Rotaciones de los dientes permanentes en la clínica de ortodoncia / No disponible

Introducción. El objetivo de este estudio es medir la frecuencia e intensidad de las rotaciones en incisivos y caninos permanentes y premolares, superiores e inferiores, y relacionarlas con variables biométricas como anchura intercanina e intermolar, tamaño dentario y discrepancia de longitud de arcada. Material y métodos. Se realizó un estudio observacional retropectivo utilizando modelos de estudio de 50 casos no tratados ortodóncicamente y elegidos al azar. Se requería la presencia de todos los dientes permanente de primer molar a primer molar y la ausencia de agenesias o supernumerarios. Se midieron las rotaciones de cada diente, diámetro mesiodistal, anchuras intercanina e intermolar y discrepancia de longitud de arcada superior e inferior. Para el análisis estadístico se determinó la media, desviación típica e intervalo de confianza del 95% para la media de las magnitudes estudiadas; la prueba de la de Student y el ANOVA con prueba de Tukey para la comparación de 2 y 3 medias respectivamente, y el coeficiente de correlación r-Pearson. Resultados. El porcentaje de dientes rotados en cada tipo de diente osciló entre 48 y 82% y no se encontraron diferencias estadísticamente significativamente mayores que el resto, del 80 y 82% respectivamente. No se encontró dimorfismo sexual ni bilateral, ni correlaciones significativas entre las rotaciones y las variables biométricas, excepto entre la discrepancia de longitud de arcada superior negativa y el número de dientes rotados en dicha arcada (r=-0,327; p<0,05) (AU)

Introduction. The aim of this study is to measure rotation frequency and intensity in upper and lower permanent incisive, permanent canines, and bicuspids, and to relate them to biometric variables such as intercanine and intermolar width, tooth size and arch length discrepancies. Material and methods. Retrospective observation was made using study catss of 50 orthodontically untreated cases selected at random. The presence of all permanent teeth from the first molar to the other was a pre-requesite, as was the absence of agenesis or supernumerary. Measurements of the rotation of each tooth, mesidistal diameter, intercanine and intermolar width, and upper and lower arch length discrepancies were taken. The statistical analysis consisted of determining mean, standard deviation, with a 95% confidence interval for the mean of the values under study. Student T test and ANOVA using Tukey test to compare 2 and 3 means respectively; and r-Pearson correlation coefficient. Results. The percentage of rotated teeth for each type fluctuated between 48$ and 82% with no statistically significant differences between them being found, except for teeth 3.3 and 4.2 which revealed significantly higher frequencies than the remainder. 80% and 82% respectively. No sexual or bilateral dimorfism were found, except for upper arch length discrepancy with a negative value and the number of rotated teeth in the upper arch (r=-0.327; p<0.05)

Using Bayesian networks in the construction of a bi-level multi-classifier. A case study using intensive care unit patients data.

Combining the predictions of a set of classifiers has shown to be an effective way to create composite classifiers that are more accurate than any of the component classifiers. There are many methods for combining the predictions given by component classifiers. We introduce a new method that combine a number of component classifiers using a Bayesian network as a classifier system given the component classifiers predictions. Component classifiers are standard machine learning classification algorithms, and the Bayesian network structure is learned using a genetic algorithm that searches for the structure that maximises the classification accuracy given the predictions of the component classifiers. Experimental results have been obtained on a datafile of cases containing information about ICU patients at Canary Islands University Hospital. The accuracy obtained using the presented new approach statistically improve those obtained using standard machine learning methods.

Mortality prediction in cardiac surgery patients: comparative performance of Parsonnet and general severity systems.

BACKGROUND: Our purpose was to assess the performance of general severity systems (Acute Physiology and Chronic Health Evaluation [APACHE], Simplified Acute Physiology Score [SAPS], and Mortality Probability Models [MPM]) and to compare them with the Parsonnet score to predict mortality after cardiac surgery. METHODS AND RESULTS: This was a prospective observational study of 465 cardiac surgery patients in a tertiary referral center. Probabilities of hospital death for patients were estimated by applying the 4 models and were compared with actual mortality rates. Performance of the 4 systems was assessed by evaluating calibration with the Hosmer-Lemeshow goodness-of-fit test and discrimination with receiver operating characteristic (ROC) curves. chi2 values were 3. 71 for Parsonnet, 4.52 for MPM II0, 4.30 for MPM II24, 5.16 for SAPS II, and 10.57 for APACHE II. The area under the ROC curve was 0.857 for Parsonnet, 0.783 for MPM II0, 0.796 for MPM II24, 0.771 for SAPS II, and 0.803 for APACHE II. CONCLUSIONS: In our experience, the Parsonnet score performs very well, with calibration and discrimination very high, better than general severity systems, and it is an appropriate tool to assess mortality in cardiac surgery patients. In our experience, the general severity systems perform well to predict mortality after cardiac surgery, with high calibration of MPM II24, MPM II0, and SAPS II; minor calibration for APACHE II; and high discrimination for 3 general systems, but not as well as the Parsonnet score.

Field evaluation of a diagnostic protocol for Chagas' disease and rangeliosis.

The present paper evaluates the protocol for the diagnosis of Chagas' diseases and rangeliosis that is suitable for use in remote and scarcely populated rural areas. Beginning with a blood sample taken by venipuncture in the rural dispensary from 350 inhabitants of Caserío La Sierra, Cojedes State, Venezuela, samples were analyzed at a laboratory located at a distance of 150 Km. Each blood sample was analyzed for blood and clot culture, artificial xenodiagnosis, inoculation into mice, complement fixation reaction (CFR), and indirect fluorescent antibodies test (IFA). Nine isolates of trypanosomes were obtained and identified as Trypanosoma rangeli, 29.4% of the blood samples showed seropositivity for Trypanosoma cruzi, 7.1% of total of persons between 6 and 18 years were found infected with T. rangeli, suggesting active transmission of this trypanosome in an endemic area for Chagas' disease. Results indicate that this protocol of study is reliable, economical and sufficiently versatile to study both rangeliosis and Chagas' disease.

Facial differences between northern and southern European children.

Cephalometric comparison of Spanish and Scandinavian children with good occlusions finds a more horizontal mandible and more protrusive incisors in the Spanish sample.