Relation between clenching strength and occlusal force distribution in primary dentition.

The aim of this study was to investigate the relation between clenching strength and occlusal force distribution in primary dentition. Twenty healthy children with normal occlusions: 11 boys and 9 girls, ages 3.2-5.8 years (avg. 4.5 years) were selected. Setting the bilateral masseter muscular activity at maximum clenching in full intercuspation as 100%, the occluding forces at 20, 40, 60, 80 and 100% clenching were recorded with pressure-sensitive sheets (Dental Prescale 50H, type R, Fuji Photo Film Co.), and the force of each primary tooth was analysed by computer (Occluzer FPD703). Occlusal force distribution was expressed as a percentage of the total occlusal force of each tooth and was compared between each clenching. There were no significant differences between various clenching strengths in the occlusal force distribution in primary dentition [one-way repeated-measures analysis of variance (ANOVA)]. Thus, the results of the present study suggest that the distribution of occluding forces on a primary dental arch had its own pattern and that the clenching strength had no effect on that pattern. These patterns may be useful in determining occlusal function in children.