Single Nucleotide Polymorphism in the Aetiology of Caries: Systematic Literature Review

Genetics Affecting the Prognosis of Dental Treatments

Genetics plays a significant role in determining an individual's susceptibility to dental diseases, the response to dental treatments, and the overall prognosis of dental interventions. Here, the authors explore the various genetic factors affecting the prognosis of dental treatments focusing on dental caries, orthodontic treatment, oral cancer, prosthodontic treatment, periodontal disease, developmental disorders, pharmacogenetics, and genetic predisposition to faster wound healing. Understanding the genetic underpinnings of dental health can help personalize treatment plans, predict outcomes, and improve the overall quality of dental care.

Association between LTF/MMP20/CA6/TAS1R2 polymorphisms and susceptibility to dental caries

OBJECTIVES

The aim was to assess the associations between the LTF, MMP20, CA6, and TAS1R2 polymorphisms and caries in the Zhuang population and explore the underlying mechanism of the impact of lactoferrin on caries susceptibility.

METHODS

A case-control study of 315 adolescents was conducted in Guangxi, China, from May-November 2022. Data were collected through oral examinations and questionnaires. Buccal mucosa cells and DNA samples were collected using the SNPscan technique. Saliva and supragingival plaque samples were taken from 69 subjects with various LTF rs10865941 genotypes. The relationships among the LTF rs10865941 polymorphism, lactoferrin, Streptococcus mutans, and caries were investigated by using the ELISA and qRT-PCR, along with logistic regression analysis.

RESULTS

The genotype distribution of the LTF gene were significantly different between the case and control groups (p = 0.018). The case group had lower C allele and greater T allele frequencies than the control group (p = 0.006). The LTF rs10865941 polymorphism was associated with caries in the codominant, dominant, and additive models (p < 0.05). MMP20 rs1784418, CA6 rs2274328, and TAS1R2 rs35874116 were not significantly different between the two groups (p > 0.05). A greater quantity of S. mutans. in the supragingival plaque was found in the case group (p = 0.03). There were significant differences between the two groups in both the codominant model and the dominant model (p < 0.05).

CONCLUSIONS

The LTF rs10865941 polymorphism may be associated with caries susceptibility in the Zhuang population of China. The LTF rs10865941 T allele may be a potential risk factor for dental caries.

Activity and levels of TNF-α, IL-6 and IL-8 in saliva of children and young adults with dental caries: a systematic review and meta-analysis

BACKGROUND

Cytokines play an important role in the immunopathogenesis of dental caries. A systematic review and meta-analysis was carried out with the following three objectives: 1)To deepen and discuss through a comprehensive analysis of the literature the effects of dental caries on the activity and levels of TNF-α, IL-6 and IL-8 in saliva of children and young adults, 2)To compare the levels of this cytokines in saliva of the exposure group (moderate-severe dental caries) with the control group (caries-free or mild dental caries), and 3)To determine whether the levels of these cytokines could be used as a complementary clinical diagnostic tool to assess the severity of dental caries.

METHODS

The protocol followed PRISMA and Cochrane guidelines and was registered in the Open Science Framework (OSF): https://doi.org/10.17605/OSF.IO/MF74V . A digital search was performed in PubMed/MEDLINE, Cochrane, Scopus, and Google Schoolar databases from February 15th, 2012, to January 13th, 2024. The methodological validity of the selected studies was assessed using Joanna Briggs Institute (JBI) tool. A meta-analysis was performed using a random-effects model to evaluate the association between dental caries/health, and the concentration of TNF-α, IL-6 and IL-8.

RESULTS

The search strategy provided a total of 126 articles, of which 15 investigations met the inclusion criteria. The total number of patients studied was 1,148, of which 743 represented the case/exposure group, and 405 represented the control group. The age of the patients ranged from 3 to 25 years. IL-6 was the most prevalent cytokine in the saliva of children and young adults with active dental caries. The meta-analysis revealed that there are significant differences between the levels of IL-6 and TNF-α in saliva of children with active dental caries compared to their control groups.

CONCLUSIONS

The findings suggest that IL-6 and TNF-α levels may have potential as complementary biomarkers for assessing dental caries severity. However, further research is needed to validate these findings in larger and more diverse populations before clinical application.

Polymorphisms in ENAM, AMBN, and KLK4 predispose Egyptian adults to dental caries: A cross-sectional study

Objective

This study investigates the distributional discrepancies of four single-nucleotide polymorphic loci as correlatives and causatives of dental caries susceptibility among Egyptians.

Method

We conducted a cross-sectional study through the genotyping of enamelin (ENAM rs3796703), ameloblastin (AMBN rs4694075), tuftelin 1 (TUFT1 rs78802584), and kallikrein 4 (KLK4 rs2242670) in 132 adults (males = 74, females = 58) and 72 controls (males = 40, females = 32) referred from various Egyptian hospitals. For each participant, the number of decayed, missing, and filled teeth was charted, and the presence of biofilm/gingivitis/fluorosis was assessed. Bitewing radiographs were taken to detect interproximal caries. In addition, statistical analysis was conducted using Chi-square test, odds ratios, and corresponding P-values.

Results

The alleles and genotypes of ENAM rs3796703, AMBN rs4694075, and KLK4 rs2242670 correlated strongly with dental caries susceptibility. However, TUFT1 rs78802584 did not exhibit such associations.

Conclusion

These findings suggest the potential role of ENAM, AMBN, and KLK4 as determinants of dental caries susceptibility among Egyptian adults. The role of ENAM, AMBN, and KLK4 genetic variants is determinant in influencing susceptibility to dental caries in the Egyptian population, providing valuable insights into the genetic aspects of oral health. However, the lack of associations of caries susceptibility with TUFT1 rs78802584 contradicts its cariogenic role in many ethnicities.

Dental caries prevalence and severity positively associate with AMY1 gene copy number

OBJECTIVE

To establish the possible relation between total caries (TC) and caries severity (CS) with the AMY1 gene copy number (AMY1GCN).

MATERIALS AND METHODS

This was an observational, cross-sectional, population-based, and association study with 303 participants. Each participant underwent a complete anamnesis and stomatological check-up, and peripheral blood was obtained to extract gDNA. TC and CS were determined as the number of caries at the dental exploration and the number of dental surfaces affected by caries, respectively, and AMY1GCN was determined by qPCR.

RESULTS

We found an elevated caries prevalence (92.7%); TC and CS were 8 ± 10 and 10 ± 13 (median ± IR). There were higher TC and CS in those participants with AMY1GCN above the mean value (0.02 and 0.01 p values, respectively). A positive correlation between TC and CS with AMY1GCN (0.11 and 0.125 r values, 0.03 and 0.01 p values, respectively) was found, in addition to an association between TC and CS with AMY1GCN (1.5 and 1.6 OR values, 0.48 and 0.26 p values, respectively).

CONCLUSION

TC and CS were positively related to the AMY1GCN.

CLINICAL RELEVANCE

Dental caries has a high prevalence and a multifactorial etiology and has been related to a genetic component. Indeed, the salivary enzyme alpha-amylase could play a significant role in caries susceptibility, considering that its codifying gene (AMY1) can show variation in its gene copy number. This can be considered an important factor for the development of caries at a genetic level.

Association between polymorphisms of immune response genes and early childhood caries - systematic review, gene-based, gene cluster, and meta-analysis

BACKGROUND

Early childhood caries is a significant public health concern affecting about 600 million children globally. The etiology of early childhood caries can be explained as an interplay between genetic and environmental factors. Single nucleotide polymorphisms are the most common variations in the human genome. Genetic variations of immune response genes can modify the defense response of the host, and alter the susceptibility to bacterial colonization of the oral cavity and early childhood caries. The aim of this systematic review is to identify genetic variants of immune response genes associated with early childhood caries.

RESULTS

A total of 7124 articles were identified by conducting an elaborate search across various electronic databases and genome-wide association studies databases. Subsequent to exclusion at various stages, fifteen articles qualified to be included into the present review. Risk of bias assessment was done with the Q-genie tool. Quantitative synthesis revealed that the odds ratio for TT and CC genotypes of rs11362 was 1.07 (0.67-1.71) and 1.16 (0.84-1.60), respectively. Gene-based analysis revealed a statistically significant association between variants of tumor necrosis factor-alpha gene and T-cell receptor alpha variable 4 locus with early childhood caries. Gene clustering showed the presence of three functional clusters. To comprehend the protein-protein interaction, the bioinformatic tool of "Search Tools for the Retrieval of Interacting Genes and Proteins" was used. Among the biological processes and the reactome pathways, complement activation through the lectin pathway showed the highest strength of association with early childhood caries. To understand the interaction and functionality of the genes, "gene function prediction using Multiple Association Network Integration Algorithm" was used, which revealed that the genes were linked by physical interaction (39.34%) and through co-expression (34.88%).

CONCLUSIONS

Genotype TT of rs7217186 of arachidonate 15-lipoxygenase gene was a risk factor for early childhood caries. Multiple genetic variants of T-cell receptor alpha variable 4 locus and tumor necrosis factor-alpha gene were associated with increased susceptibility to early childhood caries. Polymorphisms of genes regulating the lectin pathway of complement activation can modify the susceptibility to early childhood caries.

The association between MMP-13 rs478927 gene polymorphism and dental caries susceptibility in children with mixed dentition from Birjand, Iran: A case-control study

Background and Aims

Gene polymorphisms are responsible for at least part of the variation in caries susceptibility despite similar environmental factors. Genes involved in enamel formation like matrix metalloproteinase-13 (MMP-13) may participate in caries process. The aim was to investigate the association between MMP-13 rs478927 polymorphism and caries susceptibility in 6-years-old children from Birjand, Iran.

Methods

Six-years old children from Birjand, Iran, participated in this study. The total decayed, missing, and filled teeth were calculated and defined as caries index (CI). Based on this CI, two groups of high-caries (case) and low-caries (control) were taken into account. Saliva samples were collected and DNA was extracted. The allele and genotypes of MMP-13 rs478927 polymorphism were determined by tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) method. p Value was significant if p < 0.05.

Results

Three hundred sixty-seven children consisted of 186 low-caries children and 181 high-caries children were included in this study. The mean CI was 6.02 ± 0.81. There was no significant association between high and low-caries groups based on socioeconomic status, eating sweet snacks, parents' susceptibility to dental caries, duration of breastfeeding, and the brushing habit (p > 0.05). There wasn't any significant association between genotype distribution of MMP-13 rs478927 polymorphism and CI groups (p = 0.924). This polymorphism was associated with increased caries susceptibility under all genetic models but this effect was not significant (p > 0.05).

Conclusion

The MMP-13 rs478927 gene polymorphism was not significantly associated with dental caries susceptibility in Birjandi children with mixed dentition. It is recommended to conduct studies on children of different dentitions to better understand the role of this polymorphism on caries susceptibility in primary and permanent teeth of children.

Associations of the activity and concentration of carbonic anhydrase VI with susceptibility to dental caries: A systematic review and meta-analysis

OBJECTIVES

A number of studies have claimed that carbonic anhydrase VI (CA VI) is associated with dental caries. The aim of this systematic review and meta-analysis was to systematically review and analyze the literature on the association of CA VI (in terms of concentration and activity) with dental caries.

MATERIALS AND METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant search terms were employed to search the following databases: PubMed, Web of Science, Scopus, China National Knowledge Infrastructure (CNKI), and Cochrane Library databases. Eligible publications from inception to August 2022 were included. The relevant records were assessed independently by two reviewers, and a meta-analysis was performed using RevMan 5.3.

RESULTS

Out of 237 relevant records from the initial search, 9 met the criteria for this review. The 9 papers, including 477 participants, were qualitatively analyzed. Seven studies with 411 participants (203 caries-free) were included in the meta-analysis on CA VI activity, and 2 studies with 141 participants (71 caries-free) were included in the meta-analysis on CA VI concentration. The results showed that CA VI activity was significantly higher among participants with caries than their caries-free counterparts (standardized mean difference (SMD) = 0.894, 95% confidence interval (CI_95% ): 0.386 and 1.392; p < 0.001), whereas the CA VI concentration was significantly lower among participants with caries than their caries-free counterparts (SMD = -0.672, CI_95% : -1.011 and -0.332; p < 0.001).

CONCLUSIONS

This meta-analysis of a relatively small number of studies suggests that the CA VI concentration is lower and CA VI activity is higher in patients with dental caries than in caries-free individuals; however, further studies are needed to determine the exact role of CA VI in dental caries.

Evaluation of Beta-Defensin 1 and Mannose-Binding Lectin 2 Polymorphisms in Children with Dental Caries Compared to Caries-Free Controls: A Systematic Review and Meta-Analysis

Background and objective: Some variants in defensin beta 1 (DEFB1) and mannose-binding lectin 2 (MBL2) genes can be associated with oral diseases. Herein, we designed a systematic review and meta-analysis to evaluate the association of DEFB1 (rs11362, rs1799946, and rs1800972) and MBL2 (rs7096206 and rs1800450) polymorphisms with the susceptibility to dental caries (DC) in children. Materials and methods: A systematic literature search was conducted in the PubMed/Medline, Web of Science, Scopus, and Cochrane Library databases until 3 December 2022, without any restrictions. The odds ratio (OR), along with a 95% confidence interval (CI) of the effect sizes, are reported. Analyses including a subgroup analysis, a sensitivity analysis, and funnel plot analyses were conducted. Results: A total of 416 records were identified among the databases, and nine articles were entered into the meta-analysis. A significant relationship was found between the T allele of DEFB1 rs11362 polymorphism and DC susceptibility, and the T allele was related to an elevated risk of DC in children (OR = 1.225; 95%CI: 1.022, 1.469; p = 0.028; I² = 0%). No other polymorphisms were associated with DC. All articles were of moderate quality. Egger's test in homozygous and dominant models demonstrated a significant publication bias for the association of DEFB1 rs1799946 polymorphism with DC risk. Conclusions: The results demonstrated that the T allele of DEFB1 rs11362 polymorphism had an elevated risk for DC in children. However, there were only few studies that evaluated this association.

Genes and single nucleotide polymorphisms in the pathway of saliva and dental caries: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to investigate the influence of single nucleotide polymorphisms (SNPs), related to genes in salivary composition and flow, on dental caries experience. Sixteen studies were included in the systematic review and ten in the meta-analysis. Forty-four SNPS, covering four genes (CA6, AQP2, AQP5, and MUC5B) were identified. Most of the SNPs were not associated with caries in meta-analysis. Homozygous TT genotype of the SNP CA6 rs17032907(C/T) was associated with caries [OR = 3.23(1.39-7.49)]. The pool effect of the SNPs assessed in AQP5 was associated with a reduction in the likelihood of caries [OR = 0.75(0.59-0.95)]. Considering all SNPs of salivary composition and flow, the effect allele was associated with a 75% increase in the likelihood of caries [OR = 1.75(1.06-2.89)] in the homozygous genotype. The present findings showed that the genes in salivary composition and flow can play an important role in dental caries experience.

Single nucleotide polymorphisms of enamel formation genes and early childhood caries - systematic review, gene-based, gene cluster and meta-analysis

Introduction

Genetic polymorphisms of genes regulating amelogenesis can alter susceptibility to Early Childhood Caries (ECC). This systematic review aims to analyze associations between single-nucleotide polymorphisms of enamel formation genes and ECC.

Methods

Search was conducted across PUBMED, CINAHL, LILACS, SCOPUS, EMBASE, Web of Science, Genome-Wide Association Studies databases from January 2003 to September 2022. This was supplemented by hand search. Totally 7124 articles were identified and 21 articles that satisfied the inclusion criteria proceeded to data extraction. Quality assessment was done using the Q-Genie tool.

Results

Quantitative synthesis revealed that homozygous genotype AA of rs12640848 was significantly higher in children with ECC with an odds ratio of 2.36. Gene-based analysis revealed significant association between six variants of AMBN, four variants of KLK4, two variants of MMP20, and a single variant of each of MMP9 and MMP13 genes and ECC. The Bonferroni corrected-log10 P value of amelogenesis gene Cluster was 2.25 (0.05/88 = 5.6 × 10^-4). Search Tool for Retrieval of Interacting Genes and Proteins plot constructed to comprehend the protein-protein interaction revealed the presence of four functional clusters. Gene function prediction using Multiple Association Network Integration Algorithm revealed that physical interaction between these genes was 69.3%.

Conclusion

Polymorphisms of genes regulating amelogenesis can influence the susceptibility to ECC. AA genotype of rs12640848 may increase the susceptibility to ECC. Gene-based analysis revealed a significant association between multiple polymorphisms of genes regulating amelogenesis and ECC.

AMELX and ENAM Polymorphisms and Dental Caries

Introduction

The variety of the genetic factors playing role in development of dental caries calls for further research in this regard. The aim of the present study was to investigate the differences between caries-free adults and adults with dental caries in terms of polymorphism of caries-related genes (AMELX and ENAM).

Methods

The present case-control study was performed on 81 adults aged 18-24 years, 41 caries free, and 40 with a DMFT ≥ 4. A questionnaire containing background and demographic information (such as age, gender, time and type of latest dental check-ups, parent's education, oral self-care, and the place of residence in the first 12 years of life) was completed by participants at the time of examination. The blood sample was taken from each participant in the EDTA tube, and PCR was performed. Gene diversity of AMELX and ENAM genes was compared between the two groups.

Results

Regarding AMELX gene, in the caries-free group 33 (80.5%) and in the group with DMFT ≥ 4, 33 (82.5%) students had TT genotype, but this difference was insignificant. For ENAM gene, in the caries-free group 34 (82.9%) and in the group with DMFT ≥ 4, 39 (97.5%) students had TT genotype, but this difference was insignificant (P value = 0.048, CI 95%:0.02-1.27, and OR = 0.145).

Conclusion

There was no relationship between TT and TC genotypes of single nucleotide polymorphism of AMELX and ENAM gene and susceptibility to dental caries, but with increasing sample size, there may be a relationship between SNP of ENAM gene and being caries free.

Single Nucleotide Polymorphisms and Dental Fluorosis: A Systematic Review

Genetic factors contribute to susceptibility and resistance to fluoride exposure. The aim of this systematic review was to identify alleles/genotypes of single nucleotide polymorphisms (SNPs) associated with dental fluorosis (DF) and to identify them as protective or risk factors. PubMed, ScienceDirect, Cochrane Library, Scopus and Web of Science were searched for articles; the last search was performed in August 2022. Human studies that analyzed the relationship between SNPs and DF published in English were included; systematic reviews and meta-analyses were excluded. Methodological quality was graded using the Joanna Briggs Institute checklist and risk of bias was assessed using the Cochrane Collaboration's tool. Eighteen articles were included, 44% of which showed high methodological quality and data from 5,625 participants aged 6 to 75 years were analyzed. The SNPs COL1A2, ESR2, DLX1, DLX2, AMBN, TUFT1, TFIP11, miRNA17, and SOD2 were considered risk factors, and ESR1, MMP20, and ENAM were considered protective factors. In conclusion, there are alleles and genotypes of different single nucleotide polymorphisms involved in increasing or decreasing the risk of developing dental fluorosis.

FCN1 polymorphisms are not the markers of dental caries susceptibility in Polish children: A case-control study

OBJECTIVE

To examine the association of four FCN1 SNPs: -542G>A (rs10120023), -144C>A (rs10117466), +6658C>T (rs148649884), and +7895A>G (rs150625869) with dental caries in Polish children.

SUBJECTS AND METHODS

The study group consisted of 261 15-year-old Polish teenagers: 82 children with "higher" caries experience (having Decayed Missing Filled Teeth, DMFT >5) and 179 children with "lower" caries experience (having DMFT ≤5). Moreover, in additional comparison, a group of 229 children with caries experience (DMFT ≥1) was compared to a caries-free (DMFT =0) group of 32 children. Extraction of genomic DNA was performed from buccal swabs, and genotyping was performed by Real-Time PCR.

RESULTS

FCN1 SNPs +6658C>T and +7895A>G appeared to be monomorphic in our sample. The genotype, allele, or haplotype distributions in FCN1 SNPs -542G>A and -144C>A in children with "higher" caries experience did not differ significantly from those in "lower" caries experience group. Similar results with no significant differences were demonstrated for subjects with DMFT ≥1 compared to subjects with DMFT =0.

CONCLUSION

FCN1 SNPs are not the markers of dental caries susceptibility in Polish children.

Oral Microbiota-Host Interaction Mediated by Taste Receptors

Taste receptors, originally identified in taste buds, function as the periphery receptors for taste stimuli and play an important role in food choice. Cohort studies have revealed that single nucleotide polymorphisms of taste receptors such as T1R1, T1R2, T2R38 are associated with susceptibility to oral diseases like dental caries. Recent studies have demonstrated the wide expression of taste receptors in various tissues, including intestinal epithelia, respiratory tract, and gingiva, with an emerging role of participating in the interaction between mucosa surface and microorganisms via monitoring a wide range of metabolites. On the one hand, individuals with different oral microbiomes exhibited varied taste sensitivity, suggesting a potential impact of the oral microbiota composition on taste receptor function. On the other hand, animal studies and in vitro studies have uncovered that a variety of oral cells expressing taste receptors such as gingival solitary chemosensory cells, gingival epithelial cells (GECs), and gingival fibroblasts can detect bacterial signals through bitter taste receptors to trigger host innate immune responses, thus regulating oral microbial homeostasis. This review focuses on how taste receptors, particularly bitter and sweet taste receptors, mediate the oral microbiota-host interaction as well as impact the occurrence and development of oral diseases. Further studies delineating the role of taste receptors in mediating oral microbiota-host interaction will advance our knowledge in oral ecological homeostasis establishment, providing a novel paradigm and treatment target for the better management of dental infectious diseases.

DNA methylation in childhood dental caries and hypomineralization

OBJECTIVES

Epigenetic modulation of gene expression may be important in dental conditions, including dental caries and enamel hypomineralisation. The aims of this study were to assess associations between DNA methylation in cord blood leucocytes at birth, and caries experience and enamel hypomineralisation at six years of age.

METHOD

The study sample was from a birth cohort study of twins. Dental examinations at six years identified the presence/absence of (i) 'any caries' (untreated and treated caries), (ii) 'advanced caries' (untreated, advanced caries and/or past treatment) and (iii) hypomineralised second primary molars (HSPM). Genome-wide analysis of DNA methylation was performed on cord blood of 27 twin pairs (14 dizygotic and 13 monozygotic) using the Illumina Infinium MethylationEPIC BeadChip array. Differentially methylated CpGs (DMCpGs) and regions (DMRs) associated with each dental outcome were investigated, while accounting for the relatedness of twins. Results with a false discovery rate <0.05 were treated as statistically significant.

RESULTS

19 children had 'any caries', 15 had 'advanced' caries, and 18 had HSPM. No DMCpGs were associated with 'any caries', 16 and 19 DMCpGs were associated with 'advanced caries' and HSPM, respectively. DMRs were identified in association with all three outcomes. Genes implicated by these analyses included PBX1, ACAT2, LTBP3 and DDR1 which have been linked with dental tissue development in genetic studies.

CONCLUSION

This exploratory study identified differential methylation in several genes at birth associated with dental caries and HSPM at six years. Further research may provide valuable insights into aetiology of dental disease and/or reveal novel molecular-based approaches for early risk stratification.

CLINICAL SIGNIFICANCE

Epigenetic differences at birth are likely to be associated with dental health at six years and may be valuable biomarkers of early influences on dental health.

Replication of GWAS significant loci in a sub-Saharan African Cohort with early childhood caries: a pilot study

BACKGROUND

Early childhood caries (ECC) is a rapidly progressing form of dental infection and a significant public health problem, especially among socially and economically disadvantaged populations. This study aimed to assess the risk factors for ECC among a cohort of Sub-Saharan African children and to determine the role of genetics in the etiology of ECC.

METHODS

A sample of 691 children (338 with ECC, 353 without ECC, age < 6 years) was recruited from schools in Lagos, Nigeria. Socio-demographic, dental services utilization and infant dietary data were obtained with interviewer-administered questionnaire. Oral examination was conducted using the WHO oral health diagnostic criteria. Saliva samples were collected from the children for genetic analysis. Single nucleotide polymorphisms were selected from previous study for genotyping. Genetic association analyses to investigate the role of genetics in the etiology of ECC was done. Bivariate comparisons and Multivariate logistic regression analyses were conducted to assess associations between ECC and predictor variables, p < 0.05.

RESULTS

Of the 338 children with ECC, 64 (18.9%) had Severe-Early Childhood Caries (S-ECC). Children aged 48-59 months comprised the highest proportion of subjects with ECC (165; 48.8%) and S-ECC (24; 37.5%) while female subjects had higher dt (3.13 ± 2.56) and dmft values 3.27 ± 2.64. ECC was significantly more prevalent among children who were breastfed at night ≥ 12 months (OR 3.30; CI 0.39, 4.75), those with no previous dental visit (OR 1.71; CI 0.24, 2.77), those who used sweetened pacifiers (OR 1.85; CI 0.91, 3.79) and those who daily consumed sugar-sweetened drinks/snacks (OR 1.35; CI 0.09, 18.51). A suggestive increased risk for ECC (OR 1.26, p = 0. 0.0397) was observed for the genetic variant rs11239282 on chromosome 10. We also observed a suggestive reduced risk for ECC (OR 0.80, p = 0.03) for the rs131777 on chromosome 22. None of the genetic variants were significant after correction for multiple testing (Bonferroni p value p = 0.004).

CONCLUSIONS

Prolonged night-time breastfeeding, poor utilization of dental services and daily consumption of sugar were risk factors for ECC. Larger sample size is needed to confirm the results of the genetic analysis and to conduct genome wide studies in order to discover new risk loci for ECC.

Association Between the TaqI (rs731236 T>C) Gene Polymorphism and Dental Caries Risk: A Meta-analysis

Objective: This study investigated the association of the TaqI (rs731236 T>C) polymorphism in the VDR gene with dental caries.

Methods: A comprehensive literature search was performed in PubMed, Web of Science, Embase, SinoMed (the Chinese biomedical literature service system), and the Wiley Online Library. Overall comparisons and subgroup analyses based on ethnicity and the presence of dental caries in dentition were performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess associations between gene polymorphisms and the risk of dental caries.

Results: Seven articles were included in this meta-analysis. The pooled results revealed a significant association of the TaqI (rs731236 T>C) polymorphism with dental caries in the allele contrast model (C vs. T: OR = 1.24, 95% CI = 1.07–1.44, I² = 42%, p = 0.005) and in the recessive genetic model (CC vs. TT/CT: OR = 1.38, 95% CI = 1.03–1.84, I² = 0%, p = 0.03). A stratified analysis based on ethnicity revealed a significant association between the TaqI (rs731236 T>C) polymorphism and the risk of dental caries in Asians (C vs. T: OR = 1.28, 95% CI = 1.06–1.54, I² = 60%, p = 0.009). Subgroup analysis based on the presence of dental caries in dentition found a significant association of the TaqI (rs731236 T>C) polymorphism with permanent tooth caries in the allele contrast model (C vs. T: OR = 1.40, 95% CI = 1.11–1.77, I² = 76%, p = 0.005) and the recessive genetic model (CC vs. TT/CT: OR = 1.44, 95% CI = 1.03–2.00, I² = 0%, p = 0.03).

Conclusion: The results of this meta-analysis suggest that the C allele and CC genotype of the TaqI (rs731236 T>C) polymorphism in the VDR gene are associated with an increased risk of dental caries.

Association of polymorphisms in genes involved in enamel formation, taste preference and immune response with early childhood caries in Saudi pre-school children

Dental caries is primarily elicited by modifiable factors such as inadequate oral hygiene, poor dietary practices and deficient fluoride exposure. However, there is a growing body of evidence suggesting the profound influence of genetic factors in dental caries susceptibility. The present study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in ENAM (rs12640848), MMP20 (rs1784418), TAS2R38 (rs713598), and LTF (rs4547741) genes and early childhood caries (ECC) in Saudi preschool children. This case-control study enrolled 360 Saudi preschool children (262 with ECC and 98 caries-free). Data on environmental factors were collected through a questionnaire. However, caries experience and oral hygiene data were obtained during clinical examination. Buccal swab samples were collected for DNA extraction and SNPs were genotyped using PCR and DNA sequencing. Children with ECC were compared to caries free children (control), then they were categorized into two categories based on ECC severity as follows; non-severe ECC (NS-ECC), and severe-ECC (S-ECC). Association between the SNPs, ECC, NS-ECC, and S-ECC was reported as an odds ratio (OR) with a 95% confidence interval (CI). The majority of the children (72.8%) exhibited ECC (31.7% NS-ECC and 41.1% S-ECC) with mean dmft of 4.20 ± 4.05. Multivariate analyses of environmental factors showed that nocturnal feeding was a risk factor for ECC (P = 0.008). Poor oral hygiene was also a risk factor for both NS-ECC and S-ECC (ECC: P < 0.0001, NS-ECC: P = 0.032 and S-ECC: P < 0.0001). Univariate analysis showed that the AG genotype of rs1784418 of MMP20 gene was protective against ECC (OR = 0.532; 95% CI = 0.316-0.897, P = 0.018) and against NS-ECC (OR = 0.436; 95% CI = 0.238-0.798, P = 0.007). When environmental risk factors for ECC were included as covariates during multivariate analysis, AG variant in rs1784418 of MMP20 gene remained less frequent in NS-ECC cases compared to controls with borderline significance (OR = 0.542; 95% CI = 0.285-1.033, P = 0.063). Our findings concluded that MMP20 rs1784418 SNP might be associated with protection against ECC in Saudi preschool children.

Association of genetic variants in enamel-formation genes with dental caries: A meta- and gene-cluster analysis

Previous studies have reported the association between multiple genetic variants in the enamel-formation genes and the risk of dental caries with inconsistent results. We performed a systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases for studies published before March 21, 2020 and conducted meta-, gene-based and gene-cluster analysis on the association between genetic variants in the enamel-formation genes and the risk of dental caries. We identified 21 relevant publications including a total of 24 studies for analysis. The genetic variant rs17878486 in AMELX was significantly associated with dental caries risk (OR = 1.40, 95% CI: 1.02–1.93, P = 0.037). We found no significant association between the risk of dental caries with rs12640848 in ENAM (OR = 1.15, 95% CI: 0.88–1.52, P = 0.310), rs1784418 in MMP20 (OR = 1.07, 95% CI: 0.76–1.49, P = 0.702) and rs3796704 in ENAM (OR = 1.06, 95% CI: 0.96–1.17, P = 0.228). Gene-based analysis indicated that multiple genetic variants in AMELX showed joint association with the risk of dental caries (6 variants; P < 10⁻⁵), so did genetic variants in MMP13 (3 variants; P = 0.004), MMP2 (3 variants; P < 10⁻⁵), MMP20 (2 variants; P < 10⁻⁵) and MMP3 (2 variants; P < 10⁻⁵). The gene-cluster analysis indicated a significant association between the genetic variants in this enamel-formation gene cluster and the risk of dental caries (P < 10⁻⁵). The present meta-analysis revealed that genetic variant rs17878486 in AMELX was associated with dental caries, and multiple genetic variants in the enamel-formation genes jointly contributed to the risk of dental caries, supporting the role of genetic variants in the enamel-formation genes in the etiology of dental caries.

Investigation of carbonic anhydrase 6 gene polymorphism rs2274327 in relation to the oral health status and salivary composition in type 2 diabetic patients

OBJECTIVE

The aim of the present study was to investigate the oral manifestations and salivary composition in type 2 diabetics with periodontitis and to evaluate their association with CA6 gene polymorphism rs2274327.

METHODS

Oral examination was performed by a single periodontist for 300 type 2 diabetics. Whole unstimulated saliva and blood were collected. The salivary pH, buffer capacity and flow rate were later measured. Immunoglobulin A and electrolytes were assessed using an autoanalyzer. CA6 gene polymorphism rs2274327 was screened by PCR-RFLP assay. The statistical analysis was performed using the SPSS 20.0 version.

RESULTS

The salivary pH, buffer capacity and flow rate were significantly lower in the patients carrying TT genotype compared to CC and CT genotype carriers (p < .05). Furthermore, the DMFT index, OHI-s, PI, PPD and CAL were significantly higher in the subjects with TT genotype (p < .05). Carrying at least one T allele seemed to increase the risk of dental caries (OR = 2.59, p < .001), xerostomia (OR = 2.11, p=.003) and taste impairment (OR = 1.97, p < .05).

CONCLUSION

CA6 gene polymorphism rs2274327 seemed to increase the risk of developing, dental caries, periodontitis, xerostomia and taste impairment in type 2 diabetics.

Genes and SNPs in the pathway of immune response and caries risk: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to pool the data on Single Nucleotide Polymorphisms (SNPs) in immune response genes associated with dental caries. Nineteen studies were included in the review and 18 in the meta-analysis. Twenty-two SNPs were evaluated, which are linked to six different genes (MBL2, LFT, MASP2, DEFB1, FCN2 and MUC5B). Most SNPs (81.8%) are related to the possible functional impact on protein coding. The MBL2 gene was associated with caries experience in the analysis of the homozygote (OR = 2.12 CI95%[1.12-3.99]) and heterozygote (OR = 2.22 CI95%[1.44-3.44]) genotypes. The MUC5B gene was associated according to an analysis of the heterozygous genotype (OR = 1.83 CI95%[1.08-3.09]). Thus, SNPs related to immune response genes are linked to the phenotype of caries experience. Although the meta-analysis showed that the genes MBL2 and MUC5B were associated with caries, these results should be interpreted with caution due to the quality of the evidence.

Correlation of TNF-α and IL-10 gene polymorphisms with primary nephrotic syndrome

The study explored the correlations of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) gene polymorphisms with susceptibility and the condition of primary nephrotic syndrome. A total of 200 patients with primary nephrotic syndrome in Qilu hospital were collected as disease group, and 200 healthy people were selected as control group. Genomic deoxyribonucleic acids (DNAs) of nucleated cells in the peripheral blood were extracted to detect the gene polymorphisms of TNF-α (rs1799724 and rs1800629) and IL-10 (rs1800872 and rs141219090). Allele distributions at rs1799724 (P=0.003) and rs1800629 (P=0.011) of TNF-α gene and at rs1800872 (P=0.033) of IL-10 gene in disease group were different from those in control group. In the disease group, allele C frequency at rs1799724 and allele A frequency at rs1800629 of TNF-α gene and allele T frequency at rs1800872 of IL-10 gene were higher. There were differences between rs1799724 (P=0.007) and rs1800629 (P=0.002) of TNF-α gene. In addition, there was a difference in the frequency of the dominant model of TNF-α gene rs1800629 between disease group and control group (P=0.035), and the frequency of dominant model GG+GA was remarkably lower in the disease group. Additionally, TT genotype at rs1799724 of TNF-α gene was obviously related to the plasma TNF-α level (P<0.05), and the plasma TNF-α level was significantly increased in disease group. AA genotype at rs141219090 of IL-10 gene had a notable correlation with the plasma IL-10 level (P<0.05), and the plasma IL-10 level in disease group was markedly raised. Additionally, CT genotype at rs1799724 of TNF-α gene was related to the 24-h urine protein level (P=0.035), GG genotype at rs1800872 of IL-10 gene was associated with the plasma albumin level (P=0.031), and GG genotype at rs141219090 was related to the serum creatinine level (P=0.047). TNF-α and IL-10 gene polymorphisms are predominantly correlated with the susceptibility and the condition of primary nephrotic syndrome.

Lack of associations between lactoferrin (LTF) and mannose-binding lectin 2 (MBL2) gene polymorphism and dental caries susceptibility

Objective

With the development of human genomics, the genetic factors associated with dental caries have receiving increasing attention. This study was performed to evaluate the relationship between lactoferrin (LTF) and mannose-binding lectin 2 (MBL2) gene single nucleotide polymorphisms (SNPs) and dental caries susceptibility in Chinese children.

Methods

This prospective case–control study included 360 unrelated children (aged 12–15 years) who received oral health examinations and questionnaire surveys. The children were divided into two groups by counting the numbers of decayed, missing, and filled teeth (DMFT/dmft): case group (n = 162, DMFT/dmft ≥ 1) and control group (n = 198, DMFT/dmft = 0); non-invasive saliva samples were collected to extract genomic DNA. Six SNPs (rs2073495C/G, rs1042073C/T, rs10865941C/T, and rs1126477A/G in LTF; rs7096206C/G and rs7095891G/A in MBL2) were tested by mass spectrometry.

Results

The study included 360 individuals with (85 boys and 77 girls) and without a history of caries (96 boys and 102 girls). There were no statistically significant differences in alleles and genotypes among the six SNPs between the two groups.

Conclusion

There is no evidence that polymorphisms of LTF and MBL2 genes are associated with dental caries susceptibility in populations from northwest China; further confirmation is needed with larger sample sizes.

AMELX Gene Association with Dental Caries in Iranian Adults

Dental decay is a disease that is greatly affected by environmental components, but recently there have been an increasing number of documents supporting a genetic factor in the development of caries. The purpose of this study was to examine the association between dental caries and single-nucleotide polymorphisms in the AMELX gene. This research was carried out on 360 individuals of both sexes, who were referred to the dental school at the Shiraz University of Medical Sciences. In this research, individuals aged 20–65 years were divided into two groups: controls (decayed, missed, or filled teeth (DMFT) ≤ 5; n = 180) and cases (DMFT ≥ 14; n = 180). The tetra-primer ARMS-PCR technique was performed for genotyping the DNA extracted from blood cells. Analysis of the AMELX rs946252 polymorphism showed that the T allele of rs946252 was a significant protective factor against dental caries in Iranian adults (T vs. C: OR = 0.70, 95% CI: 0.49–0.98, P = 0.04). We demonstrated the significant differences in the genotype frequencies under two genetic models: overdominant (TC vs. TT + CC: OR 0.35, 95% CI 0.19–0.64, P = 0.0006) and recessive (CC vs. TC + TT: OR 2.57, 95% CI 1.39–4.76, P = 0.002). Our results show that the SNPs of the AMELX gene may be related with susceptibility to dental caries in Iranian adults.

The association between genetic variants in lactotransferrin and dental caries: a meta- and gene-based analysis

BACKGROUND

The pathogenesis of dental caries remains unclear, with increasing evidence suggesting that genetic susceptibility plays an essential role. Previous studies have reported the association between genetic polymorphisms in lactotransferrin (LTF) and the risk of dental caries with inconsistent results.

METHODS

A systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases was performed by two authors independently for papers published before December 5, 2019 on the association between genetic variants in LTF and the risk of dental caries. We adopted the subsequent inclusion criteria to assess study eligibility: 1) The studies were based on human subjects; 2) the presence of dental caries should be screened for in both the case group and the control group; and 3) genotype data on variants in LTF were available in both the case group and the control group. We calculated odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) by using random-effects models to assess the association of genetic variants in LTF with the risk of dental caries. We also performed a gene-based analysis to explore the joint association of multiple genetic variants in LTF with the risk of dental caries.

RESULTS

Our systematic literature search identified six relevant papers for analysis. We found no significant association between rs1126478 and the risk of dental caries when meta-analysing the genotype distribution between subjects with dental caries and those without dental caries (additive model: OR = 1.41; 95% CI = 0.98-2.02; P = 0.065). However, further analysis indicated that rs1126478 was associated with dental risk in subjects who had moderate or severe dental caries compared to those without dental caries (P < 0.0001). The gene-based analysis indicated that multiple genetic variants in LTF were jointly associated with the risk of dental caries (P = 0.002).

CONCLUSIONS

The present meta-analysis revealed some evidence of the association between rs1126478 and dental caries and that multiple genetic variants in LTF are jointly associated with the risk of dental caries. Our findings need to be validated by larger studies that adjust for important confounding factors for the risk of dental caries.

Polymorphism in the CAVI gene, salivary properties and dental caries

Objectives: Carbonic anhydrase (CA) VI is supposed to take part in pH or buffering capacity regulation, which can influence the caries risk of an individual. Its expression in the saliva can be modified by single nucleotide polymorphism (SNP). The aim was to investigate SNP in the CA VI gene in relation to active dental caries and physiochemical properties of saliva.Materials and methods: One hundred and thirty participants aged 11-16 years were involved. Clinical examinations were carried out using standardized WHO criteria, DMFT/DMFS and white spot lesions score was evaluated. Saliva samples were examined for salivary properties and CA VI concentration. DNA evaluated in the investigation was extracted from the buccal smear. Three SNP within CAVI gene (rs2274327; rs2274328; rs2274333) were selected and genotyping was performed.Results: In the active caries group, the mean CAVI concentration was significantly lower than in caries free group (p = .014). No association between increased or decreased risk of caries and analysed SNPs was found. There were some significant relations concerning SNPs and salivary buffer capacity and flow rate in rs2274327 and rs2274328.Conclusions: Polymorphism in the CAVI gene can affect salivary properties but there is no direct connection with dental caries.

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.

MMP13 Contributes to Dental Caries Associated with Developmental Defects of Enamel

The aim of this study was to investigate the association between genetic polymorphisms in MMP8, MMP13, and MMP20 with caries experience and developmental defects of enamel (DDE) in children from the Amazon region of Brazil. Den tal caries and DDE data were collected through clinical examination from 216 children. Genomic DNA was extracted from saliva, and genotyping of selected polymorphisms in MMP8 (rs17099443 and rs3765620), MMP13 (rs478927 and rs2252070), and MMP20 (rs1784418) was performed using TaqMan chemistry and endpoint analysis. χ2 or Fisher's exact tests were used to compare allele and genotype distributions between children with caries experience and caries-free children and between DDE-affected and -unaffected children with an established alpha of 5%. The polymorphism rs478927 in MMP13 was associated with caries experience and DDE (p < 0.05). The analysis performed comparing children with both conditions (caries experience plus DDE) and children with neither of the conditions (caries-free chil dren without DDE) demonstrated that children carrying the MMP13 rs478927 TT genotype were more likely to have concomitant occurrence of these two conditions (OR = 5.8, 95% CI 2.1-15.8; p = 0.0003). In conclusion, the genetic polymorphism rs478927 in MMP13 was associated with caries experience and DDE.

Are the mutans streptococci still considered relevant to understanding the microbial etiology of dental caries?

The mutans streptococci were once the primary focus of research dedicated to understanding the etiology of dental caries. That focus has now shifted to an emphasis on the ecological balances and complexities within the entirety of the plaque microbiome. Within that framework there are considerable differences of opinion regarding the importance and relative contributions of the mutans streptococci. This article explores the basis for the various viewpoints, the limitations of current knowledge, and the confounders that make it difficult to arrive at a consensus.

Exploring the genomic basis of early childhood caries: a pilot study

OBJECTIVE

A genetic component in early childhood caries (ECC) is theorized, but no genome-wide investigations of ECC have been conducted. This pilot study is part of a long-term research program aimed to: (1) determine the proportion of ECC variance attributable to the human genome and (2) identify ECC-associated genetic loci.

METHODS

The study's community-based sample comprised 212 children (mean age=39 months; range = 30-52 months; males = 55%; Hispanic/Latino = 35%, African-American = 32%; American Academy of Pediatric Dentistry definition of ECC prevalence = 38%). Approximately 2.4 million single nucleotide polymorphisms (SNPs) were genotyped using DNA purified from saliva. A P < 5 × 10^-8 criterion was used for genome-wide significance. SNPs with P < 5 × 10^-5 were followed-up in three independent cohorts of 921 preschool-age children with similar ECC prevalence.

RESULTS

SNPs with minor allele frequency ≥5% explained 52% (standard error = 54%) of ECC variance (one-sided P = 0.03). Unsurprisingly, given the pilot's small sample size, no genome-wide significant associations were found. An intergenic locus on 4q32 (rs4690994) displayed the strongest association with ECC [P = 2.3 × 10^-6 ; odds ratio (OR) = 3.5; 95% confidence interval (CI) = 2.1-5.9]. Thirteen loci with suggestive associations were followed-up - none showed evidence of association in the replication samples.

CONCLUSION

This study's findings support a heritable component of ECC and demonstrate the feasibility of conducting genomics studies among preschool-age children.