Temporomandibular joint (TMJ) degeneration is a frequent cause of orofacial pain. Matrix metalloproteinases (MMPs) degrade extracellular matrix components and play an important role in TMJ degeneration. We investigated the frequency of the MMP1 1G/2G polymorphism (rs1799750), the MMP3 5A/6A polymorphism (rs3025058), and the MMP9 C/T polymorphism (rs3918242) in individuals with TMJ degeneration, in order to analyze the association of polymorphisms in these genes with TMJ degeneration. The population studied comprised 117 healthy controls and 115 individuals diagnosed with TMJ degeneration upon examination of magnetic resonance imaging (MRI) and computed tomography (CT) images. Genotypes were determined using PCR restriction fragment length polymorphism (RFLP). Logistic regression analyses revealed an association between the MMP1 2G/2G genotype and degeneration; in contrast, there was no association between either the MMP3 or the MMP9 genotype and degeneration. Our results may indicate a role for the MMP1 polymorphism in TMJ degeneration.1191-6