Subgingival microbiota in adult Down syndrome periodontitis

Efficacy of periodontal treatment modalities in Down syndrome patients: a systematic review and meta-analysis

OBJECTIVE

The systematic review aimed to review the existing evidence, to identify and appraise the effectiveness of periodontal prevention and treatment modalities in individuals diagnosed with Down syndrome (DS) and to determine the estimates of the effects of implemented periodontal prevention and treatment strategies compared to chromosomally normal (CN) individuals.

METHODOLOGY

The systematic review was conducted and reported in conformity with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. The study protocol was registered in the Open Science Framework. Electronic and manual searches, in accordance with PICO framework and delineated inclusion/exclusion criteria, were conducted in multiple databases.

RESULTS

The initial search identified 11,704 studies. After removing duplicates, 9,048 remained. Title and abstract screening narrowed these to 281 for full-text review. Ultimately, 16 studies met the inclusion criteria, with 4 eligible for quantitative data synthesis. Results of the meta-analysis indicated that professional tooth cleaning in combination with oral hygiene reinforcement was less effective in the reduction of PPD in patients with DS compared to those without DS (Mean difference (MD): 0.23; 95% Confidence Interval (CI): 0.14 to 0.32; p < 0.001).

DISCUSSION

These findings suggest that conventional periodontal treatment is less effective in managing periodontitis in patients with DS. Thus, tailored periodontal care strategies that address the specific needs of individuals with DS should be implemented to improve treatment outcomes for this population The presence of moderate to high risk of bias in the included studies underscores the need for rigorously designed research that minimizes bias through effective blinding, randomization, control of confounding factors, and inclusion of diverse treatment outcomes to further investigate these associations.

CONCLUSION

Based on the best available evidence, professional tooth cleaning combined with oral hygiene instructions appears to be less effective in reducing pocket depths in individuals with DS compared to those without DS. https://doi.org/10.17605/OSF.IO/UXTCG.

Oral Prevalence of Selenomonas noxia Differs among Orthodontic Patients Compared to Non-Orthodontic Controls: A Retrospective Biorepository Analysis

The oral microbial flora may be significantly altered by orthodontic therapy and the use of fixed orthodontic brackets. Most orthodontic research has focused on cariogenic pathogens, while some evidence has demonstrated an increase in many known periodontal pathogens. However, little is known about the prevalence of the Gram-negative periodontal pathogen Selenomonas noxia (SN) among these patients. Using an existing saliva biorepository, n = 208 samples from adult and pediatric orthodontic and non-orthodontic patients were identified and screened for the presence of SN using qPCR and validated primers. In the pediatric study sample (n = 89), 36% tested positive for the presence of SN, with orthodontic patients comprising more SN-positive samples (87.5%) than SN-negative samples (78.9%), p = 0.0271. In the adult study sample (n = 119), SN was found in 28.6%, with orthodontic patients comprising 58.8% of positive samples and only 28.2% of negative samples (p < 0.0001). These data demonstrated that both pediatric and adult orthodontic patients exhibited higher prevalence of SN compared with age-matched non-orthodontic controls. As this microorganism is associated not only with periodontal disease but also long-term health issues such as obesity, more research is needed regarding the factors that increase the prevalence of this microbe.

Antibacterial Effect of Silver Nanoparticles against Oral Biofilms in Subjects with Motor and Intellectual Disabilities

BACKGROUND

Motor and intellectual disabilities (MIDs) represent a great challenge for maintaining general health due to physical and cognitive limitations, particularly in the maintenance and preservation of oral health. Silver nanoparticles (AgNPs) have emerged as a promising therapeutic tool for bacterial control, including oral biofilms; however, knowledge of the bactericidal effectiveness of oral biofilms from patients with MIDs is insufficient. This study aims to determine the antimicrobial effect of AgNPs on different oral biofilms taken from patients with and without MIDs.

METHODS

Two sizes of AgNPs were prepared and characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Through consecutive sampling, biofilm samples were collected from 17 subjects with MIDs and 20 subjects without disorders. The antimicrobial effect was determined by obtaining the minimum inhibitory concentration (MIC) of AgNPs, and the identification and distribution of oral bacterial species were determined by polymerase chain reaction (PCR). Finally, correlations between sociodemographic characteristics and the antimicrobial levels of AgNPs were also explored. The values of the MIC results were analyzed with IBM-SPSS software (version25) using non-parametric tests for independent groups and correlations, with statistical significance being considered as p < 0.05.

RESULTS

Both sizes of AgNPs exhibited tight particle size distributions (smaller: 10.2 ± 0.7 nm; larger: 29.3 ± 2.3 nm) with zeta potential values (-35.0 ± 3.3 and -52.6 ± 8.5 mV, respectively) confirming the stability that resulted in little to no agglomeration of nanoparticles. Although both sizes of AgNPs had good antimicrobial activity in all oral biofilms, the smallest particles had the best antimicrobial effects on the oral biofilm samples from patients with and without MIDs, even better than chlorhexidine (CHX) (p < 0.05). Likewise, the patients with disabilities showed higher levels of antimicrobial sensitivity to AgNPs compared with CHX (p < 0.05). Although the microorganisms included in the biofilms of females had a statistically higher growth level, the AgNP antimicrobial effect was statistically similar in both genders (p > 0.05). The most frequent bacteria for all oral biofilms were S. mutans (100%), P. intermedia (91.6%), T. forsythia (75.0%), T. denticola (75.0%), P. gingivalis (66.6%), F. nucleatum (66.6%), S. sobrinus (50.0%), and A. actinomycetemcomitans (8.3%).

CONCLUSIONS

AgNPs exhibited considerable antimicrobial potential to be used as a complementary and alternative tool in maintaining and preserving oral health in patients with MIDs.

Subgingival microbial changes in Down Syndrome adults with periodontitis after chlorhexidine adjunct non-surgical therapy and monthly recalls-A 12-month case series study

OBJECTIVES

Down Syndrome (DS) adults are at risk for periodontitis. Previous reports indicated difficulties in periodontopathogen reduction or eradication in DS individuals after periodontal treatment. This case series follows the subgingival microbial changes in adult DS individuals with periodontitis who received chlorhexidine adjunct non-surgical therapy plus 12-month recalls.

METHODS

Twenty periodontitis DS participants (7 females; 25.5 ± 5.6 years of age; 3 with generalized periodontitis) partook in a study involving non-surgical mechanical periodontal therapy, twice daily chlorhexidine gel toothbrushing, chlorhexidine mouthwash, and monthly recalls. The subgingival microbiota profile was followed at baseline, 6-, and 12-months post-operation.

RESULTS

Desulfobulbus, Saccharibacteria (TM7), Tannerella, and Porphyromonas were the major subgingival genera in this DS cohort. Favorable chlorhexidine adjunct non-surgical treatment outcomes were observed, with the relative abundance of Desulfobulbus sp. HMT 041, Saccharibacteria (TM7) [G-1] bacterium HMT 346 or 349, and Tannerella forsythia significantly reduced at the end of the study, but no significant reduction of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans could be observed. Relative abundance of Desulfobulbus sp. HMT 041 and T. forsythia were also found to be significantly associated with plaque, bleeding on probing, and probing pocket depth (PPD, in mm) at a site level, while the relative abundance of Halomonas pacifica was negatively associated with PPD.

CONCLUSIONS

Successful chlorhexidine adjunct non-surgical treatment with hygiene care was accompanied by a subgingival microbial shift involving certain periodontopathogenic species, except P. gingivalis and A. actinomycetemcomitans. Further investigations are required to clarify the mechanism underpinning the unchanged relative abundance of the above two pathogens despite favorable clinical responses.

CLINICAL SIGNIFICANCE

DS adults face challenges achieving optimal home care or hygiene for periodontal healing and disease prevention. Chemical adjunct mechanical periodontal therapy plus regular recalls appeared promising clinically and microbiologically, with subgingival periodontopathogenic species reduction. The persistence of A. actinomycetemcomitans and P. gingivalis in subgingival niches post-treatment warrants further investigation.

Comparison of dental plaque flora between intellectually disabled patients and healthy individuals: a cross-sectional study

Periodontal diseases, including gingivitis, are highly prevalent in individuals with intellectual disability (ID). In particular, gingivitis can be difficult to cure owing to the lack of patient cooperation. Here, we evaluated differences in the oral bacterial flora between individuals with ID (n = 16) and healthy controls (n = 14) to facilitate the development of strategies for the prevention of periodontal disease in people with ID. Our results showed no significant difference in the number of decayed, missing, and filled teeth between the two groups. However, there were significant differences in the median papillary-marginal-attached index, plaque index, and gingival index between groups (P < 0.0001). Additionally, the mean probing depth in the ID group was significantly higher than that in the control group (P < 0.0001). The diversity of oral flora in people with ID and concurrent gingivitis was significantly lower than that of healthy individuals without periodontal disease. The relative abundances of Tannerella spp. and Treponema spp. were significantly higher in the ID group than in the control group at the genus level (P = 0.0383 and 0.0432, respectively), whereas that of Porphyromonas spp. was significantly lower in the ID group (P < 0.0001). Overall, our findings provided important insights into differences in the oral microbiota between patients with ID and healthy controls.

Periodontal disease in down syndrome: Predisposing factors and potential non-surgical therapeutic approaches

BACKGROUND

Periodontal diseases (PDs) have been documented to be significantly more prevalent and severe in patients with Down syndrome (DS). Different immunological and microbiological factors contributed to predisposing these patients to progressive and recurrent PDs.

AIM

The aim of this review was to investigate the altered immunological responses and oral microbiota disorders as well as focus on adjunctive non-surgical methods for the treatment of PDs and its applicability in patients with DS.

MATERIAL AND METHODS

A literature review was conducted addressing the following topics: (1) the altered immunological responses, (2) orofacial disorders related to DS patients, (3) oral microbiota changing, and (4) adjunctive non-surgical treatment and its efficacy in patients with DS.

RESULTS

Due to the early onset of PDs in children with DS, the need for prompt and effective treatment in these patients is essential.

DISCUSSION AND CONCLUSION

So, investigating underlying factors may open a new window to better understand the pathology of PDs in DS people and thus, find better strategies for treatment in such group. Although non-surgical treatments such as photodynamic therapy and probiotic consumption represented acceptable outcomes in different examined patients without DS, data about the application of these convenience and no need for local anesthesia methods in patients with DS is limited.

Salivary microbiome in children with Down syndrome: a case-control study

BACKGROUND

Down syndrome (DS), a most frequently occurring genetic disorder, is associated with oral morphological abnormalities and higher incidence rates of oral diseases. Recent studies have analyzed the oral microbiome to elucidate their relationships with oral diseases and general health; however, reports on the oral microbiome in individuals with DS are scarce. This study aimed to characterize the oral microbiome in children with DS.

METHODS

A total of 54 children aged 1-13 years were enrolled in this case-control study. Of these children, 27 had DS (Case: DS group) and 27 were age-matched healthy children (Control: ND group). Saliva in the oral cavity was collected with a swab, cultured, and tested for cariogenic and periodontopathic bacteria by quantitative polymerase chain reaction (qPCR) detection, and the salivary microbiome was analyzed using next-generation sequencing. The student's t-test, Fisher's exact test, Mann-Whitney U test, and permutational multivariate analysis of variance were used for statistical analysis.

RESULTS

Results of culture and qPCR detection tests for cariogenic and periodontopathic bacteria showed no significant differences in the detected bacteria between the DS and ND groups, with the exception of a significantly higher detection rate of Candida albicans in children with DS with mixed dentition. A comparison of the salivary microbiomes by 16S sequencing showed no significant difference in α diversity; however, it showed a significant difference in β diversity. Children with DS had a higher relative abundance of Corynebacterium and Cardiobacterium, and lower relative abundance of TM7.

CONCLUSIONS

This study provided basic data on the salivary microbiome of children with DS and showed the microbiological markers peculiar to children with DS. However, further research to identify the relationship with oral diseases is warranted.

Oral Microbiota Features in Subjects with Down Syndrome and Periodontal Diseases: A Systematic Review

Down syndrome (DS) is a genetic disorder associated with early-onset periodontitis and other periodontal diseases (PDs). The present work aimed to systematically review the scientific literature reporting studies in vivo on oral microbiota features in subjects with DS and related periodontal health and to highlight any correlation and difference with subjects not affected by DS, with and without PDs. PubMed, Web of Science, Scopus and Cochrane were searched for relevant studies in May 2021. The participants were subjects affected by Down syndrome (DS) with and without periodontal diseases; the study compared subjects with periodontal diseases but not affected by DS, and DS without periodontal diseases; the outcomes were the differences in oral microbiota/periodontopathogen bacterial composition among subjects considered; the study design was a systematic review. Study quality was assessed with risk of bias in non-randomized studies of interventions (ROBINS-I). Of the 954 references retrieved, 26 studies were considered. The conclusions from the qualitative assessment of the papers revealed an increasing knowledge over the last years of the microbiota associated with DS and their periodontal diseases, in comparison with healthy subjects and subjects with other kinds of mental disabilities. Few data have emerged on the mycobiome and virobiome of DS, hence, further investigations are still necessary.

Pre and Probiotics Involved in the Modulation of Oral Bacterial Species: New Therapeutic Leads in Mental Disorders?

This systematic review aims to identify probiotics and prebiotics for modulating oral bacterial species associated with mental disorders. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline, we search the electronic MEDLINE database published till January 2021 to identify the studies on probiotics and/or prebiotics for preventing and treating major oral dysbiosis that provokes mental disorders. The outcome of the search produces 374 records. After excluding non-relevant studies, 38 papers were included in the present review. While many studies suggest the potential effects of the oral microbiota on the biochemical signalling events between the oral microbiota and central nervous system, our review highlights the limited development concerning the use of prebiotics and/or probiotics in modulating oral dysbiosis potentially involved in the development of mental disorders. However, the collected studies confirm prebiotics and/or probiotics interest for a global or targeted modulation of the oral microbiome in preventing or treating mental disorders. These outcomes also offer exciting prospects for improving the oral health of people with mental disorders in the future.

Genetic Susceptibility to Periodontal Disease in Down Syndrome: A Case-Control Study

Severe periodontitis is prevalent in Down syndrome (DS). This study aimed to identify genetic variations associated with periodontitis in individuals with DS. The study group was distributed into DS patients with periodontitis (n = 50) and DS patients with healthy periodontium (n = 36). All samples were genotyped with the “Axiom Spanish Biobank” array, which contains 757,836 markers. An association analysis at the individual marker level using logistic regression, as well as at the gene level applying the sequence kernel association test (SKAT) was performed. The most significant genes were included in a pathway analysis using the free DAVID software. C12orf74 (rs4315121, p = 9.85 × 10⁻⁵, OR = 8.84), LOC101930064 (rs4814890, p = 9.61 × 10⁻⁵, OR = 0.13), KBTBD12 (rs1549874, p = 8.27 × 10⁻⁵, OR = 0.08), PIWIL1 (rs11060842, p = 7.82 × 10⁻⁵, OR = 9.05) and C16orf82 (rs62030877, p = 8.92 × 10⁻⁵, OR = 0.14) showed a higher probability in the individual analysis. The analysis at the gene level highlighted PIWIL, MIR9-2, LHCGR, TPR and BCR. At the signaling pathway level, PI3K-Akt, long-term depression and FoxO achieved nominal significance (p = 1.3 × 10⁻², p = 5.1 × 10⁻³, p = 1.2 × 10⁻², respectively). In summary, various metabolic pathways are involved in the pathogenesis of periodontitis in DS, including PI3K-Akt, which regulates cell proliferation and inflammatory response.

Streptococci in the Subgingival Biofilm and Periodontal Therapy

Purpose: The aim of this study was to verify how the prevalence of viridans-streptococci is changed by two appointments of professional prophylaxis and after the subgingival instrumentation via scaling and root planing (SRP). Material and Methods: Samples of the subgingival biofilm were collected from 19 individuals with periodontitis receiving two appointments of professional prophylaxis and SRP before and after the treatment procedures and the presence of viridans-streptococci was analysed by microbiological cultivation. Non-parametric statistical testing using Friedman/Wilcoxon tests and chi-square testing was used for statistical analysis. Results: No statistically significant changes over time were found for the mutans-group. The prevalence of Streptococcus mitis decreased after two appointments of professional prophylaxis (p = 0.013). The prevalence of S. mitis decreased again after SRP (p <0.001). The prevalence of Streptococcus anginosus decreased after two appointments of professional prophylaxis (p = 0.002). After SRP five positive results for S. anginosus were detected (p = 0.026). For Streptococcus oralis and Streptococcus gordonii tendencies to statistical significance were found. The number of positive results for S. oralis increased after the first appointment of professional oral prophylaxis (p = 0.055). The number of positive results for S. gordonii increased after the first appointment of professional oral prophylaxis (p = 0.055). Conclusion: The step-wise periodontal therapy influences the prevalence of viridans-streptococci, especially S. mitis and S. anginosus. No tremendous increase of streptococci especially related to the carious process occurs in the subgingival biofilm. Clinical Relevance: The study reveals knowledge on changes of the composition of the subgingival biofilm due to different steps of periodontal therapy.

Oral microbiome in down syndrome and its implications on oral health

Introduction: The oral cavity harbors an abundant and diverse microbial community (i.e. the microbiome), whose composition and roles in health and disease have been the focus of intense research. Down syndrome (DS) is associated with particular characteristics in the oral cavity, and with a lower incidence of caries and higher incidence of periodontitis and gingivitis compared to control populations. However, the overall composition of the oral microbiome in DS and how it varies with diverse factors like host age or the pH within the mouth are still poorly understood. Methods: Using a Citizen-Science approach in collaboration with DS associations in Spain, we performed 16S rRNA metabarcoding and high-throughput sequencing, combined with culture and proteomics-based identification of fungi to survey the bacterial and fungal oral microbiome in 27 DS persons (age range 7–55) and control samples matched by geographical distribution, age range, and gender.

Results: We found that DS is associated with low salivary pH and less diverse oral microbiomes, which were characterized by lower levels of Alloprevotella, Atopobium, Candidatus Saccharimonas, and higher amounts of Kingella, Staphylococcus, Gemella, Cardiobacterium, Rothia, Actinobacillus, and greater prevalence of Candida.

Conclusion: Altogether, our study provides a first global snapshot of the oral microbiome in DS. Future studies are required to establish whether the observed differences are related to differential pathology in the oral cavity in DS.

Did the Brain and Oral Microbiota Talk to Each Other? A Review of the Literature

This systematic review aims to investigate the role of the oral microbiome in the pathophysiology of mental health disorders and to appraise the methodological quality of research of the oral–brain axis which is a growing interest area. The PRISMA guideline was adopted, to carry out an electronic search through the MEDLINE database, to identify studies that have explored the role of the oral microbiome in the pathophysiology of mental health disorders published from 2000 up to June 2020. The search resulted in 140 records; after exclusions, a total of 22 papers were included in the present review. In accordance with the role of the oral microbiome in the pathophysiology of mental disorders, four mental disorders were identified: Alzheimer’s disease, dementia, and cognitive disorders; autism spectrum disorder; Down’s syndrome and mental retardation; and Bipolar disorders. Studies argue for correlations between oral microbiota and Alzheimer’s disease, autism spectrum disorders, Down’s syndrome, and bipolar disorders. This field is still under-studied, and studies are needed to clarify the biological links and interconnections between the oral microbiota and the pathophysiology of all mental health disorders. Researchers should focus their efforts to develop research on the oral–brain axis in the future.

The Subgingival Microbiome in Patients with Down Syndrome and Periodontitis

Objective: To describe the subgingival microbiome of individuals with Down syndrome (DS). Methods: We conducted a cross-sectional observational study that obtained bacterial DNA samples from 50 patients with DS, 25 with periodontitis (PDS) and 25 with a healthy periodontal condition (HDS). The samples were analyzed by sequencing the 16S rRNA gene V3–V4 hypervariable region using the MiSeq System. Taxonomic affiliations were assigned using the naïve Bayesian classifier integrated in QIIME2 plugins. We evaluated the difference in bacteria abundance between the sample groups using Wilcoxon and Kruskal–Wallis tests. We evaluated the alpha diversity of the identified species using the Observed, Chao1metric, ACE and Shannon indices and evaluated beta diversity with principal coordinate analysis (registration code: 2018/510). Results: Twenty-one genera and 39 bacterial species showed a significantly different abundance between the study groups. Among the genera, Porphyromonas, Treponema, Tannerella and Aggregatibacter were more abundant in the PDS group than in the HDS group, as were the less commonly studied Filifactor, Fretibacterium and Desulfobulbus genera. Among the species, Porphyromonas spp. and Tannerella spp. were the most abundant in the PDS group; the most abundant species in the HDS group were Pseudomonas spp., Granulicatella spp. and Gemella spp. Conclusion: Well-recognized periodontal pathogens and newly proposed pathogenic taxa were associated with periodontitis in patients with DS.

Differential Expression of Inflammation-Related Genes in Down Syndrome Patients with or without Periodontal Disease

Aim

Aware that Down Syndrome patients present among their clinical characteristics impaired immunity, the aim of this study is to identify the statistically significant differences in inflammation-related gene expression by comparing Down Syndrome patients with Periodontal Disease (DS+PD+) with Down Syndrome patients without Periodontal Disease (DS+PD-), and their relationship with periodontitis as a chronic oral inflammatory clinical feature.

Materials and Methods

Case study and controls on eleven Down Syndrome patients (DS+PD+ vs. DS+PD-). RNA was extracted from peripheral blood using a Qiagen PAXgene Blood miRNA Kit when performing an oral examination. A search for candidate genes (92 selected) was undertaken on the total genes obtained using a Scientific GeneChip® Scanner 3000 (Thermo Fisher Scientific) and Clariom S solutions for human, mouse, and rat chips, with more than 20,000 genes annotated for measuring expression levels.

Results

Of the 92 inflammation-related genes taken initially, four genes showed a differential expression across both groups with a p value of <0.05 from the data obtained using RNA processing of the patient sample. Said genes were TNFSF13B (p = 0.0448), ITGB2 (p = 0.0033), ANXA3 (p = 0.0479), and ANXA5 (p = 0.016).

Conclusions

There are differences in inflammation-related gene expression in Down Syndrome patients when comparing patients who present a state of chronic oral inflammation with patients with negative rates of periodontal disease.

Periodontal status of individuals with Down syndrome: sociodemographic, behavioural and family perception influence

BACKGROUND

The aim of the present study was to assess the periodontal condition of individuals with Down syndrome and the association with sociodemographic and behavioural characteristics and family perception of oral health.

METHODS

This cross-sectional observational study was performed at a referral centre for dental assistance to disabled persons in Araçatuba, Brazil. Parents of the individuals were interviewed, and the visible plaque index, bleeding on probing, probing pocket depth and clinical attachment level were recorded by one periodontist in six sites per tooth of all teeth. The individual was the unit of analysis. The significance level was set at 5%.

RESULTS

Sixty-four subjects (23.8 ± 8.3 years old) were included. Eighteen (28.1%) were diagnosed with gingivitis and 46 (71.9%) with periodontitis. In the multiple logistic regression final model, age and self-reported oral hygiene practices were associated with the occurrence of periodontitis. The chance of having periodontitis was 4.7 times higher among individuals older than 20 years and approximately 4 times higher in patients whose oral hygiene was performed by themselves and their parents, compared with those who performed oral hygiene alone. Sex, follow-up time in the centre, education, degree of participants' dependence, flossing and family history of periodontal disease were not associated with the occurrence of periodontitis. Higher levels of plaque and bleeding were observed for participants with parents reporting bad gingival health (76.2% and 46.9%) and deficient oral hygiene (79.5% and 47.3%). The perception of parents regarding gingival bleeding was correlated with higher bleeding detected clinically (P = 0.01; 50.1%).

CONCLUSIONS

The prevalence of periodontitis in individuals with Down syndrome is high and increases with age, even in the face of the parents' perception about their children's oral condition.

The Dental Needs and Treatment of Patients with Down Syndrome

Down syndrome is a common disorder with many oral conditions and systemic manifestations. Dentists need to take a holistic approach including behavioral, oral, and systemic issues. This review of the literature focuses on oral anomalies, systemic interaction, management, and recommendations.

Reported gum disease as a cardiovascular risk factor in adults with intellectual disabilities

BACKGROUND

Several risk factors for cardiovascular disease (CVD) have been identified among adults with intellectual disabilities (ID). Periodontitis has been reported to increase the risk of developing a CVD in the general population. Given that individuals with ID have been reported to have a higher prevalence of poor oral health than the general population, the purpose of this study was to determine whether adults with ID with informant reported gum disease present greater reported CVD than those who do not have reported gum disease and whether gum disease can be considered a risk factor for CVD.

METHODS

Using baseline data from the Longitudinal Health and Intellectual Disability Study from which informant survey data were collected, 128 participants with reported gum disease and 1252 subjects without reported gum disease were identified. A series of univariate logistic regressions was conducted to identify potential confounding factors for a multiple logistic regression.

RESULTS

The series of univariate logistic regressions identified age, Down syndrome, hypercholesterolemia, hypertension, reported gum disease, daily consumption of fruits and vegetables and the addition of table salt as significant risk factors for reported CVD. When the significant factors from the univariate logistic regression were included in the multiple logistic analysis, reported gum disease remained as an independent risk factor for reported CVD after adjusting for the remaining risk factors. Compared with the adults with ID without reported gum disease, adults in the gum disease group demonstrated a significantly higher prevalence of reported CVD (19.5% vs. 9.7%; P = .001).

CONCLUSION

After controlling for other risk factors, reported gum disease among adults with ID may be associated with a higher risk of CVD. However, further research that also includes clinical indices of periodontal disease and CVD for this population is needed to determine if there is a causal relationship between gum disease and CVD.

MeDIP Real-Time qPCR has the Potential for Noninvasive Prenatal Screening of Fetal Trisomy 21

This study aimed to verify the reliability of the 7 tissue differentially methylated regions used in the methylated DNA immunoprecipitation (MeDIP) real- time quantitative polymerase chain reaction (real-time qPCR) based approach of fetal DNA in maternal blood to diagnosis of fetal trisomy 21. Forty pregnant women with high risk pregnancy who were referred after first or second trimester screening tests, were selected randomly. For each sample whole DNA extraction (mother and fetus), fragmentation of DNA, immunoprecipitation of methylated DNA and real- time qPCR using 7 primer pairs was performed. D-value for each sample was calculated using the following formula D = -4.908+ 0.254 X_EP1+ 0.409 X_EP4+ 0.793 X_EP5+ 0.324 X_EP6+ 0.505 X_EP7+ 0.508 X_EP9+ 0.691 X_EP12. In all normal cases, D value was negative, while it was positive in all trisomy cases. Therefore, all normal and trisomy 21 cases were classified correctly which correspond to 100% specificity and 100% sensitivity for this method. The MeDIP real-time qPCR method has provided the opportunity for noninvasive prenatal diagnosis of fetal trisomy 21 to be potentially employed into the routine practice of diagnostic laboratories.

Integrated analysis of DNA methylation and RNA‑sequencing data in Down syndrome

Down syndrome (DS) is the most common birth defect in children. To investigate the mechanisms of DS, the present study analyzed the bisulfite‑sequencing (seq) data GSE42144, which was downloaded from the Gene Expression Omnibus. GSE42144 included DNA methylation data of three DS samples and three control samples, and RNA‑seq data of two DS samples and five control samples. The methylated sites in the bisulfite‑seq data were detected using Bismark and Bowtie2. The BiSeq tool was applied to determine differentially methylated regions and to identify adjacent genes. Using the Database for Annotation, Visualization and Integrated Discovery, the functions of the abnormal demethylated genes were predicted by functional enrichment analyses. Differentially expressed genes (DEGs) were then screened using a paired t‑test. Furthermore, the interactions of the proteins encoded by selected genes were determined using the Search Tool for the Retrieval of Interacting Genes, and a protein‑protein interaction (PPI) network was constructed using Cytoscape. A total of 74 CpG regions showed significant differential DNA methylation between the DS and normal samples. There were five abnormal demethylated DNA regions in chromosome 21. In the DS samples, a total of 43 adjacent genes were identified with demethylation in their promoter regions and one adjacent gene was identified with upregulated methylation in its promoter regions. In addition, 584 upregulated genes were identified, including 24 genes with transcriptional regulatory function. In particular, upregulated Runt‑related transcription factor 1 (RUNX1) was located on chromosome 21. Functional enrichment analysis indicated that inhibitor of DNA binding 4 (ID4) was involved in neuronal differentiation and transcriptional suppression. In the PPI network, genes may be involved in DS by interacting with others, including nuclear receptor subfamily 4 group A member 2 (NR4A2)‑early growth response (EGR)2 and NR4A2‑EGR3. Therefore, RUNX1, NR4A2, EGR2, EGR3 and ID4 may be key genes associated with the pathogenesis of DS.

Salivary Periodontopathic Bacteria in Children and Adolescents with Down Syndrome

OBJECTIVE

To assess and compare salivary periodontopathic bacteria between groups of Down syndrome and non-Down syndrome children and adolescents.

MATERIALS AND METHODS

This study included a sample of 30 Down syndrome children and adolescents (G-DS) and 30 age- and sex-matched non-Down syndrome subjects (G-ND). Clinical examination determined the gingival bleeding index (GBI) and plaque index. Unstimulated whole saliva samples were collected from all participants. The fluorescence in situ hybridization (FISH) technique identified the presence and density of eight periodontopathic bacteria in saliva. The statistical analysis included chi-square and Mann-Whitney U tests.

RESULTS

In the G-DS group, bleeding on probing was more frequent (p = 0.037) and higher densities of Campylobacter rectus (p = 0.013), Porphyromonas gingivalis (p = 0.025), Treponema denticola (p = 0.026), Fusobacterium nucleatum (p = 0.013), Prevotella intermedia (p = 0.001) and Prevotella nigrescens (p = 0.008) were observed. Besides, in the G-DS, the densities of bacteria from the orange complex were significantly higher in the age group 3-7 years for F. nucleatum (p = 0.029), P. intermedia (p = 0.001) and P. nigrescens (p = 0.006). C. rectus was higher in the age group 8-12 years (p = 0.045).

CONCLUSION

The results showed that children and adolescents with Down syndrome have higher susceptibility to periodontal disease and number of periodontopathic bacteria.

Periodontal disease's contribution to Alzheimer's disease progression in Down syndrome

People with Down syndrome (DS) are at an increased risk for Alzheimer's disease (AD). After 60 years of age, >50% of DS subjects acquire dementia. Nevertheless, the age of onset is highly variable possibly because of both genetic and environmental factors. Genetics cannot be modified, but environmental risk factors present a potentially relevant intervention for DS persons at risk for AD. Among them, inflammation, important in AD of DS type, is potential target. Consistent with this hypothesis, chronic peripheral inflammation and infections may contribute to AD pathogenesis in DS. People with DS have an aggressive form of periodontitis characterized by rapid progression, significant bacterial and inflammatory burden, and an onset as early as 6 years of age. This review offers a hypothetical mechanistic link between periodontitis and AD in the DS population. Because periodontitis is a treatable condition, it may be a readily modifiable risk factor for AD.

Effect on plaque control in children patients with Down syndrome using Digital Brush with or without chlorhexidine: a randomized clinical trial

OBJECTIVES

The aim of this study was to evaluate efficacy in children affected by Down syndrome of "Digital Brush" in terms of Plaque Index reduction added to the daily oral hygiene procedures.

METHODS

A total of 56 patients with Down syndrome were recruited and randomly assigned in two groups: both control and test groups underwent standard hygiene procedures of tooth brushing twice a day followed by the intervention of Digital Brush, TNT gauze impregnated with chlorhexidine 0.12%, for the test group and by sterile gauze soaked in water for the control group. Initial plaque index was measured for all patients (T0), subsequently were instructed to use either Digital Brush or gauze soaked with water for 2 weeks. At last, patients were reevaluated (T1) and the plaque index measured.

RESULTS

Plaque index improvement from T0 to T1 in control group was 11.7%, while in test group was 24.1%. The mean differences between test and control group was statistically significant (p < 0.001).

CONCLUSIONS

This study demonstrates how the Digital Brush, added to the daily oral hygiene procedures, obtains significant improvements in supragingival plaque control in children with Down syndrome.

Oral cleanliness and gingival health among Special Olympics athletes in Europe and Eurasia

Background

Special Olympics athletes, as well as the general population of people with intellectual disabilities, are expected to have poorer gingival health. The aim of the study is to explore the prevalence of gingival signs of inflammation and its relationship to oral cleanliness and age among Special Olympics athletes from Europe and Eurasia.

Material and Methods

A retrospective longitudinal study was performed with data collected through standardized oral from 15.941 athletes from annual Special Olympics events held in 49 countries, from Europe and Eurasia between 2007 and 2012. The data was analysed descriptively, with One-Way ANOVA test and Chi-Square test.

Results

The level of significance was predetermined at a p value < 0.05. A total of 7,754 athletes presented with gingival signs (48.64%). There were no significant differences (p= 0,095) in mean gingival signs between age groups, however the association between mouth cleaning and age, was statistically significant.

Conclusions

The data suggests that there is a high prevalence of gingival signs among individuals with special needs; over 50% in more than 20 countries. Therefore, there is a serious need for education and preventive programs for the patients, their parents and caregivers.

Key words:Gingivitis, prevalence, hygiene, disability, Special Olympics.

Inter-Individual Differences in the Oral Bacteriome Are Greater than Intra-Day Fluctuations in Individuals

Given the advent of massively parallel DNA sequencing, human microbiome is analyzed comprehensively by metagenomic approaches. However, the inter- and intra-individual variability and stability of the human microbiome remain poorly characterized, particularly at the intra-day level. This issue is of crucial importance for studies examining the effects of microbiome on human health. Here, we focused on bacteriome of oral plaques, for which repeated, time-controlled sampling is feasible. Eighty-one supragingival plaque subjects were collected from healthy individuals, examining multiple sites within the mouth at three time points (forenoon, evening, and night) over the course of 3 days. Bacterial composition was estimated by 16S rRNA sequencing and species-level profiling, resulting in identification of a total of 162 known bacterial species. We found that species compositions and their relative abundances were similar within individuals, and not between sampling time or tooth type. This suggests that species-level oral bacterial composition differs significantly between individuals, although the number of subjects is limited and the intra-individual variation also occurs. The majority of detected bacterial species (98.2%; 159/162), however, did not fluctuate over the course of the day, implying a largely stable oral microbiome on an intra-day time scale. In fact, the stability of this data set enabled us to estimate potential interactions between rare bacteria, with 40 co-occurrences supported by the existing literature. In summary, the present study provides a valuable basis for studies of the human microbiome, with significant implications in terms of biological and clinical outcomes.

Uncovering the molecular networks in periodontitis

Periodontitis is a complex immune-inflammatory disease that results from a preestablished infection in gingiva, mainly due to Gram-negative bacteria that colonize deeper in gingival sulcus and latter periodontal pocket. Host inflammatory and immune responses have both protective and destructive roles. Although cytokines, prostaglandins, and proteases struggle against microbial burden, these molecules promote connective tissue loss and alveolar bone resorption, leading to several histopathological changes, namely destruction of periodontal ligament, deepening of periodontal pocket, and bone loss, which can converge to attain tooth loss. Despite the efforts of genomics, transcriptomics, proteomics/peptidomics, and metabolomics, there is no available biomarker for periodontitis diagnosis, prognosis, and treatment evaluation, which could assist on the established clinical evaluation. Nevertheless, some genes, transcripts, proteins and metabolites have already shown a different expression in healthy subjects and in patients. Though, so far, 'omics approaches only disclosed the host inflammatory response as a consequence of microbial invasion in periodontitis and the diagnosis in periodontitis still relies on clinical parameters, thus a molecular tool for assessing periodontitis lacks in current dental medicine paradigm. Saliva and gingival crevicular fluid have been attracting researchers due to their diagnostic potential, ease, and noninvasive nature of collection. Each one of these fluids has some advantages and disadvantages that are discussed in this review.

The role of microbiome in central nervous system disorders

Mammals live in a co-evolutionary association with the plethora of microorganisms that reside at a variety of tissue microenvironments. The microbiome represents the collective genomes of these co-existing microorganisms, which is shaped by host factors such as genetics and nutrients but in turn is able to influence host biology in health and disease. Niche-specific microbiome, prominently the gut microbiome, has the capacity to effect both local and distal sites within the host. The gut microbiome has played a crucial role in the bidirectional gut-brain axis that integrates the gut and central nervous system (CNS) activities, and thus the concept of microbiome-gut-brain axis is emerging. Studies are revealing how diverse forms of neuro-immune and neuro-psychiatric disorders are correlated with or modulated by variations of microbiome, microbiota-derived products and exogenous antibiotics and probiotics. The microbiome poises the peripheral immune homeostasis and predisposes host susceptibility to CNS autoimmune diseases such as multiple sclerosis. Neural, endocrine and metabolic mechanisms are also critical mediators of the microbiome-CNS signaling, which are more involved in neuro-psychiatric disorders such as autism, depression, anxiety, stress. Research on the role of microbiome in CNS disorders deepens our academic knowledge about host-microbiome commensalism in central regulation and in practicality, holds conceivable promise for developing novel prognostic and therapeutic avenues for CNS disorders.

Oxidative burst intensity of peripheral phagocytic cells and periodontitis in Down syndrome

BACKGROUND

This study investigated the oxidative burst function of peripheral phagocytic cells (granulocytes and monocytes) and assessed the relation between oxidative burst and periodontal status in adult individuals with Down syndrome (DS) vs. other groups.

METHODS

Of 55 DS individuals (18-56 years old), 74 individuals with mental retardation (MR) and 88 medically healthy controls (HC) participated in the study. The MR and HC groups were age, race and gender matched with the DS group. Gingival index, plaque index, probing depth, attachment level and bleeding on probing were recorded for each subject. Whole blood was collected for granulocyte/monocyte oxidative burst tests. Oxidative burst was determined by flow cytometry in terms of percentage of cells actively involved in oxidative burst, and oxidative intensity (magnitude of ROIs per cell).

RESULTS

The basal oxidative burst intensity of DS granulocytes was higher than that of HC and MR granulocytes (p = 0.05). The Escherichia coli stimulated oxidative burst intensity of DS monocytes was higher than that of HC and MR monocytes (p = 0.05). Regression analysis controlling for age, sex, race and plaque levels showed a significant association between monocyte oxidative burst intensity and loss of periodontal attachment in DS subjects (p < 0.01). Regression analysis also showed a significant association between granulocyte oxidative burst intensity and bleeding on probing in all subjects (p < 0.05).

CONCLUSIONS

Oxidative burst activity of peripheral monocytes and granulocytes is elevated in DS affected individuals and may contribute to periodontal tissue inflammation and loss of periodontal attachment in this susceptible group.