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Scientific Reports Nov 2020The biomechanical and adaptive significance of variation in craniodental and mandibular morphology in fossil hominins is not always clear, at least in part because of...
The biomechanical and adaptive significance of variation in craniodental and mandibular morphology in fossil hominins is not always clear, at least in part because of a poor understanding of how different feeding behaviors impact feeding system design (form-function relationships). While laboratory studies suggest that ingestive behaviors produce variable loading, stress, and strain regimes in the cranium and mandible, understanding the relative importance of these behaviors for feeding system design requires data on their use in wild populations. Here we assess the frequencies and durations of manual, ingestive, and masticatory behaviors from more than 1400 observations of feeding behaviors video-recorded in a wild population of bearded capuchins (Sapajus libidinosus) at Fazenda Boa Vista in Piauí, Brazil. Our results suggest that ingestive behaviors in wild Sapajus libidinosus were used for a range of food material properties and typically performed using the anterior dentition. Coupled with previous laboratory work indicating that ingestive behaviors are associated with higher mandibular strain magnitudes than mastication, these results suggest that ingestive behaviors may play an important role in craniodental and mandibular design in capuchins and may be reflected in robust adaptations in fossil hominins.
Topics: Animals; Animals, Wild; Anthropology, Physical; Biological Evolution; Biomechanical Phenomena; Cebinae; Eating; Feeding Behavior; Female; Male; Mandible; Mastication
PubMed: 33257755
DOI: 10.1038/s41598-020-77797-2 -
Behavioural Processes May 2024In this short communication, we describe chewing behaviour in sows with no apparent edible substrate in their mouth as a potential social behaviour. Chewing in sows...
In this short communication, we describe chewing behaviour in sows with no apparent edible substrate in their mouth as a potential social behaviour. Chewing in sows during interaction with unfamiliar sows was unexpectedly observed in a study assessing social abilities and damaging behaviours in group-housed dry sows. Such chewing was observed frequently and performed by almost all sows. To our knowledge, this behaviour has not been described previously in a social context in pigs, but rather as an oral stereotypic behaviour related to chronic hunger. We describe the behaviour in its social context and speculate on reasons for its occurrence in that context.
Topics: Animals; Female; Mastication; Swine; Social Behavior; Behavior, Animal
PubMed: 38679342
DOI: 10.1016/j.beproc.2024.105042 -
Journal of Population Therapeutics and... 2022To study and systematize the complaints of patients with removable prostheses, paying attention to the clinical manifestation of the torus and its sensitivity, and to...
AIM
To study and systematize the complaints of patients with removable prostheses, paying attention to the clinical manifestation of the torus and its sensitivity, and to determine the effectiveness of the use of two-layer bases in removable prosthetics.
METHODS
In the clinic of orthopedic dentistry, 104 people were examined and received orthopedic treatment, including 37 patients in the comparison group. The main number of patients up to 55.3, complained of poor fixation and violation of the chewing process. In order to improve the functional efficiency of the removable prosthesis, two-layer bases using soft linings, Gossil (Russia), Furji (Japan), and Mucopren (Germany), are proposed. Clinical and laboratory studies were conducted (Estesmary, gattingeri, physico-mechanical studies of soft linings). The effectiveness of using soft pads in removable prosthetics is shown. The conducted research allowed creating a clinical classification of the torus depending on the pain sensitivity of the oral mucosa-type I-painless torus, type II-moderately painful, and type III-painful when touched. The features of the technology for manufacturing two-layer bases for type II and type III of torus are recommended.
RESULTS
It was found that 47.9% of patients in the comparison group and 55.3% of those examined in the main group complained about impaired chewing and poor fixation of dentures on the upper and lower jaws, depending on the condition of oral tissues. The patients did not always objectively assess the condition of their dentures. Patients complained about lack of stabilization, poor-quality dentures, and the need to replace the old denture with a new one in 13.8% of cases in the control group and 31.9% in the main group of patients examined.
CONCLUSION
In the case of removable denture wearers with a total lack of teeth, there were 55.3% complaints of chewing disorders and poor fixation of dentures, and in the case of partially removable denture wearers, the greatest number of complaints of clasp fixation disorders were found in 42.1% of cases. Physico-mechanical study of soft linings from different countries, Gossil (Russia), Fuji (Japan), Mukopren (Germany), showed their effectiveness and the possibility of their use orthopedic dentistry.
Topics: Denture, Partial; Denture, Partial, Removable; Humans; Mastication
PubMed: 36196942
DOI: 10.47750/jptcp.2022.939 -
Journal of Dentistry Jan 2021This study aims to investigate the impact of occluding pairs (OPs) on chewing strokes, chewing time, mealtime duration, and bite force in an aging population.
OBJECTIVES
This study aims to investigate the impact of occluding pairs (OPs) on chewing strokes, chewing time, mealtime duration, and bite force in an aging population.
METHODS
The 100 participants included 52 women and 48 men with average age of 71.2 years. The subjects were restricted to those who can eat what they wanted and had no temporomandibular joint disorder (TMD) and dysphagia history; their OPs were counted in the posterior occlusal support zone in accordance with the Eichner classification. Free habitual mastication of a cornstarch cookie was analyzed by recording the number of chewing strokes and the amount of time needed for complete mastication. Strokes were counted by considering the opening and closing mandibular movements. Mealtime was defined as the time spent to finish a lunchbox and accomplish swallowing. Bite force was estimated with a T-Scan III®. A linear regression analysis was used to evaluate the impact of the OPs on the chewing strokes, chewing time, mealtime duration, and bite force.
RESULTS
In this study, 76% of the participants had 4 OPs and 12% participants had 3 OPs. Increasing the OPs significantly shortened the chewing time and mealtime duration (P = 0.02). The mealtime duration did not notably affect the chewing time (P = 0.237). There was significant association between OPs and bite force (P < 0.0001).
CONCLUSIONS
In elderly, increasing OPs significantly raised the bite force and shortened the chewing time and strokes. More OPs might be the key to maintain good chewing function.
CLINICAL SIGNIFICANCE
Among the elderly, increasing OPs significantly raised the bite force and shortened the chewing time and mealtime duration. To provide better chewing function, good oral hygiene is important to maintain as many OPs as possible; how to gain more OPs is essential concern in the prosthodontic treatment plan making.
Topics: Aged; Bite Force; Female; Humans; Male; Mandible; Mastication; Temporomandibular Joint Disorders
PubMed: 33212204
DOI: 10.1016/j.jdent.2020.103511 -
Clinical and Experimental Dental... Dec 2021Lip-seal strength, which represents the muscle strength of the lips, appears to chiefly contribute to mastication and pronunciation. However, the functional...
OBJECTIVES
Lip-seal strength, which represents the muscle strength of the lips, appears to chiefly contribute to mastication and pronunciation. However, the functional characteristics of lip-seal strength in adults are still undefined. The present study aimed to understand not only the distribution of lip-seal strength in adult men and women but also the effect of age on this strength and identify oral motor functions correlated with lip-seal strength.
MATERIALS AND METHODS
The subjects included 339 participants (men: 170, age 39.2 ± 18.2 years; women: 169, age 43.1 ± 19.7 years). Oral motor function was evaluated for lip-seal strength, oral diadochokinesis (ODK), tongue pressure, occlusal force, and masticatory performance. Statistical analyses included the Shapiro-Wilk, Mann-Whitney U, and Jonckheere-Terpstra tests, in addition to the Spearman's correlation analysis and curvilinear regression analysis.
RESULTS
Lip-seal strength did not have a normal distribution (p < 0.001). The mean ± standard deviation and median (first quartile, third quartile) of lip-seal strength were 11.2 ± 3.4 and 10.9 (8.7, 13.2)N for the whole sample, 12.3 ± 3.4 and 11.9 (9.4, 14.4)N for men, and 10.2 ± 3.0 and 9.9 (8.0, 12.0)N for women. A significant difference was observed in lip-seal strength between men and women (p < 0.001). Oral motor functions showed a marked correlation with lip-seal strength, including tongue pressure, occlusal force, and masticatory performance and ODK (/pa/ and /ta/), tongue pressure, and masticatory ability in men and women, respectively. In women, lip-seal strength declined with increase in age.
CONCLUSIONS
Lip-seal strength was non-normally distributed in both men and women, and lip-seal strength was affected by age only in women. Lip-seal strength and multiple oral motor functions were significantly correlated. Because the indicators of perioral muscle strength and performance were correlated with lip-seal strength, lip-seal strength may also partially reflect the condition of the perioral muscles.
Topics: Adult; Bite Force; Female; Humans; Lip; Male; Mastication; Middle Aged; Pressure; Tongue; Young Adult
PubMed: 33963687
DOI: 10.1002/cre2.440 -
Odontology Apr 2023This study aimed to clarify the relationship between age and occlusal force in adults with natural dentition. A total of 385 adults (180 males and 205 females) with...
This study aimed to clarify the relationship between age and occlusal force in adults with natural dentition. A total of 385 adults (180 males and 205 females) with natural dentition participated in this study. Subjects were asked to perform maximum clenching for approximately 3 s, and the occlusal forces on both sides and habitual chewing side were calculated using a dental prescale. Regression analysis was performed by sex with occlusal forces on both sides and habitual chewing side as the dependent variable and age as the independent variable. In addition, all subjects were divided into three groups: young group (20-39 years), middle group (40-59 years), and old group (60 years and over), and the occlusal forces on both sides and habitual chewing side were compared among the three groups. The occlusal forces did not differ from 20 to 60 years old for both males and females, and the occlusal forces gradually decreased after 60 years old. The curve of the polynomial equation was the most suitable. The occlusal forces on both sides and the habitual chewing side were similar in the young and middle groups, and the values of the old group were significantly smaller than those of the other two groups. From these results, it was suggested that the occlusal force of adults with natural dentition does not differ from 20 to 60 years old and can be represented by a curve of a cubic polynomial, and it significantly decreases after 60 years old.
Topics: Male; Female; Humans; Adult; Young Adult; Middle Aged; Bite Force; Dentition; Mastication
PubMed: 36169783
DOI: 10.1007/s10266-022-00750-4 -
Anticancer Research Aug 2020We investigated whether mastication affects microglia, whose activity is thought to be associated with cognition and brain tumor progression.
BACKGROUND/AIM
We investigated whether mastication affects microglia, whose activity is thought to be associated with cognition and brain tumor progression.
MATERIALS AND METHODS
We kept mice by feeding either a hard or soft diet for 2, 4 or 8 months. After each period, we removed the whole brains and isolated microglia. The total RNA extracted from each brain's microglia was subjected to DNA microarray analysis.
RESULTS
Many genes were found to be significantly differentially expressed between hard- and soft-diet-fed mice in each group of the same feeding period. The expression of several genes involved in the regulation of actin cytoskeleton was down-regulated in the soft-diet-fed mice.
CONCLUSION
Mastication may affect microglia's roles in cognition as well as their neuroimmune activity through their activity of patrolling the brain.
Topics: Animals; Brain; Male; Mastication; Mice; Mice, Inbred C3H; Microglia; Transcriptome
PubMed: 32727798
DOI: 10.21873/anticanres.14473 -
Gerodontology Mar 2022To investigate whether masticatory movements in older patients with eating difficulties were associated with oral motor function, physical function, and appropriate food...
OBJECTIVES
To investigate whether masticatory movements in older patients with eating difficulties were associated with oral motor function, physical function, and appropriate food textures.
BACKGROUND
There are few reports on the association between masticatory movements and food textures in older patients with eating difficulties.
MATERIALS AND METHODS
This cross-sectional study involved outpatients at a clinic that specialised in eating and swallowing rehabilitation. Masticatory movements were evaluated as normal or abnormal masticatory path patterns. Oral and physical functions were assessed in terms of oral and physical status, muscle strength and motor skills. The appropriate food texture was determined based on fibreoptic endoscopic evaluation of swallowing and a video fluoroscopic swallowing study. The associations between food texture and masticatory organ, muscle strength and motor skills were analysed.
RESULTS
A total of 126 outpatients (75 men and 51 women; mean age, 78.2 years; SD, 9.6 years) were included in the analysis. 68 participants (54.0%) showed abnormal masticatory movements. Masticatory movement was associated with masticatory performance (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.98-0.99), oral diadochokinesis (OR = 0.55, CI = 0.35-0.86) and stepping test (OR = 0.92, CI = 0.86-0.97). Masticatory movement (OR = 2.94, CI = 1.23-7.01) and the number of natural teeth (OR = 0.94, CI = 0.89-0.99) were associated with normal food.
CONCLUSION
Masticatory movements in older patients with eating difficulties may be associated with appropriate food textures whilst being influenced by individual differences in systemic motor control. Masticatory movements may be as important as teeth to enjoy eating.
Topics: Aged; Cross-Sectional Studies; Deglutition; Female; Food; Humans; Male; Mastication; Tooth
PubMed: 34676589
DOI: 10.1111/ger.12596 -
Journal of the Mechanical Behavior of... Mar 2021The bite force of the piranha (Serrasalmidae) has drawn considerable attention due to its ability to effectively capture and masticate prey. Herein, we analyze...
The bite force of the piranha (Serrasalmidae) has drawn considerable attention due to its ability to effectively capture and masticate prey. Herein, we analyze theoretical anterior bite forces using a lever approach and compare them to in-vivo maximum bite forces. We provide a mechanics analysis that explains the scaling allometry of the bite force (F) with the length of the fish (l), Fαl.
Topics: Animals; Biomechanical Phenomena; Bite Force; Characiformes; Feeding Behavior; Mastication
PubMed: 33465750
DOI: 10.1016/j.jmbbm.2020.104296 -
Gerodontology Jun 2021Ageing leads to physiological cognitive decline that it is worsened in people with neurodegenerative diseases such as Alzheimer's disease. Despite the ongoing search for... (Review)
Review
INTRODUCTION
Ageing leads to physiological cognitive decline that it is worsened in people with neurodegenerative diseases such as Alzheimer's disease. Despite the ongoing search for a solution to this cognitive decline, no effective remedies have been established. It has been determined that modifiable external factors, such as oral health and occlusal function, prevent cognitive decline.
OBJECTIVE
To analyse the primary interactions between occlusal function and cognitive functions.
MAIN FINDINGS
Masticatory function is related to cognitive functions. In particular, current evidence, from both animal and human studies, suggests that the activation of masticatory muscles and proper mastication, with natural teeth or dental prosthesis, induces the release of several mediators and the activation of specific brain areas. Together, they result in higher neuronal activity, neurotrophic support, blood flow and the prevention of amyloid-beta plaque formation. Thus, all the components of the masticatory system must work together in order to preserve cognitive function.
CONCLUSIONS
Available evidence suggests that oral and cognitive health are more interconnected than previously thought. Therefore, maintenance and adequate restoration of the whole masticatory system are important for the prevention of cognitive decline. In summary, oral and chewing health lead to healthy cognitive ageing.
Topics: Aging; Animals; Cognition; Humans; Mastication; Mouth, Edentulous; Oral Health
PubMed: 33179281
DOI: 10.1111/ger.12510