Mandibular border movements: The two envelopes of motion.

BACKGROUND: The envelope of motion is a diagrammatic representation of the mandibular border movements. Classically, those movements are carried out eccentrically; starting from the position of maximal intercuspation, the mandible describes an excursion movement until reaching maximal mouth opening. Reverse movements would describe a different path, but up to now concentric development of mandibular border movements has not been considered. Literature states that beyond mandibular border movements limits, no movement is possible. Therefore, it is of great interest to compare both paths-both envelopes of motion-and define the actual limits of mandibular movement. OBJECTIVE: The aim of this study was to compare the geometric characteristics of mandibular border movements carried out eccentrically and concentrically by healthy subjects. METHODS: Sixteen individuals aged between 18 and 27 years, molar class I and with no temporomandibular disorders, participated in the study. Eccentric and concentric mandibular movements were recorded using a 3D electromagnetic articulograph. Data were processed with computational scripts developed in MATLAB. Maximum mouth opening, trajectories, displacement ranges, polygon areas and chewing cycle area/ mandibular border movements area ratio were analysed. RESULTS: The frontal plane showed significant differences in all the parameters evaluated. Higher values were registered in the concentric area of the border movement envelope (P = .008) and in the trajectories on both sides. Statistical differences were observed in polygon areas (P = .006) in the sagittal plane and right ranges (P = .046) in the horizontal plane. CONCLUSION: Concentric mandibular movements revealed significant differences in three-dimensional trajectories in the frontal plane.

Accuracy and Reliability of AG501 Articulograph for Mandibular Movement Analysis: A Quantitative Descriptive Study.

Electromagnetic articulography (EMA) have been mostly employed to study articulatory movements of speech. This technology appears to be very promising for studying mandibular movements within the field of dentistry. However, there are no studies reporting the validity of EMA for such purpose. The aim of this study is to assess accuracy and reliability of Carstens three-dimensional EMA AG501 in order to validate its use for mandibular movement analysis in dentistry. A set of tests was conducted attaching 16 sensors to a rotating rigid structure placed inside the measurement area. Another set of tests were conducted using a mouth anatomical model with human-like articulatory behaviour. A function of the EMA system called "head correction" was applied to normalize the data of every recording. The system reliability was higher at the centre of the measurement area and decreased toward the edges. Dispersion was greater for raw data than for normalized data. Bland-Altman analysis of agreement between the AG501 and a millimetre ruler used to measure the distance between the sensors revealed limits of agreement between 0.5 mm and -0.9 mm. The results suggest that EMA AG501 is valid for three-dimensional analysis of mandibular biomechanics allowing natural movements.

A Novel Three-Dimensional Analysis of Tongue Movement During Water and Saliva Deglutition: A Preliminary Study on Swallowing Patterns.

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 3D-electromagnetic 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 ½-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 ½-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.

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.

Description of tongue movements on swallowing patterns.

OBJECTIVE: The purpose of this study was to compare the different swallowing patterns regarding tongue movement during saliva swallowing in healthy participants. DESIGN: Seventeen participants (23.0 ± 3.6 years old) were included in this cross-sectional study. The movement of the tongue (anterior, middle and posterior portions) on the three axes of space (inferior-superior, anterior-posterior and medial-lateral) was recorded using a 3D electromagnetic articulograph. The tongue movement patterns registered during saliva swallowing were classified according to Bourdiol et al. (2014) into Type I, II or III. RESULTS: Three swallowing patterns were identified (Type I, 64.7 %; Type II, 5.9 %; and Type III, 29.4 %). On the anterior-posterior axis, the displacement of the three portions of the tongue was significantly higher in Type III pattern compared with the Type I pattern. Furthermore, on the superior-inferior axis, the displacement of the anterior portion was significantly higher in Type III pattern compared with Type I pattern. In Type I pattern, on the inferior-superior axis, the smallest range of displacement occurred in the anterior portion of the tongue, followed by the middle and, finally, the posterior portion. In the analysis of Type III swallowing pattern, no significant differences were found on the range of displacement of the tongue portions on the three axes. CONCLUSION: Statistical differences were found between swallowing patterns Type I and III regarding tongue movement. The frequency of pattern II found in the participants of this study was not high enough to compare the three patterns. However, the results obtained indicate that the methodology applied could be used to identify the patterns based on quantitative data.

Platelet-rich fibrin and collagen membrane in the preservation of the alveolar bone: Feasibility of the elemental inorganic composition and scanning electron microscopy analysis.

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.

Mastication as a protective factor of the cognitive decline in adults: A qualitative systematic review.

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.

Targeting Autophagy for Cancer Treatment and Tumor Chemosensitization.

Autophagy is a tightly regulated catabolic process that facilitates nutrient recycling from damaged organelles and other cellular components through lysosomal degradation. Deregulation of this process has been associated with the development of several pathophysiological processes, such as cancer and neurodegenerative diseases. In cancer, autophagy has opposing roles, being either cytoprotective or cytotoxic. Thus, deciphering the role of autophagy in each tumor context is crucial. Moreover, autophagy has been shown to contribute to chemoresistance in some patients. In this regard, autophagy modulation has recently emerged as a promising therapeutic strategy for the treatment and chemosensitization of tumors, and has already demonstrated positive clinical results in patients. In this review, the dual role of autophagy during carcinogenesis is discussed and current therapeutic strategies aimed at targeting autophagy for the treatment of cancer, both under preclinical and clinical development, are presented. The use of autophagy modulators in combination therapies, in order to overcome drug resistance during cancer treatment, is also discussed as well as the potential challenges and limitations for the use of these novel therapeutic strategies in the clinic.

Multicenter study of patients' preferences and concerns regarding the origin of bone grafts utilized in dentistry.

PURPOSE: Bone graft materials can be obtained from the patient's own body (autologous graft), animals (xenograft), human cadavers (allograft) and synthetic materials (alloplastic bone graft). Patients may have ethical, religious or medical concerns about the origin of bone grafts, which could lead them to reject the use of certain types of bone graft in their treatments. The aim of this multicenter study, which surveyed patients from five university clinics in Portugal, France, Italy, Spain and Chile, was to analyze patients' opinions regarding the source of bone grafts. PATIENTS AND METHODS: A survey composed of ten questions was translated into local languages and validated. Patients were asked about the degree of acceptance/rejection of each graft and the reasons for rejection. A chi-squared test was used to analyze statistically significant differences. RESULTS: Three hundred thirty patients were surveyed. The grafts that elicited the highest percentage of refusal were allograft (40.4%), autologous bone graft from an extraoral donor site (34%) and xenograft (32.7%). The grafts with the lowest rate of refusal were alloplastic (6.3%) and autologous bone grafts from an intraoral donor site (24.5%). The main reason for autologous bone rejection was the fear of pain and discomfort, for xenograft it was the fear of disease transmission and the rejection of use of animals for human benefit, and for allograft it was ethical/moral motivations and the fear of disease transmission. Religious affiliation influenced patient's preferences. CONCLUSION: The origin of bone grafts is still conflictive for a high percentage of patients.

A New Tridimensional Insight into Geometric and Kinematic Characteristics of Masticatory Cycles in Participants with Normal Occlusion.

The aim of this study was to analyze the general, geometric, and kinematic characteristics of the masticatory cycle's movements in a tridimensional way, using a method developed by our study group to provide a new insight into the analysis of mandibular movements due to advancement in the potential of computational analysis. Ten individuals (20.1 ± 2.69 years), molar class I, without mandibular movement problems participated in this study. The movements of the masticatory cycles, frontal and sagittal mandibular border movements, were recorded using 3D electromagnetic articulography and processed with computational scripts developed by our research group. The number of chewing cycles, frequency (cycles/s), chewing cycle areas/mandibular border movements areas ratios, and the mouth opening and closing speeds on the 3D trajectory of the chewing cycle were compared. The cycles were divided and analyzed in thirds. The masticatory cycles showed high variation among the individuals (21.6 ± 9.4 cycles); the frequency (1.46 ± 0.21 cycles/s) revealed a moderate positive correlation (R = 0.52) with the number of cycles. The frontal area ratios between the cycle area and the mandibular border movement presented higher values in the first third (6.65%) of the masticatory cycles, and the ratios of sagittal areas were higher and more variable (first, 7.67%; second, 8.06%; and third, 10.04%) than the frontal view. The opening and closing mouth speeds were greater in the second third of the masticatory cycles (OS, 57.82 mm/s; CS, 58.34 mm/s) without a significant difference between the opening and closing movements when the same thirds were evaluated. Further studies are necessary to improve the understanding of the masticatory cycles regarding the standardization of parameters and their values.

Prevalence of radix entomolaris in mandibular first molars by cone-beam computed tomography in a southern Chilean sub-population / Prevalencia de radix entomolaris en primeros molares mandibulares usando tomografía computarizada cone-beam en una subpoblación del sur de Chile

SUMMARY: The aim of this of this study was to evaluate the prevalence and morphology of radix entomolaris (RE) in the mandibular first molar (MFM) in a southern Chilean sub-population by cone-beam computed tomography (CBCT). Two hundred ten CBCT images of MFM were analysed. To detect the presence of RE, the observation and measurements were standardised, advancing 1 mm to apical from the floor of the pulp chamber to the most apical zone of the tooth. The data were analyzed using descriptive statistics, with a value of P < 0.05 being statistically significant. The prevalence of a third root in the permanent MFM was 5.7 % (12/210). The incidence of RE was the same in male patients (2.9 %) as in female patients (2.9 %) (p=0.324). The occurrence of an RE in the left MFM was 7.3 % (3/41 patients) for male patients and 4.5 % (3/66) for female patients (p=0.398). The right MFM in male patients had an incidence of 8.1 % (3/37) and 4.5 % (3/66) for female patients (p=0.340). When the presence of an RE was compared between the left (5.6 %) and right side (5.8 %), no statistically significant differences were found (p=0.998). The frequency of bilateral three-rooted MFM was 71.43 % (5/7) and 28.57 % (2/7) were unilateral. The prevalence of RE in MFM in a southern Chilean sub-population was 5.7 %. The occurrence was bilateral in the majority of cases and no significant differences were observed by sex or side. The commonest type of RE was Type 1 (83.3 %). The use of CBCT can improve the endodontic treatment outcome.

RESUMEN: El objetivo de este estudio fue evaluar la prevalencia y morfología de radix entomolaris (RE) en el primer mo- lar mandibular (MFM) en una subpoblación del sur de Chile mediante tomografía computarizada de haz cónico (CBCT). Se analizaron doscientas diez imágenes CBCT de MFM. Para detectar la presencia de OD se estandarizó la observación y las medidas, avanzando 1 mm apical desde el suelo de la cámara pulpar hasta la zona más apical del diente. Los datos fueron analizados mediante estadística descriptiva, siendo estadísticamente significativo un valor de P < 0,05. La prevalencia de una tercera raíz en el MFM permanente fue de 5,7 % (12/210). La incidencia de ER fue la misma en pacientes masculinos (2,9 %) que en pacientes femeninas (2,9 %) (p=0,324). La aparición de un ER en el MFM izquier- do fue del 7,3 % (3/41 pacientes) para los pacientes masculinos y del 4,5 % (3/66) para las pacientes femeninas (p=0,398). El MFM derecho en pacientes masculinos tuvo una incidencia de 8,1 % (3/ 37) y 4,5 % (3/66) para pacientes femeninos (p=0,340). Cuando se comparó la presencia de un OD entre el lado izquierdo (5,6 %) y derecho (5,8 %), no se encontraron diferencias estadísticamente significativas (p=0,998). La frecuencia de MFM de tres raíces bilaterales fue 71,43 % (5/7) y 28,57 % (2/7) fueron unilaterales. La prevalencia de RE en MFM en una subpoblación del sur de Chile fue de 5,7 %. La presentación fue bilateral en la mayoría de los casos y no se observaron diferencias significativas por sexo o lado. El tipo de ER más frecuente fue el tipo 1 (83,3 %). El uso de CBCT puede mejorar el resultado del tratamiento endodóntico.

Systematic Standardized and Individualized Assessment of Masticatory Cycles Using Electromagnetic 3D Articulography and Computer Scripts.

Masticatory movements are studied for decades in odontology; a better understanding of them could improve dental treatments. The aim of this study was to describe an innovative, accurate, and systematic method of analyzing masticatory cycles, generating comparable quantitative data. The masticatory cycles of 5 volunteers (Class I, 19 ± 1.7 years) without articular or dental occlusion problems were evaluated using 3D electromagnetic articulography supported by MATLAB software. The method allows the trajectory morphology of the set of chewing cycles to be analyzed from different views and angles. It was also possible to individualize the trajectory of each cycle providing accurate quantitative data, such as number of cycles, cycle areas in frontal view, and the ratio between each cycle area and the frontal mandibular border movement area. There was a moderate negative correlation (-0.61) between the area and the number of cycles: the greater the cycle area, the smaller the number of repetitions. Finally it was possible to evaluate the area of the cycles through time, which did not reveal a standardized behavior. The proposed method provided reproducible, intelligible, and accurate quantitative and graphical data, suggesting that it is promising and may be applied in different clinical situations and treatments.

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.

Characteristics of Chewing: An Update of the Literature

ABSTRACT: Chewing is the first step in the digestion process in mammals. It is a highly coordinated process with a complex sensorimotor activity, the aim of which is to prepare foods for the formation of the alimentary bolus and then swallowing. It is a process with defined stages and patterns of movement that adapt to changes derived from the environment or the individual. Here, we review the main characteristics of chewing, including aspects of the physiology and characteristics of the mechanics of mandibular movement. We highlight the latest advances reported and the new methodologies used for a chewing analysis, which has made it possible to collect more precise and reliable data. Thus, we will see how the new technologies have provided a better understanding of this function and its relation to aspects of an individual's general healt h such as nutrition or the appearance of neurodegenerative diseases. Also, in this review we emphasize the close relation that exists between chewing and a person's quality of life.

RESUMEN: La masticación es el primer paso en el proceso de digestión en los mamíferos, es un proceso altamente coordinado y con una compleja actividad sensoriomotora, cuyo objetivo es preparar los alimentos para la formación del bolo alimenticio y luego la deglución, es un proceso con etapas definidas y patrones de movimiento que se adaptan a los cambios derivados del entorno o del individuo, aquí se revisan las principales características de la masticación, incluyendo aspectos de la fisiología y características de la mecánica del movimiento mandibular, se destacan los últimos avances reportados y las nuevas metodologías utilizado para un análisis de la masticación, lo que ha permitido recolectar datos más precisos y confiables, así, veremos cómo las nuevas tecnologías han permitido comprender mejor esta función y su relación con aspectos de la salud general de un individuo como la nutrición o la aparición de enfermedades neurodegenerativas; además, en esta revisión destacamos la estrecha relación que existe entre la masticación y la calidad de vida.

Radiografía panorámica: una herramienta invaluable para el estudio del componente óseo y dental del territorio maxilofacial / Panoramic radiographs: an invaluable tool for the study of bone and teeth components in the maxillofacial region

RESUMEN: La radiografía panorámica es probablemente el examen de rutina más solicitado por los dentistas en el mundo. Entre sus ventajas están su bajo costo, rapidez y mayor seguridad debido a que los formatos digitales han permitido disminuir las dosis y tiempos de exposición a la radiación. Su potencial como herramienta diagnóstica radica en la posibilidad que tiene el clínico de observar el territorio maxilofacial casi en su totalidad, pudiendo realizar un estudio anatómico y morfológico acabado de diferentes regiones. En esta revisión se quiere ofrecer una mirada general de la amplia gama de usos que se le pueden dar a la radiografía panorámica, tanto en la clínica como en el ámbito de la investigación, destacando su potencial como herramienta de diagnóstico y su importancia para algunas áreas de especialidad en odontología.

SUMMARY: The panoramic radiograph is in all likelihood, the routine exam most required by dentists in the clinic worldwide. Among the advantages of using this type of radiograph, is that it is inexpensive, quick and also safer in digital format since it reduces the radiation dose and time of exposure. Its potential as a diagnostic tool is based on the possibility to explore almost all of the maxillofacial area, allowing a proper anatomic and morphological study of different areas at the same time. In this review, we aimed to provide an overview of the multiple uses of panoramic radiographs, highlighting its potential as a diagnostic tool and also its importance in some specialized areas of dentistry.

Radiopacity of alloplastic bone grafts measured with cone beam computed tomography: An analysis in rabbit calvaria.

Availability of adequate bone structure for dental implants is still a problem in dentistry. Alloplastic grafts, which promote bone regeneration, are used as bone substitutes in orthopedic and oral surgical procedures. The aim of this study was to evaluate the radiopacity of three different synthetic bone grafts in rabbit calvaria, over 3 months, using cone beam computed tomography (CBCT). Four critical-size defects were made on the calvaria of 11 rabbits. The lesions were classified into three groups according to the alloplastic grafts they received: Osteon® 70/30, Osteon collagen®, and Osteon II® groups. The fourth group received blood clot, and served as a control. The bone samples were collected and analyzed with CBCT after the 1st, 2nd, and 3rd month. One month after surgery, the lesions that received Osteon® 70/30 and Osteon collagen® grafts showed the highest radiopacity compared to the lesions with Osteon II® and blood clot. After the 2nd month, the radiopacity values between the three groups that received the grafts were more similar compared to the group with blood clot. After the 3rd month, the lesions with Osteon® 70/30 graft showed the highest radiopacity values, followed by Osteon collagen® and Osteon II® groups. The group that received blood clot showed the lowest radiopacity values. In conclusion, the grafts used in this study had higher radiopacity values compared to blood clot. Among the grafts used, the Osteon® 70/30 graft showed the highest radiopacity values in the 3-month period.

Análisis cinemático de la masticación de alimentos duros y blandos en participantes dentados utilizando articulografía electromagnética 3D / Kinematic analysis of hard and soft food mastication in dentate participants using 3D electromagnetic articulography

RESUMEN: Diversos estudios reportan que el tipo de alimento influye directamente en los patrones cinemáticos de la masticación. El objetivo de este estudio fue analizar y comparar los ciclos masticatorios de participantes adultos y completamente dentados durante la masticación de alimentos de diferente textura y dureza (maní y zanahoria) utilizando articulografía electromagnética 3D. Se evaluaron 11 participantes sanos (5 hombres; 6 mujeres), de 31,9 ± 5,2 años de edad. Mediante articulografía electromagnética 3D, se registró la masticación de dos alimentos de prueba (maní y zanahoria). Los datos de movimiento mandibular fueron procesados con MATLAB® y obteniendo diferentes parámetros-frecuencia masticatoria en ciclos por segundo, velocidad de descenso y ascenso mandibular, área de las proyecciones de cada ciclo masticatorio en los tres planos del espacio-que fueron comparados según tipo de alimento y género de los participantes. Se encontraron diferencias estadísticamente significativas entre las áreas de los ciclos masticatorios en el plano horizontal según tipo de alimento, siendo mayor para la masticación de zanahoria (P=,003). Así mismo, se detectaron diferencias estadísticamente significativas entre las áreas sagitales de los ciclos entre hombres y mujeres, siendo mayor en mujeres (P=,042). Nuestros resultados concuerdan con otros estudios que afirman que la textura del alimento influye en las características cinemáticas de los ciclos masticatorios.

SUMMARY: Several studies report that the type of food directly influences the kinematic patterns of mastication. The aim of this study was to analyze and compare the chewing cycles of adult and fully dentate participants during the mastication of foods of different texture and hardness (peanuts and carrots) using 3D electromagnetic articulography. Eleven healthy participants (5 men; 6 women), 31.9 ± 5.2 years old, were evaluated. By means of 3D electromagnetic articulography, the mastication of two test foods (peanuts and carrots) was recorded. The data associated to mandibular movement were processed with MATLAB® obtaining different parameters-masticatory frequency in cycles per second, mandibular descent and ascent rate, area of the projections of each masticatory cycle in the three planes of space-which were compared according to type of food and sex of the participants. Statistically significant differences were found between the areas of the masticatory cycles in the horizontal plane according to type of food, being greater for carrots (P=.003). Likewise, statistically significant differences were detected between the sagittal areas of the cycles between men and women, being greater in women (P=.042). Our results agree with other studies that affirm that the texture of the food influences the kinematic characteristics of the masticatory cycles.

Hallazgo radiográfico de cuerpo extraño en piso de seno maxilar de sujeto asintomático / Radiographic finding of a foreign body in the maxillary sinus floor of an asymptomatic subject

El seno maxilar (SM) es una cavidad par presente en el hueso maxilar, que puede presentar diversas alteraciones o lesiones patológicas factibles de ser pesquisadas mediante estudios imagenológicos. En este sentido, la opacidad, el ocupamiento y/o engrosamiento de las mucosas son los signos orientadores para el diagnóstico de patologías en estas estructuras, las que pueden ir desde sinusitis, hasta antrolitos, pasando por hipoplasias, pseudoquistes u osteomas. En el siguiente reporte presentamos el caso de una mujer de 75 años de edad en la cual mediante examinación radiográfica de rutina se observa un cuerpo extraño en el SM derecho en relación a diente 1.6. De acuerdo a esto, se solicitó una tomografía computarizada cone-beam (CBCT) para evaluar posibles implicancias con tratamiento dental rehabilitador. Al examen se observan dos estructuras de alta densidad (densidad metálica), redondeadas, una al lado de la otra, en contacto inmediato a la cortical sinusal sin comprometerla. También se observa una cortical sinusal conservada en todo su recorrido y discreto engrosamiento mucoso en relación a dichas estructuras. En consideración con los antecedentes de la paciente, se opta por un manejo conservador del hallazgo mediante controles periódicos. Se propone la hipótesis de la formación de un antrolito de origen exógeno, que se corresponde con el historial de tratamiento endodóntico en la zona. El diagnóstico diferencial de los hallazgos radiográficos encontrados es fundamental para establecer los lineamientos terapéuticos de nuestros pacientes, por ello es importante contar con personal clínico capacitado para la interpretación de las imágenes.

The maxillary sinus (SM) is an even cavity present in the maxillary bone, which may present a number of pathological alterations or lesions that can be investigated through imaging analysis. In this sense, opacity, location and / or thickening of the mucous membranes are guides for the diagnosis of pathologies in these structures. These can range from sinusitis, to antrolites, to hypoplasias, pseudocysts or osteomas. In this study the case of a 75-year-old woman is presented. During routine radiographic examination, a foreign body was observed in the right MS in relation to tooth 1.6. A cone-beam computed tomography (CBCT) was requested to evaluate possible rehabilitative dental treatment. Upon examination, two highdensity rounded structures (metal density) adjacent to each other were noted. The structures were in direct contact with the sinus cortex without compromising it. Furthermore in relation to the above structures, scant cortical sinus was observed throughout its course, as well as slight mucous thickening. Considering the patient's background, it was determined to use conservative treatment through periodic controls. Hypothesis of an exogenous mass is proposed, corresponding to the history of endodontic treatment in the area. In view of the differential diagnosis of radiographic findings found, it is essential to implement therapeutic guidelines for patients and have trained clinical staff available to interpret the images.

Description of acoustic and articulatory parameters of vowels in mapudungun speakers: pilot study / Descripción de parámetros acusticos y articulatorios de las vocales en hablantes de mapudungun: estudio piloto

Mapudungun is a language used by Mapuche people in some regions of Chile and Argentina. The aim of this study was to describe the vowel phonemes with regard to the articulatory parameters (position of the tongue with respect to the palate and jaw opening) and acoustic parameters (f0, F1, F2 and F3) in Mapudungun speakers in the Region of La Araucanía. The vocalic phonemes of Mapudungun are six, where the first five are similar to those used in Spanish (/a e i o u/), to which is added a sixth vowel (/ɨ/) with its vocalic allophones (/ɨ/) and [Ә]. Three Mapudungun speakers were evaluated. The tongue movements were collected by Electromagnetic Articulography 3D and the data were processed with MATLAB and PRAAT software. It was possible to describe the trajectory of each third of the tongue during the production of the vowels. It was observed that the sixth vowel /Ә/ had minimal jaw opening during its pronunciation. In addition, the characteristic of /Ә/ as an unrounded mid-central vowel was corroborated. In this study, the tongue of mapudungun speakers was in a more posterior position than the found in other studies.

El Mapudungun es un lenguaje utilizado por los mapuches en algunas regiones de Chile y Argentina. El objetivo de este estudio fue describir los fonemas vocálicos respecto a los parámetros articulatorios (posición de la lengua respecto al paladar y apertura mandibular) y los parámetros acústicos (f0, F1, F2 y F3) en hablantes de Mapudungun en la Región de La Araucanía, los fonemas vocálicos de Mapudungun son seis, donde los primeros cinco son similares a los utilizados en español (/a e i o u /), a los que se agrega una sexta vocal (/ɨ/) con sus alófonos vocálicos [ɨ] y [Ә]. Se evaluaron tres hablantes de Mapudungun. Los movimientos de la lengua fueron registrados por Articulografía Electromagnética 3D y los datos fueron procesados con el software MATLAB y PRAAT. Fue posible describir la trayectoria de cada tercio de la lengua durante la producción de las vocales. Se observó que la sexta vocal /Ә/ tenía una apertura mínima de la mandíbula durante su pronunciación. Además, se corroboró la característica de /Ә/ como vocal central media no redondeada. En este estudio, la lengua de los hablantes de mapudungun estaba en una posición más posterior que la encontrada en otros estudios.

Characteristics of Mandibular Movement and Mastication in Older Adults with Removable Dental Prostheses: Three-Dimensional Analysis / Características de Movimientos Mandibulares y Masticación en Adultos Mayores con Prótesis Dental Removible: un Análisis Tridimensional

ABSTRACT: 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.

RESUMEN: El envejecimiento es un proceso dinámico que incluye varias alteraciones en la cavidad oral, siendo la pérdida de dientes la más frecuente. El tratamiento de rehabilitación puede incluir prótesis fijas o removibles y/o implantes. El objetivo de este estudio fue describir las características geométricas (trayectoria, rangos, áreas) y cinemáticas (velocidad) de los movimientos mandibulares y masticatorios en participantes con prótesis dentales realizando un análisis en tres dimensiones. Se consideró una muestra de 10 participantes con rehabilitación protésica y se dividió en tres grupos (prótesis total, atípica e implantosoportada), se midieron las características de los movimientos mandibulares bordeantes y masticatorios con articulografía electromagnética 3D. Se obtuvo el polígono Posselt en los planos frontal y sagital, se analizaron sus áreas, trayectorias y rangos. Se analizaron los movimientos masticatorios en cuanto al área de cada ciclo, la frecuencia, la velocidad y la razón entre el área el ciclo masticatorio y los movimientos bordeantes, sin diferencias significativas entre los grupos. Los sujetos con prótesis dentales, independientemente del tipo, mostraron disminución de movimiento (bordeante y funcional) en comparación con los sujetos dentados sin alteraciones funcionales cuyos valores se han informado en la literatura. Los sujetos con prótesis implantosoportada tienen valores más cercanos a lo que se describe para sujetos jóvenes dentados.