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PloS One 2020Recent results have established that masticatory function plays a role not only in the balance of the stomatognathic system and in the central motor control, but also in...
Altered mastication adversely impacts morpho-functional features of the hippocampus: A systematic review on animal studies in three different experimental conditions involving the masticatory function.
Recent results have established that masticatory function plays a role not only in the balance of the stomatognathic system and in the central motor control, but also in the trophism of the hippocampus and in the cognitive activity. These implications have been shown in clinical studies and in animal researches as well, by means of histological, biochemical and behavioural techniques. This systematic review describes the effects of three forms of experimentally altered mastication, namely soft-diet feeding, molar extraction and bite-raising, on the trophism and function of the hippocampus in animal models. Through a systematic search of PubMed, Embase, Web of Science, Scopus, OpenGray and GrayMatters, 645 articles were identified, 33 full text articles were assessed for eligibility and 28 articles were included in the review process. The comprehensiveness of reporting was evaluated with the ARRIVE guidelines and the risk of bias with the SYRCLE RoB tool. The literature reviewed agrees that a disturbed mastication is significantly associated with a reduced number of hippocampal pyramidal neurons in Cornu Ammonis (CA)1 and CA3, downregulation of Brain Derived Neurotrophic Factor (BDNF), reduced synaptic activity, reduced neurogenesis in the Dentate Gyrus (DG), glial proliferation, and reduced performances in behavioural tests, indicating memory impairment and reduced spatial orientation. Moreover, while the bite-raised condition, characterized by occlusal instability, is known to be a source of stress, soft-diet feeding and molar extractions were not consistently associated with a stress response. More research is needed to clarify this topic. The emerging role of chewing in the preservation of hippocampal trophism, neurogenesis and synaptic activity is worthy of interest and may contribute to the study of neurodegenerative diseases in new and potentially relevant ways.
Topics: Animals; Cognition; Dentate Gyrus; Hippocampus; Humans; Mastication; Memory Disorders; Models, Animal; Neurogenesis; Neurons
PubMed: 32817680
DOI: 10.1371/journal.pone.0237872 -
Mediterranean Journal of Rheumatology Jun 2020Individuals presenting with rheumatoid arthritis (RA) frequently experience temporomandibular disorders (TMDs), which can result in limited ranges of mandibular motion,... (Review)
Review
OBJECTIVE
Individuals presenting with rheumatoid arthritis (RA) frequently experience temporomandibular disorders (TMDs), which can result in limited ranges of mandibular motion, pain and fatigue on jaw function, and impaired mastication. As such, individuals with RA-related TMDs may consume a texture-modified diet in order to reduce the exacerbation of jaw pain and dysfunction, and to increase the ease of oral intake. These softer food options may not contain the recommended nutrients, vitamins, and minerals, and therefore, may not be nutritionally optimal. As unintentional body composition and weight changes are common in individuals with RA, there may be elevated risks of obesity or malnutrition in this patient subgroup. However, minimal researcth has been conducted to investigate the use of modified diets in this cohort, and therefore, the true level of risk to these patients cannot not be adequately determined. The aim of this study was to determine the prevalence of diet modifications in adults presenting with RA affecting the TMJ.
METHODS
All available evidence presenting data on adults with RA who consume modified diets was systematically reviewed. A range of electronic databases were searched, including: EMBASE, PubMed, CINAHL, Web of Science, Elsevier Scopus, Science Direct, AMED, The Cochrane Database of Systematic Reviews, and ProQuest Dissertations and Theses A & I. Supplementary Google Scholar, reference list, and grey literature searches were also conducted. Independent reviewers assessed study eligibility, and methodological quality was rated using the Down's and Black assessment.
RESULTS
One study was eligible for inclusion, and half (50.82%; CI: 37.7-63.86) of individuals with RA in this study consumed a modified diet. This study was rated to be of moderate quality. The primary limitation of this review was the lack of studies on this topic which were available for inclusion.
CONCLUSIONS
Although from clinical practice, it is recognised that adults with TMD related to RA do modify their diets to cope with the functional impairment of TMD, this review confirms that minimal research has been conducted regarding the use of texture modified diets by this population. This is despite concerns regarding unintentional weight changes in this patient group. Further research investigating this area is warranted in order to improve patient outcomes and experience of care.
PubMed: 32676555
DOI: 10.31138/mjr.31.2.183 -
International Dental Journal Oct 2019A relationship between masticatory function and cognition has been reported. It is proposed that mastication changes the blood flow stimulating the perfusion/oxygenation...
INTRODUCTION
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.
MATERIALS AND 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.
CONCLUSION
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.
Topics: Adult; Cognition; Cognitive Dysfunction; Humans; Learning; Mastication; Protective Factors
PubMed: 31140598
DOI: 10.1111/idj.12486 -
Clinical and Experimental Dental... Feb 2019The objectives of this study is to identify methods for objectively assessing masticatory performance (MP) and to evaluate their measurement properties. A secondary...
The objectives of this study is to identify methods for objectively assessing masticatory performance (MP) and to evaluate their measurement properties. A secondary objective was to identify any reported adverse events associated with the methods to assess MP. Bibliographic databases were searched, including MEDLINE, Embase, Web of Science Core Collection, Cochrane, and Cinahl databases. Eligible papers that satisfied predefined inclusion and exclusion criteria were appraised independently by two investigators. Four other investigators independently appraised any measurement properties of the assessment method according to the consensus-based standards for the selection of health measurement instruments checklist. The qualities of the measurement properties were evaluated using predefined criteria. The level of evidence was rated by using data synthesis for each MP assessment method, where the rating was a product of methodological quality and measurement properties quality. All studies were quality assessed separately, initially, and subsequently for each method. Studies that described the use of identical assessment method received an individual score, and the pooled sum score resulted in an overall evidence synthesis. The level of evidence was synthesized across studies with an overall conclusion, that is, unknown, conflicting, limited, moderate, or strong evidence. Forty-six out of 9,908 articles were appraised, and the assessment methods were categorized as comminution ( = 21), mixing ability ( = 23), or other methods ( = 2). Different measurement properties were identified, in decreasing order construct validity ( = 30), reliability ( = 22), measurement error ( = 9), criterion validity ( = 6), and responsiveness ( = 4). No adverse events associated with any assessment methods were reported. In a clinical setting or as a diagnostic method, there are no gold standard methods for assessing MP with a strong level of evidence for all measurement properties. All available assessment methods with variable level of evidence require lab-intensive equipment, such as sieves or digital image software. Clinical trials with sufficient sample size, to infer trueness and precision, are needed for evaluating diagnostic values of available methods for assessing masticatory performance.
Topics: Bite Force; Checklist; Humans; Mastication; Oral Health; Reproducibility of Results; Stomatognathic System
PubMed: 30847236
DOI: 10.1002/cre2.154 -
Head & Neck Jan 2019Segmental mandibulectomy impairs health-related quality of life (QoL), by altering speech, mastication, swallowing, and facial aesthetics. Fibula free flap (FFF) used...
BACKGROUND
Segmental mandibulectomy impairs health-related quality of life (QoL), by altering speech, mastication, swallowing, and facial aesthetics. Fibula free flap (FFF) used for mandible reconstruction is known to improve outcomes; however, minimal information exists in the literature regarding patient-reported outcomes. We aim to assess how current studies evaluate patient perception following segmental mandibulectomy and FFF mandible reconstruction.
METHODS
Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a search was conducted for publications involving FFF mandible reconstruction from 2005 to 2017 using PubMed, Cochrane, EMBASE, Web of Science, and PsychInfo.
RESULTS
Of 2212 articles identified initially, only 7 studies were deemed suitable. Six studies used the University of Washington Quality of Life questionnaire, 3 Oral Health Impact Profile, and 1 used European Organization for Research and Treatment of Cancer Head and Neck (EORTC-H&N35).
CONCLUSIONS
There is a paucity of information in published reports on QoL outcomes following mandible reconstruction with FFF. In the era of patient-centered health care, observations warrant attention from researchers for physician-assessed patient-reported measures to factor in QoL expectation during surgical decision-making about the choice of reconstruction.
Topics: Esthetics; Fibula; Free Tissue Flaps; Humans; Mandible; Mandibular Reconstruction; Patient Reported Outcome Measures; Quality of Life; Surveys and Questionnaires
PubMed: 30548509
DOI: 10.1002/hed.25452 -
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 -
PloS One 2018Khat chewing has become a common practice among university students in developing countries like Ethiopia. It has a potential effect on physical, mental, social and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Khat chewing has become a common practice among university students in developing countries like Ethiopia. It has a potential effect on physical, mental, social and cognitive aspects of student functioning. In Ethiopia, study findings regarding the prevalence of khat chewing were highly dispersed and inconsistent. Therefore, this systematic review and meta-analysis estimates the pooled prevalence of khat chewing and its predictors among Ethiopian university students.
METHOD
A systematic review and meta-analysis was conducted to assess the prevalence and predictors of khat chewing among university students in Ethiopia. We searched literature from the databases of PubMed, Google Scholar, Science Direct, and the Cochrane Library. A total of 24 Ethiopian studies reporting the prevalence of khat chewing among university students were included. Data were extracted using a standardized data extraction format prepared in Microsoft Excel and the analysis was done using STATA 14 statistical software. To assess heterogeneity, the Cochrane Q test statistics and I2 test were used. Since the included studies exhibit high heterogeneity, a random effect meta-analysis model was computed to estimate the pooled prevalence of khat chewing. Moreover, the association between predictor variables, and khat chewing practice were examined.
RESULTS
The meta-analysis of 24 studies revealed that the pooled prevalence of khat chewing among university students in Ethiopia was 23.22% (95% CI: 19.5, 27.0). In the subgroup analysis, the highest prevalence was observed in Oromia region (31.6%; 95CI: 21.2, 41.9) whereas the lowest prevalence was observed in Amhara region (18.1%; 95%CI: 12.4, 23.8). Being male OR: 2.76 (95% CI 1.64, 4.63), family khat chewing practice OR: 2.91 (95% CI 1.06, 7.98), friend khat chewing habit OR: 4.74 (95% CI 3.48, 13.06), alcohol drinking OR: 7.06 (95% CI 5.65, 8.82) and cigarette smoking habit OR: 15.11 (95% CI 8.96, 25.51) were found to be predictors of khat chewing.
CONCLUSION
The study found that the prevalence of khat chewing among university students was quite common, with slightly more than 1 in 5 students engaging in the use of this substance. Being male, family khat chewing practice, friend's khat chewing habit, alcohol drinking, and cigarette smoking were found to be predictors of khat chewing practice among university students.
Topics: Alcohol Drinking; Catha; Central Nervous System Stimulants; Cross-Sectional Studies; Ethiopia; Female; Friends; Humans; Male; Mastication; Prevalence; Risk Factors; Smoking; Students; Substance-Related Disorders; Universities; Young Adult
PubMed: 29649253
DOI: 10.1371/journal.pone.0195718 -
The Journal of Nutrition, Health & Aging 2018This systematic literature review aims to summarize the existing scientific evidence about the association between a reduced salivary function and food consumption in...
OBJECTIVES
This systematic literature review aims to summarize the existing scientific evidence about the association between a reduced salivary function and food consumption in elderly people.
METHODS
A validated search strategy in two databases (PubMed and ISI Web of Knowledge) was carried out and retrieved papers together with their reference lists were screened by two independent reviewers. The quality of the included studies was critically appraised via the Quality Assessment Criteria for Evaluating Primary Research Papers.
RESULTS
From the originally identified studies (n=391), only 15 articles (all cross-sectional studies) met the pre-fixed inclusion/exclusion criteria. The methodological quality of the included studies was in general good, although only 3 from 15 obtained the maximum score. The control of confounding factors was the quality variable more poorly rated in the selected studies. Salivary hypofunction was associated with a decrease of the objective chewing and swallowing abilities and taste perception. Moreover, most of the selected studies showed a relationship between salivary hypofunction and food consumption (in terms of appetite loss, unbalanced dietary intake and malnutrition), although no causality could be established.
CONCLUSIONS
This study highlights the fact that salivary hypofunction definition and measurements are different across the studies. Therefore, future research efforts should focus on establishing a gold standard to define and identify salivary hypofunction throughout life and on performing longitudinal studies controlling for confounding factors to establish causality.
Topics: Aged; Aged, 80 and over; Deglutition; Eating; Energy Intake; Feeding and Eating Disorders; Female; Hospitalization; Humans; Male; Mastication; Meals; Nutritional Status; Salivation; Taste Perception; Xerostomia
PubMed: 29484355
DOI: 10.1007/s12603-017-0960-x -
Appetite Jun 2018Food delivers energy, nutrients and a pleasurable experience. Slow eating and prolonged oro-sensory exposure to food during consumption can enhance the processes that... (Meta-Analysis)
Meta-Analysis
Food delivers energy, nutrients and a pleasurable experience. Slow eating and prolonged oro-sensory exposure to food during consumption can enhance the processes that promote satiation. This systematic review and meta-analysis investigated the effects of oral processing on subjective measures of appetite (hunger, desire to eat) and objectively measured food intake. The aim was to investigate the influence of oral processing characteristics, specifically "chewing" and "lubrication", on "appetite" and "food intake". A literature search of six databases (Cochrane library, PubMed, Medline, Food Science and Technology Abstracts, Web of Science, Scopus), yielded 12161 articles which were reduced to a set of 40 articles using pre-specified inclusion and exclusion criteria. A further two articles were excluded from the meta-analysis due to missing relevant data. From the remaining 38 papers, detailing 40 unique studies with 70 subgroups, raw data were extracted for meta-analysis (food intake n = 65, hunger n = 22 and desire to eat ratings n = 15) and analyzed using random effects modelling. Oral processing parameters, such as number of chews, eating rate and texture manipulation, appeared to influence food intake markedly but appetite ratings to a lesser extent. Meta-analysis confirmed a significant effect of the direct and indirect aspects of oral processing that were related to chewing on both self-reported hunger (-0.20 effect size, 95% confidence interval CI: -0.30, -0.11), and food intake (-0.28 effect size, 95% CI: -0.36, -0.19). Although lubrication is an important aspect of oral processing, few studies on its effects on appetite have been conducted. Future experiments using standardized approaches should provide a clearer understanding of the role of oral processing, including both chewing and lubrication, in promoting satiety.
Topics: Adult; Appetite; Eating; Energy Intake; Female; Humans; Hunger; Lubrication; Male; Mastication; Mouth; Young Adult
PubMed: 29408331
DOI: 10.1016/j.appet.2018.01.018 -
Head and Neck Pathology Dec 2017Pyoderma gangrenosum (PG) is a distinctive ulcerative skin disorder of unknown etiology, associated with an underlying systemic disease in up to 70% of cases. The... (Review)
Review
Pyoderma gangrenosum (PG) is a distinctive ulcerative skin disorder of unknown etiology, associated with an underlying systemic disease in up to 70% of cases. The condition is characterized by the appearance of one or more necrotic ulcers with a ragged undermined violaceous border and surrounding erythema. Lesions are often initiated by minor trauma. The condition can affect any anatomical site, however the head and neck are rarely involved. Although the oral cavity is subject to recurrent minor trauma through everyday activities such as mastication and oral hygiene, as well as during dental treatment, oral lesions appear to be extremely rare. In an effort to provide a detailed explanation of the oral manifestations of PG, a systematic search was conducted using medical databases. A total of 20 cases of PG with oral involvement were reported in the English and French literature. The objectives of this article are to present the pertinent diagnostic criteria and to discuss the differential diagnosis and therapeutic modalities.
Topics: Diagnosis, Differential; Humans; Oral Ulcer; Pyoderma Gangrenosum
PubMed: 28275955
DOI: 10.1007/s12105-017-0804-3