Association of matrix metalloproteinase-1-1607 1G/2G single nucleotide polymorphism genotypes with periodontitis in Iraqi population / Associação entre genótipos de polimorfismo de nucleotídeo único de metaloproteinase-1-1607 1G/2G da matriz e periodontite em população iraquiana

Objective and background: Periodontitis is an inflammatory disease which is characterized by a progressive loss in the matrix of soft and hard tissue of periodontium particularly the collagen fibers which are cleaved by matrix Metalloproteinase (MMP). Indeed, increased activity of MMP mediates progression of periodontal diseases but population-based genetic variations could determine the susceptibility to the disease. The aim was to investigate association between MMP-1-1607 polymorphism with periodontitis among Iraqi individuals. Subjects and methods: The design of this study was a case-control for Iraqi individuals who were divided into two groups; periodontitis group (cases) and those with healthy periodontium (Control). For each subject, clinical periodontal parameters and demographic characteristics were recorded and venous blood was withdrawn for genetic analysis of MMP-1 by using PCR technique and DNA sequencing. Results: Analysis of MMP-1-1607 genotypes, by Hardy-Weinberg equilibrium, showed significant differences in the total sample. The most predominant MMP-1-1607 genotype among Controls was 1G/2G which was significantly different from periodontitis cohorts. Overall, 13 SNP were detected in periodontitis group versus 17 SNP in Control group. In addition, the periodontitis group showed a significant negative association between the probing pocket depth and MMP-1-1607. Conclusion: Results suggested that polymorphisms in MMP-1-1607 1G/2G may play a protective role and decreasing the susceptibility to periodontitis. (AU)

Introdução e objetivo: A periodontite é uma doença inflamatória caracterizada pela perda progressiva da matriz dos tecidos moles e duros do periodonto, particularmente as fibras de colágeno clivadas pelas metaloproteinases da matriz (MMPs). De fato, o aumento da atividade de MMPs medeia a progressão das doenças periodontais, mas as variações genéticas baseadas na população podem determinar a suscetibilidade à doença. O objetivo foi investigar a associação entre o polimorfismo MMP-1-1607 e periodontite em indivíduos iraquianos. População e método: O desenho deste estudo foi um caso-controle com indivíduos iraquianos, os quais foram divididos em dois grupos: grupo periodontite (casos) e indivíduos com periodonto saudável (controle). Para cada sujeito, os parâmetros clínicos periodontais e as características demográficas foram registrados, e o sangue venoso foi coletado para análise genética de MMP-1 por meio da técnica de PCR e sequenciamento de DNA. Resultados: A análise dos genótipos MMP-1-1607, pelo equilíbrio de Hardy-Weinberg, mostrou diferenças significativas na amostra total. O genótipo MMP-1-1607 mais predominante entre os controles foi 1G/2G, o qual foi significativamente diferente das coortes de periodontite. No geral, 13 SNP foram detectados no grupo periodontite versus 17 SNP no grupo controle. Além disso, o grupo periodontite mostrou uma associação negativa significativa entre a profundidade da bolsa de sondagem e MMP-1-1607. Conclusão: Os resultados sugerem que polimorfismos em MMP-1-1607 1G/2G podem desempenhar um papel protetor e diminuir a suscetibilidade à periodontite. (AU)

Prevalence of impacted mandibular third molars and its association with distal caries in mandibular second molars using cone beam computed tomography / Prevalencia de terceros molares mandibulares impactados y su asociación con caries distales en segundos molares mandibulares mediante tomografía computarizada de haz cónico

This study evaluated the prevalence and eruption's pattern of impacted mandibular third molars (IMTM) and the influence of their eruption status on the distal caries of mandibular second molars (MSM) using cone-beam computed tomography (CBCT). Material and methods: CBCT images taken for different purposes in private dental practices were analyzed retrospectively. Radiographic assessment included: prevalence of IMTM, degree of angulation, level of impaction and type of IMTM. Furthermore, the distance between the cement-enamel junctions (CEJ) of second and third molars and the occurrence of caries lesion on the distal surface of MSM was also evaluated. Data were analyzed by chi square test and logistic regression was used to find the association between distal caries of MSM and eruption status of IMTM. Results: Three hundred and eight CBCTs were screened, the prevalence of IMTM was 36.88% and their angulation degree were mostly less than 90º (mesioangular). Amongst those with impaction, 58 subjects (43%) had distal caries on MSM, 29.6% in females and 30.4% in the age group 19-27 years. Caries on the distal side of MSM were significantly associated with age, level and type of impaction, angulation degree and CEJ distances (p<0.05). Conclusions: The prevalence of IMTM is high (36.88%) and there are significant relationships between angulation degree, level and type of impaction, and CEJ distances with caries on the distal side of MSM.

Introducción: Este estudio evaluó la prevalencia y el patrón de erupción de terceros molares mandibulares impactados (TMMI), y la influencia de su estado de erupción en la caries distal de los segundos molares mandibulares (SMM) mediante tomografía computarizada de haz cónico (TCHC). Material y métodos: se analizaron retrospectivamente las imágenes de TCHC tomadas para diferentes fines en prácticas dentales privadas. La evaluación radiográfica incluyó: prevalencia de TMMI, grado de angulación, nivel de impacto y tipo de TMMI. Además, también se evaluó la distancia entre la unión amelocementaria (UAC) de los segundos y terceros molares y la aparición de lesión de caries en la superficie distal de SMM. Los datos se analizaron mediante la prueba de chi cuadrado y se usó la regresión logística para evaluar asociaciones entre la caries distal de SMM y el estado de erupción de TMMI. Resultados: Se examinaron 308 TCHC, la prevalencia de TMMI fue de 36.88% y su grado de angulación fue mayoritariamente menor a 90º (mesioangular). Entre aquellos con impacto, 58 sujetos (43%) tenían caries distales en los SMM, 29.6% eran mujeres y 30.4% pertenecieron al grupo de edad de 19-27 años. Las caries en el lado distal de MSM se asociaron significativamente con la edad, el nivel y el tipo de impactación, el grado de angulación y las distancias UAC (p<0.05). Conclusiones: la prevalencia de TMMI es alta (36.88%) y existen relaciones significativas entre el grado de angulación, el nivel y el tipo de impacto, y las distancias UAC con presencia de caries en el lado distal de los SMM.