The effect of force magnitude on extractable bone resorptive activity and cemental cratering in orthodontic tooth movement.

The delay period in the orthodontic tooth movement cycle was studied with respect to the stimulation of an extractable bone resorptive activity and the degree of tissue damage at sites of greatest pressure. Total area of cemental cratering was used as a measure of tissue damage. Both bone resorptive activity and tissue damage were found to be significantly increased with moderate and high forces, a fact which supports the suggestion that bone resorptive activity is related to tissue damage.