Discrepancia anteroposterior en registro de relación céntrica con apoyo central intraoral en cubetas rodetes acrílicas (BOPAYACU) e inducción manual en adultos mayores desdentados totales / Anteroposterior discrepancy in centric relation record with intraoral central support in acylic impaction cups (BOPAYACU) and manual induction in edentulous older adults

Objetivo: Comparar la discrepancia anteroposterior medida a nivel de la platina incisiva de 2 métodos de registro intermaxilar en la misma sesión que la im-presión definitiva en adultos mayores desdentados totales. Materiales y métodos. Se incluyeron en el es-tudio 20 pacientes (n=20) con edad promedio de 70 años. En cada uno de ellos se obtuvieron registros intermaxilares con cubetas rodete de acrílico: uno con inducción manual (IM) y otro autoinducido con el sistema de cubeta rodete de acrílico y apoyo central único utilizando una superficie palatina de registro curva (BYC). Los modelos fueron montados en un ar-ticulador Whip Mix modelo 2240 al que se le adicio-nó un dispositivo de papel milimetrado, Orthodent, a nivel de la platina incisiva, para registrar las dife-rencias existentes entre las posiciones obtenidas. El análisis estadístico se llevó a cabo mediante el cálcu-lo de intervalos de confianza (95%) para las diferen-cias medias y prueba de t de student para datos apa-reados (nivel de significancia: α<0,05). Resultados. En el plano mesiodistal a nivel de la platina incisiva se encontró diferencia estadísticamente significativa entre las dos variables de registro (p<0,001). A este nivel el BYC proporcionó registros más retrusivos que IM. Media aritmética (desviaciones estándar) en milímetros: 3,82 (2,1). Conclusión. El sistema de re-gistro con cubetas rodete acrílicas y BYC incorpora-do a las mismas proporciona un registro intermaxi-lar más retrusivo que IM en adultos mayores des-dentados totales cuando se realizan dichos registros en la misma sesión que la impresión definitiva (AU)

Objective: To compare the anteroposterior discre-pancy measured at the level of the incisal plate of 2 methods of intermaxillary registration in the same session as the definitive impression in fully edentu-lous older adults. Materials and methods. Twenty pa-tients (n=20) with an average age of 70 years were included in the study. On each of them, intermaxillary recordings were obtained with acrylic rims trays: one with manual induction (MI) and the other with a self-induced system and single central support using a curved recording palatal surface (BYC). The models were mounted in a Whip Mix model 2240 articula-tor to which an Orthodent graph paper device was added, at the level of the incisal plate, to record the di-fferences between the positions obtained. Statistical analysis was carried out by calculating confidence intervals (95%) for mean differences and T-student for paired data (significance level: α<0.05). Results. On the mesiodistal plane at the level of the incisal plate, a statistically significant difference was found between the two recording variables (p<0.001). At this level the BYC provided more retrusive recordings than MI. Arithmetic mean (standard deviations) in mi-llimeters: 3.82 (2.1). Conclusions. The registration system with acrylic rim trays and BYC incorporated into them provides a more retrusive intermaxillary registration than MI in fully edentulous older adults when such registrations are made in the same ses-sion as the final impression.(AU)

Biotechnology in Argentine agriculture faces world-wide concentration

In the 1980s, the technical pattern of production in agriculture changed due to the increasing design of genetically modified plants. Modern biotechnology thrived on events requiring certain thresholds of scientific and technological skills as well as scale economies usually seen in developed countries. The mergers and acquisitions during the mid-1990s led to a world-wide oligopoly composed of very few agri-biotechnological mega-corporations and the literature discusses the impact of the mergers and acquisitions on the agriculture of developing countries with comparative advantages in agriculture. This paper analyzes the world-wide process of agri-biotechnological mega-corporation mergers and acquisitions as well as its impact and interrelationships with Argentine agriculture using information from primary and secondary sources. Conclusions refer to the set-backs of endogenous agri-biotechnological development due to world-wide concentration in developing countries with comparative advantage in agriculture.