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1.
Prog Orthod ; 25(1): 17, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38735912

ABSTRACT

BACKGROUND: Low-intensity electrical stimulation (LIES) is considered a relatively recent technology that has received little attention in orthodontics as a method of acceleration. This study aimed to evaluate patient-reported outcome measures when LIES is used to accelerate the en-masse retraction of the upper anterior teeth. MATERIALS AND METHODS: The sample consisted of 40 patients (8 males, 32 females; mean age 21.1 ± 2.3 years), with Class II division I malocclusion who required extraction of the first premolars to retract upper anterior teeth. They were randomly assigned to the LIES group (n = 20) and the conventional en-masse retraction group (CER; n = 20). Patient responses regarding pain, discomfort, burning sensation, swelling, chewing difficulty, speech difficulty, and painkillers' consumption were recorded at these nine assessment times: 24 h (T1), 3 days (T2), and 7 days (T3) after force application, then in the second month after 24 h (T4), 3 days (T5), and 7 days (T6) of force re-activation, and finally after 24 h (T7), 3 days (T8), and 7 days (T9) of force re-activation in the third month. RESULTS: The mean values of pain perception were smaller in the LIES group than those in the CER group at all assessment times with no statistically significant differences between the two groups except during the second and third months (T5, T6, T8, and T9; P < 0.005). However, discomfort mean values were greater in the LIES group with significant differences compared to CER group during the first week of the follow-up only (T1, T2, and T3; P < 0.005). Burning sensation levels were very mild in the LIES group, with significant differences between the two groups at T1 and T2 only (P < 0.001). Speech difficulty was significantly greater in the LIES group compared to CER group at all studied times (P < 0.001). High levels of satisfaction and acceptance were reported in both groups, without any significant difference. CONCLUSION: Both the LIES-based acceleration of en-masse retraction of upper anterior teeth and the conventional retraction were accompanied by mild to moderate pain, discomfort, and chewing difficulty on the first day of retraction. These sensations gradually decreased and almost disappeared over a week after force application or re-activation. TRIAL REGISTRATION: ClinicalTrials.gov, ClinicalTrials.gov, NCT05920525. Registered 17 June 2023 - retrospectively registered, http://clinicaltrials.gov/study/NCT05920525?term=NCT05920525&rank=1 .


Subject(s)
Patient Reported Outcome Measures , Tooth Movement Techniques , Humans , Female , Male , Tooth Movement Techniques/instrumentation , Tooth Movement Techniques/methods , Young Adult , Malocclusion, Angle Class II/therapy , Tooth Extraction , Bicuspid , Electric Stimulation/methods , Mastication/physiology , Incisor , Maxilla , Pain Measurement
2.
Food Res Int ; 187: 114459, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38763692

ABSTRACT

Staple foods serve as vital nutrient sources for the human body, and chewiness is an essential aspect of food texture. Age, specific preferences, and diminished eating functions have broadened the chewiness requirements for staple foods. Therefore, comprehending the formation mechanism of chewiness in staple foods and exploring approaches to modulate it becomes imperative. This article reviewed the formation mechanisms and quality control methods for chewiness in several of the most common staple foods (rice, noodles, potatoes and bread). It initially summarized the chewiness formation mechanisms under three distinct thermal processing methods: water medium, oil medium, and air medium processing. Subsequently, proposed some effective approaches for regulating chewiness based on mechanistic changes. Optimizing raw material composition, controlling processing conditions, and adopting innovative processing techniques can be utilized. Nonetheless, the precise adjustment of staple foods' chewiness remains a challenge due to their diversity and technical study limitations. Hence, further in-depth exploration of chewiness across different staple foods is warranted.


Subject(s)
Bread , Food Handling , Oryza , Solanum tuberosum , Bread/analysis , Humans , Food Handling/methods , Mastication
3.
MMW Fortschr Med ; 166(9): 22-23, 2024 05.
Article in German | MEDLINE | ID: mdl-38755364
4.
Anat Histol Embryol ; 53(3): e13050, 2024 May.
Article in English | MEDLINE | ID: mdl-38706182

ABSTRACT

Dogs are animals with strong bite force. This strong bite mechanism has led to significant changes in the skeletal system such as fossa masseterica. It can be thought that one side is used more than the other side in chewing and is related to the preference of using the same side's hand, eye and foot. In the study, directional asymmetry and fluctuating asymmetry, which occurs as a result of chewing asymmetry, were examined on the first molar teeth and the fossa masseterica in 85 dog mandibles including a wide diversity of morphotypes. The association of high PC1 values for directional asymmetry with a pronounced cranial index, as evident in breeds like Pekingese, Pomeranian and Bulldog, indicates a potential evolutionary or selective breeding trend favouring brachycephaly. On the contrary, guardian breeds like the German shepherd and Bernese mountain dog, which typically require strong jaws for their roles, showcased reduced PC1 values, which might be related to their functional morphology. Similarly, the PCA results for the first molar teeth shape variations also highlighted the influence of cranial shape, with boxer dogs displaying notably higher PC1 values. The fluctuating asymmetrical distributions provided valuable insights into individualistic variations. Interestingly, no specific breed distribution trend was observed for these asymmetries, indicating a more individual-based variation rather than breed-based. It is essential to note that while these results provide valuable insights, further studies are required to understand the underlying causes better. Factors like genetic variations, developmental processes, dietary habits and external environmental factors could play pivotal roles in these observed morphological differences.


Subject(s)
Mastication , Molar , Animals , Dogs/anatomy & histology , Dogs/physiology , Molar/anatomy & histology , Molar/physiology , Mastication/physiology , Male , Female , Mandible/anatomy & histology , Bite Force
5.
J Morphol ; 285(5): e21699, 2024 May.
Article in English | MEDLINE | ID: mdl-38715161

ABSTRACT

In 1974, Sue Herring described the relationship between two important performance variables in the feeding system, bite force and gape. These variables are inversely related, such that, without specific muscular adaptations, most animals cannot produce high bite forces at large gapes for a given sized muscle. Despite the importance of these variables for feeding biomechanics and functional ecology, the paucity of in vivo bite force data in primates has led to bite forces largely being estimated through ex vivo methods. Here, we quantify and compare in vivo bite forces and gapes with output from simulated musculoskeletal models in two craniofacially distinct strepsirrhines: Eulemur, which has a shorter jaw and slower chewing cycle durations relative to jaw length and body mass compared to Varecia. Bite forces were collected across a range of linear gapes from 16 adult lemurs (suborder Strepsirrhini) at the Duke Lemur Center in Durham, North Carolina representing three species: Eulemur flavifrons (n = 6; 3F, 3M), Varecia variegata (n = 5; 3F, 2M), and Varecia rubra (n = 5; 5F). Maximum linear and angular gapes were significantly higher for Varecia compared to Eulemur (p = .01) but there were no significant differences in recorded maximum in vivo bite forces (p = .88). Simulated muscle models using architectural data for these taxa suggest this approach is an accurate method of estimating bite force-gape tradeoffs in addition to variables such as fiber length, fiber operating range, and gapes associated with maximum force. Our in vivo and modeling data suggest Varecia has reduced bite force capacities in favor of absolutely wider gapes compared to Eulemur in relation to their longer jaws. Importantly, our comparisons validate the simulated muscle approach for estimating bite force as a function of gape in extant and fossil primates.


Subject(s)
Bite Force , Animals , Biomechanical Phenomena , Jaw/anatomy & histology , Jaw/physiology , Lemur/physiology , Lemur/anatomy & histology , Mastication/physiology , Male , Female
6.
Swiss Dent J ; 134(2): 53-71, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38739770

ABSTRACT

Oral healthcare among the frail is an underestimated geriatric care element. While neglected oral health (OH) is a well-established risk factor for frailty, frailty can be a risk factor for subsequent OH problems. The cross-sectional investigation nested into the SAPALDIA sub-cohort of citizens aged 52 years and older, aims to stimulate longitudinal research into aspects that accelerate poor OH among frail individuals. The hypothesis investigated was that (pre-) frail individuals are more likely to have missing teeth replaced with removable dental prostheses (RDP) resulting in difficulties with chewing. The study included 1489 participants undergoing geriatric assessments and oral examination. The main predictor was frailty status (non-frail; pre-frail; frail), based on Fried's frailty phenotype. The main outcomes of interest were non-functional dentition (presence of ≤ 19 natural teeth), presence of any RDP and self-reported difficulties with chewing. Pre-frailty and frailty were not associated with the presence of ≤ 19 natural teeth, but were associated with a higher RDP prevalence. The presence of at least one complete denture (CD) had 1.71 fold and 2.54 folds higher odds among pre-frail and frail, respectively, compared to non-frail individuals. Frail individuals with CD reported chewing difficulties 7.8 times more often than non-frail individuals without CD. The results are in line with the hypothesis that (pre-) frail individuals may be more likely to have tooth loss restored by RDPs. Future longitudinal research needs to assess potential barriers to oral hygiene and fixed dental prostheses among (pre-) frail and to study their oral health-related quality of life.


Subject(s)
Frail Elderly , Mastication , Humans , Aged , Female , Male , Mastication/physiology , Middle Aged , Cross-Sectional Studies , Switzerland/epidemiology , Cohort Studies , Aged, 80 and over , Geriatric Assessment , Oral Health/statistics & numerical data , Frailty/epidemiology , Denture, Partial, Removable , Denture, Complete/adverse effects
7.
PLoS One ; 19(5): e0300354, 2024.
Article in English | MEDLINE | ID: mdl-38691559

ABSTRACT

Oral cancer (OC) is the most common cancer in Pakistani males and the second most common in females. Major risk factors include peculiar chewing habits, human papillomavirus (HPV) infection and molecular pathways. However, less data is available for this avertible cancer regarding its association with high-risk HPV (HR-HPV) and chewing habits in this region. Therefore, this study was done to determine the prevalence of HR-HPV in oral squamous cell carcinoma (OSCC) and its correlation with p16 and chewing habits. Formalin-fixed paraffin-embedded (FFPE) biopsy specimens of 186 samples were tested for HR-HPV type 16/18 by PCR, followed by p16 immunostaining (IHC) in a subset of cases (n = 50). Appropriate statistical tests were applied to find the association between HR-HPV/p16 and peculiar chewing habits with significance criteria of p<0.05 with 95% CI. HR-HPV (type 16 &18) was present in seven out of 186 cases (3.8%). Of these seven cases, five were positive for HPV16, whereas two were positive for HPV16/18. The overall expression of p16 protein in 50 samples was 38% (n = 19), and among these 19-IHC positive samples, 26% were positive for HR-HPV DNA. No significant association was found between HR-HPV positivity and p16 and chewing habits (p>0.05). It was concluded that HR-HPV prevalence in OSCC was very low in our population, with no statistically significant correlation with p16 and chewing habits. These results suggest the role of HR-HPV as an independent risk factor in OSCC in the local setting.


Subject(s)
Carcinoma, Squamous Cell , Human papillomavirus 16 , Mouth Neoplasms , Papillomavirus Infections , Humans , Mouth Neoplasms/virology , Mouth Neoplasms/epidemiology , Male , Female , Carcinoma, Squamous Cell/virology , Carcinoma, Squamous Cell/epidemiology , Middle Aged , Prevalence , Papillomavirus Infections/epidemiology , Papillomavirus Infections/virology , Adult , Human papillomavirus 16/genetics , Human papillomavirus 16/isolation & purification , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Risk Factors , Aged , Human papillomavirus 18/isolation & purification , Human papillomavirus 18/genetics , Mastication , Pakistan/epidemiology , Human Papillomavirus Viruses
8.
Clin Oral Investig ; 28(6): 330, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38772987

ABSTRACT

OBJECTIVES: The aim of this multi-center pilot study was to assess the viability and feasibility of a novel treatment concept - the canine-positioned single implant mandibular overdenture (c-SIMO), with the single implant placed on the patient's preferred chewing side instead of the midline. MATERIALS AND METHODS: Participants received a single implant in the canine region of their preferred chewing side, based on an Asymmetry Index observed during mastication. The pre-existing mandibular denture was transformed into a c-SIMO on a spherical attachment. The primary outcome was oral health-related quality of life (OHRQoL), measured with GOHAI and OHIP-EDENT. Secondary outcomes included denture satisfaction index (DSI), chewing efficiency (CE), maximum bite force (MBF), implant survival and success, and prosthetic maintenance. Data analysis included descriptive statistics and bivariate comparison tests. RESULTS: Fifteen participants received the c-SIMO treatment (mean age: 69.9 ± 7.0). Implant success and survival rates were 100% at 1 year. Patient-reported outcome measures improved significantly compared to pre-treatment values (OHIP-EDENT: p = 0.001; DSI: p = 0.001; GOHAI: p = 0.002). Masticatory outcomes also improved significantly (CE: p = 0.001; overall MBF: p = 0.005). Post-implant, MBF was significantly higher in the ipsilateral side compared to the contralateral side at 2 weeks (p = 0.019) and 3 months (p = 0.015), but no longer at T3 (p = 0.730). Common prosthodontic events included denture base adjustments (n = 17) and matrix activation (n = 9). CONCLUSIONS: This pilot study concludes that c-SIMO is a promising treatment option, and a potential alternative to the single midline implant overdenture. CLINICAL RELEVANCE: The novel treatment concept of a canine-positioned single implant mandibular overdenture could be a viable treatment alternative to the midline positioning.


Subject(s)
Dental Prosthesis, Implant-Supported , Denture, Overlay , Feasibility Studies , Mastication , Quality of Life , Humans , Pilot Projects , Aged , Male , Female , Mastication/physiology , Cuspid , Dental Implants, Single-Tooth , Patient Satisfaction , Middle Aged , Mandible , Denture Design
9.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 49(1): 47-53, 2024 Jan 28.
Article in English, Chinese | MEDLINE | ID: mdl-38615165

ABSTRACT

Trigeminal neuralgia is a manifestation of orofacial neuropathic pain disorder, always deemed to be an insurmountable peak in the field of pain research and treatment. The pain is recurrent, abrupt in onset and termination similar to an electric shock or described as shooting. A poor quality of life has been attributed to trigeminal neuralgia, as the paroxysms of pain may be triggered by innocuous stimuli on the face or inside the oral cavity, such as talking, washing face, chewing and brushing teeth in daily life. The pathogenesis of trigeminal neuralgia has not been fully elucidated, although the microvascular compression in the trigeminal root entry zone is generally considered to be involved in the emergence and progression of the pain disorder. In addition, orofacial neuropathic pain restricted to one or more divisions of the trigeminal nerve might be secondary to peripheral nerve injury. Based on current hypotheses regarding the potential causes, a variety of animal models have been designed to simulate the pathogenesis of trigeminal neuralgia, including models of compression applied to the trigeminal nerve root or trigeminal ganglion, chronic peripheral nerve injury, peripheral inflammatory pain and center-induced pain. However, it has not yet been possible to determine which model can be perfectly employed to explain the mechanisms. The selection of appropriate animal models is of great significance for the study of trigeminal neuralgia. Therefore, it is necessary to discuss the characteristics of the animal models in terms of animal strains, materials, operation methods and behavior observation, in order to gain insight into the research progress in animal models of trigeminal neuralgia. In the future, animal models that closely resemble the features of human trigeminal neuralgia pathogenesis need to be developed, with the aim of making valuable contributions to the relevant basic and translational medical research.


Subject(s)
Neuralgia , Peripheral Nerve Injuries , Trigeminal Neuralgia , Animals , Humans , Quality of Life , Mastication , Models, Animal
10.
J Morphol ; 285(5): e21696, 2024 May.
Article in English | MEDLINE | ID: mdl-38639429

ABSTRACT

In infants and children with feeding and swallowing issues, modifying solid foods to form a liquid or puree is used to ensure adequate growth and nutrition. However, the behavioral and neurophysiological effects of prolonged use of this intervention during critical periods of postnatal oral skill development have not been systematically examined, although substantial anecdotal evidence suggests that it negatively impacts downstream feeding motor and coordination skills, possibly due to immature sensorimotor development. Using an established animal model for infant and juvenile feeding physiology, we leverage X-ray reconstruction of moving morphology to compare feeding behavior and kinematics between 12-week-old pigs reared on solid chow (control) and an age- and sex-matched cohort raised on the same chow softened to a liquid. When feeding on two novel foods, almond and apple, maintenance on a soft diet decreases gape cycle duration, resulting in a higher chewing frequency. When feeding on almonds, pigs in this group spent less time ingesting foods compared to controls, and chewing cycles were characterized by less jaw rotation about a dorsoventral axis (yaw) necessary for food reduction. There was also a reduced tendency to alternate chewing side with every chew during almond chewing, a behavioral pattern typical of pigs. These more pronounced impacts on behavior and kinematics during feeding on almonds, a tougher and stiffer food than apples, suggest that food properties mediate the behavioral and physiological impacts of early texture modification and that the ability to adapt to different food properties may be underdeveloped. In contrast, the limited effects of food texture modification on apple chewing indicate that such intervention/treatment does not alter feeding behavior of less challenging foods. Observed differences cannot be attributed to morphology because texture modification over the treatment period had limited impact on craniodental growth. Short-term impacts of soft-texture modification during postweaning development on feeding dynamics should be considered as potential negative outcomes of this treatment strategy.


Subject(s)
Feeding Behavior , Mastication , Swine , Animals , Mastication/physiology , Biomechanical Phenomena , Feeding Behavior/physiology , Diet , Growth and Development
11.
Nature ; 628(8008): 569-575, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38570681

ABSTRACT

Shuotheriids are Jurassic mammaliaforms that possess pseudotribosphenic teeth in which a pseudotalonid is anterior to the trigonid in the lower molar, contrasting with the tribosphenic pattern of therian mammals (placentals, marsupials and kin) in which the talonid is posterior to the trigonid1-4. The origin of the pseudotribosphenic teeth remains unclear, obscuring our perception of shuotheriid affinities and the early evolution of mammaliaforms1,5-9. Here we report a new Jurassic shuotheriid represented by two skeletal specimens. Their complete pseudotribosphenic dentitions allow reidentification of dental structures using serial homology and the tooth occlusal relationship. Contrary to the conventional view1,2,6,10,11, our findings show that dental structures of shuotheriids can be homologized to those of docodontans and partly support homologous statements for some dental structures between docodontans and other mammaliaforms6,12. The phylogenetic analysis based on new evidence removes shuotheriids from the tribosphenic ausktribosphenids (including monotremes) and clusters them with docodontans to form a new clade, Docodontiformes, that is characterized by pseudotribosphenic features. In the phylogeny, docodontiforms and 'holotherians' (Kuehneotherium, monotremes and therians)13 evolve independently from a Morganucodon-like ancestor with triconodont molars by labio-lingual widening their posterior teeth for more efficient food processing. The pseudotribosphenic pattern passed a cusp semitriangulation stage9, whereas the tribosphenic pattern and its precursor went through a stage of cusp triangulation. The two different processes resulted in complex tooth structures and occlusal patterns that elucidate the earliest diversification of mammaliaforms.


Subject(s)
Biological Evolution , Fossils , Mammals , Tooth , Animals , Eutheria/anatomy & histology , Mammals/anatomy & histology , Mammals/classification , Mammals/physiology , Marsupialia/anatomy & histology , Molar/anatomy & histology , Molar/physiology , Phylogeny , Tooth/anatomy & histology , Tooth/physiology , Mastication
12.
J Anim Sci ; 1022024 Jan 03.
Article in English | MEDLINE | ID: mdl-38581217

ABSTRACT

Pelleted total mixed ration (P-TMR) feeding, which has become a common practice in providing nutrition for fattening sheep, requires careful consideration of the balance between forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) to maintain proper rumen functions. The present study aimed to investigate the effects of the dietary FNDF/RDS ratio (FRR) on chewing activity, ruminal fermentation, ruminal microbes, and nutrient digestibility in Hu sheep fed a P-TMR diet. This study utilized eight ruminally cannulated male Hu sheep, following a 4 × 4 Latin square design with 31 d each period. Diets consisted of four FRR levels: 1.0 (high FNDF/RDS ratio, HFRR), 0.8 (middle high FNDF/RDS ratio, MHFRR), 0.6 (middle low FNDF/RDS ratio, MLFRR), and 0.4 (low FNDF/RDS ratio, LFRR). Reducing the dietary FRR levels resulted in a linear decrease in ruminal minimum pH and mean pH, while linearly increasing the duration and area of pH below 5.8 and 5.6, as well as the acidosis index. Sheep in the HFRR and MHFRR groups did not experience subacute ruminal acidosis (SARA), whereas sheep in another two groups did. The concentration of total volatile fatty acid and the molar ratios of propionate and valerate, as well as the concentrate of lactate in the rumen linearly increased with reducing dietary FRR, while the molar ratio of acetate and acetate to propionate ratio linearly decreased. The degradability of NDF and ADF for alfalfa hay has a quadratic response with reducing the dietary FRR. The apparent digestibility of dry matter, organic matter, neutral detergent fiber, and acid detergent fiber linearly decreased when the dietary FRR was reduced. In addition, reducing the dietary FRR caused a linear decrease in OTUs, Chao1, and Ace index of ruminal microflora. Reducing FRR in the diet increased the percentage of reads assigned as Firmicutes, but it decreased the percentage of reads assigned as Bacteroidetes in the rumen. At genus level, the percentage of reads assigned as Prevotella, Ruminococcus, Succinivibrio, and Butyrivibrio linearly decreased when the dietary FRR was reduced. The results of this study demonstrate that the dietary FRR of 0.8 is crucial in preventing the onset of SARA and promotes an enhanced richness of ruminal microbes and also improves fiber digestibility, which is a recommended dietary FRR reference when formulating P-TMR diets for sheep.


Forage neutral detergent fiber (FNDF) and rumen degradable starch (RDS) are key components of carbohydrates in the diet for ruminants, which would reflect saliva secretion and the acid production potential of feed. However, appropriate FNDF to RDS ratios (FRR) applicable to ruminants under the condition of pelleted total mixed ration (P-TMR) feeding have not been reported. In this study, we investigated the effects of the dietary FRR on chewing activity, ruminal fermentation, ruminal microbial communities, and nutrient digestibility of Hu sheep under P-TMR feeding. The results indicate that reducing dietary FRR levels would induce acidosis in sheep, which negatively affected fiber utilization and ruminal bacterial communities. The FRR of 0.8 was a recommended dietary FRR when formulating a P-TMR diet for fattening sheep, as indicated by decreased ruminal acidosis risk and increased richness of ruminal microbes in the rumen as well as nutrient digestibility.


Subject(s)
Acidosis , Sheep Diseases , Male , Female , Animals , Sheep , Milk/metabolism , Mastication/physiology , Starch/metabolism , Lactation/physiology , Detergents/metabolism , Silage/analysis , Propionates/metabolism , Fermentation , Rumen/metabolism , Dietary Fiber/metabolism , Dietary Carbohydrates/metabolism , Diet/veterinary , Nutrients , Acetates/metabolism , Acidosis/veterinary , Digestion/physiology
13.
Comput Methods Programs Biomed ; 250: 108174, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38640839

ABSTRACT

STATEMENT OF PROBLEM: Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs. PURPOSE: To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function. MATERIAL AND METHODS: We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation. RESULTS: We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%. CONCLUSION: These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.


Subject(s)
Computer Simulation , Mandible , Mandibular Reconstruction , Mastication , Humans , Mandibular Reconstruction/methods , Mandible/surgery , Biomechanical Phenomena , Bite Force
14.
Exp Appl Acarol ; 92(4): 567-686, 2024 May.
Article in English | MEDLINE | ID: mdl-38639851

ABSTRACT

The dentition of the chelal moveable digit in cohabiting astigmatids from UK beehives (i.e., Carpoglyphus lactis (Linnaeus), Glycyphagus domesticus (DeGeer), and Tyrophagus putrescentiae (Schrank)) is characterised for the first time using quantitative tribological measures within a 2D mechanical model. The trophic function of astigmatid chelae are reviewed in terms of macroscopic tools used by humans including hooking devices, pliers, shears, rasps and saws. Comparisons to oribatid claws and isopod dactyli are made. The overall pattern of the moveable digit form of T. putrescentiae is not just a uniformly shrunken/swollen version between the other two taxa at either the macro- or micro-scale. Mastication surface macro-roughness values are in the range of international Roughness Grade Numbers N5-N6. The moveable digit of C. lactis has low rugosity values compared to the glycyphagid and acarid (which are topographically more similar and match that roughness typical of some coral reef surfaces). C. lactis has the most plesiomorphic moveable digit form. The mastication surface of all three species as a chewing tool is distinctly ornamented despite the moveable digit of C. lactis looking like a bar-like beam. The latter has more opportunities to be a multifunctional tool behaviourally than the other two species. Little evidence of any differences in the 'spikiness' of any 'toothiness' is found. Some differences with laboratory cultured specimens are found in C. lactis and possibly T. putrescentiae suggesting where selection on the digit may be able to occur. The chelal surface of T. putrescentiae has been deformed morphologically during evolution the most, that of C. lactis the least. Repeated localised surface differentiation is a feature of the moveable digit in G. domesticus compared to the likely more concerted changes over certain nearby locations in T. putrescentiae. An impactful chelal teeth design is present in G. domesticus but this is more equivocal in T. putrescentiae. Pockets within the mastication surface of the glycyphagid (and to some extent for the acarid) may produce foodstuff crunch forces of the scale of the chelal tips of oribatids. The moveable digit dentition of G. domesticus is adapted to shred foodstuff (like a ripsaw) more than that of the grazing/shearing dentition of T. putrescentiae. The collecting 'picker' design of C. lactis posterior teeth matches the size of Bettsia alvei hyphae which attacks hive-stored pollen. Detritus accumulated in chelal digit gullets through a sawing action matches the smallest observed ingested material. The dentition of C. lactis should produce less friction when moving through food material than G. domesticus. C. lactis is the most hypocarnivorous and may 'skim' through fluids when feeding. Astigmatid teeth do matter. The three commensal species can avoid direct competition. Future work is proposed in detail.


Subject(s)
Mites , Animals , Mites/physiology , Mites/anatomy & histology , Tooth/anatomy & histology , Mastication/physiology , United Kingdom
15.
Behav Processes ; 218: 105042, 2024 May.
Article in English | MEDLINE | ID: mdl-38679342

ABSTRACT

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.


Subject(s)
Behavior, Animal , Mastication , Social Behavior , Animals , Female , Mastication/physiology , Swine/physiology , Behavior, Animal/physiology
16.
Exp Appl Acarol ; 92(4): 687-737, 2024 May.
Article in English | MEDLINE | ID: mdl-38622432

ABSTRACT

Changes in the functional shape of astigmatan mite moveable digit profiles are examined to test if Tyrophagus putrescentiae (Acaridae) is a trophic intermediate between a typical micro-saprophagous carpoglyphid (Carpoglyphus lactis) and a common macro-saprophagous glycyphagid (Glycyphagus domesticus). Digit tip elongation in these mites is decoupled from the basic physics of optimising moveable digit inertia. Investment in the basal ramus/coronoid process compared to that for the moveable digit mastication length varies with feeding style. A differentiated ascending ramus is indicated in C. lactis and in T. putrescentiae for different trophic reasons. Culturing affects relative investments in C. lactis. A markedly different style of feeding is inferred for the carpoglyphid. The micro-saprophagous acarid does not have an intermediate pattern of trophic functional form between the other two species. Mastication surface shape complexity confirms the acarid to be heterodontous. T. putrescentiae is a particularly variably formed species trophically. A plausible evolutionary path for the gradation of forms is illustrated. Digit form and strengthening to resist bending under occlusive loads is explored in detail. Extensions to the analytical approach are suggested to confirm the decoupling of moveable digit pattern from cheliceral and chelal adaptations. Caution is expressed when interpreting ordinations of multidimensional data in mites.


Subject(s)
Acaridae , Animals , Acaridae/physiology , Acaridae/growth & development , Acaridae/anatomy & histology , Extremities/anatomy & histology , Biomechanical Phenomena , Feeding Behavior , Mastication , Female
17.
Nutrients ; 16(8)2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38674787

ABSTRACT

Given the changes in the digestive tract post-bariatric surgery, adapting to a new pattern of eating behavior becomes crucial, with special attention to the specifics of chewing mechanics. This study aimed to investigate the association between self-perception of chewing, chewing behavior, and the presence of gastrointestinal symptoms in preoperative patients undergoing bariatric surgery. Sixty adult candidates for bariatric surgery at a public hospital in Belém (Brazil) were analyzed. Participants predominantly exhibited unilateral chewing patterns (91.6%), a fast chewing rhythm (73.3%), a large food bolus (80%), liquid intake during meals (36.7%), and 41.7% reported that chewing could cause some issue. Significant associations were found between the perception of causing problems and chewing scarcity (p = 0.006), diarrhea (p = 0.004), absence of slow chewing (p = 0.048), and frequent cutting of food with front teeth (p = 0.034). These findings reveal a relationship between the perception of chewing problems and chewing scarcity, presence of diarrhea, and fast chewing.


Subject(s)
Bariatric Surgery , Mastication , Self Concept , Humans , Female , Male , Adult , Middle Aged , Feeding Behavior/psychology , Gastrointestinal Diseases/psychology , Gastrointestinal Diseases/etiology , Diarrhea/etiology , Brazil , Cross-Sectional Studies , Obesity, Morbid/surgery , Obesity, Morbid/psychology
19.
BMC Oral Health ; 24(1): 462, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38627762

ABSTRACT

BACKGROUND: This cross-sectional study aimed to identify factors associated with age-related changes in masticatory performance (MP) and oral diadochokinesis (ODK) and to provide normal values in healthy old adults for the diagnosis of oral frailty. METHODS: A total of 385 participants were divided into three age groups (Gr1-3): 20-64 years, 65-74 years, and ≥ 75 years. To investigate tongue-lip motor function, ODK was assessed as the number of repetitions of the monosyllables /pa/ta/ka/. Four questionnaires were used to assess subjective masticatory ability, cognitive ability, and psychological status. MP, bite force, and occlusal area were tested to assess dynamic objective masticatory function, and the number of remaining teeth and functional tooth pairs were determined to assess static objective masticatory function. Handgrip strength (HG), oral dryness, and tongue pressure (TP) were assessed to identify influencing factors. Intergroup differences were evaluated by ANOVA and the Kruskal‒Wallis test, and correlations between ODK and orofacial factors were evaluated. RESULTS: This study revealed significant age-related declines in TP, HG, and ODK, especially after 65 years of age. Factors affecting MP were posterior teeth, the Eichner index, bite force, occluding area, the Korean Mini-Mental State Examination (KMMSE) score, and ODK. Each ODK syllable was associated with different factors, but common factors associated with ODK were MP, HG, and PHQ-9 score. For the syllables /pa/ta/, the Eichner Index, TP, and oral dryness were also associated. For the syllable /ka/ in Gr3, MP, TP, HG, oral dryness, and the KMMSE score were associated. CONCLUSIONS: These results could provide practical guidelines for oral rehabilitation in old adults and contribute to improving the understanding of age-related changes in oral function and the multidimensional nature of masticatory dynamics.


Subject(s)
Tongue , Xerostomia , Adult , Humans , Aged , Hand Strength , Cross-Sectional Studies , Pressure , Mastication
20.
Nutrition ; 123: 112418, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38569254

ABSTRACT

OBJECTIVE: Orthognathic surgery is a complex orofacial surgery that can significantly impact occlusal function and effect nutritional and quality of life parameters. This study aimed to evaluate alterations in dietary intake, chewing function, physical activity, and oral health-related quality of life of patients undergoing orthognathic surgery. RESEARCH METHODS AND PROCEDURES: In this prospective longitudinal study, the assessments were conducted at: preoperatively (T0) and postoperative first week (T1), second week (T2), first month (T3), and third month (T4) between May 2021 and March 2023. Sociodemographic questionnaire, 24-h dietary recall record, chewing ability form, International Physical Activity Questionnaire, and Oral Health Impact Profile-14 (OHIP-14) was applied at face-to-face interviews. RESULTS: Seventy eligible orthognathic surgery patients were evaluated, and 37 patients (52.8%) completed this study. Energy and fat intake significantly decreased from T0 to T1 (P < 0.001) and returned to basis by T4 (P = 0.015). Fiber intake was found to be lowest at T1 and T2 compared with other time points (P < 0.001). Chewing ability showed a deterioration and then improvement; however, patients still had difficulties chewing hard foods at T4. The OHIP-14 increased at T2 and T3 from T0 (P < 0.001 and P = 0.021, respectively) and showed a significant improvement at T4 (P < 0.05). CONCLUSION: The findings indicate a temporary decline in nutritional intake and chewing ability with subsequent recovery by the third month postsurgery. These changes, along with the trends in oral health-related quality of life, underscore the need for tailored nutritional and functional rehabilitation programs following orthognathic surgery.


Subject(s)
Mastication , Nutritional Status , Oral Health , Orthognathic Surgical Procedures , Quality of Life , Humans , Female , Male , Oral Health/statistics & numerical data , Prospective Studies , Longitudinal Studies , Mastication/physiology , Adult , Young Adult , Postoperative Period , Surveys and Questionnaires , Preoperative Period , Diet/statistics & numerical data , Diet/methods , Exercise , Adolescent
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