The oral health environment and the equal environment assumption (EEA) among 1-8-year-old twins.

AIM: The purpose of the present study was to describe the oral health environment in preschool children and to examine the extent to which paired twins experience the same oral health environment. MATERIALS AND METHODS: In collaboration with The Medical Birth Registry of Norway (MBRN) 100 twin families who participated in the Norwegian Mother and Child Cohort, were invited to take part in ongoing studies on oral health. Participating twin families lived in Oslo and the surrounding counties of the capital. The age range of the participating twins was 1-8 years. A clinical examination took place at The Institute of Clinical Dentistry, University of Oslo in 2008. The oral health environment was measured in two ways: 1) Interview. Mothers were interviewed by trained interviewers about oral health related habits of each of the twins. 2) Weekend diet log. Parents listed 84 different deserts, ice cream, sweets, cakes, cookies, fruits, snacks, and biscuits for each twin that were consumed on during the weekend. The statistical analyses comprised frequency distributions of the environmental variables and correlations between the variables within the pair of twins. RESULTS: The results showed a parental involvement in early tooth brushing and also an indication of tooth brushing not always being easy. Use of fluoride toothpaste started early, and two thirds of the children also used fluoride tablets. Use of pacifier was prevalent; the duration of use of pacifier and feeding bottle was relatively long. Nearly 75% of the parents indicated that they had no problems relatively to the twins' meals, and 53% mentioned that the twin pairs were different with regard to meals. Nearly 70% of the kindergartens had a clear health profile. The correlations varied between r = 0.45 and 1.00. CONCLUSION: The children in the present work were young, and the detailed information in this paper therefore adds to the knowledge of parental involvement in children's oral health. Generally the findings indicate a high level of involvement from the parents in the oral health environment at home. Altogether the results showed that the assumption of identical oral health environment cannot be supported by these data.

Juvenile idiopathic arthritis and rheumatoid arthritis: bacterial diversity in temporomandibular joint synovial fluid in comparison with immunological and clinical findings.

Temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA) occurs in up to 80% of affected children. The purpose of this study was to investigate the presence of bacterial DNA in synovial fluid, and to compare this with clinical and immunological findings in children with JIA, adults with persistent JIA, and adults with rheumatoid arthritis, in order to detect whether bacteria contribute to inflammation in TMJ arthritis. Synovial fluid and skin swab samples were collected from 30 patients (54 TMJs). Bacterial detection was performed using 16S rRNA pyrosequencing. Bacterial DNA was detected in 31 TMJs (57%) in 19 patients (63%). A positive statistically significant correlation was registered between bacterial DNA detected in TMJ synovial fluid and the following factors: total protein concentration in synovial fluid, interleukin 1ß, tumour necrosis factor alpha, adrenocorticotropic hormone, and adiponectin, as well as the duration of the general medical disease. Fourteen different bacterial species were detected in synovial fluid. Bacterial DNA in TMJ synovial fluid without contamination was detected in more than 50% of the patients. Studies are needed to evaluate the consequences of this bacterial DNA in synovial fluid with regard to TMJ arthritis.

Objective assessment of gastroesophageal reflux after short esophagomyotomy for achalasia with the use of manometry and pH monitoring.

The role of an antireflux procedure as an adjunct to esophagomyotomy for achalasia remains a subject of controversy. Little objective documentation exists of this operation's effect on sphincteric competence and the degree of postoperative gastroesophageal reflux. This report of esophageal manometry and 24-hour pH monitoring on 14 patients with esophageal achalasia whom we had previously treated by a short esophagomyotomy without an antireflux procedure provides such documentation. Esophagomyotomy reduced lower esophageal sphincter pressure by 12% to 71% (mean 41%) from a preoperative mean of 26.7 mm Hg to a postoperative mean of 14.6 mm Hg. The number of postoperative episodes of acid reflux per patient in 24 hours was fewer than 29 (normal < 49) in 13 patients, with a median of 12 episodes for the entire group. Esophageal acid exposure, measured as percentage of total time with pH less than 4.0 (normal < 4.5%), was below 4.5% in 10 patients, six of whom had values less than 1%. Among the four patients with values greater than 4.5%, only one had a temporal correlation of symptoms with an episode of acid reflux. Multivariate analysis showed that esophageal acid exposure time correlated only with the level of residual lower esophageal sphincter pressure during the relaxation phase of deglutition. A pressure less than 8 mm Hg was predictive of normal acid contact time (p < 0.001). Mean lower esophageal sphincter pressure, percent reduction in lower esophageal sphincter amplitude, postoperative vector volume, and length of the lower esophageal sphincter did not significantly correlate with amount of esophageal acid exposure. We conclude that a short esophagomyotomy without an antireflux procedure results in a competent lower esophageal sphincter in most patients. Increased esophageal acid exposure, when it occurs, is due to slow clearance of esophageal acid from relatively few reflux episodes and is more likely to occur when there is a high residual pressure during deglutition after myotomy. These findings suggest that the addition of an antireflux procedure to a short esophagomyotomy would not be expected to improve clinical results.

Subgingival plaque microbiota in HIV positive patients.

AIM: To describe and compare the predominant bacterial and fungal species associated with gingivitis, periodontitis, and linear gingival erythema (LGE), in HIV positive subjects with different immune status. METHODS: Viral loads and CD4 levels determined HIV disease status. From pooled subgingival plaque, 16S and 18S rDNA were cloned and sequenced to determine species identity. RESULTS: One hundred and nine bacterial species were identified from 14 subjects. Nearly half of the species were not cultivable. Notably, the classical putative periodontal pathogens, Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia were below the limit of detection and were not detected. Species of Gemella, Dialister, Streptococcus and Veillonella were predominant. In one HIV positive subject with periodontitis and low viral load, Gemella morbillorum, a known opportunistic pathogen, constituted 84% of the clones. Saccharomyces cerevisiae was the only fungal species detected in an LGE subject and in periodontitis subjects with high viral loads. In periodontitis patients with low viral loads, Candida albicans was predominant, while S. cerevisiae was only a minor component. CONCLUSION: These case studies suggest that other bacterial species, rather than the classical periodontal pathogens, may be involved in periodontal diseases of subjects with HIV. These data are indicative of opportunistic infections in a highly susceptible immunocompromised host.

Microbial risk indicators of early childhood caries.

The aim of this study was to use molecular identification methods, such as 16S RNA gene sequence and reverse-capture checkerboard hybridization, for identification of the bacteria associated with dental caries and with dental health in a subset of 204 twins aged 1.5 to 7 years old. A total of 448 plaque samples (118 collected from caries-free subjects and 330 from caries-active subjects) were used for analysis. We compared the bacteria found in biofilms of children exhibiting severe dental caries, with different degrees of lesion severity, with those found in biofilms of caries-free children. A panel of 82 bacterial species was selected, and a PCR-based reverse-capture checkerboard method was used for detection. A simple univariate test was used to determine the overabundance and underabundance of bacterial species in the diseased and in the healthy groups. Features identified with this univariate test were used to construct a probabilistic disease prediction model. Furthermore, a method for the analysis of global patterns of gene expression was performed to permit simultaneous analysis of the abundance of significant species by allowing cross-bacterial comparisons of abundance profiles between caries-active and caries-free subjects. Our results suggested that global patterns of microbial abundance in this population are very distinctive. The top bacterial species found to be overabundant in the caries-active group were Actinomyces sp. strain B19SC, Streptococcus mutans, and Lactobacillus spp., which exhibited an inverse relationship to beneficial bacterial species, such as Streptococcus parasanguinis, Abiotrophia defectiva, Streptococcus mitis, Streptococcus oralis, and Streptococcus sanguinis.

Reconstruction of surface profiles from their diffraction spectra.

A possible method for reconstruction of two-dimensional, periodic surface profiles, from their diffraction spectra is outlined. Formulas for the distribution of diffracted power, based on physical optics, are summarized and computed by approximating real profiles by piecewise linear functions. The profiles are reconstructed from measured spectra by a steepest descent method. A computer program searches for profiles whose spectra fit as close as possible to the measured spectra. For experimental demonstration a low-power CO(2) laser is used as radiation source, and the roughness profiles of a turned metal cylinder are reconstructed and compared with traced profile curves.