BACKGROUND: The use of clear aligners is becoming more common for aesthetic orthodontic treatment, but there are still concerns about how they affect mastication biomechanics in the short and long term. The clear aligners treatment (CAT) mechanism changes the position of the mandible and maxilla, especially impacting the masseter muscle. Surface electromyography (sEMG) proves to be a useful method to evaluate masticatory muscle activity (MMA).
OBJECTIVE: To analyze the effect of clear aligners treatment on alterations in masticatory muscles (masseter, temporalis) using surface electromyography.
METHODS: Five databases (PubMed, Web of Science, SCOPUS, Cochrane Library, and Google Scholar) were searched up to March 2024.
METHODS: Studies in which MMA was evaluated after the installation of orthodontic clear aligners.
METHODS: Screening, data extraction, and quality assessments were performed by four investigators independently. The data, which evaluated temporalis and masseter muscle characteristics during CAT using surface electromyography, was extracted, and the quality of the studies was evaluated. The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS).
RESULTS: Six studies (two prospective cohort studies, three observational longitudinal studies, and one observational longitudinal case-control study) with low and moderate risk of bias were included in the qualitative synthesis. Six of these were also included in the meta-analysis. Our study investigated the dynamics of masseter and temporalis muscle activity during CAT. The results show that during maximal voluntary clenching, the masseter muscle demonstrated a significant initial increase (P < .05) followed by a subsequent non-significant decrease. It also showed that submaximal voluntary clenching consistently exhibited a significant reduction in muscle activity throughout the study period (P < .01). Assessment of muscle activity at the mandibular resting position revealed a variety of responses, with some participants showing a significant increase while others exhibited non-significant changes (P < .05, P > .05, respectively). However, the meta-analysis showed a non-significant difference in measuring masseter and temporalis muscles activity during CAT.
CONCLUSIONS: Based on existing evidence, it is reasonable to conclude that CAT affected MMA. During maximal voluntary clenching, masseter muscle activity initially increased but later decreased, while temporalis muscle activity showed mixed results. Submaximal voluntary clenching revealed a consistent decrease in muscle activity over time. Mandibular resting position assessments showed both increases and no significant changes in muscle activity. However, the existing literature is insufficient to draw concrete conclusions; therefore, well-conducted further research is needed to confirm this statement.
BACKGROUND: This systematic review and meta-analysis were registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42024522231).

BACKGROUND: Oral health and food oral-processing issues emerge with functional decline in the older adult population, potentially increasing the risk of malnutrition. Impairment of oral health is associated with poorer nutrition status; however, the relationship between oral factors and the intake of each nutrient remains poorly understood.
OBJECTIVE: The associations between different oral factors and nutrient intakes among community-dwelling older adults were investigated.
METHODS: A literature search from 5 databases (Web of Science, Scopus, Cochrane Library, Ovid [MEDLINE and Embase], and CINAHL) was completed on February 1, 2022. The search was limited to peer-reviewed articles published between the years 2012 and 2022.
METHODS: Six cross-sectional studies were included in the meta-analysis. Two authors independently completed the data extraction and summarized the study characteristics, factors adjusted for in the statistical analysis, the outcome, and summary statistics of the results.
METHODS: Meta-analyses showed evidence of a significant association between compromised oral factors (namely, denture status, chewing ability, and the number of teeth) with lower energy (weighted mean difference [WMD], -107 kcal d-1 (95% CI, -132 to -81), protein (WMD, -5.2 g d-1; 95% CI, -6.6 to -3.8), fat (WMD, -4.6 g d-1; 95% CI, -6.7 to -2.6), carbohydrate (WMD, -8.8 g d-1; 95% CI, -13.9 to -3.7), and vitamin C intakes (WMD, -12.9 mg d-1; 95% CI, -16.6 to -9.2) in older adults.
CONCLUSIONS: Oral health can be an indicator of compromised daily energy, protein, fat, carbohydrate, and vitamin C intakes in older adults. However, the small sample size of the studies included in this review and the heterogeneity among macronutrient studies should be considered. Because of the lack of studies covering all aspects of food oral processing (eg, salivary flow rate, tongue pressure), the associations between oral processing and nutrient intake were not thoroughly explored.
BACKGROUND: PROSPERO registration no. CRD42022308823.

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.

To evaluate whether complete dentures (CDs) relined with long-term resilient liners (LTRLs) favor better masticatory function, satisfaction, and quality of life among completely edentulous patients compared to conventional CDs.
This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and was registered in PROSPERO (the International Prospective Register of Systematic Reviews; CRD42021258700). The population, intervention, comparison, and outcome (PICO) purpose was to determine whether CDs relined with LTRLs favor better masticatory function, satisfaction, and quality of life among completely edentulous patients when compared to CDs. Searches were performed in the PubMed/MEDLINE, Embase, Scopus, Lilacs, BBO, and OpenGrey databases. Manual searches were also performed to identify additional primary studies.
Overall, 3,953 articles were found. After removing duplicates, reading the articles, and applying the inclusion and exclusion criteria, 15 articles were selected for qualitative analysis, totaling 422 patients with follow-up periods ranging from 1 week to 3 years. Among these, 8 studies assessed masticatory function using different methods, 2 assessed satisfaction, 1 assessed quality of life, and 4 assessed more than one outcome. Through qualitative analysis, LTRLs showed satisfactory results in most studies when compared to CDs in relation to masticatory function, satisfaction, and quality of life.
LTRLs favor better masticatory function, satisfaction, and quality of life among completely edentulous patients compared to CDs.

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.

BACKGROUND: The noteworthy correlation between bite force and masticatory performance emphasizes its significance as a meaningful and objective method for assessing oral function. Furthermore, in the study of bruxism, the measurement of intraoral bite force assumes critical importance. Given the importance of assessing occlusal forces and bite force, this systematic review aims to assess the efficacy of wireless sensors in measuring these forces.
METHODS: The search methodology employed in this systematic review adhered to the guidelines outlined by PRISMA. The strategy involved the exploration of various databases, including PubMed/MEDLINE, SCOPUS and SCIELO. An assessment tool was employed to evaluate the bias risk and study quality.
RESULTS: This systematic review encompassed six prospective clinical studies involving a total of 89 participants. Wireless sensors for measuring occlusal forces and bite forces were predominantly employed in healthy adults or individuals with bruxism, along with children undergoing orthodontic treatment. All wireless sensors employed in the studies underwent validation and reproducibility assessments, affirming their reliability. The findings indicated that all wireless sensors exhibited efficacy in detecting occlusal forces and bite forces.
CONCLUSIONS: Wireless sensors offer real-time monitoring of occlusal and bite forces, aiding in understanding force distribution and identifying bruxism patterns. Despite limited studies on their application, these sensors contribute to evolving insights. Integration into clinical practice requires careful consideration of factors like calibration and patient compliance. Ongoing research is crucial to address limitations and enhance the efficacy of wireless sensors in measuring occlusal and bite forces and managing bruxism.

BACKGROUND: Habitual betel quid chewing, a tobacco product, is a leading cause of oral cancer in Asia-Pacific countries where this practice is most prevalent. However, it is not well understood whether betel quid chewing is also a cause of adverse cardiovascular outcomes. To address this gap, we conducted a systematic literature review of peer-reviewed published studies evaluating the association between habitual betel quid use on the risk of adverse cardiovascular outcomes.
METHODS: We searched PubMed for studies assessing the correlation between betel quid chewing and cardiovascular health. We included studies if (i) they included human subjects; (ii) were peer-reviewed articles in indexed journals; and (iii) were in English. We extracted data from eligible studies and stratified them by geographical location, study designs and cardiovascular outcomes. Finally, we did a narrative synthesis of the data to identify adverse cardiovascular outcomes associated with chronic betel quid use.
RESULTS: We reviewed data from 19 studies that met the inclusion criteria. Habitual betel quid chewing was associated with hypertension, atherosclerosis, inflammation and ischaemic heart disease. In addition, betel quid use was a risk factor for arrhythmias. Interestingly, betel quid use was an independent risk factor for cardiovascular disease in women. Long-term betel quid consumption was associated with higher risks for all-cause mortality and increased overall cardiovascular risk.
CONCLUSIONS: Habitual betel quid chewing is an important cardiovascular risk factor in populations where the practice is prevalent.

Masticatory function is associated with a variety of health outcomes. The aim of this systematic review is to clarify the predictive value of masticatory function for adverse health outcomes, such as frailty, sarcopenia and malnutrition, in older adults. An online literature search covered articles published in English or Dutch in three databases (PubMed, Embase and CINAHL, last searched November 4th 2022). Inclusion criteria were: an observational study design, focus on adults aged ≥65 years and evaluation of the association between masticatory function and health outcomes. Reviews and articles published before the year 2000 were excluded. Methodological quality and risk of bias were assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the U.S. National Institutes of Health. Study population demographics, methods for assessing masticatory function, and the association between masticatory function and adverse health outcomes were extracted. From the 34 included studies, 5 studies had a prospective design, 2 had a retrospective design, and the other 27 studies had cross-sectional design. The majority of the studies were conducted in Japan (74%, n = 26). Twenty studies (59%) used one indicator for masticatory function, the other 41% used two (n = 9) or more (n = 5) indicators. Masticatory function was most frequently assessed with the maximum occlusal force (MOF) (79%, n = 27). The identified health outcomes were clustered into 6 categories: physical parameters and sarcopenia, history of falling, nutritional status, frailty, cognitive function and mortality. Despite the complex and multidimensional character of both masticatory function and most identified adverse health outcomes, some significant associations were reported. Prospective studies showed that reduced masticatory function in older adults is associated with incidence of frailty and frailty progression, cognitive decline and all-cause mortality. Regarding the other identified adverse health outcomes, i.e., physical measures and sarcopenia, history of falling and nutritional status, only cross-sectional studies were available and results were less concordant. As all prospective studies showed that reduced masticatory function in older adults is associated with adverse health outcomes, prevention of decline of masticatory function by adequate oral care may contribute to healthy ageing.

This systematic review answers the question: \"Does occlusal appliance use influence masticatory muscle function of dentate individuals with sleep bruxism?\". The literature search included six databases, grey literature, and manual search for articles. Randomized and non-randomized clinical trials were included comparing muscle function of sleep bruxers before and after receiving occlusal appliances. Risk of bias was assessed with risk of bias assessment for randomized and non-randomized clinical trials tool. Twelve studies, three represent randomized clinical trials, were included. Risk of bias was considered low, moderate, or serious. Meta-analyses indicated that soft and hard appliances did not influence muscle activity and bite force of bruxers. Qualitative analysis showed that occlusal appliance use did not influence masticatory performance and muscle volume. However, it was effective in reducing tongue force. Certainty of evidence was considered very low for muscle activity when evaluated with hard appliances, and for bite force evaluated with both appliance materials. Low certainty of evidence was observed for muscle activity with soft appliances. Based on the findings of this meta-analysis, occlusal appliances do not affect masticatory muscle function of sleep bruxers. Regardless of appliance material, the activity of masseter and temporal, and bite force of sleep bruxers was not influenced.

This study aims to compare flaps at different sites in treating soft tissue defects after oral cancer surgery and improving patients\' quality of life (QoL). Databases were searched until September 2023. The extracted data included the scores of chewing, swallowing, speech, mood, and appearance based on the University of Washington QoL questionnaire, version 4. Two types of free flaps and 2 types of pedicled tissue flaps were included. The free flaps were the forearm free flap (FFF) and anterolateral thigh flap, and the pedicled tissue flaps were the submental artery island flap and pectoralis major myocutaneous flap (PMMF). Compared with FFF, there was no significant difference in the scores of chewing, swallowing, speech, and mood among anterolateral thigh, submental artery island flap, and PMMF, and PMMF generally had a higher score than FFF only in terms of appearance, with statistical significance. There is no significant difference in chewing, swallowing, speech, and mood between flaps from different sites in repairing postoperative soft tissue defects of oral cancer. Therefore, the widely used FFF may be the preferred choice considering the QoL of patients after oral cancer surgery.