Association between genetic polymorphisms in the melatonin receptor type 1 A gene and sleep bruxism.

OBJECTIVE: This study evaluated whether single nucleotide polymorphisms in the melatonin receptor type 1 A gene are associated with sleep bruxism in a Brazilian population. DESIGN: Individuals with suspected sleep-related problems were evaluated using polysomnography, following the recommendations proposed by the American Academy of Sleep Medicine and the Research Diagnostic Criteria for Temporomandibular Disorders. Deoxyribonucleic acid (DNA) samples were collected, and three single nucleotide polymorphisms in the melatonin receptor type 1 A gene (rs13140012, rs6553010, and rs6847693) were selected and genotyped using real-time polymerase chain reaction (RT-PCR). Chi-square and odds ratio tests were used to analyze genotypes and alleles individually, while using the plink software for haplotypes. A confidence interval of 95% was considered, and statistical significance was set at p < 0.05. RESULTS: This study included 48 individuals aged between 21 and 80 years, with 27 males and 21 females. From this sample, 17 individuals were diagnosed with sleep bruxism and 31 without bruxism. No associations were found between sleep bruxism and single nucleotide polymorphisms in either the genotypic, allelic, dominant, or recessive models (p > 0.05). Haplotype genetic analysis also did not reveal any association between single nucleotide polymorphisms and sleep bruxism (p > 0.05). CONCLUSION: The genetic polymorphisms rs6553010, rs13140012, and rs6847693 were not associated with sleep bruxism in the studied population.