ABSTRACT
INTRODUCTION: The functional interplay between cementum of the root and alveolar bone of the socket is tuned by a uniquely positioned 70-80 µm wide fibrous and lubricious ligament in a dentoalveolar joint (DAJ). In this study, structural and biomechanical properties of the DAJ, periodontal ligament space (PDL-space also known as the joint space), alveolar bone of the socket, and cementum of the tooth root that govern the biomechanics of a lipopolysaccharide (LPS)-affected DAJ were mapped both in space and time. METHODS: The hemi-maxillae from 20 rats (4 control at 6 weeks of age, 4 control and 4 LPS-affected at 12 weeks of age, 4 control and 4 LPS-affected at 16 weeks of age) were investigated using a hybrid technique; micro-X-ray computed tomography (5 µm resolution) in combination with biomechanical testing in situ. Temporal variations in bone and cementum volume fractions were evaluated. Trends in mineral apposition rates (MAR) in additional six Sprague Dawley rats (3 controls, 3 LPS-affected) were revealed by transforming spatial fluorochrome signals to functional growth rates (linearity factor - RW) of bone, dentin, and cementum using a fast Fourier transform on fluorochrome signals from 100-µm hemi-maxillae sections. RESULTS: An overall change in LPS-affected DAJ biomechanics (a 2.5-4.5X increase in tooth displacement and 2X tooth rotation at 6 weeks, no increase in displacement and a 7X increase in rotation at 12 weeks; 27% increase in bone effective strain at 6 weeks and 11% at 12 weeks relative to control) was associated with structural changes in the coronal regions of the DAJ (15% increase in PDL-space from 0 to 6 weeks but only 5% from 6 to 12 weeks compared to control). A significant increase (p < 0.05) in PDL-space between ligated and age-matched control was observed. The bone fraction of ligated at 12 weeks was significantly lower than its age-matched control, and no significant differences (p > 0.05) between groups were observed at 6 weeks. Cementum in the apical regions grew faster but nonlinearly (11% and 20% increase in cementum fraction (CF) at 6 and 12 weeks) compared to control. Alveolar bone revealed site-specific nonlinear growth with an overall increase in MAR (108.5 µm/week to 126.7 µm/week after LPS treatment) compared to dentin (28.3 µm/week in control vs. 26.1 µm/week in LPS-affected) and cementum (126.5 µm/week in control vs. 119.9 µm/week in LPS-affected). A significant increase in CF (p < 0.05) in ligated specimens was observed at 6 weeks of age. CONCLUSIONS: Anatomy-specific responses of cementum and bone to the mechano-chemo stimuli, and their collective temporal contribution to observed changes in PDL-space were perpetuated by altered tooth movement. Data highlight the "resilience" of DAJ function through the predominance of nonlinear growth response of cementum, changes in PDL-space, and bone architecture. Despite the significant differences in bone and cementum architectures, data provided insights into the reactionary effects of cementum as a built-in compensatory mechanism to reestablish functional competence of the DAJ. The spatial shifts in architectures of alveolar bone and cementum, and consequently ligament space, highlight adaptations farther away from the site of insult, which also is another novel insight from this study. These adaptations when correlated within the context of joint function (biomechanics) illustrate that they are indeed necessary to sustain DAJ function albeit being pathological.
Subject(s)
Dental Cementum , Lipopolysaccharides , Animals , Maxilla , Periodontal Ligament/diagnostic imaging , Rats , Rats, Sprague-DawleyABSTRACT
Loss of cognitive function in the aging population, particular those with Alzheimer disease, presents unique challenges to health practitioners. For the dental practitioner these include management of periodontal diseases, caries, and other dental conditions in this special population. It is well established in the cognitively impaired patient that a lack of adherence to dental hygiene routines and professional care leads to increases in the prevalence and severity of these dental conditions, leading to increased loss of teeth. More recent evidence has indicated a possible role of the microbiota of dental plaque associated with periodontal diseases in the development and progression of Alzheimer disease, thereby supporting a two-way interaction of these two diseases. New therapies are needed to address the potential upstream events that may precede overt signs of Alzheimer disease. One of these approaches would be to target these various bacterial, viral, and other microbial pathogens associated with periodontal disease that can translocate into the bloodstream and then to distal sites, such as the brain. Such microbial translocation would lead to local inflammation and buildup of the hallmark signs of Alzheimer disease, including amyloid beta deposits, tau fragmentation and tangles, breakdown of host protective molecules, such as the apolipoproteins, and neuron toxicity. In this review, evidence for the biological basis of the role of the periodontal disease microflora on the initiation and progression of Alzheimer disease will be presented with a focus on the potential role of the keystone pathogen Porphyromonas gingivalis with its family of gingipain enzymes. The various mechanisms for which P. gingivalis gingipains may contribute to the initiation and progression of Alzheimer disease are presented. Small-molecule inhibitors of these gingipains and their effects on reducing biological markers of Alzheimer disease may have beneficial effects for the initiation and progression of loss of cognitive function in Alzheimer disease. In addition to these targeted therapies for specific periodontal pathogens, considerations for the dental practitioner in applying more general approaches to reducing the periodontal plaque microflora in the management of the cognitively impaired patient are discussed for this special population.
Subject(s)
Alzheimer Disease , Aged , Alzheimer Disease/therapy , Amyloid beta-Peptides , Dentists , Humans , Porphyromonas gingivalis , Professional RoleABSTRACT
The United States continues to be an incubator for new concepts and approaches to the diagnosis, treatment, and prevention of periodontal diseases. This volume of Periodontology 2000 presents some of these newer areas of research and paradigms that have emerged in the United States from both long-established and new investigators. These areas include: (1) more comprehensive approaches to assessing the total periodontal microbiome, including bacteria, viruses, and fungi, and their interactions with both the local and systemic inflammatory and immune responses, as well as with other oral and systemic conditions and diseases; (2) new developments for a more comprehensive characterization of the patient genome, transcriptome, and proteome profiles and the role of these profiles in periodontal disease pathogenesis; (3) new developments in nonsurgical approaches to periodontal diseases, including broad-based lines of attack using natural antimicrobials and host-modulation therapies and more focused approaches that target specific interactions in the host response; and (4) new big data analysis, machine learning, and imaging approaches, both for understanding the pathogenesis of periodontal diseases and for developing improved risk-assessment tools and better treatment outcomes.
Subject(s)
Periodontal Diseases , Periodontics , Dental Care , Humans , Treatment Outcome , United StatesABSTRACT
With the advent of combined antiretroviral therapies, the face of HIV infection has changed dramatically from a disease with almost certain mortality from serious comorbidities, to a manageable chronic condition with an extended lifespan. In this paper we present the more recent investigations into the epidemiology, microbiology, and pathogenesis of periodontal diseases in patients with HIV, and the effects of combined antiretroviral therapies on the incidence and progression of these diseases both in adults and perinatally infected children. In addition, comparisons and potential interactions between the HIV-associated microbiome, host responses, and pathogenesis in the oral cavity with the gastrointestinal tract and other areas of the body are presented. Also, the effects of HIV and combined antiretroviral therapies on comorbidities such as hyposalivation, dementia, and osteoporosis on periodontal disease progression are discussed.
Subject(s)
HIV Infections , Periodontal Diseases , Adult , Child , Chronic Disease , Disease Progression , HumansABSTRACT
In humans, the composition of microbial communities differs among body sites and between habitats within a single site. Patterns of variation in the distribution of organisms across time and space are referred to as "biogeography." The human oral cavity is a critical observatory for exploring microbial biogeography because it is spatially structured, easily accessible, and its microbiota has been linked to the promotion of both health and disease. The biogeographic features of microbial communities residing in spatially distinct, but ecologically similar, environments on the human body, including the subgingival crevice, have not yet been adequately explored. The purpose of this paper is twofold. First, we seek to provide the dental community with a primer on biogeographic theory, highlighting its relevance to the study of the human oral cavity. We summarize what is known about the biogeographic variation of dental caries and periodontitis and postulate that disease occurrence reflects spatial patterning in the composition and structure of oral microbial communities. Second, we present a number of methods that investigators can use to test specific hypotheses using biogeographic theory. To anchor our discussion, we apply each method to a case study and examine the spatial variation of the human subgingival microbiota in 2 individuals. Our case study suggests that the composition of subgingival communities may conform to an anterior-to-posterior gradient within the oral cavity. The gradient appears to be structured by both deterministic and nondeterministic processes, although additional work is needed to confirm these findings. A better understanding of biogeographic patterns and processes will lead to improved efficacy of dental interventions targeting the oral microbiota.
Subject(s)
Dental Caries , Microbiota , Periodontal Diseases , Periodontitis , Humans , MouthABSTRACT
AIM: To examine oral biomarkers that have been associated with periodontal disease progression in HIV-infected adults in perinatally HIV-infected and HIV-exposed but uninfected youth. MATERIAL AND METHODS: This was a cross-sectional, multicentre substudy of youth participating in the Oral Health Pediatric HIV/AIDS Cohort study. Gingival crevicular fluid repository samples from participants with and without periodontal disease (using Gingival Index [GI] and Bleeding on Probing [BOP] parameters on dental examination) were tested for concentration levels of inflammatory biomarkers. Associations were assessed using Wilcoxon test and Spearman correlation. RESULTS: For perinatal HIV youth (n = 129), the markers consistently elevated (p < .05) in sites with GI ≥2 and in sites with BOP were interleukin-1ß, 6 and 13, macrophage inflammatory protein-1α and metalloproteinase-9. Serum tumour necrosis factor-α and soluble CD14 were positively correlated with a summary count of elevated cytokines. No associations were seen among HIV-uninfected subjects (n = 71). CONCLUSIONS: The association of oral biomarkers of inflammation with clinical indicators of periodontal inflammation and systemic immune activation suggests that perinatal HIV-infected youth may be at higher risk for developing significant periodontal disease, associated with tooth loss and HIV progression. More frequent dental care of this group is needed to prevent potential periodontal progression.
Subject(s)
Gingival Crevicular Fluid , HIV Infections , Adolescent , Adult , Biomarkers , Child , Cohort Studies , Cross-Sectional Studies , Female , Humans , Inflammation , PregnancyABSTRACT
The use of various forms of tobacco is one of the most important preventable risk factors for the incidence and progression of periodontal disease. Tobacco use negatively affects treatment outcomes for both periodontal diseases and conditions, and for dental implants. Tobacco-cessation programs can mitigate these adverse dental treatment outcomes and may be the most effective component of a personalized periodontal treatment approach. In addition, heavy alcohol consumption may exacerbate the adverse effects of tobacco use. In this review, the microbiology, host/inflammatory responses and genetic characteristics of the tobacco-using patient are presented as a framework to aid the practitioner in developing personalized treatment strategies for these patients. These personalized approaches can be used for patients who use a variety of tobacco products, including cigarettes, cigars, pipes, smokeless tobacco products, e-cigarettes and other tobacco forms, as well as patients who consume large amounts of alcohol. In addition, principles for developing personalized tobacco-cessation programs, using both traditional and newer motivational and pharmacological approaches, are presented.
Subject(s)
Alcohol Drinking , Nicotiana/adverse effects , Periodontal Diseases/psychology , Periodontal Diseases/therapy , Tobacco Products/adverse effects , Alcohol Drinking/adverse effects , Alcohol Drinking/genetics , Alcohol Drinking/psychology , Alcohol Drinking/therapy , Dental Care , Electronic Nicotine Delivery Systems , Humans , Periodontal Diseases/genetics , Periodontal Diseases/microbiology , Risk Factors , Smoking/adverse effects , Smoking/psychology , Smoking/therapy , Smoking Cessation/methods , Smoking Cessation/psychology , Tobacco Use Cessation/methods , Tobacco Use Cessation/psychology , Tobacco, Smokeless/adverse effectsABSTRACT
AIMS: To compare the prevalence and severity of periodontal diseases between 180 perinatally HIV-infected (PHIV) and 118 perinatally HIV-exposed and uninfected (PHEU) youth in a cross-sectional study conducted at 11 clinical sites in the United States and Puerto Rico from the Adolescent Master Protocol study of the Pediatric HIV/AIDS cohort study (PHACS) network. METHODS: Several analyses were conducted, employing the current CDC/AAP classification for periodontitis and incorporating a definition of gingivitis based on a bleeding on probing (BOP) threshold, and analyses based on more detailed whole-mouth, intra-oral regionally, site-based and tooth-based criteria of BOP, plaque levels, pockets depths and clinical attachment levels. RESULTS: After adjusting for plaque control habits and behavioural and sociodemographic factors, there were no significant differences in periodontal diseases between the PHIV and PHEU youth using any of these criteria. For PHIV youth, there was no significant association between parameters of periodontal disease and current HIV status. CONCLUSIONS: Although no significant differences in periodontal parameters were noted between the PHIV and PHEU youth, the influence of antiretroviral therapy merits further exploration in this cohort in a longitudinal study.
Subject(s)
HIV Infections/complications , Periodontal Diseases/complications , Periodontal Diseases/epidemiology , Adolescent , Child , Female , HIV Infections/transmission , Humans , Infectious Disease Transmission, Vertical , Male , Prevalence , Prospective Studies , Risk Factors , Severity of Illness Index , Young AdultABSTRACT
In contrast to high rates of oral human papillomavirus (HPV) found in human immunodeficiency virus (HIV)-infected adults, only 2% of 209 perinatally HIV-infected youth had oral HPV. This rate was similar in HIV-exposed but uninfected youth. No association was found with sexual activity; however, low CD4 counts were associated with oral HPV.
Subject(s)
Acquired Immunodeficiency Syndrome/complications , HIV Infections/complications , Mouth Diseases/complications , Papillomaviridae/isolation & purification , Papillomavirus Infections/complications , Acquired Immunodeficiency Syndrome/epidemiology , Acquired Immunodeficiency Syndrome/virology , Adolescent , CD4 Lymphocyte Count , California/epidemiology , Cohort Studies , Coinfection , Cross-Sectional Studies , Female , Genotype , HIV Infections/virology , Humans , Male , Mouth Diseases/diagnosis , Mouth Diseases/epidemiology , Mouth Diseases/virology , Papillomaviridae/genetics , Papillomavirus Infections/diagnosis , Papillomavirus Infections/epidemiology , Papillomavirus Infections/virology , Viral LoadABSTRACT
There remains a high prevalence of mild-to-moderate forms of periodontal diseases in both developed and developing countries. Although many periodontal specialty practices currently place strong emphasis on implant surgery, periodontal plastic surgery and esthetics, general dentists and hygienists have often assumed more responsibility than periodontal specialty practices for the diagnosis, treatment, assessment and maintenance, and possible referral, of their patients. To address these current trends and challenges, this volume of Periodontology 2000 presents a series of topics on the basic biological principles of periodontal disease, as well as on approaches to diagnosis, treatment planning and treatment, in what is called 'conservative' or 'noninvasive' periodontal therapy. These topics include risk assessment of the periodontal condition; reduction, elimination and/or control of etiologies and risk factors, including mechanical, antimicrobial and host-modulation approaches; considerations for evaluation of clinical outcomes based on treatment approaches; and selected topics in laser therapy, halitosis and gingival recession.
Subject(s)
Periodontal Diseases/therapy , Periodontics/methods , Dental Hygienists , Dentists , General Practitioners , Humans , Periodontal Diseases/diagnosis , Treatment OutcomeABSTRACT
Although the prevalence of tobacco use has declined in some parts of the world, tobacco use remains a persistent and, in some cases, growing problem that will continue to be a fundamental challenge facing dental practitioners in the decades ahead. Dental practitioners have a unique opportunity and professional obligation to be a positive influence in reducing the economic and social burden inflicted by tobacco use on dental and general health. In this article, the current noninvasive, evidence-based approaches are presented for dental practitioners to help patients avoid initiating tobacco use, to encourage and assist patients in ceasing tobacco use and to address tobacco-induced damage to periodontal supporting tissues.
Subject(s)
Periodontal Diseases/etiology , Periodontal Diseases/therapy , Tobacco Products/adverse effects , Tobacco Use Cessation/methods , Dental Hygienists , Dentists , Disease Management , Humans , Periodontal Diseases/prevention & controlABSTRACT
Since the early 1990's, the death rate from AIDS among adults has declined in most developed countries, largely because of newer antiretroviral therapies and improved access to these therapies. In addition, from 2006 to 2011, the total number of new cases of HIV infection worldwide has declined somewhat and has remained relatively constant. Nevertheless, because of the large numbers of existing and new cases of HIV infection, the dental practitioner and other healthcare practitioners will still be required to treat oral and periodontal conditions unique to HIV/AIDS as well as conventional periodontal diseases in HIV-infected adults and children. The oral and periodontal conditions most closely associated with HIV infection include oral candidiasis, oral hairy leukoplakia, Kaposi's sarcoma, salivary gland diseases, oral warts, other oral viral infections, linear gingival erythema and necrotizing gingival and periodontal diseases. While the incidence and prevalence of these oral lesions and conditions appear to be declining, in part because of antiretroviral therapy, dental and healthcare practitioners will need to continue to diagnose and treat the more conventional periodontal diseases in these HIV-infected populations. Finding low-cost and easily accessible and acceptable diagnostic and treatment approaches for both the microbiological and the inflammatory aspects of periodontal diseases in these populations are of particular importance, as the systemic spread of the local microbiota and inflammatory products of periodontal diseases may have adverse effects on both the progression of HIV infection and the effectiveness of antiretroviral therapy approaches. Developing and assessing low-cost and accessible diagnostic and treatment approaches to periodontal diseases, particularly in developing countries, will require an internationally coordinated effort to design and conduct standardized clinical trials.
Subject(s)
AIDS-Related Opportunistic Infections/complications , Acquired Immunodeficiency Syndrome/complications , HIV Infections/complications , Periodontal Diseases/complications , AIDS-Related Opportunistic Infections/therapy , Acquired Immunodeficiency Syndrome/drug therapy , Anti-Retroviral Agents/therapeutic use , Developed Countries , Developing Countries , Disease Progression , HIV Infections/drug therapy , Host-Pathogen Interactions , Humans , Periodontal Diseases/therapyABSTRACT
Epidemiological studies have identified an association between periodontitis and Alzheimer disease (AD); however, the nature of this association has been unclear. Recent work suggests that brain colonization by the periodontal pathogen Porphyromonas gingivalis may link these two inflammatory and degenerative conditions. Evidence of P. gingivalis infiltration has been detected in autopsy specimens from the brains of people with AD and in cerebrospinal fluid of individuals diagnosed with AD. Gingipains, a class of P. gingivalis proteases, are found in association with neurons, tau tangles, and beta-amyloid in specimens from the brains of individuals with AD. The brains of mice orally infected with P. gingivalis show evidence of P. gingivalis infiltration, along with various neuropathological hallmarks of AD. Oral administration of gingipain inhibitors to mice with established brain infections decreases the abundance of P. gingivalis DNA in brain and mitigates the neurotoxic effects of P. gingivalis infection. Thus, gingipain inhibition could provide a potential approach to the treatment of both periodontitis and AD.
Subject(s)
Alzheimer Disease , Bacteroidaceae Infections , Periodontitis , Adhesins, Bacterial , Alzheimer Disease/drug therapy , Animals , Bacteroidaceae Infections/drug therapy , Cysteine Endopeptidases , Humans , Mice , Porphyromonas gingivalisABSTRACT
COR388, a small-molecule lysine-gingipain inhibitor, is currently being investigated in a Phase 2/3 clinical trial for Alzheimer's disease (AD) with exploratory endpoints in periodontal disease. Gingipains are produced by two species of bacteria, Porphyromonas gingivalis and Porphyromonas gulae, typically associated with periodontal disease and systemic infections in humans and dogs, respectively. P. gulae infection in dogs is associated with periodontal disease, which provides a physiologically relevant model to investigate the pharmacology of COR388. In the current study, aged dogs with a natural oral infection of P. gulae and periodontal disease were treated with COR388 by oral administration for up to 90 days to assess lysine-gingipain target engagement and reduction of bacterial load and downstream pathology. In a 28-day dose-response study, COR388 inhibited the lysine-gingipain target and reduced P. gulae load in saliva, buccal cells, and gingival crevicular fluid. The lowest effective dose was continued for 90 days and was efficacious in continuous reduction of bacterial load and downstream periodontal disease pathology. In a separate histology study, dog brain tissue showed evidence of P. gulae DNA and neuronal lysine-gingipain, demonstrating that P. gulae infection is systemic and spreads beyond its oral reservoir, similar to recent observations of P. gingivalis in humans. Together, the pharmacokinetics and pharmacodynamics of COR388 lysine-gingipain inhibition, along with reduction of bacterial load and periodontal disease in naturally occurring P. gulae infection in the dog, support the use of COR388 in targeting lysine-gingipain and eliminating P. gingivalis infection in humans.
Subject(s)
Bacteroidaceae Infections/drug therapy , Dog Diseases/microbiology , Gingipain Cysteine Endopeptidases/antagonists & inhibitors , Organic Chemicals/administration & dosage , Periodontal Diseases/drug therapy , Porphyromonas/enzymology , Small Molecule Libraries/administration & dosage , Administration, Oral , Aging/blood , Animals , Bacterial Load , Bacterial Proteins/antagonists & inhibitors , Bacteroidaceae Infections/veterinary , Brain/drug effects , Brain/microbiology , Dog Diseases/drug therapy , Dogs , Gene Expression Regulation, Bacterial/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Gingival Crevicular Fluid/drug effects , Gingival Crevicular Fluid/microbiology , Organic Chemicals/chemistry , Organic Chemicals/pharmacology , Periodontal Diseases/veterinary , Porphyromonas/drug effects , Porphyromonas/pathogenicity , Saliva/drug effects , Saliva/microbiology , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacologyABSTRACT
Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, was identified in the brain of Alzheimer's disease patients. Toxic proteases from the bacterium called gingipains were also identified in the brain of Alzheimer's patients, and levels correlated with tau and ubiquitin pathology. Oral P. gingivalis infection in mice resulted in brain colonization and increased production of Aß1-42, a component of amyloid plaques. Further, gingipains were neurotoxic in vivo and in vitro, exerting detrimental effects on tau, a protein needed for normal neuronal function. To block this neurotoxicity, we designed and synthesized small-molecule inhibitors targeting gingipains. Gingipain inhibition reduced the bacterial load of an established P. gingivalis brain infection, blocked Aß1-42 production, reduced neuroinflammation, and rescued neurons in the hippocampus. These data suggest that gingipain inhibitors could be valuable for treating P. gingivalis brain colonization and neurodegeneration in Alzheimer's disease.
Subject(s)
Alzheimer Disease/drug therapy , Alzheimer Disease/microbiology , Bacteroidaceae Infections/drug therapy , Brain/microbiology , Brain/pathology , Neuroprotective Agents/therapeutic use , Porphyromonas gingivalis/enzymology , Small Molecule Libraries/therapeutic use , Aged , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Animals , Bacteroidaceae Infections/microbiology , Cell Line, Tumor , Disease Models, Animal , Female , Gingipain Cysteine Endopeptidases/antagonists & inhibitors , Gingipain Cysteine Endopeptidases/metabolism , Gingipain Cysteine Endopeptidases/pharmacology , Humans , Male , Mice , Mice, Inbred BALB C , Middle Aged , Neuroprotective Agents/pharmacology , Peptide Fragments/metabolism , Pilot Projects , Porphyromonas gingivalis/drug effects , Porphyromonas gingivalis/genetics , Prospective Studies , Saliva/microbiology , Small Molecule Libraries/pharmacology , tau Proteins/metabolismABSTRACT
The challenges, problems, and solutions for developing a more streamlined and integrated curriculum at the University of California, San Francisco, School of Dentistry (UCSF) centered on thematic streams are presented. The central feature of the approach was that the curriculum reform efforts were initiated, developed, and implemented for the 2004-05 academic year primarily as a grassroots faculty effort with support by the administration. In addition, the issues in obtaining the consensus support of the faculty, students, and administration in order to proceed to implementation are discussed. Under the direction of a newly created position of assistant dean of curricular affairs and a faculty curriculum oversight group initiated in 2002, curriculum hours were adjusted to thirty-two hours per week. Departments conformed to this schedule, resulting in reductions in all areas of the curriculum, except clinical instruction, in order to provide time for independent study and electives. A new two-week introduction to the curriculum and an online course support system were also instituted. The new courses were generally well reviewed by students and faculty. Formal course evaluations and focus groups provided specific indications of needed adjustments. National Board scores were monitored and found to be unchanged from past experience. Curriculum change at UCSF required many changes in faculty behavior, including interdepartmental collaboration and efforts to improve teaching. Although many issues were anticipated and addressed in this multiyear reform process, careful faculty and administrative oversight continues to be required to maintain this structure. Continuing challenges include better integration of course materials and incorporating more learner-centered teaching strategies into the curriculum.
Subject(s)
Curriculum , Education, Dental/methods , Organizational Innovation , Administrative Personnel , Attitude of Health Personnel , Educational Measurement/methods , Humans , Models, Educational , Program Development , Program Evaluation , San Francisco , Schools, Dental , Students, Dental/psychology , Time FactorsABSTRACT
OBJECTIVES: This study explores the association between combination antiretroviral therapy (cART) and oral health outcomes (dental and periodontal) among perinatally HIV-infected (PHIV) youth. METHODS: We conducted a cross-sectional study of oral health among PHIV youth participating in the Oral Health substudy of the Pediatric HIV/AIDS Cohort Study (PHACS). Dentists at research sites were trained/calibrated on how to perform a standardized oral mucosal, dental and periodontal examination. They assessed the decayed-missing-filled-surfaces and teeth index (DMFS/T). The number of decayed surfaces and teeth and the number of teeth with gingival bleeding on probing for each participant were derived from the examination. Data for analysis included lifetime measurements of CD4 cell count and viral load, sociodemographic information and current/past history of ART. RESULTS: Among 209 PHIV youth, 95% were on ART at the time of enrolment. Among 143 PHIV youth on the same cART for at least 1 year, we found that the mean decayed teeth score of those receiving cART containing an integrase inhibitor was 86% higher than that of those on cART without an integrase inhibitor after adjusting for age, lifetime proportion of unsuppressed viral load and CD4 cell count nadir. Initiating protease inhibitors before age 6 years was associated with a significantly lower DMFT score than participants who initiated at age 6 years and older. CONCLUSION: Our study revealed that PHIV youth who received cART containing an integrase inhibitor had a significantly higher number of untreated active caries than those on cART without an integrase inhibitor. This may warrant closer dental surveillance of those receiving an integrase inhibitor.
Subject(s)
Anti-Retroviral Agents/administration & dosage , Antiretroviral Therapy, Highly Active/methods , HIV Infections/complications , HIV Infections/drug therapy , Periodontal Diseases/epidemiology , Stomatognathic Diseases/epidemiology , Adolescent , CD4 Lymphocyte Count , Cross-Sectional Studies , Female , Humans , Male , Periodontal Diseases/pathology , Stomatognathic Diseases/pathology , Viral Load , Young AdultABSTRACT
Spatial and temporal patterns in microbial communities provide insights into the forces that shape them, their functions and roles in health and disease. Here, we used spatial and ecological statistics to analyze the role that saliva plays in structuring bacterial communities of the human mouth using >9000 dental and mucosal samples. We show that regardless of tissue type (teeth, alveolar mucosa, keratinized gingiva, or buccal mucosa), surface-associated bacterial communities vary along an ecological gradient from the front to the back of the mouth, and that on exposed tooth surfaces, the gradient is pronounced on lingual compared to buccal surfaces. Furthermore, our data suggest that this gradient is attenuated in individuals with low salivary flow due to Sjögren's syndrome. Taken together, our findings imply that salivary flow influences the spatial organization of microbial communities and that biogeographical patterns may be useful for understanding host physiological processes and for predicting disease.
Subject(s)
Bacteria/growth & development , Mouth/microbiology , Saliva/microbiology , Salivation , Adult , Aged , Bacteria/classification , Bacteria/genetics , Biodiversity , Female , Genetic Variation , Humans , Male , Middle Aged , Mouth Mucosa/microbiology , RNA, Ribosomal, 16S/genetics , Saliva/metabolism , Sjogren's Syndrome/complications , Sjogren's Syndrome/microbiology , Tongue/microbiology , Tooth/microbiology , Xerostomia/etiology , Xerostomia/microbiology , Young AdultABSTRACT
BACKGROUND: Microbially mediated oral diseases can signal underlying HIV/AIDS progression in HIV-infected adults. The role of the oral microbiota in HIV-infected youth is not known. The Adolescent Master Protocol of the Pediatric HIV/AIDS Cohort Study is a longitudinal study of perinatally HIV-infected (PHIV) and HIV-exposed, uninfected (PHEU) youth. We compared oral microbiome levels and associations with caries or periodontitis in 154 PHIV and 100 PHEU youth. RESULTS: Species richness and alpha diversity differed little between PHIV and PHEU youth. Group differences in average counts met the significance threshold for six taxa; two Corynebacterium species were lower in PHIV and met thresholds for noteworthiness. Several known periodontitis-associated organisms (Prevotella nigrescens, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, and Filifactor alocis) exhibited expected associations with periodontitis in PHEU youth, associations not observed in PHIV youth. In both groups, odds of caries increased with counts of taxa in four genera, Streptococcus, Scardovia, Bifidobacterium, and Lactobacillus. CONCLUSIONS: The microbiomes of PHIV and PHEU youth were similar, although PHIV youth seemed to have fewer "health"-associated taxa such as Corynebacterium species. These results are consistent with the hypothesis that HIV infection, or its treatment, may contribute to oral dysbiosis.