**3.3. Surgical-assisted techniques**

The most clinically used and predictable option with stable results among the techniques which accelerate tooth movement is the surgical-assisted technique; it is evaluated as a costly invasive method [6]. It is based on the idea that rapid tooth movement can be achieved by increasing the biological response which is formed in periodontal ligament and alveolar bone. Creating an injury in the bone is a potential physical mechanism which provides rapid tissue recovery. Higher regional tissue response during this tissue remodeling/regeneration period is called as regional acceleratory phenomenon (RAP) [24]. Regional acceleratory phenomenon is a complex physiological case in which initially osteoclastic activity and secondly bone density is decreased followed by a rapid osteoblastic activity and a remodeling process. Orthodontic tooth movement acceleration is provided via the increase in cytokine activity around the teeth and decrease in cortical bone resistance and formation of hyalinization tissue by activation of this recovery mechanisms [25]. The advantages of the dentoalveolar surgical intervention in orthodontic treatment of adult patients are reported as: (a) less treatment time, (b) avoidance of potential periodontal complications, (c) favorable direction of growth, and (d) extensive envelope of the tooth movement [26].
