Dental caries in a Norwegian adult population, the HUNT4 oral health study; prevalence, distribution and 45-year trends.

OBJECTIVE: To investigate dental caries prevalence amongst adults in Central Norway and assess changes over the last 45 years. MATERIALS AND METHODS: The cross-sectional HUNT4 Oral Health Study was conducted in 2017-2019. A random sample of 4913 participants aged ≥19 years answered questionnaires and underwent clinical and radiographic examinations. Data were compared to findings from previous studies in the same region conducted from 1973 to 2006. RESULTS: Mean number of decayed, missing and filled teeth (D3-5MFT) was 14.9 (95% CI 14.7, 15.1), 56% of adults had one or more carious teeth (D3-5T) and 11.8% had ≥4 D3-5T, with the mean number of 1.4 (95% CI 1.32, 1.42). For initial caries, mean D1-2S was 3.8 (95% CI 3.7, 3.9), being the highest for 19-24-year-olds at 8.6 (95% CI 7.9, 9.3). Comparisons with earlier studies showed a decline in mean D3-5MFT for 35-44-year-olds from 26.5 in 1973 to 10.8 in 2019. In 1973, 4.8% of 35-44-year-olds were edentulous, while in present study edentulousness was found only in individuals >65 years. CONCLUSIONS: Despite a substantial reduction in caries experience over the last 45 years, untreated dentine caries was common, evenly distributed across all age groups. Initial caries particularly affected younger individuals, indicating a need to evaluate prevention strategies and access to dental services.

Association between periodontitis stages and self-reported diseases in a Norwegian population: the HUNT study.

BACKGROUND: The relationships between periodontitis and non-communicable diseases (NCDs) have been investigated through several different case-definitions. The differences in methodology may have hindered the basis of comparison between these studies. The classification from the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions offers a unison platform that may facilitate future comparison of such research. The present study aimed to reproduce associations between periodontitis and other NCDs using the 2017 Classification, in the Trøndelag Health Study (HUNT). MATERIAL AND METHODS: The fourth HUNT-survey was carried out between 2017 and 2019. Clinical variables, blood samples and answers to questionnaires were collected from 4933 participants. Periodontal status was assessed based on the latest staging system, and its associations with NCDs were estimated by logistic regression models adjusted for potential confounders. RESULTS: Compared to no or Stage I periodontitis, participants with Stage III/IV periodontitis (radiographic bone loss exceeding 33%) were associated with cardiovascular disease, hyperglycemia in participants with diabetes and chronic obstructive pulmonary disease (COPD)/emphysema. Associations with hyperglycemia in participants with diabetes and COPD/emphysema were also observed in participants with Stage II periodontitis. The only observed association when considering never-smokers alone, was with COPD/emphysema. CONCLUSION: Periodontitis Stage II and III/IV were associated with major NCDs. Effect sizes increased with increasing periodontitis stages, which implies greater occurrence of coincident comorbidities in patients with severe periodontitis.

Associations of adverse childhood experiences with caries and toothbrushing in adolescents. The Young-HUNT4 Survey.

BACKGROUND: Adverse childhood experiences (ACEs) are associated with poor oral health. Using a life course theoretical framework, this study explored the associations of specific and cumulative ACEs with caries and toothbrushing frequency in a Norwegian adolescent population. METHODS: Participants were adolescents (n = 6351) age 13-17 years from The Young-HUNT4 Survey. Clinical data were retrieved from dental health records. Oral health outcomes were toothbrushing frequency, dentine caries experience (Decayed, Missing, and Filled Teeth - DMFT), and enamel caries. ACE exposure variables were physical abuse, sexual abuse, witness to violence, parental separation/divorce, parental alcohol problems, and bully victimization. Negative binominal regression models (incident rate ratios, IRRs; 95% confidence intervals, CIs) were used to determine the associations of the various ACEs with caries; logistic regression analyses (odds ratios, ORs; 95% CIs) were used to estimate associations with toothbrushing frequency. Potential effect modification by age was assessed using likelihood ratio test. RESULTS: Adolescents exposed to physical abuse by others, sexual abuse by peers, parental separation/divorce, bullying, or who had witnessed violence, were more likely to report non-daily toothbrushing compared with those with no exposure to the given ACEs. Each cumulative increase in ACE exposure was associated with a 30% higher likelihood of non-daily toothbrushing (OR 1.30, 95% CI 1.19-1.42). Similarly, increasing number of adversities were associated with both higher dentine caries experience (IRR 1.06, 95% CI 1.02-1.09) and higher enamel caries (IRR 1.07, 95% CI 1.03-1.11). This effect was modified by age (13-15 vs. 16-17 years) for dentine caries experience. Furthermore, there was evidence of effect modification by age with bully victimization for both toothbrushing frequency (Pinteraction = 0.014) and dentine caries experience (Pinteraction < 0.001). Specifically, bully victimization was associated with a higher likelihood of non-daily toothbrushing (OR 2.59, 95% CI 1.80-3.72) and higher dentine caries experience (IRR 1.30, 95% CI 1.14-1.50) among 16-17-year-olds. CONCLUSIONS: Several specific ACEs were associated with non-daily toothbrushing and a higher caries experience among Norwegian adolescents in the Young-HUNT4 Survey.

Dental caries at enamel and dentine level among European adolescents - a systematic review and meta-analysis.

BACKGROUND: In contrast with the last century, caries epidemiology has begun integrating enamel caries into determinations of caries prevalence and experience. The objective of the present systematic review and meta-analysis was to assess the caries status including estimations of enamel caries, of European adolescents. METHOD: Four databases (Medline Ovid, Embase, CINAHL, and SweMed+) were systematically searched from 1 January 2000 through 20 September 2021 for peer-reviewed publications on caries prevalence and caries experience in 12-19-year-olds; that also included evaluations of enamel lesions. Summary estimates were calculated using random effect model. RESULTS: Overall, 30 publications were selected for the systematic review covering 25 observational studies. Not all studies could be used in the meta-analyses. Caries prevalence was 77% (n = 22 studies). Highest prevalence was reported in the age groups 16-19 years, and in studies where caries examinations were done before 2010. The overall mean DMFT score was 5.93 (n = 14 studies) and it was significantly lower among Scandinavian adolescents than among other European adolescents (4.43 vs. 8.89). The proportion of enamel caries (n = 7 studies) was 50%, and highest in the lowest age group (12-15 years). Results from the present systematic review reflected the caries distribution to be skewed at individual-, tooth- and surface levels; at tooth and surface level, also changed according to age. CONCLUSIONS: Although studies in which the caries examinations had been done in 2010 or later documented a reduction in caries prevalence, caries during adolescence still constitutes a burden. Thus, the potential for preventing development of more severe caries lesions, as seen in the substantial volume of enamel caries during early adolescence, should be fully exploited. For this to happen, enamel caries should be a part of epidemiological reporting in national registers.

The validity of self-reported number of teeth and edentulousness among Norwegian older adults, the HUNT Study.

BACKGROUND: Number of teeth is an established indicator of oral health and is commonly self-reported in epidemiological studies due to the costly and labor-intensive nature of clinical examinations. Although previous studies have found self-reported number of teeth to be a reasonably accurate measure, its accuracy among older adults ≥ 70 years is less explored. The aim of this study was to assess the validity of self-reported number of teeth and edentulousness in older adults and to investigate factors that may affect the accuracy of self-reports. METHODS: This study included two different samples of older adults ≥ 70 years drawn from the fourth wave of the Trøndelag Health Study (the HUNT Study), Norway. Sample 1 (n = 586) was used to evaluate the validity of self-reported number of teeth and sample 2 (n = 518) was used to evaluate self-reported edentulousness. Information on number of teeth and background variables (education, smoking, cognitive function, and self-perceived general and oral health) were self-reported in questionnaires, while clinical oral health examinations assessed number of teeth, number of teeth restored or replaced by fixed prosthodontics and edentulousness. Spearman and Pearson correlation coefficients, Bland-Altman plot, chi-square test and kappa statistics were used to assess the agreement between self-reported and clinically recorded number of teeth. RESULTS: The mean difference between self-reported and clinically recorded number of teeth was low (- 0.22 teeth), and more than 70% of the participants reported their number of teeth within an error of two teeth. Correlations between self-reports and clinical examinations were high for the total sample (0.86 (Spearman) and 0.91 (Pearson)). However, a lower correlation was found among participants with dementia (0.74 (Spearman) and 0.85 (Pearson)), participants having ≥ 20 teeth (0.76 (Spearman) and 0.67 (Pearson)), and participants with ≥ 5 teeth restored or replaced by fixed prosthodontics (0.75 (Spearman) and 0.77 (Pearson)). Self-reports of having teeth or being edentulous were correct in 96.3% of the cases (kappa value 0.93, p value < 0.001). CONCLUSIONS: Among older Norwegian adults, self-reported number of teeth agreed closely with clinical tooth counts and nearly all the edentulous participants correctly reported having no teeth.

Prevalence of periodontitis based on the 2017 classification in a Norwegian population: The HUNT study.

AIM: This cross-sectional study assesses the prevalence of periodontitis in a large Norwegian population, based on the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. The prevalence of periodontitis was determined by bone loss recorded on radiographs (orthopantomogram [OPG] and bitewing [BW]) and by clinical examination. MATERIALS AND METHODS: As part of a large population health study (The HUNT Study), 7347 participants aged 19 years and older were invited to the HUNT4 Oral Health Study. Radiographic bone loss (RBL) and periodontal stage and grade were assessed in 4863 participants. RESULTS: Periodontal examination was performed in 4863 participants. RBL and clinical registrations corresponding to periodontitis as defined were observed in 72.4%. The prevalence of periodontitis increased after 40 years of age, with severe forms occurring primarily after 60 years of age. Stage I was observed in 13.8%, Stage II in 41.1%, Stage III in 15.3%, and Stage IV in 2.3% of the population. Grade A, B, and C was observed in 5.7%, 60.2%, and 6.2%, respectively. CONCLUSION: Periodontitis was frequently observed in the investigated population. The prevalence of periodontitis Stage III and Stage IV combined was observed in 17.6% of the study population.

Exploring socioeconomic inequality in caries experience in an adult Norwegian population; the HUNT4 Oral Health Study.

OBJECTIVES: To investigate socioeconomic inequality in caries experience in an adult Norwegian population. METHODS: This population-based study included 4549 dentate participants aged 25-94 years from the cross-sectional HUNT4 Oral Health Study conducted in Central Norway in 2017-2019. Participants were randomly sampled from the larger HUNT4 Survey and answered questionnaires and underwent clinical and radiographic examinations. Caries experience was measured as numbers of decayed, missing and filled teeth (DMFT index) and socioeconomic position was denoted by education and household income. Negative binomial regression models were used to estimate associations between caries experience and socioeconomic position. RESULTS: Lower levels of both education and income were associated with higher caries experience, particularly pronounced for missing teeth. Socioeconomic gradients were observed for all outcomes DMFT, DT, MT and FT (p-value linear trends <.001). Gradients were similar for both income and education and were apparent for all age groups but were most evident in middle-aged and older individuals. High level of education was associated with a 50% lower mean number of missing teeth compared with basic level education, whereas high income was associated with a 24% lower mean number of decayed teeth and a 15% higher mean number of filled teeth than low income. CONCLUSIONS: There was a socioeconomic gradient for caries experience in the study population that was present from early adulthood and increased with age. The gradient was particularly pronounced for missing teeth. Findings indicate that inequality was more associated with treatment given than with untreated disease.

Undiagnosed Celiac Disease and Periodontal Bone Loss: A Cross-Sectional Radiological Assessment from the HUNT Study.

Objective: The objective was to assess radiographic periodontal bone loss in a population with previously undiagnosed celiac disease, and to compare it to a reference group without celiac disease. Background: Periodontitis and celiac disease are chronic inflammatory diseases with possible similar features related to immune reactions and microbial dysbiosis. The relationship between these two diseases is not clear. Methods: Clinical variables, blood samples, and answers to questionnaires were collected from participants in the fourth Trøndelag Health Study (HUNT4). Celiac disease was determined based on transglutaminase 2 (TG2), immunoglobulin A (IgA), and G (IgG) in serum samples. Seropositive individuals were invited to endoscopic examination and tissue sampling. Radiographically assessed bone loss caused by periodontitis in two different levels of severity was applied as outcome, that is, ≥15% and >33% of root length. Bone loss was determined in panoramic images in participants that had attended radiographic examination in the HUNT4 Oral Health Study or in the HUNT4 Coeliac Disease Study. The association between previously undiagnosed celiac disease and radiographic bone loss was estimated by adjusted Poisson regression models. Results: Radiographic assessment was completed in 485 individuals with celiac disease determined by positive serology and in 4,727 individuals with negative serology (without celiac disease). Compared to nonceliacs, seropositive participants were less likely to present with ≥15% radiographic bone loss (prevalence ratio (PR) 0.89 (95% CI 0.84-0.96). A similar association was also observed after histopathological confirmation of celiac disease (PR 0.89 (95% CI 0.82-0.98). No association between undiagnosed celiac disease and periodontal bone loss was observed when analyses were limited to individuals with severe bone loss (>33%). Conclusion: In this study of previously undiagnosed celiac disease and periodontal bone loss, newly diagnosed celiac disease was associated with less likelihood of presenting with ≥15% radiographic bone loss compared to a nonceliac reference group.

Associations of Serum Vitamin D With Dental Caries and Periodontitis: The HUNT Study.

OBJECTIVE: To study the relationships of serum 25-hydroxyvitamin D [25(OH)D] with dental caries and periodontitis in a general Norwegian adult population. METHODS: We analysed a subsample of 1605 participants from the Trøndelag Health Study (HUNT) in Norway that had serum 25(OH)D levels measured in HUNT3 (2006-08) and oral health assessed in the HUNT4 Oral Health Study (2017-19). Negative binomial and Poisson regression models were used to estimate the ratios of means (RMs; for count oral outcomes) and prevalence ratios (PRs; for dichotomous oral outcomes). RESULTS: Serum 25(OH)D was inversely associated with the number of decayed teeth in a dose-response gradient (<30.0 nmol/L: RM 1.41, 95% CI 1.07-1.85; 30.0-49.9 nmol/L: 1.14, 0.98-1.32 and ≥75.0 nmol/L: 0.84, 0.67-1.04, as compared to the 50.0-74.9 nmol/L group, P for trend <.001). Each 25 nmol/L decrease in 25(OH)D level was associated with a 15% (RM 1.15, 95% CI 1.05-1.26) increase in the mean number of decayed teeth. Serum 25(OH)D <30.0 nmol/L was associated with a 35% higher prevalence of severe periodontitis (PR 1.35, 95% CI 1.00-1.83). No association was observed between 25(OH)D and the number of natural teeth. CONCLUSION: The present study suggested that serum 25(OH)D level had an inverse and dose-response association with the number of decayed teeth, and serum 25(OH)D <30 nmol/L was associated with a higher prevalence of severe periodontitis in this Norwegian adult population.

Comprehensive transcriptome analysis of the periodontopathogenic bacterium Porphyromonas gingivalis W83.

High-density tiling microarray and RNA sequencing technologies were used to analyze the transcriptome of the periodontopathogenic bacterium Porphyromonas gingivalis. The compiled P. gingivalis transcriptome profiles were based on total RNA samples isolated from three different laboratory culturing conditions, and the strand-specific transcription profiles generated covered the entire genome, including both protein coding and noncoding regions. The transcription profiles revealed various operon structures, 5'- and 3'-end untranslated regions (UTRs), differential expression patterns, and many novel, not-yet-annotated transcripts within intergenic and antisense regions. Further transcriptome analysis identified the majority of the genes as being expressed within operons and most 5' and 3' ends to be protruding UTRs, of which several 3' UTRs were extended to overlap genes carried on the opposite/antisense strand. Extensive antisense RNAs were detected opposite most insertion sequence (IS) elements. Pairwise comparative analyses were also performed among transcriptome profiles of the three culture conditions, and differentially expressed genes and metabolic pathways were identified. With the growing realization that noncoding RNAs play important biological functions, the discovery of novel RNAs and the comprehensive transcriptome profiles compiled in this study may provide a foundation to further understand the gene regulation and virulence mechanisms in P. gingivalis. The transcriptome profiles can be viewed at and downloaded from the Microbial Transcriptome Database website, http://bioinformatics.forsyth.org/mtd.

Strand-specific transcriptome profiling with directly labeled RNA on genomic tiling microarrays.

BACKGROUND: With lower manufacturing cost, high spot density, and flexible probe design, genomic tiling microarrays are ideal for comprehensive transcriptome studies. Typically, transcriptome profiling using microarrays involves reverse transcription, which converts RNA to cDNA. The cDNA is then labeled and hybridized to the probes on the arrays, thus the RNA signals are detected indirectly. Reverse transcription is known to generate artifactual cDNA, in particular the synthesis of second-strand cDNA, leading to false discovery of antisense RNA. To address this issue, we have developed an effective method using RNA that is directly labeled, thus by-passing the cDNA generation. This paper describes this method and its application to the mapping of transcriptome profiles. RESULTS: RNA extracted from laboratory cultures of Porphyromonas gingivalis was fluorescently labeled with an alkylation reagent and hybridized directly to probes on genomic tiling microarrays specifically designed for this periodontal pathogen. The generated transcriptome profile was strand-specific and produced signals close to background level in most antisense regions of the genome. In contrast, high levels of signal were detected in the antisense regions when the hybridization was done with cDNA. Five antisense areas were tested with independent strand-specific RT-PCR and none to negligible amplification was detected, indicating that the strong antisense cDNA signals were experimental artifacts. CONCLUSIONS: An efficient method was developed for mapping transcriptome profiles specific to both coding strands of a bacterial genome. This method chemically labels and uses extracted RNA directly in microarray hybridization. The generated transcriptome profile was free of cDNA artifactual signals. In addition, this method requires fewer processing steps and is potentially more sensitive in detecting small amount of RNA compared to conventional end-labeling methods due to the incorporation of more fluorescent molecules per RNA fragment.

A hidden Markov support vector machine framework incorporating profile geometry learning for identifying microbial RNA in tiling array data.

MOTIVATION: RNA expression signals detected by high-density genomic tiling microarrays contain comprehensive transcriptomic information of the target organism. Current methods for determining the RNA transcription units are still computation intense and lack the discriminative power. This article describes an efficient and accurate methodology to reveal complicated transcriptional architecture, including small regulatory RNAs, in microbial transcriptome profiles. RESULTS: Normalized microarray data were first subject to support vector regression to estimate the profile tendency by reducing noise interruption. A hybrid supervised machine learning algorithm, hidden Markov support vector machines, was then used to classify the underlying state of each probe to 'expression' or 'silence' with the assumption that the consecutive state sequence was a heterogeneous Markov chain. For model construction, we introduced a profile geometry learning method to construct the feature vectors, which considered both intensity profiles and changes of intensities over the probe spacing. Also, a robust strategy was used to dynamically evaluate and select the training set based only on prior computer gene annotation. The algorithm performed better than other methods in accuracy on simulated data, especially for small expressed regions with lower (<1) SNR (signal-to-noise ratio), hence more sensitive for detecting small RNAs. AVAILABILITY AND IMPLEMENTATION: Detail implementation steps of the algorithm and the complete result of the transcriptome analysis for a microbial genome Porphyromonas gingivalis W83 can be viewed at http://bioinformatics.forsyth.org/mtd.

Dynamic probe selection for studying microbial transcriptome with high-density genomic tiling microarrays.

BACKGROUND: Current commercial high-density oligonucleotide microarrays can hold millions of probe spots on a single microscopic glass slide and are ideal for studying the transcriptome of microbial genomes using a tiling probe design. This paper describes a comprehensive computational pipeline implemented specifically for designing tiling probe sets to study microbial transcriptome profiles. RESULTS: The pipeline identifies every possible probe sequence from both forward and reverse-complement strands of all DNA sequences in the target genome including circular or linear chromosomes and plasmids. Final probe sequence lengths are adjusted based on the maximal oligonucleotide synthesis cycles and best isothermality allowed. Optimal probes are then selected in two stages - sequential and gap-filling. In the sequential stage, probes are selected from sequence windows tiled alongside the genome. In the gap-filling stage, additional probes are selected from the largest gaps between adjacent probes that have already been selected, until a predefined number of probes is reached. Selection of the highest quality probe within each window and gap is based on five criteria: sequence uniqueness, probe self-annealing, melting temperature, oligonucleotide length, and probe position. CONCLUSIONS: The probe selection pipeline evaluates global and local probe sequence properties and selects a set of probes dynamically and evenly distributed along the target genome. Unique to other similar methods, an exact number of non-redundant probes can be designed to utilize all the available probe spots on any chosen microarray platform. The pipeline can be applied to microbial genomes when designing high-density tiling arrays for comparative genomics, ChIP chip, gene expression and comprehensive transcriptome studies.