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Journal of Dairy Science Jun 2023Historical research had shown that forage particle size influences chewing activity, ruminal pH, volatile fatty acid profiles, and milk fat percentage. With this in... (Review)
Review
Historical research had shown that forage particle size influences chewing activity, ruminal pH, volatile fatty acid profiles, and milk fat percentage. With this in mind, Mertens in 1997 published one of the most frequently cited papers in the Journal of Dairy Science that laid out a comprehensive system for integrating neutral detergent fiber (NDF) and particle size of feeds into one measure: physically effective NDF (peNDF). Based on total chewing time (i.e., eating plus ruminating), peNDF enabled ration formulation to meet the minimum fiber requirements of ruminants to maintain ruminal pH and milk fat. Total chewing time is related to feed NDF content and particle size, so Mertens proposed that peNDF could be determined simply from a chemical measure of NDF and particle size measured as the fraction of dry matter retained on a 1.18-mm sieve with vertical shaking of a dried sample. In the past 2 decades, the peNDF system has been incorporated into nutrition models and is routinely used in ration formulation. Early on, Mertens recognized that starch would affect the minimum peNDF requirements, and his work was the first to demonstrate that starch and fermentation pH affect ruminal fiber degradation kinetics. Subsequently, Mertens's insight into particle size analysis was extended from fibrous feeds to corn silage processing with the development of the commonly used corn silage fragmentation index for assessing starch availability. Participants at the 33rd Discover Conference on fiber in 2017 ranked improved physical description of feeds as a top priority for future research, undoubtedly recognizing the need to carry forward Mertens's pioneering work. Future research will likely focus on improving the physicochemical and biological evaluation of rumen fiber degradation and passage, thereby improving the prediction of animal response. The comprehensive system that David Mertens built for meeting the fiber requirements of ruminants has transformed ration formulation.
Topics: Female; Animals; Lactation; Diet; Digestion; Dietary Fiber; Silage; Mastication; Starch; Fermentation; Particle Size; Rumen
PubMed: 36400612
DOI: 10.3168/jds.2022-22419 -
Clinical and Experimental Dental... Feb 2023Chewing increases frontal lobe activity, resulting in improved memory, learning ability, and response reaction time. This study aimed to assess the effects of elastic...
OBJECTIVES
Chewing increases frontal lobe activity, resulting in improved memory, learning ability, and response reaction time. This study aimed to assess the effects of elastic oral appliance chewing on the activities and functions of the frontal lobe.
METHODS
The study participants were 15 healthy men with full dentulous (mean age, 27.4 ± 4.1 years). A prospective crossover design was used to assess frontal lobe activities and functions. Changes in frontal lobe activities were measured with near-infrared spectroscopy (NIRS). At baseline, the participants were assessed in the resting state. Changes in channels #7, representing right frontal lobe activities by NIRS, and #10, representing left frontal lobe activities, during the first and second chewing periods in a total of two periods were evaluated. Frontal lobe functions were measured using the Trail Making Test Part A (TMT-A) in the resting state and after elastic oral appliance or gum chewing. These values were compared with each period.
RESULTS
Elastic oral appliance chewing caused significant differences between the baseline and first chewing periods for channel #7 (p = .032) and significant differences between the baseline and second chewing periods for channels #7 and #10 (p < .001 and p < .001, respectively) using NIRS. Moreover, significant differences were found in the TMT-A results between the resting state and elastic oral appliance chewing (p = .04).
CONCLUSIONS
Elastic oral appliance chewing improves frontal lobe activities to a level similar to that obtained with gum chewing.
Topics: Adult; Humans; Male; Young Adult; Chewing Gum; Frontal Lobe; Learning; Mastication; Prospective Studies; Cross-Over Studies
PubMed: 36625848
DOI: 10.1002/cre2.710 -
International Journal of Language &... Jan 2023Quantitative measures can increase precision in describing swallowing function, improve interrater and test-retest reliability, and advance clinical decision-making. The...
BACKGROUND
Quantitative measures can increase precision in describing swallowing function, improve interrater and test-retest reliability, and advance clinical decision-making. The Test of Mastication and Swallowing Solids (TOMASS) and the Timed Water Swallow Test (TWST) are functional tests for swallowing that provide quantitative results.
AIMS
To explore the relationship between TOMASS and TWST; evaluate test-retest and interrater reliability; explore age and gender effects; and gather normative data.
METHODS & PROCEDURES
Healthy community dwelling participants (n = 298, ≥ 20 years old) were recruited. Of those, 126 were included in the reliability study. Participants completed the TWST and TOMASS.
OUTCOMES & RESULTS
Associations between TWST and TOMASS measures were found using Pearson's correlation coefficient. Age was positively associated with an increase in the number of bites (n = 292, r = 0.15, p = 0.009), masticatory cycles (n = 291, r = 0.33, p < 0.0001) and duration (n = 292, r = 0.32, p < 0.0001) for the TOMASS. For the TWST, age was positively associated with an increase in duration (n = 296, r = 0.23, p < 0.0001), and negatively associated with volume (n = 296, r = -0.205, p < 0.0001), and swallowing capacity (n = 296, r = -0.24, p < 0.0001). Females required more bites, masticatory cycles, swallows and longer time than males in TOMASS. In TWST, females required more swallows, longer time, and had lower volume per swallow and reduced swallowing capacity than males. Intraclass correlation coefficient (ICC) revealed good test-retest reliability and moderate to excellent interrater reliability.
CONCLUSIONS & IMPLICATIONS
This study provides support for the validity of the TOMASS and TWST. Reduced efficiency in one of the tests might indicate a need to evaluate performance in the other. Extended chewing time and increased number of masticatory cycles might be compensatory behaviours for reduced oral processing abilities that are motor, sensory and/or mechanical.
WHAT THIS PAPER ADDS
The TOMASS and TWST are functional tests of swallowing that provide quantitative results. They are easy to incorporate as part of the clinical evaluation of swallowing due to low cost and quick administration. Age and gender effects were found for the TWST and TOMASS, but they were only tested on relative measures rather than absolute measures. Different types of crackers used for TOMASS led to differences in performance and in normative values. What is already known on the subject Associations between performance during TWST and TOMASS were found: time, number of swallows and time per swallow were correlated, meaning that need for more time and more swallows is reflected in both drinking and chewing. The study provides further support for age and gender effects in TWST and TOMASS, on both relative and also on absolute measures, which were not investigated previously. Longer durations in TOMASS and TWST with an increase in age, are likely to be the result of compensatory behaviours to allow safe swallowing. Normative data for a country-specific cracker are presented (Israel). What are the potential or actual clinical implications of this work? Reduced efficiency in one of the tests might indicate a need to evaluate performance in the other. Establishing country specific norms for commonly available crackers is necessary, since crackers size and ingredients, such as fat content and moisture, influence chewing and swallowing. There is a balancing act between safety and efficiency in older adults' swallowing behaviour. Reducing pace in eating and drinking probably supports safer swallowing.
Topics: Male; Female; Humans; Aged; Young Adult; Adult; Deglutition; Mastication; Reproducibility of Results; Deglutition Disorders; Time Factors
PubMed: 36036753
DOI: 10.1111/1460-6984.12768 -
Maternal & Child Nutrition Jan 2019Previous research demonstrated that faster eating rates are linked with increased intake of energy during a meal. Here, we examined whether within-meal parental feeding...
Previous research demonstrated that faster eating rates are linked with increased intake of energy during a meal. Here, we examined whether within-meal parental feeding practices show cross-sectional and prospective associations with children's oral processing behaviours and whether the previously demonstrated association between faster eating rates and higher energy intakes varies by parental feeding practices. A subset (n = 155) of children and their mothers from the Growing Up in Singapore Towards healthy Outcomes cohort participated in an ad libitum meal at age 4.5 years. Children's oral processing behaviours (eating rate, bite size, chews per gram, oral exposure time, and meal duration) and parental feeding practices (autonomy-supporting and coercive prompts, restrictions, hurrying, and slowing) were recorded during the meal. Subsequently, 94 of the children participated in a follow-up meal without their mothers at age 6 years. Parental feeding practices were not consistently associated with child oral processing behaviours overall. However, exploratory post hoc analyses revealed some sex differences. The mothers of girls with faster eating rates, larger bite sizes, and fewer chews were more likely to use hurrying, slowing, and restrictions, but similar associations were not observed among boys. Children who had the most problematic eating style and were eating fast and for long experienced more restrictions, instructions to slow down, and prompts. Faster eating rates were linked with the highest energy intakes if children were additionally prompted to eat. Prospective analyses showed that children who were more often prompted using coercive techniques and less frequently hurried at age 4.5 years had faster eating rates at 6 years and a larger increase in eating rates between ages 4.5 and 6 years but did not consume more energy. Although the direction of these associations cannot be assumed, these exploratory analyses suggest sex differences in the associations between feeding practices and oral processing behaviours and highlight the potential role of parents in the development of children's oral processing behaviours.
Topics: Child; Child Behavior; Child, Preschool; Cross-Sectional Studies; Energy Intake; Feeding Behavior; Female; Humans; Male; Mastication; Parents; Prospective Studies; Singapore
PubMed: 30051652
DOI: 10.1111/mcn.12635 -
CoDAS 2021To characterize the masticatory function of the elderly and to compare total amount of time, masticatory strokes and total mastication score among the elderly and young... (Observational Study)
Observational Study
PURPOSE
To characterize the masticatory function of the elderly and to compare total amount of time, masticatory strokes and total mastication score among the elderly and young adults.
METHODS
It is an observational, cross-sectional and analytical study. A total of 50 individuals participated, 25 elderly (mean age 66 years) and 25 young adults (mean age 22 years). The evaluation of mastication was performed by standardized filming of the usual mastication of a wheat flour biscuit. The masticatory type (alternated bilateral, simultaneous bilateral, preferential unilateral, chronic and anterior), masticatory score, total masticatory time and the total number of masticatory strokes were verified and compared between the elderly and young adults.
RESULTS
The predominant masticatory pattern in the young adults was the alternated bilateral mastication (52%), while, in the elderly, the simultaneous bilateral mastication predominated (48%). The use of dental prostheses had a significant influence on the total mastication score; elderly presented greater masticatory time and greater amount of masticatory strokes; however, the total masticatory score was lower for this group.
CONCLUSION
The use of dental prosthesis has a significant influence on masticatory function. When compared to young adults, the elderly had a greater amount of time and masticatory strokes and a lower total mastication score.
Topics: Adult; Aged; Cross-Sectional Studies; Flour; Humans; Mastication; Triticum; Young Adult
PubMed: 34705926
DOI: 10.1590/2317-1782/20212020364 -
Archives of Oral Biology Dec 2014This study assessed the degree of relationship between masticatory laterality and lateral asymmetry of masticatory performance using silicon pieces enclosed in a latex...
OBJECTIVE
This study assessed the degree of relationship between masticatory laterality and lateral asymmetry of masticatory performance using silicon pieces enclosed in a latex bag.
DESIGN
Forty-two young adults with natural dentition participated in this cross-sectional, observational study. They performed four different masticatory assays, each consisting of five trials of chewing three pieces of silicon for 20 cycles. In one assay, they were asked to masticate unbagged silicon free-style, whilst in the three other assays they were asked to masticate bagged silicon free-style, unilaterally on the right-hand side and unilaterally on the left-hand side. The preferred chewing side was determined by calculating the asymmetry index for both the free-style assays. Masticatory performance was determined by sieving the silicon particles and the cycle duration was also recorded. Data were analysed using independent samples or paired t-test and linear regression.
RESULTS
Masticatory function using the bagged silicon was similar to that using the unbagged silicon. A significant and positive relationship was observed between the preferred chewing side expressed as the asymmetry index and the side with better masticatory performance. Alternate unilateral chewers demonstrated better masticatory performance than unilateral chewers. However, when free-style and unilateral chewing were compared for each subject, unilateral chewing was found to be as efficient as - or even more efficient than - free-style chewing.
CONCLUSIONS
There is a positive association between the preferred chewing side and the more efficient side. Alternate unilateral mastication per se does not promote better masticatory performance than consistently unilateral mastication.
Topics: Adult; Cross-Sectional Studies; Female; Functional Laterality; Humans; Male; Mastication; Middle Aged; Reproducibility of Results; Video Recording
PubMed: 25173664
DOI: 10.1016/j.archoralbio.2014.08.005 -
International Journal of Environmental... Mar 2022We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home...
We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home care. Seventy-two participants were instructed to freely crush the test foods soft jelly (SJ) and hard jelly (HJ). We visually evaluated the crushability of the test food and identified the intraoral tissues (active sites) used to crush the test food. The active sites were consistent for all participants for both SJ and HJ, and they included the maxillary and mandibular teeth in 41 participants, teeth and residual ridges in 15 participants, maxillary and mandibular residual ridges in 10 participants, and tongue and palate in six participants. Two participants failed to crush the SJ; the active sites in both participants were the tongue and palate. No participant using the tongue and palate as active sites could crush the HJ. Furthermore, 64 participants could crush the SJ and 23 could crush the HJ using the tongue and palate. The cutoff value of the tongue pressure for crushability of the HJ was 22.0 kPa. Assessing tongue pressure and intraoral active sites involved in food crushing could help determine an appropriate diet for older adults requiring nursing home care.
Topics: Aged; Food; Humans; Mastication; Nursing Homes; Pilot Projects; Pressure; Tongue
PubMed: 35329105
DOI: 10.3390/ijerph19063419 -
Scientific Reports Aug 2022The gut environment, including the microbiota and its metabolites and short-chain fatty acids (SCFA), is essential for health maintenance. It is considered that...
The gut environment, including the microbiota and its metabolites and short-chain fatty acids (SCFA), is essential for health maintenance. It is considered that functional recovery treatment for masticatory dysphagia affects the composition of the gut microbiota, indicating that habitual mastication, depending on the hardness of the food, may affect the gut microbiota and environment. However, the impact of chronic powdered diet feeding on the colonic condition and motility remains unclear. Here, we evaluated various colonic features in mice fed with powdered diets for a long-term and a mouse model with masticatory behavior. We observed a decreased abundance of the SCFA-producing bacterial genera in the ceca of the powdered diet-fed mice. Based on the importance of SCFAs in gut immune homeostasis and motility, interestingly, powdered diet feeding also resulted in constipation-like symptoms due to mild colitis, which were ameliorated by the administration of a neutrophil-depleting agent and neutrophil elastase inhibitors. Lastly, the suppressed colonic motility in the powdered diet-fed mice was significantly improved by loading masticatory activity for 2 h. Thus, feeding habits with appropriate masticatory activity and stimulation may play a key role in providing a favorable gut environment based on interactions between the gut microbiota and host immune system.
Topics: Animals; Colitis; Fatty Acids, Volatile; Gastrointestinal Microbiome; Mastication; Mice; Microbiota
PubMed: 35970869
DOI: 10.1038/s41598-022-18095-x -
Dental Materials : Official Publication... Jan 2021Mechanical damages can occur from dental restoration processing and fitting, or while it is in-service. This study evaluates the damage sensitivity of translucent...
OBJECTIVE
Mechanical damages can occur from dental restoration processing and fitting, or while it is in-service. This study evaluates the damage sensitivity of translucent zirconia (5Y-PSZ) relative to conventional 3Y-PSZ following mouth-motion simulations at various loads.
METHODS
5Y-PSZ and 3Y-PSZ discs were adhesively bonded to a dentin-like substrate and divided into groups according to the load (50 N or 200 N) and number of cycles (up to 10) used in the chewing simulation. Specimens were mounted with 30° inclination in an electrodynamic mouth-motion simulator, and subjected to contact-slide-liftoff cyclic loading in water. Surface and sub-surface damages were analyzed using a sectioning technique. After the simulation, specimens were removed from the substrate and loaded with the damaged surface in tension for biaxial strength testing to assess their damage tolerance.
RESULTS
The strength of both ceramics underwent significant degradation after mouth-motion simulations. For 5Y-PSZ, the strength degradation was greater (∼60%) and occurred at a lower number of cycles than 3Y-PSZ. Herringbone cracks emerged on 3Y-PSZ and 5Y-PSZ surfaces under a 200-N load after 50 and 10 cycles, respectively. Meanwhile at a 50-N load, cracks formed at ∼1000 cycles in both ceramics. Further increasing the number of cycles only had moderate effects on the strength of both ceramics, despite an increase in surface and sub-surface damage. More significantly, a 50-N occlusal load can debase the zirconia strengths as much as a 200-N load.
SIGNIFICANCE
Surface flaws produced during the chewing simulation are capable of significant strength degradation in zirconia, even after a small number of low-load cycles.
Topics: Ceramics; Dental Porcelain; Dental Stress Analysis; Mastication; Materials Testing; Surface Properties; Zirconium
PubMed: 33234315
DOI: 10.1016/j.dental.2020.10.019 -
Clinical Interventions in Aging 2017To evaluate the effect of age and chosen factors related to aging such as dentition, muscle strength, and nutrition on masticatory muscles electromyographic activity...
OBJECTIVES
To evaluate the effect of age and chosen factors related to aging such as dentition, muscle strength, and nutrition on masticatory muscles electromyographic activity during chewing in healthy elderly women.
BACKGROUND
With longer lifespan there is a need for maintaining optimal quality of life and health in older age. Skeletal muscle strength deteriorates in older age. This deterioration is also observed within masticatory muscles.
METHODS
A total of 30 women, aged 68-92 years, were included in the study: 10 individuals had natural functional dentition, 10 were missing posterior teeth in the upper and lower jaw reconstructed with removable partial dentures, and 10 were edontoulous, using complete removable dentures. Surface electromyography was performed to evaluate masticatory muscles activity. Afterwards, measurement of masseter thickness with ultrasound imaging was performed, body mass index and body cell mass index were calculated, and isometric handgrip strength was measured.
RESULTS
Isometric maximal voluntary contraction decreased in active masseters with increasing age and in active and passive temporalis muscles with increasing age and increasing body mass index. In active masseter, mean electromyographic activity during the sequence (time from the start of chewing till the end when the test food became ready to swallow) decreased with increasing age and during the cycle (single bite time) decreased with increasing age and increasing body mass index. In active and passive temporalis muscles, mean electromyographic activity during the sequence and the cycle decreased with increasing age, increasing body mass index, and loss of natural dentition. Individuals with natural dentition had significantly higher mean muscle activity during sequence and cycle in active temporalis muscles than those wearing full dentures and higher maximal activity during cycle in individuals with active and passive temporalis muscles than in complete denture wearers.
CONCLUSION
Decrease in electromyographic activity of masticatory muscles in elderly women is related to age, deterioration of dental status, and body mass index.
Topics: Aged; Aged, 80 and over; Aging; Body Mass Index; Dentition; Electromyography; Female; Humans; Masseter Muscle; Mastication; Masticatory Muscles; Muscle Strength; Nutritional Status; Pilot Projects; Quality of Life
PubMed: 28138227
DOI: 10.2147/CIA.S118338