Association of single nucleotide polymorphisms of the COMT gene and bruxism: a systematic review

Abstract

This study aimed to investigate if single nucleotide polymorphisms (SNP) of the Catechol-O-methyltransferase (COMT) gene are associated with bruxism, an oral habit of voluntary or involuntary movement of the mandible, characterised by jaw clenching and teeth grinding. Along with investigating the methods used to diagnose bruxism. Materials and methods: A search of the PubMed, Scopus and Medline databases were conducted from 2012 until January 2023. For articles including SNPs of the COMT gene with a minimum of 5 subjects, including a bruxism and control group. Results: The four studies chosen were non-randomised observational studies investigating the association of certain single nucleotide polymorphism of genes, including COMT and its association to bruxism patients having sleep tooth clenching in children carrying the GG genotype (p=0.003) and the AA genotype(p=0.001). There was found to be an association in the univariate regression analysis which was statistically significant between patients with the SNP rs6929 of the COMT gene in the AG genotype and bruxism in adults (p=0.003), All The other SNPs studied of COMT and its associated genotypes did not show any significant statistical correlation to the presence of bruxism(p>0.05),).The diagnosis of bruxism was done by overnight studies using conventional polysomnographic testing equipment. For children, patients’ parents were questioned, alongside clinical examinations to select the sample and diagnose bruxism.