RESUMEN
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.
Asunto(s)
Metaloproteinasa 1 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Trastornos de la Articulación Temporomandibular/enzimología , Trastornos de la Articulación Temporomandibular/genética , Adulto , Alelos , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Desequilibrio de Ligamiento , Modelos Logísticos , Imagen por Resonancia Magnética , Masculino , Cóndilo Mandibular/diagnóstico por imagen , Cóndilo Mandibular/patología , Persona de Mediana Edad , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas/genética , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Polymorphisms, such as a guanine inserted at position -1607 in the promoter region of human matrix metalloprotenase 1 (MMP-1) or a C-1562T substitution in the MMP-9 gene, have been shown to increase the transcriptional activity of these MMPs. The objective of this study was to investigate the possible relationship between these polymorphisms and early implant failure. MATERIALS AND METHODS: Genomic DNA from oral mucosa was amplified by polymerase chain reactions (PCRs) and analyzed by restriction endonucleases. The significance of the differences in observed frequencies of polymorphisms was assessed by the chi-square and Fisher exact tests. RESULTS: The test group comprised patients with early failure of osseointegrated oral implants. In the MMP-1 gene, 2G allele was observed in 25% of the control group and in 50% of the test group (P = .013). The genotype 1G/1G was found in 61.5% of the control group, while all patients in the test group had the genotype 1G/2G (P < .001). No differences were seen in the allele and genotype frequencies in the MMP-9 gene among the groups (P = .15 and P = .13, respectively). DISCUSSION AND CONCLUSION: These results suggest that polymorphism in the promoter region of the MMP-1 gene may be associated with early implant failure, while polymorphism in the promoter region of the MMP-9 gene may not have a relationship with implant loss.
Asunto(s)
Implantes Dentales , Fracaso de la Restauración Dental , Metaloproteinasa 1 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Oseointegración/genética , Adolescente , Adulto , Anciano , Alelos , Distribución de Chi-Cuadrado , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mucosa Bucal/citología , Polimorfismo de Longitud del Fragmento de Restricción , Regiones Promotoras GenéticasRESUMEN
OBJECTIVE: The aim of the present study was to investigate the relationship between specific polymorphisms of the interleukin-1 gene cluster and the early failure of osseointegrated implants. MATERIAL AND METHODS: The subject population was composed by a test group comprising 28 non-smoking patients (mean age 52.7) that had suffered one or more early implant failures and by a control group consisting of 34 individuals (mean age 43.3) with one or more healthy implants. Genomic DNA from buccal mucosa was amplified by the polymerase chain reaction (PCR), followed by restriction fragment length polymorphism (RFLP) and submitted to polyacrylamide gel electrophoresis to distinguish the alleles of the interleukin-1A (-889), interleukin-1B (+3953), interleukin-1B (-511) and interleukin-RN (intron 2) gene polymorphisms. Differences in the allele and genotype frequencies between control and test groups were assessed by chi(2) test or by Monte Carlo simulations (P<0.05). Haplotype frequencies, linkage disequilibrium and Hardy-Weinberg equilibrium were also estimated. RESULTS: No statistically significant differences were found in the genotype distribution or allelic frequencies of the polymorphisms. No differences were observed between control and test groups when different interleukin-1 gene cluster haplotypes were compared. Nevertheless, the interleukin-1A (-889) and interleukin-1B (+3953) polymorphic sites were in strong linkage disequilibrium (P=0.00014 for control group and P=0.0238 for the test group). CONCLUSION: This study suggests that polymorphisms in the interleukin-1 gene cluster are not associated with early implant failure in a non-smoking Brazilian population.