Abstract
The purpose of this study was to clarify the change of chewing movement in the process of mastication. The food sample used in this study was jelly, The texture of which getting to changes as mastication progresses. The subjects were divided into two groups according to dental age: the primary dentition group (3 boys,3 girls) and the permanent dentition group (7 women). The reference point was the lower incisal point. All the chewing cycles were divided into the early, middle and late period. Evaluation of the chewing movement according to the masticatory process was made using the following parameters; terminal position, maximum opening distance, maximum lateral distance, duration of chewing cycle, opening phase and closing phase. These aspects were compared between the two groups.
The results were as follows:
1. The terminal position became closer to the intercuspal position as mastication progressed in both children and adults.
2. The maximum opening distance became shorter as mastication progressed in both children and adults.
3. The maximum lateral distance became smaller as mastication progressed in adults, while there was no such trend in children.
4. The duration of the chewing cycle and the closing phase became shorter in children, while there was no change with the chewing rythm in adults as mastication progressed.
