Single-Nucleotide Polymorphisms in MMP3, TIMP1, and MTR Genes are Associated With Delayed Deciduous Tooth Eruption.

To analyze whether the single-nucleotide polymorphisms (SNPs) in Matrix metalloproteinases 2, 3, and 9 (MMP2, MMP3, and MMP9), Tissue Inhibitor of Metalloproteinases 1 and 2 (TIMP1 and TIMP2), methionine synthase (MTR) and methionine synthase reductase (MTRR) influence delayed deciduous tooth eruption (DDTE). This cross-sectional study included 1060 biologic unrelated children (aged between 6 and 36 months) of both sexes, selected from 25 public schools in Nova Friburgo, Rio de Janeiro, Brazil. Oral examination was conducted and DDTE was defined by the absence of gingival eruption according to a chronology based on the Brazilian population. Genotyping of selected SNPs (rs243847, rs52261, rs17576, rs4898, rs7501477, rs1805087, and rs1801394) was performed using TaqMan real-time PCR with genomic DNA extracted from buccal cells. The association between genotypes and DDTE was evaluated using univariate and multivariate analyses (p < 0.05). A total of 224 children and caregivers were included after the eligibility criteria. The heterozygous genotype for the SNPs MTR (rs11805087) was associated with DDTE in both the univariate (p = 0.004) and multivariate (p < 0.001) codominant models, as well as in the univariate (p = 0.010) and multivariate (p = 0.001) recessive models. TIMP1 (rs4898) and MMP3 (rs522616) were associated with DDTE only in the univariate model (p < 0.05). The SNPs in MTR (rs11805087), MMP3 (rs522616) and TIMP (rs4898) genes are associated with DDTE. The factors affecting the chronology of deciduous tooth eruption has been insufficiently studied. This article brings novel knowledge regarding the role of genetics polymorphisms on timing variation of deciduous tooth eruption. Understanding the factors that impact tooth eruption is crucial for the fields of pediatric dentistry and orthodontics.