Intermittent orthodontic force is applied only when the appliance is in place and stops immediately upon its removal. This means the force does not gradually diminish but instead declines abruptly to zero. This characteristic impacts the biological response, as the periodontal ligament and bone remodeling processes pause during the intervals without force. Continuous or gradual force application differs by maintaining some stimulus even when the appliance is inactive. Understanding this helps in planning timing and appliance wear for effective tooth movement.

Reference: Contemporary Orthodontics, William R. Proffit, 6th Edition.