NiTi Closed Coil Springs Research Articles

Root Resorption and Alveolar Bone Changes in the Maxillary Canine Retraction Using NiTi Closed-Coil Springs Versus Elastomeric Chains: A Split-Mouth Trial.

To compare apical root resorption and alveolar bone changes induced by the maxillary canine closure procedure performed on patients with Angle Class I malocclusion using NiTi closed-coil springs versus elastomeric chains. Thirty-one adult patients who had been instructed to undergo bilateral maxillary first premolar extraction completed a randomized clinical trial split-mouth study with a double-blind design. Elastomeric chains will be used on the left side, and NiTi closed-coil springs will be used on the right side for patients with even numbers. Elastomeric chains will be used on the right side of patients with an odd number, whereas NiTi closed-coil springs will be used on the left side of patients. For each patient, cone-beam computed tomography of the maxillary canine and lateral cephalometric radiographs were carried out before and after treatment to evaluate apical root resorption and perform cephalometric measurements. The tooth root length decreased by 0.90 ± 0.60 mm in the NiTi closed-coil spring group. The alveolar bone level increased by 0.53 ± 0.66 mm on the buccal side and by 0.79 ± 0.72 mm on the lingual side. These changes were statistically significant (P < 0.001). In the elastomeric chain group, the tooth root length was decreased by 0.92 ± 0.69 mm, and the levels of vertical buccal and lingual alveolar bone increased significantly (P < 0.001). Compared to NiTi closed-coil springs and elastomeric chain groups, there was a 0.03 ± 0.878 mm difference in the tooth root length; however, this difference was not statistically significant (P = 0.878). Elastomeric chains and NiTi closed-coil springs both generated tooth root resorption, but the results were comparable and the difference was not statistically significant. There was no statistically significant difference between the elastomeric chain and NiTi closed-coil spring groups regarding the changes in alveolar bone loss around the maxillary canines.

Comparison of Amount of Space Closure During En- Masse Retraction of Maxillary Anterior Teeth Using Three Accelerated Orthodontic Treatment Techniques- Micro Osteo-Perforation, Photo Bio-Modulation and Peizocision : A Retrospective Study

AIM: The study aimed at comparing the amount of space closure using peizocision (PZ) and micro- osteoperforation (MOP) and low-level laser therapy (LLLT). Materials and methods: A retrospective study consisted of 3 groups, sample number of minimum 8 patients per group were estimated using statistical model called an Analysis of Variance, or ANOVA model. Three sets of data were collected. Which included patients who were treated with upper first premolar extraction for en- masse retraction of maxillary anterior teeth using NiTi closed coil spring with regional acceleratory procedures. The data collected was divided into 3 groups, GROUP 1- micro osteo perforations (n=8), GROUP 2- photo bio modulation (n=8), GROUP 3- peizocision (n=8).sing digital Vernier calipers, a direct approach was used to measure all the stone casts obtained before canine retraction (T0) and after the retraction was completed after three months (T1). The statistical analysis was performed on the data acquired about the amount of space closure of en-masse retraction of maxillary anteriors in the PZ, LLLT, and MOP groups. Results: Compared to MOP (2.60mm) and LLLT (2.44mm), the PZ group had a greater mean amount of space closure (5.06mm). In conclusion, the quantity of space closure in piezocision was significantly higher than that in MOP and LLLT, although there was no statistically significant difference between the two. It is imperative that treatment duration be shortened. Finding the most effective and practical method to speed up tooth movement using the biomechanical mechanisms that are currently in place is therefore necessary

Rotational Control and Retraction of Maxillary Canine Using Self-Ligating Empower Brackets: An In Vivo Study.

Interest in self-ligating brackets is generally smoother and more comfortable. To compare rate of retraction and rotational control of maxillary canines with self-ligating MBT brackets on one side and conventional MBT brackets on the other side of the maxillary arch. Ten subjects with a mean age range of 18 to 25 years were selected. For each patient in the maxillary arch, bonding was performed with 0.022-inch slot conventional MBT brackets on one side and 0.022-inch slot self-ligating MBT brackets on the other side. Stainless steel 0.009-inch ligatures are used for conventional ligation. Retraction of canines was performed with 0.019 × 0.025-inch stainless steel wires using NiTi closed coil springs with eyelets of 12 mm and 9 mm. The force of retraction was measured using a dynamometer. Dental casts were made at each time interval to record the canine retraction rate (in mm) and rotation (in degrees). The mean difference in the retraction rate was 0.045 mm/month between self-ligating and conventional brackets, respectively (P > 0.05). The mean difference of total rotation of canines with self-ligating and conventional brackets was 1.5°, which gives evidence that there was less rotation of canines with self-ligating brackets. There was no statistically significant difference in canine retraction rates between conventional and self-ligating brackets. Secure ligation with the self-ligating brackets showed better rotational control than the conventional brackets.

Biomechanical Simulation of Orthodontic En-Bloc Retraction Comparing Compound Technique and Sliding Mechanics Using a HOSEA Robotic Device.

En-bloc retraction is a common procedure in orthodontic therapy. The application of palatal root torque moments is required to control incisor inclination during retraction, yet studies comparing forces and moments with respect to different mechanics are lacking. This study aimed to investigate the forces and moments during orthodontic en-bloc retraction using a robotic biomechanical simulation system, comparing two distinct approaches: (I) compound technique [stainless steel (SS) combined with nickel-titanium (NiTi)] using industrially pretorqued retraction-torque-archwires (RTA) in combination with NiTi closed coil springs; (II) conventional sliding mechanics using SS archwires with manually applied anterior twist bends in combination with elastic chains. Two dimensions (0.017" × 0.025" and 0.018" × 0.025") and ten archwires per group were investigated using 0.022" slot self-ligating brackets. Kruskal-Wallis tests with a significance level of α = 0.05 were conducted. The biomechanical simulation showed that en-bloc retraction was characterized by a series of tipping and uprighting movements, differing significantly regarding the examined mechanics. Collateral forces and moments occurred in all groups. Notably, RTA exhibited fewer extrusive forces. The most bodily movement was achieved with the compound technique and the 0.018" × 0.025" RTA. Sliding mechanics exhibited maximum palatal root torque moments of more than 20 Nmm, exceeding recommended values.

An Immunohistochemical and Histological Study of the Animal Periodontal Ligament During Orthodontic Force Application with Concomitant Application of Electric Current - An Animal Study.

The application of direct current can have a significant impact on the rate of tooth movement and surrounding periodontal ligament collagen turnover. This study aims to provide insight into the optimal characteristics of applied current to achieve enhanced tissue response. Eighteen male Wistar rats were divided into three groups (I, II, and III). Split mouth design was used, and each side was allocated into an experimental group or control group. Experimental sides of groups I, II, and III received 20, 10, and 15 μA of current (15 min, twice daily for 3 days). Both the experimental and control groups receive an orthodontic force via the NiTi closed coil spring. The amount of tooth movement was determined daily. Immunohistochemistry slides were scored using the immunoreactive scoring (IRS) system for collagen types I and III. One-way Analysis of Variance (ANOVA) and Tukey post hoc test were used to analyse the rate of tooth movement, while Mann-Whitney test was used to analyse IRS distribution between control and experimental groups. Compared with the control group, there was a statistically significant difference in tooth movement in all the experimental groups, with group 3 showing the maximum rate on days 2 and 3. This was supported by immunoreactive scores for both collagen types I and III. After 72 hours, the expression of collagen types 1 and 3 increased significantly for group III. This finding was in harmony with the rate of tooth movement, which was maximum for group 3 (15 μA) as compared to other groups.

Patient-Reported Outcome Measures of Flapless Corticotomy with Low-Level Laser Therapy in En Masse Retraction of Upper Anterior Teeth: A Three-Arm Randomized Controlled Trial.

(1) Background: This study aimed to compare patient-reported outcome measures when accelerating en masse retraction between the piezocision procedure and the subsequent application of low-level laser therapy (FC+LLLT), with the piezocision alone (FC), and in a control group. (2) Methods: A three-arm randomized controlled trial (RCT) was conducted involving 60 patients (41 females and 19 males) with Class II division I malocclusion. The en masse retraction was performed using NiTi closed coil springs attached to miniscrews. The LLLT was performed using an 808 nm Ga-Al-As diode laser. Patient responses regarding pain, discomfort, swelling, and chewing difficulties were reported at ten assessment points. (3) Results: The greatest pain levels were observed 24 h after the application of force during the first and third months of retraction. The mean pain, discomfort, swelling, and chewing difficulties were significantly smaller in the control group than in the FC and FC+LLLT groups. High satisfaction levels were reported in all three groups (p < 0.05). (4) Conclusions: The accelerated en masse retraction via piezocision, followed by a small course of LLLT, was accompanied by significantly fewer pain, discomfort, and chewing difficulties than the control group. LLLT is a valuable addition to piezocision, with an improved patient experience.

Efek Ekstrak Buah Delima Merah terhadap Jumlah Fibroblas di Ligamen Periodontal Daerah Tarikan Gigi Tikus Wistar Selama Pergerakan Gigi Ortodonti

Orthodontic useful for repairing the arrangement of teeth by remodeling the alveolar bone and periodontal ligament and then fibroblast proliferation will occur. Fibroblast play a role in the formation of collagen fibers that will connect teeth to bones. Orthodontic takes a long time so it takes a method to speed it up. One of them can use red pomegranate extract which contains antioxidants. This Research purpose to analyze the effect and impact of the duration of administration of red pomegranate extract on the number of fibroblasts in the 1st, 2nd, and 3rd weeks of the periodontal ligament in the tooth-tensioning area of wistar rats during orthodontic tooth movement. 36 rats divided into 6 groups: the group with orthodontic appliance installation without red pomegranate extract for 1 week (A), 2 weeks (B), and 3 weeks (C), and the orthodontic appliance installation group with red pomegranate extract administration for 1 week. weeks (D), 2 weeks (E) and 3 weeks (F). The provision of orthodontic mechanical forces by placing a ligature on the right M1 tooth and both maxillary incisors. Then the M1 is moved mesial using a tension gauge to produce a force of 11.5 gF with Ni-Ti closed coil spring. When the rats were euthanized and histology was made with Haematoxylin Eosin (HE) staining. Fibroblasts were observed by using microscope with 400 magnification in 3 fields of view. The average number of fibroblasts in all groups (A, B, C, D, E and F) increased and in the LSD test it was found that between groups there was a significant difference because it had a p-value ≤ 0.05 Red pomegranate extract increase the number of fibroblasts in the periodontal ligament tension area and there is an increase in the number of fibroblasts in the 1st week to the 3rd week.

A Comparative evaluation of stress distribution in bone and mini-implant during en-masse retraction of anterior teeth in maxilla using forces from anchorage units (mini-implants and molar hook) to both canine hook and arch wire hook. An FEM study

The study aimed to compare and evaluate the stress that was distributed around mini-implant, molar hook and anterior dentition during its en-masse retraction from both canine hook and arch-wire hook. Four FEM models of maxilla were created to carry out en-masse retraction of the anterior teeth using forces from mini-implant and molar hook to both arch-wire hook and canine hook. The force of 200 grams was applied with Ni-Ti closed coil spring in all four models to carry out anterior teeth retraction. Stress distribution were then analyzed. The mini-implant group showed higher stresses on the implant when compared to the molar hook group. The molar hook groups showed more stress on the dentition than that of the mini-implant group. The models where the arch-wire hook used for retraction showed less stress values on the bone, teeth, dentition, PDL when compared with that of the canine hook.The arch-wire hook can be considered a better option than the canine hook. When forces were applied to the arch-wire hook lesser stresses were seen on bone, teeth, dentition, and PDL. The implant-supported group showed lesser stress values on teeth when compared with that of the molar hook group.

Expression of TNF-α and TGF-β after the Administration of Cacao Bean Extract on Alveolar Bone

Background: Teeth that are given orthodontic forces can relapse because of excessive resorption on the pressure side. Cocoa bean extract enhances bone apposition during bone remodeling by increasing osteoblast proliferation. This research aimed to ascertain molecular mechanisms of alveolar bone during orthodontic tooth movement applied with cacao bean extract (Theobroma cacao L.) through TNF-α and TGF-β, expressions. Methods: This study utilized an experimental laboratory posttest-only control group design. The NiTi closed coil spring was braced between the right upper first molar and the upper incisor, a strength of 10gf was estimated utilizing a tension gauge to mesially move the upper molars. The total 36 were divided into six groups, Wistar rats were beheaded on days 7 and 14 of treatment. Immunohistochemical staining was utilized to show TNF-α and TGF-β expression. Results were assessed using the one-way ANOVA analysis. Results: The immunohistochemistry findings in osteoclast cells that demonstrate positive results for TGF-β and TNF-α, expression by immunohistochemical staining calculated for each group (control, positive control, treatment). The treatment group (Q14) showed reduced expression (2±0.957) of TNF-α in osteoclast cells. TGF-β, on the other hand, was found with diminished expression in osteoblast cells C-7 and C-14 (3.75±0.816, 3.25±0.957) and increases in the treatment group (Q14) (11.25±0.957). significantly (p=0.000). Conclusion: The administration of cacao bean extract on days 7 and 14 could decrease the expression of TNF-α and increase TGF-β of the treatment group. Therefore, with an increased TNF-α apposition process, relapse after orthodontic treatment can be prevented to accelerate the orthodontic treatment.

Effect of Submucosal Injection of Platelet-rich Plasma on the Rate of Canine Retraction – A Split-mouth Randomized Clinical Study

Abstract Introduction: The use of platelet-rich plasma (PRP) has gained popularity in orthodontics in the past decade. PRP is an autologous concentration of platelets rich in growth factors and is hypothesized to play a role in orthodontic tooth movement (OTM) due to its bone remodeling capacity. Objective: The aim of this study was to determine the effect of PRP on the rate of tooth movement in humans. Materials and Methods: Fourteen patients requiring bilateral extraction of upper first premolars were included in the study. PRP (×4) was prepared and injected in the alveolar mucosa, distal to canine on experimental sides. Canine retraction was initiated on the same day of PRP injection using NiTi closed coil springs on both sides. The amount of canine retraction was measured and compared between both sides at the 4th, 8th, 12th, and 16th weeks by measuring the distance between lateral incisor and canine on the cast. Results: Results showed mean displacement of 1.355 mm, 1.232 mm, 1.191 mm, and 1.085 mm on experimental side and 1.265 mm, 1.126 mm, 1.031 mm, and 0.879 mm on control side at the 4th, 8th, 12th, and 16th weeks, respectively. Although increased OTM (13.85% or 1.1 times faster) was observed on experimental side at all time intervals compared to the control group, the result was not statistically significant. Conclusion: 4× concentration of PRP does not accelerate OTM significantly.

1853-PUB: Extrapancreatic Effects of GIP on Bone

Glucose-dependent insulinotropic polypeptide (GIP) exhibits extrapancreatic effects through the receptor for GIP (GIPR). In this study, we used Ni-Ti Closed Coil Spring (Ni-Ti) in GIPR-deficient mice (GIPRKO) and wild-type mice (WT) to investigate the effect of GIP on force-induced bone remodeling due to orthodontic tooth movement. It was investigated. Ni-Ti was attached between the maxillary bone and the maxillary left first molar (M1) of GIPRKO and WT, and mechanical load was applied by pulling the M1 in the mesial direction. Remaining amount and bone quality were measured. A histological examination of the maxilla was also performed. As a result, compared to WT, GIPRKO showed a significant increase in tooth movement distance and a significant decrease in residual alveolar bone mass. TRAP staining showed an increase in osteoclasts in GIPRKO compared to WT on the tooth moving side. We also found that GIPRKO reduced osteoblasts in the steady state and suppressed osteoblasts after tooth movement. These results suggest that GIPRK impairs bone remodeling through increased bone resorption due to mechanical load, and that GIP plays an important role in bone remodeling. Disclosure T.Yamauchi: None. S.Goto: None. K.Naruse: None. N.Nakamura: None. M.Miyabe: None. M.Ito: None. R.Hoshino: None. S.Kanada: None. T.Sekiya: None. T.Matsubara: None. K.Miyazawa: None.

Ekspresi BMP2 dan TRAF6 pada Jaringan Periodontal setelah Pemberian Ekstrak Kopi Robusta selama Pergerakan Gigi Ortodonti

Orthodontic tooth movement occurs due to mechanical stimulation followed by alveolar bone and periodontal ligament remodeling. Bone remodeling is the process of bone resorption in areas of tension and bone formation in areas of tension. Various techniques and drugs are used to speed up orthodontic treatment. This study aims to analyze the expression of BMP2 and TRAP6 on orthodontic tooth movement after the administration of Robusta coffee extract. Twenty-four Wistar rats were divided into 4 groups: C1 (2 weeks) and C2 (3 weeks) groups: rats were given orthodontic mechanical force (OMF) and T1 (2 weeks) and T2 (3 weeks) groups rats were given OMF and Robusta coffee extract. OMF in rats was performed by moving the maxillary right permanent molars mesially with a Niti closed coil spring. Observations were made on the 15th and 22nd day by immunohistochemical examination to determine the expression of BMP2 and TRAP6. Administration of Robusta coffee extract for 2 weeks and 3 weeks increased BMP2 and TRAP6 expression (p &lt;0.05). Administration of Robusta coffee extract increased the expression of BMP2 and TRAP6 in the alveolar bone during orthodontic tooth movement.

Analysis of the Potency of Robusta Coffee (Coffea canephora) to Increase the Expression of FGF2, Collagen 1 and ALP in the Periodontal Ligament During Orthodontic Tooth Movement

Orthodontic treatment is relatively long and various efforts have been made to speed up the movement of orthodontic teeth. Coffee contains substances called caffeine (1,3,7 trimethylxanthine), chlorogenic acid and caffeic acid, as well as flavonoids which have antioxidant effects. Chlorogenic acid and caffeic acid are antioxidants that can reduce oxidative stress in osteoblasts and promote osteogenesis. The study aimed to analyze the expression of FGF2, Collagen 1 and ALP, on the movement of orthodontic teeth after administration of Robusta coffee extract. 24 wistar rats divided into 4 groups, namely groups C1 and C2: Rats were given orthodontic mechanical force (OMF) for 2 and 3 weeks and groups T1 and T2: Mice were given OMF and Robusta coffee extract for 2 and 3 weeks. OMF in mice (rats) was carried out by means of the right maxillary first molars teeth and on both maxillary incisors were given ligature wires. Then the right maxillary first molars moved to the mesial with a Niti closed coil spring. Observations were made on the day 15 and day 22 with immunohistochemical examinations to determine the expression of FGF2, Collagen 1 and ALP. The results indicated that administration of Robusta coffee extract for 2 and 3 weeks significantly increased the [expression of FGF2, Collagen 1 and ALP. The expression of FGF2, Collagen 1 and ALP (expression of GFß1, IGF1 and PDGF). The expression of TGFß1, IGF1 and PDGF during 3 weeks was greater than that at 2 weeks (p &lt; 0.05. Robusta coffee extract can be used as an alternative ingredient in accelerating orthodontic treatment. HIGHLIGHTS Orthodontic treatment requires quite a long time and various efforts have been made to speed uporthodontic tooth movement, for example with drugs Robusta coffee extract contains ingredients that have antioxidant effects that can reduce oxidativestress on osteoblasts and promote osteogenesis Robusta coffee extract effectively increases the expression of FGF2, Collagen-1 and ALP which are bone formation markers GRAPHICAL ABSTRACT

In vitro study of the stretching time-associated force magnitude generated by NiTi and stainless-steel closed coil springs

Closed coil spring is an additional tool in a fixed-orthodontic treatment. NiTi is an orthodontic alloy that has shape memory and elasticity features, while stainless steel has properties of malleability, low friction between wire-bracket, as well as easy soldering and welding. Various properties of closed coil springs have been widely studied, but research on the stretching time remains unclear. This study aimed to determine the effect and differences in the stretching time for 7 days, 14 days, 21 days, and 28 days on the force magnitude of NiTi and stainless-steel (SS) closed coil spring. A 7 x 5 x 1 cm acrylic blocks with 1 cm acrylic posts were employed, and 25 mm closed coil springs were attached to the acrylic posts using modified T-sticks. The springs were immersed in an artificial saliva with pH of 6.75 for 7, 14, 21, and 28 days in an incubator at 37 °C. The container was removed from the incubator and the force was measured using a universal testing machine. Kolmogorov-Smirnoff test was carried out to analyze parametricdata, while independent T-test was used to determine the difference between each group. There was a significant effect of stretching time on the force magnitude of the SS closed coil spring in all the groups (p &lt; 0.05). There was no significant effect of stretching time on the force of the NiTi closed coil spring on days 7, 14, and 21 (p &gt; 0.05) but there was a significant effect on day 28 (p &lt; 0.05). A significant effect between the ratio of the SS and NiTi closed coil spring (p &lt; 0.05) was confirmed. Longer stretching time indicated a force loss in the SS closed-coil spring, while the NiTi spring had a more stable force which implies a formidable treatment-time for orthodontic treatment.

Different Methods of Canine Retraction- Part 1

Background: This review aimed at explaining different methods of canine retraction along the archwire. Methods: Searching for different methods of canine retraction using fixed orthodontic appliances was carried out using different databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, Research Gate, and hand searching from 1930 till February 2022. Results: After excluding the duplicate articles, papers describing the methods of canine retraction along the archwires were included. The most commonly used methods are NiTi closed coil spring and elastic chain. Conclusions: Various methods of canine retraction along the archwires were explained in detail regarding their advantages, disadvantages, and comparisons among different methods supported by clinical trials, systematic review, and meta-analysis. The preferred method is canine retraction with NiTi closed coil spring with 150 and 200 gm. Elastic chain is considered an alternative, low-cost option.

Finite Element Study to Compare Stress Distribution and Displacement in the Palatal Implant in Lingual Orthodontics in Four Different Combinations of Palatal Implant and Lever Arm

Introduction: The choice of orthodontic appliance depends upon the patients age, profession and availability of them. Lingual orthodontic appliances are preferred over labial by patients because of its invisibility. The aim of this research is to compare the Von Mises stress distribution and displacement of palatal implants in the lingual orthodontic system among four different combinations of palatal implant and lever arm. Materials and Method: Four Finite element models were constructed for the bilaterally extracted first premolar maxillary arch. In all these models 0.018” slot lingual brackets were placed at the center of the clinical crown. A similar retraction force (150gm) was applied with the help of NiTi closed coil spring for all the models but the length of the lever arm vary as well as the palatal implant position also varies in these models. Finite element analysis was then performed to compare the Von Mises stress distribution, and displacement of the palatal implant using ANSYS 12.1 software. Result: In this study, displacement was the same (0.0005 mm) for all four models. Highest amount von mises stress was observed in Model 3 (3.4798 MPa) as a comparison to Model 1 (2.5442 MPa), Model 2 (2.5018 MPa), and Model 4 (3.3854 MPa). The stress value for the palatal implant was within the acceptable fatigue limit of the titanium of 193 MPa therefore all four models combination was safe for the clinical application. Conclusion: Double palatal implant systems were more effective in comparison to the single palatal implant system in lingual orthodontics. In this study, we found that the displacement of the palatal implants was not affected by the length of the lever-arm and the amount of stress was decreased when we increase the length of the lever-arm.

Letter to the Editor

Re: “Comprehensive comparison of canine retraction using NiTi closed coil springs vs elastomeric chains: A split-mouth randomized controlled trial” by Haya A. Barsoum, Hend S. ElSsayed, Fouad A. El Sharaby, Juan Martin Palomo, Yehya A. Mostafa et al. Angle Orthod 2021;91:441-448.This was an interesting study, and we congratulate the authors for the publication. We wish to ask the authors to clarify a few points from the paper.Thank you for clarifying this information.

Laser assisted accelerated orthodontics – a split mouth study

ABSTRACT Aim The aim is to evaluate the impact of LASER on the rate of orthodontic tooth movement. Materials and method The LASER procedure to assist canine distalization was performed on the right maxillary quadrant, and conventional canine distalization in left maxillary quadrant for all patients. Four perforations of diameter 1.5 mm each were made distal to the canine in non-contact mode. Distalization was initiated immediately after the LASER procedure using NiTi closed coil springs of 9 mm length with an approximate force of 150 gm for both sides. In addition to the rate of canine distalization, pain perceived by the patient was also noted after the surgical procedure. Results The mean rate of canine distalization in the LASER side and control side was 1.43 ± 0.11 mm/month and 1.22 ± 0.11 mm/month, respectively. The distribution of the mean rate of canine distalization between the cases considered is significantly higher on the LASER side as matched to the control side. The mean distance travelled on the experimental side was 6.97 ± 0.55 mm, while it was 5.87 ± 0.55 mm on the control side. The distribution of the mean distance travelled by canine between the cases considered is significantly higher on the LASER side as matched to the control side. A significantly higher proportion of cases showed improved pain perception at 24 hrs compared to pain perception at 3 hrs. Conclusion Use of LASER in cases of individual maxillary canine retraction resulted in a higher rate of canine distalization and shorter duration of overall treatment, with no major complications after LASER-assisted alveolar corticotomies.

Micro-Osteoperforations Induce TNF-α Expression and Accelerate Orthodontic Tooth Movement via TNF-α-Responsive Stromal Cells.

Micro-osteoperforations (MOPs) have been reported to accelerate orthodontic tooth movement (OTM), and tumor necrosis factor (TNF)-α has been reported to play a crucial role in OTM. In this report, the influence of MOPs during OTM was analyzed. We evaluated the expression of TNF-α with and without MOPs by RT-PCR analysis. A Ni-Ti closed coil spring was fixed between the maxillary left first molar and the incisors as an OTM mouse model to move the first molar in the mesial direction. MOPs were prepared on the lingual side and mesial side of the upper first molars. Furthermore, to investigate the target cell of TNF-α for osteoclast formation during OTM with MOPs in vivo, we created four types of chimeric mice in which bone marrow of wild-type (WT) or TNF receptor 1- and 2-deficient mice (KO) was transplanted into lethally irradiated WT or KO mice. The results showed that MOPs increased TNF-α expression, the distance of tooth movement and osteoclast formation significantly. Furthermore, mice with TNF-α-responsive stromal cells showed a significant increase in tooth movement and number of osteoclasts by MOPs. We conclude that MOPs increase TNF-α expression, and tooth movement is dependent on TNF-α-responsive stromal cells.

A CBCT assessment of bone density changes after accelerated orthodontic retraction of canine by microosteoperforations.

AIM:The study was conducted to assess the changes in bone density before and after performing accelerated orthodontic maxillary canine retraction by microosteoperforations (MOPs).MATERIALS AND METHODS:Forty patients (120 cone-beam computed tomography [CBCT] images) within the age group of 15 to 25 years undergoing fixed orthodontic treatment with bilateral maxillary first premolar extraction were enrolled in this study. The right and left sides of the maxillary jaw in the same patients were selected as experimental and control sites. To accelerate the tooth movement, MOPs were performed distal to the canine root in the extraction space under local anesthesia with a miniscrew. Thereafter, the maxillary canine retraction was initiated using a NiTi closed coil spring. The CBCT images were taken and evaluated at the following time intervals: 1 week before MOPs(T0);1 week after MOPs(T1);3 weeks after MOPs(T2).RESULTS:A statistically significant reduction in bone density was observed at the center of resistance of canine on the experimental site (after MOPs) at 1 week and 3 weeks (T0-T1 = 0.000,0.115; T1-T2 = 0.0025,0.0117), whereas a statistically non-significant difference was found 1 week before and 3 weeks later in the control group.CONCLUSION:Accelerated orthodontics by MOPscan result in a substantial reduction in bone density during canine retraction, leading to an increase in the tooth movement rate, hence lowering the overall orthodontic treatment time.