Actualización del análisis de los movimientos mandibulares a través de articulografía electromagnética / Updating the analysis of mandibular movements through electromagnetic articulography

El objetivo de registrar los movimientos mandibulares es obtener parámetros relevantes que permitan evaluar el estado de la articulación temporomandibular (ATM) y de los músculos involucrados en la masticación. El movimiento mandibular se debe a un conjunto complejo de rotaciones y traslaciones tridimensionales realizadas por la ATM, limitado por los ligamentos y las superficies articulares de estas, y por la morfología y la alineación de los dientes, cuando la mandíbula se desplaza sobre estos límites, se llaman movimientos bordeantes mandibulares. El objetivo de este artículo es realizar una descripción actualizada de los movimientos mandibulares a través de articulografía electromagnética. Los movimientos mandibulares bordeantes se clasifican según el plano del espacio en que se muevan, de esta manera tenemos movimientos bordeantes en el plano sagital, en el plano horizontal y el plano frontal, y en cada plano dibujan un polígono distinto, llamados polígonos de Posselt. Estos polígonos pueden ser registrados mediante Articulografía electromagnética, gracias a esta tecnología también se pueden extraer algunos parámetros interesantes, como por ejemplo: la trayectoria total recorrida por la mandíbula al describir cada polígono, rangos de desplazamiento en cada plano, área total de cada polígono de Posselt. La apertura mandibular se mide como la distancia entre los márgenes incisales de los incisivos centrales superiores e inferiores en apertura máxima más la sobremordida. El análisis de esta es una parte importante del examen clínico en odontología, ya que una apertura limitada puede ser resultado de trastornos en la articulación temporomandibular, fibrosis oral submucosa, enfermedad reumática o trauma facial. Las mediciones tridimensionales que se obtienen gracias a la Articulografía electromagnética, son apropiados para determinar los rangos normales de apertura, su exactitud permite la realización de investigaciones en el área, abriendo un amplio campo en el análisis de los movimientos mandibulares.

SUMMARY: The objective of recording mandibular movements is to obtain relevant parameters that allow the evaluation of the state of the temporomandibular joint (TMJ) and of the muscles involved in mastication. Mandibular movement is due to a complex set of three-dimensional rotations and translations performed by the TMJ, limited by the ligaments and their articular surfaces, and by the morphology and alignment of the teeth, when the mandible moves over these limits, they are called mandibular border movements. The aim of this article is to provide an updated description of mandibular movements through electromagnetic articulography. Mandibular border movements are classified according to the plane of space in which they move, thus we have border movements in the sagittal plane, in the horizontal plane and the frontal plane, and in each plane they draw a different polygon, called Posselt polygons. These polygons can be recorded by electromagnetic articulography, thanks to this technology some interesting parameters can also be extracted, such as: the total trajectory covered by the mandible when describing each polygon, displacement ranges in each plane, total area of each polygon of Posselt. Mandibular opening is measured as the distance between the incisal edges of the upper and lower central incisors at maximum opening plus the overbite. The analysis of mandibular opening is an important part of the clinical examination in dentistry as a preliminary evaluation, since limited opening can be the result of temporomandibular joint disorders, submucous oral fibrosis, rheumatic disease or facial trauma. The three-dimensional measurements that are obtained thanks to the electromagnetic Articulography, are appropriate to determine the normal ranges of opening, its accuracy allows the realization of investigations in the area, opening a wide field in the analysis of mandibular movements. Analysis of mandibular opening is an important part of the clinical examination in dentistry, since limited opening can be the result of temporomandibular joint disorders, oral submucous fibrosis, rheumatic disease, or facial trauma. Analysis of mandibular opening is an important part of the clinical examination in dentistry, since limited opening can be the result of temporomandibular joint disorders, oral submucous fibrosis, rheumatic disease, or facial trauma. The three-dimensional measurements that are obtained thanks to the electromagnetic Articulography, are appropriate to determine the normal ranges of opening, its accuracy allows the realization of investigations in the area, opening a wide field in the analysis of mandibular movements.

Research progress in effect of chewing-side preference on temporomandibular joint and its relationship with temporo-mandibular disorders / 浙江大学学报·医学版

Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.

Modelo lineal vs. vectorial: estimación del movimiento mandibular y trabajo mecánico / Linear vs. vector model: estimation of mandible motion and mechanical work

Objetivo: Determinar los momentos de fuerza del haz superficial del masetero (SMH) obtenidos por modelos lineal y vectorial. Métodos: Investigación comparati-va in silico. Se obtuvo la fuerza del SMH con dinamó-metro en 12 pacientes varones adultos jóvenes para calcular el momento de la fuerza y trabajo mecánico a través de simulaciones en JAVA+ con NetBeans8.2. La descomposición de la fuerza fue F.cos α(x,y) y F.cos α(x,y,z) en el modelo lineal y vectorial respectivamen-te. Los momentos de fuerza fueron comparados por ANOVA (p<0,05). Resultados: La fuerza del SMH unila-teral obtenida con dinamómetro (2,5±0,1N) no difirió significativamente del modelo lineal (2,6±0,05N), pero difirió (p<0,001) del vectorial: 1,7, 2,2, 4,2N en x,y,z (general 2,7±0,02N). El momento medio de la fuerza en el modelo vectorial fue -17,9, -15,5, +14,3N.m-2, apuntando a la inclinación mandibular en el eje lateral en dirección caudal anterior, movimiento de inclina-ción en el eje lateral en la dirección cráneo-medial, e inclinación en el eje craneal en la dirección lateral-an-terior. El modelo lineal mostró momento de fuerza de 13,5N.m-2 apuntando un movimiento traslacional en dirección caudal-craneal en el eje anterior-posterior y menor trabajo mecánico del SMH (p=0,012). Con-clusión: Los modelos vectoriales son más eficientes proporcionando datos detallados para estimar los momentos de fuerza y el trabajo mecánico del SMH, y deben incluirse en los algoritmos de cálculo utilizados por dinamómetros (AU)

Objective: to determine the moments of force exerted by the superficial masseter head (SMH) obtained through linear models and vector ones. Methods: comparative in silico research. Data of SMH force obtained with dynamometer in 12 young adult male patients was used to calculate the moment of the force and mechanical work through simulations in JAVA+ performed with NetBeans8.2. Force decomposition was F.cos α(x,y) and F.cos α(x,y,z) in the linear and vector model respectively. The moments of force were compared by ANOVA (p<0.05). Results: Dynamometrical unilateral SMH force (2.5±0.1N) did not differ significantly from the linear model (2.6±0.05N), but differed (p<0.001) from the vector model: 1.7, 2.2, 4.2N on x,y,z (overall 2.7±0.02N). The mean moment of the force in the vector model was -17.9, -15.5, +14.3N.m-2, pointing to mandible's inclination on the lateral axis in anterior-caudal direction, inclination movement on the lateral axis in the cranio-medial direction and inclination on the cranial axis in the lateral-anterior direction. The linear model showed a moment of force of 13.5N.m-2 pointing to translational motion on caudal-cranial direction on the anterior-posterior axis and lower SMH mechanical work (p=0,012). Conclusion: Vector models are more efficient to provide detailed data to estimate the moments of force and mechanical work of SMH and should be included in the calculation algorithms used by dynamometers (AU)

Microtornillos como método de control vertical en desprogramación muscular / Vertical control with miniscrews in muscular deprogramming treatment

Una de las consecuencias de la desprogramación neuromuscular es la rotación mandibular en sentido horario, evidenciando el punto prematuro de contacto y aumentando la dimensión vertical del paciente. En pacientes clase II con componente vertical, es un problema realizar este tipo de tratamiento, ya que por lo general este efecto de posterorrotación mandibular hace el perfil más convexo, y en algunos casos genera mordida abierta anterior, la cual se debe corregir posteriormente con el tratamiento de ortodoncia, cirugía o prótesis, lo que alarga el tiempo total de tratamiento por la necesidad de control vertical. El presente caso se trata de una mujer de 45 años de edad, dolicofacial, con tendencia a mordida abierta, mordida dual, sobremordida vertical y horizontal disminuidas, motivo de consulta dolor articular, el cual no le permite continuar con sus labores diarias, el tratamiento realizado fue desprogramación neuromuscular con un guarda oclusal inferior con el propósito de aliviar sintomatología articular y control vertical con microtornillos palatinos previo a tratamiento ortodóncico (AU)

One of the effects of the neuromuscular deprogramming treatment is the mandibular clockwise rotation, making the light premature occlusal contact more evident and increasing the patient vertical dimension. In Class II patients with vertical component is difficult to treat them due to profile worsening as an effect of the clockwise rotation creating in some patient's anterior open bite, this has to be corrected later in treatment with orthodontic intrusion, surgery or prosthodontic treatment, increasing the total time of treatment with the vertical control necessity. This case report is a 45 years old patient, dolichofacial, with anterior open bite tendency, dual bite, decreased overjet and overbite, her chief complaint was temporomandibular joint dysfunction which dont allow her to do her daily duties, the treatment for her was neuromuscular deprogramming splint for the temporomandibular joint pain, and vertical control with temporary anchorage devices (miniscrews) before the orthodontic treatment (AU)

Análisis tridimensional de movimientos mandibulares bordeantes en participantes dentados totales / Three-dimensional analysis of mandibular border movements in fully dentate participants

Las articulaciones temporomandibulares y la musculatura asociada, permiten que la mandíbula se desplace en los tres planos del espacio (sagital, frontal y horizontal), de esta forma la mandíbula puede realizar movimientos mandibulares complejos. Hace varias décadas que los movimientos bordeantes mandibulares son estudiados, sin embargo, en un principio los estudios se realizaban en dos dimensiones (2D). En la actualidad, gracias al articulógrafo electromagnético (EMA) 3D es posible realizar el estudio de la cinemática mandibular en tres dimensiones (3D). El objetivo del siguiente estudio es analizar los movimientos mandibulares bordeantes (sagital, frontal y horizontal), por medio de la articulografía electromagnética 3D. En el estudio, participaron 11 personas de 31,9 ± 5,7 años en promedio (mujeres 30,2 ± 2,9 y hombres 34,0 ± 7,8) completamente dentados de primer molar a primer molar, sin trastornos temporomandibulares ni tratamiento previo de ortodoncia. Los archivos fueron procesados mediante scripts, desarrolladas en MATLAB®. Entre los resultados más relevantes, se encontró diferencia estadística entre hombres y mujeres en relación al área Frontal del polígono de Posselt, y los resultados del área del polígono sagital de todos los participantes, fue mayor que en estudios previos.

The temporomandibular joints and associated muscles allow the mandible to move in the three planes (sagittal, frontal and horizontal), in this way the jaw can perform complex mandibular movements. For several decades, mandibular border movements have been studied. However, studies were initially carried out in two dimensions (2D). At the present time, it is possible to analyze mandibular kinematics in three dimensions (3D), with the 3D electromagnetic articulograph (EMA). The objective of the study is to evaluate the mandibular border movements (sagittal, frontal and horizontal), using 3D electromagnetic articulation. In this analysis, 11 subjects 31.9 ± 5.7 years of age on average, participated (women 30.2 ± 2.9 and men 34.0 ± 7.8) completely dentate patients, from first to first molar, with no temporomandibular disorders or orthodontic pretreatment. Files were processed using scripts, developed in MATLAB®. Among the most relevant results, a statistical difference was found between men and women in relation to the Frontal area of Posselt polygon, and results of the sagittal polygon area of all the participants were greater than those reported in previous studies.

Análisis cinemático de la masticación de una granola prototipo en contraste con la masticación de maní / Kinematic analysis of chewing by using a granola prototype and peanut

La masticación se ha estudiado desde diferentes puntos de vista, utilizando alimentos de prueba naturales y artificiales. La evidencia es escasa cuando se analizan alimentos a base de cereales, que van desde cereales para el desayuno hasta barras de granola. El investigar este tipo de alimentos, se vuelve importante para entender el comportamiento de la masticación frente a alimentos con diferentes composiciones y texturas, y como estas características pueden influir en el proceso masticatorio. Se analizó la masticación desde un punto de vista cinemático, en sujetos jóvenes dentados. El alimento de prueba utilizado fue granola prototipo y maní, este último se ha estudiado en sujetos con rehabilitación protésica y su consumo se recomienda en esta población. Se analizaron las características cinemáticas de la masticación como numero de ciclos, frecuencia masticatoria, velocidad de masticación de ascenso y descenso, y el área de masticación en los tres planos del espacio. Se relacionaron los movimientos masticatorios con los movimientos mandibulares bordeantes que conformaron el polígono de Posselt, este también se analizó en los tres planos espaciales. En todas las variables analizadas la granola presento valores mayores, excepto en el número de ciclos masticatorios, sólo se encontraron diferencias estadísticamente significativas (p= 0,03) al comparar la velocidad (ascenso y descenso) y el área de masticación en el plano horizontal.

Chewing has been studied from different points of view, using natural and artificial foods test. When analyzing cereal-based foods, from breakfast cereals to granola bars, the evidence is scarce. Investigate this type of food is important to understand the behavior of chewing, with foods of different compositions and textures, and how these characteristics can influence the chewing process. Chewing was analyzed from a cinematic point of view, in young subjects complete dental. The test food used was prototype granola and peanuts, last one has been studied in subjects with prosthetic rehabilitation and its consumption is recommended in this population. The kinematic characteristics of chewing were analyzed: number of cycles, chewing frequency, ascent and descent chewing speed, and the chewing area in the three planes of space. The masticatory movements were related to the bordering mandibular movements, that formed the Posselt polygon, which was also analyzed in the three spatial planes. In all the variables analyzed, granola showed higher values, except in the number of chewing cycles, only statistically significant differences (p = 0.03) were found when comparing speed (ascent and descent) and the chewing area in the horizontal plane.

Full term newborns in non-nutritive suction evaluationand their relation on feeding performance / Avaliação da sucção não nutritiva de recém-nascidos a termo e sua relação com o desempenho da mamada

Abstract Objectives: To investigate full term newborns suction pattern in non-nutritive suction and their feeding performance. Methods: An analytical descriptive study was carried out from November 2016 to March 2017, with 50 dyads mothers/newborns through the non-nutritive suction evaluation and a direct observation on the newborn's performance on feeding. The data were distributed through simple and relative frequencies (percentages) when categorical or by mean, maximum, minimum and the standard deviation when is continuous, discrete or ordinal. To evaluate the mean differences, the Student's t test was used with significance level of 5%. Results: There were significant differences among the newborn's mandible movement ("newborn's mouth slightly open" p=0,005), suction ("cheek strain during feeding" p<0,001) and dyad mother and newborn positioning ("breasts supported with fingers on the areola" p=0,041 and baby's neck or trunk turned" p=0,041). Conclusions: Newborns that presented changes in their mandible movement on the Non-Nutritive Suction (NNS) also presented difficulties in feeding. The newborn's knowledge on suction pattern through the NNS has proven to be an important strategy that may help identify possible difficulties during feeding.

Resumo Objetivos: investigar o padrão de sucção de recém-nascidos a termo na sucção não-nutritiva e sua relação com o desempenho destes na mamada. Métodos: estudo descritivo analítico, realizado de novembro de 2016 a março de 2017, com 50 díades mãe/recém-nascido, mediante avaliação da sucção não-nutritiva e observação direta do desempenho do recém-nascido na mamada. Os dados foram descritos por meio de frequências simples e relativas (percentuais) quando categóricas ou média, máximo, mínimo e desvio padrão quando contínuas, discretas ou ordinais. Para avaliar diferenças de média foi utilizado o teste T de Student com nível de significância de 5%. Resultados: houve diferenças significativas entre movimentação da mandíbula do recém-nascido e aspectos da pega ("boca do bebê pouco aberta" p=0,005), sucção ("esforço da bochecha durante a mamada" p<0,001) e posicionamento da díade mãe e recém-nascido ("mamas apoiadas com os dedos na aréola" p=0,041 e bebê com pescoço ou tronco torcidos" p=0,041). Conclusões: recém-nascidos que apresentaram alterações na movimentação da mandíbula na Sucção Não Nutritiva (SNN) tiveram também dificuldade na realização da mamada. O conhecimento do padrão de sucção do recém-nascido, através da avaliação da SNN mostrou-se como estratégia importante que pode auxiliar na identificação de possíveis dificuldades do recém-nascido durante a mamada.

Neurofisiología y bruxismo / Neurophysiology and bruxism

El bruxis mo muestra una fi siopatología compleja, donde se involucran señales aferentes y eferentes reguladas por el SNC a través de la expresión de neurotransmisores que repercute en una hiperactividad muscular disfuncional y eventualmente dañina. Para intentar comprender bruxismo desde sus particularidades neurofi siológicas, fue realizada una revisión bibliográfi ca en las bases de Medline y PubMed con el objetivo de establecer la relación entre neurotransmisores y el sistema neuromasticatorio, señalando las posibles alteraciones en su liberación que desencadenen irregularidades en los movimientos rítmicos de la mandíbula (rhythmic jaw Mmovement [RJM]) durante el sueño, inducidos por desórdenes en el sistema nervioso central, por trastornos psicológicos y psiquiátricos, drogadicción y prescripciones médicas, y en alguna medida a una respuesta reactiva a situaciones locales y cambios adaptativos. El funcionamiento masticatorio depende de la integración del aporte sensorial (aferente) de componentes como lo son el ligamento periodontal, músculos masticatorios, dientes y articulación temporomandibular, que puede ser perturbado; cuando alguna de estas partes sufre alteraciones en su integridad, infl amación o sobrecarga funcional o por alteraciones morfológicas, observándose una variedad de respuestas adaptativas y compensatorias (eferentes). En bruxismo esta información local es de relevancia menor, ya que este se rige por cambios centrales observados durante el sueño o bien alteraciones de infl uencia psicológica durante el bruxismo diurno. Consiguientemente, el bruxismo trae apareados cambios biológicos, emocionales y de conducta que repercuten en músculos mayores, preferentemente localizados en cabeza y cuello, ocasionando de manera secundaria numerosas alteraciones; particularmente en la región estomatognática, se observan diversos deterioros como daño de las mucosas, dolor miofascial y articular y atrición dental. La comprensión de los complejos procesos neurofi siológicos que determinan la aparición y persistencia de bruxismo puede ayudar a establecer estrategias de control y tratamiento (AU)

Bruxism shows a complex pathophysiology, where afferent and aff erent signals regulated by the CNS, through the expression of neurotransmitters with repercussion in dysfunctional and eventually harmful muscular hyperactivity. To try to understand bruxism from its neurophysiological peculiarities, a bibliographic review was carried out on the bases of Medline and PubMed, with the aim of establishing the relationship between neurotransmitters and the neuromasticatory system, pointing out the possible alterations in their release that trigger irregularities in the rhythmic movements of the jaw (rhythmic jaw movement [RJM]) during sleep induced by disorders in the central nervous system, psychological and psychiatric alterations, drug addiction and medical prescriptions, and to some extent, a reactive response to local situations and adaptive changes. The masticatory functioning depends on the integration of the sensory input (aff erent) of components such as the periodontal ligament, masticatory muscles, teeth and temporomandibular joint, which can be disturbed when any of these parts suff er alterations in their integrity, infl ammation, functional overload or morphological alterations, observing a variety of adaptive and compensatory (efferent) responses. In bruxism, this local information is of minor relevance, since it is governed by central changes observed during sleep or changes in psychological infl uence during daytime bruxism. Consequently, bruxism brings with it biological, emotional and behavioral changes that aff ect major muscles, preferably located in the head and neck, causing in a secondary way many other alterations. Particularly in the stomatognathic region, several deteriorations are observed, such as mucosal damage, myofascial and joint pain and dental attrition. The understanding of the complex neurophysiological processes that determine the appearance and persistence of bruxism can help to establish control and treatment strategies (AU)

Systemic melatonin application increases bone formation in mandibular distraction osteogenesis

Abstract This study aimed to investigate the effects of different doses of systemic melatonin application on new bone formation during mandibular distraction osteogenesis (DO) in rats. Mandibular DO was performed on 30 adult female Sprague-Dawley rats, which were randomly divided into three groups: control group (CNT), melatonin dose 1 (MLT-D1), and melatonin dose 2 (MLT-D2). A five-day latent waiting period and a ten-day distraction phase followed the surgery. After the surgery, rats from the MLT-D1 and MLT-D2 groups received 25 and 50 mg/kg melatonin, respectively, at 7, 14, 21, 28, and 35 days. The animals were euthanised 28 days after distraction, i.e. at 43 days after surgery. Histological and histomorphometric analyses revealed that the distracted bone area was completely filled with new bone formation in all three groups. The MLT-D2 group exhibited the most new bone formation, followed by MLT-D1 and CNT. The melatonin groups had more osteoclasts than the CNT (p < 0.05). The number of osteoblasts was higher in the melatonin groups than in the CNT group, and the MLT-D2 had more osteoclasts than the MLT-D1 group (p < 0.05). Finally, the osteopontin (OPN) and vascular endothelial growth factor (VEGF) levels were higher in the melatonin groups than in the CNT group, and the MLT-D2 had higher OPN and VEGF levels than the MLT-D1 (p < 0.05). This study suggests that systemic melatonin application could increase new bone formation in DO.

Curva de Spee: causas y tratamiento de su descompensación / Spee curve: causes and treatment of its discompensation

En el presente artículo se analiza y pasa revista a la bibliográfica acerca de la Curva de Spee: su etiología, los diferentes factores que pueden descompensarla, y los posibles tratamientos para corregirla en caso deestar alterada. Una mordida abierta esqueletal o dentaria, o una mordida profunda esqueletal o dentaria pueden modificarla, pudiendo utilizarse varios recursos y técnicas para tratar estos desórdenes, y así nivelar la curva.

In the present paper, the literature is analysed and reviewed the Curve of Spee: its aetiology, the different factors that can decompensate it, and the possible treatments to correct it in case of beingaltered. An open skeletal or dental bite, or a deep skeletal ordental bite can modify it, being able to use several resources and techniques to treat these disorders, and thus to level the curve.

Mandibular range movement in pediatric patients / Rango de movimiento mandibular en pacientes pediátricos

Assessing the normal range of manibular movement becomes an indispensable tool for the clinical evaluation of the function of the masticatory system. The aim of this study was to measure the range of mandibular movement in mouth opening, protrusion, and lateral movements in pediatric subjects from the city of Temuco, Chile and to determine their association with age, sex, and height. A cross-sectional study was performed in children aged 6-13, treated in the Teaching-Unit-Dental-Clinic at the Universidad de La Frontera, Temuco-Chile. 54 subjects participated in the study (44.4 % females); girls exhibited an average mouth opening of 51.9 mm and males of 54.8 mm. Averages were 53.5 mm for mouth opening, 11.8 mm for protrusion, 9.9 mm for right laterality, and 10.3 mm for left laterality. A statistically significant difference was found between age groups, opening, and right lateral ranges, as well as a weak to moderate correlation between mouth opening and protrusion, protrusion and right laterality, protrusion and left laterality, right and left laterality, height and mouth opening, and height and right lateral ranges. The results of this study provide specific data and evidence on the importance of evaluating all ranges of mandibular movement, relating them to each other and with variables such as age and height.

La valoración de los rangos del movimiento mandibular normal y sus respectivas variaciones constituyen una herramienta indispensable para la evaluación clínica del funcionamiento del sistema masticatorio y la búsqueda de alteraciones. El objetivo de este estudio fue medir los rangos de dinámica mandibular en movimientos de apertura bucal, protrusión y lateralidades en sujetos pediátricos de la ciudad de Temuco, Chile; y determinar su asociación con edad, sexo y estatura. Se realizó un estudio de corte transversal, en niños de 6-13 años atendidos en la Clínica Odontológica Docente Asistencial de la Universidad de La Frontera, Temuco-Chile. Se evaluaron los rangos de apertura bucal, protrusión, lateralidad derecha, lateralidad izquierda, edad, sexo y estatura de los sujetos, relacionandolos entre sí. Se evaluaron 54 sujetos (44,4 % mujeres), las niñas presentaron un promedio de apertura bucal de 51,9 mm y los niños de 54,8 mm. El promedio de apertura bucal fue de 53,5 mm; el de protrusión 11,8 mm; el de lateralidad derecha 9,9 mm; y el de lateralidad izquierda 10,3 mm. Se encontró una diferencia estadísticamente significativa entre los distintos grupos de edad y el rango de apertura y lateralidad derecha, así como también una correlación débil a moderada entre el rango de apertura bucal y el de protrusión; el de protrusión y de lateralidad derecha; el de protrusión y lateralidad izquierda; el de lateralidad derecha e izquierda; estatura y apertura bucal; estatura y lateralidad derecha. Los resultados del presente estudio cobran gran importancia, ya que además de aportar con datos específicos aporta evidencia sobre la importancia de evaluar todos los rangos de movimiento mandibular, y no solo relacionarlos entre sí, sino también con variables como la edad y estatura. De este modo se facilitará el trabajo clínico de comprender la dinámica mandibular específica de cada paciente y complementarla con la sospecha de enfermedad o el diagnóstico específico de las patologías que afectan al sistema mandibular.

Estudo das variáveis cinemáticas da mastigação unilateral e habitual de indivíduos saudáveis / Study of the kinematic variables of unilateral and habitual mastication of healthy individuals

RESUMO Objetivo Descrever e comparar as variáveis cinemáticas temporoespaciais do movimento mandibular durante a mastigação unilateral deliberada e habitual de indivíduos saudáveis. Método Participaram do estudo 8 voluntários saudáveis, do gênero masculino, com faixa etária entre 19 e 24 anos. Os dados cinemáticos foram obtidos através do sistema de análise de movimento Qualysis (QTM - Qualisys Track Manager). Foram realizados registros de mastigação unilateral direita (MU) e habitual (MH) de bala de goma de gelatina de consistência firme. Foram analisadas variáveis relacionadas à (1) sequência mastigatória (duração, número de ciclos e frequência mastigatória); (2) ciclo mastigatório: duração do ciclo mastigatório, amplitude de movimento mandibular vertical e médio-lateral durante o ciclo mastigatório, velocidade máxima durante as fases de abertura e fechamento. A comparação das variáveis durante a MU e MH foi realizada por meio do teste t pareado (p<0,05) e os tamanhos de efeito (‘d’ de Cohen) foram calculados. Resultados Em relação à sequência mastigatória, observou-se menor frequência mastigatória durante MU comparada à MH (1,19±0,21 e 1,29±0,16Hz, respectivamente, p=0,004, d=0,53) e menores velocidades máximas de abertura (MU=67,4 mm/s e MH=80,02; p=0,053; d=0,80) e fechamento (MU=71,77±9,35mm/s e MH=83,51±17 mm/s, p=0,014, d=0,79) do ciclo mastigatório. Conclusão As variáveis cinemáticas relacionadas à sequência e ao ciclo mastigatório foram influenciadas pelo padrão mastigatório adotado – unilateral ou habitual.

ABSTRACT Purpose To describe and compare the temporal-spatial kinematic variables of mandibular movement during deliberate unilateral and habitual mastication in healthy young-adult individuals. Methods The study sample was composed of eight male healthy volunteers aged 19 to 24 years. The kinematic data were obtained using a motion analysis system - Qualisys Track Manager (QTM) ProReflex MCU. Recordings were performed during deliberate unilateral mastication (UM) and habitual mastication (HM) of firm-consistency gummy candy. The following variables were analyzed: (1) masticatory sequence: duration, number of masticatory cycles, and chewing rate; (2) masticatory cycle: duration, vertical and medial-lateral mandibular range of motion in relation to the skull, and maximum velocity during the opening and closing phases. Data of the variables were compared during UM and HM by the paired t test, and the effect sizes ('d' Cohen) were calculated. Results Regarding the variables of the masticatory sequence, smaller chewing rate was observed for UM compared with that for HM (1.19±0.21Hz and 1.29±0.16Hz, respectively, p=0.004, d=0.53). Smaller values of maximum velocity during the opening (MU=67.4 mm/s and MH=80.02, p=0.053, d=0.80) and closing (MU=71.77±9.35mm/s and MH=3.51±7mm/s, p=0.014, d=0.79) phases of the masticatory cycle were observed in deliberate unilateral mastication compared with those in habitual mastication. Conclusion Kinematic variables associated with the sequence and cycle of mastication are influenced by the chewing pattern adopted - deliberate unilateral or habitual.

Assessment of mandibular movements in 10 to 15 year-old patients with and without temporomandibular disorders

El objetivo del presente trabajo fue establecer valores de referencia de movimientos mandibulares en niños de 10-15 años sin disfunción; compararlos con los de pacientes de la misma edad con trastornos temporomandibulares (TTM) y con los hallados anteriormente en un grupo menor de 11 años sinTTM. Niños de ambos sexos que acudieron a la Cátedra Odontología Integral Niños de UBA en 2013 y cuyos responsables brindaron consentimiento fueron evaluados con CDI/TTM por odontopediatras estandarizados (Kappa 0.88) conformándose 3 grupos en función del resumen diagnóstico; C: sin TTM, Ia: con dolor miofacial e Ib: dolor con limitación de la apertura bucal, para el análisis de las siguientes variables: edad, sexo y movimientos mandibulares. La muestra quedó constituida por169 pacientes de 12.5±1.76 años. El 62.36 por ciento no presentó TTM (C) y en el 37.27 por ciento se estableció un diagnóstico de trastorno muscular (29.58 por ciento Ia y 7.69 por ciento Ib). En C se registraron lossiguientes valores en mm: Apertura máxima no asistida: 48.28±6.14; Lateralidad derecha 8.78±2.50; izquierda: 9.60±2.64; Protrusión: 4.94±2.58 y Sobremordida: 2.98 ± 2.5sin variaciones en relación al sexo, pero con diferencias en los registros de todos los movimientos comparados con losobtenidos en dentición mixta. (p=0.0001). El análisis de los valores medios de los movimientos mandibulares entre los 3 grupos sólo reveló diferencias para la apertura máxima no asistida (p= 0.0317). En relación al sexo, los TTM fueron másfrecuentes en niñas siendo significativa la diferencia entre C e Ia (p=0.019). En los niños sin disfunción se estableció unaapertura máxima promedio de 48.28±6.14mm, observándose valores inferiores en los pacientes con TTM. Los movimientos mandibulares en pacientes pediátricos sin TTM mostrarondiferencias significativas en función del tipo de dentición y la edad...

mean visible labial length of maxillary and mandibular anterior teeth at rest

To determine the mean visible labial length of maxillary and mandibular anterior teeth at rest. Cross-sectional study. Department of Prosthodontics, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Karachi, from October 2012 to March 2013. A total of 200 subjects were included. Measurements were carried out using digital caliper from the border of the lip to the incisal edges of incisor and to the cusp tip for the canines. The length of the upper lip was measured from subnasale to stomion. Statistical analyses were performed by Mann Whitney-U test and Kruskal Walli's test. The age of the participant ranged between 20 and 65 years. At rest, females significantly displayed more of the maxillary central incisor [2.93 +/- 1.57 mm; p=0.003], lateral incisor [1.87 +/- 1.12 mm; p=0.005] and canine [0.59 +/- 0.62 mm; p=0.031]. With increasing age, the amount of maxillary anterior teeth visible at rest significantly decreased [p < 0.001], and increased for the mandibular teeth [p < 0.001]. Subjects with shorter upper lips significantly displayed more maxillary anterior incisor structure than subjects with longer upper lip [p < 0.001]. Females displayed significantly more labial length of the maxillary anterior teeth. The mean visible labial length of maxillary anterior teeth significantly decreased with increasing age and increased for the mandibular teeth. As the upper lip length increased, the mean visible labial length of maxillary anterior teeth significantly decreased

Estudo da correlação entre a posição do disco da articulação temporomandibular, avaliada através da técnica do relógio em exames de ressonâncias magnéticas com a posição da cabeça da mandíbula avaliada pelo método de Pullinger / Correlation between the position of the temporomandibular joint disk, measured by the clock technique in MRIs, with the position of the condyle carried at Pullinger method

A associação entre sinais e sintomas de Disfunções Temporomandibulares (DTM) e achados em imagens de ressonância magnética (RM) tem sido controversa, dessa forma, este estudo avaliou a posição do disco, pelo método do relógio, e verificou a associação com a posição da cabeça da mandíbula, com a dor muscular à palpação, abertura passiva e ativa, presença de estalo e idade em pacientes portadores de DTM que foram submetidos ao exame de RM. O disco foi classificado em 0- posição normal (banda posterior em 11 e 12 horas); 1- início do deslocamento (posição entre 11 e 10 horas); 2- deslocamento médio (posição entre 10 e 9 horas); e 3- deslocamento avançado (posição entre 9 e 8 horas). A posição da cabeça da mandíbula foi classificada de acordo com o método de Pullinger em 1- posterior; 2- anterior; e 3- concêntrica. As classificações foram realizadas por três examinadores. A associação entre os dados clínicos e imaginológicos foi realizada utilizando o coeficiente de correlação intraclasse, coeficiente de correlação de Spearman, análise de variância, teste exato de Fisher ou teste de Kruskal-Wallis conforme a necessidade, com 5% de nível de significância. Sessenta casos foram incluídos no estudo, com predomínio de mulheres e média de 37 anos de idade. Houve concordância excelente entre os examinadores para posição do disco e da cabeça da mandíbula, porém não houve correlação entre essas duas variáveis. A presença de estalo, dor muscular à palpação e amplitude de abertura de boca também não apresentaram correlação estatisticamente significante com a posição do disco. Apenas a dor muscular à palpação foi associada a abertura de boca (p<0,05). Conclui-se que não há associação entre sinais e sintomas clínicos e posição do disco com a posição da cabeça de mandíbula em pacientes portadores de DTM...

The association between signs and symptoms of temporomandibular disorders (TMD) and findings on magnetic resonance imaging (MRI) has been controversial, thus, this study evaluated the disc position, by the clock method, and verified the association with the condyle position, muscle pain on palpation, passive and active opening, presence of temporomandibular joint (TMJ) sound and age in patients with TMD who underwent MRI. The disc position was classified as 0 - normal position (posterior band at 11 and 12 hours); 1 - mild displacement (position between 11 and 10 hours); 2 - Moderate displacement (position between 10:09 hours); and 3 - Severe displacement (position 9 to 8 hours). The condyle position was graded according to the Pullinger's method as 1 - posterior; 2 - anterior; and 3 - concentric. Three examiners performed the analyses. The association between clinical and imaging data was performed using the intraclass correlation coefficient ICC -, Spearman correlation coefficient, analysis of variance, Fisher's exact test or Kruskal-Wallis test as appropriate, with 5% significance level. Sixty cases were included in the study, with a predominance of women and average age of 37. There was excellent agreement between the examiners to disc and condyle position, but there was no significant correlation between these two variables. The presence of TMJ sound, muscle pain on palpation and range of mouth opening also showed no statistically significant correlation with the disc position. Only muscle pain on palpation was associated with mouth opening (p <0.05). It is concluded that there is no association between clinical signs and symptoms and disc position with condyle position in patients with TMD...

The effect of a Lucia jig for 30 minutes on neuromuscular re-programming, in normal subjects

The Lucia jig is a technique that promotes neuromuscular reprogramming of the masticatory system and allows the stabilization of the mandible without the interference of dental contacts, maintaining the mandible position in harmonic condition with the musculature in normal subjects or in patients with temporomandibular dysfunction (TMD). This study aimed to electromyographically analyze the activity (RMS) of the masseter and temporal muscles in normal subjects (control group) during the use of an anterior programming device, the Lucia jig, in place for 0, 5, 10, 20 and 30 minutes to demonstrate its effect on the stomatognathic system. Forty-two healthy dentate individuals (aged 21 to 40 years) with normal occlusion and without parafunctional habits or temporomandibular dysfunction (RDC/TMD) were evaluated on the basis of the electromyographic activity of the masseter and temporal muscles before placement of a neuromuscular re-programming device, the Lucia jig, on the upper central incisors. There were no statistically significant differences (p < 0.05) in the electromyographic activity of the masticatory muscles in the different time periods. The Lucia jig changed the electromyographic activity by promoting a neuromuscular reprogramming. In most of the time periods, it decreased the activation of the masticatory muscles, showing that this device has wide applicability in dentistry. The use of a Lucia jig over 0, 5, 10, 15, 20 and 30 minutes did not promote any statistically significant increase in muscle activity despite differences in the data, thus showing that this intra-oral device can be used in dentistry.

Emerging applications of an experimental single photon emission computed tomography: an analysis of 16 areas of interest in the pig's model / Aplicaciones emergentes experimentales de la tomografía computarizada por emisión de fotones individuales: un análisis de 16 áreas de interés en el modelo de cerdo

This paper aims to affirm various new applications of single photon emission computed tomography (SPECT) technique by utilizing the pig's models. Evaluation and subsequent analysis of SPECT results was conducted on the jaws of eight experimental pigs with a total of 16 areas of interest. The various reasons for which each experiment was conducted were evaluated and these reasons include: i) validation of a new bone grafting technique for closure of oro-antral communications, ii) comparison of autogeneous bone graft with other bone grafts, iii) sequential confirmation of osteoblastic activity of the sandwich bone regeneration technique with another technique, iv) validation of the use of a new membrane for guided tissue regeneration (GTR), v) validation of the fact that osseointegration is better with beaded implants than with threaded implants, and vi) validation of the fact that GTR is essential for immediate implant practice. The outcome of this evaluation is critically analysed against the background of the substantial clinical evidence where applicable, so as to appreciate the position of SPECT. Following the evaluation of 16 areas of interest in eight experimental pigs, it was shown that experimental SPECT was valuable in the validation of the above reasons. It appears to be a modality that can continuously be utilized to validate and compare situations which would display osteoblastic activities. It is concluded that the bone scintigraphy imaging technique accurately reflects osteoblastic activities and can now be used to validate osseointegration of any implant or bone-grafting system. This can be done in conjunction with histological and histomorphometic analysis and such results obtained from SPECT should be correlated with the histological and histomorphometric analysis if available.

El presente trabajo tiene por objeto dar a conocer varias nuevas aplicaciones de la técnica de la tomografía computarizada por emisión de fotones individuales (inglés SPECT), utilizando modelos de cerdo. Se llevó a cabo una evaluación y el posterior análisis de los resultados de la SPECT en relación con las mandíbulas de ocho cerdos experimentales con un total de 16 áreas de interés. Se evaluaron las varias razones por las que se llevó a cabo cada experimento. Las razones incluyen: i) validación de una nueva técnica de injerto óseo para el cierre de las comunicaciones oroantrales; ii) comparación del injerto óseo autógeno con otros injertos óseos; iii) confirmación secuencial de la actividad osteoblástica de la técnica de regeneración ósea por "sándwich" o membrana inter-posicional con otra técnica; iv) validación del uso de una nueva membrana para la regeneración tisular guiada (RTG); v) validación del hecho que la osteointegración es mejor con implantes porosos que con implantes roscados; y vi) valoración del hecho de que la RTG es esencial para la práctica del implante inmediato. El resultado de esta evaluación se analiza críticamente contra el trasfondo de la evidencia clínica sustancial donde es aplicable, para apreciar la posición de SPECT. Tras la evaluación de 16 áreas de interés en ocho cerdos experimentales, se vio que la SPECT experimental era valiosa para la validación de las razones anteriores. Parece ser una modalidad que puede utilizarse para validar y comparar situaciones que desplegarían actividades osteoblásticas. Se concluye que la gammagrafía ósea refleja las actividades osteoblásticas con precisión, y puede ahora usarse para validar la osteointegración de cualquier implante o sistema de injerto óseo. Esto puede hacerse junto con análisis histológicos y análisis histomorfométicos. Los resultados obtenidos de la tomografía SPECT deben ponerse en correlación con el análisis histológico e histomorfométrico, si estuviese disponible.

Mathematical model for osteobstruction in bone regeneration mechanisms a Headway in skeletal tissue engineering / Modelo matemático de la osteobstrucción en el mecanismo de regeneración del hueso: un avance en la ingeniería del tejido esquelético

In this paper, we formulate a mathematical model for the evaluation of parameters responsible for the retardation and eventual acceleration of bone regeneration on the contralateral side of the mandible of experimental animals, following the discovery of a new mechanism of bone regeneration called the osteobstruction mechanism (a negative mechanism of bone regeneration as opposed to the well established and extensively documented positive mechanisms such as osteogenesis, osteoinduction and osteoconduction). This osteobstructive mechanism was demonstrated by episodes of overtaking and re-overtaking on single photon emission computed tomography (SPECT) following evaluation of osteoblastic activities in a sequential animal experiment to validate both the Ogunsalu sandwich technique (a double guided tissue technique; D-GTR) and the interceed membrane technique (a single guided tissue regeneration technique; S-GTR) utilizing SPECT, histological and histomorphometric evaluation. This work is now given special attention in terms of mathematical analysis because of limited experimental observations since experiments cannot be observed infinitely. Mathematical modelling is as such essential to generalize the results of this osteobstructive mechanism in bone regeneration. We utilize the Fisher's equation to describe bone cell mobilization during bone regeneration by two different techniques: the Ogunsalu sandwich bone regeneration technique (D-GTR) and the S-GTR.

En este trabajo se formula un modelo matemático para la evaluación de los parámetros responsables del retardo y la posterior aceleración de la regeneración del hueso en el lado contralateral de la mandíbula de animales experimentales, tras el descubrimiento de un nuevo mecanismo de regeneración del hueso, denominado mecanismo de osteobstrucción de la regeneración del hueso (un mecanismo negativo de regeneración del hueso, el cual contrasta con mecanismos positivos bien establecidos y ampliamente documentados, tales como la osteogénesis, la osteoinducción y la osteoconducción). Este mecanismo osteobstructivo fue demostrado mediante una serie de fenómenos consecutivos en la tomografía computarizada por Emisión de Fotones Individuales (SPECT), tras la evaluación actividades osteoblásticas en experimentos secuenciales con animales, para validar tanto la técnica de sandwich de Ogunsalu (técnica de regeneración de tejidos guiada doble; RTG-D) como la técnica de membrana con interceed (técnica de regeneración de tejidos guiada simple; RTG-S) utilizando SPECT así como evaluaciones histológicas e histomorfométricas. Este trabajo recibe aquí especial atención en términos de análisis matemático, ya que en los experimentos las observaciones no puede realizarse infinitamente. Los modelos matemáticos son pues esenciales para generalizar los resultados de este mecanismo del osteobstructivo de la regeneración ósea. Se utiliza la ecuación de Fisher para describir la movilización de las células óseas durante la regeneración del hueso por dos técnicas diferentes: la técnica de Ogunsalu para la regeneración ósea por "sandwich" (D-GTR) y la técnica S-GTR.

Histomorphometric analysis of the temporal bone after change of direction of force vector of mandible: an experimental study in rabbits

OBJECTIVES: The present study aimed at performing a histological evaluation of the response of temporal bone tissue to a change of direction of the force vector of the mandible in relation to the base of the skull. MATERIAL AND METHODS: Adult rabbits were assigned into four groups with two control and four experimental animals in each group. experimental animals underwent surgery, which resulted in a change of direction of the force vector on the right temporomandibular joint. Samples were collected after 15, 30, 60 and 90 days for histological analysis. RESULTS: In the two-way analysis of variance, the effect of group and time was statistically significant (p<0.001). Additionally, a statistically significant interaction between group and time was observed (p<0.001). Control animals showed normal growth and development of the temporal region. In the experimental group, the change in direction of the force vector of the mandible induced significant changes in the temporal bone, with a bone modeling process, which suggests growth of this cranial structure. CONCLUSIONS: The methodology used in this experiment allows us to conclude that the change in direction of the force vector of the mandible in relation to the skull base induces remodeling and modeling processes in the temporal bone. The resumption of normal oral functions after bone healing of the mandibular fracture appears to increase cell activation in the remodeling and modeling of the temporal bone structure. The observation of areas of temporal bone modeling shows the relevance of further investigation on the correlation between the joint structures and craniofacial growth and development.

Control vertical en pacientes en crecimiento / Vertical control in growing patients

Todo tratamiento de ortodoncia debe tener como sustento una filosofía de diagnóstico. En la actualidad, resulta fácil lograr resultados estéticos en cuanto a alinear dientes, cerrar espacios, pero es tremendamente importante no perder de vista los objetivos de tratamiento, que permiten alcanzar una ortodoncia seria, crítica, analítica, basada en la filosofía que nuestros maestros nos mostraron y a la cual adherimos. Para el Dr. Roth, la clave era conseguir una oclusión funcional, en la que los pacientes se encuentren en armonía con la articulación temporomandibular y es de suma importancia conocer con qué herramientas terapéuticas contamos para alcanzarla. El control vertical es sin duda una de ellas y cobra protagonismo en aquellos que, por su edad, nos permiten modificar ciertos aspectos de su crecimiento, mejorando las condiciones para alcanzar con éxito la respuesta mandibular deseada.