Adherence to conservative treatments is essential for optimal outcomes in temporomandibular disorder (TMD) patients, yet validated tools for measuring adherence are lacking. This study aimed to develop and validate a bilingual (Arabic-English) questionnaire to comprehensively assess adherence among TMD patients. A cross-sectional, observational, five-phase design was conducted at the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Mansoura University (Egypt). The study included a pilot sample of 60 TMD patients and a psychometric evaluation sample of 300 patients. The exposure was adherence behaviour, measured by a newly developed 50-item, 11-domain adherence questionnaire. The primary outcomes were psychometric properties of the questionnaire, including content validity, internal consistency, test-retest reliability and construct validity. Patient language version (Arabic or English) was considered to examine potential influences on questionnaire performance. Content validity was assessed using Item-Content Validity Index (I-CVI) and Content Validity Ratio (CVR). Reliability was evaluated with Cronbach's α and intra-class correlation coefficient (ICC). Construct validity was examined with exploratory factor analysis (EFA). The final 50-item, 11-domain questionnaire demonstrated strong content validity. Internal consistency was acceptable for both Arabic (Cronbach's α = 0.70) and English (α = 0.68) versions. Test-retest reliability was good (ICC = 0.762-0.898; p < 0.001). EFA confirmed 11 domains, accounting for 61.5% of variance in Arabic and 64.73% in English. The Badawy and Haggag Adherence Questionnaire for TMD demonstrated strong validity and reliability across Arabic and English versions. It provides a robust clinical and research tool for assessing adherence to conservative TMD management, enabling clinicians to identify non-adherence and design tailored interventions to improve outcomes. ClinicalTrials.gov ID NCT07045441. The trial was first posted on 22 June 2025, and the most recent update was posted on 30 June 2025. Retrospectively registered.

Peripheral nerve injury (PNI) often causes persistent sensory and motor deficits because of incomplete axonal regeneration and insufficient remyelination. Schwann cells (SCs) are essential for peripheral nerve repair, but effective recovery depends on their timely transition from a repair state to a myelinating phenotype. To investigate whether KDM2B-PP1, a bioactive peptide designed to disrupt the interaction between lysine-specific demethylase 2B (KDM2B) and enhancer of zeste homologue 2 (EZH2), promotes SC redifferentiation, remyelination, and functional recovery after PNI. Primary rat SCs were treated with KDM2B-PP1 invitro. Myelin-related gene and protein expression were assessed by PCR array, qPCR, Western blotting, and ELISA. The effects of KDM2B-PP1 on SC proliferation, apoptosis, and migration were also examined. A rat facial nerve transection model was used to evaluate the effects of local KDM2B-PP1 administration on remyelination, nerve structure, and functional recovery invivo. KDM2B-PP1 disrupted the KDM2B-EZH2 interaction and relieved EZH2-mediated repression of myelin-related genes. In SCs, KDM2B-PP1 increased the expression of myelin-associated transcripts and proteins, including Olig1, and promoted redifferentiation toward a myelinating phenotype. Invivo, local administration of KDM2B-PP1 enhanced myelin sheath formation, improved nerve architecture, and promoted late-stage functional recovery after facial nerve injury. KDM2B-PP1 did not significantly affect SC proliferation, apoptosis, or migration. KDM2B-PP1 is a novel epigenetic modulator that selectively promotes SC-mediated remyelination and functional recovery after peripheral nerve injury. These findings provide new insight into the epigenetic regulation of peripheral nerve regeneration and support KDM2B-PP1 as a potential therapeutic candidate for PNI.

Guided bone regeneration (GBR) is the most frequently used method for bone augmentation during dental implant surgery. This study was meant to explore the effect of simultaneous GBR on postoperative pain after dental implant surgery. This prospective cohort study included 72 patients who were divided into the following two groups based on whether GBR was performed: Group A (single dental implant placement) and Group B (single dental implant placement with GBR simultaneously). Before the surgery, patients' anxiety status and pain sensitivity were assessed via the State-trait anxiety inventory (STAI) and pain sensitivity questionnaire (PSQ), respectively. The pain values at 2 h, 4 h, 6 h, 24 h, 48 h and 72 h post-operation were recorded using a numerical rating scale. The independent samples t-test was performed to evaluate the difference, and p-values < 0.05 were considered statistically significant. A total of 60 patients completed follow-up, with 30 patients remaining in each group. Patients in Group B experienced moderate pain after the implant surgery, with the peak of pain occurring at 4 h post-operation. And the average pain score in Group B was 4.77, which was higher than that in Group A (2.93). Furthermore, the difference in pain scores between the two groups at 4, 6 and 24 h after surgery was statistically significant (p = 0.002, 0.001 and 0.003, 95% CI = [-2.98, -0.69], [-2.40, -0.67] and [-1.05, -0.22], respectively). Patients undergoing simultaneous GBR during dental implant surgery tend to experience more postoperative pain, reaching up to or exceeding a moderate level. Therefore, we suggest to pay more attention on pain management after dental implant surgery with GBR to improve postoperative comfort. ChiCTR2000041136, https://www.chictr.org.cn/).

The association between masticatory function and osteoporosis is suggestive but inadequately defined. This study examines the association between Functional Tooth Units (FTUs) and osteoporosis. Utilizing data from 9425 U.S. adults aged 50 and older (representing a weighted population of 76 809 922) from the National Health and Nutrition Examination Survey (NHANES; cycles 2005-2010, 2013-2014, 2017-2018), this study employed weighted multivariable logistic regression and restricted cubic splines analyses to examine the association between FTUs and osteoporosis. Subgroup analyses and tests for interaction were employed to investigate potential effect modification and assess the robustness of the observed associations. Sensitivity analysis was conducted to compute E-values for quantifying unmeasured confounding effects and assessing association robustness. Additionally, mediation analysis was conducted to assess the indirect pathways. After adjustment for all covariates, higher FTUs were inversely associated with osteoporosis prevalence (OR = 0.93, 95% CI: 0.89-0.98, p = 0.004). Furthermore, a significant dose-response relationship was observed: participants in the highest FTU tertile (6-8) had a 46% lower risk of osteoporosis compared to those in the lowest tertile (0-1) (OR = 0.54, 95% CI: 0.39-0.76, p < 0.001). Both subgroup and sensitivity analyses confirmed the robustness of these findings. Mediation analysis further revealed that Food Variety Score (FVS) and Geriatric Nutritional Risk Index (GNRI) mediated 7.96% and 6.27% of the association between FTUs and osteoporosis, respectively. This study confirms that better masticatory function, measured by FTUs, is significantly associated with a lower risk of osteoporosis, a link partially explained by improved food variety (FVS) and nutritional status (GNRI). Maintaining adequate masticatory function may therefore be related to a reduced incidence of osteoporosis, possibly through its supportive role in nutritional health. This study highlights the potential of oral health preservation in preventing osteoporosis. Further prospective studies are needed to confirm the causal relationship and optimize clinical intervention.

Bruxism involves involuntary jaw activities like clenching or grinding, linked to changes in temporomandibular joint disorder (TMJ) vibrations, but its independent role is debated. This study used joint vibration analysis (JVA), a non-invasive method, to analyse TMJ vibrations in individuals with potential bruxism. Adults (N = 195), aged 18-45, were included in this retrospective study divided into two groups: those with possible bruxism and TMD features (n = 175) and asymptomatic controls (n = 20). The classification was based on clinical examination and self-report, without differentiating sleep and awake bruxism. TMJ function was evaluated with JVA, assessing peak frequency, median frequency, vibration amplitude, and vibrational energy. Statistical analyses included independent t-tests, Mann-Whitney U tests, Spearman correlation and regression (α = 0.05). Participants with possible bruxism showed higher peak frequency (42.3 ± 5.6 Hz vs. 38.7 ± 4.2 Hz, p = 0.023), median frequency (28.9 ± 4.8 Hz vs. 25.6 ± 3.9 Hz, p = 0.015), vibration amplitude (6.5 ± 1.2 mm/s vs. 4.9 ± 1.0 mm/s, p < 0.001) and vibrational energy (12.7 ± 3.4 μJ vs. 9.2 ± 2.8 μJ, p < 0.001) than controls. Bruxism severity correlated with higher JVA parameters, explaining about 35% of the variance in vibration amplitude and 30% in energy (p < 0.001). Effect sizes ranged from moderate to large (Cohen's d = 0.73-1.35). These results reflect patterns in a mixed bruxism-TMD group, not bruxism-specific effects. Findings show higher TMJ vibrational parameters in those possibly bruxing, many with TMD features. JVA helps characterise TMJ patterns but should not be used alone for bruxism diagnosis without imaging or TMD controls. ClinicalTrials.gov.tr: NCT07070141.

Oral frailty and physical frailty are linked to adverse health outcomes in older adults, but their relationship with sleep quality is not well understood. This study examined the association between oral frailty and sleep quality, and the combined effects of oral and physical frailty on sleep in community-dwelling older adults. A cross-sectional study was conducted in Kaohsiung City, Taiwan (2018-2019), including 1180 adults aged ≥ 65 years selected by multistage stratified cluster sampling. Data were collected through questionnaires and dental exams. Sleep quality was measured by the Pittsburgh Sleep Quality Index. Oral frailty was assessed using indicators such as oral diadochokinesis, swallowing difficulty, masticatory performance, dry mouth, tongue coating, and number of natural teeth. Oral health-related quality of life (OHRQoL) was evaluated with the GOHAI. Logistic regression identified factors associated with poor sleep quality. Swallowing difficulty (AOR = 2.69) and dry mouth (AOR = 2.06) were significantly linked to poor sleep quality. A dose-response relationship was observed across stages of swallowing difficulty, with both suspected and confirmed cases reporting significantly poorer sleep quality compared to individuals without swallowing issues (p for trend < 0.001). Higher OHRQoL scores were linked to better sleep quality (AOR = 0.97). Additionally, the combined presence of oral frailty and physical frailty was significantly associated with poor sleep quality (AOR = 2.71). Oral and physical frailty are significantly associated with sleep quality in older adults. Interventions targeting swallowing difficulty, dry mouth, and physical frailty may improve sleep quality in this population.

The objective of this study was to investigate the prevalence and characteristics of self-perceived swallowing difficulties among community-dwelling older people in South Korea, as distinct from clinically diagnosed dysphagia. A total of 489 community-dwelling, independent older adults (aged ≥ 65 years) were assessed using the Korean version of the Dysphagia Risk Assessment for the Community-dwelling Elderly (K-DRACE), a validated self-report questionnaire. We analysed the perceived frequency of difficulties across the three swallowing phases (oral, pharyngeal and oesophageal). Based on the cut-off score (4 points), the prevalence was calculated. Differences between the no perceived difficulties group and the perceived difficulties group according to participant characteristics were analysed using an independent sample t-test and one-way ANOVA. The prevalence of self-perceived swallowing difficulties among community-dwelling older people in South Korea was 40.7%. The total K-DRACE score increased with age; the oldest group (85+ years) showed the highest prevalence (57.0%) and mean score (4.91 ± 4.22). The highest mean score was observed in the oral phase. Significant differences were found according to gender, education level and residential area. The high prevalence of perceived swallowing difficulties identified in this study, particularly among older adults not clinically diagnosed, underscores the critical need for community-based screening. Identifying this at-risk population through such screening is the essential first step to facilitate timely preventive interventions and ensure referral for further clinical evaluation.

Oral hypofunction (OHF) is a multidimensional condition representing a subclinical decline in oral function. Cross-national comparisons using standardised criteria remain limited. This study aimed to compare the prevalence and characteristics of OHF among community-dwelling adults in Japan and Switzerland and to examine age-related patterns using standardised assessments. A cross-sectional study was conducted in community settings in Japan (153 participants) and in a university dental clinic in Switzerland (117 participants). OHF assessments were performed between May 2023 and January 2024 in Japan and between December 2023 and January 2024 in Switzerland. Data were collected by trained and calibrated examiners from both countries following standardised protocols. OHF was diagnosed when three or more of the seven oral function domains, including oral hygiene, oral dryness, occlusal force, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function, were impaired. Multiple logistic regression analyses were performed with OHF as the outcome after adjusting for country, age, and covariates. Interactions between country and age were also investigated. The prevalence of OHF was 30.7% in Japanese participants and 49.6% in Swiss participants (p = 0.002). The Swiss participants demonstrated significantly better oral hygiene (p < 0.001), while the Japanese participants showed better tongue pressure (p = 0.026), lip-tongue motor function (p < 0.001), maximum occlusal force (p = 0.002), and masticatory function (p < 0.001). In logistic regression, OHF was associated with Swiss nationality (odds ratio [OR]: 3.85, 95% confidence interval [CI]: 1.85-8.00, p < 0.001), age ≥ 70 years (OR: 5.73, 95% CI: 1.67-19.68, p = 0.006, compared to those in their 20s), lower hand grip strength (OR: 0.91, 95% CI: 0.87-0.96, p = 0.001), and fewer teeth (OR: 0.94, 95% CI: 0.89-0.98, p = 0.008). A significant interaction between country and age indicated differing age-related OHF progression between the Japanese and Swiss populations. Both populations exhibited age-related declines in oral function; however, functional impairment was more prevalent and progressive in Switzerland. These findings support the cross-cultural applicability of the OHF criteria and underscore the need for population-specific preventive strategies.

Age-related decline in swallowing function (dysphagia) increases the risk of aspiration pneumonia and reduces quality of life in older adults. However, the efficacy of swallowing-targeted interventions in aging remains unclear. This study aimed to systematically review the interventions for age-related dysphagia in aged rodent models and evaluate their effectiveness through a meta-analysis. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically searched MEDLINE, Embase, and Cochrane Library (January 2024) for studies on interventions for swallowing decline in aged rodents. Seventeen studies were included, of which eight contributed to the meta-analysis. Interventions included progressive resistance tongue exercise, neuromuscular electrical stimulation (NMES), treadmill running, and pharmacological manipulation. The meta-analysis showed that tongue exercise significantly increased in both young (standardised mean difference [SMD] = 3.659; 95% confidence interval [CI]: 2.011-5.308) and aged rodents (SMD = 3.274; 95% CI: 2.682-3.867). Beyond force, tongue exercise improved endurance, induced region-specific myosin heavy chain shifts, and elicited neural and mitochondrial metabolic adaptations. NMES increased fatigue resistance, promoted a shift toward fatigue-resistant fibre isoforms, and partially restored neuromuscular junction integrity. Treadmill running improved endurance and fatigue resistance, with region-dependent effects on fibre composition. Pharmacological interventions had limited impact. Robust evidence shows that progressive resistance tongue exercise can mitigate age-related decline in swallowing, whereas evidence for NMES, treadmill running, and pharmacological interventions remains limited. These findings underscore the translational potential of exercise-based therapies and highlight the need for age-tailored strategies.

The World Health Organization (WHO) defined intrinsic capacity (IC) as the combination of physical and mental resources essential for healthy aging. Currently, the role of oral health in relation to IC remains underexplored. To examine the associations among the number of remaining teeth and IC domains. From the 30 468 subjects of the National Health and Nutrition Examination Survey (NHANES) 2009-2014, we included 787 participants aged ≥ 60 years with available dental/IC-related data, representing a weighted population of approximately 8.35 million U.S. older adults. Dentition status was categorised into four groups: ≥ 20 teeth, 10-19 teeth, 1-9 teeth and edentulous. IC domains (locomotion, vitality, psychological well-being, sensory function and cognition) were operationalised using NHANES items aligned with WHO definitions. Compared with participants with ≥ 20 teeth, those with 10-19 teeth had significantly higher odds of locomotion difficulty [adjusted-odds ratio (OR): 2.18; 95% confidence interval (CI): 1.30-3.66], participants with 1-9 teeth/edentulous also showed an increased risk of locomotion difficulty. The number of remaining teeth was also associated with reduced vitality, particularly unintentional weight loss and lower appetite. Edentulous participants had an increased risk of poor psychological well-being, including depressive symptoms (adjusted-OR: 1.91; 95% CI: 1.22-3.01) and anhedonia (adjusted-OR: 2.27; 95% CI: 1.22-4.24). Significant associations were also found between edentulism and sensory impairments, particularly hearing loss (adjusted-OR: 2.42; 95% CI: 1.17-4.99). The number of remaining teeth in older adults was significantly associated with impairments across multiple IC domains. In particular, reduced dentition (10-19 teeth, 1-9 teeth or edentulism) was consistently linked to impaired locomotion.