Gut peptides play a role in signaling appetite control in the hypothalamus. Limited knowledge exists regarding the release of these peptides in individuals with obesity before and during external stimuli. We hypothesize that the expression of gut peptides is different in the fasting and postprandial states in the scenario of obesity. PubMed/MEDLINE, Scopus, and Science Direct electronic databases were searched. The meta-analysis was performed using Review Manager Software. Randomized controlled trials that measured gut peptides in both obese and lean subjects were included in the analysis. A total of 552 subjects with obesity were enrolled in 25 trials. The gut peptide profile did not show any significant difference between obese and lean subjects for glucagon-like peptide 1 (95% confidence interval [CI], -1.21 to 0.38; P = .30), peptide YY (95% CI, -1.47 to 0.18; P = .13), and cholecystokinin (95% CI, -1.25 to 1.28; P = .98). Gut peptides are decreased by an increased high-fat, high-carbohydrate diet and by decreased chewing. There is no statistically significant difference in gut peptides between individuals with obesity and leanness in a fasting state. However, the release of gut peptides is affected in individuals with obesity following external stimuli, such as dietary interventions and chewing. Further studies are necessary to investigate the relationship between various stimuli and the release of gut peptides, as well as their impact on appetite regulation in subjects with obesity.

OBJECTIVE: This systematic review aimed to provide an overview of the most recent evidence on the association between measured masticatory function and cognitive status.
METHODS: Literature and manual searches were conducted using three electronic databases (PubMed, Web of Science and CINAHL). Observational studies published between 2011 and 2021 investigating the association between masticatory function, dementia and cognitive status in adult humans were abstracted and reviewed by three reviewers. Studies that assessed participants\' masticatory function using objective and subjective measurements and that individually examined its association with cognitive function were included. The included studies were divided into cross-sectional and cohort studies, and the quality of each study was analysed using critical appraisal skills checklists. Additionally, the main conclusions and strength of the evidence were assessed for each article.
RESULTS: A total of 21 studies (11 cross-sectional studies that objectively evaluated masticatory function, 9 cross-sectional studies that subjectively evaluated masticatory function and 1 prospective cohort study) were evaluated. The poorer masticatory function was associated with lower cognitive status even after adjusting for potential risk factors of dementia in four of 11 and six of nine cross-sectional studies where the masticatory function was respectively evaluated objectively and subjectively. One prospective cohort study also demonstrated that masticatory function, as evaluated based on measurements of occlusal force, predicted cognitive decline during the follow-up period.
CONCLUSIONS: Several studies demonstrated a positive association between masticatory function and cognitive status. However, further studies, particularly longitudinal studies, are required to determine whether the association is causal.

Masticatory function such as chewing is expected to modify human cognitive function, and/or the possibility of improving cognitive function is also predicted. This systematic review investigated whether masticatory function affects cognitive function for older/young adults. Full articles written in English from January 2000 to April 2022 were collected using PubMed and Cochrane Library. Target outcomes were cognitive function test scores, cognitive processing speed (reaction time), and masticatory function. For each research question, two independent reviewers conducted the search and screening, data extraction, quality assessment, and risk of bias assessment. The reviewers resolved any disagreements by discussion. From 226 articles retrieved, 20 were included in this review. Older adults with lower scores on the cognitive function test had lower masticatory performance, lower chewing ability, chewing difficulty, and decreased number of teeth. An increased risk of cognitive impairment was found in older adults with masticatory dysfunction. For young adults, gum chewing significantly reduced the processing speed of cognitive tasks compared to no gum chewing. Although most of the evidence included had a low level of evidence and a high risk of bias because of the research designs, the results still suggest that mastication may be a factor in improving cognitive function.

The literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol in the PubMed, Cochrane Library, LILACS, EBSCO, Scielo, between 2012 and 2022. The methodological quality was assessed by using the Newcastle-Ottawa Study Quality Assessment Scale. Mean differences and 95% confidence intervals were calculated and combined in meta-analyses. A total of 1202 participants were included in this systematic review (690 with TMD; 512 without TMD), with 22 articles being included in the qualitative analysis. Only three studies enabled the comparative analysis of the results. Ten articles showed a high methodological quality and a low risk of bias, and twelve had a low methodological quality and an increased risk of bias. The meta-analysis showed that the differences between the intervention and control groups were not statistically significant for the percentage overlapping coefficient of the anterior temporal muscle, for the masseter, and for the torque coefficient. The parameters analyzed with the compound technique for chewing showed altered mandibular functions in individuals with TMD. With the EMG method, it was possible to suggest that TMD in adult individuals causes compensatory muscle behaviors, and several changes in the masticatory function were found.

Relatively few empirical studies of pediatric chewing interventions have been published in the psychology literature. The purpose of this paper was to systematically review chewing interventions within the applied behavior analysis literature. We identified a small, but growing, behavior analytic literature demonstrating the effectiveness of various multicomponent treatment packages to teach and improve chewing skills. Future researchers should consider a range of participant characteristics, including results of oral motor assessments, explore a more extensive definition of chewing to target the complex nature of chewing as well as component skills, and examine the necessary and sufficient components of chewing interventions along with the potential benefits of multidisciplinary interventions.

The aim of this narrative review was to evaluate the possible association between orthodontic therapy and improved masticatory function. A search strategy was conducted using the PubMed database for up to January 2020 using the keywords \"mastication\" and \"orthodontics\". Only human studies investigating mastication in orthodontics settings were selected. The search strategy resulted in 1,011 articles, out of which 57 were included in the final analysis. Investigations have generally agreed that masticatory and chewing functions improved post-orthodontic and orthognathic treatments. Studies also showed improvement in the quality of life of patients\' post-orthodontic treatment. The articles examined reinforced that besides esthetic reasons, orthodontic therapy does improve the masticatory and chewing functions of individuals, ultimately enhancing their health-related quality of life.

Smokeless tobacco is the term used to describe a range of products found worldwide which individuals use to extract nicotine, but without smoking. Ways of achieving this include chewing, sniffing and placing in areas of the body where tissues are sufficiently thin for absorption to take place such as the oral mucosa or postauricular skin. In Central Australia, Aboriginal groups across a wide area have chewed wild tobacco plants, commonly known as Pituri, for countless generations. As well as inducing a sense of well-being, the habit has strong cultural significance. While some smokeless tobacco products used outside Australia are known to have a detrimental effect on oral health, particularly malignant change, little is known about Pituri. To date, reports of adverse oral outcomes have been elusive. Most Pituri research seems to have focussed on obstetric issues, arguably unexpected as the tobacco seems to be in contact with the mouth for longer than any other body tissues. The following report describes a lesion on the anterior buccal mucosa resulting from prolonged Pituri use. The relevant literature is reviewed. A clinical and ethical management dilemma arises between respecting the associated cultural issues and ignoring an apparent pathological entity. © 2022 Australian Dental Association.

BACKGROUND: A relationship between masticatory function and cognition has been reported. It is proposed that mastication changes the blood flow stimulating the perfusion/oxygenation of the brain. This literature review analysed the relation between mastication as a protective factor of the cognitive decline and the changes produced at brain level in adults associated with the brain blood flow.
METHODS: A systematic review was performed according to the \'Preferred Reporting Items for Systematic Reviews and Meta-Analyses\' (PRISMA) criteria in PubMed/MEDLINE, Web of Science, Scopus and Embase. Primary studies were included with no limit on the publication date, conducted on humans, and that established a relation between mastication, brain blood flow and cognitive functions in adult patients.
RESULTS: Nine clinical descriptive studies were selected and qualitatively analysed. The collected data suggest the greatest brain areas activated during mastication were the frontotemporal cortex, the caudate nucleus and the thalamus, revealing a positive correlation between chewing intensity and perfusion of the principal trigeminal nucleus. The increase in cerebral blood flow was measured by a local vasodilator effect resulting in increased neuronal metabolism in the region linked to learning and memory. In addition, partially edentulous participants had a marked prefrontal deactivation when they chewed without a prosthesis and presented a decrease in masticatory activity.
CONCLUSIONS: Masticatory function may act as a protective factor in those patients with cognition impairment and neurodegenerative diseases, suggesting some mechanisms among which is the increase of cerebral blood flow.

The aims of this paper are to conduct: 1) a systematic review of the effects of mastication on sustained attention, and 2) a meta-analysis of the effects of mastication on the performance of participants undertaking cognitive tests. Papers were obtained from MEDLINE and PsycInfo using a systematic approach incorporating defined inclusion and exclusion criteria. Twenty-one papers linking mastication and sustained attention were reviewed. Meta-analysis detected a weak, but statistically significant, improvement in levels of sustained attention when chewing with low between-study heterogeneity (mean Cohen\'s d = -0.1479 standard deviations, 95% CI [-0.2913, -0.0045], p = 0.043 & I2 = 0.00%), and a tendency for feelings of alertness to decrease less during cognitive demanding tasks when chewing (mean Cohen\'s d = 0.3797 standard deviations, 95% CI [-0.0053, 0.7647], p = 0.052 &I2 = 70.94%). To better understand the effects of mastication on sustained attention and alertness, further research is required which refines existing protocols, eliminates confounding effects such as gum formulation and constituents, and investigates the effects of contiguity, rate, and intensity of chewing.

The distribution of food particles in a chewed bolus characterizes the food destruction after food oral processing (FOP). Previous reviews report that it could be affected by a lot of parameters as the number of chewing strokes, the dental status, but the conditions for producing reproducible data allowing inter-studies comparison have not been clearly described yet. This systematic review aims to identify the variables that can affect bolus granulometry determination, and to calculate their relative weights in the median particle size (D50 ) variations. The systematic review focuses on granulometry expressed as D50 of the most used foods (peanuts, carrots, and almonds) and materials (Optosil and Optocal). Based on 58 studies, 5 variables among 60 being extracted could explain the D50 variations. Conceptual differences between the conditions for FOP should be considered. After Chewing-test, the bolus is collected after a predefined number of strokes and its granulometry characterizes the effects of the dental and muscular apparatus on food destruction, while after Mastication-test the bolus is collected at the swallowing threshold, and its granulometry reflects the outcome of the abilities of the subject to adapt his/her mastication behavior to food texture. Experimental conditions related either to physical sieving or image analysis used to analyze the collected boluses impact the D50 values. Finally, when type of test, sieving conditions, type of food or material, number of chewing strokes, and the oral status of the subjects are controlled, mean D50 values are reproducible and could be used for inter-studies comparisons. PRACTICAL APPLICATIONS: This review provides tables that could be useful to control mean D50 variations in further research.