Language：English   Publisher：John Wiley & Sons Australia, Ltd  

Language：Japanese   Publisher：Oral Science International  

Purpose: Bisphosphonate-related osteonecrosis of the jaw is thought to be caused by inhibition of osteoclasts, but according to recent research, it has become known that bisphosphonates affect not only osteoclasts but also immune cells and other cells. However, the direct effects of bisphosphonates on the immune system of the mucous membrane covering the bone and oral tissue are not clear. Methods: Using oral mucosal cell lines, we observed the effects of TGF-β released from bone due to osteoclast-mediated bone resorption during tooth extraction on oral mucosal cells in vivo and in vitro. These growth factors promote epithelial–mesenchymal transition (EMT) in oral mucosal cells and induce healing of the extraction site. Results: TGF-β is released from bone due to osteoclast-mediated bone resorption, but bisphosphonates inhibit osteoclast activity, thereby potentially indirectly inhibiting EMT by blocking the activity of the Smad pathway, a downstream target of TGF-β signaling. Additionally, bisphosphonates increase the expression of the autophagy marker Beclin, suggesting the influence of autophagy on bone metabolism. Conclusion: In this study, administering bisphosphonate agents during tooth extraction, particularly during osteoporosis treatment, may prevent the onset of BRONJ by temporarily increasing local TGF-β levels.

DOI： 10.1002/osi2.70025

Scopus

Language：Japanese   Publisher：Japanese Society of Oral and Maxillofacial Surgeons  

Medication-related osteonecrosis of the jaw (MRONJ) is an intractable, progressive, and chronic inflammatory disease. Although oral bacterial infection has been implicated in the development and progression of MRONJ, the causative bacteria remain unclear. As antibacterial agents are frequently used in the treatment of MRONJ, it is necessary to identify the bacterial species and the microbiome that cause MRONJ. We sought to clarify these issues in this investigation of 20 patients diagnosed with MRONJ, 21 patients being treated with a bone-modifying agent (BMA), and 25 healthy individuals as controls. Saliva samples were collected from all participants, and the microbiome was evaluated by a 16SrRNA analysis and next-generation sequencing. A comparative statistical analysis was conducted for each group. In a UniFrac analysis, the diversity of the oral microbiome was significantly lower in the MRONJ and BMA groups compared to the control group. A linear discriminant analysis effect size (LEfSe) analysis identified bacterial species with significantly higher relative abundance in each group. The relative abundance of anaerobic bacteria increased in the order of healthy, BMA, and MRONJ, whereas the detected bacterial species showed a decreasing trend. These results suggest that BMA treatment (<i>i</i>) can be a factor in the relative increase in the levels of anaerobic bacteria and (<i>ii</i>) is a trigger for MRONJ in the oral microenvironment. The dysbiosis of the oral microbiome may begin at the time of BMA introduction. Our results suggest that appropriate oral management during a patient's BMA regimen is important to prevent the development of MRONJ, and that these findings may be useful for the selection of antibacterial agents.

DOI： 10.5794/jjoms.71.556

CiNii Research

Language：Japanese   Publisher：Scientific Reports  

The aim of this study was to analyze the data from a cohort study of community-dwelling older people to clarify the impact of low tongue pressure on the onset of malnutrition. The analysis was divided into a baseline and a longitudinal analysis. The baseline analysis included 765 people (median age: 74 years; 276 men and 489 women), and the longitudinal analysis included 100 people (median age: 72 years; 33 men and 67 women). The baseline analysis showed that tongue pressure and the diagnosis of low tongue pressure using a cut-off of 30 kPa were associated with the risk of malnutrition (tongue pressure: odds ratio [OR] = 0.972, 95% confidence interval [95% CI] = 0.953–0.992, p = 0.006; the diagnosis of low tongue pressure: OR = 1.555, 95% CI = 1.050–2.302, p = 0.027). In the longitudinal analysis, tongue pressure and the diagnosis of low tongue pressure at baseline were associated with the onset of the risk of malnutrition after 4 years (tongue pressure: OR = 0.952, 95% CI = 0.907–0.998, p = 0.041; the diagnosis of low tongue pressure: OR = 2.698, 95% CI = 1.148–6.341; p = 0.023). In community-dwelling older people, low tongue pressure could increase the risk of future malnutrition.

DOI： 10.1038/s41598-025-11229-x

Scopus

PubMed

Language：Japanese   Publisher：(公社)日本口腔外科学会  

2019年4月～2021年4月の薬剤関連顎骨壊死(MRONJ)患者20例(男性15例、女性5例、年齢中央値78歳)、骨修飾薬(BMA)使用MRONJ未発症患者21例(男性18例、女性3例、年齢中央値75歳)、健常者25例(男性11例、女性14例、年齢中央値66歳)の3群を対象とした。唾液のゲノムシーケンスによる細菌叢の構成の解明・LEfSe解析による各群の相対存在量が有意に多い細菌叢の解明を行い、MRONJの原因やリスクとなる口腔細菌叢について検討した。その結果、各群の細菌の相対存在量はBacteroidia属が最多で、次いでFusobacteria網、Betaproteobacteria網で、多様性は健常者群で他の群と有意差があったが、MRONJ群とBMA群の間に有意差は認めなかった。MRONJ群は嫌気性菌の相対存在量が有意に多く、嫌気性への菌性偏位がMRONJのトリガーの一つで、統計学的解析より、MRONJの罹患は口腔細菌の多様性崩壊を起こす可能性が示唆された。

Language：English  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese