Comportamiento Mecánico de un Premolar Humano Sano Sometido a Fuerzas Funcionales y Disfuncionales en un MEF / Mechanical Behavior of a Healthy Human Premolar Subjected to Functional and Dysfunctional Forces in a FEM

El propósito de este estudio fue analizar el comportamiento mecánico de la estructura dental sana de un primer premolar inferior humano sometido a fuerzas funcionales y disfuncionales en diferentes direcciones. Se buscó comprender, bajo las variables contempladas, las zonas de concentración de esfuerzos que conllevan al daño estructural de sus constituyentes y tejidos adyacentes. Se realizó el modelo 3D de la reconstrucción de un archivo TAC de un primer premolar inferior, que incluyó esmalte, dentina, ligamento periodontal y hueso alveolar considerando tres variables: dirección, magnitud y área de la fuerza aplicada. La dirección fue dirigida en tres vectores (vertical, tangencial y horizontal) bajo cuatro magnitudes, una funcional de 35 N y tres disfuncionales de 170, 310 y 445 N, aplicadas sobre un área de la cara oclusal y/o vestibular del premolar que involucró tres contactos estabilizadores (A, B y C) y dos paradores de cierre. Los resultados obtenidos explican el fenómeno de combinar tres vectores, cuatro magnitudes y un área de aplicación de la fuerza, donde los valores de esfuerzo efectivo equivalente Von Mises muestran valores máximos a partir de los 60 MPa. Los valores de tensión máximos se localizan, bajo la carga horizontal a 170 N y en el proceso masticatorio en la zona cervical, cuando la fuerza pasa del 60 %. Sobre la base de los hallazgos de este estudio, se puede concluir que la reacción de los tejidos a fuerzas funcionales y disfuncionales varía de acuerdo con la magnitud, dirección y área de aplicación de la fuerza. Los valores de tensión resultan ser más altos bajo la aplicación de fuerzas disfuncionales tanto en magnitud como en dirección, produciendo esfuerzos tensiles significativos para la estructura dental y periodontal cervical, mientras que, bajo las cargas funcionales aplicadas en cualquier dirección, no se generan esfuerzos lesivos. Esto supone el reconocimiento del poder de detrimento estructural del diente y periodonto frente al bruxismo céntrico y excéntrico.

SUMMARY: The purpose of this study was to analyze the mechanical behavior of the healthy dental structure of a human mandibular first premolar subjected to functional and dysfunctional forces in different directions. It was sought to understand, under the contemplated variables, the areas of stress concentration that lead to structural damage of its constituents and adjacent tissues. The 3D model of the reconstruction of a CT file of a lower first premolar was made, which included enamel, dentin, periodontal ligament and alveolar bone considering three variables: direction, magnitude and area of the applied force. The direction was directed in three vectors (vertical, tangential and horizontal) under four magnitudes, one functional of 35 N and three dysfunctional of 170, 310 and 445 N, applied to an area of the occlusal and/or buccal face of the premolar that involved three stabilizing contacts (A, B and C) and two closing stops. The results obtained explain the phenomenon of combining three vectors, four magnitudes and an area of force application, where the values of effective equivalent Von Mises stress show maximum values from 60 MPa. The maximum tension values are located under the horizontal load at 170 N and in the masticatory process in the cervical area, when the force exceeds 60%. Based on the findings of this study, it can be concluded that the reaction of tissues to functional and dysfunctional forces varies according to the magnitude, direction, and area of application of the force. The stress values turn out to be higher under the application of dysfunctional forces both in magnitude and in direction, producing significant tensile stresses for the dental and cervical periodontal structure, while under functional loads applied in any direction, no damaging stresses are generated. This supposes the recognition of the power of structural detriment of the tooth and periodontium against centric and eccentric bruxism.

Efecto del estrés agudo y de la variación del estímulo masticatorio sobre el dolor nociceptivo somático en un modelo murino

Introducción. El estrés agudo se relaciona con la enérgica liberación de catecolaminas, citoquinas y cortisol, las cuales afectan la percepción dolorosa. La masticación estimula neuronas serotoninérgicas, dichas neuronas modulan a las vías neurales del dolor; sin embargo, la relación entre dichas variables aún está en proceso de entendimiento. Objetivo. Determinar el efecto del estrés agudo y del estímulo masticatorio sobre el dolor. Métodos. Experimento que se desarrolló en el bioterio de la Facultad de Medicina de la UNMSM. 40 ratones Balb/c machos de 8 semanas de edad. Los ratones fueron asignados aleatoriamente en 5 grupos iguales. A: semana 1 sin ningún estímulo y semana 2 estimulo masticatorio + estrés. B: semana 1 sin ningún estímulo y semana 2 estrés. C: semana 1 estrés y semana 2 sin ningún estímulo. D: semana 1 estímulo masticatorio + estrés y semana 2 sin ningún estímulo. E: control, sin ningún estimulo. El dolor se evaluó en los 5 grupos a los 7 y 14 días mediante la prueba de tiempo de retirada de la cola ante estímulo térmico. Resultados. Se empleó la prueba de ANOVA para la evaluación intergrupo, no hallándose diferencia significativa. Mediante la prueba de t student para muestras relacionadas se hizo la evaluación intragrupo donde se encontró diferencia significativa entre los 7 vs los 14 días tanto en el grupo A (p=0,029) como en el grupo C (p=0,03). Conclusión. El efecto del estrés agudo sobre la percepción dolorosa fue disminuida por el estímulo masticatorio en ratones Balb/c.

Introduction. Acute stress is related to the energetic release of catecholamines, cytokines, and cortisol, which trigger pain perception. Chewing stimulates serotonergic neurons, these neurons modulate the neural pathways of pain; however, the relationship between these variables is still in the process of understanding. Objective. To determine the effect of acute stress and chewing stimulus on pain. Methods. an experiment that was developed in the Faculty of Medicine of the UNMSM. 40 eight-week-old male Balb/c mice were randomly assigned into 5 equal groups. A: week 1 without any stimulus and week 2 chewing stimulus + stress. B: week 1 without any stimulus and week 2 stress. C: week 1 stress and week 2 without any stimulus. D: week 1 masticatory stimulus + stress and week 2 without any stimulus. E: control, without any stimulus. Pain was assessed in the 5 groups at 7 and 14 days using the tail-withdrawal time test before thermal stimulation. Results. The ANOVA test was used for the intergroup evaluation, finding no significant difference. Using the t student test for related samples, the intragroup evaluation was made, where a significant difference was found between 7 vs. 14 days, both in group A (p=0.029) and in group C (p=0.03). Conclusion. The effect of acute stress on pain perception was decreased by chewing stimulus in Balb/c mice.

A dentição do idoso e as implicações alimentares / The dentition of the elderly and the food implications / La dentición de los ancianos y las implicaciones alimentarias

O envelhecimento acarreta mudanças em todos os aspectos da vida, sendo caracterizado por uma modificação nas funções sociais, mentais e corporais. No Sistema Estomatoglossognático, é possível observar alterações significativas, começando pela fase preparatória da deglutição e da função de mastigação, decorrente da perda dos dentes, a qual é responsável pela trituração do alimento, formação do bolo alimentar e perda do tônus dos músculos que são responsáveis pelos movimentos mastigatórios. Esta pesquisa observou como as alterações dentárias em idosos podem repercutir na sua alimentação. Foi realizado um estudo observacional transversal, com amostra de 33 idosos frequentadores da Igreja Evangélica Assembleia de Deus em Alagoas, no município de Coqueiro Seco. Foi feita aplicação de um instrumento de coleta, o qual possuía perguntas baseadas no MBGR e na escala EAT-10. Os resultados mostraram que há um grande número de idosos que fazem uso de prótese dentária, refletindo na execução da função mastigatória, escolha da consistência alimentar e aspectos socioemocionais. As próteses dentárias, quando bem adaptadas, podem gerar um ganho significativo ao paciente, permitindo uma alimentação que não interfere na sua postura social, nem em suas questões emocionais. (AU)

Aging causes changes in all aspects of life, being characterized by a change in social, mental and bodily functions. In the Stomatoglossognathic System, it is possible to observe significant changes, starting with the preparatory phase of swallowing and the chewing function, resulting from the loss of teeth; which is responsible for crushing food, formation of food bolus and loss of muscle tone that are responsible for masticatory movements. This research observed how dental changes in the elderly can affect their diet. A cross-sectional observational study was carried out, with a sample of 33 elderly people attending the Evangelical Assembly of God Church in Alagoas, in the municipality of Coqueiro Seco. A collection instrument was applied, which had questions based on the MBGR and the EAT-10 scale. The results showed that there is a large number of elderly people who use dental prosthesis, reflecting on the performance of masticatory function, choice of food consistency and socio-emotional aspects. Dental prostheses, when well adapted, can generate a significant gain for the patient, allowing a diet that does not interfere with their social posture, nor with their emotional issues. (AU)

El envejecimiento provoca cambios en todos los aspectos de la vida, caracterizándose por un cambio en las funciones sociales, mentales y corporales. En el Sistema Estomatoglosognático, es posible observar cambios significativos, a partir de la fase preparatoria de la deglución y de la función masticatoria, resultantes de la pérdida de dientes; que se encarga de triturar los alimentos, formación de bolos alimenticios y pérdida de tono muscular que son responsables de los movimientos masticatorios. Esta investigación observó cómo las alteraciones dentales en los adultos mayores pueden afectar su alimentación. Se realizó un estudio observacional transversal, con una muestra de 33 ancianos asistentes a la Iglesia Evangélica Asamblea de Dios de Alagoas, en el municipio de Coqueiro Seco. Se aplicó un instrumento de recolección, el cual contó con preguntas basadas en el MBGR y la escala EAT-10. Los resultados mostraron que existe un gran número de ancianos que utilizan prótesis dental, reflexionando sobre el desempeño de la función masticatoria, elección de la consistencia de los alimentos y aspectos socioemocionales. Las prótesis dentales, bien adaptadas, pueden generar una ganancia importante para el paciente, permitiendo una alimentación que no interfiere con su postura social, ni con sus problemas emocionales. (AU)

Cambios en parámetros masticatorios con prótesis parcial removible para dientes posteriores perdidos / Changes in masticatory parameters with removable partial dentures for missing posterior teeth

Introducción: el reemplazo de dientes perdidos aspira a mejorar la función masticatoria. Aunque hay diferentes opciones para ello, la conveniencia de la prótesis parcial removible (PPR) es su bajo costo. Objetivo: comparar el desempeño masticatorio (DM) después de 20 ciclos masticatorios y al umbral de la deglución (UD) en adultos de 50 a 70 años con dientes posteriores perdidos (DPP), con/sin PPR; y los ciclos hasta la deglución. Material y métodos: estudio transversal en 35 adultos con dientes anteriores y PPR bien ajustadas y utilizadas para comer. El lado de prueba fue el lado con más DPP. El DM se evaluó después de 20 ciclos y al UD utilizando un alimento prueba artificial (Optosil Comfort®) con/sin la PPR en orden aleatorizado. Las partículas se tamizaron para determinar el tamaño medio de partícula (TMP) como medida del DM. Los ciclos se contaron visualmente. Estadística descriptiva y comparaciones con SPSS-v23. Resultados: hubo diferencias significativas (p ≤ 0.05) al masticar con/sin PPR. El TMP fue más pequeño (mejor DM) con la PPR después de 20 ciclos y al UD (3.9 vs 4.4 mm y 3.2 vs 4.2 mm). Los ciclos para llegar al UD disminuyeron con la PPR (40 vs 47). Conclusión: a pesar de una mejora limitada de la función masticatoria, las PPR ayudan a preparar los alimentos en partículas más pequeñas antes de deglutirlas. La mejoría en DM con PPR es de 24% al UD, realizando menos ciclos antes de deglutir sus alimentos (AU)

Introduction: replacement of missing teeth should improve masticatory function. Although there are different options removable partial dentures (RPD) are used due to their lower cost. Objective: to compare masticatory performance (MP) after 20 chewing-cycles and swallowing-threshold (ST) in 50-70 year-old adults with missing posterior teeth (MPT) with and without their cast-metal RPD; chewing cycles until swallowing were also compared. Material and methods: 35 adults participated in this cross-sectional study. Subjects with anterior teeth and welladjusted RPDs, used for eating were included. The side with more MPT was selected as the test side. MP was evaluated after 20 cycles and ST using an artificial test-food (Optosil Comfort®) with/without the RPD (subject-own-control) (randomized order). Chewed particles were sieved to determine medium-particle-size (MPS) as a measure of MP. Chewing cycles were visually counted. Descriptive statistics and comparisons were run with SPSS v23. Results: there were significant differences (p ≤ 0.05) for all parameters when chewing with/without the RPD. MPS was smaller (better MP) with the RPD (3.9 vs 4.4 mm and 3.2 vs 4.2 mm) after 20 cycles and ST respectively. Cycles required to reach ST were less when chewing with the denture (40 vs 47). Conclusion: despite a limited improvement of masticatory function RPDs help patients prepare their food into smaller particles before swallowing. Improvement in MP with RPDs for patients with MPT is 24% at ST and they perform fewer chewing cycles before swallowing food (AU)

Application of chewing gum combined with dexmedetomidine nasal drops in intestinal preparation and rapid rehabilitation of colonoscopy / 中国实用护理杂志

Objective:To explore the application effect of chewing gum combined with dexmedetomidine nasal drops in colonoscopy intestinal preparation and rapid rehabilitation.Methods:Using the method of clinical controlled trial and convenient sampling, 126 patients who underwent painless colonoscopy in Shaoxing Second Hospital from January 2019 to December 2020 were selected as the study subjects. The patients were divided into control group and observation group with 63 cases in each group by random number table method. The control group was prepared for routine colonoscopy, and the observation group was intervened with chewing gum on the basis of the operation method of the control group. The intestinal cleanliness, the effect of removing bubbles in the intestinal tract, the time consuming of colonoscopy operation (time consuming of inserting the colonoscope and time consuming of removing the colonoscope), defecation (time consuming of first defecation after operation, time consuming of stool emptying before operation) and adverse reactions during colonoscopy were compared between the two groups.Results:Before the intervention, there was no significant difference in the general data between the two groups ( P>0.05). After intervention, the cleanliness scores of the right colon, transverse colon and left colon in the observation group were (2.12 ± 0.58) points, (2.23 ± 0.75) points and (2.18 ± 0.46) points respectively, which were higher than those of the control group (1.82 ± 0.63) points, (1.93 ± 0.72) points and (1.90 ± 0.81) points, with a statistically significant difference ( t=-2.78, -2.29, -2.39, all P<0.05). The score of the effect of removing bubbles in the intestine in the observation group was (1.12 ± 0.41) points, it was lower than that of the control group (1.87 ± 0.45) points, and the difference was statistically significant ( t=9.78, P<0.05). After intervention, the time of inserting the mirror, the time of first defecation after operation and the time of emptying stool before operation in the observation group were (5.46 ± 1.12) min, (50.36 ± 10.67) min and (141.03 ± 14.31) min respectively, which were lower than those in the control group (6.53 ± 1.25) min, (67.02 ± 11.25) min and (153.35 ± 17.32) min, and the difference was statistically significant ( t=5.06, 8.53, 4.35, all P<0.05). There was no statistically significant difference between the two groups in the time of withdrawing the mirror ( P>0.05) and adverse reactions ( t=1.49, χ2=0.00, both P>0.05). Conclusions:Chewing gum combined with dexmedetomidine nasal drip can improve the effect of intestinal preparation and promote the rehabilitation after colonoscopy without increasing the risk of adverse reactions.

Effects of chewing gum on mask contamination

Aims@#The aim of this study was to evaluate whether chewing gum affects mask contamination.@*Methodology and results@#Two groups of participants were requested to wear a mask for 15 min with (experimental group) or without (control group) chewing gum. Then, masks were collected and CFU calculation and 16S rDNA sequencing was performed. We found that temperature, humidity and bacterial CFU inside of the mask significantly increased when wearing a mask while chewing gum. Staphylococcus epidermidis was found in both groups. Staphylococcus aureus, Staphylococcus haemolyticus, Streptococcus oralis, Streptococcus parasanguinis and Bacillus wiedmannii were found in only the experimental group.@*Conclusion, significance and impact of study@#Chewing gum significantly increased the temperature, humidity and bacterial CFU inside the mask. Staphylococcus epidermidis, S. aureus, S. haemolyticus, S. oralis, S. parasanguinis and B. wiedmannii were detected inside the mask after chewing gum.

Research progress in effect of chewing-side preference on temporomandibular joint and its relationship with temporo-mandibular disorders / 浙江大学学报·医学版

Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.

The association between Betel Quid Chewing and Metabolic Syndrome among urban adults in Mandalay District of Myanmar / Journal of the ASEAN Federation of Endocrine Societies

Background@#As the prevalence of metabolic syndrome, obesity and diabetes increase worldwide, the need to identify modifiable lifestyle risk factors also increases, especially those that may be relatively unique to a specific population. To explore a possible association between betel quid chewing and metabolic syndrome, a community-based cross-sectional study was conducted.@*Methodology@#Three hundred ninety-one (391) adults were interviewed and the following parameters were measured: triglycerides, HDL-cholesterol, glucose, waist circumference, body mass index and blood pressure. Multiple logistic regression was used to determine the association between betel quid chewing and metabolic syndrome while controlling for confounders.@*Results@#The prevalence of metabolic syndrome was similar in chewers and non-chewers, 50% and 49%, respectively. After controlling for other factors, development of metabolic syndrome was positively associated with number of betel quid chewed per day, age greater than 40 years , and a positive family history of hypertension and diabetes. Regarding the duration of betel chewing, when analyzed by sex, the risk was doubled in men compared to non-chewers (OR 2.15; 95% CI = 1.21, 3.84]). As a result, a man chewing more than 10 pieces (OR 2.49; 95% CI = 1.36, 4.57]) of betel quids per day for more than 10 years had a two-fold increased chance of developing the metabolic syndrome.@*Conclusions@#Frequency and duration of betel quid chewing may represent a behavioral lifestyle target for approaches to reduce the incidence of metabolic syndrome.

Preparation of Baoyuan Chewable Tablets and Evaluation of Its Anti-fatigue Effect / 中国实验方剂学杂志

ObjectiveTo screen the preparation technology of Baoyuan chewable tablets and to preliminarily elucidate its anti-fatigue effect and mechanism. MethodTaking encapsulation rate of volatile oil， extract rate and extraction rate of active ingredients as indexes， single factor test and orthogonal test were used to optimize the volatile oil inclusion， aqueous decoction and formulation molding processes of Baoyuan chewable tablets. ICR rats were randomly divided into the blank group， model group， Gaoshan Hongjingtian oral liquids group（6.01 mL·kg-1） and and Baoyuan chewable tablets low， medium， and high dose groups（2.1， 4.2， 8.4 g·kg-1）， 8 mice in each group， and were administered by gastric gavage at the corresponding dose once a day， the blank and model groups were given equal volume of saline for 15 d. After the last administration for 30 min， the mice were loaded with 5% of the body mass of lead at the tail and swam until exhaustion to establish the fatigue model， and the weighted swimming time of the mice in each group was recorded， meanwhile， the muscle tissues of the mice were sliced， stained by hematoxylin-eosin（HE） and subjected to pathological observation， and the levels of blood urea nitrogen（BUN）， lactic acid（LA）， liver glycogen（LG）， activities of lactate dehydrogenase（LDH） and creatine kinase（CK） in the serum were determined. ResultThe optimal inclusion process of cinnamon oil in Baoyuan chewable tablets was 10∶1 for β-cyclodextrin-volatile oil， and inclusion at 50 ℃ for 2 h with saturated aqueous solution method. The optimal water extraction process was to extract twice， adding 10 times of water to extract for 50 min for the first time， and adding 9 times of water to extract for 40 min for the second time. The ratio of the extract of Baoyuan chewable tablets with microcrystalline cellulose， maltodextrin， mannitol， citric acid， magnesium stearate was 63∶13∶8∶17∶17∶1∶1， the tablets were pressed by wet granulation， the each tablet weight was 1.2 g， and the hardness was 60-80 N. Compared with the model group， Baoyuan chewable tablets low， medium， and high dose groups could significantly prolong the exhaustion time of mice in weight bearing swimming（P<0.05， P<0.01）， and improve the exercise endurance of the body， and the results of HE staining showed that all dose groups of Baoyuan chewable tablets could significantly improve the muscle tissue damage caused by exercise， significantly reduce the levels of BUN， LA and the activities of LDH and CK in serum（P<0.01）， and significantly increase the content of LG（P<0.05， P<0.01）. ConclusionThe optimized preparation process of Baoyuan chewable tablets is stable and feasible， and the preparation can improve exercise endurance by increasing the LG level in liver tissue， and relieve muscle soreness by accelerating the removal of LA from the body， and reduce CK and LDH activities to exert anti-fatigue effects.

Efecto del estrés crónico y de la masticación sobre los niveles séricos de interleuquina-6 e interferón-gama / Effect of chronic stress and chewing on serum interleukin-6 and interferon-gamma levels

Introducción: el estrés crónico afecta el equilibrio inmunológico alterando los niveles séricos de interleuquina-6 (IL-6) e interferón gama (INF-γ), dicha alteración afecta al sistema nervioso y al comportamiento humano. La masticación adecuada disminuiría dichos efectos. El objetivo del estudio fue determinar el efecto del estrés crónico y de la masticación sobre los niveles séricos de IL-6 e INF-γ. Métodos: experimento donde se emplearon 64 ratones Balb/c de 8 semanas de edad. Se dividieron en 4 tratamientos: Grupo NE: Masticación normal + estrés, Grupo N: masticación normal sin estrés, Grupo DE: Masticación deficiente + estrés, Grupo D: masticación deficiente sin estrés. Mediante test de ELISA se midió IL-6 e IFN-γ alfinal de la 4ta y de la 8va semana de tratamiento. Resultados: tanto la IL-6 como el IFN-γ fueron mayores en el grupo DE (p<0,05) al final de la 4ta semana. Al evaluarlos al término de la 8va semana se observó que en el grupo NE se incrementó la IL-6 respecto al resto de grupos (p<0,0001), y en el grupo DE fue donde se encontró mayor cantidad de IFN-γ (p<0,0001). Conclusión: el estrés crónico y la masticación deficiente incrementan los niveles séricos de IL-6 e IFN-γ. En cambio, la adecuada masticación disminuye el nivel de tales citoquinas al final de la cuarta semana de tratamiento.

Introduction: chronic stress affects the immune balance by altering the serum levels of interleukin-6 (IL-6) and gamma interferon (INF-γ), this alteration affects the nervous system and human behavior. Appropriate chewing would lessen these effects. The aim of this study was to determine the effect of chewing and chronic stress over serum levels of IL-6 and INF-γ. Methods: experiment in which 64 Balb/C mice of 8 weeks of age were used, they were divided into 4 treatments: Group NE: Normal chewing + stress, Group N: normal chewing without stress, Group DE: Chewing poor + stress, Group D: poor chewing without stress. IL-6 and IFN-γ were measured by ELISA after 4 and 8 weeks of treatment. Results: both IL-6 and IFN-γ were higher in the DE group (p < 0,05) at the end of fourth week of treatment. When evaluating the animals at the end of the eighth week of treatment, it was observed that in the NE group, the IL-6 was increased with respect to the rest (p < 0,0001) and the DE group showed more IFN-γ (p < 0,0001). Conclusion: stress and poor chewing increase serum IL-6 and IFN-γ. In contrast, appropriate chewing decreases the effects of stress on the increase of such cytokines at the end of the fourth week of treatment in animals.

Effect of chewing behavior modification on food intake, appetite and satiety-related hormones: A Systematic Review

Purpose: Obesity has become a growing public health issue worldwide. Studies have shown that eating rate is one of the most important factors to consider in the strategies to prevent and/or treat obesity. Eating rate can be reduced through different strategies, such as an increase in oro-sensory exposure, the modification of food texture, and an increase in the number of chewing cycles. The aim of this systematic review was to analyze the available evidence regarding the effect of chewing behavior modification on the parameters that contribute to obesity. Methods: A systematic search was done on the electronic databases Pubmed, Cochrane Central Register of Controlled Trials, and Scopus, using the terms "mastication", "chewing", "chewing speed", "prolonged chewing", "number of chews", "masticatory cycles" "satiety" "satiety response" "appetite", "appetite regulation", "nutritional status" and "obesity". Results: A total of 23 intervention studies were selected that intervened in the participants' chewing behavior, either by reducing the eating rate, increasing oro-sensory exposure, food hardness or the number of chewing cycles. In most studies these interventions were effective at reducing food intake, subjective appetite and improving the plasma levels of satiety-related hormones and metabolites; moreover, they reduced body mass index in the long term. Conclusion: The currently available evidence seems to indicate that modifications to chewing behavior can bring with it a myriad of benefits for the treatment of obesity.

Propósito: La obesidad se ha convertido en un problema de salud pública creciente a nivel mundial. Investigaciones han demostrado que la tasa de ingesta es uno de los factores importantes a considerar en las estrategias para prevenir o tratar la obesidad. La tasa de ingesta puede reducirse a través de diferentes estrategias; el aumento de la exposición oro-sensorial, la modificación de la textura de los alimentos y el aumento en el número de ciclos masticatorios. El objetivo de esta revisión sistemática fue analizar la evidencia disponible sobre el efecto de la modificación de la conducta masticatoria sobre los parámetros que contribuyen a la obesidad. Métodos: Se realizó una búsqueda sistemática en las bases de datos electrónicas Pubmed, Cochrane Central Register of Controlled Trials y Scopus, con los términos "mastication", "chewing", "chewing speed", "prolonged chewing", "number of chews", "masticatory cycles" "satiety" "satiety response" "appetite", "appetite regulation", "nutritional status" y "obesity". Resultados: Se seleccionaron 23 estudios que intervenían en el comportamiento masticatorio de los participantes, ya sea reduciendo de la tasa de ingesta, aumentando la exposición oro-sensorial, dureza de los alimentos y número de ciclos masticatorios. Estas intervenciones resultaron ser efectivas para reducir la ingesta de alimentos, el apetito subjetivo y mejorar los niveles plasmáticos de las hormonas y metabolitos relacionados con la saciedad, además, a largo plazo, permitieron reducciones en el índice de masa corporal. Conclusión: La evidencia disponible actualmente parece señalar que las modificaciones en el comportamiento masticatorio pueden traer consigo múltiples beneficios para el tratamiento de la obesidad.

Fatores associados ao interesse de usuários de prótese total mandibular em terapia implantossuportada e impacto da reabilitação com sobredentadura com implante único / Factors associated with the interest of users of complete mandibular dentures in implant-supported therapy and the impact of rehabilitation with single-implant overdentures

Este estudo objetivou identificar os fatores que influenciam na decisão de substituir uma prótese total convencional mandibular pelo tratamento com implantes dentários, assim como avaliar a satisfação, qualidade de vida e performance mastigatória (PM) após reabilitação com sobredentaduras com implante único (SIU) em pacientes adaptados e não-adaptados a prótese total convencional (PT) mandibular. Inicialmente, foi realizado um estudo transversal com 117 usuários de PTs bimaxilares, avaliados quanto aos desfechos relacionados à prótese (número de PTs mandibulares usadas previamente, tempo de uso e profissional que confeccionou a prótese atual, e quanto ao uso regular ou não da prótese mandibular) e aspectos centrados no paciente (período de edentulismo mandibular, altura óssea mandibular e interesse do paciente em se submeter a terapia com implantes). Do total da amostra, 78 pacientes manifestaram interesse na terapia implantossuportada, e desses apenas 22 foram selecionados e reabilitados com novas PTs bimaxilares. Após critérios de elegibilidade, foram alocados após pareamento em 2 grupos: adaptados à prótese mandibular (Grupo PTA - "adaptados à PT mandibular", n:10) e não adaptados (Grupo PTN - "não adaptados à PT mandibular", n:12). Em cada paciente, foi instalado um único implante na linha média e após o período de osseointegração as próteses mandibulares foram convertidas em sobredentaduras. O desempenho mastigatório foi avaliado pelo método das tamises, a altura óssea mandibular por medição em radiografia panorâmica, satisfação por escala quantitativa com questionário validado e o impacto da saúde oral na qualidade de vida pelo questionário OHIP-Edent-19. O teste Qui-quadrado foi utilizado para análise dos dados e as razões de prevalência ajustadas por meio da regressão multivariada de Poisson no primeiro estudo; para o segundo, a análise estatística em cada grupo e entre grupos foi baseada nos testes não-paramétricos de Wilcoxon e Mann-Whitney. O intervalo de confiança para os testes foi de 95%. A amostra foi predominantemente do sexo feminino, com 66,7% (n=78) dos participantes interessados em PT mandibular implantossuportada e com idade média de 65,68±6,38 anos. A PM não influenciou a escolha pela reabilitação com implantes. A preferência pela PT implantossuportada mandibular foi associada significativamente com maior experiência prévia com PT mandibular (p=0,021) e à insatisfação quanto à retenção (p=0,005). Após a intervenção com implante, todos os pacientes não adaptados passaram a condição de adaptados. Não houve diferença entre PTA e PTN para OHIP-Edent (p=0,276) e PM (p=0,222), a satisfação foi significativa apenas para o critério "conforto em arco inferior" (p=0,043). Para comparações pré e pós-tratamento com sobredentadura, a mediana do OHIP-Edent total diminuiu significativamente em ambos os grupos. Na comparação intragrupo, essa redução foi significativa em PTA apenas para a "limitação funcional" (p=0,026), e em PTN em quase todos os domínios, exceto "disfunção social" e "incapacidade" (p>0,05). Houve aumento estatisticamente significativo para a satisfação geral de 75,41 para 90,25 (p=0,012) em PTN e de 76,10 para 90,50 (p=0,007) em PTA. Os parâmetros "mastigação", "adaptação", "retenção" e "conforto" em arco inferior foram diferentes com significância em ambos os grupos, e "gustação", "fonação" e "dor" em arco inferior foram significativos apenas para o grupo não adaptado (p<0,05). Houve diferença significativa para PM em PTN (p=0,002) e PTA (p=0,047) ao se comparar tipo de reabilitação. Não houve correlação entre PM e OHIP antes e após a reabilitação (p>0,05). Pode-se concluir que a experiência prévia com PT mandibulares convencionais e a insatisfação com a retenção dessas, influenciam o interesse pela reabilitação com sobredentadura implantossuportada mandibular, assim como, a reabilitação com sobredentadura sobre implante único apresenta-se como alternativa aos pacientes não adaptados a PT convencional mandibular, auxiliando na aceitação do uso da prótese mandibular, assim como, comprovando efeito positivo na satisfação, qualidade de vida e performance mastigatória (AU).

This study aimed to identify the factors that influence the decision to replace a conventional mandibular complete denture by treatment with dental implants, as well as to evaluate satisfaction, quality of life and masticatory performance (MP) after rehabilitation with overdentures with a single implant in patients adapted and not adapted to conventional mandibular complete denture (CD). Initially, a cross-sectional study was carried out with 117 users of bimaxillaries CDs, who were evaluated for outcomes related to the denture (number of previous mandibular CDs, time of use and professional who made the current denture, and regarding regular use of the mandibular denture) and aspects centered patients (period of mandibular edentulism, mandibular bone height and the patient's willingness to undergo implant therapy). From the total sample, 78 patients expressed interest in implant-supported therapy, and of these, only 22 were selected and rehabilitated with new bimaxillary CDs. After eligibility criteria, they were allocated after pairing into 2 groups: adapted to mandibular prosthesis (PTA Group - "adapted to mandibular CD", n:10) and non-adapted (PTN Group - " not adapted to mandibular CD", n:12). In each patient, a single implant was installed in the midline and after the osseointegration period, the mandibular prostheses were converted into overdentures. Masticatory performance was evaluated by the sieve method, mandibular bone height by paranoid radiographic measurement, satisfaction by quantitative scale with a validated questionnaire and the impact of oral health on quality of life by the OHIP-Edent-19 questionnaire. The chi-square test was used for data analysis and the prevalence ratios adjusted by means of multivariate Poisson regression in the first study; on the second, the statistical analysis in each group and between groups was based on the non-parametric-Wilcoxon and Mann-Whitney tests. The confidence interval for the tests was 95%. The sample was composed predominantly by women, with 66.7% (n=78) of the participants interested in implantsupported mandibular CD, with mean age 65.68±6.38 years. MP was not influenced by the choice by dental implants rehabilitation. Preference for mandibular implant-supported CD was significantly associated with longer previous experience in mandibular CD (p=0.021) and with dissatisfaction regarding retention (p=0.005). After the implant intervention, all non-adapted patients became adapted. There was no difference between PTA and PTN for OHIP-Edent (p=0.276) and MP (p=0.222), satisfaction was significant only for the criteria "comfort in the lower arch" (p=0.043). For pre- and post-treatment comparisons with overdentures, the median total OHIP-Edent decreased significantly in both groups. In the intragroup comparison, this reduction was significant in PTA only for "functional limitation" (p=0.026), and in PTN in almost all domains, except "social dysfunction" and "disability" (p>0.05). There was a statistically significant increase in overall satisfaction from 75.41 to 90.25 (p=0.012) in PTN and from 76.10 to 90.50 (p=0.007) in PTA. The parameters "chewing", "adaptation", "retention" and "comfort" in the lower arch were significantly different in both groups, and "gustation", "phonation" and "pain" in the lower arch were significant only for the group not adapted (p<0.05). There was a significant difference for MP in PTN (p=0.002) and PTA (p=0.047) when comparing the type of rehabilitation. There was no correlation between MP and OHIP before and after rehabilitation (p>0.05). It can be concluded that the previous experience with conventional mandibular CD and the dissatisfaction with the retention of these, influence the rehabilitation with mandibular implant-supported overdenture, as well as the rehabilitation with overdenture on single implant presents itself as an alternative for patients not adapted to mandibular conventional CD, helping to accept the use of mandibular prosthesis, as well as proving a positive effect on satisfaction, quality of life and masticatory performance (AU).

El odontólogo, custodio de la función masticatoria / The dentist, guardian of masticatory function

La masticación tiene como objetivo la adecuada preparación de los alimentos para su deglución y digestión. Cualquier alteración en el sistema estomatognático puede deteriorar la masticación. El odontó- logo es el profesional responsable de mantener y/o restaurar la función masticatoria. La evaluación de la función masticatoria puede hacerse de forma subjetiva utilizando cuestionarios para medir la percepción del paciente sobre su capacidad masticatoria o de forma objetiva analizando la fuerza oclusal, la actividad electromiográfica de los músculos mas- ticadores, la trayectoria de la mandíbula al masticar o la capacidad de trituración de los alimentos. Estos métodos se utilizan en proyectos de investigación, pero en la clínica ¿evaluamos si existe alguna alteración al masticar y al finalizar el tratamiento si cumplimos con el objetivo de restaurar la función masticatoria? ¿Realmente nos preocupamos por mantener y/o restaurar la función masticatoria? Por lo general no, ni en los consultorios, ni en las clínicas universitarias. Es esencial que nos concienticemos de nuestra responsabilidad y para ello es necesario que se le dé mayor peso curricular a la función masticatoria y cómo evaluarla. Seamos realmente custodios de la función masticatoria de nuestros pacientes (AU)

The goal of chewing is to properly prepare food for swallowing and digestion. Any problem in the stomatognathic system can deteriorate chewing. The professional responsible of maintaining and/or restoring masticatory function is the dentist. Masticatory function can be evaluated subjectively through questionnaires to measure the patient's perception of his/her masticatory capacity or objectively analyzing occlusal force, the electromyographic activity of the masticatory muscles, the movements of the mandible during chewing or the individual's capacity to breakdown food. These methods are used in research projects but, do we examine if there is any problem during chewing and if we are achieving our goal of restoring masticatory function at the end of the treatment in our offices? Do we really focus on maintaining and/or restoring masticatory function? Not truly, not in our offices or university clinics. It is imperative that we acknowledge our responsibility but for that it is essential that masticatory function and how to evaluate it is given more weight in the curriculum. Let us be genuine guardians of the masticatory function of our patients (AU)

Função mastigatória nos diferentes ciclos de vida: análise eletromiográfica / Chewing function in different life cycles: analysis with electromyography / Función masticatoria en diferentes ciclos de vida: análisis con electromiografía

Introdução: A mastigação tem uma importância significativa para o desenvolvimento das estruturas do Sistema Estomatognático (SE), sendo esta aperfeiçoada no decorrer da vida. A eletromiografia de superfície destaca-se como uma importante ferramenta de avaliação capaz de quantificar a atividade elétrica dos músculos mastigatórios, sendo uma forma de caracterizar o comportamento dessa função estomatognática. Observando a complexidade e importância da mastigação, torna-se importante conhecer melhor as modificações desta função no decorrer dos ciclos de vida. Objetivo: O objetivo do estudo foi realizar análise eletromiográfica dos músculos da mastigação em indivíduos sem queixas orofaciais representantes dos ciclos da infância, adolescência, fase adulta e senescência. Método: A amostra foi composta por 120 voluntários de ambos os sexos, distribuídos em quatro grupos de acordo com a faixa de idade. Os voluntários foram submetidos à avaliação da mastigação por meio da eletromiografia de superfície durante o repouso, contração voluntária máxima, mastigações unilaterais direita e esquerda e mastigação habitual; bem como a verificação da força de mordida entre os dentes incisivos centrais, molares do lado direito e molares do lado esquerdo. Realizou-se, ainda, a tomada de medidas antropométricas faciais das hemifaces direta e esquerda dos voluntários. Resultados: Os resultados apontaram comportamentos morfológicos e funcionais distintos entre os grupos estudados, bem como a influência da variável sexo nas respostas eletrofisiológicas da função mastigatória. Conclusão: foi verificado que o comportamento mastigatório variou segundo a idade e o sexo, apontando uma tendência de correlação entre os componetes anatômicos e funcionais envolvidos nessa função estomatognática.

Introduction: Chewing is of significant importance for the development of the structures of the Stomatognathic System (SE), which is improved throughout life. Surface electromyography stands out as an important assessment tool capable of quantifying the electrical activity of the masticatory muscles, being a way to characterize the behavior of this stomatognathic function. Observing the complexity and importance of chewing, it is important to better understand the changes in this function during the life cycles. Objective: The objective of the study was to perform an electromyographic analysis of the muscles of mastication in individuals without orofacial complaints representing the cycles of childhood, adolescence, adulthood and senescence. Method: The sample consisted of 120 volunteers of both sexes, distributed in four groups according to the age group. The volunteers underwent chewing assessment by means of surface electromyography during rest, maximum voluntary contraction, unilateral right and left chewing and habitual chewing; as well as the verification of the bite force between the central incisor teeth, molars on the right side and molars on the left side. Facial anthropometric measurements of the direct and left hemifaces of the volunteers were also taken. Results: The results showed distinct morphological and functional behaviors between the groups studied, as well as the influence of the gender variable on the electrophysiological responses of the masticatory function. Conclusion: it was found that the masticatory behavior varied according to age and sex, pointing to a trend of correlation between the anatomical and functional components involved in this stomatognathic function.

Introducción: La masticación es de gran importancia para el desarrollo de las estructuras del Sistema Estomatognático (SE), que se mejora a lo largo de la vida. La electromiografía de superficie se destaca como una importante herramienta de evaluación capaz de cuantificar la actividad eléctrica de los músculos masticatorios, siendo una forma de caracterizar el comportamiento de esta función estomatognática. Observando la complejidad de esta función, es importante conocer mejor los cambios de esta función durante los ciclos de vida. Objetivo: El objetivo del estudio fue realizar un análisis electromiográfico de los músculos de la masticación en individuos sin quejas orofaciales representando los ciclos de niñez, adolescencia, adultez y senescencia. Método: La muestra estuvo formada por 120 voluntarios de ambos sexos, distribuidos en cuatro grupos según el grupo de edad. Los voluntarios fueron sometidos a valoración masticatoria mediante electromiografía de superficie en reposo, máxima contracción voluntaria, masticación unilateral derecha e izquierda y masticación habitual; así como la verificación de la fuerza de mordida entre los incisivos centrales, molares del lado derecho y molares del lado izquierdo. También se tomaron medidas antropométricas faciales de los hemifaces directo e izquierdo de los voluntarios. Resultados: Los resultados mostraron distintos comportamientos morfológicos y funcionales entre los grupos estudiados, así como la influencia de la variable género en las respuestas electrofisiológicas de la función masticatoria. Conclusión: se encontró que el comportamiento masticatorio varió según la edad y el sexo, apuntando a una tendencia de correlación entre los componentes anatómicos y funcionales involucrados en esta función estomatognática.

Effect of treatment dentures on denture space in edentulous patients and its clinical evaluation / 口腔疾病防治

Objective@#To investigate the effect of treatment dentures on changes in denture space in edentulous patients and to evaluate its clinical effect.@* Methods@#Twenty patients with treatment dentures were investigated with a questionnaire and Oral Health Impact Profile (OHIP-14) before and after treatment. The denture space, denture tissue surface, occlusal points, Gothic arch images, mucosal condition, lateral occlusal condition, bite force, retention and stability, patient mastication ability, denture satisfaction, and OHIP-14 score were collected for statistical analysis.@*Results @# After wearing treatment dentures, the denture space significantly improved, the tissue conditioners on the treatment denture gradually began to be distributed, and the occlusal points gradually became symmetrical. The gothic arch images showed that the joints, nerves, and muscles gradually stabilized. The mucosal condition changed to a healthy state. The lateral occlusal conditions were improved. There were also significant differences in the bite force, retention and stability, subjective and objective chewing ability, satisfaction with the denture and OHIP-14 score before and after treatment (P < 0.05). The objective chewing ability was positively correlated with the retention stability of the denture, the subjective chewing ability and the satisfaction of the denture, and it was negatively correlated with OHIP-14.@* Conclusion@#Treatment dentures could help to restore denture space to an ideal condition and improve the oral health of patients. This treatment could also improve the retention and stability of the denture and the chewing ability to improve patient satisfaction. This treatment has clinical application value and promotion potential.

Effectiveness of Chewing Gum Containing CPP-ACP for Remineralisation of Demineralised Enamel around Orthodontic Brackets: An in Situ Study

Abstract Objective: To evaluate the effectiveness of chewing gums containing CPP-ACP in remineralisation of demineralised enamel around orthodontic brackets. Material and Methods: Enamel blocks from 120 bovine incisors were used. The blocks were flattened and polished, followed by the development of incipient subsurface caries. The blocks have been subjected to a baseline microhardness analysis. Orthodontic brackets were bonded to the exposed area of the blocks, reserving an area for hardness analysis. An in situ crossover (three-way crossover phases of 21 days with an interval of one week between them), controlled, randomised and blind experimental model was used, with the participation of 12 volunteers divided into groups: G1 - negative control group, without chewing gum; G2 - conventional sugar-free chewing gum, without CPP-ACP (placebo); and G3 - sugar-free chewing gum with CPP-ACP. The following parameters were analysed: superficial linear (Ra), volumetric roughness (Sa), and superficial structural loss, which was indicated by Gap measurement (difference between the healthy and treated area). Statistical tests used were the Friedman, Wilcoxon and Shapiro-Wilk, Kruskal Wallis' nonparametric tests and ANOVA. Results: There was a significant reduction in enamel microhardness after demineralisation in all the groups (p<0.05). This deleterious effect was attenuated in the three groups after the final evaluation, although there were no statistical differences (p<0.05); however, the final values did not return to the baseline values (p<0.05). Conclusion: Chewing gum containing CPP-ACP did not promote in situ remineralisation of demineralised enamel around orthodontic brackets.

Feeding behavior of lambs fed diets containing old man saltbush hay / Comportamiento ingestivo de corderos alimentados con dietas conteniendo heno de hierba-sal / Comportamento ingestivo de cordeiros alimentados com dietas contendo feno de erva-sal

Abstract Background: We hypothesized that a diet with old man saltbush hay used as an alternative source of nutrients could partially replace the concentrate in the feeding of feedlot lambs. Objective: This study evaluated the behavior and performance of lambs fed diets containing increasing levels of old man saltbush hay plus concentrate. Methods: Twenty-four castrated Santa Inês lambs at approximately eight months of age (22 ± 1.97 kg) were confined in a randomized complete design and fed diets containing 30, 40, 50, and 60% (dry matter: DM) of old man saltbush hay. Results: The intake of DM and neutral detergent fiber was not affected (p>0.05) by the level of old man saltbush hay. Intake of mineral salt decreased (p<0.01) as the proportion of old man saltbush in the diet increased. Weight gain (kg) and feed efficiency worsened (p<0.05) with 40% inclusion of old man salt bush hay. The time spent on feeding and chewing increased (p<0.05), while idle time was reduced (p<0.01) with dietary inclusion of old man saltbush. Feed efficiency decreased (p<0.05) with the inclusion of old man saltbush. Conclusion: Dietary inclusion of old man saltbush affects the feeding behavior and performance of lambs in feedlot.

Resumen Antecedentes: Nuestra hipótesis consistió en que una dieta con heno de hierba-sal como fuente alternativa de nutrientes puede sustituir parcialmente el concentrado en la alimentación de corderos confinados. Objetivo: Evaluar el comportamiento ingestivo de corderos alimentados con dietas conteniendo niveles incrementales de heno de hierba-sal asociado al concentrado. Métodos: Veinticuatro corderos Santa Inés, castrados, con aproximadamente ocho meses de edad, peso corporal de 22 ± 1,97 kg, confinados, fueron distribuidos en un arreglo experimental completamente aleatorizado y alimentados con dietas conteniendo 30, 40, 50 y 60% (materia seca: MS) de heno de hierba-sal. Resultados: El consumo de MS y fibra detergente neutra no se vió afectado (p>0,05) por los diferentes niveles de inclusión de hierba-sal. La ingestión de sal mineral se redujo (p<0,01) al incrementar la hierba-sal en la dieta. La ganancia de peso (kg) y la eficiencia alimenticia empeoraron (p<0,05) con la inclusión de 40% de heno de hierba-sal. El tiempo empleado para las actividades de alimentación y masticación aumentó (p<0,05), mientras que el de ocio se redujo (p<0,01) con la inclusión de hierba-sal. La eficiencia alimenticia de la materia seca disminuyó (p<0,05) a medida que aumentó el nivel de inclusión de heno de hierba-sal. Conclusión: La inclusión de heno de hierba-sal en la dieta afecta el comportamiento ingestivo y el rendimiento de corderos confinados.

Resumo Antecedentes: A hipótese foi que uma dieta com o feno de erva-sal como fonte alternativa de nutrientes poderia substituir parcialmente o concentrado na alimentação de cordeiros confinados. Objetivo: Este estudo foi desenvolvido para avaliar o comportamento ingestivo de cordeiros alimentados com dietas contendo feno de erva-sal associado com o concentrado. Métodos: Vinte e quatro cordeiros Santa Inês, castrados, com aproximadamente oito meses de idade, peso corporal de 22 ± 1,97 kg, confinados, foram distribuídos em um delineamento experimental inteiramente casualizado e alimentados com dietas contendo 30, 40, 50 e 60% (matéria seca (MS)) de feno de erva-sal. Resultados: O consumo de matéria seca e fibra em detergente neutro não foram comprometidos (p>0,05) pelos diferentes níveis de erva-sal. A ingestão de sal mineral reduziu (p<0,01) com o aumento de erva sal nas dietas. O ganho de peso e a eficiência alimentar pioraram (p<0,05) a partir da inclusão de 40% de feno de erva-sal na dieta dos cordeiros. O tempo despendido para as atividades de alimentação e mastigação aumentaram (p<0,05), enquanto que o de ócio reduziu (p<0,01) com a inclusão da erva sal nas dietas. A eficiência de alimentação da matéria seca diminuiu (p<0,05) à medida que se incluiu o feno de erva-sal. Conclusão: A inclusão de feno de erva-sal na dieta afeta o comportamento ingestivo eo desempenho de cordeiros confinados.

Characteristics of Chewing: An Update of the Literature

ABSTRACT: Chewing is the first step in the digestion process in mammals. It is a highly coordinated process with a complex sensorimotor activity, the aim of which is to prepare foods for the formation of the alimentary bolus and then swallowing. It is a process with defined stages and patterns of movement that adapt to changes derived from the environment or the individual. Here, we review the main characteristics of chewing, including aspects of the physiology and characteristics of the mechanics of mandibular movement. We highlight the latest advances reported and the new methodologies used for a chewing analysis, which has made it possible to collect more precise and reliable data. Thus, we will see how the new technologies have provided a better understanding of this function and its relation to aspects of an individual's general healt h such as nutrition or the appearance of neurodegenerative diseases. Also, in this review we emphasize the close relation that exists between chewing and a person's quality of life.

RESUMEN: La masticación es el primer paso en el proceso de digestión en los mamíferos, es un proceso altamente coordinado y con una compleja actividad sensoriomotora, cuyo objetivo es preparar los alimentos para la formación del bolo alimenticio y luego la deglución, es un proceso con etapas definidas y patrones de movimiento que se adaptan a los cambios derivados del entorno o del individuo, aquí se revisan las principales características de la masticación, incluyendo aspectos de la fisiología y características de la mecánica del movimiento mandibular, se destacan los últimos avances reportados y las nuevas metodologías utilizado para un análisis de la masticación, lo que ha permitido recolectar datos más precisos y confiables, así, veremos cómo las nuevas tecnologías han permitido comprender mejor esta función y su relación con aspectos de la salud general de un individuo como la nutrición o la aparición de enfermedades neurodegenerativas; además, en esta revisión destacamos la estrecha relación que existe entre la masticación y la calidad de vida.

Análise da mastigação e deglutição na paralisia cerebral com deficiência visual: estudo de caso / Analysis of chewing and swallowing in cerebral palsy with a visual impairment: study of case / Análisis de la masticación y la deglución en la parálisis cerebral con discapacidad visual: un estudio de caso

Introdução: A Paralisia Cerebral pode acarretar alterações em qualquer uma das fases da deglutição, causando uma disfagia neurogênica. No entanto, desordem neurológica e deficiência visual associada é um tema pouco estudado. A criança com a ausência do canal visual, geralmente tem pouca noção na estrutura do espaço e até mesmo em relação à sua estrutura corporal e organizacional. É sabido que a Paralisia Cerebral discorre atrasos no padrão mastigatório e da deglutição, mas questiona-se se a deficiência visual pode interferir ou não neste desempenho. Objetivo: O propósito deste estudo foi analisar as funções de mastigação e o tempo de deglutição em criança com paralisia cerebral e deficiência visual associada. Método: Esta pesquisa é de natureza exploratória e descritiva, desenvolvida por meio de um estudo de caso clínico de uma criança com paralisia cerebral e deficiência visual associada. Três consistências de alimento foram examinadas: líquido (suco), pastosa (iogurte) e sólido (pão), sendo cronometrado o tempo gasto para deglutir cada uma delas, durante o horário normal de alimentação. Resultados: os resultados mostraram que a criança com Paralisia Cerebral e Deficiência Visual apresenta dificuldades na função de mastigação e leva mais tempo para deglutir nas consistências sólida e líquida. Conclusão: A deficiência visual associada à paralisia cerebral pode acentuar na dificuldade das funções de mastigação e deglutição.

Introduction: Cerebral Palsy can cause changes in any of the phases of swallowing, causing neurogenic dysphagia. However, neurological disorder and associated visual impairment is a poorly studied topic. The child with the absence of the visual channel, generally has little idea of the structure of the space and even of its body and organizational structure. It is known that Cerebral Palsy has delays in chewing and swallowing patterns, but it is questioned whether visual impairment can interfere or not in this performance. Objective: The purpose of this study was to analyze chewing functions and swallowing time in children with cerebral palsy and associated visual impairment. Method: This research is exploratory and descriptive in nature, developed through a clinical case study of a child with cerebral palsy and associated visual impairment. Three food consistencies were examined: liquid (juice), pasty (yogurt) and solid (bread), with the time spent swallowing each of them during the normal feeding time being timed. Results: the results showed that the child with Cerebral Palsy and Visually Impaired presents difficulties in chewing function and takes more time to swallow in solid and liquid consistencies. Conclusion: Visual impairment associated with cerebral palsy may accentuate the difficulty in chewing and swallowing functions.

Introducción: La parálisis cerebral puede provocar cambios en cualquiera de las fases de la deglución, provocando disfagia neurogénica. Sin embargo, el trastorno neurológico y la discapacidad visual asociada es un tema poco estudiado. El niño con ausencia del canal visual, generalmente tiene poca idea de la estructura del espacio e incluso de su cuerpo y estructura organizativa. Se sabe que la parálisis cerebral tiene retrasos en los patrones de masticación y deglución, pero se cuestiona si la discapacidad visual puede interferir o no en este desempeño. Objetivo: El propósito de este estudio fue analizar las funciones de masticación y el tiempo de deglución en niños con parálisis cerebral y discapacidad visual asociada. Método: Esta investigación es de naturaleza exploratoria y descriptiva, desarrollada a través de un estudio de caso clínico de un niño con parálisis cerebral y discapacidad visual asociada. Se examinaron tres consistencias de alimentos: líquido (jugo), pastoso (yogur) y sólido (pan), y se pasó el tiempo de deglución de cada uno de ellos durante el tiempo normal de alimentación. Resultados: los resultados mostraron que el niño con parálisis cerebral y deficiencia visual tiene dificultades en la función de masticación y toma más tiempo para tragar en forma sólida y líquida. Conclusión: la discapacidad visual asociada con la parálisis cerebral puede acentuar la dificultad en las funciones de masticación y deglución.

Investigação do potencial erosivo de gomas de mascar não convencionais / Investigation the erosive potential of unconventional chewing gums

Objetivo: mensurar o potencial erosivo de gomas de mascar não convencionais disponíveis no mercado brasileiro. Material e método: estudo experimental (in vitro) de caráter quantitativo. Foram adquiridos oito sabores de gomas de mascar: Poosh® (pinta língua); Plutonita® (abraço congelante, dentada ardente, baba de bruxa e língua ácida); e TNT® (sangue, lava e tumba). Para análise da acidez, foram realizadas leituras em triplicata do pH e acidez titulável (AT), utilizando um potenciômetro e eletrodo combinado de vidro em soluções obtidas após a maceração das gomas de mascar em água duplamente deionizada. Nas soluções com valores de pH inferiores a 5,5, foi mensurada a AT adicionando-se alíquotas de 100 µLNaOH 0,1 M, até alcançar pH 5,5. Os resultados foram submetidos à Análise de Variância (ANOVA). As comparações das médias de pH e acidez titulável foram realizadas pelo teste de Tukey, com um nível de 5% de significância (p<0,05). Resultados: os valores de pH variaram entre 2,4 (abraço congelante) e 3,5 (baba de bruxa), diferin-do significantemente do controle (água mineral/pH=6,2). Os valores de acidez titulável variaram entre 628µL de NaOH 0,1 M (sangue) e 10700µL de NaOH 0,1 M (abraço congelante). A goma de mascar sabor abraço congelante apresentou o pH mais baixo e a mais elevada acidez titulável, diferindo significantemente dos demais sabores. Conclusões: as gomas de mascar avaliadas são ácidas, mas diferem quanto ao seu potencial erosivo. Seu consumo abusivo pode constituir um fator de risco para erosão dental.(AU)

Objective: to measure the erosive potential of non- -conventional chewing gums available in the Brazilian market. Material and methods: this is an in vitro study using the following flavors of chewing gums from the Brazilian market: Poosh® (tongue cleaner); Plutonita® (freezing hug, burning bite, witch slime and acid tongue); TNT® (blood, lava and tomb). For acidity analysis, pH and titratable acidity (TA) readings were performed in triplicate using a potentiometer and combined glass electrode in solutions obtained after maceration of the chewing gums in double deionized water. In solutions with pH values below 5.5, the TA was measured by adding aliquots of 100 µL 0.1 M NaOH, until pH 5.5 was reached. The results were submitted to Analysis of Variance (ANOVA). Comparisons of pH and titratable acidity means were performed by Tukey test at a 5% significance level (p<0.05). Results: the pH values that ranged from 2.4 (freezing hug) to 3.5 (witch's slime) differed significantly from the control (mineral water/ pH=6.2). Titratable acidity values ranged from 628µL of 0.1 M NaOH (blood) to 10700µL of 0.1 M NaOH (freezing hug). The freezing hug flavor chewing gum had the lowest pH and the highest titratable acidity differing significantly from the other flavors. Conclusions: the evaluated chewing gums are acidic, but differ in their erosive potential. Their abusive consumption may constitute a risk factor for dental erosion.(AU)