Talon Cusp Associates With MMP2 in a Cohort of Individuals Born With Oral Clefts

Erosive Tooth Wear, Wine Intake, and Genetic Variation in COMT and MMP2

INTRODUCTION

Erosive tooth wear (ETW) is a multifactorial condition of increasing prevalence in the younger population. This study aimed to explore the association between different ETW phenotypes with MMP2 and COMT single-nucleotide variants and selected environmental factors.

METHODS

Saliva samples, erosive wear, and dental caries experience data and dietary/behavioral information from 16- to 18-year-old patients (n = 747) were used. Genotypes were obtained, and phenotypes were further analyzed considering diet and behavioral data, using logistic regression as implemented in PLINK, with an alpha of 0.05.

RESULTS

When comparing individuals' ETW-free with those with mild ETW, an association was found with COMT rs6269 (p = 0.02). The comparison between ETW-free individuals with individuals with severe ETW also showed an association with COMT rs6269 under the recessive model (p = 0.03). Logistic regression showed that in the presence of less common alleles of MMP2 rs9923304 and COMT rs6269, ETW was more likely to occur when individuals drank wine. The GG genotype of COMT rs6269 was associated with the presence of lower (p = 0.02) and higher (p = 0.02) caries experience when individuals with ETW only in enamel were compared with individuals with ETW involving dentin.

CONCLUSION

The results support a role of genes in ETW, with wine consumption being identified as a significant modulator, suggesting that gene-environment interactions may contribute to the development of ETW.

Association of MMP2 and MMP9 gene polymorphisms with nonsyndromic cleft lip/palate in an Iranian population

Background

Cleft lip/palate (CL/P) is a prevalent congenital disorder. Matrix metalloproteinases (MMPs) play a role in palatogenesis and have been proposed to be associated with nonsyndromic CL/P development. This study aimed to examine the association of MMP2 (rs243866) and MMP9 (rs3918242) gene polymorphism with nonsyndromic CL/P in an Iranian population.

Methods

Blood samples were collected from 120 nonsyndromic CL/P patients and 140 healthy newborns in this case-control study. DNA extraction was performed by the salting-out method, and the samples underwent polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), using Pag and SphI enzymes, for genotyping MMP2 and MMP9 gene polymorphisms. Statistical analysis was performed with SPSS 11.5. Univariate and multivariate logistic regression models were used to calculate the odds ratios and 95% confidence intervals (CIs). The level of statistical significance was set at P<0.05.

Results

No significant association was found between MMP2 gene polymorphism and nonsyndromic CL/P. However, the MMP9 gene polymorphism had a significant association with nonsyndromic CL/P, with a higher prevalence of the T allele and TT genotype in the case group than the control group.

Conclusion

This study indicated a potential link between MMP9 gene polymorphism and nonsyndromic CL/P in an Iranian population. Future investigations with greater sample diversity and larger sample sizes are required to obtain more comprehensive and robust evidence. In-depth analyses and studies involving different ethnic groups can further enhance our understanding of the genetic underpinnings of CL/P.

Evaluation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human cases with orofacial clefts: A systematic review

INTRODUCTION

The interaction between several cell populations or many genes and the coordination of multiple signal transmission pathways can lead to defects such as orofacial clefts (OFCs). Herein, a systematic review was designed to evaluate a group of important biomarkers (matrix metalloproteinases [MMPs] and tissue inhibitors of metalloproteinases [TIMPs]) in human cases with OFCs.

MATERIAL AND METHODS

Four databases including PubMed, Scopus, Web of Science, and Cochrane Library databases were searched until March 10, 2023, without any restriction. STRING, the protein-protein interaction (PPI) network software, was applied to investigate the functional interactions among the examined genes. The effect sizes including odds ratio (OR) dealing with a 95% confidence interval (CI), were extracted by the Comprehensive Meta-Analysis version 2.0 (CMA 2.0) software.

RESULTS

Thirty-one articles were entered into the systematic review that four articles were analyzed in the meta-analysis. Single studies reported that several polymorphisms of MMPs (rs243865, rs9923304, rs17576, rs6094237, rs7119194, and rs7188573); and TIMPs (rs8179096, rs7502916, rs4789936, rs6501266, rs7211674, rs7212662, and rs242082) had an association with OFC risk. There was no significant difference for MMP-3 rs3025058 polymorphism in allelic (OR: 0.832; P=0.490), dominant (OR: 1.177; P=0.873), and recessive (OR: 0.363; P=0.433) models and MMP-9 rs17576 polymorphism in an allelic model (OR: 0.885; P=0.107) between the OFC cases and the controls. Based on immunohistochemistry reports, three MMPs (MMP-2, MMP-8, and MMP-9) and TIMP-2 had significant correlations with several other biomarkers in OFC cases.

CONCLUSIONS

MMPs and TIMPs can impact the tissue and cells affected by OFCs and the process of apoptosis. The interaction between some biomarkers with MMPs and TIMPs (e.g., TGFb1) in OFCs can be interesting for future research.

A Need for Updating the Research Agenda for Cleft Lip and Palate and Extending the Cleft Team Model to Dental Medicine

Care for individuals born with cleft lip and palate is done by a team approach, including dental medicine. However, oral health is not integrated in other situations that affect overall health. This perspective essay makes the case for a universal team approach, having dental medicine integrated regardless of the overall health issue, much like how cleft lip and palate is managed. Furthermore, future research agenda on the etiology of cleft lip and palate in particular will need to be adjusted for a major roadblock: the lack of more sophisticated clinical descriptions for the cases ascertained at birth.

Maxillary incisor enamel defects in individuals born with cleft lip/palate

Cleft lip with or without cleft palate (CLP) is considered the most frequent congenital malformations of the head and neck, with cleft individuals exhibiting more chances of presenting abnormalities such as developmental defects of enamel (DDE). Matrix metallopeptidase 2 (MMP2) is a membrane-bound protein with collagen-degrading ability and has important roles in tooth formation and mineralization. The aim of this study was to evaluate the frequency, location, severity and extent of DDE found in the maxillary incisors for groups of individuals born with CLP, as well as understanding their relationship with the cleft side. Besides, this study addresses the hypothesis that DDE can be influenced by variation in the MMP2 genes (rs9923304). Individual samples, clinical history, intraoral photographs and panoramic radiographs were obtained from 233 patients under treatment at the Cleft Lip and Palate Service of the University Hospital Lauro Wanderley at the Federal University of Paraíba. Digital images were examined by the same evaluator using the Classification of Defects According to the Modified DDE Index, and then loaded into the Image Tool software, where two measurements were made: total area of the buccal surface (SA) and the area of the DDE (DA), obtaining the percentage of the surface area affected (%SAD) (ICC = 0.99). Genomic DNA was extracted from saliva samples from 124 participants. Genotyping was carried out using TaqMan chemistry for one marker in MMP2 (rs9923304). Statistical analyses were performed by The Jamovi Project software. The Shapiro-Wilk test was applied, followed by the Student's t-test and the Mann-Whitney test. Chi-square and Fisher's exact tests, and odds ratio (OR) with 95% confidence interval (CI) calculations were used to determine Hardy-Weinberg equilibrium and statistically significant differences with an alpha of 0.05. No significant differences in the prevalence and extent of enamel defects were found between male and female individuals born with CLP (p = 0.058256). The frequency of individuals presenting teeth with DDE, in relation to the cleft and non-cleft side, was statistically different (p <0.001; OR = 7.15, CI: 4.674> 7.151> 10.942). However, the averages of %SAD were similar (p = 0.18). The highest means of the %SAD were found in individuals with bilateral cleft lip with or without cleft palate (BCLP) when compared to individuals with unilateral cleft lip with or without cleft palate (UCLP), for the teeth inside (IA) and outside the cleft area (OA) (p <0.001). Regardless of the cleft side, individuals with BCLP were 7.85 times more likely to have more than one third of the tooth surface affected, showing more frequently defects in the three thirds (OA: p <0.001) (IA: p = 0.03), as well as a higher frequency of more than one type of defect (OA: p = 0.000358) (IA: p = 0.008016), whereas in UCLP, defects were isolated and restricted to only one third, more frequently, the incisal third (OA: p = 0.009) (IA: p = 0.001), with greater frequency of milder defects, such as demarcated (p = 0.02) and diffuse (p = 0.008) opacities. A higher frequency of the T allele, less common, was observed in the group of CLP individuals who had all the affected teeth or at least two teeth with %SAD greater than 20% (p = 0.019843). Our results suggest that MMP2 may have a role in the cases that presented DDE and genotyping rs9923304 could serve as the basis for a genomic approach to define risks for individuals born with CLP. Frequency and severity of DDE is strongly related to the CLP phenotype, since the highest values were found for BCLP. However, the extent of the DDE is independent of its relationship with the side of the cleft.