**3.2. Mechanical-physical stimulations**

It was reported that stimulating periodontal ligament mechanically or physically can increase alveolar bone remodeling and tooth movement accordingly. Physical methods frequently include equipment-assisted treatment methods [6] such as low-dose laser applications, electromagnetic field, direct electrical current, and vibrational applications. These methods take effect by inducing signal molecules such as receptor activator of nuclear factor-kappa B (RANK), receptor activator of nuclear factor-kappa B ligand (RANKL) pathway, mitogenactivated protein kinase (MAPK), c-fos, and nitric oxide [6, 19].

tooth movement by breaking the resistance [27]. Köle et al. applied vertical corticotomies between the roots of two adjacent teeth buccally and lingually and horizontal osteotomies subapically as to combine corticotomies buccal-lingually. They theorized that the segments which became "blocks of bone" move as a whole to achieve rapid tooth movement without devitalization in long-term monitoring. Düker et al. also reported that pulpal and periodontal tissues of the teeth which were applied orthodontic force similarly were not damaged in their

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http://dx.doi.org/10.5772/intechopen.81419

Although Köle and Düker proposed the opposite, periodontal and pulpal damages can be formed following invasive horizontal subapical osteotomies [29]. Additionally, osteotomy surgery is an invasive intervention with possible complications such as vascular and nerve damages so it is not a widely accepted method [30]. Nonetheless, Köle's studies pioneered surgery-assisted methods which accelerate tooth movement to be involved in the literature of modern orthodontics.

Köle's horizontal subapical osteotomies were changed with horizontal subapical corticotomies by Gantes et al. [31] and Suya [32] and it was stated that treatment of the cases was completed in almost 50% less period when compared to conventional methods. Gantes et al. [31] reported that overall vitality of the tooth was preserved and none of the patients had a periodontal damage that can be clinically recognized despite minimal root resorptions and gingival recession. Suya [32] asserted that corticotomy-assisted orthodontics had less root resorption and relapse risk and pain when compared to traditional treatments. In a recent study, Uzuner et al. [33] reported that corticotomy-assisted orthodontics increased the rate of tooth movement during canine retraction in 20% ratio and also relative bodily movement was

The method was introduced to orthodontic literature by Liou and Huang [34]. Initially, a distractor device which consists of canine and molar bands was applied to the patients by the researchers and following extraction of upper first premolar teeth, surgical preparation phase which consists of two vertical channels formed buccally and lingually toward canine teeth through the extraction socket and a horizontal incision on the base of the extraction socket that connects the channels was completed at the same session. Interseptal bone was not cut mesiodistally during the surgical intervention. Activation was carried out without a need for latent period different from traditional distraction method and distalization of canine teeth was completed in a short period of 3 weeks with minimal anchorage loss. None of the patients suffered from pain and minimal resorption was observed in the roots of canine teeth in the radiographies at the end of procedure. Suggesting to be used especially in orthodontic treatments with primary premolar extraction which has anterior crowded teeth, Liou and Huang [34] associate the periodontal ligament distraction with this method to the distraction which

The method was introduced by Kişnişci et al. [35] in 2002. The researchers applied a distraction device before teeth extraction as in periodontal ligament distraction method but a more

study on dogs with reference to Köle's corticotomies [28].

achieved with the corticotomy-combined treatment.

is formed in midpalatal suture during rapid maxillary expansion.

*3.3.2. Corticotomy-assisted treatments*

*3.3.3. Periodontal ligament distraction*

*3.3.4. Dentoalveolar distraction*

Low-dosage laser applications are reported to increase osteoblastic and osteoclastic activity by stimulating cellular proliferation and differentiation and accelerate orthodontic tooth movement without creating side effects on periodontal ligament [6, 20].

It is also reported that electromagnetic field applications increased levels of a group of enzyme which is responsible from regulating intracellular metabolism and cellular proliferation accordingly by influencing sodium-calcium change speed in cell membrane [21]. Increase in osteoblastic and osteoclastic activity causes an acceleration in the tooth movement. Darendeliler et al. [22] reported that static magnetic field accelerated tooth movement by shortening unproductive period when no tooth movement is observed but the side effect can be a decrease in serum calcium and slight changes in the chemistry of blood.

Applying direct electric current is also among tooth acceleration techniques, but its clinical use is asserted as not appropriate due to some complications such as application difficulty, ionic reactions that cause damages in tissues, and replacing of bone tissue with connective tissue [23].

Resonance vibration and ultrasonic vibration are also among the methods which are used to accelerate tooth movement. Resonance vibration is reported to increase release of peptide which is called RANKL within periodontal ligament and increase tooth movement rate by providing formation, function, and continuity of osteoclasts. Tooth movement can also be accelerated via ultrasonic vibration with the same mechanism but there is a risk that the heat can cause damage in the dental pulp [19].
