Periodontitis causally affects the brain cortical structure: A Mendelian randomization study.

OBJECTIVE: To estimate whether genetically proxied periodontitis causally impacts the brain cortical structure using Mendelian randomization (MR). BACKGROUND: Periodontitis is one of the most prevalent inflammatory conditions globally, and emerging evidence has indicated its influences on distal organs, including the brain, whose disorders are always accompanied by magnetic resonance imaging (MRI)-identified brain cortical changes. However, to date, no available evidence has revealed the association between periodontitis and brain cortical structures. METHODS: The instrumental variables (IVs) were adopted from previous genome-wide association study (GWAS) studies and meta-analyses of GWAS studies of periodontitis from 1844 to 5266 cases and 8255 to 12 515 controls. IVs were linked to GWAS summary data of 51 665 patients from the ENIGMA Consortium, assessing the impacts of genetically proxied periodontitis on the surficial area (SA) or the cortical thickness (TH) of the global and 34 MRI-identified functional regions of the brain. Inverse-variance weighted was used as the primary estimate; the MR pleiotropy residual sum and outlier (MR-PRESSO), the MR-Egger intercept test, and leave-one-out analyses were used to examine the potential horizontal pleiotropy. RESULTS: Genetically proxied periodontitis affects the SA of the medial orbitofrontal cortex, the lateral orbitofrontal cortex, the inferior temporal cortex, the entorhinal cortex, and the temporal pole, as well as the TH of the entorhinal. No pleiotropy was detected. CONCLUSIONS: Periodontitis causally influences the brain cortical structures, implying the existence of a periodontal tissue-brain axis.

From teeth to brain: dental caries causally affects the cortical thickness of the banks of the superior temporal sulcus.

OBJECTIVES: Dental caries is one of the most prevalent oral diseases and causes of tooth loss. Cross-sectional studies observed epidemiological associations between dental caries and brain degeneration disorders, while it is unknown whether dental caries causally affect the cerebral structures. This study tested whether genetically proxied DMFS (the sum of Decayed, Missing, and Filled tooth Surfaces) causally impacts the brain cortical structure using Mendelian randomization (MR). METHODS: The summary-level GWAS meta-analysis data from the GLIDE consortium were used for DMFS, including 26,792 participants. ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) consortium GWAS summary data of 51,665 patients were used for brain structure. This study estimated the causal effects of DMFS on the surface area (SA) and thickness (TH) of the global cortex and functional cortical regions accessed by magnetic resonance imaging (MRI). Inverse-variance weighted (IVW) was used as the primary estimate, the MR pleiotropy residual sum and outlier (MR-PRESSO), the MR-Egger intercept test, and leave-one-out analyses were used to examine the potential horizontal pleiotropy. RESULTS: Genetically proxied DMFS decreases the TH of the banks of the superior temporal sulcus (BANSSTS) with or without global weighted (weighted, ß = - 0.0277 mm, 95% CI: - 0.0470 mm to - 0.0085 mm, P = 0.0047; unweighted, ß = - 0.0311 mm, 95% CI: - 0.0609 mm to - 0.0012 mm, P = 0.0412). The causal associations were robust in various sensitivity analyses. CONCLUSIONS: Dental caries causally decrease the cerebral cortical thickness of the BANKSSTS, a cerebral cortical region crucial for language-related functions, and is the most affected brain region in Alzheimer's disease. This investigation provides the first evidence that dental caries causally affects brain structure, proving the existence of teeth-brain axes. This study also suggested that clinicians should highlight the causal effects of dental caries on brain disorders during the diagnosis and treatments, the cortical thickness of BANKSSTS is a promising diagnostic measurement for dental caries-related brain degeneration.

Mussel-Based Biomimetic Strategies in Musculoskeletal Disorder Treatment: From Synthesis Principles to Diverse Applications.

Musculoskeletal disorders are the second leading cause of disability worldwide, posing a huge global burden to the public sanitation system. Currently, tissue engineering-based approaches act as effective strategies, which are, however, challenging in limited application scenarios. Mussel-based biomimetic materials, exhibit numerous unique properties such as intense adhesion, biocompatibility, moisture resistance, and injectability, to name only a few, and have attracted extensive research interest. In particular, featuring state-of-the-art properties, mussel-inspired biomaterials have been widely explored in innumerable musculoskeletal disorder treatments including osteochondral defects, osteosarcoma, osteoarthritis, ligament rupture, and osteoporosis. Nevertheless, a comprehensive and timely discussion of their applications in musculoskeletal disorders is insufficient. In this review, we emphasize on (1) the main categories and characteristics of mussel foot proteins and their fundamental mechanisms for the spectacular adhesion in mussels; (2) the diverse synthetic methods and modification of various polymers; and (3) the emerging applications of mussel-biomimetic materials, the future perspectives, and challenges, especially in the area of musculoskeletal disorder. We envision that this review will provide a unique and insightful perspective to improve the development of a new generation of mussel biomimetic strategies.

Helicobacter Pylori - Specific Antigen Tests in Saliva to Identify an Oral Infection.

GOALS: Over the past twenty years, the existence of oral Helicobacter pylori (H. pylori) infection has been controversial and is still disputed. It proposes that living H. pylori do not exist in the oral cavity. However, the progressive loss of efficacy of standard eradication therapies has made the treatment of H. pylori more challenging than ever due to oral H. pylori infection. We conducted a study to explore the existence of oral H. pylori infection among 4321 adults. PROCEDURES: A total 4321 adults (age range, 20-89 years old) comprising 2849 men and 1472 women were recruited by annual physical exam and evaluated using the saliva H. pylori antigen test (HPS) to diagnose oral H. pylori infection and the urea breath test (UBT) to diagnose stomach H. pylori infection. According to the classification on age grouping of World Health Organization, patients were divided into three age groups: A group, the young age subgroup (<45 years); B group, the middle age subgroup (45 to 59 years); C group, the old age subgroup (60-74 years) and D group, the elder subgroup (75-89 years). RESULTS: We found the positive rate of oral H. pylori was 59.59% in the 95% confidence interval (CI) ranges on A group. The lowest positive rate of H. pylori in D group was 25.48% in the 95% confidence interval CI ranges. There was a statistically significant difference (p<0.001) between A, B, C, and D groups but no significant difference between men and women. CONCLUSION: HPS could identify oral H. pylori infection of individuals who have no risk for H. pylori gastric infection. The positive rate of oral H. pylori was 59.59% and this varies across different age groups. This information was not provided by UBT methods. It further identified that the prevalence of oral H. pylori infection is lower in the elder group that may be associated with fewer number of teeth.