Genetic Polymorphisms in ACTN3 Contribute to the Etiology of Bruxism in Children.

Objective: Bruxism is a condition defined as a masticatory muscle activity with an unexplored genetic background. The aim of this study was to evaluate the association between genetic polymorphisms in ACTN3 and bruxism. Study design: A total of 151 biological-unrelated children, aged 7-12 years were included in a case control ratio of 1:1.5. The data collection was performed during interview and clinical examination. Saliva samples were collected from all children and 3 genetic polymorphisms in the ACTN3 (rs678397, rs1671064 and rs1815739) were selected for genotyping using real time PCR. Pearson chisquare calculation was used to assess Hardy-Weinberg equilibrium and to evaluate the association between genotypes and alleles frequencies for each genetic polymorphism in the co-dominant and recessive models. An alpha of 5% was used. Results: The genetic polymorphisms rs678397, rs1671064 and rs1815739 were associated with bruxism in the co-dominate model and in the recessive model (p<0.05). Allele distribution was also associated with bruxism for the polymorphisms rs678397 and rs1671064 (p<0.05). Conclusion: The genetic polymorphisms rs678397, rs1671064 and rs1815739 in ACTN3 are associated with bruxism and can contribute to the etiology of this condition in children.