Artículos de Investigación

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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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Assessment of Maxillary Premolar Region in Relation to Maxillary Sinus Floor and Buccal Bone Plate: A Cone Beam Computed Tomography Study
(2019)
Ramón Fuentes
;
Manuel Arellano Villalón
;
Soto-Faúndez, Natalia
;
Alain Arias
;
Montiel, Ignacio
The maxillary sinus floor location and the buccal bone plate are factors to be considered in the long-term success with implant treatments mainly in the premolar region. the aim of this study was to establish morphometric characteristics of the buccal cortical bone (BCB) thickness of maxillary premolars and its relation to maxillary sinus floor through CBCT. In this study 350 first and second maxillary premolars were analyzed from 110 CBCT images and the buccal cortical bone (BCB) was measured in a coronal view at the major axis level of each premolar. In addition, in 200 first and second maxillary premolars CBCT images were measured the distance from premolar apex to maxillary sinus floor (MSF) in both frontal and sagittal plane. The type of relationship between the apex and MSF was classified according to Ok et al. (2014). The second premolar was observed with higher values of BCB (p<0.001). In first premolar, higher values were observed in the male sex (p>0.05). In second premolar, only significantly higher values were observed in the male sex in MA-MB-MC (p>0.05). Regarding to MSF and its relation to premolar roots, it was observed that 10 % of the sample was classified as type I, 19 % as type II, 55.5 % as type III and 15.5 % as type IV. The BCB of the upper premolar region is thicker in the apical region and decreases toward the coronal region. Almost 50 % of apex of second premolars are closely and risky related MSF (Type I and II).
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Patrones de Deglución y Metodología de Evaluación. Una Revisión de la Literatura
(2019)
Priscila Chuhuaicura
;
Giannina Álvarez
;
Lezcano, María Florencia
;
Alain Arias-betancur
;
Fernando Jose Dias
La deglución es una función indispensable para el ser humano, es una actividad compleja que necesita de la participación y coordinación de múltiples estructuras. Actualmente existen diferentes métodos para evaluar este proceso, sin embargo, la capacidad de describir el comportamiento de las estructuras en sus tres dimensiones es limitada. Se ha demostrado que el movimien to lingual, es clave para la formación del bolo alimenticio y la propulsión de este a la orofaringe. Es así como se han identificado patrones de movimiento lingual a través de diferentes técnicas. El objetivo de esta revisión es reportar las diferentes técnicas de evaluación de la deglución e identificar los patrones que establece cada una de ellas. Se realizó una revisión de la literatura en distintas bases de datos, a través de una estrategia de búsqueda sistematizada. Se utilizaron las palabras clave “Deglutition” “Swallowing” “Movement Tracking” “evaluation” y “patterns” en inglés y español. Se incluyeron estudios sin límite en la fecha de publicación, realizados en humanos, en idioma inglés, español y portugués. Se encontraron diferentes técnicas para evaluar la deglución, videofluoroscopía, endoscopía, articulografía electromagnética, electromiografía, tomografía computarizada, manometría, electropalatografía y ultrasonido. Entre las cuales la videofluoroscopía es una de las más utilizadas, con esta técnica se ha intentado describir patrones del movimiento durante la deglución, al igual que la articulografía electromagnética. Por otro lado, la electromiografía ha descrito patrones de deglución, pero en relación a la contracción y relajación de ciertos grupos musculares. Existen diferentes métodos para evaluar la deglución, cada una de estas técnicas ha permitido dilucidar de mejor forma este proceso, no obstante, es necesario una mayor cantidad de estudios comparativos que permitan resolver las dudas sobre la validez y la eficacia de las técnicas descrit
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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.
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Presencia y Relaciones Anatomofuncionales del Ligamento Discomaleolar. Una Revisión de la Literatura
(2018)
Carlos Salamanca
;
Fernando J Dias
;
Ramón Fuentes
El Ligamento Discomaleolar es una estructura que no se describe en los textos clásicos de anatomía a pesar de ser descrito por primera vez por Rees, Pinto y luego por diversos autores como una estructura ligamentosa de tejido fibroelástico que conecta el cuello y el proceso anterior del martillo a través de la fisura petrotimpánica hasta la parte medioposterosuperior de la cápsula de la articulación temporomandibular (ATM), el disco articular y el ligamento esfenomandibular. Diversos estudios han reportado las implicaciones clínicas del ligamento discomaleolar y la relación entre los trastornos temporomandibulares con los síntomas asociados al oído medio. El objetivo de este estudio fue realizar una revisión sobre estudios que describen el ligamento discomaleolar y determinar si se considera una estructura independiente anatómica y funcionalmente y su relación con el oído medio. Se realizó una búsqueda de literatura científica identificó artículos donde se identifican las estructuras anatómicas asociadas a la articulación témporomandibular y el oído medio, fueron seleccionados 24 artículos según los criterios de selección. Los resultados obtenidos en los estudios seleccionados en esta revisión sugieren la existencia de una lámina o fascículo fibroso que conecta el disco de la ATM con el maléolo del oído medio, lo que validaría la presencia y relación entre el ligamento discomaleolar y los trastornos del oído medio.
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A Novel Three-Dimensional Analysis of Tongue Movement During Water and Saliva Deglutition: A Preliminary Study on Swallowing Patterns
(2018)
Giannina Álvarez
;
Fernando José Dias
;
María Florencia Lezcano
;
Alain Arias-betancur
;
Ramón Fuentes
Deglutition is a complex oral function, and the study of the whole process requires a precise analysis of the elements involved, especially of the tongue biomechanics. We described a three-dimensional analysis of tongue movements during both saliva and water deglutition in participants with normal occlusion. Fourteen participants (25.36 ± 4.85 years) were evaluated, and the movements of anterior, middle, and posterior portions of the tongue were recorded using AG501 3Delectromagnetic articulograph. An average volume (AVS) for water deglutition was determined for each participant. Saliva deglutition was classified according to Bourdiol et al. 35.71% was type I, 14.29% type II, and 50% type III. The greatest displacement on the inferior–superior axis was in the posterior portion, followed by the middle and anterior portions. In the posterior–anterior axis, smallest movement was in the anterior portion. During water deglutition, on the inferior–superior axis, there were statistical differences for 1-AVS between the anterior/middle and anterior/posterior portions of the tongue. There were statistical differences for both -AVS and -AVS between the anterior/posterior portions of the tongue. On the posterior–anterior axis, there were no statistical differences among any volume–portion relations. On the medial–lateral axis, there was statistical difference for the -AVS between middle and posterior portions. The movement of the tongue portions was influenced by the volume and the element to be swallowed. The amplitude of the movement was directly proportional to the volume of water swallowed.

Artículos de Investigación

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