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The Journal of Experimental Biology Apr 2021Mastication and drinking are rhythmic and cyclic oral behaviors that require interactions between the tongue, jaw and a food or liquid bolus, respectively. During...
Mastication and drinking are rhythmic and cyclic oral behaviors that require interactions between the tongue, jaw and a food or liquid bolus, respectively. During mastication, the tongue transports and positions the bolus for breakdown between the teeth. During drinking, the tongue aids in ingestion and then transports the bolus to the oropharynx. The objective of this study was to compare jaw and tongue kinematics during chewing and drinking in pigs. We hypothesized there would be differences in jaw gape cycle dynamics and tongue protraction-retraction between behaviors. Mastication cycles had an extended slow-close phase, reflecting tooth-food-tooth contact, whereas drinking cycles had an extended slow-open phase, corresponding to tongue protrusion into the liquid. Compared with chewing, drinking jaw movements were of lower magnitude for all degrees of freedom examined (jaw protraction, yaw and pitch), and were bilaterally symmetrical with virtually no yaw. The magnitude of tongue protraction-retraction (Txt), relative to a mandibular coordinate system, was greater during mastication than during drinking, but there were minimal differences in the timing of maximum and minimum Txt relative to the jaw gape cycle between behaviors. However, during drinking, the tongue tip is often located outside the oral cavity for the entire cycle, leading to differences between behaviors in the timing of anterior marker maximum Txt. This demonstrates that there is variation in tongue-jaw coordination between behaviors. These results show that jaw and tongue movements vary significantly between mastication and drinking, which hints at differences in the central control of these behaviors.
Topics: Animals; Biomechanical Phenomena; Drinking; Jaw; Mastication; Movement; Swine; Tongue
PubMed: 33674496
DOI: 10.1242/jeb.239509 -
Scientific Reports Aug 2022Bulk-fill composites enable timesaving and less technical-sensitive application of restorations. This study investigated and compared the marginal integrity of classical...
Bulk-fill composites enable timesaving and less technical-sensitive application of restorations. This study investigated and compared the marginal integrity of classical and bulk-fill composite restorations in primary and permanent molars before and after thermo-mechanical loading (TML). Two Class II cavities were prepared in each of 20 primary and 20 permanent molars. The molars were randomised in four groups for each molar type. Groups 1 and 5 were restored with a high-viscous bulk-fill composite (Tetric PowerFill), groups 2 and 6 were restored with a flowable bulk-fill composite (Tetric PowerFlow), groups 3 and 7 were restored with a high-viscous classical composite (Tetric Prime), and groups 4 and 8 were restored with a flowable classical composite (Tetric EvoFlow). In permanent molars, the flowable composites were covered with a 2-mm layer of high-viscous composite (groups 6 and 8). The restorations were subjected to TML in a custom-made chewing machine (5-50 °C, 2 min dwelling time, × 1000; 400 ,000 loading cycles, 1.7 Hz, 49 N), and quantitative marginal analysis was conducted using scanning electron microscopy. Marginal integrity of each restoration was calculated as a percentage of continuous margins before and after TML. The tested high-viscous bulk-fill restoration showed similarly high marginal integrity in primary and permanent molars as the classical restoration. The tested flowable bulk-fill restoration showed the lowest marginal integrity compared to all other restorations after TML. In contrast to flowable bulk-fill restorations, high-viscous bulk-fill restorations show similar marginal integrity as classical hybrid composite restorations after TML, in both primary and permanent molars.
Topics: Composite Resins; Dental Restoration, Permanent; Mastication; Materials Testing; Microscopy, Electron, Scanning; Molar; Viscosity
PubMed: 35953552
DOI: 10.1038/s41598-022-18126-7 -
Zhejiang Da Xue Xue Bao. Yi Xue Ban =... Jun 2023Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and... (Review)
Review
Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.
Topics: Humans; Mastication; Temporomandibular Joint; Temporomandibular Joint Disorders; Mandible
PubMed: 37476950
DOI: 10.3724/zdxbyxb-2023-0066 -
Scientific Reports Jan 2024The first step in any dietary monitoring system is the automatic detection of eating episodes. To detect eating episodes, either sensor data or images can be used, and...
The first step in any dietary monitoring system is the automatic detection of eating episodes. To detect eating episodes, either sensor data or images can be used, and either method can result in false-positive detection. This study aims to reduce the number of false positives in the detection of eating episodes by a wearable sensor, Automatic Ingestion Monitor v2 (AIM-2). Thirty participants wore the AIM-2 for two days each (pseudo-free-living and free-living). The eating episodes were detected by three methods: (1) recognition of solid foods and beverages in images captured by AIM-2; (2) recognition of chewing from the AIM-2 accelerometer sensor; and (3) hierarchical classification to combine confidence scores from image and accelerometer classifiers. The integration of image- and sensor-based methods achieved 94.59% sensitivity, 70.47% precision, and 80.77% F1-score in the free-living environment, which is significantly better than either of the original methods (8% higher sensitivity). The proposed method successfully reduces the number of false positives in the detection of eating episodes.
Topics: Humans; Mastication; Monitoring, Physiologic; Diet; Recognition, Psychology; Mental Processes
PubMed: 38238423
DOI: 10.1038/s41598-024-51687-3 -
Journal of Dentistry Feb 2023To give an overview of the evidence on the associations between oral condition factors and masticatory performance of adults, and to evaluate the direction and level of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To give an overview of the evidence on the associations between oral condition factors and masticatory performance of adults, and to evaluate the direction and level of the associations.
DATA/SOURCES
Medline (PubMed), Embase (Ovid) and CINAHL Plus (EBSCOhost) were searched up to May 2022 for cross-sectional studies on oral conditions and masticatory performance in adults. Methodological quality of the included studies was independently evaluated based on the Joanna Briggs Institute critical appraisal checklist for analytical cross-sectional studies. Data on the associations between oral condition factors and masticatory performance were extracted. Meta-analysis was conducted on correlation coefficients.
STUDY SELECTION
Of the 8,035 records identified, 97 articles (88 studies) were included in the qualitative synthesis, and 18 studies were included in the meta-analyses. Among the oral condition factors that had associations with masticatory performance, the number of natural/remaining teeth or functional tooth pairs was reported by the largest number of studies, followed by perioral muscle status, dental prosthetic status, oral moisture status and periodontal status. Results of the meta-analyses showed that the positive association with the number of natural/remaining teeth was the strongest (pooled correlation coefficient: 0.51, 95%CI: 0.48 to 0.54), followed by the number of functional tooth pairs, maximum tongue force/pressure, while the association with the oral moisture status was the weakest.
CONCLUSIONS
Number of natural/remaining teeth and functional tooth pairs, perioral muscle status, oral moisture status, dental prosthetic status and periodontal status are the main oral condition factors influencing masticatory performance. Based on the limited evidence available, among these factors, the number of natural/remaining teeth has the strongest positive association, with a very low quality of evidence.
CLINICAL SIGNIFICANCE
This study provides valuable information on the oral condition factors associated with masticatory performance, which would be important for policymakers and clinical practitioners when deciding on the strategies for improving the masticatory performance of adults. This review highlights the need for standardization of measures and classifications of masticatory performance and oral conditions.
REGISTRATION
PROSPERO (registration number: CRD42021256824).
Topics: Humans; Adult; Bite Force; Mastication; Cross-Sectional Studies; Mouth, Edentulous
PubMed: 36563840
DOI: 10.1016/j.jdent.2022.104395 -
PloS One 2023Monitoring the feeding and ruminating behaviour of ruminants can be used to assess their health and welfare. The MSR-jaw movement recording system (JAM-R) can...
Monitoring the feeding and ruminating behaviour of ruminants can be used to assess their health and welfare. The MSR-jaw movement recording system (JAM-R) can automatically record the jaw movements of ruminants. The associated software Viewer2 was developed to classify these recordings in adult cattle and calculate the duration and number of mastications of feeding and ruminating. The purpose of this study was to evaluate the performance of Viewer2 in classifying the behaviour of sheep and goats and assessing their feeding and ruminating. The feeding and ruminating behaviour of ten sheep and ten goats on pasture (observed live) and of five sheep and five goats in the barn (observed by video) were compared with Viewer2 behaviour classifications. To assess the technical and welfare issues of the JAM-R, its application was tested in a feeding experiment with 24 h monitoring of the feeding behaviours of 24 sheep and 24 goats. Viewer2 worked equally well on both species. The mean (95% confidence interval) performance of Viewer2 was at a good level for feeding (accuracy: 0.8-1.0; sensitivity: 0.9-1.0; specificity: 0.6-0.9; precision: 0.7-0.9) and ruminating (accuracy: 0.8-0.9; sensitivity: 0.6-0.8; specificity: 0.8-1.0; precision: 0.9-1.0) compared with human observations, with minor differences between the conditions on pasture and in the barn. The performance improved when recording frequency was increased from 10 Hz to 20 Hz. Applying the JAM-R in a feeding experiment, 71% of the recordings executed were defined as technically error-free and produced plausible values for feeding behaviours. In conclusion, according to the values of accuracy, sensitivity, specificity and precision, the presented JAM-R system with Viewer2 is a reliable and applicable technology for automatic recording of feeding and ruminating behaviour of sheep and goats on pasture and in the barn.
Topics: Humans; Sheep; Animals; Cattle; Goats; Feeding Behavior; Eating; Ruminants; Mastication
PubMed: 37200299
DOI: 10.1371/journal.pone.0285933 -
Journal of Oral Rehabilitation Dec 2022Speaking depends on refined control of jaw opening and closing movements. The medial pterygoid muscle (MPT), involved in jaw closing, and the lateral pterygoid muscle...
BACKGROUND
Speaking depends on refined control of jaw opening and closing movements. The medial pterygoid muscle (MPT), involved in jaw closing, and the lateral pterygoid muscle (LPT), involved in jaw opening, are two key mandibular muscles in mastication and are likely to be recruited for controlled movements in speech.
OBJECTIVES
Three hypotheses were investigated, that during speech the MPT and LPT: (1) were both active, (2) but exhibited different patterns of activity, (3) which fluctuated with the vowels and consonants in speech.
METHODS
Intramuscular EMG recordings were made from the right inferior head of the LPT and/or the right MPT in five participants during production of 40 target nonsense words (NWs) consisting of three syllables in the form /V C V C ə/ (V = vowel; C = consonant; ə = unstressed, reduced vowel), spoken by each participant 10 times per NW; analysis focussed on the target syllable, C V .
RESULTS
Both MPT and LPT exhibited robust increases in EMG activity during utterance of most NWs, relative to rest. Peak LPT activation was time-locked to the final part of the target consonant (C ) interval when the jaw begins opening for the target vowel (V ), whereas peak MPT activation occurred around the temporal midpoint of V , when the jaw begins closing for C . EMG amplitude peaks differed in magnitude between "high" vowels, i.e., for which the tongue/jaw are high (e.g., in SEEK), and "low" vowels, i.e., for which the tongue/jaw are low (e.g., in SOCK).
CONCLUSIONS
These novel findings suggest a key role for the LPT and MPT in the fine control of speech production. They imply that speech may impose major synergistic demands on the activities of the MPT and the LPT, and thereby provide insights into the possible interactions between speech activities and orofacial activities (e.g. mastication) and conditions (e.g. Temporomandibular Disorders) that involve the masticatory muscles.
Topics: Humans; Pterygoid Muscles; Speech; Electromyography; Masticatory Muscles; Mastication; Movement
PubMed: 36165884
DOI: 10.1111/joor.13377 -
Physiology & Behavior May 2019The use of smartphones during meals may possibly influence the number of ingested calories. We evaluated the influence of smartphones' distraction during eating on...
The use of smartphones during meals may possibly influence the number of ingested calories. We evaluated the influence of smartphones' distraction during eating on caloric intake. Physical (masticatory parameters, sex and body mass index - BMI); environmental (with or without distraction) and psychological (stress levels) variables were evaluated as confounding factors. Sixty-two adults were recruited for experimental snack tests performed on four different days. At baseline, we evaluated masticatory performance, swallowing threshold, masticatory frequency and body mass index (BMI). In the following three sessions, volunteers were presented a snack test in which participants ate under three experimental conditions: no distraction, using their smartphones, or reading a printed text. At the end of each session, total and nutritional compound stratified caloric intake was measured. Three-way mixed model ANOVA was used to test the effect of experimental condition on the total, carbohydrate and lipid caloric intakes. Hierarchical multiple linear regression models were used to estimate the influence of confounding factors on the total caloric intake. We found an effect of the condition (no distraction, smartphone or reading) on the total caloric (p = .007) and lipid intake (p = .002). When eating without distraction, the mean caloric intake was 535 (±164) kcal, in comparison to 591 (±203) kcal using smartphone (p = .05) and 622 (±226) kcal (p = .002) reading a text (no significant difference between distracters). Eating with distracters increased approximately 15% caloric ingestion. An interaction condition*sex effect was observed on lipid intake (p = .020). Energy intake was found to be dependent on sex and age, in which older men ingested more calories. Smartphone use during a meal increased caloric and lipid intake, depending on sex and age in young adults with complete dentition.
Topics: Adolescent; Adult; Aging; Body Mass Index; Deglutition; Dietary Carbohydrates; Dietary Fats; Eating; Energy Intake; Female; Humans; Male; Mastication; Reading; Sex Characteristics; Smartphone; Snacks; Stress, Psychological; Young Adult
PubMed: 30776379
DOI: 10.1016/j.physbeh.2019.02.021 -
Jornal de Pediatria 2023The objective of this study was to analyze masticatory characteristics in children from 7 to 10 years, and to compare these characteristics among normal weight,...
OBJECTIVE
The objective of this study was to analyze masticatory characteristics in children from 7 to 10 years, and to compare these characteristics among normal weight, overweight and obese children.
METHODS
This is a cross-sectional study, conducted in northeast Brazil, with a sample of 160 children, aged 7 to 10 years. The authors evaluated: nutritional and dental status; food intake; masticatory parameters and orofacial myofunctional characteristics. The children were divided according to nutritional status into normal weight (n = 101), overweight (n = 33) and obesity (n = 26) groups.
RESULTS
The results showed that Obese children had a larger bite size (g) (median = 6.0, Q1-Q3 = 4.0-9.0, p = 0.049) and performed fewer masticatory sequences (median = 3.0, Q1-Q3 = 2.0-3.2, p = 0.024) than children with normal weight (median = 5.0, Q1-Q3 = 4.0-7.0; median = 4.0, Q1-Q3 = 3.0-5.0). Furthermore, obese children finished feeding in a shorter time (s) (median = 62.5, Q1-Q3 = 50.5-70.0, p = 0.039) than normal weight children (median = 66.0, Q1-Q3 = 56.5-78.0) and overweight children (median = 66.0, Q1-Q3 = 58.0-81.5).
CONCLUSIONS
The present results suggest that obese children present changes in mastication, evidenced by larger bite-size, performing fewer masticatory sequences and rapid mastication, which may contribute to increased food consumption and the development of excess weight.
Topics: Humans; Child; Overweight; Mastication; Cross-Sectional Studies; Pediatric Obesity; Weight Gain
PubMed: 36113564
DOI: 10.1016/j.jped.2022.07.008 -
Journal of Oral Science 2023To clarify the presence or absence of differences in path pattern and movement during mastication between the habitual and non-habitual chewing sides.
PURPOSE
To clarify the presence or absence of differences in path pattern and movement during mastication between the habitual and non-habitual chewing sides.
METHODS
Participants were 225 healthy adults with natural dentition. Mandibular movement while chewing gummy jelly on each side was recorded, and masticatory path pattern was classified into five types (one normal and four abnormal). The frequency of each pattern was measured and compared between chewing sides. The amount, rhythm, velocity, and stability of movement and masticatory performance were measured and compared between chewing sides.
RESULTS
A normal pattern was observed on the habitual chewing side in 84.4% of participants. There was a significant difference between chewing sides in masticatory path pattern (χ = 35.971, P < 0.001). Values of parameters regarding the amount and velocity of movement and masticatory performance were significantly higher on the habitual chewing side. Values of parameters regarding rhythm and stability of movement were significantly lower on the habitual chewing side.
CONCLUSION
The present findings of functional differences between chewing sides in terms of path pattern and movement during mastication suggest that these factors should be analyzed on the habitual chewing side.
Topics: Adult; Humans; Mastication; Mandible; Food; Mouth, Edentulous; Movement
PubMed: 37394545
DOI: 10.2334/josnusd.23-0101