Plaque In Children Research Articles

Карієсогенна мікрофлора зубного нальоту у дітей, хворих на бронхіальну астму

Карієсогенна мікрофлора зубного нальоту у дітей, хворих на бронхіальну астму

A dermoscopic clue for alopecic plaques in children

An 8-year-old boy was brought by his parents for consultation regarding asymptomatic alopecic patches that had appeared 1 year earlier. The patient was a native of a rural area in Morocco and had recently moved to Spain. He had been treated with topical steroids because of a suspicion of alopecia areata, with no response. The clinical examination revealed multiple, diffuse plaques of alopecia in the parieto-occipital region without scaling, redness, or any other sign of inflammation (Fig 1). A hair pull test was positive.

Effect of maternal use of chewing gums containing xylitol on transmission of mutans streptococci in children: a meta-analysis of randomized controlled trials.

Mutans streptococci (MS) are the major causative bacteria involved in human dental decay. Habitual consumption of xylitol has been proved to reduce MS levels in saliva and plaque. To evaluate the effect of the maternal use of xylitol gum on MS reduction in infants. A structured literature review and meta-analysis. A random effects model was used to assess the relative risks of the incidence of MS in the saliva or plaque of children who were 6, 9, 12, 18, and 24 months old. We reviewed 11 RCTs derived from 5 research teams that included 601 mothers. Our results indicated that the incidence of MS in the saliva or plaque of the infants was significantly reduced in the xylitol group (risk ratio: 0.54; 95% confidence interval: 0.39-0.73, at 12-18 months) and (risk ratio: 0.56; 95% confidence interval: 0.40-0.79, at 36 months) compared with the control groups. The long-term effect of maternal xylitol gum exposure on their children's dental caries was controversial. Habitual xylitol consumption by mothers with high MS levels was associated with a significant reduction in the mother-child transmission of salivary MS.

How effective is a chewable brush in removing plaque in children? A pilot study

The aim of this pilot study was to evaluate the plaque removal efficiency of a chewable toothbrush (CB) in children. A total of 20 patients aged 10-12 years who attended to the Department of Pediatric Dentistry were enrolled in the study. This was a single-blinded crossover study which examined plaque removal efficiency of a CB compared to a manual toothbrush (MB) following a consecutive use. After professional prophylaxis had been given, participants refrained from brushing and chewing for 48 h. Supragingival plaque was examined using the Turesky modification of the Quigley-Hein Index (TQHI) and the simplified oral hygiene index (OHI-S). For statistical comparison, the difference (prebrushing minus postbrushing) in average scores was calculated. Data were evaluated by Mann-Whitney U-test, with a P 0.05). Within the limits of this study, the experimental chewable brush was found to be as effective as a manual brush in removing plaque. The chewable brush may be an appropriate oral hygiene adjunct for school children, including children with disabilities.

English

Helicobacter pylori is a spiral gram negative bacterium that normally grows in the stomach, and is the main causal agent of gastritis and peptic ulcers. In 1994, The International Agency for Research on Cancer recognized H. pylori as a carcinogenic factor for stomach cancer. The oral cavity has been proposed as a reservoir for H. pylori and several authors have demonstrated the presence in adult patients of the organism in saliva and dental plaque. However, isolation of H. pylori in children is still questionable. Several investigators have reported the presence of H. pylori in the dental plaque of children, sometimes associated with gastro-esophageal reflux. These isolations has been realized by polymerase chain reaction were gold standard is the culture. On the other hand, many authors have failed to isolate H. pylori by culture in samples obtained from the saliva or dental plaque. We performed an extensive review of the literature to facilitate future research in this controversial topic. Key words: Helicobacter pylori, children, dental plaque, polymerase chain reaction, urease breathe test.

PH and bacterial profile of dental plaque in children and adults of a low caries population

ObjectiveThis study compares pH and microbiological profile of dental plaque in children and adults of a low caries population. Material and methodsThirty-nine children, 12–14 years of age and 45 adults between 20 and 39 years of age in 5 Karen villages of the Tak province, Northern Thailand were examined for plaque, calculus, caries (DMFT) and pH measurements in resting plaque and after a sucrose rinse. Information on dietary and oral hygiene habits was obtained through interviews using a fixed questionnaire. Microbiological profile of plaque samples was analyzed with DNA–DNA checkerboard technique. ResultsMean DMFT was 0.77 ± 1.56 and 87% of the adults and 67% of the children were caries free (p < 0.05). The mean resting pH was for both age groups in the range of 7.0–7.1 and significantly higher than a Swedish caries free reference group. Karen adult men had significantly lower pH minimum than females and children (p < 0.05). Supragingival plaque samples showed high levels of low acidogenic and anaerobic species, which dominated over strong acid producers such as streptococci. ConclusionThe study indicates that the Karen children and adults has a plaque physiology and microbiology predominating by low acidogenic anaerobes, which in addition to the low sucrose intake explains the low caries prevalence in this population.

Plaque Bacterial Microbiome Diversity in Children Younger than 30 Months with or without Caries Prior to Eruption of Second Primary Molars

ObjectiveOur primary objective is to phylogenetically characterize the supragingival plaque bacterial microbiome of children prior to eruption of second primary molars by pyrosequencing method for studying etiology of early childhood caries.MethodsSupragingival plaque samples were collected from 10 caries children and 9 caries-free children. Plaque DNA was extracted, used to generate DNA amplicons of the V1–V3 hypervariable region of the bacterial 16S rRNA gene, and subjected to 454-pyrosequencing.ResultsOn average, over 22,000 sequences per sample were generated. High bacterial diversity was noted in the plaque of children with caries [170 operational taxonomical units (OTU) at 3% divergence] and caries-free children (201 OTU at 3% divergence) with no significant difference. A total of 8 phyla, 15 classes, 21 orders, 30 families, 41 genera and 99 species were represented. In addition, five predominant phyla (Firmicute, Fusobacteria, Proteobacteria, Bacteroidetes and Actinobacteria) and seven genera (Leptotrichia, Streptococcus, Actinomyces, Prevotella, Porphyromonas, Neisseria, and Veillonella) constituted a majority of contents of the total microbiota, independent of the presence or absence of caries. Principal Component Analysis (PCA) presented that caries-related genera included Streptococcus and Veillonella; while Leptotrichia, Selenomonas, Fusobacterium, Capnocytophaga and Porphyromonas were more related to the caries-free samples. Neisseria and Prevotella presented approximately in between. In both groups, the degree of shared organism lineages (as defined by species-level OTUs) among individual supragingival plaque microbiomes was minimal.ConclusionOur study represented for the first time using pyrosequencing to elucidate and monitor supragingival plaque bacterial diversity at such young age with second primary molar unerrupted. Distinctions were revealed between caries and caries-free microbiomes in terms of microbial community structure. We observed differences in abundance for several microbial groups between the caries and caries-free host populations, which were consistent with the ecological plaque hypothesis. Our approach and findings could be extended to correlating microbiomic changes after occlusion establishment and caries treatment.

Lymphoplasmacytic plaque in children: a report of two new cases with review of the literature

Lymphoplasmacytic plaque in children has been proposed as a rare, emerging clinicopathologic entity characterized by solitary, extratruncal, asymptomatic papules and plaques that are typically found in healthy young Caucasian females. Biopsy of these lesions reveals a dermal lymphoplasmacytic infiltrate with or without epithelioid granulomas. Two unique patients with lymphoplasmacytic plaque in children are presented in this report, including a 26-month-old female with a lesion on her finger, who represents both the youngest described patient and the first documented with a finger lesion, as well as a 17-year-old young woman with a left thigh lesion, who represents the patient with the longest clinically and histopathologically observed lesion to date. These two additional patients corroborate the experience of lymphoplasmacytic plaque in children in the six previously reported cases and further expand the clinicopathologic spectrum of the disease. Recognition of lymphoplasmacytic plaque in children is important to facilitate distinction from potential differential considerations, including lymphoproliferative disorders and infectious conditions, particularly as the experience to date appears to suggest that lymphoplasmacytic plaque in children represent a reactive (pseudolymphomatous) condition.

A Pretibial Plaque in a Five and a Half year–Old Girl

A five and a half year-old girl presented with a reddish-brown plaque on her right anterior tibia, first observed 1 year previously and without any history of injury or insect bite. Histological examination showed a dense dermal infiltrate composed of plasma cells and small lymphocytes, combined with lymphocytic exocytosis in the epidermis and interface dermatitis. In addition, a second biopsy found small epithelioid granulomas within the lymphoplasmocytic infiltrate. Infection was ruled out. No clonality was found. None of the treatments attempted was successful (antibiotics and steroids), and the lesion was stable but did not improve for 4 years. The same features typical of lymphoplasmocytic pseudolymphoma were observed on a third biopsy. A diagnosis of "pretibial lymphoplasmocytic plaque" was made on the basis of clinical and histological findings. Recently, 3 other cases of this type of lymphocytic and plasma cell cutaneous infiltrate with very distinctive clinical and histopathological features have been reported in children. Our case is instructive because it presents new and as yet undocumented histopathologic features including a lichenoid reaction with vacuolization of the basal cell layer and numerous apoptotic bodies, apparent in 2 of the 3 biopsies, and hypervascularity with thick-walled blood vessels lined with plump endothelial cells in the upper dermis. The clinicopathological presentation of these cases, including ours, is homogenous suggesting a specific entity described as "pretibial lymphoplasmocytic plaque in children". This seems to be a benign, chronic, reactive process, probably arising secondary to a local response to an unknown antigen.

Short Communication: Polymicrobial community in teeth associated with severe early-childhood caries

This was to characterise the microbial diversity in the complex dental plaque of children with severe early-childhood caries (S-ECC), using the denaturing gel gradient electrophoresis (DGGE) technique. The DGGE technique was used as a diagnostic tool to analyse samples from the oral cavity of a patient with S-ECC. Dental plaque samples from a 3-year-old child with S-ECC were taken from the primary central maxillary incisor (biofilm on vestibular surface), primary maxillary molar (biofilm on vestibular surface), primary central maxillary incisor (dentine), primary maxillary molar (dentine) and saliva and then analysed by PCR-DGGE. Three bands occurred in all samples, moreover, 86% of similarity was observed in the pattern of bands between incisor and molar teeth biofilm samples, including four similar bands. DGGE is a valuable tool for differentiating the microbial composition of the oral plaque in S-ECC children.

Papillary stones with Randall's plaques in children: clinicobiological features and outcome

Papillary stones with Randall's plaques in children: clinicobiological features and outcome

Metal-ion susceptibility of oral bacterial species

This study aimed to evaluate the effect of lead (Pb) on growth of bacterial species related to dental diseases in vitro. The effects of lead acetate on representative species of the oral flora were examined at 0.1-10 mmol l(-1) and compared with the effect of silver nitrate and ferrous sulfate. The minimal inhibitory concentration of lead acetate was between 0.15 and 5 mmol l(-1) for the bacterial strains tested. The minimal bactericidal concentration of lead acetate for most oral species was detected in the range of 5-10 mmol l(-1). Silver nitrate at a concentration of 1.25 mmol l(-1) was sufficient to exhibit antibacterial activity against almost all bacteria tested. Ferrous sulfate had the lowest effect. The study indicated a general antimicrobial effect of lead on oral bacterial species in the range of 0.15-10 mmol l(-1). The toxicity of silver nitrate was the highest, whereas that of ferrous sulfate was the lowest. Gram-positive species had a tendency to be less susceptible for metals than Gram-negatives. The study shows that it is possible that microbiological changes may occur in the dental plaque in children because of toxic exposure of environmental lead.

A study of influence of sugars on the modulations of dental plaque pH in children with rampant caries, moderate caries and no caries

The present study is undertaken to find out the pH of resting plaque in children with no caries, moderate caries and rampant caries and to determine the modulations of plaque pH with different sugar solution rinses viz: sucrose, glucose and fructose. The study was carried out on forty five children, in the age group of 3-10 years (25 males and 20 females). The child was given 10 ml of test solution and was asked to rinse and swish it in the mouth for a period of 30 sec. Plaque samples were taken from 20 different spots after 5, 10, 20 and 30 min of the rinse and pH values of all the samples were determined. Results show that there was a statistically significant (P<0.05) difference between the pH values of plaque at different intervals of time with sucrose, fructose and glucose solution rinse in children with moderate caries, rampant caries as compared to the caries free group. Sucrose was found to be highly cariogenic in all the children with a greater potentiating effect in moderate and rampant caries. Glucose also appeared to have a cariogenic role while fructose had the least of it all.

Pretibial Lymphoplasmacytic Plaque in Children

Pretibial Lymphoplasmacytic Plaque in Children

The Relationship of Prevotella intermedia, Prevotella nigrescensand Prevotella melaninogenica in the Supragingival Plaque of Children, Caries and Oral Malodor

A relationship between the distribution of periodontal bacteria species and malodor in children has not been sufficiently investigated. The present study was undertaken to determine the presence of 3 periodontopathic bacteria (Prevotella spp. P. intermedia, P. nigrescens, P. melaninogenica) in the supragingival plaques of 3 to 16-year-old children with different oral health conditions and oral malodor. The number of decayed and filled primary teeth (df) and Decayed, Missing and Filled permanent teeth (DMF), Papillary Marginal and Attached gingivitis (PMA) index, Oral Hygiene Index (OHI), and oral malodor of each subject were determined prior to the collection of supragingival plaques. Three periodontopathic bacteria (P. intermedia, P. nigrescens, P. melaninogenica) in supragingival plaques were detected by using an immunoslot blot assay with monoclonal antibodies specific for each microorganism. The frequencies of periodontopathic bacteria in children with and without caries were not significantly different from each other. Positivity for P. intermedia, but not for P. nigrescens or P. melaninogenica was correlated with oral malodor. Oral malodor was also correlated with the debris index, a component of OHI. The group with the higher OHI showed a higher prevalence of periodontopathic bacteria. For the 3 periodontopathic bacteria in the subjects tested, plaques positive for any of them were not age related. However the frequencies of all 3 periodontopathic bacteria were the highest in the 3-6-year olds. The supragingival plaques in children can harbor 3 species of periodontopathic bacteria, P. intermedia, P. nigrescens, and P. melaninogenica.

The effect of traditional African food mixtures on growth, pH and extracellular polysaccharide production by mutans streptococci in vitro

Four, traditional African food mixtures (maize plus milk and sugar, maize plus gravy, samp plus beans, brown bread plus margarine and peanut butter) were evaluated for their ability to sustain the growth of mutans streptococci in batch culture. A synthetic complex medium, brain heart infusion with 3% sucrose was used as an experimental control. Six NCTC laboratory reference strains and five clinical isolates collected from the plaque of children were investigated. The doubling time of bacterial strains was prolonged in maize plus gravy (2.5–6.0 h) and samp plus beans (1.3–9.9 h), and the number of cell divisions was low, compared with bread plus margarine plus peanut butter (0.7–5.1 h). The least amount of acid was produced in maize plus milk plus sugar (3.92±8.15 mmole/mL), and the average pH during the fermentation of maize plus milk plus sugar, maize plus gravy and samp plus beans did not drop below the critical point for enamel demineralisation, pH 5.7. Bacterial growth in samp plus beans produced a small quantity of lactic acid (0.46±1.10 mmole/mL) compared to bread plus margarine and peanut butter (2.64±3.30 mmole/mL) and BHI plus 3% sucrose (12.23±10.72 mmole/mL). Extracellular polysaccharide (ECP) produced was lowest in maize plus milk and sugar (0.22±0.33 mg/mL), compared with the remaining food mixtures (0.47–1.75 mg/mL). Statistical analysis showed that the influence of the mixed-foods on doubling time ( F = 3.0 1 , P = 0.0 3 ), pH ( F = 1 4.4 1 , P < 0.0 0 0 1 ) and ECP ( F = 1 3 5.3 2 , P < 0.0 0 0 1 ) was greater than the significant variance found between mutans streptococci strains. Results suggest that the level of mutans streptococci activity in samp plus beans, maize plus milk and sugar and maize plus gravy contributes little towards the formation of dental caries, and that significant differences exist between mutans streptococci laboratory reference and clinical strains in response to traditional African food mixtures.

Correlation study of plaque and gingival indexes of mothers and their children

This study aimed to compare the periodontal condition between plaque and gingival indexes in 30 pairs of mother and child with mixed dentition, as well as to correlate the findings with some of their social and oral hygiene habits. Mother's and child's plaque and gingival indexes were recorded during clinical examination. Periapical and bitewing radiographs were taken in order to assess the presence of any pathologic bone loss. Questionnaires answered by the mothers were used to collect information regarding the mother's and the child's habits of tooth hygiene and the mother's job, instruction level and family income. The data collected from the mothers' group and from the children's group were statistically analyzed both separately and with the two groups together. From the statistical analyses (Pearson correlation test, student test and Covariance analysis), it was possible to conclude that there was a greater correlation between the plaque and gingival indexes in the mothers' group than in the children's group. No significant correlation between plaque and gingival indexes could be found between the pairs. Also, bone loss and plaque and gingival indexes in the children did not show any correlation. The mothers' plaque indexes increased with age and decreased when they flossed everyday and when they had a job. The children's plaque indexes were lower when they had their tooth hygiene done by their mothers, when the latter had declared that they flossed their children's teeth everyday, and also when the mothers had a job. Children's gingival indexes increased with age and decreased when they brushed their teeth more often, when their mothers had a job and when their mothers declared they are used to flossing every day.

Genotypic diversity of oralActinomyces naeslundiigenospecies 1 and 2 in caries-active preschool children

A total of 991 isolates of Actinomyces naeslundii were obtained from sound approximal tooth sites in either caries-active (n = 35) or caries-free (n = 20) preschool children. From this group of isolates, 101 strains were chosen to study the genotypic diversity of A. naeslundii genospecies 1 (n = 30), catalase-positive (n = 30), and catalase-negative genospecies 2 (n = 41). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), with a pair of primers targeting the 16S ribosome RNA gene (16S rDNA), and MnlI digestion together with randomly amplified polymorphic DNA (RAPD) with eight arbitrary, single 10-mer primers were performed to generate genetic profiles of selected Actinomyces isolates. The hierarchic relationships of genetic profiles were finally analyzed using computerized dendrograms. There was no significant difference in the prevalence rates and proportions of either genospecies 1 or 2 between the caries-free and caries-active groups, although a higher prevalence of genospecies 2 was noted in the total population. Dendrogram analyses of the 16S rDNA PCR-RFLP profiles revealed that all strains belonging to A. naeslundii genospecies 1 could be subgrouped into three genotypes (T7, T18, and T19), with a single predominant genotype, T18 (27/30). Catalase-positive strains for genospecies 2 fell into three subtypes (T4, T7, and T17), whereas the catalase-negative counterparts were distributed amongst 16 subtypes. No specific genotype was significantly associated with caries activity. We conclude that heterogeneous subgroups of A. naeslundii genospecies 1 and 2, particularly the latter, are the constituent flora of dental plaque in children and may contribute to the pathogenesis of childhood caries.

The microbiota of young children from tooth and tongue samples.

This study determined the frequency with which 38 microbial species were detected in 171 randomly selected children from 6 to 36 months of age. Children were sampled and dental caries measured. Oral samples were assayed by means of a checkerboard DNA probe assay. The detection frequencies from tongue samples in children under 18 mos were: S. mutans 70%, S. sobrinus 72%, P. gingivalis 23%, B. forsythus 11%, and A. actinomycetemcomitans 30%, with similar detection frequencies in children over 18 mos. Thus, S. mutans and the periodontal pathogens, P. gingivalis and B. forsythus, were detected even in the youngest subjects. Species associated with caries included S. mutans (children ages 18-36 mos) and A. israelii (children ages < 18 mos), the latter species possibly reflecting increased plaque in children with caries. Species detection from tooth and tongue samples was highly associated, with most species detected more frequently from tongue than from tooth samples in children under 18 mos, suggesting that the tongue was a potential microbial reservoir.

Genetic and physiologic characterization of urease of Actinomyces naeslundii.

Ammonia production from urea by ureolytic oral bacteria is believed to have a significant impact on oral health and the ecological balance of oral microbial populations. In this study we cloned and characterized the urease gene cluster of Actinomyces naeslundii, which is one of the pioneer organisms in the oral cavity and a significant constituent of supragingival and subgingival dental plaque in children and adults. An internal fragment of the ureC gene of A. naeslundii WVU45 was initially amplified by PCR with degenerate primers derived from conserved amino acid sequences of the large catalytic subunit of urease in bacteria and plants. The PCR product was then used as a probe to identify recombinant bacteriophages carrying the A. naeslundii urease gene cluster and roughly 30 kbp of flanking DNA. Nucleotide sequence analysis demonstrated that the gene cluster was comprised of seven contiguously arranged open reading frames with significant homologies at the protein and nucleotide sequence levels to the ureABCEFGD genes from other organisms. By using primer extension, a putative transcription initiation site was mapped at 66 bases 5' to the start codon of ureA. A urease-deficient strain was constructed by insertion of a kanamycin resistance determinant within the ureC gene via allelic replacement. In contrast to the wild-type organism, the isogenic mutant was unable to grow in a semidefined medium supplemented with urea as the nitrogen source and was not protected by the addition of urea against killing in moderately acidic environments. These data indicated that urea can be effectively utilized as a nitrogen source by A. naeslundii via a urease-dependent pathway and that ureolysis can protect A. naeslundii against environmental acidification at physiologically relevant pH values. Therefore, urease could confer to A. naeslundii critical selective advantages over nonureolytic organisms in dental plaque, constituting an important determinant of plaque ecology.