Artículos de Investigación

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    Description of intraoral pressures on sub-palatal space in young adult patients with normal occlusion
    (2015)
    Fuentes, Ramón
    ;
    Engelke, Wilfried
    ;
    Flores, Tania
    ;
    Navarro, Pablo
    ;
    Borie, Eduardo
    Under normal conditions, the oral cavity presents a perfect system of equilibrium between teeth, soft tissues and tongue. The equilibrium of soft tissues forms a closed capsular matrix, generating differences with the atmospheric environment. This difference is known as intraoral pressure. Negative intraoral pressure is fundamental to the stabilization of the soft palate and tongue, reducing neuromuscular activity for the permeability of the respiratory tract. Thus, the aim of this study was to describe the variations of intraoral pressure of the sub-palatal space (SPS) under different physiological conditions and biofunctional phases. A case series was conducted with 20 individuals aged between 18 and 25. The intraoral pressures were measured through a system of cannulae connected to a digital pressure meter in the SPS during seven biofunctional phases. Descriptive statistics were used based on the mean and standard deviation. The data recorded pressure variations under physiological conditions, reaching 65 mbar as the intraoral peak in forced inspiration. In the swallowing phase, peaks reached -91.9 mbar. No pressure variations were recorded in terms of atmospheric changes with the mouth open and semi-open. The data obtained during the swallowing and forced inspiration phases indicated forced lingual activity. In the swallowing phase, the adequate position of the tongue creates negative intraoral pressure, which represents a fundamental mechanism for the physical stabilization of the soft palate. This information could contribute to subsequent research into the treatment of primary roncopathies.
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    Evaluación de la Fuerza Masticatoria Máxima Funcional en Adultos Jóvenes Chilenos
    (2015)
    Curiqueo, Aldo
    ;
    Pinto-Salamanca, Carlos-Eduardo
    ;
    Borie, Eduardo
    ;
    Navarro, Pablo
    ;
    Fuentes, Ramón
    La fuerza masticatoria m xima funcional (FMMF) se ha definido como la m xima fuerza generada entre los dientes maxilares y mandibulares. As el objetivo de esta investigaci n fue de obtener datos reales sobre las FMMF a nivel molar, premolar, canino e incisivo en individuos adultos j venes. El estudio incluy una muestra de 50 individuos entre 18 y 25 a os de edad, totalmente dentados y con perfil esqueletal tipo I y clase I molar y canino. Se utiliz como instrumento un dispositivo de medici n de fuerzas port til, realizando las medidas en la regi n molar, premolar, canina e incisiva. A los individuos se les indic morder el instrumento con la mayor fuerza posible, alternando las diferentes zonas a medir, aplic ndose tres mediciones en cada diente y registrando el mayor valor en cada zona. La media de las fuerzas ejercidas del sexo masculino fue de 698, 516, 322 y 220 N, en las regiones molar, premolar, canina e incisiva, respectivamente. Por otro lado, en el sexo femenino se observaron valores medios de 466, 431, 232 y 174 N en las regiones molar, premolar, canina e incisiva, respectivamente. Se puede concluir que se observaron diferencias significativas de FMMF entre ambos sexos en las diferentes regiones, identificando los mayores valores en los individuos de sexo masculino en la regi n molar. Adem s, se identificaron diferencias significativas de la FMMF s lo en la regi n canina del sexo masculino al relacionarlas con el lado del arco.
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    Análisis Cinemático de la Masticación de una Granola Prototipo en Contraste con la Masticación de Maní
    (2020)
    Constanza Farfán
    ;
    Joel Jerson Coaquira-Quispe
    ;
    María Florencia Lezcano
    ;
    Alain Arias
    ;
    Pablo Navarro
    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.
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    Characteristics of Mandibular Movement and Mastication in Older Adults with Removable Dental Prostheses: Three-Dimensional Analysis
    (2020)
    Paloma Rivera
    ;
    Constanza Farfán
    ;
    Alain Arias
    ;
    María Florencia Lezcano
    ;
    Fernando José Dias
    Aging is a dynamic process that includes various alterations in the oral cavity, with tooth loss being the most frequent. Rehabilitative treatment may include removable or fixed prostheses and implants. The aim of this study was to describe the geometric (trajectory, ranges, areas) and kinematic (speed) characteristics of the mandibular and masticatory movements threedimensionally in participants with dental prostheses. A sample of 10 participants with removable prosthetic rehabilitation was divided into three groups (complete, atypical and overdenture) the characteristics of mandibular movements bordering and chewing with 3D Electromagnetic Articulography were measured. The Posselt polygonin was obtained, the frontal and sagittal plans, its areas, trajectories and ranges are analyzed. The masticatory movements were analyzed in the area of each cycle, the frequency, the speed and the reason between the masticatory cycle and the bordering movements, no significant differences between the groups. Subjects with dental prostheses, regardless of the type, they showed low of motion (border and functional) compared to dentate subjects with no functional alterations whose values have been reported in the literature. The subjects with overdenture have values closer to what is described for young dentate subjects.
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    Location and course of the mandibular canal in dentate patients: morphometric study using cone-beam computed tomography
    (2019)
    Alain Arias
    ;
    C. Venegas
    ;
    N. Soto
    ;
    I. Montiel
    ;
    C. Farfán
    Background: The morphometric characteristics of the mandibular canal (MC) may vary according to the characteristics of the population studied. Correct location of the MC is fundamental for the indication and planning of different dental treatments, and it is therefore essential to have clinical parameters indicating its approximate location. The aim of this study was to describe the location and course of the MC by morphometric relations in the mandibular body, from the mental foramen to distal of the first molar, in dentate adult patients. Materials and methods: We analysed 55 cone-beam computed tomography (CBCT) of male and female patients, aged over 18 years and with fully dentate to the first molar. In each CBCT we selected five coronal sections (A-E) of the mandibular body at different levels using the teeth as references. We determined different morphometric measurements in each section to relate the MC with the corticals of the mandibular body (m1, m2, m3, m4), their orientation to lingual (F) and the thickness of the mandibular corticals (B1, B2 and B3). Results: The distance between the MC and the alveolar crests was greater in males than in females in all the sections. In general, in all the hemiarches, the MC courses away from the vestibular cortical of the mandible (and in some cases significantly towards the lingual cortical) from anterior to posterior in the mandibular body. In the left hemiarch of dentate females the MC describes a descent in the molar zone within the mandibular body. Any intervention in the mandible must be carried out with extreme caution to avoid damaging the vasculo-nervous bundle which passes through the MC. Conclusions: Cone-beam computed tomography is the best tool currently available for the planning and execution of surgical procedures, and is the only tool in clinical use which allows the precise course of the MC to be identified.
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    Relación entre Síntomas de Trastornos Témporomandibulares Auto-Reportados y el Movimiento Mandibular de Sujetos Adultos Jóvenes
    (2019)
    Alain Arias
    ;
    Diego Saravia
    ;
    Melanie Quintana
    ;
    Fernando Dias
    ;
    María Florencia Lezcano
    Tanto la limitación del movimiento mandibular como el auto reporte de síntomas de trastornos témporomandibulares (TTM) son utilizados como elementos para el diagnóstico de pacientes en la clínica. Sin embargo, la relación entre la presencia de síntomas y el movimiento mandibular no está del todo clara. Por ello, el objetivo de este estudio fue relacionar la presencia de síntomas asociados a TTM con el movimiento mandibular en una muestra de sujetos adultos jóvenes y sanos. En este estudio exploratorio participaron 40 estudiantes de Odontología, médicamente sanos, con arco dentario maxilar y mandibular continuo y completo (hasta el primer molar). A cada uno se les solicitó responder un cuestionario de auto-reporte de síntomas asociados a TTM recomendado por la American Academy of Orofacial Pain (AAOP). También se realizó un registro y análisis de sus movimientos mandibulares utilizando articulografía electromagnética 3D, con el objetivo de correlacionar la presencia de síntomas con el rango y trayectoria de apertura, y el área comprendida en lo que se describe como polígono de Posselt en el plano frontal y sagital. No se encontraron diferencias significativas entre las respuestas a cada pregunta entre hombres y mujeres. De acuerdo a las respuestas y según Delcanho (1994), 12 participantes resultaron necesitar una evaluación más exhaustiva. En este grupo se encontró que el área del polígono de Posselt en el plano frontal, fue significativamente menor que el de aquellos participantes que no requieren una evaluación más exhaustiva (p=0,003). Los valores de la trayectoria de apertura mandibular varían según de que síntoma se trate. Los principales síntomas que afectarían los valores de los movimientos bordeantes son la “dificultad para abrir la boca” y el “ruido en las articulaciones mandibulares”. Con este estudio, hemos puesto de manifiesto que la limitación del movimiento mandibular como signo de TTM debe evaluarse con cautela, debido a que según la presencia de determinados síntomas y otras características de los sujetos (como el sexo), su valor podría variar.
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    Platelet‐rich fibrin and collagen membrane in the preservation of the alveolar bone: Feasibility of the elemental inorganic composition and scanning electron microscopy analysis
    (2019)
    Fernando José Dias
    ;
    Alain Arias
    ;
    Eduardo Borie
    ;
    Ramón Fuentes
    <jats:title>Abstract</jats:title><jats:p>The success of dental implants is related to the amount, quality, and composition of the alveolar bone. The placement of platelet‐rich fibrin (PRF) clot associated with a resorbable collagen membrane (RCM) in a postextraction alveolus is a technique used for ridge preservation. This case report study analyzed the ultrastructural characteristics of cross‐sectioned alveolar bone that received PRF and RCM using scanning electron microscopy and the inorganic composition using “energy dispersive X‐ray spectrometry,” in order to explore the feasibility of this method to clinical studies. Three alveolar bone samples from two male patients (37 and 58 years old), obtained in the procedure of placing the dental implant, were analyzed. Two bone samples previously received PRF and RCM (M37 and M58), the third sample represented a physiological bone formation without treatment (M37‐control). The bone sample M37 showed irregularly shaped islets of calcified material intermingled with connective tissue. The other samples, from the 58‐year‐old patient with PRF and RCM (M58); and the other untreated bone sample from the same 37‐year‐old patient (M37‐control) showed similar ultrastructural morphology with trabecular conformation without islets agglomerations. The inorganic composition analysis showed higher concentrations of calcium and phosphorus in both samples treated with PRF and RCM in comparison to the untreated bone sample. The Ca/P ratio was higher in the M37 sample compared to the others samples. The results showed morphology and inorganic composition differences among the treatments used, suggesting that this method is feasible to analyze parameters of the alveolar bone tissue.</jats:p>
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    Comparison of Morphological Quantitative Characteristics of the Newly Formed Alveolar Bone After the Application of Demineralized Bone Matrix and Cortical Bone Allografts
    (2019)
    Fernando José Dias
    ;
    Alain Arias
    ;
    Eduardo Borie
    ;
    Maria Florencia Lezcano
    ;
    Manuel Arellano-Villalón
    The allografts were used to obtain sufficient alveolar bone tissue for proper dental implant placement. The objective of the present study was to evaluate the morphological and quantitative characteristics (cellular and collagen densities) of the newly formed alveolar bone with the application of cortical bone (CB) and demineralized bone matrix (DBM) allografts. Six samples of alveolar bone tissue from 5 patients (50 ± 6.3 years) were obtained after 6 months of application of the allografts and immediately before the placement of the dental implants. The samples were fixed (buffered formaldehyde, pH7.2), decalcified (EDTA 10 %) and histologically processed (HE and Picro-Sirius) for histologic analysis. Morphological analysis revealed presence of osteocytes and trabeculae in neoformed bone tissue near the allografts and absence of inflammatory and allergic cells; the remnants of CB were located mainly in the periphery of the bone tissue and the remnants of DBM were more incorporated into the tissue. Osteogenitor cells were observed around the remaining material. The cell density was not modified in newly formed bone tissue with the application of both allografts as compared to mature bone tissue. The density of the type I and III collagens present in the osteoids interspersed with the remainder of the materials showed a tendency to increase in the samples treated with DBM. It was concluded that by the histological characteristics observed both grafts were biocompatible, however the bone treated with DBM presented better incorporation and a tendency of increase of the collagen content in the remnant region of the allografts.
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    Mastication as a protective factor of the cognitive decline in adults: A qualitative systematic review
    (2019)
    Priscila Chuhuaicura
    ;
    Fernando José Dias
    ;
    Alain Arias
    ;
    María Florencia Lezcano
    ;
    Ramón Fuentes
    Introduction: A relationship between masticatory function and cognition has been reported. It is proposed that mastication changes the blood flow stimulating the perfusion/oxygenation of the brain. This literature review analysed the relation between mastication as a protective factor of the cognitive decline and the changes produced at brain level in adults associated with the brain blood flow. Materials and methods: A systematic review was performed according to the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' (PRISMA) criteria in PubMed/MEDLINE, Web of Science, Scopus and Embase. Primary studies were included with no limit on the publication date, conducted on humans, and that established a relation between mastication, brain blood flow and cognitive functions in adult patients. Results: Nine clinical descriptive studies were selected and qualitatively analysed. The collected data suggest the greatest brain areas activated during mastication were the frontotemporal cortex, the caudate nucleus and the thalamus, revealing a positive correlation between chewing intensity and perfusion of the principal trigeminal nucleus. The increase in cerebral blood flow was measured by a local vasodilator effect resulting in increased neuronal metabolism in the region linked to learning and memory. In addition, partially edentulous participants had a marked prefrontal deactivation when they chewed without a prosthesis and presented a decrease in masticatory activity. Conclusion: Masticatory function may act as a protective factor in those patients with cognition impairment and neurodegenerative diseases, suggesting some mechanisms among which is the increase of cerebral blood flow.
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    Estudiantes de la Salud como Sujetos de Estudio en Investigación: Una Revisión Acerca de su Incorporación e Implicancias Éticas
    (2019)
    Nicolás Astete
    ;
    Alain Arias
    ;
    Ramón Fuentes
    El propósito de este estudio fue conocer las implicancias involucradas sobre uso de estudiantes de la salud como sujetos de estudio en investigación. Se realizó una revisión de la literatura en las bases PUBMED, EMBASE, SCOPUS, EBSCOhost y SciELO, sin límites de años y con criterios de elegibilidad. Se encontraron un total 215 artículos, se realizó una selección de estos y se eliminaron estudios que se referían a otras poblaciones vulnerables o que evaluaban características psicológicas de los estudiantes sin una relación hacia la participación como sujetos de estudio. A excepción de un estudio cualitativo de entrevista, todos son estudios descriptivos de revisión narrativa, carta al editor o aplicación de encuestas, que expresan ciertas consideraciones que deben ser abordadas al utilizar estudiantes como sujetos de estudio. Es necesario realizar estudios en otras poblaciones de estudiantes y con una mayor rigurosidad en su metodología, y así poder evaluar el real beneficio educativo de su participación y sus percepciones sobre esta instancia. La sociedad científica hace un llamado a generar una guía que unifique los criterios que se deben considerar al seleccionar estudiantes como sujetos de estudio y así permitir que los investigadores, las instituciones de revisión ética y los editores de revistas científicas poder evaluar de mejor manera los estudios en estas poblaciones.