Various Applications of Mid-palatal Absolute Anchorage System Using a Safe, Multifunctional and Solid Screw in Lingual Orthodontic Treatment

抄録

　The posterior region of the mid-palatal suture is an appropriate location for placing screw implants. Using safe, multifunctional and solid (SMS) screws, a skeletal anchorage system known as the mid-palatal absolute anchorage system (MAAS) has been developed to withstand more substantial orthodontic forces. In this article, MAAS is introduced and various clinical applications of MAAS in lingual orthodontic treatment are described. MAAS plays a role not only in direct skeletal anchorage (e.g. posterior intrusion, total intrusion, total distalization, anterior retraction and unilateral constriction), but also as indirect skeletal anchorage (e.g. molar distalization). In conjunction with lever arms, MAAS works as an absolute anchorage instrument, with which full control over the axial inclinations of the anterior teeth during retraction is possible. In addition, MAAS drives orthodontic forces not only with respect to individual tooth movements, but also where required to move whole dental arches in any direction with the assistance of a diverse array of power arm configurations and modified lingual arches. MAAS is versatile enough to allow the provision of orthodontic forces in any required direction and can be effectively used as an absolute anchorage device in lingual orthodontic treatment.