Tratamiento del tumor odontogénico queratoquístico: revisión sistemática / Surgical treatment of odontogenic keratocystic tumor: a systematic review

Introducción: El queratoquiste odontogénico (QO) se considera hoy en día un tumor odontogénico benigno. A pesar de esto, tiene un carácter agresivo debido fundamentalmente a su potencial expansivo a nivel local y a su alta capacidad de recidiva. Actualmente, existen diferentes variedades terapéuticas que se relacionan directamente con las tasas de recurrencia de este tipo de tumor. Objetivo: El objetivo de este estudio es analizar las tasas de recurrencia de las diferentes modalidades de tratamiento del QO. Material y método: Siguiendo las recomendaciones PRISMA se realizó una revisión sistemática en diferentes bases de datos analizando las tasas de recurrencia de distintas opciones terapéuticas del QO. Resultados: El porcentaje medio de recurrencia de los 11 artículos revisados fue del 26,8 %, siendo la resección en bloque el tratamiento con menores tasas de recidiva (0 %) y la marsupialización el tratamiento que mayor porcentaje de recurrencia presentó (45,8 %). Discusión: La recidiva se relaciona directamente con la posibilidad de que restos del tumor o del epitelio que lo rodea puedan permanecer en la cavidad después del tratamiento. Por ello, la resección en bloque es el tratamiento que menos recurrencia presenta. Sin embargo, la agresividad de esta modalidad terapéutica no está justificada en todos los casos, existiendo otras variantes muy eficaces como la enucleación, ya sea sola o en combinación con terapias coadyuvantes como la aplicación de solución de Carnoy. Conclusiones: El tratamiento resectivo presenta las menores tasas de recurrencia, aunque se considera que el QO puede ser abordado de una manera más conservadora dada su naturaleza benigna

Introduction: The odontogenic keratocystic (OK) is considered nowadays as a benign odontogenic tumor. Nevertheless, it has an aggressive nature due mainly to its local expansive potential and its high recurrence rate. Currently, there are different therapeutic approaches that are directly related to the recurrence rates of this type of tumor. Objective: The objective of this study is to analyze the recurrence rates of the different treatment modalities of the OK. Material and method: Following PRISMA recommendations, it was perfomed a systematic review in different databases analyzing the recurrence rates of different therapeutic options of the OK. Results: The average percentage of recurrence of the 11 articles reviewed was of 26,8 %, being resection the treatment with lower recurrence rates (0 %) and marsupialization the treatment with the highest percentage of recurrence (45,8 %). Discussion: Recurrence is directly related to the possibility that parts of the epithelium may remain in the cavity after treatment. Therefore, resection is the treatment with the least recurrence. However, the aggressiveness of this therapeutic modality is not justified in all cases. There are other very effective variants such as enucleation either alone or in combination with adjuvant therapies such as Carnoy's solution application. Conclusions: Resective treatment has the lowest recurrence rates although it is considered that the OK can be approached in a more conservative way due to its benign nature

Effect of physicochemical properties of a cement based on silicocarnotite/calcium silicate on in vitro cell adhesion and in vivo cement degradation.

A silicon calcium phosphate cement (Si-CPC) was developed to produce a composite of calcium phosphate and calcium silicate. The silicon cements prepared with low silicon (Si) content were composed of crystalline phases of brushite and silicocarnotite. However, the cements prepared with high Si content were mainly composed of amorphous phases of silicocarnotite, hydroxyapatite and calcium silicate. The cement porosity was about 40% with a shift of the average pore diameter to the nanometric range with increasing Si content. Interestingly, this new cement system provides a matrix with a high specific surface area of up to 29 m(2) g(-1). The cytocompatibility of the new Si-doped cements was tested with a human osteoblast-like cell line (MG-63) showing an enhancement of cell proliferation (up to threefold) when compared with unsubstituted material. Cements with a high silica content also improved the cell attachment. The in vivo results indicated that Si-CPCs induce the formation of new bone tissue, and modify cement resorption. We conclude that this cement provides an optimal environment to enhance osteoblast growth and proliferation that could be of interest in bone engineering.

Magnesium substitution in brushite cements.

The use of magnesium-doped ceramics has been described to modify brushite cements and improve their biological behavior. However, few studies have analyzed the efficiency of this approach to induce magnesium substitution in brushite crystals. Mg-doped ceramics composed of Mg-substituted ß-TCP, stanfieldite and/or farringtonite were reacted with primary monocalcium phosphate (MCP) in the presence of water. The cement setting reaction has resulted in the formation of brushite and newberyite within the cement matrix. Interestingly, the combination of SAED and EDX analyses of single crystal has indicated the occurrence of magnesium substitution within brushite crystals. Moreover, the effect of magnesium ions on the structure, and mechanical and setting properties of the new cements was characterized as well as the release of Ca(2+) and Mg(2+) ions. Further research would enhance the efficiency of the system to incorporate larger amounts of magnesium ions within brushite crystals.

Effect of silica gel on the cohesion, properties and biological performance of brushite cement.

The cohesion of calcium phosphate cements can be improved by the addition of substances to either the solid or liquid phase during the setting reaction. This study reports the effect of silica gel on brushite cement cohesion. The cement was prepared using a mixture of beta-tricalcium phosphate (beta-TCP) and monocalcium phosphate monohydrate as the solid phase, while the liquid phase comprised carboxylic acids silica gel. This cement presents a shorter final setting time (FST), better cohesion and higher amount of unreacted beta-TCP than the cement prepared without silica gel. Furthermore, in vivo experiments using rabbits as an animal model showed that after 8 weeks of implantation cements modified with silica gel showed a similar new bone formation volume and more remaining graft in comparison with unmodified cements. Thus, the silica gel could be efficiently applied to reduce cement disintegration and to decrease the resorption rate of brushite cements.

A comparative study of 2 methods for obtaining platelet-rich plasma.

PURPOSE: Double and single centrifugation are the most commonly used techniques for obtaining platelet-rich plasma (PRP) in dentistry. In this study, we used and compared 2 methods for obtaining PRP: double centrifugation (ACE system; Surgical Supply and Surgical Science Systems, Brockton, MA) and single centrifugation (Nahita system; Nahita, Navarra, Spain). MATERIALS AND METHODS: Blood samples were obtained from 30 random patients. Each blood sample was treated using the ACE system and Nahita system methods, after which the obtained material was analyzed by flow cytometry for platelet counts and by transmission electron microscopy (TEM) for ultrastructural analysis of the PRP gel. RESULTS: Platelet count analysis of the PRP obtained from both methods revealed that the ACE and Nahita systems accomplished platelet concentrations of (336%) and (227%), respectively. The platelet counting results obtained from the ACE system samples were more dispersed than their Nahita system counterpart. The ultrastructural (ie, TEM) study showed considerable alterations of the platelet aggregates in the ACE's PRP, especially when the samples were not mixed in the final stage of the procedure, whereas the Nahita aggregates always had a normal physiological appearance. CONCLUSIONS: The ACE double-centrifugation method is able to achieve higher platelet concentrations than the single-centrifugation Nahita system, although the results obtained by ACE were more dispersed. Nevertheless, the ACE system provoked alterations in the PRP ultrastructure, and it was more sensitive to small errors during preparation.

Bases fisiológicas de la regeneración ósea II. El proceso de remodelado / Physiological bases of bone regeneration II. The remodeling process

El remodelado óseo es un proceso de reestructuración del hueso existente, que está en constante formación y reabsorción. Este fenómeno equilibrado permite, en condiciones normales, la renovación de un 5-10% del hueso total al año. A nivel microscópico el remodelado óseo se produce en las unidades básicas multicelulares, donde los osteoclastos reabsorben una cantidad determinada de hueso y los osteoblastos forman la matriz osteoide y la mineralizan para rellenar la cavidad previamente creada. En estas unidades hay osteoclastos, macrófagos, preosteoblastos y osteoblastos y están regidos por una serie de factores, tanto generales como locales, permitiendo el normal funcionamiento del hueso y el mantenimiento de la masa ósea. Cuando este proceso se desequilibra aparece la patología ósea, bien por exceso (osteopetrosis) o por defecto (osteoporosis). El propósito de este trabajo es realizar una revisión de los conocimientos actuales sobre los mecanismos bioquímicos y fisiológicos del proceso de remodelado óseo, resaltando de manera especial el papel de los factores reguladores del mismo, entre los que destacan los factores de crecimiento

Bone remodeling is the restructuring process of existing bone, which is in constant resorption and formation. Under normal conditions, this balanced process allows the renewal of 5 – 10% of bone volume per year. At the microscopic level, bone remodeling is produced in basic multicellular units, where osteoclasts resorb a certain quantity of bone and osteoblasts form the osteoid matrix and mineralize it to fill the previously created cavity. These units contain osteoclasts, macrophages, preosteoblasts and osteoblasts, and are controlled by a series of factors, both general and local, allowing normal bone function and maintaining the bone mass. When this process becomes unbalanced then bone pathology appears, either in excess (osteopetrosis) or deficit (osteoporosis). The purpose of this study is to undertake a revision of current knowledge on the physiological and biological mechanisms of the bone remodeling process; highlighting the role played by the regulating factors, in particular that of the growth factors

Physiological bases of bone regeneration II. The remodeling process.

Bone remodeling is the restructuring process of existing bone, which is in constant resorption and formation. Under normal conditions, this balanced process allows the renewal of 5-10% of bone volume per year. At the microscopic level, bone remodeling is produced in basic multicellular units, where osteoclasts resorb a certain quantity of bone and osteoblasts form the osteoid matrix and mineralize it to fill the previously created cavity. These units contain osteoclasts, macrophages, preosteoblasts and osteoblasts, and are controlled by a series of factors, both general and local, allowing normal bone function and maintaining the bone mass. When this process becomes unbalanced then bone pathology appears, either in excess (osteopetrosis) or deficit (osteoporosis). The purpose of this study is to undertake a revision of current knowledge on the physiological and biological mechanisms of the bone remodeling process; highlighting the role played by the regulating factors, in particular that of the growth factors.

Physiological bases of bone regeneration I. Histology and physiology of bone tissue.

Bone is the only body tissue capable of regeneration, allowing the restitutio ad integrum following trauma. In the event of a fracture or bone graft, new bone is formed, which following the remodeling process is identical to the pre-existing. Bone is a dynamic tissue in constant formation and resorption. This balanced phenomena, known as the remodeling process, allows the renovation of 5-15% of the total bone mass per year under normal conditions. Bone remodeling consists of the resorption of a certain amount of bone by osteoclasts, likewise the formation of osteoid matrix by osteoblasts, and its subsequent mineralization. This phenomenon occurs in small areas of the cortical bone or the trabecular surface, called Basic Multicellular Units (BMU). Treatment in Traumatology, Orthopedics, Implantology, and Maxillofacial and Oral Surgery, is based on the biologic principals of bone regeneration, in which cells, extracellular matrix, and osteoinductive signals are involved. The aim of this paper is to provide an up date on current knowledge on the biochemical and physiological mechanisms of bone regeneration, paying particular attention to the role played by the cells and proteins of the bone matrix.

Bases fisiológicas de la regeneración ósea I. Histología y fisiología del tejido óseo / Physiological bases of bone regeneration I. Histology and physiology of bone tissue

El hueso es el único tejido del organismo capaz de regenerarse, permitiendo la restitutio ad integrum tras el trauma. Cuando se produce una fractura, se coloca un implante osteointegrado o se realiza un injerto para aumentar el sustrato óseo antes de la inserción de implantes, lo que se pretende es la regeneración ósea, es decir, la formación de hueso nuevo que, tras un proceso de remodelado, sea idéntico al preexistente.El hueso es un tejido dinámico en constante formación y reabsorción. Este fenómeno equilibrado, denominado proceso de remodelado, permite la renovación de un 5-15 % del hueso total al año en condiciones normales (1). El remodelado óseo consisteen la reabsorción de una cantidad determinada de hueso llevada a cabo por los osteoclastos, así como la formación de la matriz osteoide por los osteoblastos y su posterior mineralización. Este fenómeno tiene lugar en pequeñas áreas de la cortical o de la superficie trabecular, llamadas “unidades básicas de remodelado óseo”.La actuación terapéutica en los campos de la Traumatología y Ortopedia, Cirugía Oral y Maxilofacial e Implantología, se asienta sobre los principios biológicos de la regeneración ósea, en los que están implicados células, matriz extracelular y señales osteoinductivas. El objetivo de este trabajo es realizar una puesta al día de los conocimientos actuales sobre los mecanismos bioquímicos y fisiológicos de la regeneración ósea, resaltando de manera especial el papel que en ella juegan las células y las proteínas de la matriz ósea

Bone is the only body tissue capable of regeneration, allowing the restitutio ad integrum following trauma. In the event of a fracture or bone graft, new bone is formed, which following the remodeling process is identical to the pre-existing.Bone is a dynamic tissue in constant formation and resorption. This balanced phenomena, known as the remodeling process, allows the renovation of 5-15% of the total bone mass per year under normal conditions (1). Bone remodeling consists of the resorption of a certain amount of bone by osteoclasts, likewise the formation of osteoid matrix by osteoblasts, and its subsequentmineralization. This phenomenon occurs in small areas of the cortical bone or the trabecular surface, called “Basic Multicellular Units” (BMU). Treatment in Traumatology, Orthopedics, Implantology, and Maxillofacial and Oral Surgery, is based on the biologic principals of bone regeneration, in which cells, extracellular matrix, and osteoinductive signals are involved.The aim of this paper is to provide an up date on current knowledge on the biochemical and physiological mechanisms of bone regeneration, paying particular attention to the role played by the cells and proteins of the bone matrix

[Cystic disease of the biliary tract. Three decades of institutional experence]. / Enfermedad quística de la vía biliar en el adulto. Tres décadas de experiencia institucional.

INTRODUCTION: Cystic disease of biliary tract (CDBT) characterizes by the presence of sacular expansions of the biliary tree. It is an uncommon disease associated with high morbidity and malignant transformation. More than 60% of patients are women and can be diagnosed in the adult life. OBJECTIVE: To evaluate the results obtained during last three decades in the management of CDBT in the adult patient. PATIENTS AND METHODS: All the patients with CDBT treated from 1970 to 2002 were included. Demographic data, clinical picture, boarding diagnosis, classification, treatment, evolution and survival were analyzed. RESULTS: 34 patients. Twenty eight (82%) women and 6 (18%) men with a mean age of 33 years (range 13-84). The most frequent symptoms were abdominal pain, nausea-vomit and jaundice. Cholangiography was made in all cases. All the types described by Todani were documented. Twenty-seven patients (80%) were surgically treated. The mean follow-up was 84 months (range 1-408 months). Fifteen patients (44.1%) were readmitted and 9 (26.4%) had a reoperation. Three (9%) died with malignant transformation. The global survival was 91.1% to 12 months. CONCLUSIONS: In the adult patient, diagnosis of CDBT requires a high level of suspicion and its confirmation depends on the image studies. The CDBT diagnosis considers an indication of surgical treatment. Complete resection of the biliary tract with Roux en-Y hepato-jejunal anastomosis have less rate of mechanical complications, hospitalary readmissions and surgical reintervention.