Dental – Velocity of tooth movement

Angle Orthod. 2015 Jul 1. [Epub ahead of print]

Evaluation of the use of low-level laser therapy in pain control in orthodontic patients: A randomized split-mouth clinical trial.

Farias RD1, Closs LQ2, Miguens SA Jr3.

Author information

  • 1a  Master's Student, Graduate Program in Dentistry, Universidade Luterana do Brasil (ULBRA), Canoas, RS, Brazil.
  • 2b  Professor, Department of Orthodontics, Universidade Luterana do Brasil (ULBRA), Canoas, RS, Brazil.
  • 3c  Professor, Department of Oral Medicine, School of Dentistry, Universidade Luterana do Brasil (ULBRA), Canoas, RS, Brazil.



  To evaluate the effect of using low-level laser therapy (LLLT) to control pain and discomfort during orthodontic treatment.


  A randomized, split-mouth clinical trial was conducted with 30 volunteers in need of orthodontic treatment, of both genders, aged between 18 and 40 years, who were randomly divided into two groups. One hemiarch was considered the exposed group (EG) and the other, the placebo group (PG). Both groups had elastic separators placed mesially and distally to the first molars of the two hemiarches at different times. The EG received an AIGaAs diode LLLT (810 nm, 100 mW, 2J/cm2) application for 15 seconds per point (interdental papilla at the mesial, distal, and near the root apex) immediately after separator placement on the maxillary right side. The PG also had elastics placed around the maxillary right molars, but received only simulated LLLT application. The elastics were left in place for 5 days, and after a waiting period of 1 week, they were inserted on the left side in both groups; however, the order of laser application was changed. While the separator remained in place, the patient marked his degree of perceived discomfort on a Visual Analog Scale (VAS) at 5 minutes (T0), 24 hours (T1), and 120 hours (T2), after LLLT application.


  A statistically significant difference was observed (P < .005) in reducing discomfort in the exposed group compared with the placebo group. This reduction of discomfort in the EG was observed at all time intervals.


  A sincle AIGaAs diode LLLT application may be indicated for the control or reduction of pain in the early stages of orthodontic treatment.

Lasers Med Sci.  2012 Sep 18. [Epub ahead of print]

Overview of non-invasive factors (low level laser and low intensity pulsed ultrasound) accelerating tooth movement during orthodontic treatment.

Jawad MM, Husein A, Alam MK, Hassan R, Shaari R.


Orthodontic Unit, School of Dental Sciences, Health Campus, Universiti Sains Malaysia, Kota Bharu, 16150, Kelantan, Malaysia,


The need for orthodontic treatment is increasing all the time. As the treatment is time consuming ranging from a year to several years, any method of reducing the period of treatment and increasing the quality of the tissue will be beneficial to patients. The use of non-invasive techniques such as low level laser therapy and low intensity pulsed ultasound in accelerating orthodontic tooth movement are promising. Thus, this overview study will help to generate more understanding about the background information and the possible applications of them in daily orthodontics, depending on previous literature searching for reviews and original research articles.

Photomed Laser Surg.  2011 Jan 23. [Epub ahead of print]

Influence of Low-Level Laser on the Speed of Orthodontic Movement.

da Silva Sousa MV, Scanavini MA, Sannomiya EK, Velasco LG, Angelieri F.

Department of Orthodontics, Dental School, São Paulo Methodist University , São Paulo, Brazil .


Abstract Introduction: This study evaluated the effect of low-level laser irradiation on the speed of orthodontic tooth movement of canines submitted to initial retraction. Methods: Twenty-six canines were retracted by using NiTi spring (force of 150?g/side). Thirteen of those were irradiated with diode laser (780?nm, 20?mW, 10?sec, 5?J/cm(2)) for 3 days, and the other 13 were not irradiated and thus were considered the control group. Patients were followed up for 4 months, and nine laser applications were performed (three each month). The movement of the canines was evaluated through 3D casts, and the statistical analysis was performed with ANOVA and Tukey tests (p?<?0.05). Periapical radiographs of the studied teeth were submitted to Levander, Malmgreen, and alveolar bone ridge analyses to evaluate tissue integrity and were compared with the Wilcoxon test (p?<?0.05). Results: A statistically significant increase in the movement speed of irradiated canines was observed in comparison with nonirradiated canines in all evaluation periods. No statistically significant difference was observed in bone and root resorption of canines, whether irradiated or not. Conclusion: The diode laser used within the protocol guidelines increased the speed of tooth movement. This might reduce orthodontic treatment time.

Photomed Laser Surg.  2010 Dec;28(6):823-30.

Laser-induced alveolar bone changes during orthodontic movement: a histological study on rodents.

Habib FA, Gama SK, Ramalho LM, Cangussú MC, Santos Neto FP, Lacerda JA, Araújo TM, Pinheiro AL.

Centro de Ortodontia e Ortopedia Facial Prof. José Edimo Soares Martins, School of Dentistry, Federal University of Bahia (UFBA), Salvador, Brazil.


OBJECTIVE: The aim of this study was to assess by light microscopy changes in alveolar bone during orthodontic movement in rats.

BACKGROUND: Orthodontic movement causes both removal and deposition of bone tissue. The use of laser phototherapy (LPT) is considered an enhancement factor for bone repair.

METHODS: Thirty Wistar rats were divided into two groups (n?=?15) and subdivided according to animal death (7,13, and 19 days). Half of the animals in each group were treated with LPT during orthodontic movement. After animal death, specimens were processed and underwent histological and semi-quantitative analyses (HE and Sirius red).

RESULTS: LPT-irradiated specimens showed significantly higher numbers of osteoclasts when compared with controls at both 7 (p?=?0.015) and 19 (p?=?0.007) days, as well as significant increases in the number of osteoblasts (p?=?0.015) between days 7 and 13. The amount of collagen matrix was significantly reduced between days 7 and 13 at both pressure and tension sites in controls (p?=?0.015) but not in LPT-treated animals. LPT-treated subjects showed significantly greater deposition of collagen matrix at the pressure site at both the thirteenth (p?=?0.007) and nineteenth days (p?=?0.001). At the tension site, a significant increase in the amount of collagen matrix was observed in non-irradiated specimens (p?=?0.048) between days 7 and 19.

CONCLUSIONS: LPT caused significant histological changes in the alveolar bone during induced tooth movement, including alterations in the number of both osteoclasts and osteoblasts and in collagen deposition in both pressure and tension areas.

Photomed Laser Surg.  2010 Dec;28(6):757-62.

Effects of two low-intensity laser therapy protocols on experimental tooth movement.

Marquezan M, Bolognese AM, Araújo MT.

Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.


OBJECTIVE: The purpose of this in vivo study was to determine the effect of two low-intensity laser therapy (LILT) protocols on macroscopic and microscopic parameters of experimental tooth movement.

MATERIALS AND METHODS: To induce experimental tooth movement in rats, 40 cN of orthodontic force was applied to the left first molars. Next, a gallium-aluminum-arsenide (Ga-Al-As) diode laser with a wavelength of 830 nm and power output of 100?mW was applied with fluence of 6000?J/cm(2) on the area around the moved tooth. Two different application protocols were used in the experimental groups: one with daily irradiation and another with irradiation during early stages. Macroscopic and microscopic analyses were performed at days 2 and 7 of tooth movement. The amount of tooth movement was measured with a caliper, and tartrate-resistant acid phosphatase and picrosirius staining were used to enable identification of osteoclasts and immature collagen, respectively.

RESULTS: The amount of tooth movement did not differ between the irradiated and nonirradiated groups on days 2 and 7 of the experiment. On day 2, no difference was observed in the number of osteoclasts or the percentage of immature collagen. On day 7, there was an increase in the number of osteoclasts after daily applications of LILT, while two applications produced no significant difference from control. The amount of immature collagen on the tension side significantly increased in the nonirradiated group and when LILT was applied for only 2 d, whereas it was shown to be inhibited by daily LILT applications (p?<?0.05).

CONCLUSION: The tested LILT protocols were unable to accelerate tooth movement. Even though the number of osteoclasts increased when LILT was applied daily, the repair at the tension zone was inhibited.

Photomed Laser Surg. 2010 Oct;28 Suppl 2:S79-83. Epub 2010 Oct 8.

Tooth movement after infrared laser phototherapy: clinical study in rodents.

Gama SK, Habib FA, Monteiro JS, Paraguassú GM, Araújo TM, Cangussú MC, Pinheiro AL.

Centro de Ortodontia e Ortopedia Facial Prof. José Édimo Soares Martins, School of Dentistry, Federal University of Bahia (UFBA), Salvador, BA, Brazil.


OBJECTIVES: The aim of this research was to investigate the influence of low-power laser on tooth movement in rats.

BACKGROUND: Tooth movement is closely related to the process of bone remodeling. The biologic result, with the application of a force to the tooth, is bone absorption on the pressure side and neoformation on the traction side of the alveolar bone. The laser photobiomodulation is capable of providing an increase in cellular metabolism, blood flow, and lymphatic drainage.

METHODS: Thirty young-adult male Wistar rats weighing between 250 and 300 g were divided into two groups, control and experimental, containing 15 animals each. The animals received orthodontic devices calibrated to release a force of 40 g/F, with the purpose of moving the first upper molar mesially. Low-intensity laser, wavelength 790 nm, was used in the experimental group; the dose was 4.5 J/cm(2) per point, mesial and distal, on the palatal side, 11 J/cm(2) on the buccal side, and this procedure was repeated every 48 h, totaling nine applications. The active movement was clinically evaluated after 7, 13, and 19 days.

RESULTS AND CONCLUSION: The results showed no statistically significant difference, p = 0.079 (T0-T7), p = 0.597 (T7-T13), and p = 0.550 (T13-T19) between the laser and control groups on the amount of tooth movement in the different times evaluated. It may be concluded that laser phototherapy, with the parameters in the present study, did not significantly increase the amount of tooth displacement during induced orthodontic movement in rodents.

Eur J Orthod. 2010 Apr;32(2):131-9. Epub 2010 Feb 16.

Low-energy laser irradiation facilitates the velocity of tooth movement and the expressions of matrix metalloproteinase-9, cathepsin K, and alpha(v) beta(3) integrin in rats.

Yamaguchi M, Hayashi M, Fujita S, Yoshida T, Utsunomiya T, Yamamoto H, Kasai K.

Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.


It has previously been reported that low-energy laser irradiation stimulated the velocity of tooth movement via the receptor activator of nuclear factor kappa B (RANK)/RANK ligand and the macrophage colony-stimulating factor/its receptor (c-Fms) systems. Matrix metalloproteinase (MMP)-9, cathepsin K, and alpha(v) beta(3) [alpha(v)beta3] integrin are essential for osteoclastogenesis; therefore, the present study was designed to examine the effects of low-energy laser irradiation on the expression of MMP-9, cathepsin K, and alpha(v)beta3 integrin during experimental tooth movement. Fifty male, 6-week-old Wistar strain rats were used in the experiment. A total force of 10g was applied to the rat molars to induce tooth movement. A Ga-Al-As diode laser was used to irradiate the area around the moving tooth and, after 7 days, the amount of tooth movement was measured. To determine the amount of tooth movement, plaster models of the maxillae were made using a silicone impression material before (day 0) and after tooth movement (days 1, 2, 3, 4, and 7). The models were scanned using a contact-type three-dimensional (3-D) measurement apparatus. Immunohistochemical staining for MMP-9, cathepsin K, and integrin subunits of alpha(v)beta3 was performed. Intergroup comparisons of the average values were conducted with a Mann-Whitney U-test for tooth movement and the number of tartrate-resistant acid phosphatase (TRAP), MMP-9, cathepsin K, and integrin subunits of alpha(v)beta3-positive cells. In the laser-irradiated group, the amount of tooth movement was significantly greater than that in the non-irradiated group at the end of the experiment (P < 0.05). Cells positively stained with TRAP, MMP-9, cathepsin K, and integrin subunits of alpha(v)beta3 were found to be significantly increased in the irradiated group on days 2-7 compared with those in the non-irradiated group (P < 0.05). These findings suggest that low-energy laser irradiation facilitates the velocity of tooth movement and MMP-9, cathepsin K, and integrin subunits of alpha(v)beta3 expression in rats.

Angle Orthod.  2010 Jan;80(1):116-22.

Effects of low-level laser therapy and orthodontic tooth movement on dental pulps in rats.

Abi-Ramia LB, Stuani AS, Stuani AS, Stuani MB, Mendes Ade M.

Department of Pediatric Dentistry and Orthodontics, Division of Orthodontics, State University of Rio de Janeiro, Rio de Janeiro, Brazil.


OBJECTIVES: To describe the microscopic pulpal reactions resulting from orthodontically induced tooth movement associated with low-level laser therapy (LLLT) in rats.

MATERIALS AND METHODS: Forty-five young male Wistar rats were randomly assigned to three groups. In group I (n = 20), the maxillary right first molars were submitted to orthodontic movement with placement of a coil spring. In group II (n = 20), the teeth were submitted to orthodontic movement plus LLLT at 4 seconds per point (buccal, palatal, and mesial) with a GaAlAs diode laser source (830 nm, 100 mW, 18 J/cm(2)). Group III (n = 5) served as a control (no orthodontic movement or LLLT). Groups I and II were divided into four subgroups according to the time elapsed between the start of tooth movement and sacrifice (12 hours, 24 hours, 3 days, and 7 days).

RESULTS: Up until the 3-day period, the specimens in group I presented a thicker odontoblastic layer, no cell-free zone of Weil, pulp core with differentiated mesenchymal and defense cells, and a high concentration of blood vessels. In group II, at the 12- and 24-hour time points, the odontoblastic layer was disorganized and the cell-free zone of Weil was absent, presenting undifferentiated cells, intensive vascularization with congested capillaries, and scarce defense cells in the cell-rich zone. In groups I and II, pulpal responses to the stimuli were more intense in the area underneath the region of application of the force or force/laser.

CONCLUSIONS: The orthodontic-induced tooth movement and LLLT association showed reversible hyperemia as a tissue response to the stimulus. LLLT leads to a faster repair of the pulpal tissue due to orthodontic movement.

Orthod Craniofac Res. 2009 Nov;12(4):289-98.

Low-energy laser irradiation accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling.

Yoshida T, Yamaguchi M, Utsunomiya T, Kato M, Arai Y, Kaneda T, Yamamoto H, Kasai K. Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.

INTRODUCTION: Previously, the authors have reported the acceleration of tooth movement and osteoclastogenesis on the pressure site in an experimental tooth movement model by low-energy laser irradiation (LELI), which stimulated the RANK/RANKL system and c-fms/macrophage colony-stimulating factor system. However, the effect of LELI on osteogenesis on the tension site is not known clearly. Moreover, the temporal changes in alveolar bone during tooth movement have not been investigated as yet. Therefore, the present study was designed to examine the effects of LELI on alveolar bone remodeling during experimental tooth movement, and observe the temporal bone mineral density (BMD) using micro-computed tomography (muCT). MATERIALS AND METHODS: To induce experimental tooth movement in rats, 10 g force was applied to the upper right first molar with Nickel titanium closed-coil. Next, a gallium-aluminum-arsenide (Ga-Al-As) diode laser was used to irradiate the area around the moved tooth, and BMD and the amount of tooth movement were measured by muCT scanning for 21 days. Histopathological examination was also performed. RESULTS: The amount of tooth movement in the LELI group was significantly greater than in the non-irradiation group by the end of the experimental period. Further, compared with the non-irradiation group, the fall of BMD was less in the LELI group. CONCLUSION: These findings suggest that LELI accelerates the velocity of tooth movement via stimulation of the alveolar bone remodeling.

Lasers Surg Med. 2009 Sep;41(7):524-33.

Effects of low-level laser therapy after Corticision on tooth movement and paradental remodeling.

Kim SJ, Moon SU, Kang SG, Park YG.

Department of Orthodontics, Oral Biology Research Institute, College of Dentistry, Kyung-Hee University, Seoul 130-701, Korea.


BACKGROUND AND OBJECTIVE: Both Corticision and low-level laser therapy (LLLT) are known to affect the rate of tooth movement. Our objective was to investigate the combined effects of Corticision and LLLT on the tooth movement rate and paradental remodeling in beagles.

STUDY DESIGN/MATERIALS AND METHODS: The maxillary second premolars (n = 24) of 12 beagles were randomly divided into four groups (n = 6 per group) based on the treatment modality: group A, only orthodontic force (control); group B, orthodontic force plus Corticision; group C, orthodontic force plus LLLT; group D, orthodontic force plus Corticision and LLLT.

RESULTS: Ratios of second premolar-to-canine movement were greater by 2.23-fold in group B and 2.08-fold in group C, but 0.52-fold lesser in group D than in group A. The peak velocity was observed at an earlier stage of tooth movement in group B but at a later stage in group C during the 8-week treatment period. At week 8, both tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts on the compression side and proliferating cell nuclear antigen (PCNA)-positive osteoblasts on the tension side increased significantly (P<.05) in group C but decreased in group D. Histomorphometric analysis revealed that the mean apposition length of newly formed mineralized bone during the 8 weeks of treatment significantly increased in both group B (2.8-fold) and group C (2.2-fold). In group D, the labeling lines on lamina dura were thin and discontinuous, but intratrabecular remodeling and lamellation were found to be active.

CONCLUSION: Periodic LLLT after Corticision around a moving tooth decreased the tooth movement rate and alveolar remodeling activity.

Lasers Med Sci. 2008 Jan;23(1):27-33. Epub 2007 Mar 15.

The effect of low-level laser therapy during orthodontic movement: a preliminary study.

Youssef M, Ashkar S, Hamade E, Gutknecht N, Lampert F, Mir M.

Dental School, Damascus University, Damascus, Syria.


It has been emphasized that one of the most valuable treatment objectives in dental practice is to afford the patient a pain-free treatment. By the evolution of the laser applications, the dental committee aimed to achieve this goal without analgesic drugs and painful methods. Orthodontic treatment is one of these concerns, that one of the major components of patient to reject this treatment is the pain accompanied during the different treatment phases. Another great concern of the patient is not to get through prolonged periods of treatment. The aim of this study is to evaluate the effect of the low-level (GaAlAs) diode laser (809 nm, 100 mW) on the canine retraction during an orthodontic movement and to assess pain level during this treatment. A group of 15 adult patients with age ranging from 14 to 23 years attended the orthodontic department at Dental School, Damascus University. The treatment plan for these patients included extraction of the upper and lower first premolars because there was not enough space for a complete alignment or presence of biprotrusion. For each patient, this diagnosis was based on a standard orthodontic documentation with photographs, model casts, cephalometric, panorama, and superior premolar periapical radiographies. The orthodontic treatment was initiated 14 days after the premolar extraction with a standard 18 slot edgewise brackets [Rocky Mountain Company (RMO)]. The canine retraction was accomplished by using prefabricated Ricketts springs (RMO), in both upper and lower jaws. The right side of the upper and lower jaw was chosen to be irradiated with the laser, whereas the left side was considered the control without laser irradiation. The laser was applied with 0-, 3-, 7-, and 14-day intervals. The retraction spring was reactivated on day 21 for all sides. The amount of canine retraction was measured at this stage with a digital electronic caliper (Myoto, Japan) and compared each side of the relative jaw (i.e., upper left canine with upper right canine and lower left canine with lower right canine). The pain level was prompted by a patient questionnaire. The velocity of canine movement was significantly greater in the lased group than in the control group. The pain intensity was also at lower level in the lased group than in the control group throughout the retraction period. Our findings suggest that low-level laser therapy can highly accelerate tooth movement during orthodontic treatment and can also effectively reduce pain level.

Lasers Med Sci. 2007 Nov;22(4):261-4. Epub 2007 Mar 3.

Effects of two types of low-level laser wave lengths (850 and 630 nm) on the orthodontic tooth movements in rabbits.

Seifi M, Shafeei HA, Daneshdoost S, Mir M.

Faculty of Dentistry, Orthodontics Department, Shaheed Beheshti University of Medical Science, Evin, Tehran, Iran.


The effects of low-level lasers on bone cellular activity, bone structures, bone healing, fibroblasts activity and inflammation process have already been investigated. Considering orthodontic tooth movement, which is a complicated inflammatory process involving simultaneous bone apposition and resorption, the aim of this controlled study is to investigate the quantitative effects of a pulsed 850 nm laser (Optodan) and a continuous 630 nm laser (KLO3) on the orthodontic tooth movement in rabbits. This experimental study was conducted on 18 male albino rabbits divided into three equal groups of control, Optodan and KLO3. In all the groups, NiTi-closed coil springs were used on the first mandibular molars with 4-oz tension. The control group was not irradiated by laser, but the teeth in the laser groups were irradiated 9 days according to the periodontal therapeutic protocols. After 16 days, samples were sacrificed. The distance between the distal surface of the first molar and the mesial surface of the second molar was measured with 0.05-mm accuracy. The data were subjected to the statistical tests of Kolmogrov Smirnov and variance analysis. The mean orthodontic tooth movements of the first mandibular molars were 1.7 +/- 0.16 mm in control group, 0.69 +/- 0.16 mm in Optodan group and 0.86 +/- 0.13 mm in KLO3 group. There were statistically significant difference between the control and the two other laser-irradiated groups (P < 0.001). The findings of the present study imply that the amounts of orthodontic tooth movement, after low-level laser therapy, are diminished. It could not be concluded that any low-level laser will reduce the speed of teeth movement in orthodontic treatments, and further studies with less or more energies may show different results.

Lasers Surg Med. 2000;26(3):282-91.

Effects of low-energy laser irradiation on bone remodeling during experimental tooth movement in rats.

Kawasaki K, Shimizu N.

Department of Orthodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.


BACKGROUND AND OBJECTIVE: Low-energy laser irradiation has many anabolic effects such as the acceleration of bone formation. However, its effects on tooth movement, performed by bone resorption and formation, have not been well characterized.

STUDY DESIGN/MATERIALS AND METHODS: A total of 10 g of orthodontic force was applied to rat molars to cause experimental tooth movement. A Ga-Al-As diode laser was used to irradiate the area around the moved tooth, and after 12 days, the amount of tooth movement was measured. Calcein was injected subcutaneously to label the newly formed alveolar bone for quantitative analysis. Immunohistochemical staining of proliferating cell nuclear antigen was performed to evaluate cellular proliferation. TRAPase staining was also performed to facilitate the identification of osteoclasts.

RESULTS: In the laser irradiation group, the amount of tooth movement was significantly greater (1. 3-fold) than that of the nonirradiation group in the end of the experiment. The amount of bone formation and rate of cellular proliferation in the tension side and the number of osteoclasts in the pressure side were all significantly increased in the irradiation group when compared with the nonirradiation group (P < 0. 01).

CONCLUSION: These findings suggest that low-energy laser irradiation can accelerate tooth movement accompanied with alveolar bone remodeling.