Myasthenia gravis is an autoimmune disease where corticoids are the basis of 
therapy. They are taken for short periods in large amounts, as well as for 
prolonged periods in medium or small doses. The authors investigated in the 
described groups the effect of corticoids on bone tissue. They provided evidence 
of a significant effect on the diffraction pattern, geometrical arrangement of 
the apatite grid and ion changes in relation to the period of corticoid 
administration without significant clinical manifestations of osteoporosis, when 
respecting therapeutic principles.