Relationship between Development of Occlusal Contact and Stomatognathic Function in Children

Abstract

The purpose of this study was to clarify the relationship between the development of occlusal contact and stomatognathic functions in children at different dental age stages.
The subjects were 10 children with normal occlusion. Five children were at Hellman's dental age IIIA (mean age 9.0 years) and 5 children were at IIIC (mean age 12.4 years). All of the subjects had their jaw movement measured at six degrees of freedom using a jaw tracking device and the three dimensional morphology of tooth surface using three dimensional contact digitizer. The data for the jaw movement and the tooth surface morphology corresponded. The occlusal contacts during lateral excursion were analyzed and visualized on a terminal graphic.
The results were as follows:
1. The sagittal angles of the incisal and condylar path during jaw movement increased, and the distance of the working condylar path during lateral excursion significantly decreased.
2. The subjects at stage IIIA had two patterns of occlusal contact during lateral excursion. One had occlusal contacts at the permanent lateral incisor and primary canine, and the other had them at the every tooth on the working side. The subjects at stage IIIC had an occlusal contact pattern which showed contacts at the canine and premolars on the working side.
3. Although subjects at stage HI A with the right-and-left difference in the distance of the working condylar path and occlusal contact area on the working side during lateral excursion was larger than that of subjects at stage IIIC.
These results suggest that permanent teeth, especially canines, play a role in developmental change of condylar movement during lateral excursion.