Current status of the biomechanics of extra-alveolar miniscrews

Temporary skeletal anchorage devices such as miniscrews are frequently used nowadays. Compared to miniplates, miniscrews are much less expensive and technically easier to place and remove; they are popular and can be easily placed by an orthodontist. Extra-alveolar miniscrews offer benefits compared to inter-radicular miniscrews, such as reduced risk of root damage and the lack of interference with the mesiodistal tooth movement. They are particularly useful for addressing anchorage loss issues and enabling specific tooth movements such as total arch maxillary and mandibular retraction, posterior distalization, molar protraction, molar intrusion, occlusal plane control, and midline correction. The present paper discusses the current biomechanics principles related to the use of extra-alveolar miniscrews placed in the infrazygomatic and mandibular buccal shelf.