the vertical dimension of the face with the jaws in rest relation; decrease in rest vertical dimension may or may not accompany a decrease in occlusal vertical dimension; it may occur without a decrease in occlusal vertical dimension in patients with a preponderant activity of the jaw-closing musculature, as in patients with muscular hypertenseness or in chronic gum chewers; increase in rest vertical dimension may or may not accompany an increase in occlusal vertical dimension; it sometimes occurs after the removal of remaining occlusal contacts, perhaps as a result of the removal of noxious reflex stimuli.
