Modern Anchorage Systems in Orthodontics

Anchorage has been a vital topic since the origin of orthodontics. In the orthodontic process, gentle, constant pressure is applied to the teeth that need to be moved against the other teeth, which serve as the anchoring unit. The anchoring teeth must be completely stable. The introduction of temporary anchorage devices to the orthodontic field has made it possible to overcome conventional anchorage and its limitations. Mini implants have widened the horizon of the orthodontic field. Skeletal anchorage has, to a large degree, replaced conventional anchorage in a situation where anchorage is considered either critical, insufficient, or likely to result in undesirable side effects such as vertical displacements generated by intermaxillary force systems. Over the last few years, anchorage control with mini-implants has acquired plenty of significance in the clinical management of orthodontic patients. The mode of anchorage facilitated by these implant systems has a unique characteristic owing to their temporary use, which results in a transient, albeit absolute anchorage. The foregoing properties, together with the recently achieved simple application of these screws, have increased their popularity, establishing them as a necessary treatment option in complex cases that would have otherwise been impossible to treat. This comprehensive review aims to present and discuss the historical view, clinical uses, benefits, and drawbacks of the mini-screw implants used to obtain a temporary anchorage for orthodontic applications. Topics to be discussed include classification, types and properties, types of screw, head, and thread, their clinical applications, sites, and placement method selection.