Molecular genetics and epigenetics of temporomandibular disorder

Abstract

Temporomandibular joint (TMJ) has an important role in stomatognathic system. Its role during function is facilitated from rotation and translation movement. Any deviation from TMJ normal anatomy and movement could lead into either clicking, crepitus, or pain in preauricular area. These sign and symptoms, which are widely referred as TMJ Temporomandibular joint disorder (TMD), extremely common in world population. Several genes have been identified contribute in susceptibility towards TMD. Genetic polymorphism are a form of gene sequences variance that is found in more than 1% of world population. Epigenetics is an interaction between internal and external environments that leads to a change in chromatin structures that switches the gene expression on and off. There are several factors that posibly affect the genetic polymorphisms in TMD such as; serotonin, cathecolamine, estrogen, folate, human leukocyte antigen (HLA), extracellular matrix, transcription factors, transforming growth factor beta (TGFβ), epithelial growth factor, β-catenin, and discoidin. Epigenetic mechanisms such as DNA methylation, histone modification, and microRNA are found in chondrocyte of TMD patients. In a temporomandibular joint, miRNA-140 controls bone homeostasis especially on the articular remodeling. Genetic molecular and epigenetic study will benefit in diagnosis and treatment of TMD patient. The aim of this paper is author want to inform about molecular genetics and epigenetics of TMD.