Possible association of temporomandibular joint pain and dysfunction with a polymorphism in the serotonin transporter gene.

The purpose of this study was to evaluate the relationship between temporomandibular joint pain and dysfunction and serotonin transporter (5-HTT) gene polymorphism. Forty-eight patients with temporomandibular joint pain and 111 healthy control subjects were examined. The results for the patients and control subjects were not significantly different (P >.05). The analysis of genotype distribution (homozygous for STin 2.10 genotypes of the variable-number tandem-repeat polymorphism) showed significant differences between the patients and control subjects (P =.003). ST 2.10 allele was more frequent in the patients with temporomandibular joint pain and dysfunction. In the control group, however, STin 2.12/12 genotype was significantly higher (P =.017). In the patients who were homozygous or heterozygous for variable-number tandem-repeat variants of 5-HTT STin 2.12 copies, the average scores of somatization and anger were significantly higher than those who were homozygous for STin 2.10 variant (P <.05). The patients who were homozygous for STin 2.10 genotype were also homozygous for "L" genotype (P =.019). However, this was not the condition in the control subjects. This study does not provide evidence to support the involvement of 5-HTT gene-linked polymorphic region in temporomandibular joint pain and dysfunction. Our findings indicated that only the presence of the homozygous STin 2.10 genotype of variable-number tandem-repeat is likely to play a substantial role in the genetic predisposition to temporomandibular joint pain and dysfunction and that the STin 2.12/12 genotype may have a protective role against temporomandibular joint pain and dysfunction.     

转化生长因子β1基因-509位点多态性与重度慢性牙周炎易感性的关系

目的 探讨转化生长因子β1(transforming growth factor beta-1,TGF-β1)基因-509位点多态性与重度慢性牙周炎易感性的关系,以期从基因水平探讨牙周炎发病的遗传学机制.方法 用聚合酶链反应-限制性片段长度多态性方法检测102例重度慢性牙周炎患者(牙周炎组)和102名健康对照者(健康对照组)的TGF-β1基因-509位点,比较两组间此位点基因型分布和等位基因频率的差异.结果 TGF-β1基因-509位点CC、CT、TT基因型在牙周炎组和健康对照组的分布频率分别为44.1%(45/102)、47.1%(48/102)、8.8%(9/102)和29.4%(30/102)、51.0%(52/102)、19.6%(20/102),两组人群基因型分布频率差异有统计学意义(P＜0.05);等位基因C、T在牙周炎组和健康对照组分布频率分别为67.6%(138/204)、32.4%(66/204)和54.9%(112/204)、45.1%(92/204),两组人群的等位基因分布频率差异亦有统计学意义(P＜0.05),C等位基因携带者患重度慢性牙周炎的风险是T等位基因的1.718倍(OR=1.718,95%CI:1.148～2.569).结论 TGF-β1基因-509位点多态性与重度慢性牙周炎的发病具有相关性,C等位基因可能是重度慢性牙周炎的遗传易感基因.     

Effect of tumor necrosis factor alpha (TNF-α) -308 and -1031 gene polymorphisms on periodontitis among Saudi subjects

ObjectivesPeriodontitis is an infectious disorder that leads to irreversible loss of the surrounding attachment and bone destruction. Genetic polymorphism of cytokines has been suggested to play a role in periodontitis. This case-control study aimed to investigate the relationship between periodontitis and two single nucleotide polymorphisms (SNPs): rs1800629 (-308 G/A) and rs1799964 (-1031 T/C), in the TNF-α gene promoter area.Materials and methodsPeripheral blood was used to prepare genomic DNA from 60 subjects with stage II to stage III periodontitis, as along with 65 control subjects. Polymerase chain reaction and restriction endonuclease digestion were used to genotype TNF-α SNPs.ResultsThe distribution of both genotypes and alleles of TNF-α (-308 G/A) polymorphism did not vary between periodontitis subjects and the controls (P > 0.05). However, the CT genotype and C allele of the TNF-α (-1031 T/C) polymorphism were observed more frequently in the periodontitis subjects than in the controls, while the TT genotype and the T allele were more predominant in the control subjects than in the periodontitis patients (OR: 3.149; 95% CI: 1.494–6.639; P = 0.002 and OR: 2.933; 95% CI: 1.413–6.090; P = 0.003, sequentially).ConclusionThe TNF-α (-308 G/A) polymorphism potentially has no correlation with periodontitis susceptibility, whereas the TNF-α (-1031) CT genotype and C allele might be related to periodontitis among Saudi subjects.     

IL-1B＋3954C/T和IL-1B-511C/T基因多态性和种植体周围炎的相关性研究

目的：探讨研究种白介素1（IL-1）基因＋3954和-511位点单核酸多态性和种植体周围炎的关系以及临床意义。方法：采用病例对照实验设计,选取种植体炎患者以及对照组各50名,应用聚合酶链反应—限制性内切酶片段长度多态性基因分析方法研究两组IL-1B基因＋3954位点和-511位点基因型和等位基因分布特点,并探讨其与种植体周围炎的相关性。结果：IL-1B基因＋3954位点CC、CT基因型检出率为93%和7%,无TT基因型,两种基因型和C、T等位基因频率在组间分布差异无统计学意义（P〉0.05）;IL-1B基因-511位点主要以CT为主,检出率为58%,CC、CT基因型检出率都为21%。结论：排除吸烟,牙周炎病史等影响因素后,IL-1B基因＋3954位点和-511位点的多态性与种植体周围炎炎的易感性无关。     

5 polymorphisms in the transforming growth factor-beta 1 gene (TGF-beta 1) in adult periodontitis

OBJECTIVES: Transforming growth factor-beta (TGF-beta) represents a family of polypeptide growth factors, involved in inflammation and regulation of immune responses. The purpose of this study was to determine whether polymorphisms in the TGF-beta 1 gene may confer susceptibility to adult periodontitis. MATERIAL AND METHODS: We studied 90 patients with adult periodontitis together with 108 unrelated subjects. 3 polymorphisms located in the 5'region at positions -988 (C/A), -800 (G/A) and -509 (C/T) and 2 polymorphisms located at codons 10 (L10P) and 25 (R25P) of exon 1 were investigated by PCR methods. RESULTS: There was no statistically-significant difference in genotype or allele frequency distributions between patients and reference group for the -800G/A, -509C/T, L10P and R25P polymorphisms (p>0.05 in all cases). The -988 A polymorphism was present neither in our patients nor in unrelated subjects. Upon stratification for smoking status no significant differences were found in the TGF-beta 1 genotype or allele frequencies either between adult periodontitis smokers compared to control smokers, or between periodontitis non-smokers and control non-smokers. CONCLUSION: These data indicate that the mentioned polymorphisms of the TGF-beta 1 gene do not influence susceptibility to adult periodontitis. There was no association between any polymorphisms in the TGF-beta 1 gene, severity of periodontitis and the smoking status in our study.     

非综合征型唇腭裂与新疆维吾尔族、汉族 MTHFR 基因多态性的研究

目的：探讨新疆维吾尔族、汉族非综合征型唇腭裂与 MTHFR 基因多态性的关系和民族差异。方法：170例 NSCL／P儿童患者和100例健康儿童对照,SNaPshot 分型方法检测 rs1801131、rs1801133位点多态性,分析基因型、等位基因频率和2个位点联合作用与 NSCL／P 的关系以及民族间差异。结果：rs1801133TT 与 T 等位基因在维、汉两民族间有统计学差异（P ＜0．05）;rs1801133CT 与 CT ＋TT 基因型在总病例组和总对照组间均有统计学差异（P ＜0．05）;rs1801131和 rs1801133的联合分析在维族内、汉族内、两民族间、维汉总人群中病例组和对照组均有统计学差异（P ＜0．05）;rs1801131多态性在维族内、汉族内、两民族间以及维汉总人群中均无统计学差异（P ＞0．05）。结论：rs1801133TT 与 T 等位基因的汉族比维吾尔族更易罹患 NSCL／P;rs1801131AC 和 rs1801133CC 联合作用与 NSCL／P 相关且维吾尔族罹患风险高于汉族;rs1801131多态性与 NSCL／P 不相关并无民族差异;rs1801133CT 与 CT ＋TT 基因型均是避免疾病的保护因素。     

The CD14 -159C-to-T promoter polymorphism in periodontal disease

BACKGROUND: A single-nucleotide promoter polymorphism in the CD14 gene was associated with various inflammatory conditions. The present study sought to determine the frequency of the CD14 -159C-to-T polymorphism among subjects with periodontitis and healthy control individuals. METHODS: A total of 70 patients with periodontal disease and 75 healthy controls were genotyped for the CD14 -159C-to-T polymorphism. Genotyping was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. The allele frequencies and distribution of genotypes within both study groups were compared using Fisher's exact test at a level of significance of 5% (p<0.05). RESULTS: Overall, the frequency for the CD14 -159T allele in patients with periodontitis was 39.3% (55/140) and 48.0% (72/150) for the controls (p=0.135). The CD14 -159C allele was significantly more prevalent (p=0.013) among females with periodontitis (33.3%; 24/72) as compared with healthy control subjects (55.6%; 30/54). In contrast, the distribution of the CD14 -159C-to-T polymorphism showed no significant difference among males with and without periodontitis (p=0.816). CONCLUSION: Herein, the C -159T promoter polymorphism of the CD14 gene was associated in female but not in male patients with periodontal disease.     

Association Between Interleukin‐4 Gene −590 C/T, −33 C/T,and 70‐Base‐Pair Polymorphisms and Periodontitis Susceptibility: A Meta‐Analysis

Background: Several studies have investigated the association between interleukin (IL)‐4 gene ?590 C/T, ?33 C/T, or 70–base pair (70‐bp) polymorphisms and periodontitis susceptibility but with conflicting results. Hence, a meta‐analysis was conducted to explore whether these polymorphisms are associated with periodontitis susceptibility. Methods: A comprehensive literature search was conducted of PubMed, Embase, Scopus, ScienceDirect, and Web of Science up to April 5, 2014. After the eligible studies were identified, data were extracted and quality‐assessed before performing the meta‐analysis. Results: The meta‐analysis included 23 eligible case‐control studies from 11 articles involving 12 studies of the ?590 C/T polymorphism (1,220 cases and 2,039 controls), five of the ?33 C/T polymorphism (715 cases and 967 controls), and four of the 70‐bp polymorphism (426 cases and 506 controls). The meta‐analysis showed that none of these IL‐4 gene polymorphisms were significantly associated with periodontitis susceptibility in all study participants. However, subgroup analysis showed that the IL‐4 ?590 T allele (odds ratio [OR] = 1.2, 95% confidence interval [CI] = 1.02 to 1.42, P = 0.03) and TT genotype (OR = 1.68, 95% CI = 1.05 to 2.67, P = 0.03) were associated with periodontitis in whites. Conclusions: Based on current evidence, the IL‐4 ?33 C/T and 70‐bp polymorphisms were not associated with an increased risk of periodontitis. However, the IL‐4 ?590 T allele and TT genotype were associated with increased risk of periodontitis in whites.     

Relation of vitamin D and BsmI variant with temporomandibular diseases in the Turkish population

Vitamin D (VD) levels and several variants in the vitamin D receptor (VDR) gene are associated with the occurrence of diseases of the bones and cartilage. The aim of this research was to study and compare the association of the BsmI variant in the VDR gene as well as VD levels in disc displacement with reduction (DDR) between patients and healthy controls. This was a case-control study, in which 104 patients of DDR and 102 healthy individuals were studied. The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) was used to diagnose temporomandibular diseases. The VDR BsmI variant was investigated, after extraction of genomic DNA, by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and the VD level in serum was measured. The serum VD level was significantly different between the patient and the control group (mean (SD) 13.20 (11.02) ng/mL versus 18.44 (10.03) ng/mL, respectively) (p=0.008). Serum VD assessment revealed that serious vitamin D deficiency was more prevalent in the patients than the controls (50.96% versus 21.56%) (p=0.00001). Logistic regression analysis revealed that the bb genotype and b allele carriers of VDR BsmI variant were significantly associated with increased risk of DDR (p=0.022 and p=0.01, respectively). VDR BsmI BB genotype was higher in the control group than the patient group (p=0.045). Genotype distributions for BsmI variant in the controls and the patients were confirmed using the Hardy-Weinberg equilibrium equation. The BsmI variant of the VDR gene and VD deficiency play role in DDR aetiopathogenesis in a Turkish population. Vitamin D level and VDR BsmI variation may be effective in a possible genetic-based DC/TMD Axis III to be created in the future.     

5,10‐Methylenetetrahydrofolate reductase single nucleotide polymorphisms and gene–environment interaction analysis in non‐syndromic cleft lip/palate

Non‐syndromic cleft lip/palate (NSCL/P) is a common congenital defect in Mexico. Periconceptional intake of folic acid (FA) may reduce the risk of this malformation. Although the 5,10‐methylenetetrahydrofolate reductase (MTHFR) enzyme participates in folate metabolism, several studies failed to find any association between NSCL/P and the MTHFR C677T and A1298C polymorphisms. However, interactions among NSCL/P, MTHFR gene polymorphisms, and FA intake have not been explored in Mexican populations. This case–control study included 132 patients with NSCL/P and 370 controls from Mexico City. Maternal FA consumption during pregnancy was examined, as were the MTHFR C677T and A1298C polymorphisms and gene–FA interactions. Maternal FA intake during the periconceptional period was lower in cases (1.5%) than in controls (13%), with the risk of delivering a child with NSCL/P lower in mothers who consumed FA (OR = 0.29, 95% CI: 0.19–0.44). In addition, the risk of NSCL/P was lower in children with the TT than the CC genotype of MTHFR C677T (OR = 0.39, 95% CI: 0.23–0.68), after Bonferroni correction and exclusion of stratification. No evidence of gene–FA interaction was found. These results indicate that maternal FA intake and the TT genotype of the MTHFR C677T polymorphism in children independently reduced the risk of NSCL/P in our population.     

维生素D受体和雌激素受体基因多态性与慢性牙周炎的相关性

目的 探讨维生素D受体、雌激素受体基因型与慢性牙周炎的相关性,比较宿主携带的各基因型对慢性牙周炎临床指标的影响.方法 将106例中、重度慢性牙周炎患者(牙周炎组)及80名牙周健康者(对照组)作为研究对象,采用Florida探针检测牙周炎患者的牙周探诊深度、临床附着丧失、龈沟出血指数、松动度等临床指标;抽取所有研究对象的前臂静脉血,饱和NaCl法提取DNA后使用聚合酶链反应(PCR)和酶切相结合的方法检测牙周炎组及对照组维生素D受体基因和雌激素受体基因的多态性,Z检验和方差分析进行数据分析.结果 慢性牙周炎患者携带维生素D受体BB基因型的个体百分比为43.4%,健康对照组为30.0%;慢性牙周炎患者携带雌激素受体XX基因型的个体百分比为39.6%,健康对照组为20.0%,差异有统计学意义(P<0.01).同时携带维生素D受体BB基因型、雌激素受体XX基因型的个体牙周状况较携带其他基因型的个体差.结论 维生素D受体等位基因B、雌激素受体等位基因X是中、重度慢性牙周炎的易感等位基因;这两种等位基因的共同携带对慢性牙周炎的病情进展有一定的促进作用.     

Genetic variations in the human gelatinase A (matrix metalloproteinase-2) promoter are not associated with susceptibility to, and severity of, chronic periodontitis

BACKGROUND: Gelatinase A (matrix metalloproteinase-2 [MMP-2]) has been shown to play an important role in the pathogenesis of several disorders, including periodontal diseases. In this study, we test the hypothesis that variations in this gene influence the development and severity of chronic periodontitis. METHODS: Four promoter polymorphisms (-1575G/A, -1306C/T, -790T/G, and -735C/T) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods in 149 patients with mild to severe chronic periodontitis and 127 age-matched controls in the Czech population. RESULTS: No significant differences in distribution of the -1575G/A, -1306C/T, and -735C/T variants between periodontitis and control groups were detected in our study. However, a trend to decreased frequency of the -790 GG homozygotes was observed in patients with chronic periodontitis compared to healthy controls (P = 0.036, P (corr) >0.05). Haplotype analysis of four single nucleotide polymorphisms (SNP) in the MMP-2 gene showed no significant association of any haplotype with chronic periodontitis. CONCLUSION: Our findings suggest that polymorphisms in the MMP-2 gene promoter do not contribute significantly to the interindividual periodontitis susceptibility and/or severity in European Caucasians, and they are not regulatory variants in this disease.     

白细胞介素8基因-251位点多态性与侵袭性牙周炎的相关性研究

目的研究白细胞介素8（interleukin-8,IL-8）-251位点基因多态性与侵袭性牙周炎易感性的相关性。方法采用病例对照试验设计,从广东汉族人群中选择77例侵袭性牙周炎（aggressive periodontitis,AgP）患者（AgP组）及50例牙周健康者（健康对照组）,采用聚合酶链反应—限制性内切酶片段长度多态性方法对IL-8-251位点基因进行检测,分析组间等位基因和基因型频率的分布差异。结果 IL-8-251A/T位点的基因型和A、T等位基因频率在AgP组和健康对照组的分布差异无统计学意义（P〉0.05）。结论未发现IL-8-251A/T位点基因多态性与中国广东汉族人群侵袭性牙周炎的患病易感性之间存在相关性。     

IL-10-819位点基因多态性与汉族人群重度慢性牙周炎易感性相关性的研究

目的　探讨IL 10启动子区基因多态性与重度慢性牙周炎易感性的关系。方法　收集 14 2名重度慢性牙周炎患者和 81名健康对照者的颊粘膜拭子 ,提取DNA ,采用ASO PCR方法检测IL 10 819位点基因多态性 ,比较重度慢性牙周炎患者和健康对照组中等位基因频率和基因型分布。结果　IL 10 819C/T等位基因频率和基因型分布在患者和对照组之间差异无显著性 (OR =1.377,P =0 .12 2 >0 .0 5 )。结论　IL 10 819位点基因多态性与汉族人群重度慢性牙周炎遗传易感性无相关关系。     

Association of matrix metalloproteinase-9 promoter gene polymorphism with chronic periodontitis

BACKGROUND: Matrix metalloproteinases (MMPs) are related to tissue destruction and remodeling events in periodontal diseases. A single nucleotide polymorphism in the promoter region of human MMP-9 gene is associated with the risk of some inflammatory diseases. Therefore, the aim of this study was to investigate the association between MMP-9 promoter polymorphism and severe generalized chronic periodontitis in a Turkish population. METHODS: Samples of venous blood and DNA were obtained from 70 severe generalized chronic periodontitis patients and 70 healthy subjects. The alleles of the C/T polymorphism at position -1562 in the promoter region of the MMP-9 gene were distinguished by cutting with the SphI restriction enzyme. Genotype and allele frequencies were calculated, and data were analyzed by the chi2 test. RESULTS: There was a significant difference in MMP-9 genotypes between chronic periodontitis patients and healthy controls. The odds ratios for the CT genotype and the combination of CT and TT genotypes were 0.4 (95% confidence interval, 0.17 to 0.93; P=0.02) and 0.37 (95% confidence interval, 016 to 0.85; P=0.01) relative to the subjects with the CC genotype, respectively. CONCLUSION: MMP-9 promoter gene polymorphism seems to be associated with severe generalized chronic periodontitis.     

DHFR基因rs11742688位点单核苷酸多态性与中国东北人群唇腭裂相关性研究

目的：探讨二氢叶酸还原酶（DHFR）基因 rs11742688位点单核苷酸多态性与中国东北部人群的非综合征唇腭裂（NSCL／P）的相关性。方法：采用聚合酶链－限制性片段长度多态性方法检测东北地区220例 NSCL／P 及其父母（其中包括138例完整的核心家系）,180例正常儿童作为对照组,进行 HW 平衡检验,用 SPSS 统计学软件对病例组和对照组进行检验及计算 OR 值和95％可信区间。结果：病例对照研究结果显示,东北地区单纯唇裂和唇腭裂 rs11742688位点的 TT 基因型频率差异无显著性（χ2＝0．439,P ＞0．05）。结论：DHFR rs11742688位点 T 等位基因与东北人群的 NSCL／P 无相关性。     

S100A8基因多态性与侵袭性牙周炎易感性的相关研究

目的　筛选S10 0A8基因上游调控区的单核苷酸多态性位点 ,研究其与侵袭性牙周炎易感性的关系。方法　提取 30例侵袭性牙周炎患者和 2 8名健康对照者的基因组DNA ,行聚合酶链(PCR)反应及PCR产物直接测序。结果　S10 0A8翻译起始位点上游 94bp处存在一个A→G的替换 ,该替换位于顺式作用元件———γ 干扰素反应元件。所有具有等位基因G的个体均为杂合子。两组基因型和等位基因的分布差异均无统计学意义 (2 3 2 %vs 35 7% ,11 7%vs 17 9% ,P >0 0 5 )。结论　初步研究显示 ,S10 0A8基因该位点的多态性与侵袭性牙周炎的易感性无明显相关性 ,但有必要扩大样本进一步研究。     

FcγRⅢB基因、G2m(23)因子与侵袭性牙周炎的研究

目的　探讨中性多形核白细胞 (polymorphonuclearneutrophils ,PMNs)表面FcγRⅢb受体遗传多态性及人类免疫球蛋白G重链遗传标记因子 G2m(2 3)因子与侵袭性牙周炎的关系。方法　侵袭性牙周炎患者 2 1例 ,健康对照 2 6名 ,提取静脉血基因组DNA及血清 ,分别用PCR和免疫斑点的方法测定FcγRⅢb基因型和G2m(2 3)因子。结果　侵袭性牙周炎患者FcγRⅢBNA1 /NA1基因型检出率高于健康对照 (P <0 0 5) ;侵袭性牙周炎患者中FcγRⅢb基因型为NA1 /NA1 ,并且G2m(2 3)阳性的个体比率比健康对照组高 (P <0 0 5) ;G2m(2 3)因子在侵袭性牙周炎患者与健康对照组中的分布差异无显著性。结论　FcγRⅢBNA1 /NA1基因可能是中国人侵袭性牙周炎的易感基因 ;FcγRⅢb基因型为NA1 /NA1 ,G2m(2 3)阳性的中国人可能更容易患侵袭性牙周炎     

The association of interleukin-4 haplotypes with chronic periodontitis in a Czech population

BACKGROUND: Cytokine gene polymorphisms are known to influence the susceptibility and disease course of many chronic disorders. Recently, interleukin (IL)-4 gene polymorphisms were associated with aggressive periodontitis. The aim of this study was to test differences in the distribution of the IL-4 alleles, genotypes, and haplotypes between patients with chronic periodontitis (CP) and healthy controls in a Czech population. METHODS: The association study was conducted using an age- and smoking status-matched case-control design in patients with CP (n = 194) and healthy controls (n = 158) using the polymerase chain reaction-restriction fragment length polymorphism methods for the -590C/T, -33C/T, and intron 3 variable number tandem repeat (VNTR) variants of the IL-4 gene. RESULTS: No significant differences between patients and controls were found in allele and genotype frequencies of all three polymorphisms. Nevertheless, complex analysis revealed significant differences in haplotype frequencies between the groups (P = 0.005). The haplotype T(-590)/T(-33)/allele 2 VNTR (70 base pairs)(2) of the IL-4 gene was significantly more frequent in patients with CP than in controls (17.0% versus 11.0%; odds ratio = 1.85; 95% confidence interval: 1.19 to 2.87). CONCLUSION: The three polymorphisms in the IL-4 gene act in a cooperative fashion and suggest that the high-production IL-4 haplotype was associated with an increased risk for CP in the Czech population.     

Analysis of the MMP-9 (C-1562 T) and TIMP-2 (G-418C) gene promoter polymorphisms in patients with chronic periodontitis

BACKGROUND: Matrix metalloproteinases (MMP)-9 is an important member of the matrix metalloproteinase family. A functional polymorphism has been described in the promoter region of the human MMP-9 gene. A C-to-T base exchange at -1562 creates two different alleles, and the C/T and T/T genotypes promote high activity of the MMP-9 gene promoter, increasing the risk for inflammatory diseases. The metalloproteinase-2 tissue inhibitor (TIMP-2) regulates the activity of MMPs in the extracellular matrix, and a polymorphism at the -418 position of the TIMP-2 gene promoter has been found in a Sp-1 binding site. In this study we have investigated the association between the above-mentioned polymorphisms and chronic periodontitis severity. METHODS: Genomic DNA from oral mucosa of 100 subjects was amplified by polymerase chain reaction and analysed by restriction endonuclease digestion. The significance of the differences in observed frequencies of polymorphisms in moderate and severe disease and healthy groups was assessed by chi(2) test (p<0.05). RESULTS: No association was observed between the polymorphism in the promoter region of MMP-9 (p=0.6693) and chronic periodontitis. The analysis of TIMP-2 showed that the G/G genotype was found at a frequency of 99%. CONCLUSION: The results show that the polymorphism in the promoter region of MMP-9 gene is not associated with chronic periodontitis. The high frequency of GG genotype in the TIMP-2 gene promoter in the population studied did not allow any conclusion regarding its effect on chronic periodontitis.