ABSTRACT
OBJECTIVES: Temporomandibular disorder (TMD) is considered a functional disorder with multifactorial aspects. The goal of this study was to investigate if genetic polymorphisms in the COL2A1 gene could be associated with TMD in adolescents. STUDY DESIGN: The case group (TMD-affected) included individuals diagnosed with any of the following TMD subgroups according to the RDC/TMD criteria: myofascial pain, disc displacements and arthralgia. Genomic DNA for molecular analysis was extracted from buccal cells and genetic polymorphisms in COL2A1 were genotyped by real time polymerase chain reactions using the TaqMan assay. Data were analyzed using the Epi Info 3.5.7 and Stata software. RESULTS: 249 subjects were included in this study (148 subjects "affected" by TMD). There were no significant differences between the affected and unaffected individual (p>0.05), for TMD, arthralgia and myofascial pain however, rs2276454 was borderline in the genotype distribution (p=0.07) and was associated with disc displacement (p=0.03) in the allelic distribution. Recessive model showed significant differences between groups for with disc displacement (p=0.02). CONCLUSIONS: Genetic polymorphisms in COL2A1 are not associated with myofascial pain, arthralgia or TMD in adolescents but this study provides evidence that rs2276454 is involved in the disc displacement of the temporomandibular joint.
Subject(s)
Joint Dislocations , Polymorphism, Genetic , Temporomandibular Joint Disorders , Temporomandibular Joint Dysfunction Syndrome , Adolescent , Arthralgia , Collagen Type II/genetics , Facial Pain , Humans , Mouth Mucosa , Temporomandibular Joint , Temporomandibular Joint Disorders/geneticsABSTRACT
BACKGROUND: Temporomandibular disorder (TMD) is a multifactorial condition that combines environmental and genetic factors and its prevalence increases during adolescence. AIM: To investigate the association between TMD and genetic polymorphisms in the DRD2 and ANKK1 in a population of Brazilian adolescents. DESIGN: The TMD group included adolescents diagnosed with any of the following TMD subgroups according to the RDC/TMD criteria: myofascial pain, arthralgia and disc displacement and painful TMD. Genomic DNA for molecular analysis was extracted from buccal cells, and genetic polymorphism rs6275 in DRD2 and rs1800497 in ANKK1 were genotyped by real-time polymerase chain reactions using the TaqMan assay. Data were analysed using the Epi Info 3.5.7 and Stata software, with significance level of 0.05. RESULTS: Two hundred fifty-one individuals were included in this study, 148 subjects presented TMD. For disc displacement, the genetic polymorphisms rs6275 was associated in a recessive model (P = 0.04), whereas the rs6276 and rs1800497 presented only a borderline association in a recessive and dominant models, respectively (P = 0.07 and P = 0.06). CONCLUSION: The genetic polymorphism rs6275 in DRD2 was associated with disc displacement in Brazilian adolescents.
