Evaluation of Two Mini-Implant Lengths in the Infra-Zygomatic Crest Region (A Randomized Clinical Trial, Split-mouth Study)

orthodontic mini-implants, also known as miniscrew, implants or temporary anchorage devices, offer an effective panacea for Anchorage loss problem during fixed appliance treatments.

Indeed, Mini-implant implantation has become an essential method of controlling anchorage in the clinic and plays an important role in solving some difficult cases, where the integration of orthodontic mini-implants within fixed appliance treatments offers other advantages over conventional anchorage.

Intra-radicular micro-implants are placed in between the roots of teeth (mostly) while extra-radicular bone screws are placed away from the roots in the infra-zygomatic areas (IZC) of the maxilla and the buccal shelf areas (BS) of the mandible. Both extra-radicular bone screws and intra-radicular are classified under temporary anchorage devices used for the purpose of skeletal anchorage.

Due to the limited space, there is a risk of injury to the roots while using Intra-radicular micro-implants. Therefore, the infrazygomatic crest zone is selected as an alternative implantation site in the clinic. The infrazygomatic crest has a double-layered cortex and is close to the maxillary center of the resistance, which is suitable for implantation and provides strong anchorage.

Orthodontic bone screws can be used in almost every clinical situation that a micro-implant is used for, except that they cannot be placed inter-dental purely because of their larger dimension. They can be used for molar uprighting, segmental, and full arch distalization, intrusion of single tooth to full arch, protraction and retraction of dentition and for any other anchorage needs.