The development and reproducibility of maximal clenching forces developed between two antagonistic teeth on a gnathodyamometer were examined. All the occlusal surface of the two teeth was used by adapting acrylic bite blocks on the dynamometer. It appeared that the maximal clenching force is a reproducible value. Itwas also noted that the developed force increases progressively when a maximal clenching effort is exerted successively every fiften seconds, even after a pause of five minutes. After about ten clenching efforts the developed force became stabilized. However, when the subject paused for ten minutes, the clenching force he developed immediately afterwards, returned to the level at the beginning of the experiment.