RÉSUMÉ
During orthodontic treatment the teeth are exposed to forces and moments, and these acting forces always generate reciprocal forces of the same magnitude but opposite in direction which follows Newton’s third law. To avoid unwanted tooth movements and maintain treatment success, these reciprocal forces must be diverted effectively. In orthodontic treatment, anchorage loss is a potential side effect of orthodontic mechanotherapy and one of the major causes of unsuccessful results. Its cause has been described as a multifactorial response in relation to the extraction site, appliance type, age, crowding, and overjet.Therefore, clinicians throughout the years have made an effort to find biomechanical solutions to control anchorage. The purpose of this article is to review the basics of anchorage and the anchorage planning in different appliance systems.