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BackgroundThe association between dental status and mortality in community-dwelling older adults has been documented by several studies. The aim of this study was to analyze the contribution of self-assessed chewing ability, number of remaining teeth and serum albumin levels to mortality and the interactions between the three factors.MethodsA 20-year follow-up study was conducted with 666 subjects aged 80 years (from 1996 to 2017) who resided in the 8 areas served by one health center in Iwate Prefecture. Health check-ups including physical fitness measurements were conducted at a meeting place or gymnasium. Medical interview and blood sampling were conducted by physician. Oral examination was examined by dentist. The number of remaining teeth, serum albumin levels, and self-assessed chewing ability were used as predictors of mortality.ResultsAmong the 608 subjects (233 men and 375 women) included in this study, only 12 subjects (1.97%) survived after 20 years of follow-up. For men, dental status and serum levels of albumin were significantly associated with mortality. The hazard ratios of self-assessed chewing ability calculated by item response theory analysis and the inability to chew at least one food adjusted for serum albumin and tooth conditions were statistically significant in men. When adjusted by health status evaluated by blood tests, self-assessed chewing ability was statistically significant in men. According to path analysis, self-assessed chewing ability and serum albumin independently affected mortality in men.ConclusionMasticatory dysfunction may be an important risk factor for mortality in men, even though it was self-assessed. Retaining chewing ability might be a useful predictor of longevity in older male adults.

Quality of life (QOL) and mortality are true endpoints of epidemiological or medical research, especially for community-dwelling older adults. Nutritional status and activities of daily living (ADLs) are associated with QOL and mortality. Good oral health status supports a good nutritional status. The aim of this study was to elucidate the complex structure of these important health-related factors. We surveyed 354 healthy older adults at the age of 85. Nutritional status was evaluated by the serum level of albumin. QOL, ADLs, self-assessed chewing ability, serum albumin level, and mortality during the 15 year follow up period were analyzed. Self-assessed chewing ability was associated with QOL and ADLs. Self-assessed chewing ability for slight-hard foods was associated with mortality in men. However, it was not associated with the serum albumin level. The serum albumin level was associated with mortality in women. These results indicate that maintaining good oral function is not enough. Nutritional instruction in accordance with oral function is indispensable for health promotion in older adults. When planning health promotion strategies for older adults, different strategies are needed for men and women.

Background: Gingival recession and concomitant alveolar bone resorption are hallmarks of periodontal diseases and excessive fluoride intake has some deleterious effects on teeth, bone and soft tissues. Autophagy is a highly conserved intracellular digestion process that degrades damaged proteins and organelles but the biological roles of autophagy in pathological aspects of oral tissues remain largely unknown. We sought to elucidate the function of autophagy, especially its interplay with apoptosis and oxidative stress, in the oral toxicity induced by exposure to 5 mM sodium fluoride (NaF). Methods: HCEM2 cementoblast cells in culture were exposed to 5 mM NaF for 5 min, after which cell viability and cell apoptosis were assessed using the MTS assay and an Annexin V-FITC/PI apoptosis detection kit, respectively. Real-time quantitative RT-PCR and Western blotting were performed to characterize the mRNA and protein expression levels of markers for autophagy, apoptosis, and oxidative stress. C57BL/6 mice were exposed to 5 mM NaF in their drinking water from 12 to 58 weeks. Micro-computed tomography was used to measure changes in their alveolar bone while immunohistochemistry and immunofluorescence staining was used to evaluate protein expression levels of autophagy, apoptosis, and oxidative stress markers.Results: Cementoblasts exposed to 5 mM NaF had decreased levels of autophagy, as shown by reduced expression levels of ATG5, Beclin1 and LC3-II, elicited excessive apoptosis, which in turn induced oxidative stress and inflammation, as manifested by elevated levels of Bax, cleaved caspase-3, SOD1 and phospho NF-κB. Consistently, the in vivo results verified the findings of the in vitro study and treatment of mice with 5 mM NaF resulted in histological abnormalities in periodontal tissues, induced excessive oxidative stress and apoptosis, and reduced autophagy. These results correlated with the immunofluorescence observations, thus confirming the pivotal role of autophagic flux dysfunction in 5 mM NaF-induced cell death. Micro-computed tomography analysis demonstrated that 5 mM NaF caused a decrease in bone areas of mice compared with controls. Exposure to 5 mM NaF induced RANKL (receptor activator of nuclear factor κB ligand) and cathepsin K expression in periodontal tissues, while ATG5 and Beclin1 expression was abrogated by 5 mM NaF.Conclusion: Taken together, our findings suggest that 5 mM NaF elicits oral toxicity that contributes to excessive apoptosis, oxidative stress, and defective autophagy, which aggravates periodontal tissue damage.

The oral microbiome of healthy older adults has valuable information about a healthy microbiome. In this study, we collected and analyzed the oral microbiome of denture plaque and tongue coating samples from four female centenarians. After DNA extraction and purification, pyrosequencing of the V3&ndash, V4 hypervariable regions of the 16S rRNA was carried out. The bacterial taxonomy for each lead was assigned based on a search of the EzBioCloud 16S database. We obtained a total of 199,723 valid, quality-controlled reads for denture plaque and 210,750 reads for tongue coating. The reads were assigned 407 operational taxonomic units with a 97% identity cutoff. Twenty-nine species were detected in both denture plaque and tongue coatings from all subjects. Firmicutes was the most abundant phylum, the Streptococcus salivarius group was the most abundant species in both the denture plaque and tongue coatings, and the Fusobacterium nucleatum group was detected in all subjects. In the bacterial profile, species formed clusters composed of bacteria with a wide range of prevalence and abundance, not dependent on phyla, each cluster may have specific species that could be candidates for a core microbiome. Firmicutes and Veillonella were abundant phyla on both plaque and tongue coatings of centenarians.

Additional file 5: Table S5. Effect of the use of dentures on the mortality of edentulous subjects adjusted by serum albumin levels.

Additional file 2: Table S2. Hazard ratios of health status and chewing ability.

Additional file 1: Table S1. Frequency of subjects who cannot chew each food (A) Frequency of subjects who cannot chew each food.

Additional file 4: Table S4. Item parameter estimates for the 3-parameter logistic model.

Additional file 6: Figure S1. Item response curves for the 15 different types of foods. Figure S2 Survival curves for serum albumin, edentulous/dentulous status and masticatory dysfunction.

Additional file 3: Table S3. Hazard ratios of the self-assessed ability to chew 15 foods.

Background: Chemokines selectively attract and activate leukocytes and play roles in a variety of homeostatic and disease processes. Explore the biological properties of CXCL14 seems complicated due to unknown functional characteristics of CXCL14 in cancer. Methods: To study the multistep process of oral cancer development, we analyzed oral samples spanning normalcy, dysplasia and cancer from multiple perspectives, revealing a cascade of progressive changes. Results: CXCL14 protein was expressed in the cytoplasm adjacent to tumors. T classification (P

Background/aims Lacerations of the oral mucosa and fractures of alveolar processes commonly occur in traumatic dental injuries (TDIs). Impaired wound healing and tissue regeneration have severe consequences on the quality of life. Bone marrow mesenchymal stem cells (BMMSCs) possess the ability of self-renewal and multipotential differentiation. Treatment with low-level sodium fluoride (NaF) has emerged as a promising approach to enhance wound repair. The aim of this study was to assess the effects of low-level NaF on soft tissue healing and on the proliferation, migration and extracellular matrix synthesis of BMMSCs. Material and methods BMMSCs derived from mice were treated with 50 μM, 500 μM, or 5 mM NaF for 12, 24, and 48 hours, and cell proliferation was assessed by the MTS assay. Cell motility was detected at 12 and 24 hours by a wound healing assay, and osteoblastic differentiation for 21 days by 1% Alizarin Red S staining in 50 μM NaF-treated BMMSCs. Gene expression of Runx2 and Osteocalcin was evaluated by quantitative real-time PCR. An experimental rat skin wound model was employed, and levels of c-Myc, Ki67, fibronectin, and vimentin were assessed by immunohistochemistry. Results There was a significant induction in the proliferation and migration of BMMSCs treated with 50 μM NaF. The expression of Ki67 and c-Myc protein was increased in tissues treated with 50 μM NaF, and the expression of fibronectin and vimentin in the 50 μM NaF-treated tissues was stimulated. Alizarin Red staining revealed enhanced mineralization in 50 μM NaF-treated BMMSCs with increased expression of Runx2 and Osteocalcin, indicating their upregulated osteogenic differentiation. Conclusion Low-level NaF could promote soft tissue healing and hard tissue regeneration.

Background and purpose This investigation aimed to establish the basis of a pharmacotherapy for nifedipine-induced gingival overgrowth. Gingival overgrowth has been attributed to the enhanced growth of gingival fibroblasts. In this study, we investigated the effects of 18-α-glycyrrhetinic acid (18α-GA) on growth, the cell cycle, and apoptosis and on the regulators of these processes in gingival fibroblasts isolated from patients who presented with nifedipine-induced gingival overgrowth. Experimental approach Gingival fibroblasts were cultured in medium containing 1% FBS with/without 10 μM 18α-GA for 24 or 48 h, and the cell number, cell cycle phase distribution, relative DNA content, apoptotic cell number and morphological characteristics of the cells undergoing apoptosis were measured together with the levels of proteins that regulate these processes and the level of caspase activity. Key results 18α-GA significantly decreased cell numbers and significantly increased the percentage of cells in the sub-G1 and G0 /G1 phases of the cell cycle and the number of apoptotic cells. Nuclear condensation and fragmentation of cells into small apoptotic bodies appeared in the fibroblasts treated with 18α-GA. In addition, 18α-GA significantly decreased the protein levels of cyclins A and D1, CDKs 2 and 6, phosphorylated Rb (ser(780) and ser(807/811)), Bcl-xL and Bcl-2 and increased the protein levels of p27, cytosolic cytochrome c, pro-caspase-3, and cleaved caspase-3 and the activities of caspases 3 and 9. Conclusions and implications 18α-GA inhibited gingival fibroblast growth by suppressing the G1 /S phase transition and inducing apoptosis. In conclusion, 18α-GA may be used as a pharmacotherapy for nifedipine-induced gingival overgrowth.

Osteoclasts are bone-specific multinucleated cells generated by the differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. Periodontitis is an inflammatory disease characterized by extensive bone resorption. In this study, we investigated the effects of sodium fluoride (NaF) on osteoclastogenesis induced by Porphyromonas gingivalis, an important colonizer of the oral cavity that has been implicated in periodontitis. NaF strongly inhibited the P. gingivalis-induced alveolar bone loss. That effect was accompanied by decreased levels of cathepsin K, interleukin (IL)-1β, matrix metalloproteinase 9 (MMP9), and tartrate-resistant acid phosphatase, which were up-regulated during P. gingivalis-induced osteoclastogenesis. Consistent with the in vivo anti-osteoclastogenic effect, NaF inhibited osteoclast formation caused by the differentiation factor RANKL (receptor activator of nuclear factor κB ligand) and macrophage colony-stimulating factor (M-CSF). The RANKL-stimulated induction of the transcription factor nuclear factor of activated T cells (NFAT) c1 was also abrogated by NaF. Taken together, our data demonstrate that NaF inhibits RANKL-induced osteoclastogenesis by reducing the induction of NFATc1, ultimately leading to the suppressed expression of cathepsin K and MMP9. The in vivo effect of NaF on the inhibition of P. gingivalis-induced osteoclastogenesis strengthens the potential usefulness of NaF for treating periodontal diseases.

Objective In this study, we investigated the role of phenytoin (PHT) in death receptor-induced apoptosis of gingival fibroblasts to clarify the mechanism of PHT-induced gingival overgrowth. Methods Human gingival fibroblasts were cultured to semiconfluence and treated with PHT (0.025, 0.1, 0.25, and 1.0 μM) for 48 h, and then, the apoptotic cell numbers were relatively determined by absorptiometry. After 24 h of 0.25 μM PHT treatment, caspase activity was measured by absorptiometry, apoptotic and cell cycle phase distribution was analyzed by flow cytometry, expression levels of apoptotic genes were quantified by real-time qPCR, and expression of apoptotic proteins was detected by Western blot analysis. After 48 h of 0.25 μM PHT treatment, appearance of apoptotic cells was detected by TUNEL assay. Results PHT treatment decreased the proportion of apoptotic cells in gingival fibroblasts compared to a serum-free control culture in response to the protein changes as follows: PHT upregulated c-FLIP and, in turn, downregulated FADD, caspase-8, and caspase-3; PHT upregulated c-IAP2 and downregulated TRAF2; PHT downregulated caspase-9 and caspase-3 via decreased RIPK1 activity and increased Bcl-2 activity. Conclusion PHT-induced gingival overgrowth may result from the above-mentioned mechanisms involving apoptosis inhibition in gingival fibroblasts.

The purpose of the present study was to determine whether different consistency of diet and malocclusion induced by the extraction of molar teeth on the masticatory organs modulated gastric acid secretion, gastric emptying and intestinal transit in young and elder rats. Male Wistar rats (young, 5weeks; elder, 1.5years) were used in this experiment, and were divided into 2 groups. Group one (G1) was maintained with solid diet, Group two (G2) with mud diet. Further, the mandibular molar teeth of G2 were extracted. The experimental period was 10weeks. The effect of aging and malocclusion on the parameters of gastric secretion was examined using pylorus-ligated rats. The gastric emptying rate (GER) and small intestinal transit rate was determined in rats by evans blue from the stomach and charcoal from the small intestinal, respectively. In pylorus-ligated rats, Young-G2 rat of gastric juice volume, acid output and pepsin secretion remarkably showed significant decrease in comparison with Young-G1 group, but there was not significant difference between Elder-G1 and Elder-G2. GER of Young-G2 rat group was 44.2±7.9%, significantly lower than that of Young-G1 rat group (61.6±8.8%, P

14 To examine possible association between dental amalgam fillings and mercury burden, we measured the mercury concentrations in scalp hair samples from 74 female Japanese subjects aged 26-64 years who had a dietary habit of little fish-consumption. The hair mercury concentrations in the subjects with multiple amalgam fillings were significantly higher than those in the subjects with no amalgam fillings, and correlated with the number of amalgam fillings in the following regression equation: log Hg = 0.084 amalgam fillings + 3.377 (r = 0.339, p = 0.003). In addition, multiple regression analysis demonstrated that the hair mercury concentrations were significantly correlated with the amalgam fillings (r = 0.292; p = 0.014) and age (r = 0.284; p = 0.017) but not significantly with the body mass index (r = 0.060). A regression equation of log Hg = 0.071 amalgam fillings + 0.011 age + 0.006 BMI + 2.72 was obtained (r = 0.447), with 0.200 of the determination coefficient. These findings suggest that the dental amalgam fillings positively influence mercury accumulation in the hair and also, probably, in the body. Abstract Koufuchi Ryo 1), Atsuko Ito 1), Rie Takatori 1), Yoshinori Tai 2), Junji Tokunaga 1), Kazumune Arikawa 2), Takashi Yamada 1), Keiko Shinpo 1), Hiroshi Yasuda 3), Ichiro Saito 1)

As members of the Organization of International Support for Dental Education (OISDE) , we had been implementing“the project of primary health care and prevention of systemic damages caused by peri-odontal infection at the rural area in the Kingdom of Cambodia”. This project was supported by Japan International Cooperation Agency (JICA) since March 2004 until March 2005. The targeted areas were composed of 7 provinces and 25 districts. The subjects were 1,296 residents. As one of the risk factors, living environment risk (LE) factor was charted based on a five-grade method according to our original classification. Systemic medical condition of the residents was charted by interview method into history of systemic diseases and history of tropical infections. The dental intelligence quotient (dental IQ) concerning periodontal infection was charted by question and answer method according to a five-grade classification. As part of behavioral risk factor for periodontal inflammation, the number of frequency of brushing the teeth was evaluated using interview method. The level of periodontitis was evaluated by periodontal probing using the four-point method and bleeding on probing (BOP) for all remaining tooth/teeth in each resident. The medical examination, which includes heart murmurs, lung sounds, blood pressure, urine test, and electrocardiogram (ECG) , was investigated by a physician. In the result, 29% of the residents were discovered with abnormal heart murmur or ECG findings. These comprised 34% mitral valve murmur, 18% tricuspid valve murmur, and 16% other abnormal heart sounds. The ECG findings in the residents with abnormal heart findings revealed 23% due to premature atrial contraction, 14% atrio-ventricular (A-V) Block, and 6% was caused by other abnormal ECG findings. The onset of heart disease was statistically different between the group with over 3.5 mm depth and the group with less than 2 mm depth when analyzed by t-test. In spite of the heart disease was detect in no BOP group of 20%, the heart disease was significantly tendency by statically analyze increasing according to over 20% of BOP. This result strongly considered that chronic periodontal inflammation has one of the caused damages to the heart valves and is influenced by bacteremia. Nihon Shishubyo Gakkai Kaishi (J Jpn Soc Periodontol) 48 : 208-217, 2006.

There have been many studies on the relationships among various methods for determining whole salivary volume and these methods' effectiveness. The methods of determining this volume include those that determine the salivary volume of a subject at rest and during salivary stimulation. The convention method uses both the spitting method at rest and the paraffin mastication method. In the present study, we compared the reproducibility of the salivary volumes determined by the modified ion dilution method (the modified fluoride dilution method) and conventional methods. Salivary volumes in decreasing order were sour stimulation with the modified fluoride dilution (MFD) method, during mastication, under tasteless stimulation with the MFD method, and at rest. Higher correlations were found between the salivary volumes at rest and during mastication determined by the conventional method (r=0.57, p

In the current study, we used the modified ion dilution method to evaluate the influence of the circadian rhythm on the salivary volume in response to varying sour concentrations. We found that the salivary volume changed depending on when the sample was taken and on the sour concentration. Specifically, there was a definite trend for the salivary volume to be low in the morning and to increase from around lunchtime to evening. In addition, the influence of the circadian rhythm on salivary volume tended to be reduced by a strong taste stimulation (high sour concentration). These results suggest that the greater the amount of stimulation (sour stimulation), the smaller the effect of circadian rhythm on the salivary volume.

Objectives Dry mouth is a condition associated with reduced salivary secretion and is thought to be related to aging. This study was conducted to test whether reduced (ubiquinol) or oxidized (ubiquinone) forms of CoQ10 affect salivary secretion and salivary CoQ10 content before and after treatment. Design and methods Sixty-six patients were given either ubiquinol or ubiquinone orally at a dosage of 100 mg/day, or a placebo for 1 month, and salivary secretion and salivary CoQ10 content were analyzed before and after treatment. Results Both parameters were significantly improved following treatment with either form of CoQ10, suggesting the effectiveness of CoQ10 in attenuating dry mouth symptoms. Conclusion CoQ10 was locally detected in salivary glands, suggesting that orally administered CoQ10 was transported to the salivary glands via the blood stream and exerted its activity, improving salivary secretion.