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?