The marginal mandibular branch of the facial nerve (MMB) has a significant variation in relation to the lower border of the mandible (LBM). That is why it is important to know its topographical description to prevent damage in submandibular surgical procedures. The objective of this study was to determine the distance between the MMB and LBM based on descriptive studies carried out on human corpses and surgical patients. A systematic review of literature in MEDLINE, "Science Citation Index Expanded" of Web of Science (ISI) databases and manual search was performed. The articles with number of samples greater than or equal to 10 facial samples and recording of measurements between the MMB and the LBM or Gonion were selected. From the selected articles, the authors registered year of publication, country of origin, number of samples, sample type (fresh, embalmed body/fixed cadavers or surgical patient), distribution percentage of the MMB in relation to LBM, average and maximum distance between MMB and LBM or Gonion. The results were presented in tables with descriptive statistic. Seventeen articles describing measurements of the distance between MMB and the lower border of the mandible carried out in cadavers and patients were selected. In these articles a total of 1,408 samples were dissected. The maximum distance observed was 4.01 cm (mean±SD 1.64±0.92 cm, Min= 0.69; Max= 4.01). Several reports suggest that an incision 2 cm below the lower border of the mandible would be enough to avoid damage of the MMB. However, according to the maximal distances registered, such an incision might involve risk for the MMB. For this reason, we propose that the MMB of facial nerve should be at least 4 cm below the lower border of the mandible.

La rama mandibular marginal del nervio facial (RMM) posee variaciones significativas en su relación con el margen inferior de la mandíbula (MIM), siendo importante su descripción topográfica para evitar su daño en procedimientos quirúrgicos submandibulares. El objetivo fue determinar la distancia RMM y MIM observadas en humanos. Se realizó una revisión sistemática de la literatura en las bases de datos MEDLINE, "Science Citation Index Expanded" de Web of Science (ISI) y una búsqueda manual. Se seleccionaron artículos con análisis de 10 o más muestras y que registraran la distancia entre el RMM y el MIM o Gonion. Se registró autor, países de origen, condición de la muestra, número de muestras, distancias promedio y máximas registradas. Los resultados se analizaron mediante estadística descriptiva y presentada en tablas. Se seleccionaron 17 artículos con mediciones de las distancias entre el RMM y MIM tanto en cadáveres como pacientes. En total, 1,408 muestras fueron disecadas. La distancia máxima registrada fue de 4.01 cm (promedio±DE 1.64±0.92 cm, Min= 0,69; Max= 4,01). Diversos reportes sugieren que una incisión a 2 cm bajo el margen inferior de la mandíbula sería suficiente para evitar el daño al RMM. Sin embargo, con las distancias máximas observadas dicha incisión podría generar un daño. Por lo tanto, esta revisión sugiere la presencia del RMM a lo menos a 4 cm bajo el margen inferior de la mandíbula.

Este trabalho analisa a política exterior chilena das três últimas décadas tendo como pano-de-fundo a situação interna do País e seus reflexos na inserção internacional do Chile. Neste sentido, ressalta a importância da relação democracia-política externa e, principalmente, os elementos de continuidade e mudança que afetam esta relação durante os últimos trinta anos.

This article analyses the last three decades of Chilean foreign policy, having as background the country's internal situation and its reflects on Chile's international insertion. By doing that, it emphasises the import of the relation democracy-foreign policy and, mainly, the elements of continuity and change that affect this relation during the last thirty years.