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Aging Mar 2023
Topics: Humans; Animals; Mice; Aged; Frailty; Mastication; Frail Elderly
PubMed: 36996489
DOI: 10.18632/aging.204568 -
Journal of Dental Research Oct 2023The capacity of a tissue to continuously alter its phenotype lies at the heart of how an animal is able to quickly adapt to changes in environmental stimuli. Within...
The capacity of a tissue to continuously alter its phenotype lies at the heart of how an animal is able to quickly adapt to changes in environmental stimuli. Within tissues, differentiated cells are rigid and play a limited role in adapting to new environments; however, differentiated cells are replenished by stem cells that are defined by their phenotypic plasticity. Here we demonstrate that a Wnt-responsive stem cell niche in the junctional epithelium is responsible for the capability of this tissue to quickly adapt to changes in the physical consistency of a diet. Mechanical input from chewing is required to both establish and maintain this niche. Since the junctional epithelium directly attaches to the tooth surface via hemidesmosomes, a soft diet requires minimal mastication, and consequently, lower distortional strains are produced in the tissue. This reduced strain state is accompanied by reduced mitotic activity in both stem cells and their progeny, leading to tissue atrophy. The atrophied junctional epithelium exhibits suboptimal barrier functions, allowing the ingression of bacteria into the underlying connective tissues, which in turn trigger inflammation and mild alveolar bone loss. These data link the mechanics of chewing to the biology of tooth-supporting tissues, revealing how a stem cell niche is responsible for the remarkable adaptability of the junctional epithelium to different diets.
Topics: Animals; Epithelial Attachment; Gingiva; Mastication; Connective Tissue; Biology; Epithelium
PubMed: 37555395
DOI: 10.1177/00220345231185288 -
Gerodontology Jun 2023The present systematic review and meta-analysis aimed to summarise the current information on the masticatory function of stroke patients. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The present systematic review and meta-analysis aimed to summarise the current information on the masticatory function of stroke patients.
METHODS
Four electronic databases (Medline, Embase, CINAHL and Web of Science) were searched for relevant observational studies and clinical trials (up to Jun 2021) on the masticatory function of stroke patients. Two reviewers independently performed study selection and quality assessments (using JBI Critical Appraisal Checklist). Meta-analysis was conducted for the comparison of bite force and masticatory performance using standardised mean difference (SMD). Of the 3837 records identified, nine studies, corresponding to 11 papers and 302 participants, were included in the analysis.
RESULTS
The maximum bite force of stroke patients was significantly lower than that of the healthy individuals (SMD -0.52, 95% CI: -0.95 to -0.08, P = .02). There was no significant difference between the ipsi-lesional and the contra-lesional sides of the same stroke patient (SMD 0.13, 95% CI: -0.14 to 0.39, P = .34). Stroke patients had lower masticatory performance than healthy people (SMD -0.97, 95% CI: 0.57 to 1.37, P < .00001), and the contra-lesional side was worse than the ipsi-lesional side. Electromyographic analysis indicated that muscle activation of stroke patients was poorer than the healthy individuals, and stroke patients seem to exhibit dysfunction in the recruiting and firing of motor units.
CONCLUSIONS
Stroke patients have lower maximum bite force and masticatory performance than healthy people, with masticatory performance being the most affected.
Topics: Humans; Stroke; Stroke Rehabilitation; Bite Force; Masticatory Muscles; Mastication
PubMed: 36004768
DOI: 10.1111/ger.12653 -
CoDAS 2022To present the Myofunctional Orofacial Clinical Examination Protocol belonging to the MMBGR Protocol - Infants and Preschoolers, including its validation.
PURPOSE
To present the Myofunctional Orofacial Clinical Examination Protocol belonging to the MMBGR Protocol - Infants and Preschoolers, including its validation.
METHODS
Initially, test content-based validity was evaluated from the MBGR Protocol to be used with the age group between 6 and 71 months based on the bibliography and experience between the authors (original and current). For the content and appearance analysis, 10 speech therapists specialized in Orofacial Motricity attended and filled out an electronic form with dichotic and Likert scale questions in two moments. We used the Content Validity Index and the Exact Binomial Test. Then there was a validity based on the response processes analysis followed by a reliability of the Clinical Examination with 155 participants by 7 experienced and calibrated speech therapists, and the examiners between and within agreement was verified by the Intraclass Correlation Coefficient.
RESULTS
There were additions, modifications, and exclusions of items according to the age group, resulting in the Myofunctional Orofacial Clinical Examination Protocol for Infants and Preschoolers, which obtained 90.5% agreement; and 100% of the appropriate scores by at least 90% of the specialists. In reliability, most items of the Extraoral and Intraoral Examination and Chewing obtained a reasonable to good, or even excellent, agreement.
CONCLUSION
The "Clinical Myofunctional Clinical Examination" was validated based on the test content, response process, and reliability and, along with the "Instructional" and the "Clinical History" is part of the "MMBGR Protocol - Infants and Preschoolers" for speech therapy activities in the age group between 6 and 71 months of age.
Topics: Child, Preschool; Clinical Protocols; Humans; Infant; Mastication; Reproducibility of Results
PubMed: 35475847
DOI: 10.1590/2317-1782/20212020325 -
Journal of the Chinese Medical... Oct 2019
Topics: Adult; Foreign Bodies; Humans; Mastication; Retrospective Studies; Upper Gastrointestinal Tract
PubMed: 31385868
DOI: 10.1097/JCMA.0000000000000167 -
European Journal of Pain (London,... Nov 2022Parkinson's disease (PD) is commonly known as a disorder that affects the smooth performance of body movements. In addition to the motor impairments, patients with PD... (Review)
Review
BACKGROUND
Parkinson's disease (PD) is commonly known as a disorder that affects the smooth performance of body movements. In addition to the motor impairments, patients with PD often experience pain. Both motor impairments and pain can occur throughout the body, hence including the orofacial region. However, currently, there is a lack of knowledge on the orofacial manifestations. Since orofacial pain and dysfunction can, amongst others, reduce the quality of life of patients with PD, it is important to explore the prevalence of these symptoms in the PD population.
OBJECTIVE
To provide a broad overview of the relevant literature on orofacial pain and dysfunction in patients with PD. Furthermore, we aim to generate hypotheses for future research on this topic.
DATABASES AND DATA TREATMENT
A literature search (in PubMed, Embase.com, Web of Science [Core collection], and Cochrane Library) was performed on 20 January 2022, in collaboration with a medical librarian. In total, 7180 articles were found, of which 50 were finally included in this scoping review.
RESULTS
In the included studies, pain (e.g. orofacial pain (N = 2) and temporomandibular disorder pain (N = 2)), orofacial motor dysfunction (e.g. limited jaw movements (N = 10), reduced maximum muscle output (N = 3), chewing difficulties (N = 9), unspecified TMD (N = 3), sensory disturbances (N = 1)), and bruxism (N = 3) were observed more often in patients with PD than in healthy controls.
CONCLUSION
Patients with PD experience more pain in the orofacial area and more dysfunction of the masticatory system than their healthy peers.
SIGNIFICANCE
This scoping review can increase health care providers' awareness of the problems that can be encountered in the orofacial area of PD patients, especially pain syndromes also occur in the orofacial region and not only in the extremities. Besides, dysfunction of the orofacial area is elaborated in this scoping review, which helps to understand that this limits PD patients' quality of life. Further, the outcomes of this scoping review can assist in encouraging collaboration between medicine and dentistry. Finally, this scoping review suggests new research areas, based on the gaps identified in the current literature on this topic. Ultimately, this will improve individualized strategies for reducing orofacial pain and/or dysfunction in PD patients.
Topics: Facial Pain; Humans; Mastication; Parkinson Disease; Quality of Life; Temporomandibular Joint Disorders
PubMed: 36063442
DOI: 10.1002/ejp.2031 -
Quintessence International (Berlin,... Jul 2023Oral epitheliolysis or mucosal shedding is an infrequently described phenomenon characterized by epithelial desquamation, revealing mucosa of normal color and texture...
Oral epitheliolysis or mucosal shedding is an infrequently described phenomenon characterized by epithelial desquamation, revealing mucosa of normal color and texture underneath. The condition has a predilection for middle-aged females and primarily affects nonkeratinized oral tissues. Although some cases are idiopathic, certain oral hygiene products have been implicated as the culprit, and resolution of the condition documented with their discontinuation. Severity of desquamation and symptoms vary with frequency and duration of contact with the irritant and its concentration. A case is presented of a dramatic case of shedding oral mucosa in an elderly female, which appeared to be caused by habitual chewing of an aspirin-containing over-the-counter analgesic.
Topics: Aged; Female; Humans; Head; Mastication; Mouth Mucosa
PubMed: 37139952
DOI: 10.3290/j.qi.b4069169 -
Nihon Yakurigaku Zasshi. Folia... 2023Postprandial glucose concentration is dependent on the time of day and its concentration in the morning is lower than in the evening. The circadian rhythm of glucose... (Review)
Review
Postprandial glucose concentration is dependent on the time of day and its concentration in the morning is lower than in the evening. The circadian rhythm of glucose metabolism is regulated by the central circadian pacemaker in the suprachiasmatic nucleus (SCN). Both the SCN circadian clock and the pancreatic clock play important role in generating and maintaining the circadian rhythm of glucose metabolism. Also, short sleep duration and circadian misalignment are closely associated with a decrease in insulin sensitivity and an increase in type2 diabetes. Increased frequency of mastication and/or thorough chewing has been reported to alter the secretion of hormones related to appetite and energy metabolism. Furthermore, we have reported that the effect of mastication on postprandial glucose metabolism is dependent on the time of day and frequency of mastication. Morning mastication but not evening decreases postprandial blood glucose concentrations and increases insulin secretion at 30 min and so-called the insulinogenic index as a marker of early-phase β-cell function. This novel finding may aid in reducing the incidence of obesity and type 2 diabetes mellitus. This review covers the basic concept of the mammalian human circadian system, the underlying mechanism causing phase adjustment of the circadian rhythms in the SCN and peripheral organs, and the effect of eating behavior (e.g., chewing frequency) on the circadian rhythm of glucose metabolism.
Topics: Animals; Humans; Circadian Clocks; Circadian Rhythm; Diabetes Mellitus, Type 2; Glucose; Mastication
PubMed: 36858499
DOI: 10.1254/fpj.22105 -
The Journal of Prosthetic Dentistry Sep 2022Studies determining the main predictors of masticatory performance by using mixing ability tests are sparse.
STATEMENT OF PROBLEM
Studies determining the main predictors of masticatory performance by using mixing ability tests are sparse.
PURPOSE
The purpose of this clinical study was to identify potential determinants of masticatory performance assessed by analyzing a patient's masticatory ability using bicolored chewing gum and visual, quantitative, and interactive methods.
MATERIAL AND METHODS
Nondental participants attending healthcare centers were consecutively recruited in Granada, Spain. The inclusion criteria were older than18 years and resident in the coverage area of the reference healthcare centers for at least the previous 6 months. The participants were excluded if they had received dental treatment in the previous 6 months or they were unable to communicate. The masticatory performance was determined by using 2-colored chewing gum (Kiss 3 white and blue; Smint) that was masticated for a total of 20 strokes. The masticated gum was crushed between 2 transparent glass slides, creating a 1-mm-thick specimen that was subsequently scanned. The mixed-color area was calculated as a percentage by using Photoshop as described by Schimmel et al and designated as the standard method. In addition, all images made were analyzed by using the Web application the Chewing Performance Calculator. In addition, the masticated bolus was inspected visually, and mastication performance was classified as being poor, moderate, or good. Sociodemographic data, as well as data on behaviors, medical and nutritional status, health-related quality of life, saliva, and general oral health, were collected for all participants to identify the main determinants of masticatory performance.
RESULTS
One hundred thirty-seven participants were enrolled. The masticatory performance values obtained using both methods (standard method and Chewing Performance Calculator) were significantly greater for well masticated gum (P<.001), which had been visually classified as being poorly masticated (69.1% for standard method and 43.5% for Chewing Performance Calculator), moderately masticated (89.7% for standard method and 67.3% for Chewing Performance Calculator), and well masticated (97.3% for standard method and 80.3% for Chewing Performance Calculator). The bivariate analyses revealed that masticatory performance was significantly higher in younger people (<65 years) (P=.008), who also had a higher basal salivary flow rate (P<.001), were nondenture users (P=.002), and had more standing teeth and occlusal units (P<.001). However, the multiple regression analyses showed that the number of occlusal units was the only significant predictor of masticatory performance. In addition, the mean masticatory performance (95% confidence interval: 47.7% to 56.8%) was found to be greatly improved (by 1.2% to 2.2%), with each occlusal unit, in accordance with the Chewing Performance Calculator and between 0.8% and 1.8% according to the standard method; the basal masticatory performance was calculated as 72.1% to 81.2% (95% confidence interval).
CONCLUSIONS
The number of occlusal units is one of the main predictors of masticatory performance when a 2-color bolus is used to test mixing ability.
Topics: Chewing Gum; Color; Humans; Mastication; Oral Health; Quality of Life; Software
PubMed: 33597078
DOI: 10.1016/j.prosdent.2020.08.003 -
Journal of Morphology Feb 2023The evolution of mammals is characterized, amongst other developments, by an increasing relevance of effective food processing in form of an increasingly durable... (Review)
Review
The evolution of mammals is characterized, amongst other developments, by an increasing relevance of effective food processing in form of an increasingly durable dentition, complex occlusal surfaces, and transverse chewing movements. Some factors have received increasing attention for the facilitation of the latter, such as the configuration of the jaw joint, the chewing muscle arrangement and lever arms, or the reduction of interlocking cusps on the cheek teeth occlusal surface. By contrast, the constraining effect of the anterior dentition (incisors and canines) on transverse chewing motions, though known, has received less comprehensive attention. Here, we give examples of this constraint in extant mammals and outline a variety of morphological solutions to this constraint, including a reduction of the anterior dentition, special arrangements of canines and incisors, the nesting of the mandibular cheek teeth within the maxillary ones, and the use of different jaw positions for different dental functions (cropping vs. grinding). We suggest that hypselodont anterior canines or incisors in some taxa might represent a compensatory mechanism for self-induced wear during a grinding chewing motion. We propose that the diversity in anterior dentition among mammalian herbivores, and the evolutionary trend towards a reduction of the anterior dentition in many taxa, indicates that the constraining effect of the anterior dentition, which is rigidly linked to the cheek teeth by the osseous jaws, represents a relevant selective pressure in mammalian evolution.
Topics: Animals; Mastication; Mammals; Movement; Incisor; Musculoskeletal System
PubMed: 36645378
DOI: 10.1002/jmor.21554