vida, força máxima de mordida e a eficiência mastigatória. Este estudo foi do tipo cross-over, composto por 28 participantes distribuídos igualmente em dois grupos de acordo com os critérios de inclusão e exclusão. Para avaliar o impacto da saúde bucal na qualidade de vida e a autopercepção da saúde bucal foram utilizados os questionários Ohip-Edent e GOHAI, respectivamente. Para a avaliação da força de mordida, utilizou-se um gnatodinamômetro, e em relação a eficiência mastigatória, utilizou-se cubos de silicone de condensação denso e amêndoas, mastigados por 30 ciclos, 40 ciclos e até o paciente se sentir “pronto para engolir”. A análise estatística dos dados foi realizada com os seguintes testes: Friedman e Wilcoxon (para os questionários utilizando uma média para as pontuações), t-student, análise de variância a dois fatores para medidas repetidas e Correlação de Pearson (força máxima de mordida e eficiência mastigatória). Nos questionários Ohip-Edent e GOHAI não foi observado diferença estatística com relação aos dois tipos de encaixes analisados. No teste de força máxima de mordida, o encaixe do tipo O’ring proporcionou uma força máxima de mordida superior quando comparado ao Locator (p=0,04), além disso, quanto maior esta força máxima de mordida, menor o número de ciclos mastigatórios realizados até o momento “pronto para engolir”, independente do alimento. No teste de eficiência mastigatória, observou-se que não houve diferença estatística em relação ao tipo de encaixe em ambos os alimentos (p>0,05), porém, pode-se afirmar que eficiência mastigatória foi diretamente proporcional a quantidade de ciclos mastigatórios somente para o alimento amêndoas (p<0,01). Assim, pode-se concluir que a força máxima de mordida foi influenciada positivamente pelo tipo de encaixe o’ring. / Most patients rehabilitated with conventional dentures feel dissatisfied due to problems with retention and stability, especially when they are user of mandibular conventional dentures. A satisfactory option of treatment is the use of removable total dentures supported by implants (overdentures), connected through different attachments systems. The aim this study was to evaluate with two different attachments systems (O-ring and Locator) for mandibular overdenture retained by a single implant on the self-perception of oral health, quality of life impact, maximum bite force, and masticatory efficiency. To evaluete impact of oral health on quality of life and self-perceived oral health were using the OHIP-Edent and GOHAI questionnaires, respectively. To avaluated bite force was using a gnathodynamometer, and with respect to masticatory efficiency, was using a dense condensation silicone cubes and almonds with 30 cycles, 40 cycles until the patient feel "ready to swallow". Statistical analysis of data was performed with tests subsequent: Friedman and Wilcoxon (to questionnaires using a mean to the scores), t-student, two-way ANOVA test for repeated measures and Pearson's Correlation (maximum bite force and masticatory efficiency). In the questionnaires OHIP-Edent and GOHAI. it was not observed statistical diference in relation to two types of attachments analyzed. In the maximum bite force test, the attachment of type O'ring provided a maximum bite force higher when compared the Locator attachment (p=0,04), in addition, the higher this maximum bite force, lower the number of masticatory cycle realized up to the moment "ready to swallow", independent of the food. In masticatory efficiency test, was observed wich not have statistical diference in relation the type of attachment in both the food (p>0.05) but can afirm that masticatory efficiency was directly proportional the quantity of masticatory cycles only to almonds (p<0.01). Therefore, can conclude that the choice of attachment of type O'ring to overdentures influenced on maximum bite force / 2016/17688-3