No description available.

Pinyon-juniper woodland encroachment threatens ecosystem function and diversity on sagebrush steppe. Decreased fire frequency likely favors proliferation of pinyon-juniper woodlands and subsequent decline in desirable understory species. Increased tree cover produces hazardous canopy fuel loads that contribute to severe crown fires and threaten life and property at the wildland-urban-interface. Mechanical mastication converts large canopy fuels into small woody debris, altering wildfire dynamics from a potential crown fire to a more controllable surface fire. We measured fuel loading and cover on untreated, masticated, and masticated + burned treatments on 30-m transects within 30 X 33-m subplots, representing 45 different sites throughout Utah. All variables were analyzed using mixed-model analysis of covariance with untreated or pretreatment tree cover as the covariate. Shredding trees reduced large-diameter fuels to primarily 10-hour fuels (6.4-25.4 mm diameter). Reduced fuel sizes, fuel redistribution, and fuelbed compactness resulting from mastication treatments can aid wildfire suppression. Masticated + burned treatments effectively reduced woody surface fuel loading to that of pretreatment conditions. Prescribed burning could be used outside the growing season in cool-weather, high-moisture conditions to remove surface fuels, mitigating lethal soil heating and plant mortality. Shrub loading was not adversely affected by mastication treatments, but was significantly reduced with masticated + burned treatments. Masticated and masticated + burned treatments significantly increased herbaceous fuel loading. Treating at lower tree cover values reduced fuel buildup, and provided more opportunity for a positive herbaceous response. Fuel loading estimates measured in this study were provided to populate fire behavior models for mastication treatments on our study sites when such models become available.

No description available.

No / The ability of prisms to effectively dissipate contact stress at the surface will influence wear rates in teeth. The aim of this investigation was to begin to quantify the effect of prism orientation on surface stresses. Seven finite element models of enamel microstructure were created, each model differing in the angulation of prism orientation with regard to the wear surface. For validation purposes, the mechanical behavior of the model was compared with published experimental data. In order to test the enamel under lateral loads, a compressed food particle was dragged across the surface from the dentino-enamel junction (DEJ) towards the outer enamel surface (OES). Under these conditions, tensile stresses in the enamel model increased with increases in the coefficient of friction. More importantly, stresses were found to be lowest in models in which the prisms approach the surface at lower angles (i.e., more obliquely cut prisms), and highest when the prisms approached the surface at 60° (i.e., less obliquely cut). Finally, the direction of travel of the simulated food particle was reversed, allowing comparison of the difference in behavior between trailing and leading edge enamels (i.e., when the food particle was dragged either towards or away from the DEJ). Stresses at the trailing edge were usually lower than stresses at the leading edge. Taken together with what is known about prism orientation in primate teeth, such findings imply greater wear resistance at the intercuspal region and less wear resistance at the lateral enamel at midcrown. Such findings appear to be supported by archeological evidence.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

A definição de valores de referência a partir de sujeitos saudáveis é fundamental como parâmetro para o diagnóstico na área da saúde. Os objetivos deste estudo foram estabelecer valores de referência para a condição miofuncional orofacial, para as forças orofaciais e para a eficiência mastigatória, por meio de um escore de padronização e analisar as relações entre as variáveis, após estabelecer um índice de desempenho para as forças orofaciais e eficiência mastigatória. De um total de 316 sujeitos, foram selecionados 50 participantes, 21 homens e 29 mulheres, de 18 a 40 anos, sem desordem temporomandibular, sem distúrbio miofuncional orofacial e em normoclusão (classe I de Angle). Os sujeitos foram avaliados por meio do Protocolo de Avaliação Miofuncional Orofacial com Escores (AMIOFE) para investigação da condição miofuncional orofacial. As forças isométricas máximas de mordida direita e esquerda, das bochechas direita e esquerda, da língua na região anterior e dorso e dos lábios foram avaliadas por um dinamômetro eletrônico Kratos® e os valores foram registrados em Newtons (N). Para todas as forças foram realizadas 3 medidas e obtida a média. A eficiência mastigatória foi analisada pelo método colorimétrico com beads, obtendo-se a concentração de fucsina em micrograma por mililitro (µg/ml). A eficiência foi avaliada em situação de mastigação habitual, mastigação unilateral direita e esquerda, durante 20 segundos cada. Para todas as variáveis foi calculado o escore Z, para identificação de seus valores de referência e os pontos de corte que diferenciou os sujeitos normais e alterados; os valores das forças orofaciais e da eficiência mastigatória destes sujeitos foram transformados em índice de desempenho, para 34 sujeitos da amostra que foram considerados normais. O erro casual do método foi calculado para todas as variáveis. Para análise estatística foi utilizado o teste de correlação de Spearman, por meio do Programa MedCalc® e o nível de significância adotado foi p<0,05. Os valores médios de referência estabelecidos a partir do escore Z foram: para a condição miofuncional orofacial 95,79 ± 3,74; para a média da força de mordida direita e esquerda 431,08 ± 138,01N; para a média da força de bochechas direita e esquerda 17,92 ± 7,44N; para a força de língua na região anterior 9,45 ± 4,01N; para a força de língua na região de dorso 13,44 ± 5,46N; para a força de lábios 4,31 ± 1,48N; para a eficiência mastigatória habitual 0,72 ± 0,31µg/ml; para a eficiência mastigatória a direita 0,71 ± 0,30µg/ml e para a eficiência mastigatória a esquerda 0,78 ± 0,37µg/ml. Não foram encontradas correlações entre os índices de desempenho das forças orofaciais e da eficiência mastigatória (r=0,102, p>0,05), entre o índice de desempenho das forças orofaciais e a condição miofuncional orofacial (r=-0,005, p>0,05), nem entre o índice de desempenho da eficiência mastigatória e a condição miofuncional orofacial (r=0,059, p>0,05). Não foi observado neste estudo relação entre a biomecânica orofacial e a eficiência mastigatória. / The definition of reference values of healthy subjects is a fundamental parameter for the diagnosis in health. The aims of this study were to establish reference values based on standardized score for the orofacial myofunctional condition, for the orofacial strength and for the masticatory efficiency, and to analyze the relationships between them, after establishing a performance index for orofacial strength and masticatory efficiency. From a total of 316 subjects, 50 participants were selected, 21 men and 29 women, ranging from 18 to 40 years old, without temporomandibular disorder, no orofacial myofunctional disorder and presenting normal occlusion. Subjects were assessed using the Orofacial Myofunctional Evaluation Protocol with Scores (OMES) to investigate the orofacial myofunctional condition. The orofacial strength evaluated were maximal isometric bite forces on the right and left sides, maximal isometric cheeks strength on the right and left sides, maximal isometric tongue strength on the anterior and dorsum region and maximal isometric lips strength using an electronic dynamometer Kratos®. The values were recorded in Newton (N). The mean value of three trials of each orofacial strength was obtained. The masticatory efficiency was analyzed by colorimetric method with beads. The fuchsine concentration in micrograms per milliliter (µg/ml) was obtained. The masticatory efficiency was evaluated in three conditions: habitual, right and left unilateral chewing, for 20 seconds each one. For all variables, the Z scores were calculated to determine the reference values and cutoff values that differentiate the normal and abnormal subjects. The orofacial strength and masticatory efficiency values were transformed into the performance index, for 34 participants that were defined as normal subjects. The random error was calculated for all variables. Statistical analysis was performed using Spearman correlation test, using the MedCalc® program and the level of significance was p<0.05. The reference values (mean and standard deviation), established from the Z score, were 95.79 ± 3.74 for the orofacial myofunctional condition; 431.08 ± 138.01N for the maximal isometric bite force; 17.92 ± 7.44N for the maximal isometric cheeks strength; 9.45 ± 4.01N for the maximal isometric tongue strength in the anterior region; 13.44 ± 5.46N for the maximal isometric tongue strength in the dorsum region; 4.31 ± 1.48N for the maximal isometric lips strength; 0.72 ± 0.31µg/ml for the habitual masticatory efficiency; 0.71 ± 0.30µg/ml for the right masticatory efficiency, 0.78 ± 0.37µg/ml for the left masticatory efficiency. No correlations were found neither between the orofacial strength performance index and masticatory efficiency performance index (r=0.102, p>0.05), the orofacial strength performance index and orofacial myofunctional condition (r=-0.005, p>0.05), nor between the masticatory efficiency performance index and orofacial myofunctional condition (r=0.059, p>0.05). There was no relationship between the biomechanics orofacial and masticatory efficiency in this study.

Na literatura, há apenas um protocolo de avaliação miofuncional orofacial validado, o Protocolo de avaliação miofuncional orofacial com escores (AMIOFE) (Felício e Ferreira, 2008). Apesar da reconhecida importância da avaliação perceptiva esta apresenta certas limitações devido à sua subjetividade, além disso, a maior precisão nos resultados é obtida com escalas numéricas de avaliação mais amplas. As escalas numéricas e o número de itens a serem avaliados pelo protocolo AMIOFE foram ampliados, visando possibilitar a detecção e registro de pequenas diferenças nas características físicas e nos comportamentos orofaciais entre-sujeitos e variações intra-sujeito ao longo do tempo. Os objetivos deste estudo foram descrever o Protocolo AMIOFE ampliado (AMIOFE-A), analisar a validade, a confiabilidade e a concordância, bem como investigar os valores de sensibilidade, de especificidade e preditivos do protocolo proposto. A amostra para o presente estudo foi composta de imagens registradas e vídeo de 50 crianças, 25 meninos (média de idade=8,4 anos, desvio padrão=1,8) e 25 meninas (media de idade=8,2 anos, desvio padrão=1,7). Três fonoaudiólogas preparadas para avaliação miofuncional orofacial foram escolhidas após a análise da habilidade delas para usar o protocolo AMIOFE. Para a análise da validade de critério do protocolo AMIOFE-A as crianças foram avaliadas individualmente pela análise das imagens gravadas em DVD pelos protocolos AMIOFE e AMIOFE-A. Para a complementação da validade de critério foi realizada a testagem da confiabilidade e da concordância de aplicação e/ou de interpretação do AMIOFE-A. Foram empregados os testes estatísticos de correlação de Spearman e o método de confiabiliadade Split-half, com nível de significância a 0,05, também foi calculado o coeficiente Kappa ponderado linear (Kw), os valores de sensibilidade (S), a especificidade (E), os valores preditivos (VP+ e VP-) e a prevalência (P). Houve correlação estatisticamente significante entre as avaliações realizadas com os protocolos AMIOFE e AMIOE-A, os valores, de acordo com os examinadores, foram E1 (r=0,81, p<0,01), E2 (r=0,79, p<0,01) e E3 (r=0,94, p<0,01). A concordância entre os protocolos foram para E1 de 0,89, de 0,88 para E2, e de 0,97 para E3. Os valores dos coeficientes de correlação e de confiabilidade entre o testereteste com o AMIOFE-A foram: E1 (r=0,86, 0,93), E2 (r=0,75, 0,86) e E3 (r=0,80, 0,89). Os valores dos coeficientes de correlação e de confiabilidade entre examinadoras com o AMIOFE-A foram: E1 x E2 (r=0,74, 0,84), E1 x E3 (r=0,70, 0,83), todos com p<0,01. A força de concordância do Kw para a aplicação do protocolo AMIOFE-A, tanto para as análises teste-reteste quanto para as entre examinadores, predominantes foram moderada e boa. Para o protocolo AMIOFE-A foram encontradas médias dos valores de S de 0,91, de E de 0,77, dos VP+ de 0,87 e VP- de 0,85. A prevalência média dos distúrbios miofuncionais orofaciais foi de 0,58. Os resultados permitiram concluir que o Protocolo AMIOFE-A é válido e confiável para avaliação miofuncional orofacial e possui boas sensibilidade e especificidade, bem como bons valores preditivos positivo e negativo. / In the literature, there is only one instrument validated for the clinical evaluation of the orofacial myofunctional condition of children, the Orofacial Myofunctional Evaluation Protocol with Scores (OMES) (Felício and Ferreira, 2008). In spite of recognized importance of the perceptible evaluation this present some limitations because your subjectivity, and, the increase of precision in the results is provided with numerical scales with more information. The numerical scales and the items number evaluations for OMES protocol were extended, with aim for possibility the detection and note of difference smalls in the characteristics physics and in the orofacial behaviors entre-subjects and variation intra-subject in the time. This study had with objective describe the OMES protocol extended (OMES-E), analyze the validity, the reliability and the correlation, as well as investigate the values of sensitivity, of specificity and predictive values of the OMES-E. The sample for the study compounded of images and videos of 50 children, 25 boys (mean age=8.4 years, standard deviation=1.8) and 25 girls (mean age=8.2 years, standard deviation=1.7). Three speech therapists (E1, E2 and E3) properly calibrated in orofacial myofuncional evaluation were choosed after analysis of ability of the examiners in to use the OMES protocol. To analysis of criterion validity of OMES-E protocol the children were evaluated individually for the analysis of images recorded on DVD for the protocols OMES and OMES-E. To complement the criterion validity was carried out the test of the correlations and of the reability of the applications and/or of the interpretation of the OMES-E. Statistical analysis was performed using the Statistics software based on the split-half reliability method, the level of significance was set at 0.05, Spearman correlation coefficient, the coefficient Kappa weighted linear (Kw), the sensitivity (S), specificity (E), predictive values (VP+ e VP-) and the prevalence (P) were also calculated. Was statistically significant correlation between the evaluations with the OMES and OMES-E protocols, the values, in agreement with the examiners, were E1 (r=0.81, p<0.01), E2 (r=0.79, p<0.01) and E3 (r=0.94, p<0.01). The reliability between protocols were to E1 0.89, to E2 0.88, and to E3 0.97. The correlations and reliability values between the testretest with the OMES-E were: E1 (r=0,86, 0,93), E2 (r=0.75, 0.86) e E3 (r=0.80, 0.89). The correlations and reliability values between examiners with the OMES-E were: E1 x E2 (r=0.74, 0.84), E1 x E3 (r=0.70, 0.83), all with p<0.01. The Kw strength of agreement to the OMES-E protocol apply, for the analyses test-retest and to analyses between examiners, predominant were moderate and good. To the OMES-E protocol were found mean values of 0.91 for the S, of 0.77 for the E, of 0.87 for the VP+ and of 0.85 for the VP-. The prevalence mean of myofuncional disorder was 0.58. The OMES-E protocol proved to be a valid and reliable instrument for orofacial myofuncional evaluation and have goods sensitivity and specificity, as well as predictive values.

O câncer de cabeça e pescoço pode acarretar consequências aos indivíduos, como prejuízos na saúde oral e na performance mastigatória devido à localização do tumor ou pelo próprio tratamento, dificultando o consumo alimentar, resultando em desnutrição e prejuízos na qualidade de vida mesmo após o término do tratamento. O presente estudo teve como objetivo verificar a relação entre a função mastigatória, a condição nutricional, a saúde oral e a qualidade de vida em saúde oral em indivíduos após o tratamento de câncer de cabeça e pescoço. Foram avaliados 20 indivíduos que atenderam aos critérios de inclusão propostos, por meio da eletromiografia de superfície (EMGs) dos músculos masseter e temporal durante a mastigação unilateral; da avaliação antropométrica do estado nutricional, com peso, estatura, índice de massa corporal (IMC), pregas cutâneas; da avaliação dietética, através do recordatório alimentar de 24 horas; da avaliação da saúde oral, considerando o índice de atividade de cárie (CPOD), índice periodontal comunitário (CPI) e avaliação de uso e necessidade de prótese; da qualidade de vida com o instrumento Oral Health Impact Profile (OHIP-14). A EMGs demonstrou na avaliação da função mastigatória, na prova de Máxima Contração Voluntária (MCV) valores próximos de 100% para uma simetria perfeita da atividade muscular, valor de 9,07% para ausência de deslocamento dos músculos mastigatórios e o índice de atividade obteve maior prevalência dos músculos temporais. Na mastigação unilateral, os pacientes apresentaram padrão assimétrico na mastigação, assimetria entre os músculos masseteres e temporais para a mastigação do lado esquerdo, além de um predomínio do lado de trabalho. Na avaliação antropométrica 20% apresentaram baixo peso e 45% excesso de peso no IMC, enquanto a CB indicou 15% obesidade e 40% algum grau de desnutrição, confirmada na CMB. Para a porcentagem de gordura 20% estavam muito baixo e 30% acima do recomendado. Na avaliação dietética, 65% apresentaram consumo do valor energético total acima do recomendado, os macronutrientes estavam adequados em 70%, 90% e 60% para carboidrato, proteína e lipídeo respectivamente, os pacientes apresentaram consumo adequado: Ferro, Fósforo, Zinco, Vitamina B12 e E, os micronutrientes acima foram: Magnésio e Sódio. Foi verificado consumo baixo da necessidade para os micronutrientes: Potássio, Cálcio, Selênio, Vitamina D, A e C. Houve correlações entre o menor consumo de gordura e maior simetria da atividade muscular. A avaliação da saúde oral mostrou que 55% tinham baixa e 45% muito baixa atividade de cárie, 50% com sangramento gengival, 60% presença de cálculo e 35% bolsa periodontal de 4-5mm, 35% e 40% necessitavam de utilizar algum tipo de prótese superior e inferior, respectivamente. O OHIP-14 indicou fraco impacto da qualidade de vida na saúde oral para 55% dos participantes. Na saúde oral, quanto menor a necessidade de prótese inferior e quanto menor atividade de cárie maior simetria de atividade muscular na mastigação, enquanto maior necessidade de prótese resultou em mais ciclos mastigatórios. Portanto, após termino do tratamento de câncer de cabeça e pescoço foram encontrados prejuízos na mastigação, no estado nutricional, na ingestão alimentar e na saúde oral, existindo relação entre a atividade muscular durante a função mastigatória, a condição dietética e a saúde oral, indicando a necessidade do atendimento multidisciplinar voltado a esses pacientes. / The head and neck cancer can cause consequences to individuals, as losses in oral health and mastigatory function due to the location of the tumor our the treatments, difficulting food intake so, therefore cause malnutrition and losses in quality of life, even after end of treatment. The aim of the present study is checking the relation between the mastigatory function, with nutritional status, with oral health and with quality of life in oral health, in individuals after of head and neck cancer treatment. The sample consisted of 20 individuals that attended the criteria of inclusion and exclusion, through the surface electromyography (EMGs) of mastication muscles, masseter and temporal was performed during unilateral chewing; the nutrition status, with weight, height, Body Mass Index (BMI), skinfold thickness, dietary assessment, through the 24-hour dietary recall; the oral health assessment, DMF index, community periodontal index (CPI) and assessment of the use and need of a prothesis; the quality of life with questionnaire Oral Health Impact Profile (OHIP- 14). The EMGs showed of the masticatory function in the test of Maximum voluntary teeth clenching (MVC), values of 100% for a perfect symmetry of muscle activity, 9,07% for the absence of masticatory muscle data and index for the temporal muscle had prevalence of temporal muscles. Unilateral chewing showed asymmetrical standard in chewing asymmetrical between the muscles masseter and temporal to chewing on the left side and predominance of working-side. The anthropometric evaluation indicated 20% malnutrition and 45% overweight in BMI, whereas the CB indicated 15% overweight and 40% some degree of malnutrition, confirmed in CMB. The body fat 20% were a lot below and 30% above recommended. Dietary assessment showed that carbohydrate, protein and lipid were adequate with 70%, 90% and 60% respectively. The patients showed adequate intake: iron, phosphorus, zinc, vitamin B12 and E, the higher intake of sodium and magnesium, and lower intake of, potassium, calcium, selenium, vitamin D, A and C. The oral health assessment indicated that 55% were lower and 45% a lot lower caries activity, 50% with gingival bleeding, 60% stone and 35% periodontal pocket of 4-5 mm, 35% and 40% needed the use some type of superior and inferior prosthesis, respectively. The OHIP-14 indicated weak impact of quality of life in oral health to 55% of sample. Had correlated between lower intake of fat, higher symmetry of muscle activity in chewing. The oral health, how lower the need the prosthesis inferior and how lower carie activity higher symmetry of muscle activity in chewing, while higher need of prosthesis indicated in more masticatory cycles. Therefore, after end of treatment of head and neck cancer was found consequences in mastication, nutritional status, food intake and oral health, existed relation between muscle activity during the masticatory function the dietetics and the oral health, indicated the need of multidisciplinary activity with emphasis on these patients.

Made available in DSpace on 2014-12-17T15:43:53Z (GMT). No. of bitstreams: 1 RachelGC_DISSERT.pdf: 1470565 bytes, checksum: 48e0a612bd38dde085d137202fb35011 (MD5) Previous issue date: 2013-03-21 / Edentulous patients with complaint about mandibular conventional denture might experience poor masticatory function and negative impact of oral health on quality of life. The aim of this controlled clinical trial was to evaluate the effect of mandibular overdenture on oral health-related quality of life and masticatory efficacy in patients wearing mandibular complete dentures. The edentulous patients (n=16) were rehabilitated with new maxillary and mandibular complete dentures and, after 3 months, mandibular overdentures retained by 2 implants (bar-clip system) were fabricated. The Brazilian version of OHIP-Edent questionnaire was used to assess the oral healthrelated quality of life. Masticatory efficacy was evaluated through a colorimetric method with chewing capsules. The mean OHIP-Edent score was 8.5 with conventional dentures and 2.0 with mandibular overdenture, which means a positive impact of oral health on quality of life with overdentures (p=0.001). The mean absorbance for masticatory efficacy was 0.025 for conventional dentures and 0.073 for overdentures. There was statistically significant difference for masticatory efficacy before and after implants rehabilitation (p=0.003). However, there was no correlation between masticatory efficacy and OHIP (p>0.05). So, mandibular overdenture retained by 2 implants improved the quality of life and masticatory efficacy of edentulous patients with complaint about mandibular conventional complete dentures / Pacientes ed?ntulos que relatam problemas com o uso da pr?tese total convencional mandibular podem ter a fun??o mastigat?ria prejudicada, bem como impacto negativo da sa?de bucal na qualidade de vida. O objetivo deste ensaio cl?nico controlado foi avaliar o efeito da reabilita??o com sobredentudura mandibular sobre o impacto da sa?de oral na qualidade de vida e sobre a efici?ncia mastigat?ria em pacientes usu?rios de pr?tese total convencional mandibular. Os pacientes desdentados totais (n = 16) foram reabilitados com novas pr?teses totais convencionais na maxila e na mandibula e, ap?s 3 meses, as pr?teses mandibulares foram convertidas em sobredentaduras retidas por 2 implantes (sistema barra clipe). A vers?o brasileira do question?rio OHIP-Edent foi utilizada para avaliar o impacto da sa?de oral na qualidade de vida. A efici?ncia mastigat?ria foi avaliada atrav?s do m?todo colorim?trico com o uso da c?psula mastigat?ria. O valor da mediana do OHIP-Edent com o uso de pr?teses totais convencionais foi 8,5 pontos, ap?s a convers?o da pr?tese total convencional mandibular em sobredentadura o valor da mediana do OHIP-Edent foi 2 pontos, resultando em um impacto positivo da sa?de oral na qualidade de vida ap?s o tratamento com as sobredentaduras (p = 0,001). A efici?ncia mastigat?ria com o uso de pr?teses totais convencionais obteve valor de absorb?ncia com mediana de 0,025 e ap?s a sua convers?o em sobredentadura retida por 2 implantes, a mediana da absorb?ncia foi 0,073. Houve diferen?a estat?stica significativa entre a efici?ncia mastigat?ria dos pacientes reabilitados com pr?tese total dupla antes e ap?s a interven??o com implantes (p=0,003). No entanto, n?o foi observada nenhuma correla??o entre efici?ncia e OHIP (p>0,05). Pacientes desdentados totais insatisfeitos com a pr?tese total convencional mandibular, ap?s a reabilita??o com sobredentadura mandibular retida por dois implantes, melhoram a qualidade de vida e a efici?ncia mastigat?ria

The focus of this thesis was to study an action that humans perform regularly, namely, to hold a morsel between the teeth and split it into smaller pieces. Three different issues related to this biting behavior were addressed:  (1) the effect of redu­c­ed perio­dontal tissues on food holding and splitting behavior; (2) the behavioral conse­quences of performing different bite tasks with different functional requirements, i.e., to split a peanut half resting on a piece of chocolate or to split both the peanut and the chocolate; and (3) the reflex modulations resul­ting from such a change in the intended bite action. The main conclusions from the experi­mental studies were the following: First, perio­dontitis, an inflam­matory disease that destroys the peri­o­dontal ligaments and the embedded perio­dontal mechanoreceptors, causes significant impairments in the masticatory abili­ty: the manipulative bite forces when holding a morsel are elevated compared to a matched control population and the bite force development prior to food split is altered. These changes are likely due to a combination of reduced sensory informa­tion from the damaged ligaments and to changes in the bite stra­tegy secon­d­ary to the unstable oral situation. Second, people exploit the anatomy of jaw-closing muscles to regulate the amount of bite force that dissipates following a sudden unloading of the jaw. Such control is necessary because without mechanisms that quickly halt jaw-closing movements after sudden unloading, the impact forces when the teeth collide could otherwise damage both the teeth and related soft tissues. Splitting a piece of chocolate, for instance, regularly requires &gt;100N of bite force and the jaws collide within 5 ms of a split. On the other hand, when biting through heterogeneous food, the bite force needs to be kept high until the whole morsel is split. The required regulation is achieved by differen­tial­ly engaging parts of the masseter muscles along the anteroposterior axis of the jaw to exploit differences between muscle portions in their bite force generating capa­ci­ty and muscle shortening velocity. Finally, the reflex evoked by suddenly unloading the jaw—apparent only after the initial bite force dissipation—is modulated according to the bite intention. That is, when the intention is to bite through food items with multiple layers, the reflex response in the jaw opening muscles following a split is small, thus minimizing the bite force reduction. In contrast, when the intention is to rapidly decrease the bite force once a split has occurred, the reflex response is high. This pattern of reflex modulation is functionally beneficial when biting through heterogeneous food in a smooth manner. The presented studies show the significance of integrating cogni­tive, physiological and anatomical aspects when attempting to understand human masticatory control.