Addition of Saccharomyces eubayanus to SCOBY fermentations modulates the chemical and volatile compound profiles in kombucha.

Kombucha is a fermented beverage derived from a sweetened tea fermentation inoculated with a bacteria-yeast consortium referred to as Symbiotic Culture of Bacteria and Yeast (SCOBY). Different SCOBY cultures can impact the beverage's quality and make the whole process highly variable. Adding Saccharomyces yeast cultures to the fermentation process can avoid stalled fermentations, providing a reproducible beverage. Here, we explored using different Saccharomyces eubayanus strains together with SCOBY in the context of kombucha fermentation. Our results show that yeast x SCOBY co-cultures exhibited a robust fermentation profile, providing ethanol and acetic acid levels ranging from 0,18-1,81 %v/v and 0,35-1,15 g/L, respectively. The kombucha volatile compound profile of co-cultures was unique, where compounds such as Isopentyl acetate where only found in yeast x SCOBY fermentations. Metabarcoding revealed that the SCOBY composition was also dependent on the S. eubayanus genotype, where besides Saccharomyces, amplicon sequence variants belonging to Brettanomyces and Starmerella were detected. These differences concomitated global changes in transcript levels in S. eubayanus related to the metabolism of organic molecules used in kombucha fermentation. This study highlights the potential for exploring different S. eubayanus strains for kombucha fermentation, and the significant yeast genotype effect in the profile differentiation in this process.

Chewing Analysis by Means of Electromagnetic Articulography: Current Developments and New Possibilities.

Chewing is a complex procedure that involves sensory feedback and motor impulses controlled by the trigeminal system in the brainstem. The analysis of mandibular movement is a first approximation to understanding these mechanisms. Several recording methods have been tested to achieve this. Video, ultrasound, the use of external markers and kinesiographs are examples of recording systems used in research. Electromagnetic articulography is an alternative method to those previously mentioned. It consists of the use of electromagnetic fields and receiver coils. The receiver coils are placed on the points of interest and the 3D coordinates of movement are saved in binary files. In the Oral Physiology Laboratory of the Dental Sciences Research Center (Centro de Investigación en Ciencias Odontológicas-CICO), in the Faculty of Dentistry at the Universidad de La Frontera (Temuco, Chile) several research studies have been carried out using the AG501 3D EMA articulograph (Carstens Medizinelektronik, Lenglern, Germany). With this device, they developed a series of protocols to record mandibular movement and obtain new information, such as the 3D Posselt polygon, the area of each polygon, individualized masticatory cycles and speed and acceleration profiles. Other investigations have analyzed these parameters, but separately. The AG501 allows for holistic analysis of all these data without altering natural movement. A limitation of this technology is the interference generated by its metallic elements. The aim of the present work is to show the developed methods used to record mandibular movement in the CICO, using the AG501 and compare them with others used in several research studies.

Analysis of the Chemical Composition and Morphological Characterization of Tissue Osseointegrated to a Dental Implant after 5 Years of Function.

Osseointegration implies the coexistence of a biocompatible implant subjected to masticatory loads and living bone tissue adhered to its surface; this interaction is a critical process for the success of implants. The objective of this work is to analyze the osseoformation and osseointegration of a dental implant in operation for 5 years microscopically through morphological analysis of the surface and chemical composition through a variable pressure scanning electron microscope (VP-SEM) and energy dispersive X-ray spectrometry (EDX). The chemical composition and general characteristics of the structural morphology of random areas of the surfaces of an osseointegrated dental implant from an ex vivo sample were analyzed. On the surface of the implant free of bone tissue, titanium (TI) was mainly identified in the area of the implant threads and carbon (C) in the depth of the implant threads. Phosphorus (P), calcium (Ca), oxygen (O), carbon (C), with dense and homogeneous distribution, and, to a lesser extent, sodium (Na) were detected on the bone surface around the contour of the implant. Regarding the morphological characteristics of the implant surface, a rough structure with some irregularities and detachments of the implant lodged in the bone tissue was observed. Microscopic analysis showed calcified bone tissue distributed in an orderly manner on the coronal and medial surface and sinuous and irregular in the apical area, with the presence of red blood cells. The composition of the implant allows a dynamic process of bone remodeling and regeneration subject to the biological and mechanical needs of the operation. Dental implants are shown to have exceptional and long-lasting biocompatibility that enables the formation of mature peri-implant bone tissue.

Hardness Analysis of Foods in a Diet Based on the Mediterranean Diet and Adapted to Chilean Gastronomy.

The human diet is a factor for disease prevention and the extension of life expectancy. Loss of teeth can adversely affect chewing capacity, which can lead patients to modify their diet and subsequently result in a poor dietary intake. This work is conducted within the framework of an ongoing research project in the Dentistry School of Universidad de la Frontera aimed at designing a diet for patients with complete removable dental prostheses (CRDP). This study aimed to evaluate the hardness of foods in a diet designed for patients using CRDP, using texture profile analysis (TPA). TPA was used to measure the hardness of 43 foods, categorized into seven groups, dairy, animal protein, fruits, vegetables, cereals and grains, high-lipid foods, and vegetable protein, to understand their impact on masticatory performance in CRDP wearers. TPA consists of two compression cycles where the food sample is compressed until it reaches a pre-established deformation. The first force peak achieved in the first cycle is used as a measure of sample hardness. Significant differences in hardness were identified within each food group, indicating a wide spectrum of textural properties that could influence chewing behavior. These findings suggest that assessing food hardness can help tailor dietary recommendations to improve masticatory efficiency in patients with dental prostheses.

Determination of Micromovements in Removable Prosthesis during Mastication: A Pilot Study with 3D Electromagnetic Articulography.

Edentulism can generate negative impacts on self-esteem, interpersonal relationships, and oral functions. Removable prostheses are commonly used for tooth replacement, but they may cause discomfort due to micromovements during mastication. Objective and quantifiable methods are needed to evaluate these micromovements. A pilot study was conducted to determine the micromovements in removable prostheses during mastication using a 3D electromagnetic articulography (EMA-3D) system. One elderly participant wearing lower removable prostheses and an upper total well-fitting removable prosthesis was studied. The EMA-3D system was used to record movements in three spatial planes. Peanuts were given as test food, and the participant was instructed to chew normally while recordings were carried out until feeling the need to swallow. Analyses of the upper total prosthesis show micromovements ranging from 0.63 ± 0.11 to 1.02 ± 0.13 mm. During simultaneous analyses of the upper prosthesis and lower partial prosthesis, interference was not observed. This pilot study demonstrated the feasibility of using the EMA-3D system to evaluate micromovements in removable prostheses during mastication. Further research is needed to evaluate a larger sample and assess the clinical implications of these micromovements.

Monitoring Changes in Oxygen Muscle during Exercise with High-Flow Nasal Cannula Using Wearable NIRS Biosensors.

Exercise increases the cost of breathing (COB) due to increased lung ventilation (V˙E), inducing respiratory muscles deoxygenation (∇SmO2), while the increase in workload implies ∇SmO2 in locomotor muscles. This phenomenon has been proposed as a leading cause of exercise intolerance, especially in clinical contexts. The use of high-flow nasal cannula (HFNC) during exercise routines in rehabilitation programs has gained significant interest because it is proposed as a therapeutic intervention for reducing symptoms associated with exercise intolerance, such as fatigue and dyspnea, assuming that HFNC could reduce exercise-induced ∇SmO2. SmO2 can be detected using optical wearable devices provided by near-infrared spectroscopy (NIRS) technology, which measures the changes in the amount of oxygen bound to chromophores (e.g., hemoglobin, myoglobin, cytochrome oxidase) at the target tissue level. We tested in a study with a cross-over design whether the muscular desaturation of m.vastus lateralis and m.intercostales during a high-intensity constant-load exercise can be reduced when it was supported with HFNC in non-physically active adults. Eighteen participants (nine women; age: 22 ± 2 years, weight: 65.1 ± 11.2 kg, height: 173.0 ± 5.8 cm, BMI: 21.6 ± 2.8 kg·m-2) were evaluated in a cycle ergometer (15 min, 70% maximum watts achieved in ergospirometry (V˙O2-peak)) breathing spontaneously (control, CTRL) or with HFNC support (HFNC; 50 L·min-1, fiO2: 21%, 30 °C), separated by seven days in randomized order. Two-way ANOVA tests analyzed the ∇SmO2 (m.intercostales and m.vastus lateralis), and changes in V˙E and ∇SmO2·V˙E-1. Dyspnea, leg fatigue, and effort level (RPE) were compared between trials by the Wilcoxon matched-paired signed rank test. We found that the interaction of factors (trial × exercise-time) was significant in ∇SmO2-m.intercostales, V˙E, and (∇SmO2-m.intercostales)/V˙E (p < 0.05, all) but not in ∇SmO2-m.vastus lateralis. ∇SmO2-m.intercostales was more pronounced in CTRL during exercise since 5' (p < 0.05). Hyperventilation was higher in CTRL since 10' (p < 0.05). The ∇SmO2·V˙E-1 decreased during exercise, being lowest in CTRL since 5'. Lower dyspnea was reported in HFNC, with no differences in leg fatigue and RPE. We concluded that wearable optical biosensors documented the beneficial effect of HFNC in COB due to lower respiratory ∇SmO2 induced by exercise. We suggest incorporating NIRS devices in rehabilitation programs to monitor physiological changes that can support the clinical impact of the therapeutic intervention implemented.

Brief report: The sensitivity of motor responses for detecting catheter-nerve contact during ultrasound-guided femoral nerve blocks with stimulating catheters.

BACKGROUND: We determined the sensitivity of motor responses evoked by stimulating catheters in determining catheter-nerve contact using ultrasonography as reference. METHODS: Femoral nerves were contacted using stimulating catheters under ultrasonography scanning in 25 patients. The output current was increased from its minimum until quadriceps muscle contraction occurred. The sensitivity of the motor response in determining catheter-nerve contact was calculated using 0.5 mA as current threshold. RESULTS: The current required for catheter stimulation to evoke a motor response ranged between 0.18 and 2.0 mA. Muscle contraction in response to 0.5 mA occurred in 16 of 25 subjects. The sensitivity of motor response for nerve stimulation was 64% (95% confidence interval: 0.43, 0.82). CONCLUSIONS: The absence of muscle responses at a stimulating current≤0.5 mA does not necessarily indicate the absence of catheter-nerve contact.

A new insight of Platelet-Rich Fibrin clots morphology and their elemental composition.

This study analyzed the architecture of Platelet-Rich Fibrin (PRF) clots and assessed their elemental composition in order to provide new insight into this biomaterial. Five surplus PRF clots (2,700 RPM, 12 min.) donated by patients (63.6 ±â€¯12.3 years old) were prepared for use in dental clinical procedures. The internal three-dimensional morphology of the red zones and the thirds of the yellow zones of the clots were analyzed by Variable Pressure Scanning Electron Microscope (VPSEM) after sample preparation by two methods: 1. Fixation (2.5% gluataraldehyde); and 2. Fixation with subsequent partial removal of extracellular elements (8 N, HCl). Semi-quantitative elemental analysis was performed by energy-dispersive X-ray spectrometry (EDX). VPSEM analysis showed erythrocytes in both the red zone and the yellow zone, which consisted mainly of fibrin. Removal of extracellular elements enriched the morphology of both zones; the organization of the fibrin was observed to differ in the thirds of the yellow zone, with increasing density and organization to distal. The elements that compose organic substances (C-Carbon, N-Nitrogen, O-Oxygen, Na-Sodium and P-Phosphorus) and halogens (Cl-Chloride and S-Sulfur) were detected; the highest concentrations were of C, followed by O (p < 0.05), in the proximal region of the fibrin. The results of the present study suggest organization of fibrin in the PRF clot, and also reveal the distribution of the elements present in the different regions of the clot. Improved understanding of these characteristics may favor the use of this biomaterial by increasing its efficiency and functionality.

GLUT1 and GLUT8 support lactose synthesis in Golgi of murine mammary epithelial cells.

The mammary gland increases energy requirements during pregnancy and lactation to support epithelial proliferation and milk nutrients synthesis. Lactose, the principal carbohydrate of the milk, is synthetized in the Golgi of mammary epithelial cells by lactose synthase from glucose and UPD galactose. We studied the temporal changes in the expression of GLUT1 and GLUT8 in mammary gland and their association with lactose synthesis and proliferation in BALB/c mice. Six groups were used: virgin, pregnant at 2 and 17 days, lactating at 2 and 10 days, and weaning at 2 days. Temporal expression of GLUT1 and GLUT8 transporters by qPCR, western blot and immunohistochemistry, and its association with lactalbumin, Ki67, and cytokeratin 18 within mammary tissue was studied, along with subcellular localization. GLUT1 and GLUT8 transporters increased their expression during mammary gland progression, reaching 20-fold increasing in GLUT1 mRNA at lactation (p < 0.05) and 2-fold at protein level for GLUT1 and GLUT8 (p < 0.05 and 0.01, respectively). The temporal expression pattern was shared with cytokeratin 18 and Ki67 (p < 0.01). Endogenous GLUT8 partially co-localized with 58 K protein and α-lactalbumin in mammary tissue and with Golgi membrane-associated protein 130 in isolated epithelial cells. The spatial-temporal synchrony between expression of GLUT8/GLUT1 and alveolar cell proliferation, and its localization in cis-Golgi associated to lactose synthase complex, suggest that both transporters are involved in glucose uptake into this organelle, supporting lactose synthesis.

Área de Céntrica, Revisión del Concepto. Una Revisión Narrativa / Central Area, Review of the Concept. A Narrative Review

La búsqueda de una oclusión ideal es uno de los principales objetivos de los tratamientos rehabilitadores. Para que esta se cumpla, es necesario que se presenten ciertas características, en base a esto, se ha constituido el concepto de "tríada en céntrica", que se define como la coincidencia entre la relación céntrica fisiológica (RCF), posición muscular de contacto (PMC) y posición de máxima intercuspidación (PMI), existiendo de esta forma un equilibrio morfofuncional óptimo de los diferentes componentes del sistema estomatognático. Así nace la necesidad de analizar los conceptos que involucren la relación existente entre las distintas posiciones mandibulares, dentro de estos conceptos encontramos el "área de céntrica", que debido a sus características, se le atribuye relevancia y utilidad clínica cuando se entiende su aplicación. El objetivo de este estudio fue analizar el concepto de área céntrica, actualizar los conceptos oclusales asociados y proponer nuevas metodologías para su evaluación. En ocasiones existen interferencias oclusales que impiden que la mandíbula continúe su recorrido habitual para llegar a determinada posición, estas interferencias se conocen como contactos prematuros, cuando estos existen, naturalmente la mandíbula se desvía hacia una posición de acomodo. El deslizamiento en céntrica se define como el movimiento de la mandíbula mientras se encuentra posición retruida de contacto no forzada, es decir, la posición de contacto que se produce cuando la mandíbula se cierra en RCF, hasta llegar a PMI, este deslizamiento se produce debido a la presencia de contactos prematuros, cuando no existen contactos prematuros, esta posición coincidirá con PMI. El área de céntrica se define como el deslizamiento de la mandíbula entre la posición retruída ligamentosa (PRL) y PMI. Idealmente, la PMI se da cuando los cóndilos están en RCF y coincide con la PMC, debe existir siempre un área de céntrica, pues fisiológicamente ninguna articulación adoptara naturalmente una posición extrema como la PRL.

The search for an ideal occlusion is one of the main objectives of rehabilitation treatments. For this to be fulfilled, some characteristics need to be present, based on this, the concept of "centric triad" has been constituted, which is defined as the coincidence between the physiological centric relation (CR), muscular contact position (MCP) and maximum intercuspal position (MIP), thus existing an optimal morphofunctional balance of the different components of the stomatognathic system. In this way, the need arises to analyze the concepts that involve the relationship between the different mandibular positions, within these concepts we find the "centric area", which due to its characteristics, it is attributed relevance and clinical utility when its application is understood. The objective of this study was to analyze the concept of centric area, update the associated occlusal concepts and propose new methodologies for its evaluation. Sometimes there are occlusal interferences that prevent the jaw from continuing its usual path to reach a certain position, these interferences are known as premature contacts, when they exist, the jaw naturally deviates towards a position of accommodation. Centric slide is defined as the movement of the mandible when it is in a retruded contact position unforced, that is, the contact position that occurs when the mandible closes in CR, until reaching MIP, this sliding occurs due to in the presence of premature contacts, when there are no premature contacts, this position will coincide with PMI. The centric area is defined as the slippage of the mandible between the retruded ligamentous position (RLP) and MIP. Ideally, the PMI occurs when the condyles are in CR and coincides with the MCP, there should always be a centric area, since physiologically no joint will naturally adopt an extreme position like PRL.

Una Revisión de los tipos de Fraude Científico más Frecuentes / A Review of the most frequent types of Scientific Fraud

La presión que existe hoy por publicar ha llevado a que muchos investigadores cometan malas conductas científicas, siendo el fraude la más grave de todas. Este ocurre en forma de fabricación, falsificación, plagio, problemas de autoría, manipulación de imágenes y publicaciones redundantes. El fraude científico se define como una tergiversación deliberada por parte de alguien que conoce la verdad. En la historia de la humanidad se han conocido importantes casos de fraude científico, dentro de ellos se pueden destacar: el hombre de Piltdown, caso Shinichi Fujimura, el escándalo de las vacunas, caso Pearce, el caso Yoshitaka Fujii, entre otros. Con el objetivo de neutralizar el fraude, se han desarrollado diferentes estrategias dirigidas a detectarlo, dentro de ellas encontramos: evaluación mediante pares evaluadores, programas de Conducta de Investigación Responsable (RCR), regulaciones que la misma comunidad científica realiza, donde encontramos la fundación PubPeer y el blog For Better Science. Del mismo modo, se han impuesto diferentes medidas para contrarrestar el fraude, tales como: transparencia de las presiones y oportunidades, disponibilidad pública de los datos que sustentan la hipótesis y denuncia pública de los fraudes científicos. El impacto de un fraude trae consecuencias importantes para la ciencia, estudiar a partir de información falsa o errónea conlleva a un gran retroceso en los avances científicos del mundo actual. Es responsabilidad de cada uno ser consciente de lo que se escribe y lo que se lee, ya que como se sabe, esa es la única manera de combatirlo. Como investigadores somos responsables de actuar éticamente en nuestras investigaciones y tener conocimiento de las medidas que existen hoy para detectar y combatir el fraude científico.

The pressure to publish today has led many researchers to commit scientific misconduct, fraud being the most serious of all. This occurs in the form of fabrication, falsification, plagiarism, authorship problems, image manipulation, and redundant posting. Scientific fraud is defined as deliberate misrepresentation by someone who knows the truth. In the history of humanity, important cases of scientific fraud have been known, among them the following can be highlighted: the Piltdown man, the Shinichi Fujimura case, the vaccine scandal, the Pearce case, the Yoshitaka Fujii case, among others. In order to neutralize fraud, different strategies have been developed to detect it, among them we find: evaluation by peer reviewers, Responsible Research Conduct (RCR) programs, regulations that the scientific community itself carries out, where we find the PubPeer Foundation and the For Better Science blog. Similarly, different measures have been imposed to counteract fraud, such as: transparency of pressures and opportunities, public availability of the data that support the hypothesis, and public denunciation of scientific fraud. The impact of a fraud has important consequences for science, studying from false or wrong information leads to a great setback in scientific advances in the world today. It is the responsibility of each one to be aware of what is written and what is read, since as is known, that is the only way to combat it. As researchers we are responsible for acting ethically in our research and being aware of the measures that exist today to detect and combat scientific fraud.

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.

Indigenous ecological calendars and seasonal vector-borne diseases in the Colombian Amazon: an intercultural and interdisciplinary approach / Calendarios ecológicos indígenas y enfermedades estacionales transmitidas por vectores en la Amazonia colombiana: un enfoque intercultural e interdisciplinario

Traditional ecological knowledge of indigenous groups in the southeastern Colombian Amazon coincides in identifying the two main hydrological transition periods (wet-dry: August-November; dry-wet: March-April) as those with greater susceptibility to disease in humans. Here we analyze the association between indigenous knowledge about these two periods and the incidence of two vector-borne diseases: malaria and dengue. We researched seven "ecological calendars" from three regions in the Colombian Amazon, malaria and dengue cases reported from 2007 to 2019 by the Colombian National Institute of Health, and daily temperature and precipitation data from eight meteorological stations in the region from 1990-2019 (a climatological normal). Malaria and dengue follow a seasonal pattern: malaria has a peak from August to November, corresponding with the wet-dry transition (the "season of the worms" in the indigenous calendars), and dengue has a peak in March and April, coinciding with the dry-wet transition. Previous studies have shown a positive correlation between rainfall and dengue and a negative correlation between rainfall and malaria. However, as the indigenous ecological knowledge codified in the calendars suggests, disease prediction cannot be reduced to a linear correlation with a single environmental variable. Our data show that two major aspects of the indigenous calendars (the time of friaje as a critical marker of the year and the hydrological transition periods as periods of greater susceptibility to diseases) are supported by meteorological data and by the available information about the incidence of malaria and dengue.(AU)

Los conocimientos ecológicos tradicionales de grupos indígenas del sureste de la Amazonia colombiana coinciden en identificar dos principales periodos de transición hidrológica (seco-húmedo: agosto-noviembre; húmedo-seco: marzo-abril) como los de mayor susceptibilidad a enfermedades en humanos. Aquí analizamos la asociación entre el conocimiento indígena sobre estos dos periodos y la incidencia de dos enfermedades transmitidas por vectores: malaria y dengue. Investigamos siete calendarios ecológicos de tres regiones en la Amazonia colombiana, casos de dengue y malaria reportados de 2007 hasta 2019 por el Instituto Nacional de Salud de Colombia y datos diarios de temperatura y precipitación de ocho estaciones meteorológicas en la región, de 1990 a 2019 (una normal climatológica). Malaria y dengue siguen un patrón estacional, la malaria tiene un pico de agosto a noviembre, correspondiendo con la transición húmedo-seco (el "tiempo de gusano" según los calendarios indígenas), mientras que dengue tiene un pico de marzo a abril, coincidiendo con la transición seco-húmedo. Estudios previos mostraron una correlación positiva entre precipitación y dengue, y una correlación negativa entre precipitación y malaria. Sin embargo, como lo sugiere el conocimiento ecológico codificado en los calendarios indígenas, la predicción de enfermedades no puede reducirse a una correlación lineal con una sola variable medioambiental. Nuestros datos muestran que dos aspectos principales de los calendarios indígenas (el tiempo de friaje como un marcador crítico anual y los periodos de transición hidrológica como épocas de mayor susceptibilidad a enfermedades) están soportados por datos meteorológicos e información disponible acerca de la incidencia de malaria y dengue.(AU)

Masticatory function according to body mass index: part II: electromyographic analysis / Función masticatoria según índice de masa corporal: parte II: análisis electromiográfico

Introduction: The objective of this study was to explore the electrical activity of the superficial muscles of mastication required to exert unilateral maximum bite force in subjects with different body mass index. Material and Methods: A cross-sectional observational study was conducted with a sample of 21 participants with an average age of 22.9 ± 3.5 years who were classified according to their body mass index, forming three study groups: normal weight (18.5-24.9), overweight (25-29.9) and obesity (≥30), with seven participants each. Through surface electromyography, the superficial muscles of mastication during right and left maximum bite force were evaluated. Results: No statistically significant differences in the maximum bite force were observed between the study groups. The data obtained from the electromyographic analysis of the superficial muscles of mastication demonstrate a trend indicating that subjects with a normal body mass index similarly activate the muscles on each side when performing a maximum bite force on a particular side, while overweight or obese subjects demonstrated significantly greater activation of the temporalis muscle associated with the side where the maximal bite force is performed. Conclusion: Our findings suggest that the maximum bite force is not influenced by body mass index and that during the performance of a maximum bite force subjects with increased body mass index present a greater activation of the temporalis muscle associated with the side where the maximum bite force was performed.

Introducción: El objetivo de este estudio fue explorar la actividad eléctrica de los músculos superficiales de la masticación, necesarios para ejercer la máxima fuerza de mordida unilateral, en sujetos con diferente índice de masa corporal. Material y Métodos: Se realizó un estudio observacional de corte transversal con una muestra de 21 participantes con una edad promedio de 22.9 ± 3.5 años, quienes fueron clasificados de acuerdo a su índice de masa corporal, formando tres grupos de estudio: peso normal (18,5-24,9), sobrepeso (25,0-29,9) y obesidad (≥30.0), con siete participantes cada uno. La electromiografía de superficie evaluó los músculos superficiales de la masticación durante la fuerza de mordida máxima derecha e izquierda. Resultados: No se observaron diferencias estadísticamente significativas en la fuerza de mordida máxima entre los grupos de estudio. Los datos obtenidos del análisis electromiográfico de los músculos superficiales de la masticación demuestran una tendencia que indica que los sujetos con un índice de masa corporal normal activan de manera similar los músculos de cada lado cuando ejercen la fuerza de mordida máxima en un lado en particular. mientras que los sujetos con sobrepeso u obesos demostraron una activación significativamente mayor del músculo temporal asociado con el lado donde se realiza la fuerza máxima de mordida. Conclusión: Nuestros hallazgos sugieren que la fuerza de mordida máxima no está influenciada por el índice de masa corporal y que durante la realización de una fuerza de mordida máxima los sujetos con índice de masa corporal aumentado presentan una mayor activación del músculo temporal asociado al lado donde se realizó la fuerza de mordida máxima.

Masticatory function according to body mass index: part I: kinematic analysis using different food textures / Función masticatoria según índice de masa corporal: parte I: análisis cinemático utilizando diferentes texturas de alimentos

Introduction: Chewing is a learned orofacial function, important in the nutrition process of most mammals. It has been described that it can vary according to the characteristics of the individuals and the characteristics of the food. The aim of this study was to compare the kinematic characteristics of mastication in subjects with different body mass index (BMI), including foods of different hardness in the analysis. Material and Methods: A cross-sectional observational study was conducted. The mastication of 3.7 g of peanut (soft food) and 3.7 g of carrot (hard food) was compared among three study groups formed according to BMI: normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9) and obese (BMI ≥30); each with 7 participants. The kinematics of the masticatory movement were assessed with a 3D Electromagnetic Articulograph, the characteristics analyzed were number of masticatory cycles, masticatory frequency, speed and area of the cycles. Results: No significant differences were noted among the study groups for the number of masticatory cycles, frequency or speed in the two foods studied. It was observed that when chewing carrot, the horizontal area of the masticatory cycles was significantly larger in the obese than in the overweight group. However, when chewing peanuts, this parameter did not present significant differences among the different groups. A comparison of the characteristics of mastication of the two foods revealed that the carrot chewing presented a significantly greater masticatory frequency and speed than the peanut chewing. Conclusion: This study demonstrated that food hardness influences the kinematic characteristics of mastication more than BMI, noting that hard foods are masticated faster and more frequently than soft foods and that masticatory frequency tends to increase with BMI.

Introduction: Chewing is a learned orofacial function, important in the nutrition process of most mammals. It has been described that it can vary according to the characteristics of the individuals and the characteristics of the food. The aim of this study was to compare the kinematic cha-racteristics of mastication in subjects with different body mass index (BMI), including foods of different hardness in the analysis. Material and Methods: A cross-sectional observational study was con- ducted. The mastication of 3.7 g of peanut (soft food) and 3.7 g of carrot (hard food) was compared among three study groups formed according to BMI: normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9) and obese (BMI ?30); each with 7 participants. The kinematics of the masticatory movement were assessed with a 3D Electromagnetic Articulograph, the characteristics analyzed were number of masticatory cycles, masticatory frequency, speed and area of the cycles. Results: No significant differences were noted among the study groups for the number of masticatory cycles, frequency or speed in the two foods studied. It was observed that when chewing carrot, the horizontal area of the masticatory cycles was significantly larger in the obese than in the overweight group. However, when chewing peanuts, this parameter did not present significant differences among the different groups. A comparison of the characteristics of mastication of the two foods revealed that the carrot chewing presented a significantly greater masticatory frequency and speed than the peanut chewing. Conclusion: This study demonstrated that food hardness influences the kinematic characteristics of mastication more than BMI, noting that hard foods are masticated faster and more frequently than soft foods and that masticatory frequency tends to increase with BMI.

Effect of chewing behavior modification on food intake, appetite and satiety-related hormones: A Systematic Review

Purpose: Obesity has become a growing public health issue worldwide. Studies have shown that eating rate is one of the most important factors to consider in the strategies to prevent and/or treat obesity. Eating rate can be reduced through different strategies, such as an increase in oro-sensory exposure, the modification of food texture, and an increase in the number of chewing cycles. The aim of this systematic review was to analyze the available evidence regarding the effect of chewing behavior modification on the parameters that contribute to obesity. Methods: A systematic search was done on the electronic databases Pubmed, Cochrane Central Register of Controlled Trials, and Scopus, using the terms "mastication", "chewing", "chewing speed", "prolonged chewing", "number of chews", "masticatory cycles" "satiety" "satiety response" "appetite", "appetite regulation", "nutritional status" and "obesity". Results: A total of 23 intervention studies were selected that intervened in the participants' chewing behavior, either by reducing the eating rate, increasing oro-sensory exposure, food hardness or the number of chewing cycles. In most studies these interventions were effective at reducing food intake, subjective appetite and improving the plasma levels of satiety-related hormones and metabolites; moreover, they reduced body mass index in the long term. Conclusion: The currently available evidence seems to indicate that modifications to chewing behavior can bring with it a myriad of benefits for the treatment of obesity.

Propósito: La obesidad se ha convertido en un problema de salud pública creciente a nivel mundial. Investigaciones han demostrado que la tasa de ingesta es uno de los factores importantes a considerar en las estrategias para prevenir o tratar la obesidad. La tasa de ingesta puede reducirse a través de diferentes estrategias; el aumento de la exposición oro-sensorial, la modificación de la textura de los alimentos y el aumento en el número de ciclos masticatorios. El objetivo de esta revisión sistemática fue analizar la evidencia disponible sobre el efecto de la modificación de la conducta masticatoria sobre los parámetros que contribuyen a la obesidad. Métodos: Se realizó una búsqueda sistemática en las bases de datos electrónicas Pubmed, Cochrane Central Register of Controlled Trials y Scopus, con los términos "mastication", "chewing", "chewing speed", "prolonged chewing", "number of chews", "masticatory cycles" "satiety" "satiety response" "appetite", "appetite regulation", "nutritional status" y "obesity". Resultados: Se seleccionaron 23 estudios que intervenían en el comportamiento masticatorio de los participantes, ya sea reduciendo de la tasa de ingesta, aumentando la exposición oro-sensorial, dureza de los alimentos y número de ciclos masticatorios. Estas intervenciones resultaron ser efectivas para reducir la ingesta de alimentos, el apetito subjetivo y mejorar los niveles plasmáticos de las hormonas y metabolitos relacionados con la saciedad, además, a largo plazo, permitieron reducciones en el índice de masa corporal. Conclusión: La evidencia disponible actualmente parece señalar que las modificaciones en el comportamiento masticatorio pueden traer consigo múltiples beneficios para el tratamiento de la obesidad.

Características morfométricas de la mandíbula de rata: un estudio radiológico de un modelo experimental animal ampliamente utilizado a través de CBCT / Morphometric characteristics of rat mandibular bone: radiologic study of a widely used animal as experimental model through CBCT

La mandíbula de rata es una de las estructuras anatómicas de mayor interés en la investigación en las ciencias odontológicas, esto debido a su similitud con la mandíbula humana. El objetivo de este estudio fue caracterizar morfometricamente la mandíbula de ratas mediante CBCT. Se analizó el examen cone beam de 20 ratas hembras, adultas sanas. Mediante el software del examen, fue posible aislar la mandíbula derecha e izquierda de las otras estructuras y realizar adecuadamente las medidas morfométricas de interés. En la comparación de ambos lados, sólo dos medidas presentaron diferencias significativas. La distancia entre el punto más profundo de la escotadura sigmoidea hasta el punto más profundo de la escotadura en el margen inferior de la mandíbula, fue mayor en el lado izquierdo que en el derecho. Y la distancia entre el punto más superior del cóndilo hasta la base mandibular, en la proyección perpendicular del plano mandibular fue mayor en el lado izquierdo que en el derecho. De acuerdo a las medidas obtenidas, podemos determinar que la mandíbula de la rata es una estructura alargada, con dimensiones mayores en sentido anteroposterior en comparación con las medidas verticales. El conocimiento de la anatomía de la mandíbula de rata y sus variaciones por lado permite a los investigado- res tener referencias adecuadas para los estudios que involucren esta estructura, como por ejemplo, investigaciones que requieran la aplicación de técnicas anestésicas, estudio del dolor orofacial, estudio patofisiológico de la ATM, estudio del crecimiento óseo, testeo de biomateriales dentales o en el estudio de procesos fisiopatológicos relacionados con los tejidos dentales o periodontales. La mandíbula de la rata es un buen modelo animal debido a su reproducibilidad y bajo costo. La mandíbula derecha e izquierda son similares en sus dimensiones anteroposteriores, pero no las verticales.

SUMMARY: The rat jaw is one of the most interesting anatomical structures in dental science research, due to its similarity to the human jaw. The aim of this study was to morphometrically characterize the mandible of rats by CBCT. The cone beam examination of 20 healthy adult female rats was analyzed. Using the examination software, it was possible to isolate the right and left mandible from the other structures and adequately perform the morphometric measurements of interest. In the comparison of both sides, only two measures presented significant differences. The distance from the deepest point of the sigmoid notch to the deepest point of the notch at the lower margin of the mandible was greater on the left side than on the right. And the distance between the most superior point of the condyle to the mandibular base, in the perpendicular projection of the mandibular plane, was greater on the left side than on the right. According to the measurements obtained, we can determine that the rat jaw is an elongated structure, with larger dimensions in the anteroposterior direction compared to the vertical measurements. Knowledge of the anatomy of the rat mandible and its variations per side allows researchers to have adequate references for studies involving this structure, such as research that requires the application of anesthetic techniques, study of orofacial pain, pathophysiological study of the TMJ, study of bone growth, testing of dental biomaterials or in the study of pathophysiological processes related to den- tal or periodontal tissues. The rat mandible is a good animal model due to its reproducibility and low cost. The right and left mandible are similar in their anteroposterior dimensions, but not the vertical ones.

Posiciones Mandibulares de Referencia Clínica: una Descripción Narrativa / Mandibular Positions of Clinical Reference: narrative description

Las posiciones mandibulares se definen como la relación existente entre la mandíbula y la maxila observada durante su función, o bien posiciones de referencia clínica que pueden ser comparables con otras posiciones o movimientos. Se realizó una descripción narrativa de las posiciones de referencia mandibular de mayor interés clínico, donde se definen algunas de sus principales características; (1) la posición de máxima intercuspidación, está definida por el determinante anatómico dentario, tiene una adecuada reproducibilidad y sencilla ejecución, (2) la posición postural mandibular, es la menos estable, y está definida por el determinante fisiológico neuromuscular, siendo el resultado de la interacción de múltiples factores relacionados, (3) la relación céntrica fisiológica, se considera la posición más estable de la mandíbula, siendo repetible e independiente del contacto dentario, (4) la posición retruida ligamentosa, es una posición extrema por lo que no se considera fisiológica, está determinada por la tensión de la banda horizontal medial del ligamento temporomandibular, (5) la posición retruida de contacto, se describe como la posición mandibular cuando se producen los primeros contactos dentarios y la articulación temporomandibular (ATM) está en una posición retruida, se divide en forzada y no forzada, (6) la posición muscular de contacto es una posición regulada a través de diferentes mecanismos que permiten su estabilidad. Estas posiciones brindan una referencia clínica por medio de la cual se pueden evaluar distintos parámetros necesarios para de realizar diagnósticos y planificación de tratamientos, para ello es importante que el profesional tenga los conocimientos adecuados sobre las características que definen cada una de ellas, tales como su estabilidad y reproducibilidad, que son fundamentales al momento de su ejecución.

Mandibular positions are defined as the existing relation between mandibula and maxilla during its function, or it can also be defined as clinical reference positions that may be comparable with other positions or movements. A narrative description of the mandibular reference positions of greatest clinical interest was made, where some of their main characteristics were defined; (1) maximum intercuspal position, is defined by de dental anatomical determinant, it has an adequate reproduction and simple execution, (2) the mandibular postural position, it is the least stable, and it is defined by the neuromuscular physiological elements, being the result of the interaction of multiple factors related, (3) the physiological centric relation is considered the most stable position of the mandible, being easy to repeat and independent of dental contact, (4) the retruded ligamentous position, is an extreme position so it is not considered physiological, and it is determinated by the tension of the medial horizontal band of the temporomandibular ligament, (5) retruded contact position is described as the mandibular position when the first dental contacts are produced and the temporomandibular joint (TMJ) is in a retruded position, it is divided into forced and non- forced, (6) the muscular contact position is a position regulated through different mechanisms that allows its stability. These positions provide a clinical reference by means of which different parameters required while diagnosing and planning treatments can be evaluated, this is why it is important for the Specialist to have specific knowledge about the characteristics that correspond to each one of them, such as its stability and reproducibility, which are fundamental at the time of its execution.