External validation of two clinical prediction models for mortality in COVID-19 patients (4C and NEWS2), in three centers in Medellín, Colombia: Assessing the impact of vaccination over time.

OBJECTIVES: External validation of the 4C and NEWS2 scores for the prediction of in-hospital mortality in COVID-19 patients, and evaluation of its operational performance in two time periods: before and after the start of the vaccination program in Colombia. METHODS: Retrospective cohort in three high complexity hospitals in the city of Medellín, Colombia, between June 2020 and April 2022. RESULTS: The areas under the ROC curve (AUC) for the 4C mortality risk score and the NEWS2 were 0.75 (95% CI 0.73-0.78) and 0.68 (95% CI 0.66-0.71), respectively. For the 4C score, the AUC for the first and second periods was 0.77 (95% CI 0.74-0.80) and 0.75 (95% CI 0.71-0.78); whilst for the NEWS2 score, it was 0.68 (95% CI 0.65-0.71) and 0.69 (95% CI 0.64-0.73). The calibration for both scores was adequate, albeit with reduced performance during the second period. CONCLUSIONS: The 4C mortality risk score proved to be the more adequate predictor of in-hospital mortality in COVID-19 patients in this Latin American population. The operational performance during both time periods remained similar, which shows its utility notwithstanding major changes, including vaccination, as the pandemic evolved.

Can gray values be converted to Hounsfield units? A systematic review.

OBJECTIVES: The purpose of this systematic review was to answer the focus question: "Could the gray values (GVs) from CBCT (cone beam computed tomography) be converted to Hounsfield units (HUs) in multidetector computed tomography (MDCT)?" METHODS: The included studies try to answer the research question according to the PICO strategy. Studies were gathered by searching several electronic databases and partial grey literature up to January 2021 without language or time restrictions. The methodological assessment of the studies was performed using The Oral Health Assessment Tool (OHAT) for in vitro studies and the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) for in vivo studies. The Grading of Recommendations Assessment, Development and Evaluation (GRADE system) instrument was applied to assess the level of evidence across the studies. RESULTS: 2710 articles were obtained in Phase 1, and 623 citations remained after removing duplicates. Only three studies were included in this review using a two-phase selection process and after applying the eligibility criteria. All studies were methodologically acceptable, although in general terms with low risks of bias. There are some included studies with quite low and limited evidence estimations and recommendation forces; evidencing the need for clinical studies with diagnostic capacity to support its use. CONCLUSIONS: This systematic review demonstrated that the GVs from CBCT cannot be converted to HUs due to the lack of clinical studies with diagnostic capacity to support its use. However, it is evidenced that three conversion steps (equipment calibration, prediction equation models, and a standard formula (converting GVs to HUs)) are needed to obtain pseudo Hounsfield values instead of only obtaining them from a regression or directly from the software.

Evaluation of the nasal septum and depth of palatal arch in different facial vertical patterns: A Cone-Beam Computed Tomography Study.

OBJECTIVE: The purpose of this study was to evaluate the nasal septum and the depth of posterior palatal arch in the different facial vertical patterns using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 143 CBCTs were analysed (53 normodivergents, 26 hypodivergents, and 64 hyperdivergents) using the software Real Scan 2.2. On the coronal view, the following measurements were taken, palatal interalveolar length (PIL), palatal arch depth (PAD), maxillopalatal arch angle (MPAA), septal vertical length (SVL), deviated septal length (DSL), and deviated septal curve angle (DSCA). Using the program Stata v16.0, we obtained the mean, standard deviation and median values. The identification of significant differences between facial biotypes was performed using the one-way ANOVA test and H of Kruskal-Wallis test, considering a significance level of 0.05. RESULTS: The hypodivergent group got the highest PIL and MPAA (49.6mm and 118.1° respectively), with statistically significant differences (P<0.05) between this group and the hyperdivergent group. Statistically significant differences were found by gender for the SNMeGo, PFH, AFH, and the relationship between the facial heights, where the males had the highest values. Additionally, PIL and SVL also had the highest values for males (48.8mm and 63.6mm respectively). CONCLUSIONS: Patients presenting with greater hyperdivergence have shorter interalveolar distances and smaller maxillopalatal arch angles.

Evaluation of the palatal bone in different facial patterns for orthodontic mini-implants insertion: A cone-beam computed tomography study.

OBJECTIVE: Evaluate the height, thickness and cortical density of the palatal bone of adults with different vertical facial patterns using Cone-Beam Computed Tomography (CBCT). METHODS: This study analyzed 75 CBCTs of patients between 18 and 35 years old (45 men and 30 women). The CBCTs were classified into three groups based on their facial pattern: normodivergent, hypodivergent and hyperdivergent as determined from lateral cephalograms synthesized from the CBCTs. The height, cortical thickness and cortical density of the palatal bone were measured at 4, 8, 12, 16 and 20mm posterior to the incisive foramen, and at 3, 6 and 9mm lateral to the midpalatal suture. ANOVA with Tukey post-hoc tests were used for analysis of the data, at significance level of p< 0.05. RESULTS: The hypodivergent pattern had a significant difference and the greatest height and cortical thickness of the palatal bone, followed by the hyperdivergent and the normodivergent patterns. No significant differences were found in minimum and maximum values of cortical density. CONCLUSION: The palatal bone is a favorable anatomical area to install different orthodontic temporary anchorage devices (TADs), where individuals with the hypodivergent vertical facial pattern have a higher height and cortical thickness of the palatal bone, followed by the hyperdivergent pattern and finally the normodivergent pattern. No significant differences in the cortical density of the palatal bone in the three facial patterns were found.

Evaluation of the palatal bone in different facial patterns for orthodontic mini-implants insertion: A cone-beam computed tomography study

ABSTRACT Objective: Evaluate the height, thickness and cortical density of the palatal bone of adults with different vertical facial patterns using Cone-Beam Computed Tomography (CBCT). Methods: This study analyzed 75 CBCTs of patients between 18 and 35 years old (45 men and 30 women). The CBCTs were classified into three groups based on their facial pattern: normodivergent, hypodivergent and hyperdivergent as determined from lateral cephalograms synthesized from the CBCTs. The height, cortical thickness and cortical density of the palatal bone were measured at 4, 8, 12, 16 and 20mm posterior to the incisive foramen, and at 3, 6 and 9mm lateral to the midpalatal suture. ANOVA with Tukey post-hoc tests were used for analysis of the data, at significance level of p< 0.05. Results: The hypodivergent pattern had a significant difference and the greatest height and cortical thickness of the palatal bone, followed by the hyperdivergent and the normodivergent patterns. No significant differences were found in minimum and maximum values of cortical density. Conclusion: The palatal bone is a favorable anatomical area to install different orthodontic temporary anchorage devices (TADs), where individuals with the hypodivergent vertical facial pattern have a higher height and cortical thickness of the palatal bone, followed by the hyperdivergent pattern and finally the normodivergent pattern. No significant differences in the cortical density of the palatal bone in the three facial patterns were found.

RESUMO Objetivo: Avaliar a altura, a espessura e a densidade cortical do osso palatino em adultos com diferentes padrões faciais verticais, utilizando a tomografia computadorizada de feixe cônico (TCFC). Métodos: O presente estudo analisou 75 TCFCs de pacientes com idades entre 18 e 35 anos (45 homens e 30 mulheres). As TCFCs foram classificadas em três grupos, de acordo com seus padrões faciais: normodivergentes, hipodivergentes e hiperdivergentes, conforme determinado na radiografia cefalométrica lateral reconstruída das TCFCs. Altura, espessura e densidade cortical do osso palatino foram aferidas a 4, 8, 12, 16 e 20 mm para posterior do forame incisivo e a 3, 6 e 9 mm lateralmente à sutura transpalatina. Os testes ANOVA e post-hoc de Tukey foram utilizados para análise dos dados, com nível de significância de p< 0,05. Resultados: O padrão hipodivergente apresentou uma diferença significativa e a maior altura e espessura cortical do osso palatino, seguido pelos padrões hiperdivergente e normodivergente. Nenhuma diferença estatisticamente significativa foi encontrada nos valores mínimos e máximos da densidade cortical. Conclusão: O osso palatino é uma área anatomicamente favorável para instalar diferentes dispositivos de ancoragem temporária. Indivíduos com padrão facial vertical hipodivergente apresentam maior altura e espessura cortical do osso palatino, seguido do padrão hiperdivergente e finalmente do padrão normodivergente. Não foi encontrada qualquer diferença significativa na densidade cortical do osso palatino entre os três padrões faciais.

Advances in seismic research of adobe houses

Seismic simulation method is used in this study by carrying out pseudo dynamic and forced vibration tests to investigate the behavior of adobe masonry structures. Two types of two-story one bay speciments were built to be used in the tests. Following traditional practices, one full scale specimen and one half scale specimen were built for this purpose. Results of pseudo dynamic tests are summarized in this paper and they are compared with others obtained from previous experiences in similar one half scale speciments by using different experimental techniques. Strength values reported in those experiences are higher than strength values obtained by pseudo dynamic tests. A reasonable correlation was shown between theoretical approach and pseudo dynamic tests results (AU)

Ensayos de simulación sísmica en un modelo mixto de adobe y quincha

Con la finalidad de investigar el comportamiento sísmico de las edificaciones mixtas de adobe y quincha se llevaron a cabo ensayos de vibración forzada, estático de carga cíclica y seudo dinámicos sobre un modelo a escala natural. el presente documento resume los principales resultados obtenidos en los ensayos y el comportamiento experimental observado. Adicionalmente se comparan algunas características del modelo de adobe en similares condiciones (AU)

Avances en la investigación sísmica de casas de adobe

El método de simulación sismica es usado en este estudio, realizando pruebas experimentales de vibración forzada y seudo dinámicas para investigar el comportamiento de estructuras de mampostería de adobe. Dos tipos de especímenes de dos pisos y de un solo ambiente fueron fabricados para usarse en las pruebas, uno a escala natural y el otro a escala mitad se construyeron siguiendo las prácticas tradicionales para este propósito. Los resultados de las pruebas seudo dinámicas son resumidos en este trabajo y son comparados con otros obtenidos en experiencias anteriores en especímenes a escala mitad mediante la aplicación de técnicas experimentales. Los valores de la resistencia reportados en aquellas experiencias son mayores que los obtenidos en las pruebas seudo dinámicas. Además se muestra una razonable correlación entre el método teórico y los resultados de las pruebas seudo dinámicas (AU)