Purpose: The purpose of this study was to evaluate the duration of the masticatory cycles in complete denture wears after reducing the Occlusal vertical dimension.

Materials and Methods: Twenty completely edentulous subjects, 4 females and 16 males, their ages were between (40-70) years precipitated in this study. One upper and two lower complete dentures were fabricated for each subject, the first set of upper and lower complete dentures were made with a suitable OVD, while the second set of complete dentures were made with reduced OVD (about 3 mm). The Duration of twenty masticatory circle was performed two months after the patient delivered the first complete denture. The same procedures were repeated for the second set of complete denture wears.

Results: The mean of The Duration of twenty masticatory cycles in the patients who wear complete dentures with suitable OVD was 11.22 seconds, while for the patients who wear complete dentures with reduced OVD was 11.99 seconds.

Conclusions: The value of the Duration of twenty masticatory cycles in dentures with an appropriate OVD was smaller than that of the decreased OVD in the research sample. There are statistically significant differences in the mean of the Duration of twenty masticatory cycles between the two groups at the confidence level of 95%.