The important causes of tooth wear were abrasion, erosion and attrition. Although there were occlusal wear in all persons, the severity of tooth wear were very different from person to person and area to area. The tooth contact patterns during chewing could be related with occlusal wear. There were two types of chewing patterns. One was chopping chewing pattern like carnivorous animal and the other was grinding chewing pattern like hernivorous animal. The purpose of this research was to study the relationship among tooth wear, chewing patterns and incisal guidances.
90 dental student, who had normal mandibular movements, normal chewing function and no occlusal restorations, had recording of chewing movements with Sapon Visitrainer.
12 students of chopping chewing group and 12 students of grinding chewing group were selected. Alginate impression were taken and stone model of each student were made. Ordinal scale was used to evaluate the degree of tooth wear for chopping chewing group and grinding chewing group. Incisal guidances of each student were measured and compared to chewing pattern and tooth wear. t-test was to used to evaluate the differnece of tooth wear between two groups. The correlation between incisal guidance and tooth wear was statisticaly evaluated with SPSS. The conclusions were following ;
1. The anterior teeth showed greater tooth wear than posteriror teeth in both groups.(P<0.01).
2. The chopping chewing group showed less tooth wear in anterior teeth, upper teeth, lower teeth, and all teeth than grinding chewing group. (P<0.05)
3. Incisal guidance of the chopping chewing group were not different from that of the grinding chewing group.(P>0.05)
4. The incisal guidance was not statistically related with tooth wear.(P>0.05)
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