title: Role of Thr399Ile and Asp299Gly polymorphisms of toll-like receptor-4 gene in acute dental abscess.
abstract: BACKGROUND
  Apical Periodontitis (AP) is an inflammatory disease that affects the tissues surrounding the root end of a tooth. The disease which is caused by endodontic infections presents in different clinical ways including development of an acute abscess. Recent studies have provided information suggesting role of a multitude of factors in pathogenesis of acute apical abscess (AAA). In this case-control study, our goal was to evaluate the frequency and potential role of two common polymorphisms of toll like receptor-4 (TLR-4) gene; Thr399Ile (1196 C>T) and Asp299Gly (+896 A>G), in 50 patients with AAA as cases and 50 patients with asymptomatic apical periodontitis (AAP) as controls.
  
  
  METHODS
  Saliva sample containing mucosal epithelial cells was used for DNA extraction. Polymorphisms were detected by Tetra-ARMS (Amplification Refractory Mutation System) PCR method. Statistical analyses were carried out in SPSS 21 software.
  
  
  RESULTS
  Homozygous wild type (CC) and heterozygous (CT) genotypes of Thr399Ile polymorphism were detected in 84% and 16% of AAA patients respectively. In controls, respective ratios were 94% (CC) and 6% (CT). Observed difference was not statistically significant (P>0.05) for distribution of these genotypes. The mutant homozygous (TT) genotype of this polymorphism was identified in neither of the participants. Overall, T allele frequency was obtained 8% in AAA and 3% in AAP (OR=2.6, 95% CI; 0. 6-10.6,p>0.05). For Asp299Gly polymorphism, no individual was detected with the mutant allele in case or control groups.
  
  
  CONCLUSIONS
  Our results indicated a possible role for Thr399Ile polymorphism in acute presentations of abscess in AAA. However, the impact of this polymorphism needs to be more assessed in future studies.Key words:Genetic polymorphism, periapical abscess, periapical periodontitis, toll-like receptor 4.
authors.affiliation: Genetics of Non-Communicable Disease Research Center & Department of Genetics, Faculty of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Miri-Moghaddam
authors.affiliation: Oral and Dental Diseases Research Center, Department of Endodontics, Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Narges
authors.initials: N
authors.lastname: Farhad-Mollashahi
authors.affiliation: Faculty of Dentistry, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Elnaz
authors.initials: E
authors.lastname: Baghaee
authors.affiliation: Faculty of Allied Medical Sciences, Zabol University of Medical Sciences, Zabol, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Bazi
authors.affiliation: Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Garme