Simultaneous 'dual system' rehabilitation in the treatment of facial paralysis. Simultaneous dual system rehabilitation of facial paralysis involves using two independent reanimation techniques to optimize facial movement in both a quantitative and qualitative manner. These techniques involve the use of nerve grafting or crossover procedures combined with a dynamic muscle transfer. A group of 37 patients who underwent five different combinations of reanimation was analyzed. The techniques were evaluated using a standard rating scheme for judging success of reanimation procedures. The combination of a masseter muscle transfer to the lower region of the face and a cable graft of the upper facial nerve division appeared to offer excellent results in terms of independent motion of the upper and lower regions of the face and good eye closure, while allowing spontaneous mimetic function in 50% of cases. The advantages and disadvantages of the other techniques are described. The clinical situations in which these techniques have advantage over single reanimation techniques are outlined. 