Bruno D'Aurea Furquim1, Lívia Maria Sales Pinto Flamengui2, Carlos Eduardo Palanch Repeke3, Franco Cavalla4, Gustavo Pompermaier Garlet5, Paulo César Rodrigues Conti6. 1. Associate professor, Department of Orthodontics, University of North Paraná, Londrina, Paraná, Brazil. Electronic address: brunofurquim@hotmail.com. 2. Private practice, Fortaleza, Ceará, Brazil. 3. Associate professor, Department of Dentistry, Federal University of Sergipe, Lagarto, Sergipe, Brazil. 4. Assistant professor, Conservative Dentistry Department, University of Chile, Santiago, Chile. 5. Editor-in-chief, Journal of Applied Oral Sciences; associate professor and head, Department of Biological Sciences, School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil. 6. Associate professor, Department of Prosthodontics, School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
Abstract
INTRODUCTION: Tumor necrosis factor alpha (TNF-α) levels are significantly upregulated in the synovial fluid of patients with temporomandibular joint disorder (TMD). The TNF-α influences pain generation and maintenance. Therefore, the aim of this study was to investigate the influence of single nucleotide polymorphism TNFA-308 (rs1800629) on TMD risk and on the pressure pain threshold. METHODS: The genotypic and allelic frequencies of candidate single nucleotide polymorphisms were compared among 152 TMD patients and 91 sex- and age-matched healthy subjects in the control group using the real-time polymerase chain reaction technique. The pressure pain threshold in the temporomandibular joint, anterior fascicle of the temporal muscle, masseter muscle, and Achilles tendon were recorded with an algometer. After the pressure test, all participants received a complete physical examination, including masticatory muscle evaluation, temporomandibular joint palpation, and assessment of mandibular range of motion. RESULTS: The TNFA-308 polymorphism is positively associated with TMD. Subjects with TMD had a 2.87 (95% confidence interval, 1.256-6.569) times greater chance of having the GA genotype than did the control group. Rare A-allele homozygotes demonstrated decreased pain sensitivity for the temporomandibular joint and anterior fascicle of the temporal muscle in the pressure pain threshold test compared with ancestral allele homozygotes. CONCLUSIONS: This study presents an unprecedented association between the TNFA-308 (rs1800629) polymorphism and TMD. Future studies are needed to enlighten the association between TNFA-308 G/A single nucleotide polymorphism and mechanical pain sensitivity.
INTRODUCTION:Tumor necrosis factor alpha (TNF-α) levels are significantly upregulated in the synovial fluid of patients with temporomandibular joint disorder (TMD). The TNF-α influences pain generation and maintenance. Therefore, the aim of this study was to investigate the influence of single nucleotide polymorphism TNFA-308 (rs1800629) on TMD risk and on the pressure pain threshold. METHODS: The genotypic and allelic frequencies of candidate single nucleotide polymorphisms were compared among 152 TMDpatients and 91 sex- and age-matched healthy subjects in the control group using the real-time polymerase chain reaction technique. The pressure pain threshold in the temporomandibular joint, anterior fascicle of the temporal muscle, masseter muscle, and Achilles tendon were recorded with an algometer. After the pressure test, all participants received a complete physical examination, including masticatory muscle evaluation, temporomandibular joint palpation, and assessment of mandibular range of motion. RESULTS: The TNFA-308 polymorphism is positively associated with TMD. Subjects with TMD had a 2.87 (95% confidence interval, 1.256-6.569) times greater chance of having the GA genotype than did the control group. Rare A-allele homozygotes demonstrated decreased pain sensitivity for the temporomandibular joint and anterior fascicle of the temporal muscle in the pressure pain threshold test compared with ancestral allele homozygotes. CONCLUSIONS: This study presents an unprecedented association between the TNFA-308 (rs1800629) polymorphism and TMD. Future studies are needed to enlighten the association between TNFA-308 G/A single nucleotide polymorphism and mechanical pain sensitivity.