Preterm low birth weight and periodontal disease among African Americans

Periodontal Disease and Pregnancy: Correlation with Underweight Birth

Periodontal disease is a risk factor for many systemic diseases including preterm birth and underweight birth. The purpose of this systematic review is to analyze the literature and to highlight any clinical correlation. Information sources such as PubMed, MEDLINE, and Web of Science were consulted to obtain our results with these keywords "periodontal disease," "pregnancy," "weight loss" using the connector "AND." After the first screening by authors, only 27 articles were included in this review. From the analysis of the literature, it was noted that the presence of periodontal disease could have a correlation with underweight birth. Surely, control oral hygiene and oral health is essential during pregnancy to reduce risks, and these results should be essential in establishing a protocol to be maintained during pregnancy.

Tryptophanyl tRNA Synthetase from Human Macrophages Infected by Porphyromonas gingivalis Induces a Proinflammatory Response Associated with Atherosclerosis

Porphyromonas gingivalis is the most common microorganism associated with adult periodontal disease, causing inflammation around the subgingival lesion. In this study, we investigated tryptophanyl tRNA synthase (WRS) production by THP-1 cells infected with P. gingivalis. Cytokine production, leukocyte adhesion molecules, and low-density lipoprotein receptor (LDLR) expressions in cultured cells were examined. WRS was detected in THP-1 cell culture supernatants stimulated with P. gingivalis from 1 to 24 h, and apparent production was observed after 4 h. No change in WRS mRNA expression was observed from 1 to 6 h in THP-1 cells, whereas its expression was significantly increased 12 h after stimulation with P. gingivalis. Lactate dehydrogenase (LDH) activity was observed from 4 to 24 h. The TNF-α, IL-6, IL-8, and CXCL2 levels of THP-1 cells were upregulated after treatment with recombinant WRS (rWRS) and were significantly reduced when THP-1 cells were treated with C29. The MCP-1, ICAM-1, and VCAM-1 levels in human umbilical vein endothelial cells were upregulated following treatment with rWRS, and TAK242 suppressed these effects. Additionally, unmodified LDLR, macrophage scavenger receptor A, and lectin-like oxidized LDLRs were upregulated in THP-1 cells treated with rWRS. These results suggest that WRS from macrophages infected with P. gingivalis is associated with atherosclerosis.

Infection and atherosclerosis: TLR-dependent pathways

Atherosclerotic vascular disease (ASVD) is a chronic process, with a progressive course over many years, but it can cause acute clinical events, including acute coronary syndromes (ACS), myocardial infarction (MI) and stroke. In addition to a series of typical risk factors for atherosclerosis, like hyperlipidemia, hypertension, smoking and obesity, emerging evidence suggests that atherosclerosis is a chronic inflammatory disease, suggesting that chronic infection plays an important role in the development of atherosclerosis. Toll-like receptors (TLRs) are the most characteristic members of pattern recognition receptors (PRRs), which play an important role in innate immune mechanism. TLRs play different roles in different stages of infection of atherosclerosis-related pathogens such as Chlamydia pneumoniae (C. pneumoniae), periodontal pathogens including Porphyromonas gingivalis (P. gingivalis), Helicobacter pylori (H. pylori) and human immunodeficiency virus (HIV). Overall, activation of TLR2 and 4 seems to have a profound impact on infection-related atherosclerosis. This article reviews the role of TLRs in the process of atherosclerosis after C. pneumoniae and other infections and the current status of treatment, with a view to providing a new direction and potential therapeutic targets for the study of ASVD.

OmpA-Like Proteins of Porphyromonas gingivalis Mediate Resistance to the Antimicrobial Peptide LL-37

Subgingival bacteria are continually exposed to gingival crevicular fluids that are derived from serum, which contain various bactericidal agents. The periodontopathic bacterium Porphyromonas gingivalis has been demonstrated to possess a variety of abilities to resist bactericidal agents, due to which it is able to propagate in the subgingival environment. We previously demonstrated that the major surface glycoproteins of P. gingivalis—Pgm6 and Pgm7, also called outer membrane protein A-like proteins (OmpALPs)—mediate resistance to the bactericidal activity of human serum, but their precise role remains unknown. In this study, we investigated the sensitivity of the wild-type and Pgm6/Pgm7-deficient P. gingivalis strains toward major antimicrobial peptides in the oral cavity, human β-defensins (hBDs) 1-3, and human cathelicidin LL-37. hBDs showed a considerably weak bactericidal activity against both bacterial strains. LL-37 also showed a weak activity against the wild-type strain; however, it showed a significant activity against the Pgm6/Pgm7-deficient strain. In the Pgm6/Pgm7-deficient strain, LL-37 remarkably accumulated on the bacterial cell surface, which may result in the destruction of the outer membrane. Additionally, the bactericidal activity of hBDs against the Pgm6/Pgm7-deficient strain was found to be synergistically promoted in the presence of LL-37. Our results suggest that OmpALPs specifically protect P. gingivalis from the bactericidal activity of LL-37; thus, P. gingivalis may adeptly survive in LL-37-producing subgingival environments.

OmpA-like proteins of Porphyromonas gingivalis contribute to serum resistance and prevent Toll-like receptor 4-mediated host cell activation

Porphyromonas gingivalis possesses various abilities to evade and disrupt host immune responses, by which it acts as an important periodontal pathogen. P. gingivalis produces outer membrane protein A (OmpA)-like proteins (OmpALPs), Pgm6 and Pgm7, as major O-linked glycoproteins, but their pathological roles in P. gingivalis infection are largely unknown. Here, we report that OmpALP-deficient strains of P. gingivalis show an enhanced stimulatory activity in coculture with host cells. Such an altered ability of the OmpALP-deficient strains was found to be due to their impaired survival in coculture and the release of LPS from dead bacterial cells to stimulate Toll-like receptor 4 (TLR4). Further analyses revealed that the OmpALP-deficient strains were inviable in serum-containing media although they grew normally in the bacterial medium. The wild-type strain was able to grow in 90% normal human serum, while the OmpALP-deficient strains did not survive even at 5%. The OmpALP-deficient strains did not survive in heat-inactivated serum, but they gained the ability to survive and grow in proteinase K-treated serum. Of note, the sensitivity of the OmpALP-deficient strains to the bactericidal activity of human β-defensin 3 was increased as compared with the WT. Thus, this study suggests that OmpALPs Pgm6 and Pgm7 are important for serum resistance of P. gingivalis. These proteins prevent bacterial cell destruction by serum and innate immune recognition by TLR4; this way, P. gingivalis may adeptly colonize serum-containing gingival crevicular fluids and subgingival environments.

Periodontal Disease and Prematurity among Non-smoking Sri Lankan Women

The hypothesis that periodontal disease is associated with pre-term low birthweight was tested in a prospective follow-up study of rural prima-gravida women (N = 227) who were free of tobacco, alcohol, and drug use. Women with 3rd trimester mean probing pocket depths, plaque, and bleeding scores that were greater than the median value in the cohort were defined as ‘exposed’. There were 17 (7.5%) preterm low birthweight singleton deliveries in the cohort (among ‘exposed’ = 12%; among ‘unexposed’ = 5.6%; Odds Ratio = 2.3; 95% CI = 0.9−6.3). After adjustment for the independent variables, the OR for preterm low birthweight in relation to ‘exposure’ was 1.9 (95% CI = 0.7−5.4). Our results are only suggestive of an association between periodontal disease and preterm low birthweight, perhaps indicating that previously reported associations may have been subjected to residual confounding due to tobacco, alcohol, and drug use.

Comparative Evaluation of Oral Health Knowledge, Practices and Attitude of Pregnant and Non-Pregnant Women, and Their Awareness Regarding Adverse Pregnancy Outcomes

BACKGROUND

Adverse pregnancy outcomes are undesirable events occurring during pregnancy and childbirth in mother or child, such as Preterm Low Birth Weight (PLBW) and preeclampsia. There is growing evidence that periodontitis may be a risk factor for preterm birth even after adjusting for known risk factors.

AIM

1. To determine the knowledge and attitude of pregnant females about oral health. 2. To evaluate the oral hygiene practices of pregnant females. 3. To evaluate their awareness regarding effect of oral health on adverse pregnancy outcomes. 4. To assess whether there was any significant difference from their non pregnant counter parts. 5. To evaluate whether their awareness towards dental treatment had increased after conceiving.

MATERIALS AND METHODS

200 pregnant and 200 non-pregnant women filled up a validated questionnaire which comprised of questions on personal data, oral hygiene knowledge, attitude, oral hygiene practices and their awareness regarding the correlation of oral health to adverse pregnancy outcomes.

STATISTICAL ANALYSIS

Analyses were conducted using SPSS for Windows (version 15.0; SPSS Inc., Chicago, IL, USA).

RESULTS

The results indicate no statistically significant differences in the variables assessed in both the groups, indicating that no further knowledge had been imparted to the women after they conceived. 96% women of both groups (p>0.05) had received no knowledge from the gynaecologist regarding the impact of oral health on pregnancy outcomes. 93.9% of pregnant women, and 89.5% of non pregnant women (p>0.05) did not go for routine dental check-ups. Only 3% of pregnant women were aware of oral health having a correlation with adverse pregnancy outcomes.

CONCLUSION

In our study, pregnancy did little to change future attitudes to dental care. To provide better oral health care, more knowledge needs to be made available to the pregnant women and the medical community.

Periodontal innate immune mechanisms relevant to atherosclerosis

Atherosclerosis is a common cardiovascular disease in the USA where it is a leading cause of illness and death. Atherosclerosis is the most common cause for heart attack and stroke. Most commonly, people develop atherosclerosis as a result of diabetes, genetic risk factors, high blood pressure, a high-fat diet, obesity, high blood cholesterol levels, and smoking. However, a sizable number of patients suffering from atherosclerosis do not harbor the classical risk factors. Ongoing infections have been suggested to play a role in this process. Periodontal disease is perhaps the most common chronic infection in adults with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between periodontal infection and atherosclerosis. This review focuses on exploring the molecular consequences of infection by pathogens that exacerbate atherosclerosis, with the focus on infections by the periodontal bacterium Porphyromonas gingivalis as a running example.

Is there a relationship between maternal periodontitis and pre-term birth? A prospective hospital-based case-control study

OBJECTIVE

The aim of this study is to verify the existence of an association between maternal periodontal disease and pre-term delivery in an unselected population of post-partum Turkish women.

MATERIALS AND METHODS

This case-control study was conducted on 100 women who gave birth in either a special or a government maternity hospital. The case group consisted of 50 mothers who had delivered an infant before 37 weeks' gestation and weighed under 2500 g. The control group included 50 mothers who had given birth to an infant with a birth weight of more than 2500 g and a gestational age of ≥37 weeks. Data of mothers and infants were collected using medical registers and questionnaires. Clinical periodontal examinations were carried out in six sites on every tooth in the mother's mouth. A participant who presented at least four teeth with one or more sites with a PPD ≥4 mm and CAL ≥3 mm at the same site was considered to have periodontal disease. Statistical methods included parametric and non-parametric tests and multiple logistic regression analysis.

RESULTS

There were no statistically significant differences between the cases and controls with regard to periodontal disease and pre-term delivery (OR = 1.48; 95% CI = 0.54-4.06).

CONCLUSION

The findings indicated that maternal periodontitis was not a possible risk factor for pre-term delivery. Further studies with additional clinical trials are needed to explore the possible relationship between periodontal disease and pre-term birth.

Evaluation of socio-demographic variables affecting the periodontal health of pregnant women in Chandigarh, India

Background:

The literature is replete with reports that pregnant women have an increased level of periodontal disease as compared with non-pregnant women of the same age. There are many studies correlating the effect of periodontal disease on the adverse pregnancy outcomes. The development of periodontal diseases during pregnancy can be influenced by factors such as preexisting oral conditions, general health, and socio-cultural background. There is very little data studying the effect of socio-demographic factors on the periodontal health of pregnant women. This study evaluated the periodontal status of a sample of pregnant women of Chandigarh and adjoining areas. The study also investigated the relationship between these variables and a series of demographic and clinical variables.

Materials and Methods:

The participants were 190 pregnant women attending Gynecology and Obstetrics outpatient department of Government Medical College and Hospital, Chandigarh. The participants were examined for their periodontal health and various socio-demographic variables were recorded on performas designed for the purpose of study. Statistical analysis was done.

Results:

The results revealed that the mean bleeding index scores and probing depth increased with statistical significance when the socio-economic status was lower (P<0.05). No significant differences were found in bleeding index scores and mean probing depth among different categories of profession, education, place of residence, and trimester of pregnancy (P>0.1). The plaque index was not significantly associated with the socio-economic status, profession, place of residence, and trimester of pregnancy (P>0.1).

Conclusion:

In the population of pregnant women investigated under this study, the clinical and socio-demographic characteristics showed non-significant correlation except socio-economic status which showed statistically significant correlation with bleeding on probing and pocket depth. Further studies may be required in Indian population to determine the association of periodontal diseases in pregnant women with socio-demographic variables.

Association between MMP-1 g.-1607dupG polymorphism and periodontitis susceptibility: a meta-analysis

Background

Matrix metalloproteinase-1 (MMP-1) plays an important role during the destruction of periodontal tissue. Although multiple studies had focused on the association between MMP-1 g.-1607dupG and periodontitis susceptibility, the results remained inconclusive. The purpose of this meta-analysis was to explore its role in the development of periodontitis.

Methods

Retrieved studies from Pubmed, Web of Science, Medline and Google Scholar Search regarding MMP-1 g.-1607dupG and periodontitis susceptibility were included into the final analysis with definite selection and exclusion criteria. Overall and stratified analyses based on disease type, severity, ethnicity and smoking status were performed. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between MMP-1 g.-1607dupG and periodontitis susceptibility, while Q test and Egger’s test were adopted respectively to assess heterogeneity among studies and publication bias.

Results

A total of 1580 periodontitis cases and 1386 controls in 11 case-control studies were included in the meta-analysis. The pooled results showed significant association between periodontitis susceptibility and MMP-1 g.-1607dupG polymorphism in homozygote (2G/2G versus 1G/1G, OR = 1.50, 95% CI = 1.02–2.20) and dominant model analysis (2G/2G+2G/1G versus 1G/1G, OR = 1.28, 95% CI = 1.04–1.57). For subgroups by type of periodontitis, increased risk of chronic periodontitis was observed on heterozygote (2G/1G versus 1G/1G, OR = 2.01, 95% CI = 1.58–2.56) and dominant model (OR = 1.27, 95% CI = 1.03–1.57). Furthermore, similar association was also detected in severe chronic periodontitis (2G/2G versus 1G/1G, OR = 2.15, 95% CI = 1.35–3.43; 2G/2G+2G/1G versus 1G/1G, OR = 1.64, 95% CI = 1.12–2.39; 2G/2G versus 2G/1G+1G/1G, OR = 1.86, 95% CI = 1.31–2.64).

Conclusions

Our meta-analysis demonstrated that MMP-1 g.-1607dupG polymorphism was associated with chronic periodontitis, especially the severity of the disease condition.

The sinR ortholog PGN_0088 encodes a transcriptional regulator that inhibits polysaccharide synthesis in Porphyromonas gingivalis ATCC 33277 biofilms

Biofilm-forming cells are distinct from well characterized planktonic cells and aggregate in the extracellular matrix, the so-called extracellular polymeric substances (EPS). The sinR gene of Bacillus subtilis encodes a transcriptional regulator that is known to be involved in the biosynthesis of EPS in biofilms. Porphyromonas gingivalis inhabits the subgingival and extraradicular biofilm of humans and is one of the primary pathogens that cause progressive marginal and refractory apical periodontitis. Furthermore, P. gingivalis possesses PGN_0088, which encodes a putative ortholog of B. subtilis sinR. Here, we investigated the role of PGN_0088 (sinR) on biofilm formation. P. gingivalis strains formed biofilms on saliva-coated glass surfaces in phosphate buffered saline. Quantitative analysis indicated that the biofilm of the sinR null mutant consisted of dense exopolysaccharide. Microscopic observations showed that the increased levels of exopolysaccharide produced by the sinR mutant changed the morphology of the EPS to a mesh-liked structure. Furthermore, physical analyses suggested that the enrichment of exopolysaccharide in the EPS enhanced the resistance of the biofilm to hydrodynamic shear force. The results presented here demonstrate sinR plays important roles in the ability of P. gingivalis strain ATCC 33277 to act as a negative mediator of exopolysaccharide accumulation and is indirectly associated with the structure of the EPS and the force of its adhesion to surfaces.

Relationship between maternal periodontal disease and Apgar score of newborns

Purpose

The aim of this study was to evaluate the relationship between maternal periodontal disease and the health status of newborns using Apgar scores.

Methods

One hundred pregnant women with periodontal disease were included in the case series and 100 pregnant women without periodontal disease were placed in the control group, respectively. The periodontal parameters of bleeding on probing (BOP), clinical attachment loss (CAL), probing depth (PD), birth weight, and Apgar scores were recorded in both groups. T-tests and Pearson's correlation coefficient were used to determine the birth weight odds ratio to analyze the relationship between the periodontal parameters of BOP, CAL, and PD on the one hand and an Apgar score of less than 7. An unpaired Student's t-test was used to analyze differences in means between the case and control groups using SPSS ver. 13.

Results

The means of the ages, periodontal pocket depths, attachment loss, areas with BOP, Apgar score in the first 5 minutes and infant birth weight exhibited statistically significant differences between the case and control groups. The ratio of an Apgar score of <7 to periodontal disease was 3.14; the ratio of low birth weight risk in mothers with periodontal disease to that in mothers without periodontal disease was 2.74. Pearson's correlation coefficient revealed a significant correlation between the infant birth weight and BOP, CAL, and PD of the mother. In addition, there was a significant correlation between the Apgar score and BOP, CAL, and PD and also between the Apgar score and infant birth weight.

Conclusions

The results of this study showed a significant relationship between periodontal disease and infant birth weight; in addition, there was a significant relationship between the periodontal indexes of BOP, CAL, and PD on the one hand and the Apgar score on the other.

Lack of association between maternal periodontal status and adverse pregnancy outcomes: a multicentric epidemiologic study

OBJECTIVE(S)

The aim of this study was to explore the relationship between periodontal health and pregnancy outcomes in a large cohort of Italian postpartum women.

METHODS

750 postpartum women were enrolled in a case-control study within 5 days from delivery at three Italian obstetric clinics. Cases were defined as those mothers who delivered an infant weighing under 2500 g (LBW) and/or had premature delivery and/or delivered small for gestational age newborns (SGA) and/or experienced preeclampsia/pregnancy induced hypertension (PE/PIH) or preterm premature rupture of membranes (pPROM) during pregnancy. All women received comprehensive oral and dental examination. Associations between adverse pregnancy outcome and exposures of interest were evaluated by the use of multivariate logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

There was no significant difference between cases and controls with respect to country of birth, age, place of residence, educational achievement, smoking, and periodontal status. By definition, infant birth weight [2,750 g (IQR = 2,300-3,200 g) and 3,275, (IQR = 3,010-3,538 g) p < 0.001, respectively] and gestational age at delivery [259 days (IQR = 245-273) and 273 days (IQR = 266-280), p < 0.01, respectively] were significantly lower in cases than in controls. In multivariate analyses, a borderline association was found between poor obstetric outcomes and current smokers (OR: 1.5; 95% CI: 0.1-2.5). Finally, after adjusting for smoking status neither country of birth, nor age or place of residence or education or periodontitis were associated with a significantly increased risk of adverse pregnancy outcome.

CONCLUSION(S)

Our data failed to demonstrate the association between periodontitis and an adverse pregnancy outcome such as preterm birth, low birth weight, preeclampsia, intrauterine growth restriction, and premature rupture of membranes.

Protective role for TLR4 signaling in atherosclerosis progression as revealed by infection with a common oral pathogen

Clinical and epidemiological studies have implicated chronic infections in the development of atherosclerosis. It has been proposed that common mechanisms of signaling via TLRs link stimulation by multiple pathogens to atherosclerosis. However, how pathogen-specific stimulation of TLR4 contributes to atherosclerosis progression remains poorly understood. In this study, atherosclerosis-prone apolipoprotein-E null (ApoE(-/-)) and TLR4-deficient (ApoE(-/-)TLR4(-/-)) mice were orally infected with the periodontal pathogen Porphyromonas gingivalis. ApoE(-/-)TLR4(-/-) mice were markedly more susceptible to atherosclerosis after oral infection with P. gingivalis. Using live animal imaging, we demonstrate that enhanced lesion progression occurs progressively and was increasingly evident with advancing age. Immunohistochemical analysis of lesions from ApoE(-/-)TLR4(-/-) mice revealed an increased inflammatory cell infiltrate composed primarily of macrophages and IL-17 effector T cells (Th17), a subset linked with chronic inflammation. Furthermore, enhanced atherosclerosis in TLR4-deficient mice was associated with impaired development of Th1 immunity and regulatory T cell infiltration. In vitro studies suggest that the mechanism of TLR4-mediated protective immunity may be orchestrated by dendritic cell IL-12 and IL-10, which are prototypic Th1 and regulatory T cell polarizing cytokines. We demonstrate an atheroprotective role for TLR4 in response to infection with the oral pathogen P. gingivalis. Our results point to a role for pathogen-specific TLR signaling in chronic inflammation and atherosclerosis.

Causes of adverse pregnancy outcomes and the role of maternal periodontal status - a review of the literature

Preterm (PT) and Low birth weight (LBW) are considered to be the most relevant biological determinants of newborn infants survival, both in developed and in developing countries. Numerous risk factors for PT and LBW have been defined in the literature. Infections of the genitourinary tract infections along with various biological and genetic factors are considered to be the most common etiological factors for PT/LBW deliveries. However, evidence suggests that sub-clinical infection sites that are also distant from the genitor-urinary tract may be an important cause for PT/LBW deliveries. Maternal periodontal status has also been reported by many authors as a possible risk factor for PT and LBW, though not all of the actual data support such hypothesis. The aim of this paper is to review the evidence from various published literature on the association between the maternal periodontal status and adverse pregnancy outcomes. Although this review found a consistent association between periodontitis and PT/LBW, this finding should be treated with great caution until the sources of heterogeneity can be explained.

Oral health and oral health care practices among low-income pregnant women

INTRODUCTION

Access to dental care is a problem in California as in many parts of the United States. Many women, including half of those having dental problems, do not see a dentist during pregnancy. The objective of this study was to describe the oral health status and oral health practices of low-income pregnant women in San Diego, California, and to determine the needs for oral health care education in this population.

METHODS

This descriptive, retrospective, correlational study examined oral health and oral health care practices by age, ethnicity, and gravidity by using medical records from a convenience sample of 380 low-income pregnant women.

RESULTS

Most participants were primigravida, aged between 19 and 29 years, of Hispanic ethnicity, and insured by the state (Medi-Cal). All women received education on oral health. The majority (84%) were encouraged to get a dental examination. It had been more than 1 year since the last dental visit for most women (55%). Hispanic women were in need of dental care more than Filipina women or women of other ethnicities. A broken tooth was the primary reason for immediate dental referrals. Regularity of flossing and brushing teeth differed significantly (P= .015, P < .001) across ethnic groups, with Filipina women reporting better oral care practices.

DISCUSSION

The results provide information for the future planning of effective dental health promotion programs. Findings suggest that low-income pregnant women have some healthy oral health care practices but are in need of dental services and oral health education. An oral health history, oral health education, dental screening, and dental referral, if needed, should be a routine part of prenatal care and annual examinations.

Porphyromonas gingivalis accelerates inflammatory atherosclerosis in the innominate artery of ApoE deficient mice

OBJECTIVE

Studies in humans support a role for the oral pathogen Porphyromonas gingivalis in the development of inflammatory atherosclerosis. The goal of this study was to determine if P. gingivalis infection accelerates inflammation and atherosclerosis in the innominate artery of mice, an artery which has been reported to exhibit many features of human atherosclerotic disease, including plaque rupture.

METHODS AND RESULTS

Apolipoprotein E-deficient (ApoE-/-) mice were orally infected with P. gingivalis, and magnetic resonance imaging (MRI) was used to monitor the progression of atherosclerosis in live mice. P. gingivalis infected mice exhibited a statistically significant increase in atherosclerotic plaque in the innominate artery as compared to uninfected mice. Polarized light microscopy and immunohistochemistry revealed that the innominate arteries of infected mice had increased lipids, macrophages and T cells as compared to uninfected mice. Increases in plaque, total cholesterol esters and cholesterol monohydrate crystals, macrophages, and T cells were prevented by immunization with heat-killed P. gingivalis prior to pathogen exposure.

CONCLUSIONS

These are the first studies to demonstrate progression of inflammatory plaque accumulation in the innominate arteries by in vivo MRI analysis following pathogen exposure, and to document protection from plaque progression in the innominate artery via immunization.

Porphyromonas gingivalis accelerates inflammatory atherosclerosis in the innominate artery of ApoE deficient mice

OBJECTIVE

Studies in humans support a role for the oral pathogen Porphyromonas gingivalis in the development of inflammatory atherosclerosis. The goal of this study was to determine if P. gingivalis infection accelerates inflammation and atherosclerosis in the innominate artery of mice, an artery which has been reported to exhibit many features of human atherosclerotic disease, including plaque rupture.

METHODS AND RESULTS

Apolipoprotein E-deficient (ApoE-/-) mice were orally infected with P. gingivalis, and magnetic resonance imaging (MRI) was used to monitor the progression of atherosclerosis in live mice. P. gingivalis infected mice exhibited a statistically significant increase in atherosclerotic plaque in the innominate artery as compared to uninfected mice. Polarized light microscopy and immunohistochemistry revealed that the innominate arteries of infected mice had increased lipids, macrophages and T cells as compared to uninfected mice. Increases in plaque, total cholesterol esters and cholesterol monohydrate crystals, macrophages, and T cells were prevented by immunization with heat-killed P. gingivalis prior to pathogen exposure.

CONCLUSIONS

These are the first studies to demonstrate progression of inflammatory plaque accumulation in the innominate arteries by in vivo MRI analysis following pathogen exposure, and to document protection from plaque progression in the innominate artery via immunization.

Discovering Expectant Mothers' Beliefs about Oral Health: An Application of the Centering Pregnancy Smiles® Program

Research shows expectant mothers with oral infections may have an increased risk for delivering preterm, low birth weight babies. Difficulty accessing dental services, limited resources, and beliefs about dental care put expectant mothers from rural communities at a greater risk for oral health problems, which can have adverse health consequences for themselves and their unborn children. There is a need to better educate these women on proper oral health practices to decrease oral infections and increase the likelihood of delivering healthy babies. Using the Extended Parallel Process Model (EPPM) [1], this study examines the impact of a prenatal program, Centering Pregnancy Smiles® (CPS), on changing rural expectant mothers' attitudes and beliefs about maintaining good oral health during pregnancy. Results showed the CPS program had a primarily positive impact on changing expectant mothers' attitudes and beliefs regarding oral health. Implications for educational prenatal programs on oral health in rural areas are discussed.

Vaginal and oral microbes, host genotype and preterm birth

Preterm birth (PTB) is a leading cause of infant mortality and morbidity in the US and across the globe. Infection and associated inflammation are important initiators for PTB pathways; an estimated 40% of PTBs are attributed to amniochorionic-decidual or systemic inflammation. Historically, intrauterine infections have been implicated in PTB; recent evidence suggests that infections remote from the fetal site may also be causative. There is strong epidemiological evidence that bacterial vaginosis and periodontitis--two syndromes characterized by perturbations in the normal vaginal and oral bacterial microflora, respectively--are linked to infection-associated PTB. Oral and vaginal environments are similar in their bacterial microbiology; identical bacterial species have been independently isolated in periodontitis and bacterial vaginosis. Periodontitis and bacterial vaginosis also share many behavioral and sociodemographic risk factors suggesting a possible common pathophysiology. Genetic polymorphisms in host inflammatory responses to infection are shared between bacterial vaginosis, periodontitis and PTB, suggesting common mechanisms through which host genotype modify the effect of abnormal bacterial colonization on preterm birth. We review the state of knowledge regarding the risk of PTB attributable to perturbations in bacterial flora in oral and vaginal sites and the role of host genetics in modifying the risk of infection-related PTB. We posit that bacterial species that are common in perturbed vaginal and oral sites are associated with PTB through their interaction with the host immune system.

Anchoring and length regulation of Porphyromonas gingivalis Mfa1 fimbriae by the downstream gene product Mfa2

Porphyromonas gingivalis, a causative agent of periodontitis, has at least two types of thin, single-stranded fimbriae, termed FimA and Mfa1 (according to the names of major subunits), which can be discriminated by filament length and by the size of their major fimbrilin subunits. FimA fimbriae are long filaments that are easily detached from cells, whereas Mfa1 fimbriae are short filaments that are tightly bound to cells. However, a P. gingivalis ATCC 33277-derived mutant deficient in mfa2, a gene downstream of mfa1, produced long filaments (10 times longer than those of the parent), easily detached from the cell surface, similar to FimA fimbriae. Longer Mfa1 fimbriae contributed to stronger autoaggregation of bacterial cells. Complementation of the mutant with the wild-type mfa2 allele in trans restored the parental phenotype. Mfa2 is present in the outer membrane of P. gingivalis, but does not co-purify with the Mfa1 fimbriae. However, co-immunoprecipitation demonstrated that Mfa2 and Mfa1 are associated with each other in whole P. gingivalis cells. Furthermore, immunogold microscopy, including double labelling, confirmed that Mfa2 was located on the cell surface and likely associated with Mfa1 fimbriae. Mfa2 may therefore play a role as an anchor for the Mfa1 fimbriae and also as a regulator of Mfa1 filament length. Two additional downstream genes (pgn0289 and pgn0290) are co-transcribed with mfa1 (pgn0287) and mfa2 (pgn0288), and proteins derived from pgn0289, pgn0290 and pgn0291 appear to be accessory fimbrial components.

Diet-induced obesity in mice causes changes in immune responses and bone loss manifested by bacterial challenge

Obesity has been suggested to be associated with an increased susceptibility to bacterial infection. However, few studies have examined the effect of obesity on the immune response to bacterial infections. In the present study, we investigated the effect of obesity on innate immune responses to Porphyromonas gingivalis infection, an infection strongly associated with periodontitis. Mice with diet-induced obesity (DIO) and lean control C57BL/6 mice were infected orally or systemically with P. gingivalis, and periodontal pathology and systemic immune responses were examined postinfection. After oral infection with P. gingivalis, mice with DIO had a significantly higher level of alveolar bone loss than the lean controls. Oral microbial sampling disclosed higher levels of P. gingivalis in mice with DIO vs. lean mice during and after infection. Furthermore, animals with DIO exposed to oral infection or systemic inoculation of live P. gingivalis developed a blunted inflammatory response with reduced expression of TNF-alpha, IL-6, and serum amyloid A (SAA) at all time points compared with lean mice. Finally, peritoneal macrophages harvested from mice with DIO and exposed to P. gingivalis exhibited reduced levels of proinflammatory cytokines compared with lean mice and when exposed to P. gingivalis LPS treatment had a significantly reduced recruitment of NF-kappaB to both TNF-alpha and IL-10 promoters 30 min after exposure. These data indicate that obesity interferes with the ability of the immune system to appropriately respond to P. gingivalis infection and suggest that this immune dysregulation participates in the increased alveolar bone loss after bacterial infection observed in mice with DIO.

Evaluation of the incidence of preterm low birth weight in patients undergoing periodontal therapy

BACKGROUND

Preterm low birth weight was reported to be related to periodontal infections that might influence the fetus-placenta complex. The aim of this study was to provide periodontal treatment for pregnant women and to evaluate if this treatment can interfere with pregnancy duration and weight of the newborn.

METHODS

The sample consisted of 450 pregnant women who were under prenatal care at a polyclinic in Três Corações, Brazil. Women with risk factors, such as systemic alterations (ischemic cardiopathy, hypertension, tuberculosis, diabetes, cancer, anemia, seizure, psychopathology, urinary tract infection, sexually transmitted diseases, asthma, and human immunodeficiency virus), and/or users of alcohol, tobacco, and drugs were excluded from the study. Data related to age, socioeconomic level, race, marital status, number of previous pregnancies, and previous preterm delivery also were evaluated. Initially, the sample was divided into two groups: 122 healthy patients (group 1) and 328 patients with periodontal disease (group 2). In group 2, 266 patients underwent treatment and 62 patients dropped out. After mothers gave birth, pregnancy duration and the weight of all infants were analyzed and recorded.

RESULTS

There was no statistical difference between the healthy and treated groups. However, there was a difference in the non-treated group, with a 79% incidence of preterm low birth weight. Educational level, previous preterm birth, and periodontal disease were related significantly to preterm delivery (P <0.001).

CONCLUSION

Periodontal disease was related significantly to preterm low birth weight.

Periodontal infection and adverse pregnancy outcomes: a systematic review of epidemiological studies

The objective of this systematic review was to evaluate analytical studies on periodontal disease as a possible risk factor for adverse pregnancy outcomes. A literature search of the MEDLINE, SciELO, and LILACS bibliographic databases and CAPES thesis database was conducted up to December 2005, covering epidemiological studies of periodontal disease and adverse pregnancy outcomes. Of the 964 papers identified, 36 analytical studies met the inclusion criteria. Twenty-six epidemiological studies reported associations between periodontal disease and adverse pregnancy outcomes. There was a clear heterogeneity between studies concerning measurement of periodontal disease and selection of type of adverse pregnancy outcome. Therefore no meta-analysis was performed. Most studies did not control for confounders, thus raising serious doubts about their conclusions. The methodological limitations of most studies did not allow conclusions concerning the effects of periodontal disease on adverse pregnancy outcomes. Larger and methodologically rigorous analytical studies using reliable outcomes and exposure measures are recommended.

Innate immune signaling and Porphyromonas gingivalis-accelerated atherosclerosis

Periodontal diseases are a group of diseases that lead to erosion of the hard and soft tissues of the periodontium, which, in severe cases, can result in tooth loss. Anecdotal clinical observations have suggested that poor oral health may be associated with poor systemic health; however, only recently have appropriate epidemiological studies been initiated, with defined clinical endpoints of periodontal disease, to address the association of periodontal disease with increased risk for cardiovascular and cerebrovascular disease. Although conflicting reports exist, these epidemiological studies support this connection. Paralleling these epidemiological studies, emerging basic scientific studies also support that infection may represent a risk factor for atherosclerosis. With P. gingivalis as a model pathogen, in vitro studies support that this organism can activate host innate immune responses associated with atherosclerosis, and in vivo studies demonstrate that this organism can accelerate atheroma deposition in animal models. In this review, we focus primarily on the basic scientific studies performed to date which support that infection with bacteria, most notably P. gingivalis, accelerates atherosclerosis. Furthermore, we attempt to bring together these studies to provide an up-to-date framework of emerging theories into the mechanisms underlying periodontal disease and increased risk for atherosclerosis, as well as identify intervention strategies to reduce the incidence of periodontal disease in humans, in an attempt to decrease risk for systemic complications of periodontal disease such as atherosclerotic cardiovascular disease.

Perinatal infections, prematurity and brain injury

PURPOSE OF REVIEW

The association between perinatal infection and brain injury is widely accepted but a cause-and-effect relationship has not yet been proven. This article summarizes available evidence and current primary publications for debate.

RECENT FINDINGS

Work completed during the review period has reinforced current understanding of perinatal infection, prematurity and brain injury. In animal experiments: lipopolysaccharides have been further implicated in brain injury, not only as a cause of brain injury but also as mediators of preconditioning and protection. Recent studies suggest that cerebral injury following low-dose lipopolysaccharide administration may become compensated in adulthood. Other studies have emphasized the complexity of the response by showing that plasma cytokine levels may not reflect those in the central nervous system or inflammatory events in the brain.

SUMMARY

Perinatal infection and maternofetal inflammation is strongly associated with preterm birth. Inflammation probably represents an important mechanism for cerebral damage, and both overt lesions and maldevelopment can result. Epidemiological data and multiple animal models to link infection, inflammation and brain damage exist, but proof of causation is elusive.

Oral health in women with pregnancy and delivery complications

Oral health was retrospectively studied in 207 women (mean age 30 years) in the Helsinki Womens' Hospital with the hypothesis that women with pregnancy complications and/or delivery complications would present poorer dental status than women without complications. Computerized dental records of the City of Helsinki Health Department were used with decayed, missing, filled index (DMF) and community periodontal index (CPI) scoring systems and a summary dental health index (DHI) was constructed for statistics. In 72%, the delivery was uncomplicated, while 18% had Caesarean section. Of the women, 8% had gestational diabetes, 7.1% had gestational hypertension, and 1.8% had preeclampsia. Fifteen (6.6%) preterm babies were born; eight (3.5%) babies weighed <2.500 g, seven (3.2%) received a 1-min Apgar point <7 indicating less than satisfactory state of the newborn. DMF was 12.9+/-6.6 in women without complications compared to 15.3+/-6.7 in women with complications (n.s.). CPI values did not differ between the groups. The mean DHI values were 2.07 in women with normal pregnancy complications and no delivery complications, 2.23 in those with pregnancy complications, and 2.13 in those with delivery complications, respectively. In logistic regression analysis, no oral health parameters associated with any complications. Thus, this study failed to show an association between poor dental health and pregnancy or delivery complications.

Microarray analysis of quorum-sensing-regulated genes in Porphyromonas gingivalis

Quorum sensing is a phenomenon defined as gene regulation in response to cell density that regulates various functions in bacteria. The periodontopathogen Porphyromonas gingivalis possesses a luxS gene homologue that may encode a quorum-sensing system. In order to identify genes of P. gingivalis that are regulated by luxS, gene expression analysis was done using microarrays and RNA samples from the W83 wild-type strain and an isogenic luxS mutant, LY2001. The results indicated that 17 open reading frames (ORFs) in LY2001 are upregulated and two are downregulated. Real-time PCR was done to confirm the microarray results. Among the upregulated ORFs is a group of stress-related genes, including htrA, clpB, groEL, dnaK, and the F subunit of alkyl hydroperoxide reductase. This suggested that luxS is involved in stress gene regulation in P. gingivalis. Stress response experiments, including high-temperature survival, resistance to hydrogen peroxide (H2O2), and survival during exposure to low and high pH, were performed on the P. gingivalis wild-type and LY2001 strains. LY2001 had a significantly higher survival rate than did W83 when stressed at 50 degrees C. No difference was found at pH 5, but LY2001 had increased survival compared to W83 at pH 9. LY2001 also survived better than W83 when stressed with 0.35 mM H2O2. These results suggest that luxS might be involved in promoting survival of P. gingivalis in the host by regulating its response to host-induced stresses such as temperature, H2O2, and pH.

Clinical risk factors associated with incidence and progression of periodontal conditions in pregnant women

OBJECTIVES

Few large studies have investigated the progression of periodontal conditions during pregnancy in a comprehensive manner. This study aimed to identify clinical factors that were predictive of incidence/progression of periodontal measures in pregnant women adjusting for relevant predictors.

MATERIAL AND METHODS

Periodontal examinations were conducted on 891 pregnant women prior to 26 weeks gestational age and within 48 h after delivery. Gingivitis/periodontitis incidence/progression (GPIP) was defined as four plus sites with 2+ mm increase in probing depth (PD) that resulted in PD of at least 4 mm at delivery. Multivariable models including relevant clinical variables and significant covariates were developed.

RESULTS

While several clinical measures were significantly associated with the outcome, having >/=10% of sites with bleeding on probing (BOP) and four plus sites with PD >/=4 mm (PD4) were the best two predictors of GPIP (odds ratio (OR)=2.8, 95% confidence interval (CI)=1.8-4.2; OR=2.0, 95% CI=1.4-2.9, respectively), adjusting for maternal race, age, enrollment weight, smoking during pregnancy, marital status, food stamp eligibility, and private health insurance. Multivariable models assessed the impact of BOP on the PD4-GPIP relationship. PD4 was significant in the presence of BOP (low BOP OR=1.3, 95% CI=0.5-3.3; high BOP OR=3.0, 95% CI=2.2-4.3).

CONCLUSIONS

Enrollment BOP and PD4 were significant predictors of PD in pregnant women, however; PD4 is only a predictor with BOP.

Periodontal disease and upper genital tract inflammation in early spontaneous preterm birth

OBJECTIVE

To estimate the relationship between maternal periodontal disease and both early spontaneous preterm birth and selected markers of upper genital tract inflammation.

METHODS

In this case-control study, periodontal assessment was performed in 59 women who experienced an early spontaneous preterm birth at less than 32 weeks of gestation, in a control population of 36 women who experienced an early indicated preterm birth at less than 32 weeks of gestation, and in 44 women with an uncomplicated birth at term (>or = 37 weeks). Periodontal disease was defined by the degree of attachment loss. Cultures of the placenta and umbilical cord blood, cord interleukin-6 levels, and histopathologic examination of the placenta were performed for all women.

RESULTS

Severe periodontal disease was more common in the spontaneous preterm birth group (49%) than in the indicated preterm (25%, P =.02) and term control groups (30%, P =.045). Multivariable analyses, controlling for possible confounders, supported the association between severe periodontal disease and spontaneous preterm birth (odds ratio 3.4, 95% confidence interval 1.5-7.7). Neither histologic chorioamnionitis, a positive placental culture, nor an elevated cord plasma interleukin-6 level was significantly associated with periodontal disease (80% power to detect a 50% difference in rate of histological chorioamnionitis, alpha = 0.05).

CONCLUSION

Women with early spontaneous preterm birth were more likely to have severe periodontal disease than women with indicated preterm birth or term birth. Periodontal disease was not associated with selected markers of upper genital tract inflammation.

LEVEL OF EVIDENCE

II-2