Tetrahydrobiopterin (BH4) serves as a cofactor for the activation of tryptophan hydroxylase and nitric oxide (NO) synthase (NOS), which facilitate serotonin synthesis and NO production, respectively. BH4 is rapidly generated from dihydrobiopterin (BH2) and sepiapterin (SP) via intricate enzymatic reactions in the cytoplasm. Recent studies have suggested that serotonin and NO are involved in osteoclast-related bone resorption; however, the precise role of BH4 in osteoclastogenesis remains elusive. To elucidate the effects of BH4, BH2, and SPon RANKL-induced osteoclastogenesis, a comparative study was conducted using macrophage-like RAW264.7 cells. Tartrate-resistant acid phosphatase staining revealed that BH4, BH2, and SP enhanced RANKL-induced multinucleated osteoclast formation. Notably, the intracellular BH4 concentration was significantly elevated in cells treated with SP compared with those treated with BH2 and BH4. Furthermore, N-acetylserotonin, an inhibitor of the conversion of SP to BH4, was used to reduce SP-induced osteoclast formation. Additionally, BH4, BH2, and SP increased the mRNA expression levels of osteoclast markers, including OC- and DC-STAMPs, Cath K, CTR, RANK, Siglec-15, NFκB, and NFATc1, in RANKL-treated cells. However, three distinct NOS inhibitors demonstrated insufficient efficacy in preventing BH4-induced osteoclast differentiation in RANKL-treated cells. Given that BH4, BH2, and SP upregulated the expression of p65, a component of NFκB, but not p52, their potential roles in promoting osteoclast formation in RANKL-treated 264.7 cells may be attributed to the NFκB pathway rather than the autocrine action of BH4-induced serotonin and NO.

Ameloblastoma commonly arise in the mandible and are characterized by local invasiveness and a high recurrence rate. Therefore, accurate assessment of the extent of bony invasion before surgery is critical. However, such assessments rely largely on the experience of radiologists and surgeons, and no objective or reproducible quantitative methods have yet been established. This study aimed to evaluate the clinical utility of relative computed tomography values (rCTv) in determining tumor invasion in ameloblastoma. In this study, six male patients who underwent segmental resection between September 2022 and May 2025 were included. Preoperative computed tomography (CT) images were analyzed using a 3D Slicer to obtain CT values (CTv) from both lesional and non-lesional sites, from whic1h rCTv was calculated. Additionally, clinician-determined CTv and rCTv were derived based on tumor boundaries delineated by eight board-certified oral surgeons, and inter-case variability was analyzed using t-tests. Clinician-determined CTv demonstrated considerable variability across cases, with significant differences in seven out of 15 comparisons. In contrast, the clinician-determined rCTv showed reduced variability, with significant differences observed in only four out of 15 comparisons. The clinical threshold for rCTv was found to lie within the range of 27.83-36.48%. This value obtained in this study can be regarded as a suitable candidate for defining a clinical threshold. This method may serve as an objective reference for determining surgical margins preoperatively and has potential applications as a diagnostic support tool.

This study explored the clinical effect of root canal obturation by vertical condensation in elderly patients with chronic pulpitis. One hundred elderly patients with chronic pulpitis who were treated in our hospital from October 2021 to July 2022 were retrospectively selected as the study subjects, and according to the different treatment methods, they were divided into a study group (n=50, underwent vertical condensation for root canal obturation) and a control group (n=50, underwent cold lateral condensation for root canal obturation). The clinical therapeutic effect of the two groups was compared. The study group had 20 significant effective cases and 29 effective cases, with an overall effective rate of 98.00% (49/50), which was significantly higher than 86.00% (43/50) of the control group (P<0.05). At 3 months and 1 year postoperatively, the study group exhibited significantly lower GI values and periapical radiolucency areas compared to the control group, while demonstrating higher periapical bone density and masticatory function scores (P<0.05). At the 1-year follow-up, the study group showed significantly higher root canal filling densities in the coronal, middle, and apical thirds, as well as the average density, compared to the control group (P<0.05). Postoperative complications in the study group included one case of pain and one case of swelling, with an overall complication rate of 6.00% (3/50), which was not statistically different from the control group’s complication rate of 8.00% (4/50) (P>0.05). Additionally, the study group had significantly higher quality of life scores at 3 months and 1 year postoperatively compared to the control group (P<0.05). Root canal obturation by vertical condensation had a significant therapeutic effect in elderly patients with chronic pulpitis, which was conducive to improving the masticatory function of patients, exhibiting favorable long-term follow-up outcomes, improved quality of life, and a commendable safety.

We aimed to study the therapeutic effects of radial free forearm flap (RFFF) and anterolateral thigh flap (ALTF) repair on oral carcinoma and the complications. The clinical data of 60 oral carcinoma patients undergoing radical resection of oral carcinom from January 2018 to May 2025 were retrospectively collected and analyzed. They were assigned to an RFFF group and an ALTF group. Perioperative indicators, oral function preoperatively and six months postoperatively and quality of life were compared between the two groups. The incidence rates of complications at donor and recipient sites were recorded. The ALTF group had a larger flap area, and longer flap preparation time and operation time than the RFFF group (P<0.05). Six months postoperatively, the accuracy sounds in the Chinese language speech articulation test, and the University of Washington Quality of Life Questionnaire (UW-QOL) scores all increased, while the scores of Standardized Swallowing Assessment (SSA) and Oral Health Impact Profile-14 (OHIP-14) decreased in both groups compared with those preoperatively (P<0.05). The RFFF group had higher accuracy in the Chinese language speech articulation test, and lower SSA scores than the ALTF group (P<0.05). The UW-QOL and OHIP-14 scores were comparable between the two groups (P>0.05). The incidence rates of postoperative complications were similar at the recipient site between the two groups (P>0.05), while it was higher at the donor site in the RFFF group than in the ALTF group (P<0.05). For tissue repair following radical resection of oral carcinoma, RFFF and ALTF are comparable in the efficacy and incidence of postoperative complications at the recipient site, with high flap survival rates and postoperative quality of life. ALTF has lower incidence rate of postoperative complications at the donor site and larger flap areas than RFFF, while RFFF outperforms ALTF in improving speech articulation and swallowing function.

CpG methylation in the upstream region of elongation of very long chain fatty acids-like 2 (ELOVL2) is a robust epigenetic marker associated with chronological age. However, the influence of tobacco smoking on ELOVL2 methylation remains unclear. Therefore, this study aimed to assess the effect of smoking on ELOVL2 methylation and its impact on age estimation accuracy. DNA was extracted from the buccal mucosa of 111 individuals, and ELOVL2 methylation levels were quantified using real-time methylation-specific PCR. Smoking status was determined using a self-administered questionnaire, and individuals were classified into three groups: non-smokers, current smokers, and former smokers. To assess how age, smoking status, and their interaction affect ELOVL2 methylation, a regression model was fitted. ELOVL2 methylation-related differences among the three groups were evaluated using analysis of covariance (ANCOVA), followed by Tukey–Kramer multiple comparisons of age-adjusted ELOVL2 methylation levels. An age estimation model based on ELOVL2 methylation was constructed using data from 51 non-smokers and applied to all three groups to estimate chronological age, followed by a comparison of estimation accuracy among the groups. Regression analysis revealed no significant interaction between chronological age and smoking status, suggesting that age affected ELOVL2 methylation consistently across all groups. ANCOVA revealed that smoking status significantly affected ELOVL2 methylation. Tukey–Kramer multiple comparisons showed that current smokers exhibited significantly higher methylation levels than both non-smokers and former smokers. In contrast, no significant difference was observed between former smokers and non-smokers, suggesting that smoking cessation abolished the effects of smoking on ELOVL2 methylation. Age estimation accuracy did not differ among the three groups. In conclusion, ELOVL2 methylation is influenced by both chronological age and current smoking status; however, smoking status does not impair the accuracy of ELOVL2 methylation-based age estimation. Thus, CpG sites within ELOVL2 remain applicable as predictors for age estimation in forensic medicine.

The accumulation of senescent cells leads to the release of senescence-associated secretory phenotype (SASP) factors that promote inflammation and fibrosis, thereby contributing to the development of age-related disorders. In particular, the age-related decline in salivary gland function causes xerostomia in the elderly, which severely impairs oral hygiene and overall quality of life; however, effective treatments remain unavailable. Human dental pulp stem cells-conditioned medium (hDPSC-CM), which contains anti-inflammatory cytokines and growth factors, has recently attracted attention as a potential anti-aging therapy. In this study, 250 μL of hDPSC-CM was intraperitoneally administered to 79 weeks of age male C57BL/6J mice twice weekly for 4 weeks. Salivary flow, histological alterations, cytokine array profiles, and gene and protein expression levels were evaluated using quantitative real-time PCR and Western blotting. hDPSC-CM treatment significantly increased salivary flow, reduced lymphocytic infiltration, and decreased the expression of aging markers (e.g., p16^Ink4a and p21) and SASP factors. In contrast, the expression of functional markers, stem/progenitor markers, and anti-inflammatory cytokines significantly increased. Consequently, systemic administration of hDPSC-CM may restrain cellular senescence and SASP factor expression, exert anti-inflammatory effects, and promote tissue regeneration and functional recovery in the submandibular glands of aged mice. Therefore, hDPSC-CM may serve as a promising therapeutic approach for age-related salivary gland dysfunction.

This study aimed to evaluate the ability of MetaSEAL Soft Paste, a root canal sealer that has demonstrated favorable sealing performance in dye penetration tests, to prevent bacterial leakage compared with conventional sealers using a novel bacterial leakage test model. MetaSEAL Soft Paste, a methacrylate-based resin sealer, was compared with widely used sealers, including a zinc oxide eugenol-based sealer (Canals), an epoxy resin-based sealer (AH Plus Jet), and a calcium hydroxide-based sealer (Dentalis NX). In the bacterial leakage tests, the mid-root portion of a bovine incisor was horizontally sectioned. The root canal, prepared using a diamond point, was filled with sealer, and the specimen was subsequently placed on a brain heart infusion (BHI) agar. Specimens with a filter paper disc containing Enterococcus faecalis were incubated until bacterial colonization was observed. The antibacterial properties of the sealers were evaluated using the agar diffusion test and the direct contact test. Stable results in the bacterial leakage test demonstrated that this novel model is effective in accurately evaluating the ability of sealers to prevent bacterial leakage. No significant difference was observed in the ability of MetaSEAL Soft Paste to prevent bacterial leakage compared with AH Plus Jet and Canals. In the direct contact test, MetaSEAL Soft Paste and Canals showed significantly fewer bacteria than AH Plus Jet (P < 0.01), indicating higher antibacterial activity. This study suggests that the sealing ability of MetaSEAL Soft Paste was not superior to AH Plus Jet in preventing bacterial leakage, in contrast to the dye penetration test results.