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Areca nut is a major contributor to the high prevalence of oral cancer in Asia. The precise mechanisms by which areca nut stimulates mucosal cells and contributes to the progression of oral cancer urgently require clarification. The current study aimed to assess the effects of arecoline on the normal human gingival epithelium cell line S-G. Cell viability, levels of reactive oxygen species (ROS), protein expression, cellular morphology, and gene expression were evaluated using the MTT test, flow cytometry, Western blot analysis, optical or confocal microscopy, and RT-qPCR. Keratin (KRT6) analysis involved matched normal and cancer tissues from clinical head and neck specimens. The results demonstrated that 12.5 µg/mL of arecoline induced ROS production, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) mRNA expression in S-G cells. This activation of the MAPK/ERK pathway increased KRT6 expression while limiting cell migration. In head and neck cancer tissues, KRT6B gene expression exceeded that of normal tissues. This study confirms that arecoline induces ROS accumulation in normal cells, leading to the secretion of proinflammatory factors and KRT6 expression. This impedes oral mucosal healing, thereby promoting the progression of oral cancer. [ABSTRACT FROM AUTHOR]

Statement of Problem: Consideration of the thickness of alveolar bone on both the palatal and labial sides and the inclination angle of teeth is important for immediate implant placement in the maxillary anterior region. However, comprehensive research exploring how sex and age influence the thickness of bone and tooth angle in the maxillary anterior region is lacking., Purpose: The purpose of this clinical study was to investigate the effect of sex and age on the thickness of labial and palatal bone and on the tooth inclination angle of maxillary central and lateral incisors using cone beam computed tomography (CBCT) images in an Asian population., Material and Methods: The labial and palatal bone thickness and the inclination angle of maxillary central and lateral incisors were measured from the CBCT images of 149 participants aged between 20 and 65 years. The correlation between the angles of the maxillary central and lateral incisors and sex and age on the tooth angles and thicknesses of labial and palatal bone was determined statistically., Results: A high correlation (R=0.73) was found between the angle of maxillary central and lateral incisors. Men had higher angles of the maxillary central and lateral incisors and thicker palatal bone at the middle and root of the teeth compared with women. In both sexes, the angle and palatal bone thickness of maxillary central incisors were significantly higher than those of maxillary lateral incisors. The angle of both maxillary central and lateral incisors decreased gradually with age, with a difference in angle of over 10 degrees., Conclusions: The study revealed that women exhibited relatively thinner palatal bone compared with men. Additionally, participants aged between 40 and 65 years exhibited significantly thicker palatal bone compared with younger age groups, potentially providing a larger site for implant placement. Furthermore, tooth angle gradually decreases with age in the maxillary anterior region., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: Finite element analysis and an in vitro experiment were employed to investigate the loading effects of angled abutments, comparing various customized angled abutments derived from the average angle of incisors in patients with a commercial 15°∆ angled abutment, on both the implant and surrounding bone., Methods: Four customized angled abutment models (21.9°∆, 24.15°∆, 20.22°∆, 33°∆) were developed using cone-beam computed tomography (CBCT) images of incisor inclination from various age groups of patients. 3D maxillary bone models were created from CBCT images of four individual patients. Finite element analysis and in-vitro strain gauge experiments were conducted, applying 100N or 50N of axial or oblique force, to assess the differences in stress/strain between the customized and the commercial 15°∆ angled abutments in both the implants and surrounding bone., Results: Under axial loading, the stress values in the dental implant and surrounding bone were elevated due to the relatively higher angles of the customized angled abutments (21.9°∆, 24.15°∆, 20.22°∆, 33°∆) when compared to the commercial 15°∆ angled abutment; however, under oblique loading the commercial 15°∆angled abutment exhibited higher stress values in both the implant and surrounding bone. For in vitro experiment, there is no statically difference in bone strain between the customized (21.9°∆) and the commercial 15°∆ angled abutments in axial loading. Nevertheless, in oblique loading using a commercial 15°∆ angled abutment induced the higher bone strains., Conclusion: Customized angled abutments offer lower stress/strain under oblique loads but higher stress/strain under axial loads compared to commercial ones. Therefore, in the design and application of angled abutments, careful consideration of the occlusal load direction is paramount for achieving biomechanical success of dental implant.

Background: Head and neck cancer survivors suffer from xerostomia and sleep disturbances after radiotherapy, both of which affect their quality of life. This study aimed to explore the role of salivary flow in the oral health and sleep quality of head and neck cancer survivors., Methods: We recruited 120 head and neck cancer survivors who were experiencing symptoms of dry mouth or sleep disturbances post-radiotherapy from a dental clinic. We gathered their socio-demographic and clinical data, measured their salivary flow rate, and recorded their dry mouth score using the summated xerostomia inventory. Additionally, a dentist collected the DMFT (Decayed, Missing, and Filled Teeth) index. The Pittsburgh Sleep Quality Index was employed to assess their sleep quality., Results: In this study, xerostomia was observed in nearly 80% of the cancer survivors. The concurrent prevalence of sleep disturbance and xerostomia was at 55%. After five years post-radiotherapy, there was a significant improvement observed in both the quality of sleep (p = 0.03) and the stimulated salivary flow rate (p = 0.04). Additionally, these improvements were noted to have commenced from the third year onwards. A significant association was found between stimulated salivary flow and dry mouth scores with poor sleep quality (p <  0.05)., Conclusions: We recommend that dental professionals prioritize managing both dental and mental health issues equally for head and neck cancer survivors who have undergone radiotherapy within the past 3 years., (© 2024. The Author(s).)

Background: The anatomical characteristics of the maxillary labial alveolar bone play a crucial role in the treatment planning of immediate implant placement. The sagittal root position (SRP) and alveolar bone concavity are closely related to anatomical characteristics in determining the ideal implant position. This study evaluated the SRP and labial alveolar bone concavity in the maxillary anterior teeth area., Methods: Cone-beam computed tomography images of 120 samples involving 720 teeth were uploaded to the medical imaging software. The SRP was classified as Class I, II, III, or IV, and the concavity of labial alveolar bone was measured. A T test was performed to compare measurements between the central and lateral incisors, between the central incisors and canines, and between the lateral incisors and canine., Results: The majority of the SRPs of the maxillary anterior teeth were class I (engaging the labial cortical plate) with frequencies of 98.3%, 85.8%, and 81.7% for the canines, lateral incisors, and central incisors, respectively. In terms of concavity of labial alveolar bone in maxillary tooth area, canines also had the largest mean value (139.5°), followed by lateral incisors, whereas central incisors has the smallest mean value (131.7°). The results of the T test revealed a significant difference ( p < 0.001) in labial alveolar bone concavity between central and lateral incisors, between central incisors and canines, and between lateral incisors and canines., Conclusion: Most maxillary anterior teeth were classified as Class I SRP, Class III SRP was the least prevalent, and the concavity of the labial alveolar bone significantly differed between the central and lateral incisors, between the central incisors and canines, and between the lateral incisors and canines. In addition, the canines had the highest mean alveolar bone concavity angle, indicating that less concavity in the canines area., Competing Interests: Conflicts of interest: The authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article., (Copyright © 2023, the Chinese Medical Association.)

Background: This study aimed to investigate the risk of stroke incidence in patients with periodontitis., Methods: Data on patients diagnosed with periodontitis were collected from Taiwan's National Health Insurance Research Database and were matched (1:1) with patients without periodontitis between 2001 and 2010. A multivariable Cox survival model was used to predict stroke between patients with and without periodontitis, and the possibility of confounders. Hazard ratios (HRs) with 95% confidence intervals (CIs) were used to explore the risk of stroke in the case and control groups. Diseases found during the follow-up period were analyzed to determine possible effects on the study. A total of 282 560 periodontitis and nonperiodontitis patients were enrolled, with most subjects aged 40 to 59 years., Results: The overall cumulative incidence of stroke was 2.14 times higher in periodontitis than in nonperiodontitis, and the highest HR was in the more than 80 years age group (HR = 9.30; 95% CI, 7.06-12.26). The multivariate Cox model indicated that the adjusted HR (aHR) between the case and control was 2.03 (95% CI, 1.99-2.08), and a higher aHR was associated with hypertension. Atherosclerosis, atrial fibrillation, obesity, kidney disease, anxiety, and gout discovered during follow-up also showed a potential risk of stroke in patients with periodontitis., Conclusion: Therefore, this study suggests a high risk of stroke in patients with periodontitis., Competing Interests: Conflicts of interest: The authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article., (Copyright © 2022, the Chinese Medical Association.)

Clinically, a reconstruction plate can be used for the facial repair of patients with mandibular segmental defects, but it cannot restore their chewing function. The main purpose of this research is to design a new three-dimensionally (3D) printed porous titanium mandibular implant with both facial restoration and oral chewing function reconstruction. Its biomechanical properties were examined using both finite element analysis (FEA) and in vitro experiments. Cone beam computed tomography images of the mandible of a patient with oral cancer were selected as a reference to create 3D computational models of the bone and of the 3D-printed porous implant. The pores of the porous implant were circles or hexagons of 1 or 2 mm in size. A nonporous implant was fabricated as a control model. For the FEA, two chewing modes, namely right unilateral molar clench and right group function, were set as loading conditions. Regarding the boundary condition, the displacement of both condyles was fixed in all directions. For the in vitro experiments, an occlusal force (100 N) was applied to the abutment of the 3D-printed mandibular implants with and without porous designs as the loading condition. The porous mandibular implants withstood higher stress and strain than the nonporous mandibular implant, but all stress values were lower than the yield strength of Ti-6Al-4V (800 MPa). The strain value of the bone surrounding the mandibular implant was affected not only by the shape and size of the pores but also by the chewing mode. According to Frost's mechanostat theory of bone, higher bone strain under the porous implants might help maintain or improve bone quality and bone strength. The findings of this study serve as a biomechanical reference for the design of 3D-printed titanium mandibular implants and require confirmation through clinical investigations.