The mini-screw as an absolute anchorage device, are now a common method of treatment in
orthodontics with simplicity and effectiveness. It has played a significant role in the development of
teeth movement techniques and changed the treatment principles. While the inter-radicular devices are
placed in the alveolar process between or near the roots of teeth, the extra-alveolar or extra-radicular
screws are placed outside the alveolar process that supports the roots of teeth with two favourite sites:
mandibular buccal shelf and infra-zygomatic crest. However, the characteristics and usage of the extraalveolar bone screws are still of great interest to orthodontists. The objective of this article is to
synthesize evidence from the literature on the concept, characteristics, indications and usage of extraalveolar bone screws, to help orthodontists understand and apply effectively.