**4. Micro-osteoperforations**

Orthodontic tooth movement is a biological response which is created by an external force that will prevent the dentofacial complex to be in physiological balance [13]. Orthodontic force creates an aseptic inflammatory response in periodontal tissues. An increase on vascular permeability and cellular infiltration of leucocytes was reported in the early period of orthodontic tooth movement [47]. Along with native cells such as osteoblasts and fibroblasts, migrated immune cells produce inflammatory cytokines that include chemotactic factors, growth factor, monocyte-derived factor, lymphocyte, and colony-stimulating factors [48, 49]. The gingival crevicular fluid of moving teeth includes tumor necrosis factor-α (TNFα), interleukin-1 (IL-1), IL-2, IL-3, IL-6, IL-8, osteoclast differentiation factor, and interferon-γ (IFNγ) [48, 50].

release of inflammatory cytokines minimizing these disadvantages was developed (**Figure 1**). Micro-osteoperforation is an up-to-date procedure which is promoted as an auxiliary dentoalveolar procedure which can accelerate tooth movement via minimum surgical interventions. In their animal study in 2010, Teixeira et al. [25] classified 48 rats, which were applied experimental orthodontic tooth movement, into four groups as one group with only orthodontic forces, a group via application of soft tissue flaps together with orthodontic force, a group that was applied 3 small perforations on cortical plate with soft tissue flaps together and orthodontic force and a control group. The researchers stated that they formed the microperforations in the cortical bone by using a round bur and handpiece. It was observed that at the end of experimental tooth movement period, release of 37 out of the 92 cytokines increased in all experimental groups and 21 of them were at the maximum level in the group which was applied perforation. In addition to that, light and fluorescent microscopy, microcomputed tomography, and immunohistochemistry examinations, which were carried at the end of the experiment, represented a significant increase in osteoclast number which accompanied by generalized osteoporosis and orthodontic tooth rate besides bone remodeling activity [25]. Similar to previous studies, researchers also demonstrated that the increase in bone remodeling was not limited around the loaded teeth but also involved the periodontal structures of the adjacent teeth. The researchers, who argued that the observed effects of osteoperforations on tooth movement can be related to loss in bone structure rather than release of increased inflammatory cytokine, stated that perforations were applied in the smallest amount and number possible and the remaining cortical bone was healthy in order to minimize this possibility. These findings also represent that the perforations that will be applied in order to accelerate tooth movement rate are not necessarily be adjacent to the moved teeth. Stating that inflammation can cause negative effects on periodontium and tooth structure when it is uncontrolled because it is a double-sided injury, it is also reported that applying micro-osteoperforations instead of some surgical interventions such as corticotomy,

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which are applied for acceleration of tooth movement, can minimize the side effects.

**Figure 1.** Micro-osteoperforations on cortical bone increase bone remodeling and tooth movement rate by stimulating

release of inflammatory cytokines.

Orthodontic tooth movement rate is basically found associated with the rate of bone resorption which is controlled by osteoclast activity [51]. Therefore, any factors which effect activities of osteoclast precursor cells and their transformations into osteoclasts can be assumed to have significant effects on orthodontic tooth movement. There are a lot of researches that report the increase in the activity of inflammatory markers such as chemokines and cytokines as a response to orthodontic forces [5, 25]. It is reported that several cytokines which play role in osteoclast formation and activity such as TNFα, IL-1, and IL-6 are found in gingival crevicular fluid during orthodontic tooth movement [25]. Although the roles of chemokines and cytokines during orthodontic treatment are not clearly known, they are valued as essential mediators for orthodontic tooth movement in terms of their significant roles on differentiation and activity of osteoclast cells [52–54]. Significant decrease on orthodontic tooth movement rate within the studies in which the effects of these markers are blocked via different techniques such as anti-inflammatory medication or genetic manipulation can be accepted as a proof that these factors are extremely efficient on orthodontic tooth movement rate [55–57]. Previous studies represent that surgical interventions which cause minor bone traumas increase inflammatory cytokines, bone remodeling, and orthodontic tooth movement acceleration together with regional bone density [24, 58]. Surgery-assisted techniques which are applied in order to accelerate orthodontic tooth movement should be studied under subtitles such as corticotomy and osteotomy techniques, dental distraction technique, perisegmental corticotomy, and piezoincision. Corticotomy-assisted orthodontic treatment increases bone remodeling which accelerates recovery and repair mechanisms and tooth movement rate accordingly by creating a mechanical trauma in cortical bone [59]. Although corticotomyassisted orthodontic treatment was reported to be an efficient method in accelerating tooth movement, the significance of removing flaps is also stated to cause important postoperative complications [60]. Piezoincision technique, which is a minimally invasive technique that includes piezoelectric incisions without removing flaps, was developed in order to overcome these disadvantages [43]. Piezoincision is known to be an effective method for acceleration of tooth movement but it was reported to have high risks of damaging tooth roots [18]. Surgeryassisted techniques are invasive with disadvantages such as bone loss, postoperative pain, edema and infection, avascular necrosis besides low acceptance rates by the patients [37, 40]. Based on this, the hypothesis that small osteoperforations on cortical bone without removing flaps will increase bone remodeling and tooth movement rate accordingly by stimulating release of inflammatory cytokines minimizing these disadvantages was developed (**Figure 1**). Micro-osteoperforation is an up-to-date procedure which is promoted as an auxiliary dentoalveolar procedure which can accelerate tooth movement via minimum surgical interventions.

**4. Micro-osteoperforations**

80 Current Approaches in Orthodontics

Orthodontic tooth movement is a biological response which is created by an external force that will prevent the dentofacial complex to be in physiological balance [13]. Orthodontic force creates an aseptic inflammatory response in periodontal tissues. An increase on vascular permeability and cellular infiltration of leucocytes was reported in the early period of orthodontic tooth movement [47]. Along with native cells such as osteoblasts and fibroblasts, migrated immune cells produce inflammatory cytokines that include chemotactic factors, growth factor, monocyte-derived factor, lymphocyte, and colony-stimulating factors [48, 49]. The gingival crevicular fluid of moving teeth includes tumor necrosis factor-α (TNFα), interleukin-1 (IL-1),

IL-2, IL-3, IL-6, IL-8, osteoclast differentiation factor, and interferon-γ (IFNγ) [48, 50].

Orthodontic tooth movement rate is basically found associated with the rate of bone resorption which is controlled by osteoclast activity [51]. Therefore, any factors which effect activities of osteoclast precursor cells and their transformations into osteoclasts can be assumed to have significant effects on orthodontic tooth movement. There are a lot of researches that report the increase in the activity of inflammatory markers such as chemokines and cytokines as a response to orthodontic forces [5, 25]. It is reported that several cytokines which play role in osteoclast formation and activity such as TNFα, IL-1, and IL-6 are found in gingival crevicular fluid during orthodontic tooth movement [25]. Although the roles of chemokines and cytokines during orthodontic treatment are not clearly known, they are valued as essential mediators for orthodontic tooth movement in terms of their significant roles on differentiation and activity of osteoclast cells [52–54]. Significant decrease on orthodontic tooth movement rate within the studies in which the effects of these markers are blocked via different techniques such as anti-inflammatory medication or genetic manipulation can be accepted as a proof that these factors are extremely efficient on orthodontic tooth movement rate [55–57]. Previous studies represent that surgical interventions which cause minor bone traumas increase inflammatory cytokines, bone remodeling, and orthodontic tooth movement acceleration together with regional bone density [24, 58]. Surgery-assisted techniques which are applied in order to accelerate orthodontic tooth movement should be studied under subtitles such as corticotomy and osteotomy techniques, dental distraction technique, perisegmental corticotomy, and piezoincision. Corticotomy-assisted orthodontic treatment increases bone remodeling which accelerates recovery and repair mechanisms and tooth movement rate accordingly by creating a mechanical trauma in cortical bone [59]. Although corticotomyassisted orthodontic treatment was reported to be an efficient method in accelerating tooth movement, the significance of removing flaps is also stated to cause important postoperative complications [60]. Piezoincision technique, which is a minimally invasive technique that includes piezoelectric incisions without removing flaps, was developed in order to overcome these disadvantages [43]. Piezoincision is known to be an effective method for acceleration of tooth movement but it was reported to have high risks of damaging tooth roots [18]. Surgeryassisted techniques are invasive with disadvantages such as bone loss, postoperative pain, edema and infection, avascular necrosis besides low acceptance rates by the patients [37, 40]. Based on this, the hypothesis that small osteoperforations on cortical bone without removing flaps will increase bone remodeling and tooth movement rate accordingly by stimulating In their animal study in 2010, Teixeira et al. [25] classified 48 rats, which were applied experimental orthodontic tooth movement, into four groups as one group with only orthodontic forces, a group via application of soft tissue flaps together with orthodontic force, a group that was applied 3 small perforations on cortical plate with soft tissue flaps together and orthodontic force and a control group. The researchers stated that they formed the microperforations in the cortical bone by using a round bur and handpiece. It was observed that at the end of experimental tooth movement period, release of 37 out of the 92 cytokines increased in all experimental groups and 21 of them were at the maximum level in the group which was applied perforation. In addition to that, light and fluorescent microscopy, microcomputed tomography, and immunohistochemistry examinations, which were carried at the end of the experiment, represented a significant increase in osteoclast number which accompanied by generalized osteoporosis and orthodontic tooth rate besides bone remodeling activity [25]. Similar to previous studies, researchers also demonstrated that the increase in bone remodeling was not limited around the loaded teeth but also involved the periodontal structures of the adjacent teeth. The researchers, who argued that the observed effects of osteoperforations on tooth movement can be related to loss in bone structure rather than release of increased inflammatory cytokine, stated that perforations were applied in the smallest amount and number possible and the remaining cortical bone was healthy in order to minimize this possibility. These findings also represent that the perforations that will be applied in order to accelerate tooth movement rate are not necessarily be adjacent to the moved teeth. Stating that inflammation can cause negative effects on periodontium and tooth structure when it is uncontrolled because it is a double-sided injury, it is also reported that applying micro-osteoperforations instead of some surgical interventions such as corticotomy, which are applied for acceleration of tooth movement, can minimize the side effects.

**Figure 1.** Micro-osteoperforations on cortical bone increase bone remodeling and tooth movement rate by stimulating release of inflammatory cytokines.

Tsai et al. [11] applied both micro-osteoperforations and corticision without removing flaps different from the previous studies and evaluated the differences between the procedures in their animal study which was carried out to evaluate the effects of micro-osteoperforations and corticisions on orthodontic tooth movement rate. It was stated that bone and bone mineral densities were significantly decreased when compared to control group and tooth movement rate was increased in both groups without any significant difference. The rise in tooth movement rate in both groups in this study is smaller than the previous studies. The researchers, who stated that there might be a direct proportion between trauma amount and remodeling rate, reported that the difference was resulted from the smaller amount of the trauma as the flap was not removed.

without removing flaps via a piezoelectric device), and even tooth extractions will increase the release of inflammatory markers and bone remodeling by creating injuries similar to micro-osteoperforations on alveolar bone effecting the rate of tooth movement accordingly [5]. Unfortunately, increase of inflammatory marker release cannot continue for a long period of time and a decrease in cytokine activity is observed regardless of the severity of the trauma after 2–3 months [4] which reveals the necessity for repeating the procedure during orthodontic treatment. Therefore, the extraction is suggested to be applied at the same time with major tooth movement for the patients whose tooth is planned to be extracted. There will not be a need for micro-osteoperforation requirement to accelerate tooth movement process as remodeling will speed up. In other words, it would be appropriate to prefer micro-osteoperforations in the treatments without tooth extraction or when extraction is carried out long after the orthodontic treatment because its effects are similar to tooth extraction. It is considered that as the level of trauma increases, inflammatory response will also rise. The rise on tooth movement rate when micro-osteoperforation number is increased can be shown as a proof. It was stated that regional acceleratory phenomenon (RAP) took effect in 1 or 2 days following the surgical intervention and reached its maximum level in 1 or 2 months [9]. Aboul-Ela et al. [59], Al-Naoum et al. [62], and Leethanakul et al. [63] reported that tooth movement speed was high during 2 months following the creation of traumas in cortical layers but it gradually decreased in this period. Alikhani et al. also stated that cytokine activity decreased after 2 months following micro-osteoperforation so they proposed that the procedure shall be repeated after a month break [4]. Micro-osteoperforations are repeatable which can be considered as an advantage because application time can affect the results in all surgically assisted procedures. On the other hand, there is not a clear information on how frequently micro-osteoperforations can be

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83

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applied in order to achieve an optimum acceleration in tooth movement rate.

tion side, more tooth movement was seen.

In a recent thesis study in Akdeniz University, Faculty of Dentistry, Department of Orthodontics (Antalya, Turkey), efficiency of micro-osteoperforations on molar distalization rate with cervical headgear was evaluated on 3D digital models [64]. About 17 patients whose molar relations were bilateral class II (minimum teeth to teeth) with class I skeletal anomalies or normal or low vertical growth pattern were included in the study which is regarded as the first study to evaluate the efficiency of micro-osteoperforations on molar distalization. Propel device (Ossining, NY) was used to form three micro-osteoperforations—one mesially and two distally—of 1.5 diameter and 5 mm depth on a random molar teeth, in the session where distalization was initiated with cervical headgears in the split-mouth designed study. Microosteoperforations were renewed at least twice during the distalization period every 8 weeks in each sample. The procedure continued until class I relationship was achieved on the side where tooth movement was considered to be slower. Studies were carried out on 3D digital models which were taken just before and after molar distalization in order to compare molar distalization rate and tilt and rotation rate in molar teeth. While no significant difference was observed between tilting and rotation rates, it was concluded that on the micro-osteoperfora-

Lee et al. [65], who stated that in the studies which evaluated the efficiency of microosteoperforations on orthodontic tooth movement, micro-osteoperforations were generally applied on healthy alveolar bone, planned a study considering that the effects of

In 2016, Cheung et al. [12] published a study which evaluated the effectiveness of microosteoperforations. Mini-implants were used in order to form micro-osteoperforations different from the previous animal studies and the existence of external apical root resorption was evaluated following the procedure. Similar to previous studies, it was observed that there was a decrease on the density and volume of the bone surrounding moved molar teeth compared with the control side besides the acceleration of orthodontics tooth movement on the side where micro-osteoperforations were applied in the split mouth design study with six rats. Histological examinations also showed that new bone formation increased as well as osteoclast numbers on the side with micro-osteoperforations. This is a proof of the existence of osteoclasts-osteoblast coupling formation with decortication. Despite the fact that resorption and new bone formation were represented together, bone fraction volume and bone mineral density was decreased, which shows that resorption was more than new bone formation during tooth movement period. Contrary to conventional theories which assert osteoclast activity is limited to pressure area, the recent studies show that periodontium was remodeled as a single unit [61]. This study also shows that osteoclast rate in all alveolar bone surrounding the moving teeth is clearly on the pressure areas.

Alikhani et al. [5] designed a clinical trial to evaluate tooth movement with or without microosteoperforations in order to investigate whether this phenomenon occurs in human or not. They called the technique of creating micro-osteoperforations in the bone as "alveocentesis." In their study, 20 adults were divided into 2 groups as control and experimental groups. Microosteoperforations were applied in the experimental group on one side of the maxilla using a disposable micro-osteoperforation device designed for this purpose by Propel Orthodontics (Ossining NY) and the control group did not receive any micro-osteoperforations. Following 28 days of canine retraction period, amount of the tooth movement was measured and also the activity of inflammatory mediators was determined in gingival crevicular fluid with an antibody-based protein assay. Additionally, the presence of pain or discomfort was evaluated with a numeric rating scale. Results of this first clinical trial about micro-osteoperforations in the literature reported significant increase in the levels of inflammatory markers and also 2.3 times rise in the rate of tooth movement with micro-osteoperforations. However, significant pain or discomfort during or after the procedure was not reported by the patients; also, any other complications were not observed.

It was stated that orthognathic surgery, corticotomies (applying several incisions and perforations with removing flaps), piezoincision (creating injury on the bone with small incisions without removing flaps via a piezoelectric device), and even tooth extractions will increase the release of inflammatory markers and bone remodeling by creating injuries similar to micro-osteoperforations on alveolar bone effecting the rate of tooth movement accordingly [5]. Unfortunately, increase of inflammatory marker release cannot continue for a long period of time and a decrease in cytokine activity is observed regardless of the severity of the trauma after 2–3 months [4] which reveals the necessity for repeating the procedure during orthodontic treatment. Therefore, the extraction is suggested to be applied at the same time with major tooth movement for the patients whose tooth is planned to be extracted. There will not be a need for micro-osteoperforation requirement to accelerate tooth movement process as remodeling will speed up. In other words, it would be appropriate to prefer micro-osteoperforations in the treatments without tooth extraction or when extraction is carried out long after the orthodontic treatment because its effects are similar to tooth extraction. It is considered that as the level of trauma increases, inflammatory response will also rise. The rise on tooth movement rate when micro-osteoperforation number is increased can be shown as a proof. It was stated that regional acceleratory phenomenon (RAP) took effect in 1 or 2 days following the surgical intervention and reached its maximum level in 1 or 2 months [9]. Aboul-Ela et al. [59], Al-Naoum et al. [62], and Leethanakul et al. [63] reported that tooth movement speed was high during 2 months following the creation of traumas in cortical layers but it gradually decreased in this period. Alikhani et al. also stated that cytokine activity decreased after 2 months following micro-osteoperforation so they proposed that the procedure shall be repeated after a month break [4]. Micro-osteoperforations are repeatable which can be considered as an advantage because application time can affect the results in all surgically assisted procedures. On the other hand, there is not a clear information on how frequently micro-osteoperforations can be applied in order to achieve an optimum acceleration in tooth movement rate.

Tsai et al. [11] applied both micro-osteoperforations and corticision without removing flaps different from the previous studies and evaluated the differences between the procedures in their animal study which was carried out to evaluate the effects of micro-osteoperforations and corticisions on orthodontic tooth movement rate. It was stated that bone and bone mineral densities were significantly decreased when compared to control group and tooth movement rate was increased in both groups without any significant difference. The rise in tooth movement rate in both groups in this study is smaller than the previous studies. The researchers, who stated that there might be a direct proportion between trauma amount and remodeling rate, reported that the difference was resulted from the smaller amount of the trauma as the flap was not removed.

In 2016, Cheung et al. [12] published a study which evaluated the effectiveness of microosteoperforations. Mini-implants were used in order to form micro-osteoperforations different from the previous animal studies and the existence of external apical root resorption was evaluated following the procedure. Similar to previous studies, it was observed that there was a decrease on the density and volume of the bone surrounding moved molar teeth compared with the control side besides the acceleration of orthodontics tooth movement on the side where micro-osteoperforations were applied in the split mouth design study with six rats. Histological examinations also showed that new bone formation increased as well as osteoclast numbers on the side with micro-osteoperforations. This is a proof of the existence of osteoclasts-osteoblast coupling formation with decortication. Despite the fact that resorption and new bone formation were represented together, bone fraction volume and bone mineral density was decreased, which shows that resorption was more than new bone formation during tooth movement period. Contrary to conventional theories which assert osteoclast activity is limited to pressure area, the recent studies show that periodontium was remodeled as a single unit [61]. This study also shows that osteoclast rate in all alveolar bone surrounding the

Alikhani et al. [5] designed a clinical trial to evaluate tooth movement with or without microosteoperforations in order to investigate whether this phenomenon occurs in human or not. They called the technique of creating micro-osteoperforations in the bone as "alveocentesis." In their study, 20 adults were divided into 2 groups as control and experimental groups. Microosteoperforations were applied in the experimental group on one side of the maxilla using a disposable micro-osteoperforation device designed for this purpose by Propel Orthodontics (Ossining NY) and the control group did not receive any micro-osteoperforations. Following 28 days of canine retraction period, amount of the tooth movement was measured and also the activity of inflammatory mediators was determined in gingival crevicular fluid with an antibody-based protein assay. Additionally, the presence of pain or discomfort was evaluated with a numeric rating scale. Results of this first clinical trial about micro-osteoperforations in the literature reported significant increase in the levels of inflammatory markers and also 2.3 times rise in the rate of tooth movement with micro-osteoperforations. However, significant pain or discomfort during or after the procedure was not reported by the patients; also, any

It was stated that orthognathic surgery, corticotomies (applying several incisions and perforations with removing flaps), piezoincision (creating injury on the bone with small incisions

moving teeth is clearly on the pressure areas.

82 Current Approaches in Orthodontics

other complications were not observed.

In a recent thesis study in Akdeniz University, Faculty of Dentistry, Department of Orthodontics (Antalya, Turkey), efficiency of micro-osteoperforations on molar distalization rate with cervical headgear was evaluated on 3D digital models [64]. About 17 patients whose molar relations were bilateral class II (minimum teeth to teeth) with class I skeletal anomalies or normal or low vertical growth pattern were included in the study which is regarded as the first study to evaluate the efficiency of micro-osteoperforations on molar distalization. Propel device (Ossining, NY) was used to form three micro-osteoperforations—one mesially and two distally—of 1.5 diameter and 5 mm depth on a random molar teeth, in the session where distalization was initiated with cervical headgears in the split-mouth designed study. Microosteoperforations were renewed at least twice during the distalization period every 8 weeks in each sample. The procedure continued until class I relationship was achieved on the side where tooth movement was considered to be slower. Studies were carried out on 3D digital models which were taken just before and after molar distalization in order to compare molar distalization rate and tilt and rotation rate in molar teeth. While no significant difference was observed between tilting and rotation rates, it was concluded that on the micro-osteoperforation side, more tooth movement was seen.

Lee et al. [65], who stated that in the studies which evaluated the efficiency of microosteoperforations on orthodontic tooth movement, micro-osteoperforations were generally applied on healthy alveolar bone, planned a study considering that the effects of bone remodeling process that was activated by applying orthodontic tooth movement and micro-osteoperforations on the atrophic ridge could be different. The researchers, who created atrophic alveolar ridge model on eight beagle dogs, evaluated tooth movement rates and atrophic alveolar ridge area on the sides with and without osteoperforations in their study which they planned via split mouth design. Micro-CT based histomorphometry analysis similar to the previous studies suggested that osteoperforations accelerated tooth movement with a decrease in bone density without any differences in atrophic ridge volume. This up-to-date finding can be evaluated as an indicator that the efficiency of micro-osteoperforations on bone remodeling is more related to resorption mechanism and osteoclast activation.

form MOPs has not included in routine clinical use yet. Thus, mini-implants are considered more advantageous than other methods as they are included in clinical routine and frequently used by orthodontists for different purposes and easily tolerated by the patients. On the other hand, in the literature, there are limited studies in which mini-implant-facilitated micro-osteoperforations are carried out with human. Aksakalli et al. [66] applied three microosteoperforations distal to the canine teeth with miniscrews just before canine distalization period. In their case report, they reported that MOP method with miniscrews accelerated canine distalization in their 14-year-old male patient with class II malocclusion by almost 1.5-fold and also without harmful effects on root and periodontal structures. On the contrary, Alkebsi et al. [67] could not find any differences of anchorage loss, canine rotation, and tipping between the MOP and control sides in their randomized controlled clinical trial where they investigated the effectiveness of miniscrew-facilitated MOPs on the rate of canine

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All of the methods are applied without a need for additional periodontal surgeries which is considered as a significant advantage but additional clinical studies are required in order to evaluate the efficiency of each technique and their advantages and disadvantages over each

When micro-osteoperforations are compared with several surgical techniques, which are proved to accelerate tooth movement, they are considered as more advantageous because they are less invasive with no need for removing flaps eliminating possible side effects of the surgery [4, 5]. Additionally, all techniques which make use of micro-osteoperforation do not include an invasive surgical procedure represent that they are easily applicable in the clinics by the orthodontists and can be added to clinical routine. Patients did not report any pain or discomfort in the clinical studies with micro-osteoperforations which shows that it is easily accepted and tolerated by the patients who are under orthodontic treatment [5, 64]. These advantages also enable the micro-osteoperforations to be periodically repeated until the desired results are achieved [4, 64].

There is a limited number of studies that evaluate patients' pain and discomfort levels among the clinical studies in which micro-osteoperforations are applied. Alikhani et al. [5] asked their patients to scale their pain and discomfort levels via a numeric rating scale on the day they replaced the device, the day they began canine distalization, 24 h, 7th and 28th days after canine distalization in their study in which they evaluated the effect of micro-osteoperforations on canine distalization. In this scale, which is reported as having high credibility, "0" presents no pain, while "10" stands for the existence of the worst pain. Data analyses showed that the patients had the most pain in 24 h following canine distalization but no significant difference was observed between experimental and control groups. The patients defined a slight and resistible pain on the micro-osteoperforation side which does not require taking painkillers but no statically significant difference was found. The similar feedbacks were taken in Boz's thesis study in 2018 concluding that micro-osteoperforations did not cause a

**4.2. Advantages of micro-osteoperforation over other surgical techniques**

**4.3. The relation of micro-osteoperforations with pain and root resorption**

distalization.

other in detail.

In the literature, there is a limited number of studies which evaluate the effects of microosteoperforations on tooth movement in human. Current studies indicate that microosteoperforation is a safe method that can accelerate tooth movement but it must be taken into consideration that several factors such as occlusal relations, movement type, applied mechanics, age and gender of the patient, oral hygiene, periodontal illnesses, alveolar bone loss, systemic diseases, and medication use effect tooth movement rate in human. Therefore, the efficiency of micro-osteoperforations must be evaluated with long-term studies in which study groups are standardized as much as possible considering these variable where different tooth movement types (distalization, intrusion, eruption of impacted tooth, etc.) and mechanics are applied containing more sample numbers.
