Genetic Polymorphism in MMP9 May Be Associated With Anterior Open Bite in Children

Abstract Anterior open bite (AOB) has a multifactorial etiology caused by the interaction of sucking habits and genetic factors. The aim of this study was to evaluate the association between AOB and polymorphisms in genes that encode Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). Four hundred and seventy-two children that presented at least one sucking habit were evaluated. Children were examined clinically for the presence of AOB. Genomic DNA was extracted from saliva. Genotyping of the selected polymorphisms in MMP2, MMP3, MMP9, TIMP1 and TIMP2 was carried out by real-time PCR using the TaqMan method. Allele and genotype frequencies were compared between the groups with and without AOB using the PLINK® software in a free and in a recessive model using a chi-square test. Logistic regression analysis was implemented (p≤0.05). Two hundred nineteen children had AOB while 253 did not. The polymorphism rs17576 in MMP9 was significantly associated with AOB (p=0.009). In a recessive model GG genotype was a protective factor for AOB (p=0.014; OR 4.6, 95%CI 1.3-16.2). In the logistic regression analysis, none of the genes was associated with AOB. In conclusion, the polymorphism rs17576 (glutamine for arginine substitution) in MMP9 was a protective factor for AOB.

Resumo A mordida aberta anterior apresenta uma etiologia multifatorial causada pela interação entre hábitos de sucção e fatores genéticos. O objetivo deste estudo foi avaliar a associação entre mordida aberta anterior e polimorfismo nos genes que codificam as metaloproteinases da matriz (MMPs) e seus inibidores teciduais (TIMPs). Foram avaliadas 472 crianças que apresentvam pelo menos um hábito de sucção. As crianças foram clinicamente examinadas para avaliar a presença de mordida aberta anterior. DNA genômico foi extraído da saliva. A genotipagem dos polimorfismos selecionados em MMP2, MMP3, MMP9, TIMP1 e TIMP2 foi realizada por PCR em tempo real, usando o método de TaqMan. As frequências alélicas e genotípicas foram comparadas entre os grupos com e sem mordida aberta anterior usando o software PLINK®. Duzentas e dezenove crianças apresentavam mordida aberta anterior enquanto 253 não a apresentavam. O polimorfismo rs17576 em MMP9 estava significativamente associado com mordida aberta anterior (p=0,009). No modelo recessivo (GG versus AG+AA) o genótipo GG foi um fator protetor para mordida aberta anterior (p=0,014; OR 4,6; 95%CI 1,3- 16,2). Concluindo, o polimorfismo rs17576 (substituição de glutamina por arginina) em MMP9 está associado com mordida aberta anterior. Os resultados obtidos suportam a hipótese de que fatores genéticos estão envolvidos com a etiologia da mordida aberta anterior.

Dientes supernumerarios: Reporte de un caso clínico / Supernumerary teeth: Clinical case report

Los dientes supernumerarios son anomalías en el desarrollo dental que pueden estar o no asociadas a algún síndrome; su prevalencia oscila entre 0.3 y 3.8% y su incidencia entre 0.1 y 3.8% de acuerdo a la población de estudio. Estos dientes pueden presentarse en la línea media (mesiodens) en un 48.6%, siendo el más común de los dientes; le siguen los premolares con un 26.4%, los laterales con 11.1% y los molares en un 9.7%. Su diagnóstico se realiza mediante un estudio radiológico (radiografía panorámica). Los dientes supernumerarios tienen una morfología variada, pueden ser dismórficos o cónicos, eumórficos o suplementarios; son una duplicación de los dientes de la serie normal y molariforme que suelen presentar una forma molar irregular. Los dientes supernumerarios suplementarios se encuentran en la dentición caduca, no poseen ninguna variedad anatómica; los dientes supernumerarios rudimentarios se presentan en la dentición permanente y tienen variedad anatómica. Después del diagnóstico radiológico de los dientes supernumerarios se procede a realizar el tratamiento quirúrgico. El objetivo de este artículo es reportar un caso clínico de dos dientes supernumerarios, en una paciente de 9 años de edad que no presenta ningún síndrome, en este artículo se discute su relevancia e implicaciones en la práctica clínica.

Supernumerary teeth are anomalies of dental development. They may or may not be associated to different syndromes. Prevalence of this condition varies from 0.3% to 3.8% and incidence can be placed from 0.1% to 3.8 %, according to the studied population group. In 48.6% of all cases, supernumerary teeth can be present at the midline (mesiodens), which is the most common occurrence, followed by premolars, in 26.4% of all cases, laterals in 11.1% and molars in 9.7%. Diagnosis is emitted after x-ray studies (panoramic x-ray). Supernumerary teeth present different morphologies, they can be dysmorphic or conical, eumorphic or supplementary. They are a duplication of normal and molar shaped series of teeth which present irregular molar shape. Supplementary SN teeth are found in primary dentition and do not possess any anatomical variety. Rudimentary SN teeth are found in permanent dentition and possess anatomical variety. After supernumerary teeth x-ray diagnosis, surgical treatment is undertaken. The aim of the present article is to report the clinical case of two supernumerary teeth present in a non-syndromic 9 year old patient. Relevance and implications in clinical practice are discussed in the present article.

Prevalencia de maloclusiones en un grupo de estudiantes universitarios mexicanos y su posible asociación con la edad, el sexo y el nivel socioeconómico, 2009 / Prevalence of malocclusions in a group of Mexican university students and its possible association with age, sex, and socioeconomic status, 2009

Introducción: la oclusión dental hace referencia a la relación que guardan los dientes entre sí en estado de reposo, la cual puede verse alterada por múltiples factores. El estudio tuvo como propósito evaluar la prevalencia de maloclusiones dentales y su posible relación con la edad, el sexo y el nivel socioeconómico, en un grupo de estudiantes universitarios. Métodos:la encuesta epidemiológica sedesarrolló en dos momentos: la aplicación de un cuestionario y el examen bucal, para tal fin dos examinadoras fueron estandarizadas (Cr= 0,03, Ca = 0,89, k = 0,902).Resultados: el 47,7% de los estudiantes correspondió a la clase media. El 13,2% presentó normoclusión y 86.8% maloclusión dental. Su distribución por edad, sexo y nivel socioeconómico no mostró diferencias estadísticamente significativas. En relación con los tipos de maloclusión la más frecuente fue la clase I (37,3%), frecuencia que resultó ser menor a lo esperado, con base en el comportamiento de este mismo evento en poblaciones similares. Conclusiones:lo único que mostró el comportamiento observado, es que el nivel socioeconómico no es un factor que se encuentre asociado a la frecuencia del tipo de oclusión dental en esta población, por lo que abre las expectativas para que se explore en función de otros, tales como los de tipo cultural y educativo.

Introduction: dental occlusion refers to the relationships of teeth at rest; it may be altered by a variety of factors. The purpose of this study was to evaluate the prevalence of dental malocclusions and their possible relations to age, sex, and socioeconomic status in a group of university students. Methods: the epidemiological survey was conducted in two moments: application of a questionnaire, and an oral examination. Two examiners were standardized for this purpose (Cr = 0.03, Ca = 0.89, k = 0.902). Results: 47.7% of the students come from the middle class. 13.2% presented normal occlusion, and 86.8% had dental malocclusion. Their distribution per age, sex, and socioeconomic status did not show statistically significant differences. Concerning malocclusion classification, the most common one was Class I (37.3%), a figure which happened to be lower than expected, in comparison to the same condition in similar populations. Conclusions: the only conclusion drawn from this study is that socioeconomic status is not a factor associated to the frequency of dentalocclusion classification in this population, so there might be other factors to be evaluated, such as cultural and educational factors.

Traumas dentoalveolares relacionados con maloclusiones en menores de 15 años / Dentoalveolar traumata related to malocclusions in children aged under 15

Se realizó un estudio descriptivo de corte transversal, sobre los traumatismos dentoalveolares en un grupo de pacientes de edades comprendidas entre 0 a 15 años de edad, en el periodo de los meses de enero a diciembre del año 2009, en el Policlínico Universitario Antonio Pulido Humarán, del municipio La Lisa, de La Habana, Cuba. El estudio fue realizado con el propósito de caracterizar los traumatismos dentoalveolares relacionados con maloclusión dentaria. La información se obtuvo por el método de observación mediante el examen clínico, a través del interrogatorio y examen radiográfico, durante un año. La muestra estuvo constituida por 125 pacientes a los que se les diagnosticó al menos, uno de los tipos de traumatismos dentoalveolares. Se seleccionó un individuo control que no tuviera fractura por cada caso del estudio, para determinar la relación del traumatismo con la maloclusión. Se observó que la mayor presencia de traumatismos dentales estuvo en los pacientes afectados por maloclusión, para un 76,8 por ciento. La estimación del riesgo para los traumas con maloclusión fue de 6,78 veces mayor, con resultado muy significativo del X², hubo diferencias significativas entre los grupos de edades, pero no en el sexo(AU)

A cross-sectional and descriptive study was conducted on dentoalveolar traumata in a group of patients aged from 0 to 15 during January to December, 2009 in the Antonio Pulido Humarán University polyclinic to characterize the dentoalveolar traumata due to dental malocclusion. Information was obtained by observation method, by clinical examination through a questioning and radiographic examination over a year. Sample included 125 patients diagnosed at least with one of the dentoalveolar traumata, selecting a control group with presence of fracture and the same age that the case. The greatest presence of dental traumata was those affected by malocclusion for 76,67 percent and the more frequent trauma was the coronary fracture for 49,97 percent specially that no complicated of the crown for a 33,3 percent. We conclude that in occurrence of dentoalveolar traumata the presence of dental malocclusion was marked(AU)

Morfologia dentofacial e características oclusais dos índios Arara: revisitando o papel da hereditariedade e da dieta na etiologia da má oclusão / Dentofacial morphology and occlusal characteristics of Arara indigenous: revisiting the role of heredity and diet in the etiology of malocclusion

A influência da dieta e da hereditariedade nas características dentofaciais foi avaliada através do exame de duas populações indígenas amazônicas divididas por um processo de fissão linear. Os indígenas que constituem a aldeia Arara-Iriri são descendentes de um único casal expulso da aldeia Arara-Laranjal. O crescimento da aldeia Iriri ocorreu pelo acasalamento de parentes próximos, ratificado por um alto coeficiente de consanguinidade (F=0,25, p<0,001). A epidemiologia da má oclusão e das características da face foi analisada nos indivíduos entre dois e 22 anos, das aldeias Iriri (n=46) e Laranjal (n=130). A biometria da dentição e da face foi obtida em 55 indígenas em dentição permanente sem perdas dentárias, através da fotogrametria facial e dos modelos de gesso. O desgaste dentário foi examinado em 126 indivíduos através da análise de regressão múltipla. Os resultados revelaram uma determinação significativa da idade no desgaste dos dentes (R2=87,6, p<0,0001), que se mostrou semelhante entre as aldeias (R2=0,027, p=0,0935). Por outro lado, diferenças marcantes foram observadas nas características dentofaciais. Revelou-se uma face mais vertical (dolicofacial) entre os índios Iriri e o predomínio do tipo braquifacial nos indígenas da aldeia original, corroborado pela fotogrametria. Uma face sagitalmente normal foi observada em 97,7% da aldeia Laranjal, enquanto faces convexas (26,1%, RR-16,96) e côncavas (15,2%, RR=19,78) eram mais prevalentes na aldeia Iriri (p<0,001). A biprotrusão, com consequente redução do ângulo nasolabial, era uma característica comum entre os Arara, porém com maior prevalência no grupo Iriri (RP=1,52, p=0,0002). A prevalência da má oclusão foi significativamente mais alta na aldeia Iriri (RP= 1,75, p=0,0007). A maioria da população da aldeia original (83,8%) apresentou uma relação normal entre os arcos dentários, contudo, na aldeia resultante (Iriri), 34,6% dos indivíduos era Classe III (RP=6,01, p<0,001) e 21,7% era Classe...

The influence of diet and genetics on dentofacial features was examined through the analysis of two split indigenous Amazon populations originated by a process of a linear fission. The Arara-Iriri indigenous are descendants of a single couple who were expelled from a larger village (Arara-Laranjal). In the resultant new village, the initial expansion occurred through the mating of closely related people, causing a high coefficient of inbreeding (F=0.25, p<0.001). The epidemiology of malocclusion and facial characteristics were analyzed in individuals aged from 2 to 22 years, from the Arara-Iriri (n=46) and Arara-Laranjal (n=130) villages. The biometric study of the dentition and face was performed in the permanent dentition of the indigenous without tooth loss (n=55) by facial photogrammetry and dental casts analysis. Tooth wear was examined in 126 individuals in the permanent dentition through multiple regression analysis. Findings pointed out a significant determination of age on tooth wear (R2=87.6, p<0.0001), which was similar between the villages (R2=0.027, p=0.0935). However, we found marked differences in the dentofacial morphology. The indigenous of the Iriri village presented a more vertical face (dolichofacial) compared to the people of the original village, predominantly braquifacial. This clinical data was corroborated by facial photogrammetry. A sagitally normal face was observed in 97.7% of the Laranjal village, while convex (26.1%, RR=16.96) and concave faces (15.2%, RR=19.78) were significantly more prevalent in the Iriri village (p<0.001). Biprotrusion, with consequent reduction of nasolabial angle, was a common feature among the Arara indigenous, but its occurrence in the Iriri village was higher (RP=1.52, p=0.0002). The prevalence of malocclusion was significantly higher in the Iriri population (RP=1.75, p=0.0007). While the majority of the population (83.8%) in the Laranjal village presented a normal ...(AU)

Anomalías dentomaxilofaciales en dientes permanentes y su relación con traumas en la primera infancia / Dental-maxillary-facial anomalies in permanent teeth and their relation to traumas in early childhood

Se realizó un estudio descriptivo, longitudinal y retrospectivo que incluyó niños de 7 a 14 años de edad, pertenecientes al área de salud de la "Clínica Estomatológica Docente Guama" del municipio Pinar del Río, en el período comprendido entre febrero del 2003 a marzo de 2005, con el objetivo de determinar la presencia de anomalías dentomaxilofaciales en dentición permanente y su relación con traumas en la primera infancia. El universo de estudio estuvo constituido por 250 niños, y de ellos, se seleccionó una muestra de 60 niños y se les confeccionó una planilla recolectora de datos para la investigación. Los resultados obtenidos fueron procesados estadísticamente mediante el sistema automatizado STATISTIC y la prueba de CHI CUADRADO, en su aplicación de bondad de ajuste, y el paquete SPSS, para la prueba de comparación de proporciones. En todos los casos se prefija un nivel de significación de 0,05. Entre los resultados globales más significativos encontramos que fueron los traumas ocurridos en las edades de 5-6 años los que más anomalías dentomaxilofaciales causaron en la dentición permanente. Resultó el sexo masculino el más afectado por estas alteraciones, fueron los traumas recibidos directamente sobre los dientes, los mayores causantes de anomalías en la dentición permanente. Resultaron las hipoplasias del esmalte, como otras anomalías no ortodóncicas las más frecuentes; se comprobó que el sexo femenino tuvo mayor implicación psicosocial por estas alteraciones y se divulgaron a estomatólogos, padres y maestros orientaciones sobre la relación entre los traumas en la primera infancia y las anomalías dentomaxilofaciales en la dentición permanente.

A descriptive, longitudinal and retrospective research was carried out including children from 7 to 14 years old belonging to the health area of "Guama" Dental University Clinic in Pinar del Rio Municipality, from February 2003 to March 2005 aimed at determining the presence of dental-maxillary-facial anomalies in permanent teeth and the relation to traumas in early childhood. The universe of the research was comprised of 250 children and of them a sample of 60 children was chosen, giving them a form to collect data for the research. Results obtained were statistically processed through the STATISTIC automatic system and the chi-squared test in its application of kindness-adjustment and SPSS package for the proportion and comparison tests. In all cases 0, 05 was the level of significance pre-fixed. Among the most significant global results obtained, those traumas occurring between 5-6 years of age caused the greater number of dental-maxillary-facial anomalies in permanent teeth. Male sex presented the traumas that most affected permanent teeth directly. The most frequent were the hypoplasia of the enamel and other non-orthodontic entities; female sex had a greater psychosocial implication due to these anomalies. Orientations to dentists, parents and teachers were given about the relation among traumas and dental-maxillary-facial anomalies in permanent teeth.