The prosthetic treatment of edentulous glossectomy patients is very difficut. The tongue defect results in oral dysfunction and affects the stability of the mandibular denture. The appropriate denture form and occlusion can be established by using the modified functional impression technique. Through the use of x-ray television and an image-processing system in clinical experiments, it was shown that a wide buccolingual table, an occlusal table height matched to that of the tongue body, and close adherence of the tongue and the lingual flange are effective means of preventing food from dropping to the oral floor, keeping the food on the occlusal table, and crushing the food.