Food consistency and bite size as regulators of jaw movement during feeding in the cat.

Abstract
The movements of the cat mandible were recorded by cineradiography while the animals were fed on foods of varying physical characteristics. Each of the jaw-movement cycles, making up a sequence from food ingestion to deglutition, was divided into 4 phases on the basis of regularly occurring and sequential velocity changes: fast close (FC), slow close (SC), slow open (SO), and fast open (FO). A basic jaw-movement profile with a long SO phase, typified by lapping, was associated with a food-transport mechanism within the mouth. The FO/FC complex was an additional component elicited by the presence of solid or semisolid food in the mouth. The separate class of chewing cycles (those having short SO phases and a large FO/FC complex), which occurred only when solid food was in the region of the cheek teeth, may result from the operation of a set of reflexes arising largely from the stimulation of mucosal afferents in that part of the mouth.