Estudo das Alterações Morfológicas e Morfométricas das Cabeças da Mandíbula em Roedores Adultos após Diminuição da Dimensão Vertical de Oclusão

Resumo (EN)

The objective of the present study was to verify if the Pathological Decrease of the Vertical Dimension of Occlusion in Adult Rodents is capable to produce morphologic and/or morphometrics alterations in their heads of the jaw and in case they happen in that area would prevail. Twenty-four mice (Rattus norvegicus albinus, variety Wistar), males, adults, with medium age of 90 days and approximately 260 g of initial weight on average that you/they were divided in 3 experimental groups and of each group they were separate three animals that served as control. Wear and tear occlusals and incisals were proceeded until that if it reproduced a significant decrease of the vertical dimension of occlusion. The animals were sacrificed and they had their heads of the jaw, measured and analyzed morphometric and histological through the light microscopy, in the following intervals: 07 days after the wear and tear for the 1 st group, 14 days for the 2nd group and 28 days for the 3rd group. With the purpose of to quantify the degree of modification in the way of the surface of the heads of the jaw and to verify the area of predominance of these alterations, their heights were measured in two different angles (75th and 125th) always using the lateral image and analyzed the relationship perimeter/area of three continuations A, B and C. the analysis through the stereoscopic magnifying glass demonstrated that there were significant form alterations and size in the heads of the jaws studied in comparison with the one of the animals control and that the area that more alterations suffered during the whole experimental period was the central area, that it corresponds to the area of larger functional request during the physiologic process of the mastication. The analysis through the relationship perimeter/area of the heads of the jaws demonstrated have happened alterations in those measured in the group experimental 07 days in relation to the heads of the jaw of the mice control of the same group, that you/they show remodeling areas, recovering their dimensions starting from the group experimental 14 days and in the group 28 days the measures were equal her. The red-faced histological sheets for the technique of the hematoxilina­eosina and analyzed through the light microscopy showed great areas of bone reabsorption in images of degeneration of the head of the jaw in the group experimental 07 days, however we identified areas of bone neoformation starting from the group experimental 14 days getting to present osteoblasts rhymes in areas of intense bone remodeling, with to strong presence of bone trabeculate in the group 28 days. The pathological decrease of the vertical dimension of occlusion in mice provoked morphologic and morphometrics modifications in the studied areas of the heads of the jaw, and that after an initial period the adaptation that happened in those heads of the jaw is completed with a remodeling process that, it takes to the re-establishment of the masticatory functions.