Assessment of masticatory efficiency: new methods appropriate for clinical research in dental practice.

A new chewing test has been assessed in which the test food was contained in a chewable rubber bag. Six subjects chewed ten single 'unbagged' almonds and ten single 'bagged' almonds. The bagged experiments gave generally similar results to unbagged ones in terms of the particle size distribution; they also proved more acceptable to the subjects and eliminated the serious, undefinable loss of chewed particles that occurs intraorally in conventional (unbagged) tests. In this study an optical scanning method was used which provided a simple, fast measurement of individual particles.