Analysis of the Internal and External Morphology of the Mandibular First Molar in a Chilean Sub-Population Using Cone-Beam Computed Tomography / Análisis de la Morfología Interna y Externa del Primer Molar Mandibular en una Subpoblación Chilena Mediante Tomografía Computarizada de Haz Cónico

SUMMARY: The mandibular first molar (MFM) commonly presents two roots with two canals in the mesial root and one or two canals in the distal root. However, morphological variations have been described in different populations, which must be considered when planning endodontic treatment. The aim of this study was to analyze the internal and external morphology of the MFM in a Chilean sub-population using cone-beam computed tomography (CBCT) images. An in vivo cross-sectional, descriptive, and observational study was conducted using CBCT exams from 351 right and left MFM. The data were analyzed by descriptive statistics using the Chi- Square test for categorical variables, Fisher's exact test, the Mann-Whitney U non-parametric test for two independent samples, and the Wilcoxon non-parametric test for related samples. Of the total sample, 1 root was observed in 2.27 % of the cases, 2 roots in 93.73 %, and 3 roots in 4 %. In relation to the number of canals, 71.23 % of the MFM showed 3 root canals, 16.81 % 4 canals, 9.69 % 2 canals, and 2.28 % 1 canal. Of all the studied cases, 2.3 % had a C-shaped anatomy. In terms of morphology, using Zhang's classification, variant 3 was observed in 71.23 %, variant 4 in 12.82 %, variant 1 in 9.67 %, variant 6 in 4 %, and variant 8 in 2.28 %. In conclusion, the morphology of the MFM is variable in a Chilean sub-population, and these variations must be considered before and during endodontic therapy. CBCT proved to be an effective tool for the in vivo study of tooth morphology.

El primer molar mandibular (MFM) comúnmente presenta dos raíces con dos canales en la raíz mesial y uno o dos canales en la raíz distal. Sin embargo, se han descrito variaciones morfológicas en distintas poblaciones, las que se deben tener en consideración al momento de planificar el tratamiento endodóntico. El objetivo de este estudio fue analizar la morfología interna y externa del MFM en una sub población chilena mediante el uso de imágenes de tomografía computarizada Cone Beam (CBCT). Se realizó un estudio transversal, descriptivo y observacional in vivo empleando exámenes CBCT de 351 MFM tanto derechos como izquierdos. Los datos se analizaron mediante estadística descriptiva empleando la prueba Chi-Cuadrado para variables categóricas, el test exacto de Fisher, la prueba no paramétrica de U-Mann-Whitney para dos muestras independientes y la prueba no paramétrica de Wilcoxon para muestras relacionadas. Del total de la muestra se observó 1 raíz en un 2.27 % de los casos, 2 raíces en 93.73 % y 3 raíces en un 4 %. En relación al número de canales un 71.23 % de los MFM mostraron 3 canales radiculares, un 16.81 % 4 canales, un 9.69 % 2 canales y un 2.28 % 1 canal. Del total de los casos estudiados un 2.3 % se presentó anatomía en forma de C. En relación a la morfología, empleando la clasificación de Zhang, se observó en un 71.23 % la variante tipo 3, en un 12.82 % la variante tipo 4, en un 9.67 % la variante tipo 1, en un 4 % variante tipo 6 y en un 2,28 % variante tipo 8. En conclusión, la morfología del MFM es variable en una subpoblación chilena y estas variaciones deben ser consideradas antes y durante la terapia endodóntica. El CBCT demostró ser una herramienta eficaz para el estudio in vivo de la morfología dentaria.

Completely converting a blood service region to the use of safer plasma.

BACKGROUND: Three types of plasma are widely available for transfusion. Two plasma components, FFP donor retested (FFP-DR), and solvent/detergent-treated plasma (SDP), are now considered to be safer from infectious complications than FFP. STUDY DESIGN AND METHODS: A large regional blood center attempted to provide FFP-DR exclusively to all its 42 hospitals. Significant planning, increases in computer capabilities, and expansion of component storage areas were completed before initiation of this program. RESULTS: During the first 6 months of the FFP-DR program, the blood center was not able to supply the entire region exclusively with FFP-DR. Consequently, SDP was utilized to supplement the program and to successfully and completely convert the region's 42 hospitals to the use of safer plasma. CONCLUSION: Two new plasma components were utilized to completely convert a blood service region to the use of safer plasma.

Expanded liver donor age over 60 years for hepatic transplantation.

With a growing discrepancy between the number of liver candidates and donors, traditional donor selection criteria have been greatly changed to meet the need for donor livers. Older donors are a readily available source of livers that can significantly augment the donor pool. Our series demonstrated that the course and the outcome of orthotopic liver transplantation were not influenced by donor age, as indicated by the absence of significant differences in the incidence of primary nonfunction, arterial and biliary complications, postoperative function tests, and graft and patient survival. These results indicate that age per se should not be considered as a major criteria for accepting or rejecting donor livers for transplantation.