Crystallographic and/or topological defects in orderd structures (e.g. Crystals) have many analogies to the elementary particles of the universe. Therefore, field theoretical methods seem to be promising for a general description. In recent time the gauge field approach, so successful in the elementary particle theory, has been tried, in order to develop an elementary defect theory, or defect dynamics. Such an approach must lead us to results compatible with those older ones which were finally established in more conventional approaches. We compile such results and prove, in particular, that the often quoted dislocation-disclination theory of Anthony, deWit and Kossecka is the linearized version of the differential geometry of defects, initiated by Kondo, Bilby, Bullough and Smith. We then apply the gauge field approach to a medium with Toupin's microstructure which leads us to a generalized differential geometry capable to describe such more complex structures. Also here do appear disclinations. 1991.
