Variants on chromosome 4q21 near PKD2 and SIBLINGs are associated with dental caries

Association of polymicrobial interactions with dental caries development and prevention

Dental caries is a common oral disease. In many cases, disruption of the ecological balance of the oral cavity can result in the occurrence of dental caries. There are many cariogenic microbiota and factors, and their identification allows us to take corresponding prevention and control measures. With the development of microbiology, the caries-causing bacteria have evolved from the traditional single Streptococcus mutans to the discovery of oral symbiotic bacteria. Thus it is necessary to systematically organized the association of polymicrobial interactions with dental caries development. In terms of ecology, caries occurs due to an ecological imbalance of the microbiota, caused by the growth and reproduction of cariogenic microbiota due to external factors or the disruption of homeostasis by one's own factors. To reduce the occurrence of dental caries effectively, and considering the latest scientific viewpoints, caries may be viewed from the perspective of ecology, and preventive measures can be taken; hence, this article systematically summarizes the prevention and treatment of dental caries from the aspects of ecological perspectives, in particular the ecological biofilm formation, bacterial quorum sensing, the main cariogenic microbiota, and preventive measures.

PARTITIONING AROUND MEDOIDS CLUSTERING AND RANDOM FOREST CLASSIFICATION FOR GIS-INFORMED IMPUTATION OF FLUORIDE CONCENTRATION DATA

Community water fluoridation is an important component of oral health promotion, as fluoride exposure is a well-documented dental caries-preventive agent. Direct measurements of domestic water fluoride content provide valuable information regarding individuals' fluoride exposure and thus caries risk; however, they are logistically challenging to carry out at a large scale in oral health research. This article describes the development and evaluation of a novel method for the imputation of missing domestic water fluoride concentration data informed by spatial autocorrelation. The context is a state-wide epidemiologic study of pediatric oral health in North Carolina, where domestic water fluoride concentration information was missing for approximately 75% of study participants with clinical data on dental caries. A new machine-learning-based imputation method that combines partitioning around medoids clustering and random forest classification (PAMRF) is developed and implemented. Imputed values are filtered according to allowable error rates or target sample size, depending on the requirements of each application. In leave-one-out cross-validation and simulation studies, PAMRF outperforms four existing imputation approaches-two conventional spatial interpolation methods (i.e., inverse-distance weighting, IDW and universal kriging, UK) and two supervised learning methods (k-nearest neighbors, KNN and classification and regression trees, CART). The inclusion of multiply imputed values in the estimation of the association between fluoride concentration and dental caries prevalence resulted in essentially no change in PAMRF estimates but substantial gains in precision due to larger effective sample size. PAMRF is a powerful new method for the imputation of missing fluoride values where geographical information exists.

Genomics of periodontal disease and tooth morbidity

In this review we critically summarize the evidence base and the progress to date regarding the genomic basis of periodontal disease and tooth morbidity (ie, dental caries and tooth loss), and discuss future applications and research directions in the context of precision oral health and care. Evidence for these oral/dental traits from genome-wide association studies first emerged less than a decade ago. Basic and translational research activities in this domain are now under way by multiple groups around the world. Key departure points in the oral health genomics discourse are: (a) some heritable variation exists for periodontal and dental diseases; (b) the environmental component (eg, social determinants of health and behavioral risk factors) has a major influence on the population distribution but probably interacts with factors of innate susceptibility at the person-level; (c) sizeable, multi-ethnic, well-characterized samples or cohorts with high-quality measures on oral health outcomes and genomics information are required to make decisive discoveries; (d) challenges remain in the measurement of oral health and disease, with current periodontitis and dental caries traits capturing only a part of the health-disease continuum, and are little or not informed by the underlying biology; (e) the substantial individual heterogeneity that exists in the clinical presentation and lifetime trajectory of oral disease can be identified and leveraged in a precision medicine framework or, if unappreciated, can hamper translational efforts. In this review we discuss how composite or biologically informed traits may offer improvements over clinically defined ones for the genomic interrogation of oral diseases. We demonstrate the utility of the results of genome-wide association studies for the development and testing of a genetic risk score for severe periodontitis. We conclude that exciting opportunities lie ahead for improvements in the oral health of individual patients and populations via advances in our understanding of the genomic basis of oral health and disease. The pace of new discoveries and their equitable translation to practice will largely depend on investments in the education and training of the oral health care workforce, basic and population research, and sustained collaborative efforts..

WNT gene polymorphisms and predisposition to apical periodontitis

Single nucleotide polymorphisms (SNPs) in WNT genes may impact gene/protein function and contribute to individual predisposition to apical periodontitis (AP). Here, we investigated the association of SNPs in/nearby WNT3, WNT3A, WNT5A, WNT8A, WNT9B and WNT11 genes with AP using a case-control dataset. Cases were defined as individuals with deep caries and AP (n = 188); controls had deep caries and no AP (n = 230). Genotyping was performed using Taqman chemistry in real time PCR. Data analyses was performed using Fisher Exact tests assuming a Bonferroni correction threshold value of 0.005. Single-SNP association analysis revealed a trend for association with WNT3 rs9890413 genotypes (P = 0.009) under a dominant model and allelic association for WNT3A rs1745420 (P = 0.009). Haplotypes involving WNT3-WNT9B-WNT3A alleles were also significantly associated with AP (P ≤ 0.003). Luciferase reporter assays showed higher transcriptional activity (1.4-fold) with the alternate G allele in rs1745420. Expression of WNT3, WNT3A and WNT5A in AP tissues was significantly higher than in control tissues, and inversely correlated with the expression of SERPINB1, COL1A1 and TIMP1 (P < 0.05). Our results suggest that WNT genes have a role in modulating AP and polymorphisms in these genes may increase susceptibility to AP.

Association of ENAM, TUFT1, MMP13, IL1B, IL10 and IL1RN gene polymorphism and dental caries susceptibility in Chinese children

OBJECTIVE

To investigate the association between single nucleotide polymorphisms (SNPs) in six candidate genes (enamelin [ ENAM]; tuftelin 1 [ TUFT1]; matrix metallopeptidase 13 [ MMP13]; interleukin 1 beta [ IL1B]; interleukin 10 [ IL10]; interleukin 1 receptor antagonist [ IL1RN]) and dental caries in children from northwest China.

METHODS

This case-control study enrolled children (12-15 years) who underwent routine dental examinations. The children were divided into two groups based on the presence of dental caries. A saliva sample was collected and seven SNPs (rs3806804A/G in ENAM, rs3811411T/G in TUFT1, rs2252070A/G and rs597315A/T in MMP13, rs1143627C/T in IL1B, rs1800872A/C in IL10 and rs956730G/A in IL1RN) were genotyped.

RESULTS

A total of 357 children were enrolled in the study: 161 with dental caries and 196 without dental caries. No significant difference was found in the alleles and genotypes of five genes ( ENAM, TUFT1, MMP13, IL10 and IL1RN) between those with and without dental caries. A significant relationship was found between the IL1B rs1143627C/T polymorphism and dental caries susceptibility with those carrying the rs1143627CT genotype having a lower risk of dental caries compared with those carrying the CC genotype (odds ratio 0.557; 95% confidence interval 0.326, 0.952).

CONCLUSION

The IL1B rs1143627C/T polymorphism may be associated with dental caries susceptibility in children from northwest China.

Genome-Wide Association Study of Erosive Tooth Wear in a Finnish Cohort

Erosive tooth wear is defined as irreversible loss of dental tissues due to intrinsic or extrinsic acids, exacerbated by mechanical forces. Recent studies have suggested a higher prevalence of erosive tooth wear in males, as well as a genetic contribution to susceptibility to erosive tooth wear. Our aim was to examine erosive tooth wear by performing a genome-wide association study (GWAS) in a sample of the Northern Finland Birth Cohort 1966 (n = 1,962). Erosive tooth wear was assessed clinically using the basic erosive wear examination. A GWAS was performed for the whole sample as well as separately for males and females. We identified one genome-wide significant signal (rs11681214) in the GWAS of the whole sample near the genes PXDN and MYT1L. When the sample was stratified by sex, the strongest genome-wide significant signals were observed in or near the genes FGFR1, C8orf86, CDH4, SCD5, F2R, and ING1. Additionally, multiple suggestive association signals were detected in all GWASs performed. Many of the signals were in or near the genes putatively related to oral environment or tooth development, and some were near the regions considered to be associated with dental caries, such as 2p24, 4q21, and 13q33. Replications of these associations in other samples, as well as experimental studies to determine the biological functions of associated genetic variants, are needed.