BACKGROUND: Children with Down syndrome (DS) experience more difficulties with oral motor skills, including chewing, drinking, and swallowing. The present study attempts to measure the preliminary effectiveness of Global Intensive Feeding Therapy (GIFT) in DS. GIFT is a new rehabilitation program addressing the specific difficulties and needs of each child, focusing on sensory and motor oral abilities. It follows an intensive schedule comprising 15 sessions over 5 consecutive days, with 3 sessions per day. The principles of GIFT are applied with specific objectives for DS.
METHODS: GIFT was preliminarily implemented among 20 children diagnosed with DS. To measure the efficacy of GIFT, the Karaduman Chewing Performance Scale (KCPS), the International Dysphagia Diet Standardization Initiative (IDDSI), and the Pediatric Screening-Priority Evaluation Dysphagia (PS-PED) were used. Data were analyzed using the Wilcoxon signed-rank test before (T0) and after intervention (T1) and at one-month follow-up (T2). The effect size was also measured for specific outcomes, using Kendall\'s W.
RESULTS: Our findings revealed that children with DS showed no risk of dysphagia according to the PS-PED (mean score 2.80). Furthermore, statistically significant improvements in chewing performance were observed, as measured by the KCPS (p < 0.01), as well as in texture acceptance and modification, as measured by the IDDSI post-intervention (p < 0.01). For both the KCPS and IDDSI, a large effect size was found (Kendall\'s W value > 0.8). Parents/caregivers continued using GIFT at home, and this allowed for a positive outcome at the one-month follow-up.
CONCLUSIONS: GIFT proved to be effective in the rehabilitation of feeding and swallowing disorders in children with DS, as well as for food acceptance.

This study examined the effects of khat chewing on oral gingival conditions by adopting a targeted process which combined physicochemical analyses of the teeth, histopathological examinations of the gums, and bioinformatics modeling. The physicochemical evaluation of teeth in khat consumers compared to non-consumers was carried out using specific analytical techniques; hence, the results of this initial investigation revealed significant erosion of the tooth enamel due to khat chewing, as well as an alteration of the essential chemical composition of the teeth. Additionally, the histopathological analyses complemented preliminary studies by showing severe inflammation of the gums and oral mucosa in khat users. The understanding of these studies was enriched by bioinformatics analysis, where modeling was carried out via computational methods. This analytical phase examined molecular docking mechanisms, including the interaction between cathinone, the main alkaloid of khat, and the protein receptors involved in the protection of gingival tissues against infections. In summary, this multidisciplinary research provided an in-depth view of the oral health issues related to khat chewing, combining experimental studies with bioinformatics perspectives.

Nowadays, aligners represent a possible therapeutical approach that combines both esthetic and function in order to address dental malocclusion. However, they require a significant level of compliance from the patient. According to the manufacturer, at least 22 h of wearing a day is demanded to reach the optimal therapeutical level; hence, aligners can only be removed during meals. Patients\' compliance might increase and the duration of the treatment might decrease if they were allowed to eat with aligners on. The idea of patients keeping the aligners on during meals has been contemplated, not only to favor patients\' compliance but also treatment effectiveness. This study aims to assess the degree of chewing difficulty that aligners cause when eating certain kinds of food and the quantity of residue left.
METHODS: A questionnaire titled \"Questionnaire for the Assessment of Masticatory Function with Aligners\" was administered using Google Forms to 240 patients in treatment with clear aligners. The survey was validated through the reliability test using the test-retest method. This method had a higher correlation coefficient of 0.9 across all items (with a cutoff of 0.8) with statistical significance, and an excellent internal correlation coefficient (α > 0.9). The statistical analysis performed consisted of descriptive analysis, frequencies, percentages, Pearson\'s correlation test and Friedman\'s test.
RESULTS: Pearson\'s test showed a statistically significant correlation between all items except between meat or clams and yogurt or ice cream and with mozzarella or soft cheese regarding food chewing difficulties. Pearson\'s test showed a statistically significant correlation between all items regarding food residues. A total of 69.2% of the cohort reported some movements of aligners during mastication. In total, 88.3% of them affirmed not to have perceived deformations or breakage of aligners during chewing. Furthermore, 79.2% of them declared that they would continue to eat if eating with aligners was proven to speed up treatment.
CONCLUSIONS: Wearing clear aligners while chewing foods such as yogurt, ice cream, soft cheese, bread, rice, etc., can be possible and can help shorten the duration of orthodontic treatment, benefiting both the patient and the orthodontist. However, further research using qualitative methods is needed to understand the barriers and facilitators to chewing food with aligners.

Objectives: Chewing gum has been shown to improve aspects of cognition and mood with sustained attention being particularly receptive to the effects of chewing. Chewing gum may also be a useful vehicle for administering functional ingredients. The herbal extract Rhodiola rosea and certain B-vitamins have previously been shown to improve aspects of cognition and subjective state, but their combined effects have not been studied to date.Methods: The current randomised, placebo-controlled, double-blind, balanced crossover study compared the effects of a functional gum containing Rhodiola rosea and B-vitamins to flavour-matched regular chewing gum and a flavour-matched placebo. Thirty-six healthy young participants completed measures of attention and mood at baseline, during chewing, and 1-h after chewing.Results: Chewing both functional and regular gum was shown to reduce errors on a digit vigilance task compared to placebo irrespective of whether measured during or after chewing. There were no benefits to adding functional ingredients to the gum.Discussion: Future chewing research should consider different formats of placebo. Sex differences in response to chewing and the impact of rate and intensity of chewing should also be explored.Trial registration: ClinicalTrials.gov identifier: NCT05544500.

BACKGROUND: This study aimed to investigate the relationship between an increase in waist circumference (WC) after 1 year and self-reported chewing status in 10,870 Japanese adults who had received health checkups. Subsequently, 8068 participants were included in the final analysis.
METHODS: We defined an increase in WC ≥ 5 cm after 1 year as an unhealthy increase; in total, 613 (7.5%) respondents met this criterion. Chewing status was evaluated using a self-reported questionnaire at baseline; 1080 (13%) respondents were diagnosed with poor chewing status.
RESULTS: After adjusting for age, gender, WC, body mass index (BMI), and chewing status, an increase in WC ≥ 5 cm was found to be positively associated with gender (females: odds ratios [ORs]: 1.206; 95% confidence intervals [CIs]: 1.008-1.443), WC (ORs: 0.967; 95% CIs: 0.954-0.981), BMI (≥25 kg/m2; ORs: 2.194; 95% CIs: 1.715-2.808), and chewing status (poor; ORs: 1.356; 95% CIs: 1.084-1.697).
CONCLUSIONS: These findings suggest that increased WC after 1 year was associated with self-reported poor chewing status in Japanese adults.

Stimulants are the first-line pharmacological treatment for attention deficit hyperactivity disorder (ADHD). We present the unique case of a patient who developed a chewing compulsion when taking mixed amphetamine salts (MAS). A 32-year-old female patient with a past medical history of gastroesophageal reflux disease (GERD), gastroparesis, and migraines was seen for initial psychiatric assessment due to concerns for irritability. She was diagnosed with post-traumatic stress disorder (PTSD); generalized anxiety disorder; ADHD, inattentive type; and unspecified bipolar disorder. Lamotrigine was started and titrated to 25mg twice per day, with improved mood stability. MAS immediate-release (IR) was started at 2.5mg and titrated to 5mg daily for ADHD. She then experienced an uncontrollable urge to chew, finding relief when chewing on a child\'s teething necklace, which provided satisfaction and a reduction in anxiety. She denied jaw tightness or teeth grinding. The dose of MAS IR was reduced to 2.5mg daily with improvement in symptoms and later increased again to 5mg daily, which she was then able to tolerate. Stereotyped biting behaviors have been observed in rats with the use of amphetamines, and the onset of compulsive behavior has emerged in children with the use of dextroamphetamine. However, this is the first known case of compulsive chewing or biting movements reported in humans with MAS use. This case highlights the need to assess patients for adverse events, such as compulsive biting and chewing movements or other oral facial stereotypies, after commencement of stimulants, including MAS.

The masticatory function of patients with skeletal anterior open bite (OPEN) is reported to be impaired compared with that of patients with normal occlusion (NORM). In this study, we compared brain blood flow (BBF) in patients with OPEN and NORM and investigated the factors related to BBF during mastication in patients with OPEN. The study included 17 individuals with NORM and 33 patients with OPEN. The following data were collected: number of occlusal contacts, jaw movement variables during mastication, and BBF measured with functional near-infrared spectroscopy during chewing. The number of occlusal contacts, maximum closing and opening speeds, closing angle, and vertical amplitude were smaller in the OPEN than in the NORM group. Interestingly, BBF increased less in the OPEN group. Correlation analysis revealed that several parameters, including number of occlusal contacts and closing angle, were correlated with changes in BBF during mastication. These results suggest that not only occlusion but also jaw movement variables and factors related to masticatory muscles contribute to the chewing-related increase in BBF. In conclusion, BBF increases less during mastication in patients with OPEN than in those with NORM. In addition, the higher increase in BBF is correlated with jaw movement. Together, we discovered that OPEN exhibits significant adverse effects not only on masticatory function but also on brain function.

Gut peptides play a role in signaling appetite control in the hypothalamus. Limited knowledge exists regarding the release of these peptides in individuals with obesity before and during external stimuli. We hypothesize that the expression of gut peptides is different in the fasting and postprandial states in the scenario of obesity. PubMed/MEDLINE, Scopus, and Science Direct electronic databases were searched. The meta-analysis was performed using Review Manager Software. Randomized controlled trials that measured gut peptides in both obese and lean subjects were included in the analysis. A total of 552 subjects with obesity were enrolled in 25 trials. The gut peptide profile did not show any significant difference between obese and lean subjects for glucagon-like peptide 1 (95% confidence interval [CI], -1.21 to 0.38; P = .30), peptide YY (95% CI, -1.47 to 0.18; P = .13), and cholecystokinin (95% CI, -1.25 to 1.28; P = .98). Gut peptides are decreased by an increased high-fat, high-carbohydrate diet and by decreased chewing. There is no statistically significant difference in gut peptides between individuals with obesity and leanness in a fasting state. However, the release of gut peptides is affected in individuals with obesity following external stimuli, such as dietary interventions and chewing. Further studies are necessary to investigate the relationship between various stimuli and the release of gut peptides, as well as their impact on appetite regulation in subjects with obesity.

This prospective clinical study aimed to assess self-reported orofacial esthetics, chewing function, and oral health-related quality of life (OHRQoL) over three years in the Kennedy Class I patients without posterior dentition who received free-end saddle removable partial dentures (RPDs) retained by two mini dental implants (MDIs) inserted in the canine/first premolar region. The study\'s robust findings reaffirm the viability of MDI-retained RPDs as a treatment modality in contemporary prosthodontics, instilling confidence in the dental community.
METHODS: 92 participants with posterior edentulism in the maxilla or mandible received 184 MDIs and 92 RPDs. After one year, three participants were excluded, and another seven were excluded after three years. The final sample was 82 participants. Self-perceived orofacial esthetics was assessed by the Orofacial Esthetic Scale (OES), chewing function by the Chewing Function Questionnaire (CFQ), and the OHRQoL by the OHIP-14. Statistical analysis utilized multivariate regression analysis, standardized effect size calculation, Wilcoxon Signed Rank test, and Friedman\'s test.
RESULTS: OHRQoL and chewing function significantly improved (p < 0.001) one month after MDI loading by the new RPDs and continued to improve over the observation period (p < 0.05). The OES also significantly improved (p < 0.001) and remained almost unchanged over the next three years (p = 0.440).
CONCLUSIONS: Despite the limitations of this study, the MDI-retained RPD appears to be a viable treatment modality in contemporary prosthodontics from the patients\' perspective.

BACKGROUND: It can be challenging to perform a second task at the same time as swallowing.
OBJECTIVE: The study aimed to investigate the effect of visual, auditory and motor dual-tasking on swallowing and chewing function in healthy young adults.
METHODS: Right-handed healthy adults without any psychological and cognitive problems were included in the study. Swallowing was evaluated based on the dysphagia limit in different liquid textures such as water and nectar consistencies, and chewing was evaluated by the Test of Masticating and Swallowing Solids. For the second task, visual and auditory performance was assessed using reaction time, and the motor performance was assessed using a bilateral tapping task. Assessments were performed in two steps: baseline and dual-task. For baseline, all evaluation methods were applied individually. After completing the baseline assessment, dual-task assessment were carried out the following day. For dual-task assessment, the swallowing and chewing tasks were performed simultaneously with visual, auditory and motor tasks.
RESULTS: Results showed a significant decrease in dysphagia limit in the nectar consistency, and significant increase in chewing time, visual reaction time and tapping rate (right-left) when compared to baseline and dual-task conditions (χ2(3) = 9.61, p = .02; χ2(3) = 9.02, p = .02; χ2(3) = 28.09, p < .001; χ2(3) = 28.97, p < .001; χ2(3) = 21.56, p < .001, respectively). However, there were no differences in dysphagia limit in the water and auditory reaction time compared to baseline and dual-task conditions (χ2(3) = 3.18, p = .36; χ2(3) = 2.56, p = .50, respectively).
CONCLUSIONS: Results shedding light on how simultaneous dual tasks can influence swallowing and chewing. Dual-tasking cause a decrease in both swallowing/chewing and the visual/motor performances. These results may provide valuable information for designing interventions or strategies aimed at improving or maintaining optimal swallowing and chewing during in various populations during daily life.