Influence on force curve exerted by jaw tapping force

The purpose of this study, which made use of visual biofeedback, was to det ermine how methods of regulating jaw tapping force differed depending on th e strength of the tapping, using the force curve as an index. Nine healthy examinees were asked to make 30-35 jaw tapping movements, reproducing the d efined target tapping force as accurately as possible. We measured the dura tion of the tooth contact phase, the time to peak force, the first time der ivative of force (peak dF/dt), and the time to peak dF/dt. The results indi cated that the duration of the tooth contact phase and the time to peak for ce increased with the target value (P < 0.01). As the target rose, the peak dF/dt increased significantly (P < 0.01), but the time to peak dF/dt was n ot significant (P = 0.134). We found that the higher the target value, the greater the degree of dependency on feedback information. We also found tha t both the peak dF/dt and the time to peak dF/dt were determined for each e xaminee prior to movement.