A 57-year-old patient complains of tooth mobility, inability to eat. Objectively: the lower 35, 36, 37, 38, 44, 45, 46 and 48 teeth are missing; the 31,32,33,34, 41, 42, 43, 47 teeth exhibit II grade mobility, their clinical crowns are low, tooth equator is not pronounced. What is the optimal denture construction in this case?