Periodontitis In Adolescents Research Articles

Risk of periodontitis in adolescents with bipolar disorder: a cohort study of 21,255 subjects.

Although a growing number of studies have investigated the relationship between psychosocial factors and periodontitis, studies investigating the association between bipolar disorder (BD) and periodontitis are lacking. Using the Taiwan National Health Insurance Research Database, 4251 adolescents with BD and 17,004 age- and sex-matched controls were included. They were followed up from enrollment to the end of 2011 or death. Periodontitis was diagnosed during the follow-up. Cox regression analysis indicated that adolescents with BD had a higher risk of periodontitis (hazard ratio [HR]: 2.96, 95% confidence interval [CI] 2.77-3.17) than did controls. Subanalyses stratified by sex revealed a higher risk of periodontitis in male (HR: 2.83, 95% CI 2.56-3.14) and female (HR: 3.01, 95% CI 2.74-3.30) adolescents with BD than their respective controls. The long-term use of mood stabilizers was associated with a higher risk of periodontitis (HR: 1.19, 95% CI 1.06-1.35) in the BD cohort. Our study highlighted an increased risk of periodontitis in adolescents with BD compared with controls during the follow-up. We recommend that more attention should be paid to the prevention of periodontitis in adolescents with BD, especially those who are female or receiving mood stabilizers.

Radiographic and clinical signs of periodontitis and associated bacterial species in a Swedish adolescent population.

Periodontitis in adolescents has historically been rare in the Nordic countries but could be expected to increase due to changing demographics. The primary aim was to cross-sectionally examine the presence of radiographic bone loss in adolescents in Västerbotten County, Sweden. The secondary aim was to compare periodontal and microbial parameters, as well as demographic patterns, between controls without bone loss and cases with bone loss. Adolescents born in 2001 who had a dental examination in 2016 (n= 1656) were screened for proximal bone loss using bitewing radiographs taken during dental examinations (2014-2016). Individuals exhibiting proximal bone loss (>2 mm) were invited to participate in a complete periodontal examination. Subgingival plaque and saliva were also sampled. For each adolescent with bone loss, two healthy individuals as controls were examined. Selected bacterial species in saliva and subgingival plaque were examined by quantitative PCR. The subgingival plaque samples were also analyzed via cultivation technique. Proximal bone loss was identified in 24 individuals (1.45%) based on the radiographs. Thirteen of these cases were periodontally examined and matched with 26 controls. Most cases were diagnosed with periodontitis (12/13 [92%]), whereas none of the controls had periodontitis. Higher concentrations and higher prevalence of the bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Filifactor alocis were generally found in the cases. The results suggest that periodontitis is increasing among adolescents in Sweden because of demographic differences (an increasingly heterogenous population), and emphasize the importance of radiographs for early detection of this disease.

Hermansky-Pudlak syndrome type 2: A rare cause of severe periodontitis in adolescents-A case study.

Background and aimsHermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by oculocutaneous albinism (OCA) and platelet storage pool deficiency. The HPS-2 subtype is distinguished by neutropenia, and little is known about its periodontal phenotype in adolescents. AP3B1 is the causative gene for HPS-2. A 13-year-old Chinese girl presented to our department suffering from gingival bleeding and tooth mobility. Her dental history was otherwise unremarkable. Suspecting some systemic diseases as the underlying cause, the patient was referred for medical consultation, a series of blood tests, and genetic tests. In this case study, periodontal status and mutation screening of one HPS-2 case are presented.MethodsBlood analysis including a complete blood count (CBC) and glycated hemoglobin levels were measured. Platelet transmission electron microscopy (PTEM) was performed to observe the dense granules in platelets. Whole-exome sequencing (WES) and Sanger sequencing were performed to confirm the pathogenic variants.ResultsA medical diagnosis of HPS-2 was assigned to the patient. Following the medical diagnosis, a periodontal diagnosis of “periodontitis as a manifestation of systemic disease” was assigned to the patient. We identified novel compound heterozygous variants in AP3B1 (NM_003664.4: exon7: c.763C>T: p.Q255*) and (NM_003664.4: exon1: c.53_56dup: p.E19Dfs*21) in this Chinese pedigree with HPS-2.ConclusionThis case study indicates the importance of periodontitis as a possible indicator of underlying systemic disease. Systemic disease screening is needed when a young patient presents with unusual, severe periodontitis, as the oral condition may be the first of a systemic abnormality. Our work also expands the spectrum of AP3B1 mutations and further provides additional genetic testing information for other HPS-2 patients.

Precursors of insulin resistance underlying periodontitis in adolescents aged 17-18 years.

To investigate the association between insulin resistance markers and periodontitis in adolescents, analyzing confounder variables and the adiposity as a mediator. This is population-based study is representative of adolescents aged 17-18 years from public schools in São Luís, Brazil (n= 405). Insulin resistance was assessed using the Model of Assessment of the Homeostasis of the Insulin Resistance Index (HOMA-IR) and its percussor triglycerides/HDL-cholesterol ratio (TG/HDL-c). The outcome was Initial Periodontitis, a latent variable estimated by the common variance shared among bleeding on probing, probing depth ≥ 4 mm, and clinical attachment loss ≥ 4 mm. The association between insulin resistance and Initial Periodontitis was modeled via pathways triggered by socioeconomic status, smoking, alcohol, and Adiposity, using structural equation modeling. Higher TG/HDL-c was directly associated with higher Initial Periodontitis (standardized coefficient [SC]=0.130, p< 0.001). HOMA-IR was not associated with periodontal outcome (SC=0.023, p= 0.075), but it was with Adiposity (SC=0.495, p< 0.001). Higher TG/HDL-c was associated with Adiposity (SC=0.202, p< 0.001). The insulin resistance markers were associated with early signs of periodontal breakdown among adolescents, suggesting a possible relationship between diabetes and periodontitis commences early in life.

Implementing of aMMP-8 point-of-care test with a modified new disease classification in Finnish adolescent cohorts.

ObjectivesPeriodontitis is a multifactorial biofilm‐induced inflammatory disease; however, clinical and radiographic information reflects events that have already occurred. aMMP‐8 lateral‐flow chairside or point‐of‐care‐test (POC‐test) results have also come to complement the overall status of the patient's current situation. The current study aimed to clarify the usefulness of aMMP‐8 chairside‐test (aMMP‐8 POCT) results to alert the initial or early periodontitis in adolescents, a potential periodontitis risk group with cut off 20 ng/ml in Stage I periodontitis, according to the current periodontitis classification system.Material and MethodsA total of 117 adolescents were aMMP‐8 POC tested for aMMP‐8 levels and examined for the full mouth and were interviewed for questions concerning health behavior.ResultsOf all 117 participants, N = 38 (32.5%) was aMMP‐8 POCT positive, and N = 34 (29.1%) had at least one 4 mm periodontal deepened pocket; however, only N = 16 (13.7%) had both characteristics. The subclinical stage (N = 47) could not be classified either as gingivitis or Stage I. Of the participants, who did not have any deepened periodontal pockets, 18 tested negative.ConclusionsStage I is preceded by antecedent stages that should be tackled by oral healthcare prevention and personalized treatment modalities by professionals. Elevated (>20 ng/ml), positive aMMP‐8 POCT results can be regarded as initial alarmer such as emerging risk. This should be utilized in the preventive personalized interventions by oral health professionals.

Investigating oral and systemic pathways between unhealthy and healthy dietary patterns to periodontitis in adolescents: A population-based study.

To investigate pathways between unhealthy and healthy dietary patterns and periodontitis in adolescents (18-19 years of age). This population-based study (n= 2515) modelled direct and mediated pathways (via biofilm and obesity) from patterns of healthy diet (fruits, fibre, vegetables, and dairy) and unhealthy diet (sugars, snacks, and salty/fast foods) with initial periodontitis (bleeding on probing [BoP], probing depth [PD] ≥ 4 mm, clinical attachment loss [CAL] ≥ 4 mm), moderate periodontitis (BoP, PD ≥ 5 mm, and CAL ≥ 5 mm), and European Federation of Periodontology and the American Academy of Periodontology (EFP-AAP) periodontitis definitions, adjusting for sex, socio-economic status, smoking, and alcohol, through structural equation modelling (α= 5%). Higher values of healthy diet were associated with lower values of initial periodontitis (standardized coefficient [SC]=-0.160; p< .001), moderate periodontitis (SC=-0.202; p< .001), and EFP-AAP periodontitis (p< .05). A higher value of unhealthy diet was associated with higher values of initial periodontitis (SC=0.134; p= .005) and moderate periodontitis (SC=0.180; p< .001). Biofilm mediated the association between higher values of unhealthy diet and all periodontal outcomes (p< .05). Our findings suggest that both healthy and unhealthy dietary patterns may contribute to reduced or increased extent and severity of periodontitis by local and systemic mechanisms, preceding the effect of other established causes such as smoking and obesity, in younger population.

Candida albicans and Candida dubliniensis in Periodontitis in Adolescents and Young Adults

Aim This study aims to evaluate the association of Candida albicans and Candida dubliniensis with periodontitis in adolescents and young adults in a Moroccan population. Methods 426 subjects aged between 12 and 25 years were recruited for the study. A pool of plaque sample was taken. Samples were cultured on Sabouraud Chloramphenicol medium at 37°C for 24–48 hours and then identified by the Vitek 2 YST system. Clinical data and presence of Candida albicans and Candida dubliniensis were analyzed using Jamovi (Version 1.8). Results Candida albicans was observed in 25 subjects among 68 diseased patients (37%) and in 60 subjects among 358 healthy patients (17%). It can be reported that under normal yeast conditions, there is a statistically significant difference between these two groups (P < 0.001). Candida dubliniensis was more prevalent in periodontitis than in healthy subjects (P=0.026). Regarding clinical variables, subgroups of periodontitis subjects showed significant statistical differences for periodontal probing depth, clinical attachment loss, and number of decayed teeth in advanced periodontitis in comparison with initial or mild periodontitis. The results also indicate that the presence of the two species of Candida is not related to gender or age (P > 0.05) nor related to the severity of the periodontal disease in this population. Conclusion Within the limits of our study, Candida albicans is more frequently associated with periodontitis. The potential role of C. albicans in periodontitis pathogenesis is very complex. More studies on biofilm associated with different forms of periodontitis are necessary. It is also important to assess the coexistence of periodontitis and caries and the associated biofilms.

Performance of the 2017 AAP/EFP case definition compared with the CDC/AAP definition in population-based studies.

Classification of the periodontal conditions is indispensable for epidemiological data in order to guide situational awareness and therapeutic strategies. The new classification of periodontal diseases and conditions introduced by the American Academy of Periodontology and the European Federation of Periodontology (AAP/EFP), however, has not yet been applied to population-based studies. The aim of the present study was to compare the prevalence of periodontitis between the AAP/EFP and the CDC/AAP classification system and to evaluate the accuracy of the new AAP/EFP classification system against the CDC/AAP case definition for population-based studies. Epidemiological data from two cross-sectional studies were obtained. One of them was a population-based study on Chilean adults (1.456 individuals; 35-44 years; 65-74 years) and the other one a sample of adolescents (1.070 individuals; 15-19 years) from five countries; Argentina, Chile, Colombia, Ecuador, and Uruguay. All participants had undergone full-mouth periodontal examination by calibrated examiners. Epidemiological datasets were analyzed according to the AAP/EFP and the CDC/AAP case definitions. The accuracy of the AAP/EFP definition was examined by assessing the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating curve (ROC) using the CDC/AAP case definition as the reference standard. According to the AAP/EFP, the prevalence of periodontitis in adolescents was 75.6%. The majority of the adolescents were classified either as Stage I (39.2%) or Stage II (28.2%). By using the CDC/AAP classification the prevalence of periodontitis in adolescents was 27.2%. The most common form of periodontitis with the CDC/AAP classification was moderate periodontitis (15.3%) followed by mild periodontitis (11.4%). The AAP/EFP revealed high sensitivity in moderate (95.7%) and severe periodontitis (100%) as well as a moderate (75%) to high specificity (92%) in moderate and severe periodontitis, respectively. The PPV was 41.6% in moderate and 5.7% in severe periodontitis whereas the NPV was high in both categories (moderate=99%; severe=100%). The AUC was 0.91 (95% CI=0.89-0.93). In adults, the prevalence of periodontitis was 99% according to the AAP/EFP. The majority of adults were classified as Stage IV (81.3%) whereas Stage III amounted to 12.8%. By using the CDC/AAP classification, the prevalence of periodontitis in adults was 88.3% and the most common form of periodontitis was moderate periodontitis (57.2%) followed by severe periodontitis (29.7%). In adults, the AAP/EFP revealed high sensitivity for moderate (99.7%) and severe periodontitis (100%), but low specificity for both categories (moderate=6.8%; severe=8.3%). The PPV was 88.7% in moderate and 31.7% in severe periodontitis. The NPV was high in both categories (moderate=76.5%; severe=100%). The AUC was 0.57 (95% CI=0.53-0.62). This study revealed a clear discrepancy in the prevalence of periodontitis between the AAP/EFP and the CDC/AAP classification when using epidemiological data. The 2017 AAP/EFP classification system performs well when compared to the CDC/AAP case definition in identifying adolescents with periodontitis. The AAP/EFP system seems less accurate in adults with high prevalence of periodontitis.

Aggregatibacter actinomycetemcomitans and Aggregatibacter aphrophilus in a Kenyan Maasai Adolescent Population and Inhibition of Leukotoxic Activity by Herbal Plants Used as Part of Oral Hygiene Procedures.

Background: A virulent genotype (JP2) of the periodonto-pathogen, Aggregatibacter actinomycetemcomitans (Aa), is widespread in North and West Africa, while its presence in East Africa has not been thoroughly investigated. This JP2 genotype is associated with periodontitis in adolescents and has a high leukotoxicity. The aim of the study was to examine the prevalence of Aa and its JP2 genotype, the prevalence of the oral, commensal Aggregatibacter aphrophilus in a Maasai adolescent population, and the effect of herbal plants for inhibition of leukotoxicity. Methods: A total of 284 adolescents from Maasai Mara, Kenya, underwent an oral examination and microbial sampling. The presence of Aa and A. aphrophilus was analyzed by quantitative PCR and cultivation (the 58 samples collected at the last day of field study). The collected Aa strains were characterized and leukotoxin promoter typed. Additionally, herbal plants commonly used for oral hygiene were assessed for the inhibition of leukotoxicity. Results and Conclusions: The prevalence of Aa in stimulated whole saliva was high (71.8%), with the JP2 genotype detected in one individual, and A. aphrophilus in 99% of the sampled individuals. The commonly used herbal plant, Warburgia ugandensis, inactivated Aa leukotoxicity. The Aa virulence might be reduced through use of W. ugandensis and the high levels of A. aphrophilus.

Low bone mineral density is associated with severe periodontitis at the end of the second decade of life: A population-based study.

To evaluate the association between low bone mineral density (BMD) and severe periodontitis at the end of the second decade of life. This population-based study analysed 2032 youngers (18-19 years old) of the RPS cohort. BMD of lumbar spine (BMD-LS) and of the whole body (BMD-WB) were assessed by dual x-ray emission densitometry. Low BMD-LS (Z-score ≤ -2) and low BMD-WB (Z-score ≤ -1.5) were correlated with severe periodontitis. The extent of periodontal disease was also evaluated as the following outcomes: proportions of teeth affected by clinical attachment loss ≥5 mm and probing depth ≥5 mm. Multivariate models by sex, education, family income, risk of alcohol dependence, smoking, plaque, bleeding index, and body mass index were estimated through logistic regression (binary outcomes) and Poisson regression (continuous outcomes). The prevalence of severe periodontitis was 10.97%. Low BMD-LS (odds ratio [OR]=2.08, confidence interval [CI] = 1.12-3.85, p= .01) and low BMD-WB (OR=1.34, CI=1.001-1.81, p= .04) were associated with severe periodontitis in the final multivariate models. Low BMD-LS and BMD-WB were also associated with a greater extent of periodontitis (p< .05). Low BMD was found to be associated with the severity and extent of periodontitis in adolescents. Adolescents at peak bone mass age presenting low BMD are more likely to be affected by severe periodontitis.

Systemic circulating inflammatory burden and periodontitis in adolescents.

To analyze the association between systemic inflammatory burden of cardiovascular disease (CVD) risk and periodontitis in adolescents, including mediating pathways triggered by their common risk factors. Using a population-based sample study (n = 405) of Brazilian adolescents (17-18 years old), direct and mediation pathways triggered by "Socioeconomic Status," "Adiposity," Smoking, and "Blood Pressure" were modelled for the association between the "Systemic Circulating Inflammatory Burden of CVD Risk" (IL-1β, IL-6, IL-8, TNF-α) and the "Initial Periodontitis" (bleeding on probing (BoP), probing depth (PD) ≥ 4 mm, clinical attachment loss (CAL) ≥ 4 mm), both as continuous latent variables, using structural equation modeling. Sensitivity analysis was performed for the outcomes "Gingivitis" (visible plaque; BoP); "Moderate Periodontitis" (PD ≥ 5 mm and CAL ≥ 5 mm) and periodontitis (CDC-AAP case definition). Higher "Systemic Circulating Inflammatory Burden of CVD Risk" was directly associated with higher "Initial Periodontitis" (standardized coefficient [SC] = 0.178, P value < 0.001). Lower "Socioeconomic Status" (SC = - 0.022, P value = 0.015) and Smoking (SC = 0.030, P value = 0.021) triggered the "Initial Periodontitis", mediated by "Systemic Circulating Inflammatory Burden of CVD Risk". Sensitivity analysis showed a dose-response relationship between "Systemic Circulating Inflammatory Burden of CVD Risk" and "Moderate Periodontitis" (SC = 0.323, P value = 0.021). "Systemic Circulating Inflammatory Burden of CVD Risk" appeared as an underlying mechanism of early periodontal breakdown in adolescents, also triggered by social vulnerability and smoking. The association between periodontitis and CVD in adulthood seems to establish much earlier in life than had been previously studied, giving impetus to preventive approaches focused on their common risk factors.

Prevalence of Aggregatibacter actinomycetemcomitans and Periodontal Findings among 14 to 15-Year Old Danish Adolescents: A Descriptive Cross-Sectional Study.

Aggregatibacter actinomycetemcomitans (Aa) is a keystone pathogen associated with periodontitis in adolescents. The knowledge on the prevalence of Aa and periodontitis among adolescents in Northern Europe is sparse. A total of 525 14- to 15-year-old adolescents from the municipality of Aarhus, Denmark, underwent a full-mouth clinical examination. Plaque score (PS), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL) were recorded. Subgingival plaque samples (SPS) and stimulated saliva samples (SSS) were collected and analyzed for the presence of JP2 and non-JP2 genotypes of Aa using real-time PCR. A total of 70 (13.3%) individuals were positive for Aa, with 17 found in SPS, 19 in SSS, and 35 in both. The highly leukotoxic JP2 genotype of Aa was not detected. The individuals positive for Aa in both SPS and SSS had poorer periodontal outcomes (PPD and CAL) than individuals without Aa and individuals carrying Aa in either SPS or SSS only. In conclusion, 13% of 14- to 15-year-old Danish adolescents were positive for Aa, and the presence of Aa in both SPS and SSS was associated with poorer periodontal outcomes.

Active Matrix Metalloproteinase-8 Point-of-Care (PoC)/Chairside Mouthrinse Test vs. Bleeding on Probing in Diagnosing Subclinical Periodontitis in Adolescents.

This cross-sectional study compares the effectiveness of an active MMP-8 (aMMP-8) point-of-care (PoC)/chairside mouthrinse test to the conventional bleeding on probing (BOP) (cutoff 20%) test in detecting subclinical periodontitis/pre-periodontitis in Finnish adolescents. The study was carried out at the Kotka Health Center, Finland. A total of 47 adolescents (30 boys/17 girls) aged 15–17 were first tested with the aMMP-8 PoC test, followed by a full-mouth evaluation of clinical parameters of oral health including periodontal, oral mucosal, and caries assessment. A periodontist performed these clinical examinations. The aMMP-8 PoC test result had much stronger association with subclinical periodontitis than the BOP 20% test (2.8–5.3 times stronger in terms of odds ratio). The aMMP-8 PoC test had ≥2 times higher sensitivity than the BOP 20% test with, generally, the same specificity. Further, the aMMP-8 PoC test had generally better accuracy and lower false negative percentages. The aMMP-8 PoC test seemed to be more effective than the conventional BOP test in detecting subclinical periodontitis/pre-periodontitis in adolescents reducing the risk of their undertreatment. However, the sample size may be a limiting factor, and more studies are needed to confirm our results for both adolescents and adults.

Pattern recognition receptor polymorphisms in early periodontitis.

Even though bacteria trigger inflammation, most of the tissue destruction in periodontitis is due to the host inflammatory response. In addition to immunological events that drive development of early periodontitis, numerous environmental factors like genetics and smoking play a role. We investigated whether the carriage of selected single nucleotide polymorphisms (SNP) of toll-like receptors (TLR), NOD-like receptors (NLR) and RIG-I-like receptors (RLR) was associated with the diagnosis of early periodontitis in a case-control study. Adolescents with positive (n=87) and negative (n=73) diagnosis for periodontitis had blood samples taken. All participants were genotyped for 42 SNP in the genes encoding TLR1-10, NOD1-2, DDX58, and IFIH1 using multiplex assays. Associations between SNP and periodontitis diagnosis were tested. TLR1-rs5743611 showed protective effect for periodontitis (CC versus GG and GC, P=0.01, odds ratio [OR] 0.10, 95% confidence interval [CI] 0.01-0.78). Carriage of the TLR4-rs7873784 was associated with higher odds for periodontitis (GG versus CC and GC, P=0.05, OR 2.30, 95% CI 1.00-5.63; GG versus GC, P=0.05, OR 2.46, 95% CI 1.01-5.99). In male participants, reduced susceptibility to periodontitis was observed in carriers of TLR7-rs3853839 (CC versus GG and CG, P=0.02, OR 0.30, 95% CI 0.11-0.85) and TLR8-rs3764879 (CC versus GG and CG, P=0.02, OR 0.31, 95% CI 0.12-0.82). Associations were maintained after adjustments for sex, smoking habits, and mother´s education. This study demonstrated an association between TLR1-rs5743611, TLR4-rs7873784, TLR7-rs3853839, and TLR8-rs3764879 and susceptibility to periodontitis in adolescents.

Cross-sectional analysis of risk factors for subclinical periodontitis; active matrix metalloproteinase-8 as a potential indicator in initial periodontitis in adolescents.

The aim of this study was to investigate how different patient-related risk indicators might be associated with the odds of developing subclinical periodontitis in adolescents. This cross-sectional study included 252 Finnish individuals aged 15 to 16 years, of whom 141 were boys and 111 girls. A specially trained dentist performed clinical examinations: measurements included periodontal indexes (bleeding on probing, visible plaque index, root calculus, and probing depth, smoking by pack-years, periodontal bacteria (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola) and the potential salivary periodontal biomarkers (active matrix metalloproteinase-8 [aMMP-8], polymorphonuclear leukocyte elastase [PMN elastase], and total protein, albumin, immunoglobulin A, immunoglobulin G, and immunoglobulin M). Results were analyzed by ordinal logistic regression, one-way analysis of variance, Fisher exact test, and Kruskal-Wallis H test. The main finding of this study was that subclinical periodontitis in adolescents was statistically significantly associated with elevated salivary aMMP-8 but not with PMN elastase. Also, adolescents with subclinical periodontitis had statistically significantly higher levels of bleeding on probing, root calculus, and dental plaque than adolescents without subclinical periodontitis. We suggest that the main risk factor for subclinical periodontitis in adolescents is the partly calcified, dysbiotic bacterial biofilm, which interacts with the immune defenses of the host; this leads to gingival inflammation and eventually to deepening periodontal pockets. This proinflammatory subclinical periodontitis stage, which represents stage I periodontitis in the new classification, is reflected as elevated salivary aMMP-8 levels in oral fluids.

Generation of a recombinant Aggregatibacter actinomycetemcomitans RTX toxin in Escherichia coli

A leukotoxin (LtxA) that is produced by Aggregatibacter actinomycetemcomitans (Aa) is an important virulence determinant in an aggressive form of periodontitis in adolescents. Understanding the function of this protein at the molecular level is critical to elucidating its role in the disease process. To accomplish genetic analysis of the protein structure and relating these observations to toxin function, we have developed an E. coli expression system for the generation and rapid purification of LtxA. Cloning the structural toxin gene, ltxA, from Aa strain JP2 under control of T7 promoter-1 of pCDFDuet-1 vector resulted in expression of a 114 KDa protein which could be easily purified by the presence of a carboxy-terminal engineered double hexahistidine (double–His6) tag and was immunologically reactive with an anti-LtxA monoclonal antibody, but was not cytotoxic. Cloning a second gene, ltxC, an acyltransferase gene, into the vector under control of T7 promoter-2, resulted in expression of the biologically active LtxA. The toxin was extracted from E. coli inclusion bodies, purified by immobilized metal affinity chromatography, and refolded by dialysis. When compared by circular dichroism (CD) spectroscopy analysis, acylated recombinant LtxA has a secondary structure consistent with wt LtxA, while variations in α-helical structure of nonacylated LtxA were observed. No modifications in α-helix were found upon the toxin's binding with liposome-incorporated cholesterol. Our results suggest that pure, biologically active recombinant LtxA can be isolated by a one-step affinity chromatography from E. coli. The toxic and structural properties of the recombinant LtxA are similar to its wt counterpart.

Soluble urokinase-type plasminogen activator receptor is associated with signs of periodontitis in adolescents.

Owing to its molecular stability in body fluids, soluble urokinase-type plasminogen activator receptor (suPAR) is used as a biomarker for the level of systemic inflammation. This study compares the suPAR levels in serum with those in the saliva of adolescents and evaluates their association with the periodontal conditions. Adolescents identified as screen positive (n = 87) or screen negative (n = 73) for periodontitis had saliva and serum samples taken, along with subgingival plaque samples. The concentrations of suPAR were determined in saliva and serum, and 18 microbial species and the immunoglobulin response to them was evaluated. Factor analyses were used to reduce the number of variables within each of the domains of clinical, microbiological, and immunological findings. The median salivary suPAR concentration was 13.18 [(interquartile range (IQR): 6.20-23.36] μg l-1 and was not associated with the serum suPAR levels (median 2.05; IQR: 1.62-2.46 μg l-1 ). Linear regression analysis showed that the log10 (salivary suPAR concentration) was statistically significantly positively associated with the clinical phenotype 'Periodontitis Extent' (β = 0.28; 95% CI: 0.16-0.39) along with 'Putative periodontopathogens' (β = 0.65; 95% CI: 0.51-0.79). The study represents the first determination of salivary suPAR concentration in a larger well-defined adolescent population. Our results suggest the potential for clinical use of suPAR in saliva as an inflammatory risk indicator/biomarker of periodontitis.

Is overweight/obesity a risk factor for periodontitis in young adults and adolescents?: a systematic review.

Obesity in young adults and adolescents is associated with chronic co-morbidities. This project investigated whether being overweight or obese is a risk factor for periodontitis in adolescents (13-17years) and young adults (18-34years). A search of 12 databases was conducted using Medical Subject Headings/Index and Emtree terms. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, articles published between 2003 and 2016 were screened that reported periodontal and anthropometric measures. The Newcastle-Ottawa Scale was used to appraise the quality of studies. Of 25 eligible studies from 12 countries, 17 showed an association between obesity and periodontitis (odds ratios ranged from 1.1 to 4.5). The obesity indicators of body mass index, waist circumference, waist-hip ratio and body fat percentage were significantly associated with measures of periodontitis of bleeding on probing, plaque index, probing depths, clinical attachment loss, calculus, oral hygiene index and community periodontal index. Two prospective cohort studies in the review showed no significant association between obesity and periodontitis, but these studies had limitations of study design and used inappropriate epidemiological diagnostic measures of periodontitis. There was evidence to suggest that obesity is associated with periodontitis in adolescents and young adults. Systematic Review Registration: PROSPERO Registration Number: CRD42016046507.

Concentrated growth factor for the treatment of intrabony defects in chronic periodontitis in adolescents

Searchable abstracts of presentations at key conferences on calcified tissues ISSN 2052-1219 (online)

Inflammatory mediator polymorphisms associate with initial periodontitis in adolescents.

Several studies have addressed cytokine gene polymorphisms and their possible associations with periodontitis. We examined the association between salivary anti‐ and pro‐inflammatory mediator polymorphisms and initial periodontitis in Finnish adolescents, taking into account the effect of smoking. Salivary samples of 93 clinically examined adolescents from Eastern Finland were analyzed. Their oral health and smoking habits were recorded. Periodontal probing depth (PPD), and bleeding on probing (BOP) at four sites per tooth, root calculus (RC), and visible plaque index (VPI) were recorded from the index teeth. Salivary MMP‐8 median values were assessed. The sites with ≥4 mm PD were categorized as follows: PPD1 = one or more ≥4 mm pocket, PPD2 = two or more ≥4 mm pockets, and PPD3 = three or more ≥4 mm pockets. Genomic DNA was extracted from 300 μl of the saliva samples by genomic QIAamp® DNA Blood Mini Kit and genotyped for polymorphisms. Genetic variants for genotyping were selected from the following genes of interest: S100A8, FCGR2A, FCGR2B, IL10, MMP8, MMP3, MMP13, VDR, TLR4, MMP2, MPO, ELANE, IL1A, IL1B, IL1RN, CD28, MMP9, DDX39B, NFKBIL1, LTA, TNF, SOD2, IL6, TLR4, TIMP1, and SYN1. After false discovery rate control (FDR), polymorphisms in MMP3 (rs679620, rs520540, rs639752), CD28 (rs3116496), and VDR (rs2228570) associated (FDR q < 0.05) with deepened periodontal pockets. Smoking did not affect the results. Genetic polymorphisms of pro‐inflammatory mediators MMP3, CD28, and VDR seem to link to initial periodontitis.