Matrix Metalloproteinase-2 Gene Polymorphisms Decrease Chances of Muscle TMD Development in Brazilian Population

Abstract

Introduction: Muscular Temporomandibular disorders or masticatory disorders are characterized by orofacial pain and functional limitations associated with oral dysfunctions, emotional changes and/or genetic factors. Matrix Metalloproteinases (MMPs) are proteolytic enzymes that constitute the extracellular matrix and play an important role in the skeletal muscle adaptation. Objectives: To evaluate the association between polymorphisms in the Matrix Metaloprotease-2 (MMP2) gene and the presence of muscular disorders. Methods: RDC/TMD questionnaire was applied for clinical diagnosis of Temporomandibular Disorders (TMD) in the study sample and three diagnosis groups were formed: control group (n=154), muscular TMD (n=122) and joint TMD (n=49). Genomic DNA was obtained from saliva samples and six single nucleotide polymorphisms in the MMP2 gene were selected. Results: A tendency of association between the presence of the CT genotype (rs243865) and the absence of muscular TMD was observed when compared to the control group (p=0.05). There was a significant prevalence of the polymorphic CT+TT (rs243865) genotypes in the control group (p=0.04) compared to the muscular TMD group (p=0.05). Confirming these results, TCCACC MMP2 haplotype showed higher association (p=0.01) with protection against muscular TMD. Conclusion: Polymorphism in the MMP2 gene (rs243865) is related to protection against muscular TMD.