The reproducibility of movement parameters of the empty open-close-clench cycle in man and their dependency on the frequency of movements

Summary The reproducibility of the empty open‐close‐clench cycle has been investigated. Four subjects were asked three times to perform thirty empty open‐close‐clench movements at each frequency of ½, 1 and 2 cycles s−1. To describe such a series of thirty movements a set of nine parameters were selected. By reference to these parameters it was found that the subjects were not always able to exactly reproduce a series of thirty movements at a repeat test. The movement‐parameters strongly depended on the frequency of the movements. On increasing the frequency the durations of time in which a movement cycle was divided decreased, while the maximum jaw speeds during opening and closing and the jaw speed just before tooth contact increased. The parameter values chosen to describe the smoothness of the movements performed, indicated that the smoother movements were executed at the higher frequencies.