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Journal of Oral Rehabilitation Aug 2022Individuals with impaired oral sensation report difficulty chewing, but little is known about the underlying changes to tongue and jaw kinematics. Methodological...
BACKGROUND
Individuals with impaired oral sensation report difficulty chewing, but little is known about the underlying changes to tongue and jaw kinematics. Methodological challenges impede the measurement of 3D tongue movement and its relationship to the gape cycle.
OBJECTIVE
The aim of this study was to quantify the impact of loss of oral somatosensation on feeding performance, 3D tongue kinematics and tongue-jaw coordination.
METHODOLOGY
XROMM (X-ray Reconstruction of Moving Morphology) was used to quantify 3D tongue and jaw kinematics during feeding in three rhesus macaques (Macaca mulatta) before and after an oral tactile nerve block. Feeding performance was measured using feeding sequence duration, number of manipulation cycles and swallow frequency. Coordination was measured using event- and correlation-based metrics of jaw pitch, anterior tongue length, width and roll.
RESULTS
In the absence of tactile sensation to the tongue and other oral structures, feeding performance decreased, and the fast open phase of the gape cycle became significantly longer, relative to the other phases (p < .05). The tongue made similar shapes in both the control and nerve block conditions, but the pattern of tongue-jaw coordination became significantly more variable after the block (p < .05).
CONCLUSION
Disruption of oral somatosensation impacts feeding performance by introducing variability into the typically tight pattern of tongue-jaw coordination.
Topics: Animals; Feeding Behavior; Jaw; Macaca mulatta; Mastication; Movement; Sensation; Tongue
PubMed: 35514258
DOI: 10.1111/joor.13336 -
International Dental Journal Jun 2022Elderly people with dementia, who are increasing at a rate comparable to the rate at which theelderly population is growing, are becoming a serious social problem in...
BACKGROUND
Elderly people with dementia, who are increasing at a rate comparable to the rate at which theelderly population is growing, are becoming a serious social problem in Korea. Therefore, the purpose of this study was to investigate the association between molar occlusal balance and cognitive function among Koreans aged 65 years and older.
METHODS
A total of 308 participants aged 65 years and older who attended a senior center were recruited for the study with their consent. The Korean version of the Mini-Mental State Examination (MMSE-DS) was used to assess cognitive function, and masticatory ability was measured according to the ability to chew food, the number of remaining teeth, and the self-perceived perceived masticatory function. Relative molar occlusal balance was measured using the T-scan Ⅲ system. All collected data were analysed using SPSS version 23.0.
RESULTS
There was a significant association between cognitive function and molar masticatory ability (P < .05). The participants with relative molar occlusal balance had a higher MMSE-DS score when compared to those with relative incision occlusal balance, adjusted for sociodemographic factors and number of remaining teeth, subjective masticatory ability, chewing ability, occlusion time, and denture use. Cognitive function was higher when relative molar occlusion was greater compared to anterior occlusion in anterior-posterior teeth balance.
CONCLUSIONS
Cognitive function in elderly people was higher when the relative molar occlusal balance was greater. Mastication with posterior teeth may have a more important effect on stimulation of cognitive function. Therefore, oral health care focusing on maintenance of molar teeth may be crucial for elderly persons.
Topics: Aged; Cognition; Dental Occlusion; Humans; Mastication; Molar; Republic of Korea
PubMed: 34376281
DOI: 10.1016/j.identj.2021.05.011 -
CoDAS 2018Purpose Investigate and measure the effects of electrostimulation on the orofacial musculature and on the chewing, breathing and swallowing functions of individuals with...
Purpose Investigate and measure the effects of electrostimulation on the orofacial musculature and on the chewing, breathing and swallowing functions of individuals with Down syndrome. Methods Study participants were 16 individuals with Down syndrome (six males and 10 females) from an institutional extension project aged nine to 25 years. Speech-language pathology assessment was performed using the protocol of Orofacial Myofunctional Evaluation with Scores (OMES) pre- and post-intervention. This protocol comprised eight weekly electrostimulation sessions. Functional Electrical Stimulation (FES) current was used at a frequency of 10Hz in warm-up and 30Hz in application, intermittent stimulation (cycling pulses) with ON-time of 5s and OFF-time of 10s common to both stages, and pulse width of 200μs in warm-up and 250μs in application. Results Significant differences were observed between pre- and post-application of FES regarding cheek appearance (flaccidity and arching), tongue mobility (right and left laterality), and musculature behavior during performance of functions of the stomatognathic system: respiration, deglutition (lip behavior), and mastication (bite and trituration). Conclusion Effects of electrostimulation associated with masticatory training of the masseter muscles were statistically identified, with functional gains in chewing, breathing and swallowing performance in individuals with Down syndrome.
Topics: Adolescent; Adult; Child; Deglutition; Down Syndrome; Electric Stimulation Therapy; Electromyography; Female; Humans; Longitudinal Studies; Male; Masseter Muscle; Mastication; Stomatognathic System; Tongue; Young Adult
PubMed: 29846393
DOI: 10.1590/2317-1782/20182017074 -
Scientific Reports Apr 2019We examined how attention alters chewing and swallowing behaviors. Twenty-one healthy volunteers were asked to freely eat 8 g of steamed rice in three separate trials,...
We examined how attention alters chewing and swallowing behaviors. Twenty-one healthy volunteers were asked to freely eat 8 g of steamed rice in three separate trials, and we obtained the average number of chewing cycles (N) and chewing duration (T) prior to the first swallow in each trial. We also conducted an N-limited test, in which participants chewed the food while independently counting the number of chewing cycles and swallowed the food when they reached N, and a T-limited test, in which they chewed the food for T sec and then swallowed. We recorded electromyograms (EMGs) from masseter and suprahyoid muscles and collected videoendoscopic images. In the N-limited test, chewing speed decreased, masseter muscle activity (area under the curve of the rectified EMG burst) per cycle increased, and suprahyoid muscle activity per cycle decreased. In the T-limited test, the chewing speed increased, muscle activities per cycle decreased, and the number of cycles increased. The occurrence frequency of bolus propulsion into the pharynx before swallowing was smaller in the N- and T-limited tests than in the free chewing test. Further, the whiteout time was longer in the T-limited test than in the free chewing test. Attentional chewing changes not only chewing but also swallowing behavior.
Topics: Adult; Attention; Deglutition; Female; Healthy Volunteers; Humans; Male; Mastication
PubMed: 30979956
DOI: 10.1038/s41598-019-42422-4 -
Physiology & Behavior Nov 2020Exposure to sensory food cues such as smell, vision, taste and/or texture may trigger anticipatory physiological responses such as salivation, participating on adequate...
Exposure to sensory food cues such as smell, vision, taste and/or texture may trigger anticipatory physiological responses such as salivation, participating on adequate metabolism of the signaled food. However, the individual contribution of each sensory modality as well as the impact of particular food products on salivation and salivary composition remains unclear. Therefore, by systematically varying sensory modalities and nutrient content of food stimuli, we investigated their effect on saliva secretion, α-amylase activity and other salivary characteristics (pH level, buffering capacity, MUC5B concentration, and total protein content). Over 3 sessions, 46 normal-weight healthy participants were exposed to 12 conditions, consisting of 4 levels of sensory stimulation (odor, odor + vision, odor + vision + taste, and odor + vision + taste + mastication) and 3 types of stimuli (bread, high-in-starch; cucumber, low-in-starch; and parafilm as non-food control) during which saliva was collected. Linear mixed models showed a significant increase in salivation with increasing levels of sensory stimulation. α-amylase secretion rate increased upon the highest level of stimulation, which involved mastication, compared to odor and odor + visual level of stimulation. Other salivary characteristics varied with the level of sensory stimulation, which might be related to the total volume of salivation. The type of stimuli did not influence the saliva composition (α-amylase concentration nor other salivary components). Our findings indicate that cumulative sensory information, rather than specific (food) product, play a vital role in anticipatory salivary responses.
Topics: Cues; Food; Humans; Mastication; Saliva; Salivation; Taste
PubMed: 32750433
DOI: 10.1016/j.physbeh.2020.113116 -
Supportive Care in Cancer : Official... Mar 2020The purpose of this study was to observe the impact of oral oncological treatment, including the recovery of several tongue functions (force, mobility, and sensory...
PURPOSE
The purpose of this study was to observe the impact of oral oncological treatment, including the recovery of several tongue functions (force, mobility, and sensory functions), and to determine the influence of these functions on masticatory performance.
MATERIALS AND METHODS
Masticatory performance and tongue force, mobility, and sensory functions were determined in 123 patients with oral cavity cancer. The assessments were performed 4 weeks before treatment and 4 to 6 weeks, 6 months, 1 year, and 5 years after treatment. Generalized estimation equations and mixed model analyses were performed, correcting for previously identified factors in the same population.
RESULTS
A significant deterioration in tongue mobility and sensory function was observed in patients with mandible and tongue and/or floor-of-mouth tumors. Better tongue force and sensory function (thermal and tactile) positively influenced masticatory performance, and this effect was stronger where fewer occlusal units were present. The effect of both the tongue force and maximum bite force was weaker in dentate patients in comparison with patients with full dentures. A web-based application was developed to enable readers to explore our results and provide insight into the coherence between the found factors in the mixed model.
CONCLUSIONS
Tongue function deteriorates after oral oncological treatment, without statistically significant recovery. Adequate bite and tongue forces are especially important for patients with a poor prosthetic state. Patients with sensory tongue function deficits especially benefit from the presence of more occluding pairs.
Topics: Aged; Bite Force; Female; Humans; Male; Mastication; Middle Aged; Mouth Neoplasms; Prospective Studies; Tongue
PubMed: 31273502
DOI: 10.1007/s00520-019-04913-y -
Brain Research Apr 2021Vagus nerve stimulation (VNS) paired with motor rehabilitation enhances recovery of function after neurological injury in rats and humans. This effect is ascribed to...
Vagus nerve stimulation (VNS) paired with motor rehabilitation enhances recovery of function after neurological injury in rats and humans. This effect is ascribed to VNS-dependent facilitation of plasticity in motor networks. Previous studies document an inverted-U relationship between VNS intensity and cortical plasticity, such that moderate intensities increase plasticity, while low or high intensity VNS does not. We tested the interaction of moderate and high intensity VNS trains to probe the mechanisms that may underlie VNS-dependent plasticity. Rats performed a behavioral task where VNS was paired with jaw movement during chewing. For five days, subjects received 100 pairings of moderate intensity VNS (Standard VNS), 100 pairings alternating between moderate and high intensity VNS (Interleaved VNS), or 50 pairings of moderate intensity VNS (Short VNS) approximately every 8 s. After the final behavioral session, intracortical microstimulation (ICMS) was used to evaluate movement representations in motor cortex. 100 pairings of moderate intensity VNS enhanced motor cortex plasticity. Replacing half of moderate intensity stimulation with high intensity VNS blocked this enhancement of plasticity. Removing high intensity stimulation, leaving only 50 pairings of moderate intensity VNS, reinstated plasticity. These results demonstrate that there is a period for at least 8 s after high intensity stimulation in which moderate intensity VNS is not able to engage mechanisms required for synaptic reorganization. More importantly, this study demonstrates that changes in stimulation parameters are a critical determinant of the magnitude of plasticity and likely the efficacy of VNS-enhanced recovery.
Topics: Animals; Female; Mastication; Motor Cortex; Movement; Neuronal Plasticity; Rats, Sprague-Dawley; Recovery of Function; Vagus Nerve Stimulation; Rats
PubMed: 33539792
DOI: 10.1016/j.brainres.2021.147332 -
Sensors (Basel, Switzerland) Jan 2020We present an eating detection algorithm for wearable sensors based on first detecting chewing cycles and subsequently estimating eating phases. We term the...
We present an eating detection algorithm for wearable sensors based on first detecting chewing cycles and subsequently estimating eating phases. We term the corresponding algorithm class as a bottom-up approach. We evaluated the algorithm using electromyographic (EMG) recordings from diet-monitoring eyeglasses in free-living and compared the bottom-up approach against two top-down algorithms. We show that the F1 score was no longer the primary relevant evaluation metric when retrieval rates exceeded approx. 90%. Instead, detection timing errors provided more important insight into detection performance. In 122 hours of free-living EMG data from 10 participants, a total of 44 eating occasions were detected, with a maximum F1 score of 99.2%. Average detection timing errors of the bottom-up algorithm were 2.4 ± 0.4 s and 4.3 ± 0.4 s for the start and end of eating occasions, respectively. Our bottom-up algorithm has the potential to work with different wearable sensors that provide chewing cycle data. We suggest that the research community report timing errors (e.g., using the metrics described in this work).
Topics: Adult; Algorithms; Diet; Electromyography; Female; Humans; Male; Mastication; Monitoring, Physiologic; Signal Processing, Computer-Assisted; Smart Glasses; Temporal Muscle
PubMed: 31968532
DOI: 10.3390/s20020557 -
Journal of Dentistry Oct 2021This study aimed to subjectively and objectively assess masticatory function and identify related factors in older adults.
OBJECTIVES
This study aimed to subjectively and objectively assess masticatory function and identify related factors in older adults.
METHODS
From July 2017 to September 2018, we enrolled 115 healthy participants aged between 65 and 86 years. They underwent oral examination, and their stimulated salivary secretion rate and masseter muscle tone and biomechanical properties were assessed. Masticatory performance with two-colored chewing wax was objectively evaluated using the mixing ability index (MAI). Key food intake ability (KFIA) was subjectively assessed using a questionnaire.
RESULTS
The MAI score was significantly associated with the number of remaining teeth (r = 0.524, p < 0.001) and the tone (r = -0.222, p = 0.017), elasticity (r = -0.242, p = 0.009), and dynamic stiffness (r = -0.265, p = 0.004) of the masseter muscles. In contrast, the KFIA score was only significantly associated with the number of remaining teeth (r = 0.450, p < 0.001). A weak association between the MAI and KFIA scores was observed (r = 0.304, p = 0.001).
CONCLUSIONS
A combination of objective and subjective methods should be used to accurately assess masticatory function in older adults. In addition to physical factors such as the number of remaining teeth, properties of the masticatory muscles should be evaluated to improve the masticatory function of older adults.
CLINICAL SIGNIFICANCE
In addition to dental problems, various maxillofacial and oral factors must be considered when establishing management strategies for the improvement of masticatory function in older adults.
Topics: Aged; Aged, 80 and over; Humans; Mastication; Surveys and Questionnaires; Tooth
PubMed: 34425173
DOI: 10.1016/j.jdent.2021.103787 -
Philosophical Transactions of the Royal... Dec 2023Understanding of tongue deformations during mammalian mastication is limited, but has benefited from recent developments in multiplanar imaging technology. Here, we...
Understanding of tongue deformations during mammalian mastication is limited, but has benefited from recent developments in multiplanar imaging technology. Here, we demonstrate how a standardized radiopaque marker implant configuration and biplanar fluoroscopy can quantify three-dimensional shape changes during chewing in pigs. Transverse and sagittal components of the three-dimensional angle between markers enable characterizing deformations in anatomically relevant directions. The transverse component illustrates bending to the left or to the right, which can occur symmetrically or asymmetrically, the latter sometimes indicating regional widening. The sagittal component reflects 'arching' or convex deformations in the dorsoventral dimension symmetrically or asymmetrically, the latter characteristic of twisting. Trends are detected in both the transverse and sagittal planes, and combinations thereof, to modify tongue shape in complex deformations. Both the transverse and sagittal components were also measured at key jaw and tongue positions, demonstrating variability particularly with respect to maximum and minimum gape. This highlights the fact that unlike tongue position, tongue deformations are more independent of jaw position, likely in response to the ever-changing bolus shape and position. From a methodological perspective, our study showcases advantages of a repeatable three-marker implant configuration suitable for animals of different sizes and highlights considerations for different implant patterns. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.
Topics: Swine; Animals; Mastication; Jaw; Tongue; Tooth; Mammals
PubMed: 37839450
DOI: 10.1098/rstb.2022.0555