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BMC Oral Health May 2018A substantial number of adults suffer from obesity, that is caused by the risk factor, masticatory dysfunction. The association between mastication and obesity, however,...
BACKGROUND
A substantial number of adults suffer from obesity, that is caused by the risk factor, masticatory dysfunction. The association between mastication and obesity, however, is inconclusive. This systematic review aims to provide literature regarding the association between mastication and factors affecting masticatory function, and obesity in adults.
METHODS
Four electronic databases (PubMed, EMBASE, Cochrane Library, and Web of Science) were used to search for publications that met the following criteria: published between 2007 and 2016, written in English, and assessed the associations between mastication and obesity among the population aged ≥18 years. The included publications were analyzed based on the study design, main conclusions, and strength of evidence identified by the two authors who screened all the abstracts and full-text articles and, abstracted data, and performed quality assessments by using a critical appraisal tool, the Critical Appraisal Skills Programme Cohort Studies Checklists.
RESULTS
A total of 18 articles (16 cross-sectional, 1 cohort studies, and 1 randomized controlled trial [RCT]) met our inclusion criteria and were evaluated. Poorer mastication was associated with obesity in 12 out of 16 cross-sectional studies. One cohort study showed that the obesity group displayed higher tooth loss than the normal weight group. One RCT demonstrated that gum-chewing intervention for 8 weeks significantly decreased waist circumference.
CONCLUSIONS
Most studies revealed a positive association between mastication and obesity among adults. Nonetheless, most of them are cross-sectional studies, which are insufficient to demonstrate a causal relation. Further advancement requires RCT, especially an intervention of improvement of mastication and obesity needed to confirm this association.
Topics: Adult; Humans; Mastication; Obesity
PubMed: 29728079
DOI: 10.1186/s12903-018-0525-3 -
International Journal of Environmental... Aug 2022Oral dysfunction is related to long-term cares including activities of daily living. The objective of this study was to determine the association between oral function...
BACKGROUND
Oral dysfunction is related to long-term cares including activities of daily living. The objective of this study was to determine the association between oral function and the bone-related physiological substances osteocalcin (OC) and insulin-like growth factor-1 (IGF-1).
METHODS
The study participants were 139 community-dwelling older people in Japan. Evaluation of oral dysfunction was based on subjective judgment by each participant. Blood analysis included OC, IGF-1, and albumin.
RESULTS
Univariate and multiple logistic analyses showed that IGF-1 was significantly associated with a "decline in masticatory function" ( = 0.0074 and = 0.0308, respectively). Receiver operating characteristic curve analysis of IGF-1 levels revealed a threshold score of 108 ng/mL ( < 0.01) for discriminating a "decline in masticatory function". Logistic regression analysis revealed that participants with an IGF-1 level ≤108 ng/mL had an odds ratio of 4.31 ( < 0.05) for a "decline in masticatory function". No significant association was found between the OC level and oral dysfunction.
CONCLUSIONS
These results suggest a possible relationship between lower serum IGF-1 levels and a decline in masticatory dysfunction in community-dwelling older people.
Topics: Activities of Daily Living; Aged; Cross-Sectional Studies; Humans; Independent Living; Insulin-Like Growth Factor I; Japan; Mastication; Oral Health; Osteocalcin
PubMed: 36078393
DOI: 10.3390/ijerph191710677 -
BioMed Research International 2015The acute effects of chewing gum on cognitive performance, stress, and pain have been intensively studied in the last decade. The results have been contradicting, and... (Review)
Review
The acute effects of chewing gum on cognitive performance, stress, and pain have been intensively studied in the last decade. The results have been contradicting, and replication studies proved challenging. Here, we review some of the recent findings of this topic and explore possible explanations for these discrepancies by incorporating knowledge derived from studies into oral habits and bruxism. Both stress and cerebral functional specialization (i.e., the involvement of specific brain structures in distinctive cognitive processes) are hypothesized to play a major role in the underlying physiological mechanisms of the diverse effects of chewing gum on cognition, stress, and pain.
Topics: Adaptation, Psychological; Brain; Bruxism; Chewing Gum; Cognition; Habits; Humans; Mastication; Pain
PubMed: 26090381
DOI: 10.1155/2015/149431 -
Dysphagia Oct 2017This study determines if older adults can masticate regular foods via a simple test conducted using a color-changeable chewing gum. Seventy-nine consecutive inpatients...
This study determines if older adults can masticate regular foods via a simple test conducted using a color-changeable chewing gum. Seventy-nine consecutive inpatients of our clinic receiving rehabilitation and general medicine were assessed for eligibility. The inclusion criterion was >65 years. Thirty patients consented to participate. The main outcome variable was the food bolus texture at the swallowing threshold for five regular foods. The main explanatory variable was the a* value of the color-changeable chewing gum after 120 s of chewing (a* represents the degree of color between red and green, and a positive a* value indicates red). The mean age ± standard deviation of the participants was 81.6 ± 8.6 years, and 40% were men. Participants being able to prepare the food with suitable texture for swallowing was positively associated with the a* values in boiled rice, ginger-fried pork loin, boiled fish-paste, and rice cracker (Crude OR 1.18, 1.15, 1.17, and 1.50; P < 0.001, = 0.026, <0.001, and <0.001, respectively). The cut-off a* values had markedly high specificities (1.0) for boiled rice and boiled fish-paste and high sensitivities (0.86-0.94) for three foods, except boiled rice. We believe that mastication evaluation using the color-changeable chewing gum is not only useful but also extremely practical, even for older adults in a wide range of settings, including an individual's home. This approach would lead to a reduction in unnecessary mechanically altered or pureed food for older adults who can eat pureed food and safely provide palatable food.
Topics: Aged; Aged, 80 and over; Chewing Gum; Color; Cross-Sectional Studies; Deglutition; Female; Food; Humans; Male; Mastication
PubMed: 28474132
DOI: 10.1007/s00455-017-9807-1 -
Scientific Reports Jun 2021Although a functional relationship between bone structure and mastication has been shown in some regions of the rabbit skull, the biomechanics of the whole cranium...
Although a functional relationship between bone structure and mastication has been shown in some regions of the rabbit skull, the biomechanics of the whole cranium during mastication have yet to be fully explored. In terms of cranial biomechanics, the rabbit is a particularly interesting species due to its uniquely fenestrated rostrum, the mechanical function of which is debated. In addition, the rabbit processes food through incisor and molar biting within a single bite cycle, and the potential influence of these bite modes on skull biomechanics remains unknown. This study combined the in silico methods of multi-body dynamics and finite element analysis to compute musculoskeletal forces associated with a range of incisor and molar biting, and to predict the associated strains. The results show that the majority of the cranium, including the fenestrated rostrum, transmits masticatory strains. The peak strains generated over all bites were found to be attributed to both incisor and molar biting. This could be a consequence of a skull shape adapted to promote an even strain distribution for a combination of infrequent incisor bites and cyclic molar bites. However, some regions, such as the supraorbital process, experienced low peak strain for all masticatory loads considered, suggesting such regions are not designed to resist masticatory forces.
Topics: Animals; Biomechanical Phenomena; Cephalometry; Computer Simulation; Finite Element Analysis; Incisor; Masseter Muscle; Mastication; Maxilla; Models, Biological; Molar; Rabbits; Skull; Stress, Mechanical; Weight-Bearing
PubMed: 34162932
DOI: 10.1038/s41598-021-92558-5 -
Biomechanics and Modeling in... Aug 2015Owing to economic conditions, removable dentures remain popular despite the discomfort and reduced chewing efficiency experienced by most denture wearers. However, there... (Review)
Review
Owing to economic conditions, removable dentures remain popular despite the discomfort and reduced chewing efficiency experienced by most denture wearers. However, there is little evidence to confirm that the level of mucosal load exceeds the pressure pain threshold. This discrepancy stimulated us to review the current state of knowledge on the biomechanics of mastication with complete removable dentures. The loading beneath dentures was analyzed in the context of denture foundation characteristics, salivary lubrication, occlusal forces, and the biomechanics of mastication. The analysis revealed that the interpretation of data collected in vivo is hindered due to the simultaneous overlapping effects of many variables. In turn, problems with determining the pressure beneath a denture and analyzing frictional processes constitute principal limitations of in vitro model studies. Predefined conditions of finite element method simulations should include the effects of oblique mastication forces, simultaneous detachment and sliding of the denture on its foundation, and the stabilizing role of balancing contacts. This review establishes that previous investigations may have failed because of their unsubstantiated assumption that, in a well-working balanced occlusion, force is only exerted perpendicular to the occlusal plane, allowing the denture to sit firmly on its foundation. Recent improvements in the simulation of realistic biomechanical denture behavior raise the possibility of assessing the effects of denture design on the pressures and slides beneath the denture.
Topics: Biomechanical Phenomena; Dental Occlusion; Denture, Complete; Humans; Lubrication; Mastication; Saliva
PubMed: 25527034
DOI: 10.1007/s10237-014-0642-0 -
The British Journal of Nutrition Feb 2020The bioaccessibility of fat has implications for satiety and postprandial lipidaemia. The prevailing view holds that the integrity of plant cell wall structure is the...
The bioaccessibility of fat has implications for satiety and postprandial lipidaemia. The prevailing view holds that the integrity of plant cell wall structure is the primary determinant of energy and nutrient extraction from plant cells as they pass through the gastrointestinal (GI) tract. However, comparisons across nuts (walnuts, almonds and pistachios) with varying physical properties do not support this view. In the present study, masticated samples of three nuts from healthy adults were exposed to a static model of gastric digestion followed by simulated intestinal digestion. Primary outcomes were particle size and lipid release at each phase of digestion. Walnuts produced a significantly larger particle size post-mastication compared with almonds. Under gastric and intestinal conditions, the particle size was larger for walnuts compared with pistachios and almonds (P < 0·05). However, the masticated and digesta particle sizes were not related to the integrity of cell walls or lipid release. The total lipid release was comparable between nuts after the in vitro intestinal phase (P > 0·05). Microstructural examination showed ruptured and fissured cell walls that would allow digestion of cellular contents, and this may be governed by internal cellular properties such as oil body state. Furthermore, the cell walls of walnuts tend to rupture rather than separate and as walnut tissue passes through the GI tract, lipids tend to coalesce reducing digestion efficiency.
Topics: Adult; Biological Availability; Computer Simulation; Dietary Fats; Digestion; Energy Metabolism; Female; Gastrointestinal Tract; Humans; Hyperlipidemias; Juglans; Lipids; Male; Mastication; Particle Size; Pistacia; Postprandial Period; Prunus dulcis; Satiation
PubMed: 31619299
DOI: 10.1017/S0007114519002630 -
BMC Geriatrics May 2022Physiological deterioration (aging, poor dental status, and reduced tongue pressure) makes chewing difficult. This study aimed to investigate the chewing patterns of...
BACKGROUND
Physiological deterioration (aging, poor dental status, and reduced tongue pressure) makes chewing difficult. This study aimed to investigate the chewing patterns of older people with or without dentures, evaluate the textural and masticatory properties of texture-modified radish Kimchi, and investigate the correlation between dental status and tongue pressure. Additionally, differences in the subjective-objective concordance of texture-modified Kimchi were investigated using the preference test.
METHODS
This study included 32 Korean women aged between 65 and 85 years. Masticatory behavior was recorded by electromyography, and tongue pressure was measured using the Iowa Oral Performance Instrument. A preference test, with hardness as the relevant textural property, determined the participants' preferences among the test samples (food with a homogeneous structure-radish Kimchi). To assess preference differences, a questionnaire suitable for older people was designed. The preference for cooked radish Kimchi with various blanching times based on overall acceptability and self-reporting of preference was investigated to develop elderly-friendly food. The subjective scores indicated whether the sample (radish Kimchi) was hard or soft based on the chewing ability of the participants. Dental status, muscle activities, and tongue pressure were considered for the food design with optimized texture. The relationship between subject score and mastication properties were examined using multiple regression analysis.
RESULTS
The number of chews and chewing time increased with hardness, significantly activating the masseter and temporalis muscles. The evaluation of masseter muscle activity, particularly for level-6 radish Kimchi, showed that older people with complete dentures chewed less actively than those with natural teeth (p < 0.05). The older people with natural teeth (18.94 ± 10.27 kPa) exhibited higher tongue pressure than those with complete dentures (10.81 ± 62.93 kPa), and the difference was statistically significant (p < 0.01). Older people preferred food with familiar tastes and textures. An association was found between the subjective hardness score and the objective hardness level. The perceived hardness intensity was linked to the chewing ability of the participant. Denture wearers exhibited a lower chewing ability, and at level 6, they perceived greater hardness of food than those with natural teeth.
CONCLUSIONS
Developing food with a modified texture can bridge the gap between physiological and psychological aspects of food texture; texture-modified radish Kimchi, with limited blanching time, may be favorable for older people.
Topics: Aged; Aged, 80 and over; Female; Food; Humans; Masseter Muscle; Mastication; Pressure; Tongue
PubMed: 35501716
DOI: 10.1186/s12877-022-03064-w -
Journal of the Royal Society, Interface Nov 2020Comparative laboratory sliding wear tests on extracted human molar teeth in artificial saliva with third-body particulates demonstrate that phytoliths can be as...
Comparative laboratory sliding wear tests on extracted human molar teeth in artificial saliva with third-body particulates demonstrate that phytoliths can be as effective as silica grit in the abrasion of enamel. A pin-on-disc wear testing configuration is employed, with an extracted molar cusp as a pin on a hard disc antagonist, under loading conditions representative of normal chewing forces. Concentrations and sizes of phytoliths in the wear test media match those of silica particles. Cusp geometries and ensuing abrasion volumes are measured by digital profilometry. The wear data are considered in relation to a debate by evolutionary biologists concerning the relative capacities of intrinsic mineral bodies within plant tissue and exogenous grit in the atmosphere to act as agents of tooth wear in various animal species.
Topics: Animals; Humans; Mastication; Molar; Plants; Silicon Dioxide; Tooth Wear
PubMed: 33143592
DOI: 10.1098/rsif.2020.0613 -
PloS One 2021Dentistry is confronted with the functional and aesthetic consequences that result from an increased prevalence of misaligned and discrepant dental occlusal relations in...
Dentistry is confronted with the functional and aesthetic consequences that result from an increased prevalence of misaligned and discrepant dental occlusal relations in modern industrialised societies. Previous studies have indicated that a reduction in jaw size in response to softer and more heavily processed foods during and following the Industrial Revolution (1,700 CE to present) was an important factor in increased levels of poor dental occlusion. The functional demands placed on the masticatory system play a crucial role in jaw ontogenetic development; however, the way in which chewing behaviours changed in response to the consumption of softer foods during this period remains poorly understood. Here we show that eating more heavily processed food has radically transformed occlusal power stroke kinematics. Results of virtual 3D analysis of the dental macrowear patterns of molars in 104 individuals dating to the Industrial Revolution (1,700-1,900 CE), and 130 of their medieval and early post-medieval antecedents (1,100-1,700 CE) revealed changes in masticatory behaviour that occurred during the early stages of the transition towards eating more heavily processed foods. The industrial-era groups examined chewed with a reduced transverse component of jaw movement. These results show a diminished sequence of occlusal contacts indicating that a dental revolution has taken place in modern times, involving a dramatic shift in the way in which teeth occlude and wear during mastication. Molar macrowear suggests a close connection between progressive changes in chewing since the industrialization of food production and an increase in the prevalence of poor dental occlusion in modern societies.
Topics: Biological Evolution; Biomechanical Phenomena; Dental Occlusion; Dentistry; Humans; Mastication; Molar; Tooth
PubMed: 34910787
DOI: 10.1371/journal.pone.0261404