Search

Purpose To validate the finding of an association between single nucleotide polymorphisms (SNPs) and toxicity during chemoradiotherapy (CRT) in rectal cancer patients, in an independent population. Methods and Materials The cohort consisted of 165 patients who received CRT for rectal cancer from 2006 to 2012. Prospectively recorded toxicity information, graded according to the Common Terminology Criteria for Adverse Events version 3.0, was retrieved from the medical record. Additionally, a subset of 52 patients recorded their gastrointestinal symptoms weekly during CRT, using the 7-item Bowel Problems Scale. Deoxyribonucleic acid was extracted from normal tissue in the proctectomy specimens and screened for 3 SNPs: XRCC1 R399Q, XPD K751Q, and TGFβ1 R25P. Univariable and multivariable logistic regression models were constructed. Results The median radiation dose was 50.4 Gy, and all patients received concurrent chemotherapy. Toxicities measured by the Common Terminology Criteria for Adverse Events were closely associated with patient-reported outcomes for the patients who completed the 7-item Bowel Problems Scale. Grade ≥3 toxicity occurred during CRT in 14 patients (8%). All 14 patients had either XRCC1 R399Q or TGFβ1 R25P polymorphisms. The TGFβ1 R25P polymorphism was significantly associated with grade ≥3 toxicity (odds ratio [OR] 3.47, P =.04) and, in patients who completed the Bowel Problems Scale, with grade ≥4 toxicity (OR 5.61, P =.02). The latter finding persisted in a multivariable logistic regression model controlling for ethnicity, age, and sex (adjusted OR 1.83, P =.02). Conclusions We have validated the correlation between the TGFβ1 R25P SNP and acute toxicity during CRT in an independent cohort using both clinician- and patient-reported toxicity. The information from our study could be used as a basis to formulate a prospective trial testing the utility of this SNP as a biomarker of acute toxicity during neoadjuvant treatment in locally advanced rectal cancer.

Introducción: la estabilidad es uno de los principales objetivos del tratamiento de ortodoncia, y la fibrotomía supracrestal circunferencial es una de las alternativas para prevenir la recidiva en casos de rotaciones dentales, apiñamiento y dientes con inclinación; sin embargo, no se tienen estudios que demuestren la efectividad de este tratamiento, así como sus efectos en la condición periodontal. El objetivo de esta revisión sistemática (RS) consistió en evaluar la efectividad de la fibrotomía supracrestal circunferencial (FSC) como procedimiento coadyuvante en la estabilidad del tratamiento de ortodoncia durante la retención, así como los efectos en la condición periodontal posterior a su realización. Métodos: la búsqueda de estudios relacionados con el tema se realizó mediante las bases de datos PubMed y EMBASE hasta octubre de 2018. Los estudios fueron considerados elegibles si abarcaban el uso de la FSC durante el periodo de retención y si reportaban la condición periodontal con un tiempo de seguimiento mayor o igual a un año. Para la evaluación del riesgo de sesgos en los estudios elegidos, se aplicó la escala Newcastle-Ottawa en los estudios observacionales y la herramienta de colaboración Cochrane para los ensayos clínicos aleatorizados (ECA) y ensayos clínicos controlados (ECC). Resultados: la estrategia de búsqueda arrojó 85 posibles artículos elegibles, de los cuales 5 fueron incluidos en laRS. Cuatro de los cinco estudios reportaron un índice de irregularidad menor en los pacientes que tuvieron FSC cuando se compararon con un grupo control. Con respecto a la condición periodontal, no se reportaron cambios en índice de placa, índice gingival, niveles de inserción, profundidad al sondaje y cantidad de encía queratinizada. Conclusiones: la fibrotomía es un método eficaz para evitar la recidiva de dientes previamente rotados y no genera alteraciones a nivel periodontal. Sin embargo, es importante tener en cuenta que la calidad metodológica de los estudios no fue alta.

Introduction: stability is one of the main goals of orthodontic treatment, and circumferential supracrestal fiberotomy is an alternative to prevent relapse in cases of tooth rotation, crowding and inclined teeth. However, there are no studies demonstrating the effectiveness of this treatment and its effects on the periodontal condition. The aim of this systematic review (SR) was to evaluate the effectiveness of circumferential supracrestal fiberotomy (CSF) as an adjuvant in the stability of orthodontic treatment during retention and its effects on the periodontal condition once it has been performed. Methods: the search for topic-related studies was conducted on the PubMed and EMBASE databases until October 2018. The studies were considered eligible if they covered the use of CSF during the retention period and reported the periodontal condition in a follow-up period longer than or equal to 1 year. For bias-risk assessment in the chosen studies, the Newcastle-Ottawa Scale was applied to observational studies, and the Cochrane Collaboration tool for Randomized Clinical Trials (RCTs) and Controlled Clinical Trials (CCTs). Results: the search strategy yielded 85 potential eligible articles, of which 5 were included in the SR. Four of the five studies reported a lower irregularity rate in patients who had CSF when compared to a control group. No changes in plaque index, gingival index, insertion levels, probe depth and keratinized gingiva amount were reported. Conclusions: fiberotomy is an effective method to prevent relapse of previously rotated teeth and does not cause periodontal alterations. However, it is important to note that the studies’ methodological quality was low. RESUMEN Introducción: la estabilidad es uno de los principales objetivos del tratamiento de ortodoncia, y la fibrotomía supracrestal circunferencial es una de las alternativas para prevenir la recidiva en casos de rotaciones dentales, apiñamiento y dientes con inclinación; sin embargo, no se tienen estudios que demuestren la efectividad de este tratamiento, así como sus efectos en la condición periodontal. El objetivo de esta revisión sistemática (RS) consistió en evaluar la efectividad de la fibrotomía supracrestal circunferencial (FSC) como procedimiento coadyuvante en la estabilidad del tratamiento de ortodoncia durante la retención, así como los efectos en la condición periodontal posterior a su realización. Métodos: la búsqueda de estudios relacionados con el tema se realizó mediante las bases de datos PubMed y EMBASE hasta octubre de 2018. Los estudios fueron considerados elegibles si abarcaban el uso de la FSC durante el periodo de retención y si reportaban la condición periodontal con un tiempo de seguimiento mayor o igual a un año. Para la evaluación del riesgo de sesgos en los estudios elegidos, se aplicó la escala Newcastle-Ottawa en los estudios observacionales y la herramienta de colaboración Cochrane para los ensayos clínicos aleatorizados (ECA) y ensayos clínicos controlados (ECC). Resultados: la estrategia de búsqueda arrojó 85 posibles artículos elegibles, de los cuales 5 fueron incluidos en la RS. Cuatro de los cinco estudios reportaron un índice de irregularidad menor en los pacientes que tuvieron FSC cuando se compararon con un grupo control. Con respecto a la condición periodontal, no se reportaron cambios en índice de placa, índice gingival, niveles de inserción, profundidad al sondaje y cantidad de encía queratinizada. Conclusiones: la fibrotomía es un método eficaz para evitar la recidiva de dientes previamente rotados y no genera alteraciones a nivel periodontal. Sin embargo, es importante tener en cuenta que la calidad metodológica de los estudios no fue alta.

Innovation ecosystems and emerging technologies can potentially accelerate the access to safe, affordable surgical care in low-resource settings. There is a need to develop localised innovation ecosystems that can establish an initial culture and catalyse the creation, adoption and diffusion of innovation. The surgathon model outlines one approach to seeding surgical innovation ecosystems. International academic institutions collaborated on six global surgery, innovation and ethics-themed hackathons (‘surgathons’) across India and Rwanda between 2016 and 2019. Over 1598 local multidisciplinary students participated, learning about challenges in the delivery of surgical care and ideating solutions that could leverage appropriate technology and resources for impact. Pursuing student ideas and evaluating their implementation past the surgathons continues to be an active effort. Surgathons have unfolded in different permutations based on local faculty, institution and health system context. The surgathon model is a novel method of priority setting challenges in global surgery and utilises locally driven expertise and innovation capacity to derive ethical solutions. The model offers a path for low-resource setting students and faculty to learn, advocate and innovate for improved surgical care.

Objectives Recommendations for polysomnography (PSG) in pediatric sleep disordered breathing (SDB) vary between the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) and the American Academy of Pediatrics (AAP). We determined the rates of preoperative PSG in children without risk factors outlined in the AAO-HNS Clinical Practice Guidelines and described the postoperative course of those patients following T&A. Methods Patients aged 3–17 undergoing T&A for SDB or OSA who did not have an indication for preoperative PSG were included. We conducted retrospective review to describe the rate, type, and timing of respiratory complications for patients with and without PSG following T&A, and discuss cases where disposition was changed due to PSG results. Results 1135 patients without risk factors underwent T&A for SDB or OSA. 196 (17%) had a preoperative PSG, of whom 85 (43.3%) had AHI >10 and 38 (24.8%) had an O2 nadir Conclusion PSG in children without risk factors results in admission of otherwise healthy patients following T&A who would have otherwise undergone ambulatory surgery. PSG alone in pediatric patients with no AAO-HNS risk factors should not influence postoperative disposition. These patients should be monitored for 3 h post-T&A and discharged in the absence of complications. Evidence level 2b

Rectal cancer (RC) is a challenging disease to treat that requires chemotherapy, radiation, and surgery to optimize outcomes for individual patients. No accurate model of RC exists to answer fundamental research questions relevant to patients. We established a biorepository of 65 patient-derived RC organoid cultures (tumoroids) from patients with primary, metastatic, or recurrent disease. RC tumoroids retained molecular features of the tumors from which they were derived, and their ex vivo responses to clinically relevant chemotherapy and radiation treatment correlated with the clinical responses noted in individual patients’ tumors. Upon engraftment into murine rectal mucosa, human RC tumoroids gave rise to invasive RC followed by metastasis to lung and liver. Importantly, engrafted tumors displayed the heterogenous sensitivity to chemotherapy observed clinically. Thus, the biology and drug sensitivity of RC clinical isolates can be efficiently interrogated using an organoid-based, ex vivo platform coupled with in vivo endoluminal propagation in animals.

Rectal cancer (RC) is a challenging disease to treat that requires chemotherapy, radiation, and surgery to optimize outcomes for individual patients. No accurate model of RC exists to answer fundamental research questions relevant to individual patients. We established a biorepository of 32 patient-derived RC organoid cultures (tumoroids) from patients with primary, metastatic, or recurrent disease. RC tumoroids retained molecular features of the tumors from which they were derived, and theirex vivoresponses to clinically relevant chemotherapy and radiation treatment correlate well with responses noted in individual patients’ tumors. Upon engraftment into murine rectal mucosa, human RC tumoroids gave rise to invasive rectal cancer followed by metastasis to lung and liver. Importantly, engrafted tumors closely reflected the heterogenous sensitivity to chemotherapy observed clinically. Thus, the biology and drug sensitivity of RC clinical isolates can be efficiently interrogated using an organoid-based,in vitroplatform coupled with endoluminal propagation in animals.

Introduction: the objective of this study was to evaluate the periodontal effects of fixed retainers in the long term. Methods: a search in electronic databases (PubMed, Cochrane Library, Science Direct, Embase, ProQuest, Ebsco, Biomed Central, Medline, Lilacs, and Google Scholar) and a manual search with no language restrictions. The inclusion criteria were: randomized clinical trials and meta-analysis, prospective and retrospective studies, studies in humans, clinical and radiographical studies evaluating the periodontium, performed during the 1987-2014 period, up to 10 years of follow-up. Four authors extracted data from the selected studies independently. Results: after applying the inclusion criteria, we selected 4 studies in which a total of 405 patients were evaluated. All the studies were longitudinal and retrospective. There was a greater prevalence of gingival recessions, especially in mandibular incisors, which are more vulnerable. There were no significant changes in terms of alveolar bone index or calculus index. The survival rate of fixed retainers was 50% or higher. Due to the heterogeneity of the selected studies, including difference in study population, differences in methods to assess the intervention, and follow-up periods, it was impossible to quantify the variables to perform a meta-analysis. Conclusions: the selected studies had a middle level of evidence. The greatest gingival recessions occurred with the use of fixed retainers in a long time; however, there is no alteration of the alveolar bone level. The studies recommend encouraging patients to maintain good oral hygiene. The findings of this review should be cautiously taken due to the resulting level of evidence, and the general recommendation for clinicians is that, in the long run, these retainers appear to be safe to maintain the alignment of mandibular incisors, although more studies with greater scientific rigor are required. There were no conflicts of interest and this study did not have any kind of financial support. RESUMEN. Introducción: el objetivo del presente estudio consistió en evaluar los efectos periodontales de los retenedores fijos a largo plazo. Métodos: se realizó una búsqueda en bases de datos electrónicas (PubMed, Cochrane Library, Science Direct, Embase, ProQuest, Ebsco, Biomed Central, Medline, Lilacs y Google Scholar) y una búsqueda manual sin restricción de lenguaje. Los criterios de inclusión fueron: ensayos clínicos aleatorizados y metaanálisis, estudios prospectivos y retrospectivos, estudios en humanos, estudios en los que se evaluara clínica y radiográficamente el periodonto, periodo comprendido entre 1987 y 2014, seguimiento hasta 10 años. Cuatro autores extrajeron independientemente los datos de los estudios seleccionados. Resultados: después de aplicar los criterios de inclusión, se seleccionaron 4 estudios en los que se evaluaron un total de 405 pacientes. Todos los estudios fueron longitudinales retrospectivos. Se encontró una mayor prevalencia de recesiones gingivales, especialmente de los incisivos mandibulares, que son más vulnerables. No mostraron cambios significativos ni el índice de hueso alveolar ni el índice de cálculo. La tasa de supervivencia de los retenedores fijos fue mayor del 50%. Debido a la heterogeneidad de los estudios seleccionados, entre los cuales se encuentra la diferencia en la población de estudio, diferencias en los métodos para evaluar la intervención y el tiempo de seguimiento, fue imposible cuantificar las variables para realizar un metaanálisis. Conclusiones: los estudios seleccionados tuvieron un nivel de evidencia medio. Se presentan mayores recesiones gingivales con el uso de los retenedores fijos a largo plazo; sin embargo, no hay alteración del nivel óseo alveolar. Los estudios recomiendan incentivar al paciente para que mantenga una buena higiene oral. Los resultados de esta revisión se deben tomar con cautela por el nivel de evidencia que arrojaron, y la recomendación general para el clínico es que, a largo plazo, estos retenedores parecen ser seguros para mantener el alineamiento de incisivos mandibulares, aunque se requieren más estudios con mayor rigor científico. No hubo conflictos de intereses y la investigación no contó con ningún tipo de financiamiento.

Background With increasing adoption of transoral robotic surgery (TORS) for oropharyngeal cancer (OPC), more patients may receive trimodality therapy. We sought to investigate outcomes and toxicities in this cohort. Methods A retrospective study of patients with OPC treated with trimodality therapy at a tertiary-care hospital, comparing those receiving bilateral vs unilateral neck radiation. Results Four hundred thirty-six patients underwent TORS, 17% receiving adjuvant chemoradiation. Of the 46 patients completing adjuvant treatment in-house, contralateral neck was spared in 20%. There were no significant differences in survival, and patient-reported outcomes in salivary function, mood, and anxiety were superior in those patients receiving unilateral neck radiation and directly correlated with mean dose to local structures. Conclusions Surgery for OPC offers the potential for reduction in radiation volumes by omitting the contralateral neck in those who may have required definitive chemoradiation. Even in patients receiving concurrent chemotherapy, unilateral neck radiation has a favorable toxicity profile without compromising survival.

Purpose: Diffuse intrinsic pontine glioma (DIPG) is the most aggressive primary pediatric brain tumor, with

Paramount to the efficacy of immune checkpoint inhibitors is proper selection of patients with adequate tumor immunogenicity and a robust but suppressed immune infiltrate. In colon cancer, immune-based therapies are approved for patients with DNA mismatch repair (MMR) deficiencies, in whom accumulation of genetic mutations results in increased neoantigen expression, triggering an immune response that is suppressed by the PD-L1/PD-1 pathway. Here, we report that characterization of the microenvironment of MMR-deficient metastatic colorectal cancer using multiplex fluorescent immunohistochemistry (mfIHC) identified increased infiltration of cytotoxic T lymphocytes (CTLs), which were more often engaged with epithelial cells (ECs) and improved overall survival. A subset of patients with intact MMR but a similar immune microenvironment to MMR-deficient patients was identified and found to universally express high levels of PD-L1, suggesting that they may represent a currently untreated, checkpoint inhibitor-responsive population. Further, PD-L1 expression on antigen-presenting cells (APCs) in the tumor microenvironment (TME) resulted in impaired CTL/EC engagement and enhanced infiltration and engagement of Tregs. Characterization of the TME by mfIHC highlights the interconnection between immunity and immunosuppression in metastatic colon cancer and may better stratify patients for receipt of immunotherapies.

RESUMEN. Antecedentes: A través del tiempo se han propuesto diferentes técnicas para realizar la remoción del adhesivo y resina remanentes luego de retirar los brackets, pero no existe un consenso entre los diferentes autores. Objetivo: el propósito de esta revisión sistemática fue identificar cuál es la técnica más adecuada para evitar injuria al esmalte durante la remoción de la resina remanente después de retirados los brackets. Métodos: Esta revisión sistemática se basó en los lineamientos de PRISMA, Para recolectar la evidencia publicada se realizó una búsqueda electrónica en diferentes bases de datos. Resultados: Se encontraron 8 artículos con una evidencia media (> de 9) los cuales fueron considerados en esta revisión sistemática. Al parecer la remoción de resina y adhesivo remanentes con ultrasonido, fresa de carburo de tungsteno de alta velocidad y piedras blancas generan la mayor pérdida de esmalte, mientras que 6 artículos proponen la fresa de tungsteno de baja velocidad como la mejor técnica. Conclusiones: Se requieren estudios aleatorizados, con grupo control, doble-ciego y una técnica de análisis del esmalte estandarizada para poder generar un nivel de evidencia alto y dar recomendaciones más acertadas para el clínico.ABSTRACT. Background: Over time different techniques have been proposed for the removal of the remaining adhesive and resin after the removal of brackets, but there is no consensus among authors. Objective: Evaluate the most appropriate technique to prevent injury to the enamel during the removal of the remaining resin after the brackets are removed. Methods: This systematic review is based on the guidelines of PRISMA, to collect the published evidence there was a various electronic databases search. Results: There were only 8 items with medium evidence (> 9) which were considered in this systematic review. Apparently removing remaining adhesive resin with ultrasound, tungsten carbide cutter high speed and white stones generate the greatest loss of enamel, while 6 articles propose the tungsten bur at low speed as the best technique. Conclusions: Randomized studies with control group, double-blind and a standardized technique of enamel analysis are required to generate a high level of evidence and give more accurate recommendations for clinicians.

The legend of the Figure currently reads: "A formula for advancing surgical system strengthening and World Health Assembly resolution 68.15 through the World Health Organization's thirteenth General Programme of Work (GPW-13). This graphic depicts the three strategic shifts outlined in GPW-13 and ties them to specific avenues for surgical system strengthening to achieve overarching goals. GPW-13 = Thirteenth General Programme of Work; NSOAPs = National Surgical, Obstetric, and Anesthesia Plans; PHC = primary healthcare; SDG 3 = Sustainable Development Goal 3; UHC = universal health coverage; WHA 68.18 = World Health Assembly resolution 68.15. " The corrected Figure legend should read: A formula for advancing surgical system strengthening and World Health Assembly resolution 68.15 through the World Health Organization's thirteenth General Programme of Work (GPW-13). This graphic depicts the three strategic shifts outlined in GPW-13 and ties them to specific avenues for surgical system strengthening to achieve overarching goals. GPW-13 = Thirteenth General Programme of Work; NSOAPs = National Surgical, Obstetric, and Anesthesia Plans; PHC = primary healthcare; SDG 3 = Sustainable Development Goal 3; UHC = universal health coverage; WHA 68.15 = World Health Assembly resolution 68.15.

BACKGROUND: Despite numerous trials assessing optimal antibiotic prophylaxis strategies for colorectal surgery, few studies have assessed real-world practice on a national scale with respect to risk of surgical site infections. OBJECTIVE: Using a large national claims database we aimed to describe current use of prophylactic antibiotics (type and duration) and associations with surgical site infection after open colectomies. DESIGN: This was a retrospective study using the Premier Perspective database. SETTINGS: Included were patient hospitalizations nationwide from January 2006 to December 2013. PATIENTS: A total of 90,725 patients who underwent an open colectomy in 445 different hospitals were included in the study. MAIN OUTCOME MEASURES: Multilevel, multivariable logistic regressions measured associations between surgical site infection and type of antibiotic used and duration (day of surgery only, day of surgery and the day after, and >1 day after surgery). RESULTS: Overall surgical site infection prevalence was 5.2% (n = 4750). Most patients (41.8%) received cefoxitin for prophylaxis; other choices were ertapenem (18.2%), cefotetan (10.3%), metronidazole with cefazolin (9.9%), and ampicillin with sulbactam (7.6%), whereas 12.2% received other antibiotics. Distribution of prophylaxis duration was 51.6%, 28.5%, and 19.9% for day of surgery only, day of surgery and the day after, and >1 day after surgery, respectively. Compared with cefoxitin, lower odds for surgical site infection were observed for ampicillin with sulbactam (OR = 0.71 (95% CI, 0.63–0.82)), ertapenem (OR = 0.65 (95% CI, 0.58–0.71)), metronidazole with cefazolin (OR = 0.56 (95% CI, 0.49–0.64)), and “other” (OR = 0.81 (95% CI, 0.73–0.90)); duration was not significantly associated with altered odds for surgical site infection. Sensitivity analyses supported the main findings. LIMITATIONS: The study was limited by its lack of detailed clinical information in the billing data set used. CONCLUSIONS: In this national study assessing real-world use of prophylactic antibiotics in open colectomies, the type of antibiotic used appeared to be associated with up to 44% decreased odds for surgical site infections. Although there are numerous trials on optimal prophylactic strategies, studies that particularly focus on factors that influence the choice of prophylactic antibiotic might provide insights into ways of reducing the burden of surgical site infections in colorectal surgeries.

RESUMEN. Introducci o n : el movimiento dental ortodoncico con apices abiertos que no han terminado su formacion radicular completa no ha sido estudiado suficientemente. Existe controversia sobre los riesgos que se pueden generar por dicho movimiento, como reabsorcion radicular o disminucion de la longitud radicular. El objetivo de esta revision sistematica es determinar los posibles efectos de alargamiento, acortamiento o reabsorcion radicular que se pudieran presentar dirante el movimiento dental ortodoncico en dientes que no han terminado su formacion radicular. M e todos: s e hizo una busqueda electronica (PubMed, Cochrane, Dentistry and oral Sciences Source, Sience Direct, Scholar Google, IdeA, ProQuest, EMBASE, Lilacs, TRIP) y una busqueda manual en La biblioteca Juan Roa Vazquez, de la Universidad El Bosque, desde 1990 a 2014. Los articulos que cumplieron con los criterios de inclusion, como ensayos clinicos aleatorizados, prospectivos, retrospectivos y de denticion mixta temprana con sistema 2 x 4, fueron evaluados por cuatro investigadores y calificados metodologicamente. Resultados: se realizo una calioficacion metodologica personalizada tomada de Lagravere y colaboradores (2005). Cuatro articulos fueron finalmente seleccionados, de los cuales tres fueron de modalidad retrospectiva: Amlani y colaboradores (2007), con 26 pacientes, encontraron reabsorcion radicular en el 8% de la muestra, sin significancia estadistica. Mavragani y colaboradores (2002), con una muestra de 146 pacientes, encontraron raices mas largas en dientes mas jovenes, y Kim y Park (2004), con 59 pacientes, encontraron mayor reabsorcion en incisivos laterales maxilares. Da Silva y colaboradores (2005), con 46 pacientes, reportaron una prevalencia de 4.4% de reabsorcion radicular en incisivos centrales. Conclusiones: esta revision sistematica debe ser tomada con cautela por el bajo y moderado nivel de evidencia encontrado. En terminos generales, no se encontro alteracion en la forma ni en la longitud radicular cuando los dientes con apices abiertos fueron sometidos a fuerzas ortodoncicas fijas. El riesgo de reabsorcion apical estuvo mas relacionado con la duracion del tratamiento, en dientes con apices tanto abiertos como cerrados. Palabras clave: ortodoncia, apice del diente, reabsorcion radicular, revision sistematica. Abstract. Introduction : orthodontic tooth movement with open apices which have not completed root formation has not been sufficiently studied. There is controversy about the risks associated to this movement, such as root resorption and decreased root length. The goal of this systematic review is to determine the possible effects of lengthening, shortening, or root resorption possibly occurring during orthodontic movement in teeth that have not completed root formation. Methods: electronic search (PubMed, Cochrane, Dentistry and Oral Sciences Source, Science Direct, Google Scholar, IdeA, ProQuest, Embase, Medline, Lilacs, TRIP) and manual search at Universidad El Bosque Juan Roa Vazquez Library since 1990 to 2014. Articles meeting the inclusion criteria, such as randomized clinical trials, prospective and retrospective studies, and studies in early mixed dentition with 2 x 4 system, were evaluated and methodologically qualified by four researchers. Results: this study involved a custom methodological rating taken from Lagravere et al (2005). Four articles were finally selected, three of which were retrospective: Amlani et al (2007), with 26 patients, found root resorption in 8% of the sample, with no statistical significance. Mavragani et al (2002), with a sample of 146 patients, found longer roots in younger teeth, and Kim & Park (2004), with 59 patients, found higher resorption in maxillary lateral incisors. Da Silva et al (2005), with 46 patients, reported a prevalence of 4.4% in root resorption in central incisors. Conclusions: this systematic review must be taken cautiously due to the low and moderate level of evidence found. In general terms, there were no alterations in terms of root length or shape when teeth with open apices were subjected to fixed orthodontic forces. The risk of apical resorption was more related to treatment duration in teeth with both open and closed apexes. Key words: orthodontics, tooth apex, root resorption, systematic review.

Introducción.El blanqueamiento dental es de los procedimientos más solicitados a los odontólogos. Desde los años 90 han aumentado las técnicas y presentaciones de los productos usados para este procedimiento. Por el aumento en la demanda del blanqueamiento dental, sepuede encontrar gran número de estudios en la literatura, por lo cual es difícil sacar conclusiones válidas sobre la efectividad a largo plazo de las técnicas disponibles.Objetivo.El objetivo de esta revisión sistemática es determinar si el blanqueamiento dental es efectivo a largo plazo, cuál sistema de blanqueamiento es el más efectivo, cuánto perdura en el tiempo y cuáles son las variables que intervienen en el éxito. Materiales y métodos.Los artículos utilizados en esta revisión son ensayos clínicos aleatorizados, buscados electrónica y manualmente entre 1980 y el 2013, en diferentes bases de datos.Resultados.De 4.581 artículos encontrados, se seleccionaron 8 artículos para incluir en la revisión, ya que cumplían con los criterios establecidos. Después de seleccionar los artículos definitivos para la revisión, se hizo una evaluación metodológica de estos, por medio de la cual se encontró que el nivel de evidencia fue alto en tres artículos, medio en cuatro y bajo en uno.Conclusión.Teniendo en cuenta la buena ‘evidencia’ que se encontró, se concluye que: la efectividad del blanqueamiento a largo plazo no depende de la técnica del blanqueamiento empleada. El cambio de color registrado durante el blanqueamiento dental fue similar en todos los grupos evaluados. El blanqueamiento en casa, es un tratamiento efectivo. A pesar de que se mantienen los cambios de color logrados con el blanqueamiento, se presenta una recidiva de leve a moderada.

3581 Background: Half of patients diagnosed with colorectal cancer (CRC) develop metastases and most are CRC liver metastasis (CRLM). A mere 20% of these patients undergo complete resection of their liver disease and 5-year overall survival (OS) is only 50%. We hypothesized that we could identify a specific molecular profile associated with extraordinary survivorship in CRLM patients that would more precisely inform underlying tumor biology beyond standard clinical and pathologic features. Methods: Tumor samples were identified from patients who underwent curative resection. Patients with disease-specific survival (DSS) ≥10 years following resection were compared to those with ≤2-year survival (10yr vs. 2yr). Evaluable DNA was obtained from 36 cases (2yr, n = 17; 10yr, n = 19) then sequenced and analyzed with MSK-IMPACT (MSK-I), a hybridization capture, next generation sequencing platform. Differentially altered genes in 10yr vs. 2yr cohorts were identified (Fisher’s exact). Findings in the extraordinary survivors group were validated using MSK-I in an independent cohort of 965 metastatic CRCs (metCRCs). Kaplan-Meier estimates and log-rank test were used. Results: In the 2yr group, we noted higher clinical risk scores and more complex chemotherapy regimens vs. the 10yr group. Molecularly, mutually exclusive KRAS and TP53 mutations were noted in the 10yr group, whereas significant co-occurrence of KRAS and TP53 mutations was seen in the 2yr group. Further, we noted significant enrichment of VEGF copy number gains in the 2yr group vs. the 10yr group. APC mutation was equally common. In the validation cohort, KRASmut/TP53wt and TP53mut/KRASwt patients (median OS of 10 and 15 years respectively) had significantly better OS than the co-occurring KRASmut / TP53mutpatients (median OS of 4.9 years; (P = 0.0001)). Conclusions: Single mutation of either KRAS or TP53 is associated with better outcomes than co-occurring KRAS/TP53 mutations in metCRC. These data demonstrate use of an extraordinary survivor cohort to identify a molecular profile associated with significant survival differences in an independent cohort of metCRC patients.

587 Background: Few markers reliably identify colorectal cancer (CRC) patients at risk of recurrence and death. SMAD4 loss occurs in 10-20% of cases and has shown promise in identifying high-risk stage II/III patients. We examined SMAD4 status and association with clinical/pathologic features in 446 stage I-IV CRC patients at Memorial Sloan Kettering (MSK). Methods: Patients undergoing curative resection were included (1981-2010). Familial polyposis syndrome patients and those with inadequate tissue were excluded. Tissue microarrays were constructed (n=364). Immunohistochemistry for SMAD4 and mismatch repair (MMR) proteins was completed. SMAD4 nuclear stain intensity was scored (scale=0-3; 0=loss). On whole sections, MMR proteins (present or absent), tumor-infiltrating lymphocytes (TILs) and peritumoral lymphocyte aggregates (PLAs) were scored (scale=0-3). Associations between clinical/pathologic features and SMAD4 loss vs. retention were analyzed. Kaplan-Meier estimates and log-rank test were used for recurrence-free and overall survival analyses (RFS and OS). Results: SMAD4 loss was noted in 13%. Median age at diagnosis was 53 years, and 51% were male. The cohort consisted of 61% hindgut tumors and 62% stage II/III patients. With up to 33 years of follow-up, the mean was 6 years. SMAD4 loss correlated with higher tumor and nodal stage, adjuvant therapy use, and lower TIL and PLA scores (pmedian) were noted to have worse OS with SMAD4 loss (p

Introducción.En esta revisión sistemática se evaluó la efectividad de las férulas o placas Essix® como parte de la retención en ortodoncia, la relación costo-beneficio y los posibles efectos secundarios que se pueden presentar con su uso.Métodos. La búsqueda manual de estudios clínicos se llevó a cabo el 29 de agosto de 2013 y, la computadorizada, el 2 de septiembre de 2013. Los criterios de selección fueron: 1) estudios clínicos prospectivos, retrospectivos de asignación aleatoria, y metanálisis; 2) estudios en humanos; 3) estudios que compararan placas Essix® con retenedores removibles; 4) pacientes que hubieran terminado el tratamiento de ortodoncia; 5) tiempo de observación de dos años o más; 6) estudios en todos los idiomas; 7) estudios desde 1990 hasta 2013.Resultados.Se encontraron 17 artículos con potencial de inclusión, de los cuales se excluyeron 15 por no cumplir los criterios de selección, lo que resultó en la inclusión de dos estudios solamente. La efectividad de la placa Essix® omo alternativa de retención es mayor en comparación con la de Hawley; sin embargo, en relación con la retención del ancho intercanino, la longitud del arco inferior y los contactos de oclusión, no hubo diferencias significativas. La relación costo-beneficio y los efectos secundarios no se pudieron evaluar debido a la falta de evidencia.Conclusiones. La placa Essix® se encontró más efectiva para mantener la posición de los incisivos inferiores durante el período de retención en comparación con la placa de Hawley; sin embargo, el índice de irregularidad tiende a volver a su valor inicial a los dos años después de la retención

Introducción: El propósito de esta revisión sistemática fue evaluar la efectividad de la fibrotomía supracrestal circunferencial como procedimiento coadyuvante en la estabilidad del tratamiento ortodóntico.Métodos: Se realizó una búsqueda electrónica en diferentes bases de datos. Los criterios de inclusión fueron: artículos entre el año 1980-2013, realizados en humanos, estudios que evaluaran la efectividad del procedimiento en un período no menor a 1 año y pacientes que no hubieran sido sometidos a tratamientos periodontales similares.Resultados: Un total de 268 títulos fueron encontrados en bases de datos electrónicas y en la búsqueda manual no se encontraron artículos relacionados con el tema. Un total de 37 abstracts fueron revisados y de éstos se excluyeron 34 por no relacionarse con el tema, finalmente fueron seleccionados tres artículos. La fibrotomía supracrestal circunferencial se considera un procedimiento efectivo para prevenir la recidiva a corto y largo plazo, siendo más efectiva para disminuir la recidiva rotacional que otros tipos de movimiento. El tiempo ideal para realizar la FSC no es conocido y la decisión del clínico es arbitraria y empírica.Conclusiones: Se ha observado una tendencia a la recidiva relacionados con diversos factores como el efecto de la musculatura perioral, la oclusión, el aumento del ancho intercanino, la dirección del crecimiento mandibular, la discrepancia óseo-dental y la influencia de los tejidos periodontales y gingivales. Las conclusiones de esta revisión sistemática deben ser consideradas con cautela debido a que los estudios presentan un nivel de evidencia bajo-moderado. Se requieren ensayos clínicos aleatorizados prospectivos para soportar estos hallazgos

Introduction: the objective of this study was to evaluate the periodontal effects of fixed retainers in the long term. Methods: a search in electronic databases (PubMed, Cochrane Library, Science Direct, Embase, ProQuest, Ebsco, Biomed Central, Medline, Lilacs, and Google Scholar) and a manual search with no language restrictions. The inclusion criteria were: randomized clinical trials and meta-analysis, prospective and retrospective studies, studies in humans, clinical and radiographical studies evaluating the periodontium, performed during the 1987-2014 period, up to 10 years of follow-up. Four authors extracted data from the selected studies independently. Results: after applying the inclusion criteria, we selected 4 studies in which a total of 405 patients were evaluated. All the studies were longitudinal and retrospective. There was a greater prevalence of gingival recessions, especially in mandibular incisors, which are more vulnerable. There were no significant changes in terms of alveolar bone index or calculus index. The survival rate of fixed retainers was 50% or higher. Due to the heterogeneity of the selected studies, including difference in study population, differences in methods to assess the intervention, and follow-up periods, it was impossible to quantify the variables to perform a meta-analysis. Conclusions: the selected studies had a middle level of evidence. The greatest gingival recessions occurred with the use of fixed retainers in a long time; however, there is no alteration of the alveolar bone level. The studies recommend encouraging patients to maintain good oral hygiene. The findings of this review should be cautiously taken due to the resulting level of evidence, and the general recommendation for clinicians is that, in the long run, these retainers appear to be safe to maintain the alignment of mandibular incisors, although more studies with greater scientific rigor are required. There were no conflicts of interest and this study did not have any kind of financial support.

To determine the causes and time course of onset of functional asplenia in adults, a four-part investigation was conducted. This consisted of a review of the world's literature, a survey of colleagues, a detailed study of 4,476 consecutive liver-spleen scans in three hospitals, and continued monitoring of 3,500 scans in five hospitals. Based on the findings, a classification was proposed of the causes of functional asplenia. The two major etiologies were circulatory disturbances and effects directly on splenic reticuloendothelial cells. The time course varied from the essentially instantaneous onset of functional asplenia in patients with acute splenic artery obstruction, to a prolonged and gradual onset in those with chronic damage to splenic reticuloendothelial cells. Functional asplenia was found in 0.14% of the adults who had liver-spleen scans for other indications.