Anchorage control is important for efficient orthodontic treatment. Osseointegration of implant -bone encouraged orthodontists to use implants as stationary anchorage. However, it has some defects such as root damage. This article was to explain factors significantly contributing to damage; histological changes and turnover of the damage, location-related factors（vertical position, sagittal position, placement side）, implant-related factors（material, length, diameter）, insertion-related factors（mode, direction, moment） and orthodontic-related factors（mode of loading） have positive effects on the damage. After mini-screw contacts the tooth, the majority show repair and almost complete healing within a few weeks after removal of the screw or the orthodontic force without complications.
