Masticatory ability in patients with removable dentures. A clinical study of masticatory efficiency, subjective experience of masticatory performance and dietary intake.

One of the functions of the masticatory system is to grind the food, salivate and prepare it for swallowing. Individuals who have lost many teeth or wear removable dentures, both complete and partial, find it more difficult to grind food i.e. they suffer from impaired masticatory efficiency (ME). Some of these subjects have to avoid food-stuffs which are hard and difficult to chew. This could influence the social well-being and may eventually lead to an increased risk of malnutrition. Many different methods have been used to evaluate ME. In most of them the degree to which the masticated food or test material was broken down was measured by fractionating the particles in a sieve system. However, one of the purposes of chewing the food is to enlarge the surface area to be exposed to the digestive juices. A few authors have applied this idea and have calculated ME using the summarized area of the masticated test material. This is physiologically a more correct method. ME was investigated in 19 complete denture wearers who were fitted with new dentures. The subjects were tested twice with the old dentures and 5 times with the new ones. The last test took place about 18 months after insertion of the new dentures. The test material was gelatin hardened with formalin. The breakdown of test material was calculated by fractionating it in a sieve system. ME was also evaluated in two other groups, 43 complete denture wearers, who were in need of new dentures, and 19 subjects who were in need of RPDs in the lower jaw. In these two studies ME was evaluated in two ways. Firstly the summarized area of masticated gelatin particles was calculated and used as a measure of ME. Secondly almonds were used as test material and the breakdown was calculated by fractionating in a sieve system. The subjects were tested on three occasions, before prosthetic treatment and about one and four months after insertion of the dentures. On the first and last occasions the subjective experience of masticatory performance was assessed as well as the dietary intake. The results revealed no systematic change in ME when the 19 subjects were fitted with new complete dentures and when the breakdown of the test material was evaluated by fractionating it in a sieve system.(ABSTRACT TRUNCATED AT 400 WORDS)