Abstract
The purpose of this study was to evaluate the characteristics of mandibular jaw movement as a unit in children.
Twenty-one subjects with normal occlusion were divided in three age groups: primary dentition group (1 boy, 3 girls), early mixed dentition group (2 boys, 5 girls), and permanent dentition group (2 men, 8 women) . Jaw movement was measured with a 6 degrees of freedom jaw tracking device.
Jaw movement of the whole mandible was simulated on a graphic terminal. The elements of translation and rotation of the mandible during lateral excursion were determined by the intermaxillary axis model.
The results obtained were as follows:
1.The kinematic condylar point could be detected in 5 children.
2.The distance of working condylar path during lateral excursion was significantly larger in children than in adults.
3.During lateral excursion the working condyle was not the center point of rotation in many children.
4.The results of the intermaxillary axis model analysis indicated that translation of the mandible in children was larger than in adults, and that rotation of the mandible in children was consistent with that of adults. The results suggested that lateral excursion in children has a large element of translation.
