The loss of teeth is known to influence the mastication of foods and nutritional status. Therefore, we hypothesize that poor dentition status can impair the systemic health of the aged. To clarify the influence of dentition status on deterioration in physical ability, mental impairment, and mortality, we conducted a six-year prospective cohort study of the institutionalized elderly living in 29 of the 30 institutions for the elderly in Kitakyushu, Japan. Bivariate analysis revealed that worse dentition status at baseline led to significantly worse physical and mental impairment, and higher mortality. In a multiple logistic regression analysis, the physical ability of edentulous subjects without dentures significantly deteriorated compared with that of dentate subjects with 20 or more teeth. The six-year mortality rate of the edentulous subjects without dentures was significantly higher than that of the subjects with 20 or more teeth. Poorer dentition status, especially edentulousness without dentures, may therefore be related to deterioration in the systemic health of the aged.

Upper body obesity, related to visceral fat accumulation, is known to increase the risk of various adult diseases, especially type 2 diabetes and cardiovascular disease. This study was conducted to clarify the relationship between upper body obesity and periodontitis. We studied 643 apparently healthy, dentulous Japanese adults who attended programs at Fukuoka Health Promotion Center. Waist-hip ratio, body-mass index (BMI), and body fat were significant risk indicators for periodontitis after adjustment for known risk factors (p < 0.002). Subjects were divided into four BMI (or body fat) categories. In only the subjects with high waist-hip ratio, higher categories of BMI (or body fat) significantly increased the adjusted risk of periodontitis, compared with subjects with low waist-hip ratios and the lowest category of BMI (or body fat). The reported relationship between cardiovascular disease and periodontitis should be reconsidered, since abdominal adiposity or visceral fat can be related to both diseases.

This population-based study determined the salivary microbiota composition of 2,343 adult residents of Hisayama town, Japan, using 16S rRNA gene next-generation high-throughput sequencing. Of 550 identified species-level operational taxonomic units (OTUs), 72 were common, in ≥75% of all individuals, as well as in ≥75% of the individuals in the lowest quintile of phylogenetic diversity (PD). These "core" OTUs constituted 90.9 ± 6.1% of each microbiome. The relative abundance profiles of 22 of the core OTUs with mean relative abundances ≥1% were stratified into community type I and community type II by partitioning around medoids clustering. Multiple regression analysis revealed that a lower PD was associated with better conditions for oral health, including a lower plaque index, absence of decayed teeth, less gingival bleeding, shallower periodontal pockets and not smoking, and was also associated with tooth loss. By contrast, multiple Poisson regression analysis demonstrated that community type II, as characterized by a higher ratio of the nine dominant core OTUs, including Neisseria flavescens, was implicated in younger age, lower body mass index, fewer teeth with caries experience, and not smoking. Our large-scale data analyses reveal variation in the salivary microbiome among Japanese adults and oral health-related conditions associated with the salivary microbiome.The human oral cavity is colonized by numerous and diverse microorganisms as commensals. These bacteria constitute complex microbial communities on intraoral surfaces, and dental plaque microbiota that form on the teeth are the cause of two major oral diseases, dental caries and periodontitis. Mutans streptococci are the major etiologic agent of dental caries 1 and Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola are prime suspects in periodontitis 2 . Furthermore, recent studies that have used open-ended molecular approaches and the 16S rRNA gene have implicated other commensal members with the etiology of each disease, such as lactobacilli for dental caries 3 and as many as 17 species, including Filifactor alosis for periodontitis 4 .Saliva is a biological fluid secreted from the salivary glands into the oral cavity and contains bacteria shed from adhering microbial communities on various intraoral surfaces, including tooth surfaces, gingival crevices, tongue dorsum, and buccal mucosa. Oral bacteria in a planktonic state (as in saliva) are not generally regarded as direct causal agents of the oral diseases. However, intraoral transmission of pathogenic bacteria is likely to be mediated by bacteria dispersed via saliva 5,6 .The salivary microbiome, which is comprised of indigenous bacteria that are specific to each person, exhibits long-term stability (on the scale of years) [7][8][9][10] . On the other hand, oral disorders alter the structure of the teeth and their surroundings. Along with the loss of teeth, tooth decay and its treatment alter the structure of the tooth surfaces on which bacteria are attached. Gingival crevi...

Obesity was associated with deep pockets in Japanese women, even after adjusting for oral glucose tolerance test.

Recent studies have suggested that several systemic conditions--such as obesity, hypertension, hyperlipidemia, and diabetes--are related to periodontitis. The objective of this study was to examine the relationship between periodontitis and 5 components of metabolic syndrome--abdominal obesity, triglyceride level, high-density lipoprotein cholesterol level, blood pressure, and fasting blood sugar level--in 584 Japanese women. In multivariate analyses, persons exhibiting more components of metabolic syndrome had significantly higher odds ratios for a greater pocket depth and clinical attachment loss than did those with no components; the odds ratios for a greater pocket depth and clinical attachment loss of the persons exhibiting 4 or 5 components were 6.6 (95% confidence interval = 2.6-16.4) and 4.2 (95% confidence interval = 1.2-14.8), respectively. These results indicate that metabolic syndrome increases risk of periodontitis, and suggest that people exhibiting several components of metabolic syndrome should be encouraged to undergo a periodontal examination.

1. Malinow MR, Duell PB, Hess DL, et al. Reduction of plasma homocyst(e)ine levels by breakfast cereal fortified with folic acid in patients with coronary heart disease. N Engl J Med 1998;338:1009-15. 2. Savage DG, Lindenbaum J, Stabler SP, Allen RH. Sensitivity of serum methylmalonic acid and total homocysteine determinations for diagnosing cobalamin and folate deficiencies. Am J Med 1994;96:239-46. 3. Herbert V. Making sense of laboratory tests of folate status: folate requirements to sustain normality. Am J Hematol 1987;26:199-207. [Erratum, Am J Hematol 1988;28:134.] 4. Brattstrom LE, Israelsson B, Jeppsson JO, Hultberg BL. Folic acidan innocuous means to reduce plasma homocysteine. Scand J Clin Lab Invest 1988;48:215-21. 5. Santhosh-Kumar CR, Deutsch JC, Ryder JW, Kolhouse JF. Unpredictable intra-individual variations in serum homocysteine levels on folic acid supplementation. Eur J Nutr 1997;51:188-92. To the Editor: The editorial by Oakley (April 9 issue) 1 downplaying the role of dietary modification and advocating routine multivitamin supplementation for the U.S. population illustrates the confusion that exists with respect to the use of nutrient pills as research tools as opposed to an effective public nutrition measure. Furthermore, it contributes to the worrisome U.S. trend toward the medicalization of public nutrition. Nutrient-containing capsules are ideal vehicles for testing diet-health hypotheses, following double-blind, randomized clinical-trial designs. Public nutrition measures in response to these trials should be based first and foremost on dietary recommendations. When diet alone may be insufficient, as for example, in cases of iron deficiency during pregnancy, then carefully targeted supplementation becomes a reasonable option.The New England Journal of Medicine Downloaded from nejm.org on May 11, 2018. For personal use only. No other uses without permission.Copyright © 1998 Massachusetts Medical Society. All rights reserved. · August 13, 19 98The New Eng land Jour nal of Medicine Folic acid supplementation as a public nutrition measure for the prevention of neural-tube defects 2 or heart disease is unwarranted. Contrary to what is implied in the editorial, it is quite possible to obtain recommended intakes of folate or folic acid daily through dietary means, particularly now that flour-based products are fortified with folic acid. Oakley indicates that we have no conclusive evidence on which to base food-based recommendations because studies have used folic acid capsules. The plausibility of this is low, since dietary folate is likely to offer the same benefits as those derived from synthetic folic acid.Oakley's position has major flaws. First, he bases recommendations for the whole United States on studies conducted in samples with unique biomedical, demographic, socioeconomic, and cultural characteristics. Second, there is not a single published randomized trial to support the folic acid-heart disease argument being made. Third, he advocates the use of higher doses for fortificati...

Inflammation is hypothesized to play a significant role in the development of type 2 diabetes; however, reports on clinical inflammatory conditions are limited. Studies have suggested that periodontitis affects glucose control in diabetics. This community-based study examined the relationship between periodontitis and glucose tolerance status, including changes in status. The relationship between periodontal condition and the results of a 75-g oral glucose tolerance test was examined in 961 adults in 1998. Deep pockets (mean pocket depth > 2.0 mm) were significantly associated with impaired glucose tolerance and with diabetes as compared with shallow pockets (< 1.3 mm). In the subgroup with normal glucose tolerance 10 years previously, subjects who subsequently developed impaired glucose tolerance were significantly more likely to have deep pockets. Deep pockets were closely related to current glucose tolerance status and the development of glucose intolerance.

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