Relationship between cervical vertebral maturation and dental development in a sample of yemeni children and adolescents / Relación entre la maduración vertebral cervical y el desarrollo dental en una muestra de niños y adolescentes yemeníes

Objective: This study was conducted to investigate the relationship between dental development and cervical vertebral maturation stages in a group of Yemeni children and adolescents. Materials an Methods: The study included digital panoramic radiographs and lateral skull cephalograms obtained from 207 Yemeni subjects­122 females and 85 males aged between 8 to 18 years. Dental maturity was evaluated according to the method of Demirijian et al., calcification stages of the left mandibular canines, first and second premolars and second molars were assessed. Skeletal maturity was assessed by the cervical vertebral maturation (CVM) stages according to the method of Baccetti et al. Correlation between CVM and dental maturation was evaluated by Spearman rank-order correlation coefficient (SROCC). Results: CVM and dental calcification stages were highly correlated (p<0.001) in both genders, ranging from 0.686 to 0.873 for females and 0.787 to 0.871 for males. Calcification stages of the second molars showed the strongest correlation with CVM. Conclusion: Calcification stages of the second molar may be used as a reliable maturation indicator. Dental maturation may be applied to determine the skeletal maturity status of Yemeni children and adolescents.

Objetivo: Este estudio se realizó para investigar la relación entre el desarrollo dental y las etapas de maduración vertebral cervical en un grupo de niños y adolescentes yemeníes. Material y Métodos: El estudio incluyó radiografías panorámicas digitales y cefalogramas laterales del cráneo obtenidos de 207 sujetos yemeníes: 122 mujeres y 85 hombres de entre 8 y 18 años. La madurez dental se evaluó de acuerdo con el método de Demirijian et al. Se evaluaron las etapas de calcificación de los caninos mandibulares izquierdos, primer y segundo premolares y segundos molares. La madurez esquelética se evaluó mediante las etapas de maduración vertebral cervical (CVM) de acuerdo con el método de Baccetti et al. La correlación entre la CVM y la maduración dental se evaluó mediante el coeficiente de correlación de orden de rango de Spearman (SROCC). Resultado: Las etapas de CVM y calcificación dental estuvieron altamente correlacionadas (p<0.001) en ambos sexos, con un rango de 0.686 a 0.873 para las mujeres y 0.787 a 0.871 para los hombres. Las etapas de calcificación de los segundos molares mostraron la correlación más fuerte con CVM. Conclusión: las etapas de calcificación del segundo molar pueden usarse como un indicador de maduración confiable. La maduración dental puede aplicarse para determinar el estado de madurez esquelética de los niños y adolescentes yemeníes.

Resolución de clase II mordida profunda con distalamiento molar mini-iimplantoasistida: reporte de caso clínico / Resolution of a class II deep bite with mini-implant-assisted molar distal movement; report of a clinical case

En todos los tratamientos ortodónticos, el primer objetivo a cumplir es alinear y nivelar las piezas dentales. Para tal fin, deberíamos generar espacio dentro del arco dentario. Existen tres procedimientos diferentes para lograr este objetivo, según el grado de apiñamiento dental o Índice de nance, que son los siguientes: a) stripping o desgaste interproximal, b) exodoncia de piezas dentales y c) distalamiento. La distalización de los molares es una de las técnicas más antiguas de la terapéutica ortodóntica y se han empleado distintos recursos terapéuticos para tal fin, como pendulum, jig de jans, first class, entre otros; cada uno con sus ventajas y desventajas. La introducción de los mini-implantes dentro de nuestra especialidad ha revolucionado en forma drástica los conceptos de anclaje, brindándonos movimientos dentarios sin generar efectos colaterales indeseables. El objetivo de este caso clínico, es mostrar la utilización de un Orthorama modificado y mini-implantes como distaladores de los molares superiores (AU)

Extruded upper first molar intrusion: Comparison between unilateral and bilateral miniscrew anchorage

ABSTRACT Objective: The aim of his study was to evaluate the stress on tooth and alveolar bone caused by orthodontic intrusion forces in a supraerupted upper molar, by using a three-dimensional Finite Element Method (FEM). Methods: A superior maxillary segment was modeled in the software SolidWorks 2010 (SolidWorks Corporation, Waltham, MA, USA) containing: cortical and cancellous bone, supraerupted first molar, periodontal tissue and orthodontic components. A finite element model has simulated intrusion forces of 4N onto a tooth, directed to different mini-screw locations. Three different intrusion mechanics vectors were simulated: anchoring on a buccal mini-implant; anchoring on a palatal mini-implant and the association of both anchorage systems. All analyses were performed considering the minimum principal stress and total deformation. Qualitative analyses exhibited stress distribution by color maps. Quantitative analysis was performed with a specific software for reading and solving numerical equations (ANSYS Workbench 14, Ansys, Canonsburg, Pennsylvania, USA). Results: Intrusion forces applied from both sides (buccal and palatal) resulted in a more homogeneous stress distribution; no high peak of stress was detected and it has allowed a vertical resultant movement. Buccal or palatal single-sided forces resulted in concentrated stress zones with higher values and tooth tipping to respective force side. Conclusion: Unilateral forces promoted higher stress in root apex and higher dental tipping. The bilateral forces promoted better distribution without evidence of dental tipping. Bilateral intrusion technique suggested lower probability of root apex resorption.

RESUMO Objetivos: o presente estudo teve como objetivo avaliar, por meio da Análise de Elementos Finitos, as tensões geradas por forças ortodônticas intrusivas em um molar superior e no osso alveolar circundante. Métodos: um segmento maxilar foi modelado no software SolidWorks 2010 (SolidWorks Corporation, Waltham, MA, EUA), contendo: osso cortical e medular, primeiro molar extruído, tecido periodontal e acessórios ortodônticos. Um modelo de elementos finitos simulou forças intrusivas de 4 N no elemento dentário, aplicadas a partir de mini-implantes em localizações distintas. Três diferentes vetores para mecânica de intrusão foram simulados: ancoragem em mini-implante vestibular, ancoragem em mini-implante palatino ou a associação de ambas. Todas as análises foram realizadas em termos de tensão mínima principal e deformação total. A análise qualitativa foi feita por meio do mapeamento da distribuição das tensões em gradiente de cores. A análise quantitativa foi feita em software específico para leitura e resolução de equações numéricas (ANSYS Workbench 14, Ansys, Canonsburg, Pennsylvania, EUA). Resultados: as forças intrusivas aplicadas simultaneamente nos dois lados (vestibular e palatino) resultaram em uma distribuição mais homogênea das tensões geradas, sem zonas de acúmulo de tensão e com uma resultante vertical para a movimentação intrusiva. As forças aplicadas somente em um lado, vestibular ou palatino, resultaram em zonas de concentração de tensão, com maiores valores, e na inclinação do elemento dentário para o lado em que a força foi aplicada. Conclusão: as forças unilaterais promoveram maior tensão no ápice radicular e maiores inclinações do elemento dentário. Já as forças bilaterais promoveram melhor distribuição das tensões e não resultaram em inclinação do elemento dentário. Assim, as forças intrusivas ancoradas bilateralmente apresentam menor probabilidade de reabsorção do ápice radicular.

Entendendo a anatomia do primeiro molar inferior / Understanding first lower molar anatomy

Para entender a anatomia de cada dente precisamos estudar a sua forma e função, pois cada estrutura está diretamente ligada ao movimento da mandíbula, como altura, inclinação das cúspides e profundidade de fossa. A anatomia deve estar interligada com as condições do antagonista, estando em perfeita harmonia. Este artigo tem a função de detalhar a anatomia do primeiro molar inferior, através de fotos de dentes naturais.

To understand each tooth anatomy, we need to study its shape and function, as each structure is directly linked to the mandible movement, such as height, cusp slope and pit depth. Anatomy must be interconnected with the antagonist conditions, being in perfect harmony. This article has the objective to detail the lower first molar anatomy through photos of natural teeth.

Influencia del tutor en la educación en el trabajo / Tutor's influence in education at work

El método de tutoría actúa de forma flexible y se acomoda a cada uno de los estudiantes, de acuerdo con su personalidad, intereses, conocimientos, capacidades, nivel de dificultades y avances. Actúa dentro de un sistema de enseñanza aprendizaje colectivo. En este proceso juegan un papel importante los factores que influyen en la formación de la personalidad, y dentro de ellos la escuela; que como institución está llamada a cumplir el rol de mayor responsabilidad en la formación de las nuevas generaciones, pero para cumplir con este papel, requiere de un trabajo conjunto con el tutor del área práctica, ya que este resulta un eje fundamental para el desempeño del futuro profesional. En Cuba, en las condiciones de la formación profesionallos tutoresson docentes en ejercicio. Dada la importancia que tiene el tutor y el papel que debe jugar en la práctica profesional, para una correcta contribución a la preparación y formación de los futuros tecnólogos, este artículo se propuso fundamentar el valor que tiene este durante la educación en el trabajo. Se abordan aspectos de gran interés para su desempeño, relacionados con su labor desde el área práctica, incluyendo la formación en valores (AU).

The tutoring method works in a flexible way and is able to accommodate to every of the students according to their personality, interests, knowledge, capacity, difficulties level and advances. It functions as a part of a collective teaching-learning process. The factors influencing in personality's formation play an important role in this process, especially the school. As an institution, the school should play a role of higher importance in forming new generations, but to play this role a combined work with the tutor of the practical area is needed because the tutor is a main piece in the performance of the future professional. In Cuba, in the conditions of the professional training, tutors are pedagogues in exercise of their profession. Due to the importance of the tutor and the role he/she should play in the professional practice for a correct contribution to the training of future health technologists, this article had the purpose of explaining the importance they have in the education at work. Several aspects are approached that are of great interest for the sake of tutors´ performance, related with their practical work including values formation (AU).

Influencia de los determinantes sociales en la salud del primer molar permanente / Influence of the social determinants in the first permanent molar health

Introducción: el proceso salud enfermedad depende de múltiples y complejas condiciones y no se rige solamente por las leyes conocidas de las ciencias naturales, sino que abarca también influencias psicológicas, socioeconómicas y ambientales. Estas son consideradas determinantes sociales de salud. Los factores causales que clínicamente producen la caries están bien identificados, pero no los determinantes socialesos a su prevalencia y menos asociados al primer molar permanente, considerado por diferentes autores como llave de la oclusión. Objetivo: determinar la salud del primer molar permanente, relacionado con algunos determinantes sociales de la salud en escolares de 11 a 16 años de edad. Materiales y métodos: para ello se decidió realizar una investigación observacional descriptiva prospectiva y transversal con el objetivo de determinar la salud del primer molar permanente, relacionado con algunos determinantes sociales de la salud en escolares de 11 a 16 años de la Escuela Secundaria Básica “Fermín y Yolanda” del municipio Unión de Reyes de septiembre 2014 de a abril de 2015. Resultados: se encontró que la mayoría de los adolescentes eran del sexo femenino, y tenían entre 13 y 14 años de edad. La mayoría de las familias de los adolescentes eran disfuncionales. De las barreras para conductas saludables estudiadas, la que más incidió fue la ingestión de alimentos que expenden alrededor de la escuela con el 95,3%. Conclusiones: a pesar de estos resultados el 60,7% de los molares permanentes eran saludables(AU).

Introduction: the health-disease process depends on multiple and complex conditions and it is not only ruled by the acknowledged laws of the natural sciences. It also includes psychological, socioeconomic and environmental influences. These are considered health social determinants. The causal factors clinically producing caries are well identified, but the social determinants related with its prevalence are not, less those associated to the first permanent molar considered by several authors as the key of the occlusion. Aim: to determine first permanent molar health related with several health social determinants in students aged 11-16 years. Materials and methods: a cross-sectional, prospective, descriptive and observational research was carry out with the aim of determining the health of the first permanent molar that is related with several health social determinants in students aged 11-16 years of the Basic Secondary School (Junior High School in the United States) “Fermin y Yolanda”, of the municipality Unión de Reyes from September 2014 to April 2015. Outcomes: most of the teenagers were females ones, aged 13-14 years. Most of their families were dysfunctional. From the studied barriers for healthy behaviour, the one with more incidences was the intake of food sold near the school with 95.3 %. Conclusions: in spite of these results, 60.7 % of the permanent molars were healthy (AU).

Estado de salud de primeros molares permanentes en adolescentes. Secundaria Básica Luis Pérez Lozano. Cienfuegos / First permanent molars´ health status in adolescents. Secondary School Luis Pérez Lozano. Cienfuegos

Introducción: el conocimiento del estado de salud bucal de la población escolar resulta una premisa indispensable para el desarrollo de una correcta planificación, organización y control de la atención estomatológica. Objetivo: determinar el estado de salud de los primeros molares permanentes en estudiantes de la Secundaria Básica “Luis Pérez Lozano”, del Área 7, Cienfuegos, de enero a diciembre de 2015. Materiales y Métodos: estudio observacional-descriptivo en un universo constituido por 197 niños de 7mo grado. El muestreo fue bietápico, combinando aleatorio, estratificado, proporcional y simple. Los datos se obtuvieron a través del examen bucal. Se tuvieron en cuenta las variables edad, sexo, estado de salud, y ubicación de los molares afectados. Resultados: el mayor porcentaje de primeros molares permanentes cariados correspondió al primer molar mandibular derecho e izquierdo para 11,9 % en el sexo masculino y el sexo femenino con primer molar permanente izquierdo para 11,6 %. Las obturaciones de los primeros molares mandibulares izquierdo predominó con un 16,6 % en el masculino y el mandibular derecho con un 13,9 % en las féminas. El mayor número de molares permanentes perdidos resultó en los inferiores, mandibular izquierdo en las niñas para 9,3 % y el molar mandibular derecho en los varones (7,1 %). Ambos sexos igualmente afectados con diferencia porcentual del 1%. El índice de Cluné obtuvo que los molares sanos para el sexo masculino representan 52,3 % y 53,4 % del femenino. Conclusiones: El estado de salud de los primeros molares permanentes en general se clasifica de regular pues existe un número considerable de afectados (AU).

Introduction: the knowledge of the school population´s oral health is a necessary premise for carrying out a correct planning, organization and control of the dental care. Objective: to determine the health status of the first permanent molars in students of the secondary school “Luis Pérez Lozano” of the health area 7, Cienfuegos, from January to December 2015. Materials and methods: an observational, descriptive study applied in a universe of 197 seventh-grade children. The sampling was two-staging, combining the randomized, stratified, proportional and simple sampling. The sample was obtained through the oral examination. The variables taken into account were age, sex, health status, and location of the affected molars. Results: the higher percentage of carious permanent first molars corresponded to the right and left mandibular first molar for 11,9 % in male sex and to the first left permanent molar in female sex with 11,6 %. The fillings of the first left mandibular molars predominated with 16,6 % in the male sex, and the right mandibular one in women with 13,9 %. The highest number of lost permanent molars was found among the lower ones, the left mandibular in girls (9,3 %) and the right mandibular in boys (7,1 %). Both sexes were equally affected, with a 1 % percent difference. The Clune’s index showed that healthy molars are 52,3 % for the male sex and 53,4 % for the female sex. Conclusions: in general, the first permanent molars´ health status is classified as regular because there is a substantial number of carious ones (AU).

Avaliação da mineralização dos segundos molares inferiores como parâmetro para a classificação da idade biológica / Evaluation of the mineralization of permanent second molars as a parameter to classify the biological age of the individual

O presente trabalho teve como objetivo avaliar se a mineralização dos segundos molares inferiores permanentes pode ser usado como parâmetro para classificar a idade biológica do indivíduo. A amostra foi constituída por 129 radiografias panorâmicas, sendo 71 indivíduos do sexo feminino e 58 indivíduos do sexo masculino, na faixa etária de 7 anos à 12 anos e 1 mês. Para a análise da mineralização dental foi utilizada a tabela proposta por Nolla (1960). Os resultados da análise foram documentados numa planilha do programa Microsoft Excel 2010 contendo o nome completo, data de nascimento, data da tomada radiográfica, idade em anos e meses, número do prontuário, estágio de Nolla (1960) lado direito e lado esquerdo. Foi realizada a análise estatística (Mann-Whitney, Wilcoxon e correlação de Spearman) e pôde-se concluir que na amostra estudada não foi encontrado dimorfismo sexual, que a mineralização dentária ocorre de forma similar do lado direito e esquerdo, e que a mineralização dos segundos molares inferiores permanentes podem ser usadas como parâmetro para estimar a idade biológica e cronológica de um indivíduo.(AU)

This paper aimed to evaluate if the mineralization of permanent second molars can be used as a parameter to classify the biological age of the individual. The sample was composed of 129 panoramic radiographs, being 71 females and 58 males, aged 7 years and 12 years and 1 month. For the analysis of dental mineralization it was used a table proposed by Nolla (1960) with X-rays on the negatoscope (light box). The analysis results were documented in a Excel spreadsheet containing the full name, date of birth, date of the radiographic procedure, age in years and months, medical record number, stage of Nolla (1960) right and left side. Performed a statistical analysis, we concluded in our survey that the tooth mineralization occurs similarly in the right and left side, there is a certain precocity when compared to chronological age and the stage of mineralization in females compared to males. We also conclude that within the same chronological age, girls and boys have different mineralization stages, indicating that the dental mineralization can be used to identify the biological age, and the same is poorly correlated with chronological age.(AU)

Importancia del primer molar permanente y consecuencias clínicas de su pérdida en edades tempranas del desarrollo / Importance of the first permanent molar and clinical consequences of its loss at early developmental stages

El primer molar permanente es la undiad más importante de la masticación y es esencial en el desarrollo de una oclusión funcionalmente deseable. La pérdida de este molar en un niño puede conducir a cambios en las arcadas dentarias que se perpetúan a lo largo del tiempo. Si no se toman medidas preventivas o correctivas apropiadas, podrán encontrarse: disminución en la función local, desviaciones de las piezas dentarias, extrusión de la pieza antagonista y trastornos de las articulaciones temporomandibulares, entre otras alteraciones. El presente artículo pretende evidenciar el protagonismo del primer molar permanente en la cavidad bucal y las consecuencias negativas que derivan de su ausencia. Además, deja entrever las necesidades de conocimiento por parte del odontólogo en los cuidados preventivos de dichas piezas dentarias y sobre la existencia de posibles tratamientos al momento de una pérdida inminente.

Segmented arch or continuous arch technique? A rational approach

This study aims at revising the biomechanical principles of the segmented archwire technique as well as describing the clinical conditions in which the rational use of scientific biomechanics is essential to optimize orthodontic treatment and reduce the side effects produced by the straight wire technique.

O objetivo desse trabalho é revisar os princípios biomecânicos da técnica do arco segmentado, bem como descrever situações clínicas onde o uso racional da biomecânica científica é fundamental na otimização do tratamento ortodôntico e eliminação dos efeitos colaterais da abordagem com arco contínuo.

Análise fotoelástica da distribuição de tensões nos segundos molares inferiores geradas por diferentes mecânicas de verticalização / Photoelastic analysis of stress distribution in lower second molars caused by several uprighting mechanics

A verticalização de molares inferiores é indicada quando ocorre inclinação mesial dos segundos molares, atribuídas à ausência do primeiro molar. Existem inúmeras metodologias para realização de tal movimento. O objetivo do estudo foi analisar e comparar in vitro, por meio de fotoelasticidade, a distribuição de tensões nos segundos molares inferiores geradas por diferentes métodos de verticalização. Foram avaliados quatro modelos com as seguintes mecânicas: mini-implante, cantiléver, mola em T e mola aberta. As regiões do segundo molar selecionadas para avaliação foram: cervical da raiz mesial, apical da raiz mesial, cervical da raiz distal e apical da raiz distal. A resultante das forças aplicadas foi aferida por meio da quantificação das franjas isocromáticas. Os valores de franjas foram descritos com uso de média e desvio padrão e verificada a concordância/reprodutibilidade entre as avaliações com uso do coeficiente de correlação intraclasse com os respectivos intervalos com 95% de confiança e calculadas as medidas de repetibilidade. Os diferentes tipos de mecânicas foram comparados com uso de teste não paramétrico e quando o teste apresentou significância estatística foram realizadas comparações múltiplas não paramétricas para medidas pareadas com o intuito de verificar entre quais tipos de mecânicas ocorreram diferenças nas ordens das franjas...

Lower molars uprighting is indicated when mesial inclination of second molars occurs due to the lack of first molars. There are many methodologies to perform such movement. The goal of this research study was to in vitro analyze and compare, by means of photoelasticity, the strain distribution in lower second molars caused by several uprighting methods. Four models with the following mechanics have been evaluated: miniscrews, cantilever, T- loop spring and open coil spring. The second molar areas selected for the evaluation were the following ones: mesial-cervical area, apical area of the mesial root, distal-cervical and apical areas of the distal root. The resultant of forces applied was measured by quantifying isochromatic fringes. The fringe values were described using the mean and the standard deviation values and the agreement/reproducibility among the assessments were verified applying the intraclass correlation coefficient in the respective intervals with 95% confidence. Repeatability measures were calculated. The different types of mechanics were compared applying the nonparametric test and, when the test showed statistical significance, nonparametric multiple comparisons were carried out for paired measurements, aiming at checking in which mechanics fringe differences occur. Values statistically differed among the types of mechanics applied (p < 0.05), except in the distal-cervical area, in which the values were statistically the same for the four types of mechanics (p = 0.112). In the technique using miniscrews, the highest strain values were found in the distal-cervical area, followed by the apical area of the mesial root and the apical area of the distal root...

Avaliação das tensões geradas por prótese obturadora maxilar implanto-retida por meio da análise de elementos finitos / Avaliation of stresses generated by the maxillary obturator prosthesis implant-retained by the finite element analysis

Neste estudo avaliou-se o comportamento biomecânico de próteses obturadoras maxilares Classe Ib, II e III de Okay retidas por implantes, observando as tensões geradas no tecido ósseo e gengivo-mucoso maxilar. A Análise de Elementos Finitos foi realizada empregando-se um modelo digital desenvolvido a partir de uma tomografia computadorizada de um indivíduo adulto. Utilizou-se o programa Rhinoceros® versão 4.0 SR9 para gerar o modelo maxilar BioCAD 3D, incorporando-se os modelos CAD dos implantes e UCLAS. Os implantes foram posicionados de acordo com cada modelo: Modelo 1 (Classe Ib de Okay): 6 implantes posicionados em regiões de caninos e incisivos laterais bilateralmente e em região de segundo premolar e primeiro molar esquerdos onde foram utilizados 4 clipes para o sistema de retenção barra/clipe; Modelo 2 (Classe II de Okay): 4 implantes posicionados em região de canino, incisivo lateral, segundo premolar e primeiro molar esquerdos, com 3 clipes; Modelo 3 (Classe III de Okay): 2 implantes posicionados em região de segundo premolar e primeiro molar esquerdos, com 2 clipes. A malha de elementos finitos foi gerada pelo programa Ansys®, tendo sido aplicada uma força de 80 N na plataforma oclusal, e de 35 N na plataforma incisal. Foi realizada uma análise qualitativa, correspondente à escala de tensão máxima principal, com valores quantitativos expressos em MPa. O deslocamento da prótese obturadora na região sem suporte ósseo aumentou em função da diminuição da área de suporte ósseo, do número de implantes e de clipes; a mucosa gengival, o osso cortical e o osso medular sofreram tensões de tração e de compressão que aumentaram em função da diminuição da área de suporte ósseo, do número de implantes e de clipes. Concluiu-se que quanto maior a perda da área de suporte ósseo em uma maxilectomia, maiores serão as forças de tensão e de compressão geradas pelo sistema de retenção barra/clipe nos tecidos remanescentes e maior será a tendência para o deslocamento da prótese.

Patients submitted to maxillectomy due to oral cancer shall be rehabilitated by means of obturator prosthesis in order to achieve a better quality of life. This study evaluated the biomechanics of implant-retained obturator prostheses analyzing the stress on maxillary osseous and gingivo-mucosal tissues. Finite elements analysis was developed using a 3D digital model based on a computed tomography of an adult man. Files were processed by Software Rhinoceros®, v4.0 SR9 and generated a maxillary BioCAD 3D model, which incorporated the CAD models of the implants and UCLAS. The implants were located considering: Model 1 (Okay Class Ib) - 6 implants in the areas of canines and lateral incisors and in the areas of left second premolar and molar, retention system bar/4 clips; Model 2 (Okay Class II ) - 4 implants located in the areas of canine, lateral incisor, left second premolar and first molar, retention system bar/3 clips; Model 3 (Okay Classe III) - 2 implants inserted in the left second premolar and first molar, retention system bar/2clips. The finite elements mesh was generate using Software Ansys®. A force of 80 N was applied to the occlusal platform and, at the same time, a force of 35 N was applied to the incisal platform of the obturator prosthesis. Results considered a qualitative analysis, based on the scale of maximum principal stress, and a quantitative analysis, when values were expressed in MPa. The dislodgement of the obturator prosthesis in the area with no osseous support increases as the area of the osseous support, the number of implants and clips diminish; the tensile and compressive stress in the gingival mucosa, the cortical and the alveolar bone increase as the osseous support, the number of implants and of clips diminish. The larger the area without osseous support, the higher the tensile and compressive stress in the remaining tissues and greater the displacement of the prosthesis.

Articaína com hialuronidase em infiltração bucal em primeiro molar inferior / Articaine and hyaluronidase in buccal infiltration on inferior first molar

O índice de sucesso em anestesia infiltrativa em molar inferior é muito baixo, o que justifica a técnica de bloqueio do nervo alveolar inferior mesmo essa sendo mais dolorida. Recentes estudos demonstraram que a anestesia infiltrativa com articaína apresentou maior índice de sucesso do que com a lidocaína, porém, ainda não foi possível evitar falha anestésica. Para aumentar o índice de sucesso dessa técnica vislumbra-se a utilização da enzima hialuronidase como fator de difusão do anestésico local e aumentar a eficácia clínica. O estudo avaliou se a hialuronidase à 150 UTR injetada imediatamente após a articaína infiltrativa em primeiro molar inferior seria capaz de prolongar a duração da anestesia local (AL) na polpa e na gengiva, reduzir a latência de ação, aumentar o seu índice de sucesso anestésico e se o uso da H aumenta a dor do local. Participaram 28 pacientes ASA I e II que apresentavam necessidade de restauração em 2 primeiros molares inferiores. Estes foram alocados em 2 grupos: (1º) 28 pacientes receberam anestesia com articaína 4% associada à epinefrina em seguida era injetada H 150 UTR/ml. (2º) Idêntico ao primeiro grupo, porém utilizando placebo (solvente da hialuronidase) de forma duplo-cego e boca dividida. A latência e a duração na polpa foram avaliadas com estímulo elétrico na face vestibular do primeiro molar inferior, a cada 2 e 10 min, respectivamente. Para gengiva vestibular, utilizou-se estímulo mecânico (picada). Para análise do índice de dor utilizou-se escala numérica de dor (1 a 5) em 3 tempos analisados. A presença da hialuronidase não melhorou o índice de sucesso, não diminuiu o tempo de latência gengival, não aumentou a duração de ação pulpar nem a gengival e não aumentou os níveis de dor, mas houve diminuição da latência gengival do grupo H 150 se comparado a todos os demais. Nas condições experimentais, esta concentração de H não melhora a eficácia clínica.

The success rate in infiltrative anesthesia in lower molar is very low, which explains the technique of inferior alveolar nerve block even this is more painful. Recent studies have shown that infiltrative anesthesia with articaine had a higher success rate than with lidocaine, however, has not been possible to avoid failure of anesthesia. To increase the success rate of this technique envisages the use of the enzyme hyaluronidase as a factor of local anesthetic spread and increase clinical efficacy. The study evaluated whether the 150 TRU/ml to hyaluronidase injected immediately after articaine infiltration in the first molar would be able to prolong the duration of local anesthesia (LA) in the pulp and gums and reduce latency of action, increase your success rate of anesthetic and the use of H increases the pain site. Participated in 28 ASA I and II patients who had need of restoration in two mandibular first molars. These were divided into 2 groups: (1) 28 patients received anesthesia with 4% articaine associated with epinephrine was then injected H 150 TRU/ml. (2) Same as the first group, but using placebo (hyaluronidase solvent) in a double-blind, split-mouth. The latency and duration of the pulp electrical stimulation were evaluated on the buccal of the mandibular first molar, every 2 and 10 min, respectively. For vestibular gingiva, we used mechanical stimulation (pinprick). To analyze the level of pain was used numeric pain scale (1-5) at 3 times analyzed. The presence of hyaluronidase didnt improve the success rate was not reduced latency time gum didnt increase the duration of action or the pulp and gum didnt increase levels of pain, but there was reduced latency gum group compared to H 150 all others. Under the experimental conditions, this concentration of H not improved clinical efficacy.

Three-dimensional finite element analysis of the stress distribution pattern in the design modifications of U-shaped palatal major connector.

Background: The U-shaped maxillary major connector is considered to be the least-desirable design by many prosthodontists as it lacks rigidity, which is a primary requisite for a major connector. Aims and Objectives: Design modifications in the U-shaped palatal major connector are desired because it lacks rigidity. The study also aimed to determine the best design when a U-shaped palatal major connector is indicated for clinical use. Materials and Methods: The normal design and the design-modified models (modification 1, 2, 3, 4) were loaded at the functional cusps of the premolars and the molars with a magnitude of 200 N, 250 N and 300 N at angulations of 60 o and 90 o on both sides of the maxillary arch. Results for each loading were obtained as stress distribution colored images and numerical values were recorded. A three-dimensional finite element analysis study of the design-modified models was performed using two finite element softwares, namely PRO-E and IDEAS. Results: The least stress value of 7.86 Megapascals (MPa) at 200 N, 60 o was recorded for the double-thickness design, followed by design 1, which was 8.03 MPa. The least stress value for the palatal mucosa and ligament was provided by design modification 1 (0.5 mm-thick U-shaped connector, 9 mm anteroposteiorly, 14.6 mm laterally), which was 9.78 MPa and 2.98 MPa, respectively. Conclusion: The double-thickness group exhibited the least internal stress for the U-shaped major connector. However, it delivered the greatest stress to the palatal mucosa and the periodontal ligaments.

Anatomical evaluation of some morphological abnormalities related to periodontal diseases

The presence of some dental abnormalities as a predisposal factor to installation of localized periodontal alterations. The present study was to evaluate the frequency of development abnormalities present on a sample of molars that may predispose to occurrence and progression of periodontal disease. Two hundred and seventy seven molars (141 maxillary and 136 mandibular molars) were selected for this study. The evaluations were performed by two examiners together who was trained and calibrated for the study. All measurements were made by direct visualization with a magnifying glass. The following clinical parameters were measured: Enamel cervical projections; Root trunk: in the three different extensions (<3 mm, >3 mm and <6 mm, >6 mm); Enamel pearls: presence (1) or absence (0). The anatomic observations were made on four surfaces of the tooth: mesial, distal, vestibular and palatal/lingual. Descriptive statistics and percentage distribution were performed. A total of 130 molars showed at least some degree of enamel cervical projection and the most frequent score was the degree 1, according to Masters and Hoskins classification. Fifteen teeth presented enamel pearls and the root trunk was more evident on the group with variation from 3 to 6 mm of extension, observed in 64 teeth. It can be concluded that the presence of development abnormalities is a frequent finding in molars and it has to be taken into consideration during periodontal examination and therapy.

Sequential expressions of Notch1, Jagged2 and Math1 in molar tooth germ of mouse

The Notch signaling pathway is an evolutionary conserved mechanism that plays an important role in cell-cell communication and cell fate in a wide range of tissues. The mammalian family of Notch receptors consists of 4 members: Notch1/2/3/4. The Notch ligand family consists of 5 members: Delta1/3/4 and Jagged1/2. Math1 encodes a murine Basic helix-loop-helix (bHLH) transcription factor that acts as positive regulator of cell differentiation. Recently, links between Notch and Math1 pathways were demonstrated in various tissues. Expression of Notch1, Jagged2 and Math1 were analyzed in the mouse molar tooth germ during embryonic stage (E) 13 and E15 and during postnatal stage (PN) 1, PN3, PN5, PN10 and PN14 by using in situ hybridization. Positive Notch1 expression was found at the tooth bud during embryonic stages, but its expression was absent from the basal cells in contact with the dental mesenchyme. Jagged2 and Math1 were strongly expressed in differentiated ameloblasts and odontoblasts and Math1 strong expression was even maintained until PN14 stage. Math1 showed the strongest expression. Our results suggest that the Notch1 signaling pathway through Jagged2 could be importantly related to Math1, directing the process of odontogenesis toward cell differentiation.

Eruption age of permanent mandibular first molars and central incisors in the south Indian population.

OBJECTIVE: The existing eruption schedules for permanent and deciduous dentition are based on studies in the Western population. Since Indians differ from Westerners racially, genetically, and environmentally, these studies fail to provide relevant guidance on the eruption schedule in the Indian population. This study aims at determining the eruption pattern of permanent mandibular molars and central incisors in the south Indian population. MATERIALS AND METHODS: 10,156 apparently healthy Indian children in the age-group of 6-9 years were examined with mouth mirror and probe under adequate illumination for the status of the eruption of the permanent mandibular first molar and permanent mandibular central incisor. Pearson's Chi-square test with Yates' continuity correction was used to calculate the P -value for comparison of proportion between girls and boys. The values obtained in our study were compared with the standard values. The Z-test with continuity correction was used to calculate the P -value. RESULTS: As per our study, the permanent mandibular first molars and central incisors erupted one to two years later compared to the values reported in Westerners. The earlier eruption of the permanent mandibular first molars compared to the permanent mandibular central incisors, as well as the earlier eruption of both the teeth in girls compared to boys, were in accordance with the existing literature. CONCLUSION: The eruption age reported by us may form a standard reference for eruption age in Indians.

Etapas de maduración y erupción de incisivos y molares permanentes, en la dentición mixta / Maturation and eruption stages in permanent incisors and molars, in the mixed dentition

El objetivo de nuestro trabajo fue analizar la maduración de los primeros molares e incisivos centrales inferiores (ICI) permanentes y etapas de erupción de los primeros molares superiores e inferiores (1er MS, 1er MI) permanentes del lado izquierdo, en la dentición mixta temprana, en niños de ambos sexos. Materiales y métodos: se estudiaron 170 ortopantomografías de niños de 6 años +- 9 meses, divididos en: grupo 1 < de 6 años (n=78) y grupo II de 6 años o más (n=92). Resultados: los 1ros MI se encontraban en el estadio raíz casi completa en el grupo II: en varones 62,9 por ciento y en mujeres 71.9 por ciento. Los ICI en el grupo II mostraban dos tercios de la raíz completa en un 60 por ciento de varones y en un 43.9 por ciento de mujeres. Con respecto a la erupción del 1er MS en el grupo II en varones se encontraba erupcionado en un 40 por ciento y en un 45.6 por ciento en mujeres, mientras que el 1er MI en la misma etapa del grupo II en varones fue 37.1 por ciento y en mujeres fue 64.9 por ciento. Conclusiones: la maduración del molar inferior antecede a la de los incisivos inferiores permanentes. Las niñas presentan un porcentaje mayor de primeros molares erupcionados

Levantamento sobre a erupção precoce dos primeiros molares permanentes em crianças abaixo de 6 anos de idade e sua prevalência de cárie / Epidemiologic study of early eruption of the first permanent molars with children under six years old and their caries prevalence

Esta pesquisa visa fornecer dados à Odontopediatria quanto ao período de erupção dos primeiros molares permanentes em crianças com idade abaixo dos 6 anos (3, 4 e 5 anos), bem como informar aos pais a época e a importância desses dentes e os cuidados que devem receber durante sua erupção. Trabalhou-se com uma amostra de 600 crianças abaixo de 6 anos, obtidas na pré-escola e creches da periferia de Ribeirão Preto/SP/Brasil. Verificou-se que 123 (20,5 por cento) das 600 crianças analisadas apresentavam primeiros molares permanentes erupcionados em diferentes graus, constituindo um total de 337 dentes, sendo que 61 deles já apresentavam lesão de cárie. Os resultados permitem concluir que é bastante significativo o número de crianças abaixo de 6 anos (3, 4 e 5 anos) pesquisadas que já possuem os primeiros molares permanentes erupcionados; muitos destes já apresentam lesão de cárie, o que justifica a atenção da Odontologia no sentido de monitorizar precocemente a erupção desses dentes, bem como instituir medidas preventivas de cárie