Extraction Of First Premolars Research Articles

Three-dimensional comparison of the effects of sliding mechanics in labial and lingual orthodontics using the finite element method

The extraction of maxillary first premolars is usually the treatment of choice to resolve crowding, alveolar protrusion, or Class II malocclusion. The demand for a lingual orthodontic treatment is increasing because of its esthetic value; therefore, understanding lingual biomechanics is essential to every clinician. This study compared the 3-dimensional (3D) effects of sliding mechanics in labial and lingual orthodontics using the finite element method. Twelve 3D finite element models were created with different power arm heights and miniscrew positions. A 150 g of retraction force was applied from the head of the miniscrew to the power arm. The 3D displacement of the original nodes was measured, and the stress distribution on defined element zones of the periodontal ligament. Different force directions led to different movement patterns and stress distribution. The lingual models showed a more important lingual crown tipping, extrusion, and higher stress values than the labial models. Results were not affected by the vertical position of the miniscrew. Bodily en-masse retraction was not achieved in all models. Adding extra torque to the archwires is essential to prevent excessive lingual crown tipping. The lingual appliance induced more lingual tipping and extrusion of the anterior teeth. Expanding the archwire is important to minimize the risk of intercanine width reduction. The vertical position of the miniscrew does not affect the results of en-masse retraction.

Efficacy of pulsed electromagnetic field in reducing treatment time: A clinical investigation

The long duration of orthodontic treatment is a major concern for the patient. This study aimed to evaluate the efficacy of pulsed electromagnetic field therapy (PEMF) in accelerating the orthodontic tooth movement, thus reducing treatment duration. Nineteen patients requiring extraction of first premolars were selected for this study. The study design was randomly assigned (sealed envelope randomization) split-mouth design. The rate of individual canine retraction by a nickel-titanium closed-coil spring was done. The experimental side received a PEMF generated by a circuit powered by a watch battery. The circuit was embedded in a removable appliance. Foil was used to obstruct the control side from PEMF exposure. Patients were instructed to wear the appliance for 8-10 hours. Appliance with the device was given from the commencement of canine retraction until the canine retraction of one side was complete. Tooth movement was measured on progress models. An average increase of 31% in the rate of tooth movement was observed with the PEMF. PEMF is a good option to reduce orthodontic treatment duration.

Effect of micro-osteoperforations on the rate of orthodontic tooth movement and expression of biomarkers: a randomized controlled clinical trial.

ABSTRACTIntroduction: Micro-osteoperforation is a minimally invasive technique that has been used to accelerate orthodontic tooth movement and reduce treatment duration. However, literature presents conflicting reports about this technique. Objective: To evaluate the effectiveness of micro-osteoperforations on the rate of canine retraction and expression of biomarkers in gingival crevicular fluid (GCF). Methods: This was a randomized clinical trial with split-mouth study design. Thirty adult subjects with age above 18 years (20.32 ± 1.96) who required fixed orthodontic treatment and extraction of maxillary first premolars were enrolled and randomly allocated to either the experimental or control group. Randomization was performed by block randomization method, with a 1:1 allocation ratio. The experimental group received three micro-ostoperforations (MOPs) distal to maxillary canine, using the Lance pilot drill. The retraction of maxillary canine was performed with NiTi coil-spring (150g) in both experimental and control groups. The primary outcome was the evaluation of canine retraction rate, measured on study models from the baseline to 16 weeks of canine retraction. Secondary outcomes were the estimation of alkaline and acid phosphates activity in GCF at 0, 1, 2, 3, and 4 weeks. Results: There was a statistically significant difference in the rate of canine retraction only after the first 4 weeks. Subsequently there was no statistically significant difference from the eighth to the sixteenth weeks between MOPs and control group. There was a statistically significant difference in alkaline and acid phosphates activity in GCF between MOPs and control groups during the initial 4 weeks of canine retraction. Conclusion: Micro-ostoperforation increased the rate of tooth movement only for the first 4 weeks; thereafter, no effect was observed on the rate of canine retraction during 8, 12 and 16 weeks. A marked increase in biomarker activity in the first month was observed.

The effect of two different types of forces on possible root resorption in relation to dentin phosphoprotein levels: a single-blind, split-mouth, randomized controlled trial

BackgroundThe purpose of this 2-arm-parallel split-mouth trial was to evaluate and compare the extent of possible root resorption using dentin phosphoprotein levels in gingival crevicular fluid between controlled continuous and intermittent orthodontic force groups.Materials and methodsA sample of 16 maxillary first premolars from 8 patients requiring bilateral extractions of the upper first premolars as part of their orthodontic treatment were recruited. A buccally directed continuous force of 150 g, reactivated after 28 days, was applied to the upper first premolar on one side for 8 weeks. On the contralateral first premolar, a buccally directed intermittent force (21 days on, 7 days off) of the same magnitude was applied for the same period. Gingival crevicular fluid samples were collected at the beginning of the study, 1st, 3rd, 4th and 5th week, and at the end of the study to quantify and compare dentin phosphoprotein levels in both groups.ResultsDentin phosphoprotein levels showed a higher concentration in the continuous force group than the intermittent force group in week 4 and 8 of sample collection; where the differences were statistically significant (95% CI 0.007–0.14; P < .04) and (95% CI 0.02–0.17; P < .04) respectively. No harm was observed.ConclusionsDentin phosphoprotein was found to be a useful early biomarker to detect and monitor root resorption, showing that the application of an intermittent orthodontic force caused less root resorption than a continuous force.Trial registrationNCT04825665 ClinicalTrials.gov. Registered 1 April 2021—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04825665.

Efficacy of micro-osteoperforation of the alveolar bone by using mini-screw for acceleration of maxillary canine retraction in young adult orthodontic patients: A split-mouth randomized clinical trial

Acceleration of orthodontic tooth movement (OTM) can decrease the rate of complications. This study aimed to assess the efficacy of micro-osteoperforation (MOP) of the alveolar bone for acceleration of OTM by using mini-screws. This split-mouth randomized clinical trial evaluated 25 patients (11 females, 14 males, 16-25 years) with class II division I malocclusion who required canine retraction following the extraction of maxillary first premolar. The patients received similar orthodontic treatment at both sides with MOP on one side (MOP group) and no MOP on the other side (control side). Allocation of MOP to the side of jaw was random using Random Allocation Software in 1:1 distribution and equal numbers. Blinding was not applicable. The rate of canine movement was measured monthly for 5 months and considered as the main outcome. The degree of canine tipping was measured at the end of the intervention as the secondary outcome. All measurements were repeated for 12 patients by the two observers and the intra- and inter-examiner correlation coefficients were found to be 0.946 and 0.925, respectively. Data were analysed by paired t-test and repeated measures ANOVA. Twenty-five patients (11 females, 14 males, 16-25 years) were evaluated. No significant difference was found between the two groups at different time points in the rate of canine movement (P>0.05). The degree of canine tipping in the MOP group was significantly lower than that in the control group (5.34±3.11° versus 7.08±3.70°; P=0.040). Gender had no significant effect on OTM in any group (P>0.05). MOP could not accelerate canine retraction but decreased the degree of canine tipping.

The effect of piezocision vs no piezocision on maxillary extraction space closure: A split-mouth, randomized controlled clinical trial

The aim of this 2-arm-parallel, split-mouth trial was to investigate the effects of piezocision compared with no piezocision on maxillary canine distalization and to evaluate patient perceptions on the surgical procedure. Twenty-two participants requiring extractions of maxillary first premolars were recruited from the Department of Orthodontics (Sydney Dental Hospital) waiting list. After leveling and alignment, a minimum of 3mm space was required for canine retraction. Piezocision cuts distal to the canines were 4mm long and 3mm deep into the buccal cortical plate. The canine retraction was initiated on both sides immediately after surgery, with coil springs delivering 150g of force per side. Random assignment of piezocision or control intervention on the patient's right side was performed (www.randomisation.com) for the random number generation, and allocation concealment was accomplished with opaque, sealed envelopes. Patients were assessed every 6weeks for coil activation and alginate impressions over 18weeks. The primary outcome was the amount of tooth movement in mm. Secondary outcomes were canine rotation, anchorage loss measured on scanned dental models, and patient pain levels and perception on piezocision using visual analog scale questionnaires. Blinding was feasible for the dental model measurements. Twenty patients completed the trial. The treatment×time interaction showed no statistically or clinically significant differences in maxillary extraction space closure (b=-0.02; 95% confidence interval [CI], -0.29 to 0.25; P=0.89) canine rotation (b=-1.45; 95% CI, -4 to 1.09; P=0.26) and anchorage loss (b=-0.02; 95% CI, -0.38 to 0.34; P=0.92). All patients except for one had minimal pain associated with the piezocision surgery but found the procedure tolerable and would recommend it. No harm occurred during the trial. Piezocision-assisted maxillary canine distalization was similar to distalization with conventional orthodontics with patients tolerating the procedure.

Treatment of Skeletal Class III With Extraction And Standard Edgewise: Case Report

Objective: This study was determining the skeletal, dental, and soft tissues changes is respons to camoflage Class III treatment. Methods: A male patient 14 years, 10 months with malocclusion of dental Class I and skelettal Class III, included crowding and crossbite anterior, overbite 3 mm, overjet -1,5 mm, maxillary midline shift to the right 2 mm and mandibular midline shift 1 mm. Treatment was extraction of maxillary and mandibular first premolar with standard edgewise appliance and retention of hawley retainer. After of treatment, correction of the crowding, crossbite anterior and midline, with dental relation class I, normal overbite and overjet is 2 mm. Results: This case is Angle’s class I malocclusion where sagittal interarch relationship is normal, it is preferable to extract in both the arches in order to maintain the interarch relationship, so was that extraction of the right first premolar of maxilla and mandibular. Conclusion: Careful management of the extraction space preserved normal lip support and facial profiles

English

BACKGROUND Local anaesthetics helps in preventing pain during surgical and dental procedures by blocking the peripheral nerves. The primary objective of this investigation was to compare and evaluate 4 % articaine hydrochloride (with 1 : 100000 adrenaline) and 2 % lignocaine hydrochloride (with 1 : 80000 adrenaline) in terms of pulpal anaesthesia, volume of anaesthetic solution administered, need of re-anaesthesia and difficulty of extraction during orthodontic extraction of maxillary first premolars. METHODS This prospective randomized, double-blinded study was conducted on 43 patients of less than 40 years of age requiring bilateral maxillary first premolar extractions for orthodontic purposes. Each patient was randomly assigned to receive either 2 % lignocaine hydrochloride or 4 % articaine hydrochloride for premolar extraction of one side and other solution was administered for premolar extraction of contralateral side spaced 1 to 3 weeks apart. In each patient, the difference in pulpal anaesthesia, volume of anaesthetic solution administered, need of re-anaesthesia, difficulty of extraction and duration of anaesthesia was assessed on administration of lignocaine hydrochloride and articaine hydrochloride. RESULTS Statistically significant difference in pulpal anaesthesia levels was found when the articaine and lignocaine groups (P &gt; 0.05) were compared, with a higher mean pulpal anaesthesia among the articaine group. There was no difference in volume of anaesthetic solution administered on buccal and palatal side among the articaine and lignocaine groups. Only 2.3 % of patients in both the groups required re-anaesthesia on the buccal side. There was no significant difference in difficulty of extraction in both the groups. The articaine group had a longer mean duration of anaesthesia as compared to the lignocaine group which was highly significant. CONCLUSIONS Articaine may be used to replace lignocaine in orthodontic extraction of maxillary premolars with clinical advantages like higher pulpal anaesthesia and longer duration of anaesthesia. KEY WORDS Local Anaesthetic, Lignocaine Hydrochloride, Articaine Hydrochloride, Orthodontic Extraction, Prospective Study, Double-Blinded Study.

Frequency, Pattern and Rationale of Tooth Extractions Among Orthodontic Patients: A 10-year Tertiary Institution Experience

Background and objectives: Tooth extractions are a vital aspect of orthodontic management that enables the orthodontist to achieve good aesthetics and function as well as long term treatment stability for the patient. Extractions may be necessary for various reasons among which are tooth size arch length discrepancy (TSALD), increased overjet and facial profile. The aim of this study was to determine the prevalence, pattern and rationale of tooth extraction among orthodontic patients attending the Orthodontic Unit of the Department of Child Dental Health, University of Port Harcourt Teaching Hospital. Methods. A retrospective study of a cohort of patients who attended one of the outpatient Orthodontic Clinics in the Department of Child Dental Health, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria between 2011 and 2021. Data was collected from the patients’ records. Results. A total of 175 patients comprising 70(40%) males and 105(60%) females were included in the study. 67(38.3%) patients had at least one extraction. Twenty-eight (41.8%) extraction cases had extraction of the first premolars. Two-unit extractions of the maxillary first premolars (13, 46.4%) was the most frequent extraction pattern. Eight (29.6%) had extraction of primary canines only. Twenty-seven (40.3%) participants had extractions due to increased overjet. Over a third of the patients had extraction of at least one tooth. Conclusion. Two-unit extractions of maxillary first premolar was the commonest extraction pattern. Increased overjet was the commonest reason for extraction.

Treatment Effects and Lip Profile Changes Following Surgical Mandibular Advancement Versus Premolar Extractions in Class II Div 1 Malocclusion: A Randomized Controlled Trial.

No randomized controlled trial has compared the treatment outcome between surgical mandibular advancement and premolar extractions in class II malocclusion. This 2-arm parallel randomized controlled trial evaluated the treatment effects and lip profile changes in skeletal class II adult patients subjected to bilateral sagittal split ramus osteotomy for mandibular advancement and those treated with premolar extractions. Seventy skeletal class II patients were accessed and forty-six subjects who fulfilled inclusion criteria were distributed randomly into Group CG (patients: 23, mean age: 21.28 ± 2.69 years) and Group SG (patients: 23, mean age: 21.15 ± 2.64 years). Group CG was subjected to extraction of maxillary first premolars and mandibular second premolars followed by implant supported space closure and Group SG was managed by surgical mandibular advancement. Skeletal, dental, and soft-tissue changes were analyzed. The study was single-blinded (statistical analyzer). Groups were closely matched for baseline parameters. In the present trial there was no loss to follow-up. Though overjet and overbite were optimized in both the groups but significant improvement was seen in surgical cases. Group CG demonstrated statistically significant point "A" remodeling, dentoalveolar changes, and increase in nasolabial angle. Group SG exhibited significant sagittal and vertical skeletal improvement and lip position change. Surgical mandibular advancement was found to be a better treatment modality compared to premolars extraction for managing skeletal class II div 1 malocclusion as it permits greater improvement of the profile and skeletal relationship.

Does mini-implant-supported rapid maxillary expansion cause less root resorption than traditional approaches? A micro-computed tomography study.

ObjectiveThis study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances.MethodsIn total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal–Wallis one-way analysis of variance and Mann–Whitney U test with Bonferroni adjustment.ResultsThe hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05).ConclusionsThe findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

THE USE OF MICRO-OSTEOPERFORATION CONCEPT FOR ACCELERATING DIFFERENTIAL TOOTH MOVEMENT

Objective: To compare the rate of accelerated tooth movement in canine retraction with micro-osteoperforation on one side and control on the other.&#x0D; Study Design: Quasi experimental study.&#x0D; Place and Duration of Study: Orthodontics department, Armed Forces Institute of Dentistry, Rawalpindi Pakistan, from Jul 2018 to Jan 2019.&#x0D; Methodology: A total of 30 patients were inducted. After alignment and extraction of maxillary first premolars, canine retraction was started with closed NiTi coil spring on both sides of the maxillary arch. Micro-osteoperforation was done on the right side and other side was a control side. The distance between the lateral incisor and the canine was measured on both sides before micro-osteoperforation. The same measurements were recorded after three weeks of retraction. The difference between pre and post retraction measurements was recorded. The difference in the rate of canine retraction between both modalities was compared using independent sample t-test.&#x0D; Results: The study included 17 males (56%) and 13 females (43%). The mean rate of tooth movement at experimental side of maxilla was 1.6 ± 0.52 mm and on control side was 0.66 ± 0.31 mm (p&lt;0.05).&#x0D; Conclusion: Micro-osteoperforation was an effective, comfortable, and safe procedure to accelerate tooth movement (1.6 times in accordance with this study). It significantly shorten the duration of orthodontic treatment.

Clinical research: low-level laser therapy in accelerating orthodontic tooth movement

BackgroundThe present study aimed to investigate the effects of low-level laser therapy (LLLT) on orthodontic tooth movement and its correlation with the levels of interleukin-1β (IL-1β), receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in gingival crevicular fluid (GCF).MethodsThis split-mouth design study included 12 patients scheduled for the extraction of both upper first premolars. Patients were randomly selected for experimental group that received left- or right-side radiation with a diode laser (810 nm wavelength, 100 mW power output, 6.29 J/cm2 energy density). Laser treatment was applied on days 0, 7, 14, and 21, after loading the canine retraction forces. GCF concentrations of IL-1β, RANKL, and OPG were analyzed. The upper arch of each patient was scanned with an intraoral scanner to assess tooth movement.ResultsThe cumulative tooth movement over 28 days was significantly higher in the laser group than in the control group. We observed significant reductions in OPG levels and increases in IL-1β and RANKL levels in GCF samples on the experimental sides.ConclusionWith the parameter settings used in this study, LLLT could, to some extent, lead to changes in bone metabolism, which could accelerate orthodontic tooth movement.Trial registration: Chinese Clinical Trial Registry, ChiCTR2000039594. Registered 2 November 2020—Retrospectively registered, www.chictr.org.cn/edit.aspx?pid=62465&htm=4.

Efficacy of Transdermal Diclofenac Patch and Ketoprofen Patch as Postoperative Analgesia after Extraction of First Premolars Bilaterally in Both Arches for Orthodontic Purpose: A Comparative Study.

Aim:The aim of the study was to compare the efficacy of transdermal diclofenac patch with ketoprofen patch as postoperative analgesia after extraction of first premolars bilaterally in both arches for orthodontic purpose.Materials and Methods:A split-mouth technique was used in 52 patients with the age group of 15–25 years for extracting maxillary and mandibular first premolars bilaterally for orthodontic reason. A single ketoprofen patch was used after the extraction of premolars from first and fourth quadrant, whereas for the extraction of second and third quadrant premolars, diclofenac patch was used. All the extractions were performed under local anesthesia. The data were compiled and statistically analyzed using the student's t-test.Results:Mean visual analog scale score for diclofenac and ketoprofen patch was 2.05 (0.75) and 1.09 (0.3), respectively. Thirteen patients required additional medication (25%) and 1 (1.9%) patient with diclofenac and ketoprofen patch, respectively. No major complication or adverse effects were observed in any of the groups.Conclusion:Both diclofenac and ketoprofen transdermal patches are helpful in relieving pain after orthodontic extraction. Patients with diclofenac patch required more additional analgesia within 24 h compared to that with ketoprofen patch. None of the drugs showed any significant adverse effects and were well tolerated by the patients.

Morphological alterations, activity, mRNA fold changes, and aging changes before and after orthodontic force application in young and adult human-derived periodontal ligament cells.

The response of periodontal ligament cells (PDLC) from adult subjects in comparison to those obtained from younger ones to mechanical forces has been a matter of interest recently because of induced senescent changes. This study evaluated and compared cell surface changes and activity, integrin beta 1, and β-actin mRNA fold changes as well as klotho protein secretion capabilities of PDLC from young and adult donors before and after subjecting to orthodontic forces. A total of 40 subjects with bimaxillary dentoalveolar protrusion requiring extraction of first premolars for orthodontic treatment were selected and divided into two groups. Force ranging from 80 to 90 g was applied to maxillary first premolars and extraction was carried out at two different time periods-pre-treatment (control group) and 28 days after force application (experimental group). Periodontal ligament was obtained, and cell surface changes and activity were observed with atomic force microscopy (AFM) and fluorescent tagging. mRNA fold change of integrin beta-1 and β-actin mRNA, as well as beta-galactosidase assay, was performed, and levels of klotho protein were evaluated. AFM nanoindentation and fluorescent tagging indicated increased surface morphological changes in younger cells compared to adult ones. We observed a decrease in integrin beta 1 but an increase in β-actin mRNA levels in PDLC obtained from younger subjects compared to adults, while an increase was observed in SA-β-GAL from adult cells. The level of klotho protein was lower in adult cells in comparison to younger ones. Large sample studies are required to find out a variation in aging characteristics between young and adult PDLC. The study observed significant differences between PDLC obtained from younger and adult subjects in response to orthodontic force application.

Effect of light-emitting diode–mediated photobiomodulation on extraction space closure in adolescents and young adults: A split-mouth, randomized controlled trial

This split-mouth trial aimed to examine the effects of light-emitting diode (LED)-mediated photobiomodulation compared with no photobiomodulation on maxillary canine distalization. Twenty participants (10 males and 10 females; aged 11-20years) requiringbilateral extraction of maxillary first premolars were included from the Sydney Dental Hospital waiting list. After premolar extractions, leveling, and alignment, canines were retracted on 0.020-in stainless steel wires with coil springs delivering 150g of force to each side. Each patient's right side was randomly assigned to experimental or control using www.randomisation.com, and allocation concealment was performed with sequentially numbered, opaque, sealed envelopes. The experimental side received 850nm wavelength, 60mW/cm2 power, continuous LED with OrthoPulse device (Biolux Research Ltd, Vancouver, British Columbia, Canada) for 5min/d. For the control side, the device was blocked with opaque black film. Patients were reviewed at 4-week intervals for force reactivation and intraoral scanning over 12weeks. The primary outcome was the amount of tooth movement, and secondary outcomes were anchorage loss and canine rotation, all measured digitally. Blinding for study participants and the treating clinician was not possible; however, blinding was done for the measurements by deidentifying the digital scans. Linear mixed models were implemented for the data analysis. Nineteen participants concluded the study. Data analysis showed that the treatment×time interaction was not significant, suggesting no difference in space closure (unstandardized regression coefficient [b], 0.12; 95% confidence interval [CI], -0.05 to 0.29; P=0.17), canine rotation (b, 0.21; 95% CI, -0.82 to 1.25; P=0.69), and anchorage loss (b, -0.01, 95% CI, -0.28 to 0.26, P=0.94). No harms were noted. Daily 5-minute application of LED did not result in clinically meaningful differences during extraction space closure compared with no LED application. Australian New Zealand Clinical Trials Registry (ACTRN12616000652471). The protocol was not published before trial commencement. This research was funded by the Australian Society of Orthodontists Foundation for Research and Education.

Evaluation of interleukin-1 beta and the ratio of interleukin-1 beta to interleukin-1 receptor antagonist in gingival crevicular fluid during orthodontic canine retraction.

Orthodontic tooth movement (OTM) is a complex phenomenon mediated by cytokines, of which interleukin-1 beta (IL‑1β) is potently involved in the remodeling of the periodontal ligament (PDL) and bone. Whether the pattern of IL‑1β release differs at the sides of tension and compression is not yet clarified. The aim of the present study was to evaluate the level of IL‑1β and the ratio of IL‑1β to interleukin-1 receptor antagonist (IL‑1RA) in gingival crevicular fluid (GCF) at the tension and compression sides during orthodontic canine retraction. Seventeen patients scheduled for orthodontic treatment with bilateral extraction of maxillary first premolars and canine retraction were enrolled. Tooth 2.3 was retracted, teeth 1.3 and 3.3 served as controls. Gingival crevicular fluid samples were collected from the tension and compression sides of each tooth at baseline (before the 1st activation - day 0) and at days 2 and 7, and then again before the 2nd activation (day 28) and at days 30 and 35. The levels of IL‑1β and IL‑RA were evaluated with the enzyme-linked immunosorbent assay (ELISA). After the 1st activation, a statistically significant increase in the level of IL‑1β was observed at teeth 2.3 (p < 0.03 mesially and p < 0.05 distally) and 1.3 (p < 0.05 mesially and distally), both at the tension and compression sides. The 2nd activation resulted in a gradual increase in the IL‑1β level at both canines; however, statistical significance was reached only for tooth 2.3 (p < 0.05 mesially and p < 0.02 distally). In terms of the IL‑1β/IL‑1RA ratio, a significant increase was observed only at the compression side of the experimental tooth (p < 0.01). An increase in the IL‑1β level in GCF was observed both at the tension and compression sides of the actively retracted canine 2.3 as well as the contralateral canine 1.3; a significant rise in the IL‑1β/IL‑1RA ratio was noted only at the compression side of the experimental tooth 2.3, indicating the zone of active bone resorption.

Three-dimensional evaluation of the effects of injectable platelet rich fibrin (i-PRF) on alveolar bone and root length during orthodontic treatment: a randomized split mouth trial

BackgroundThe role of injectable platelet rich fibrin (i-PRF) in orthodontic treatment has not been investigated with focus on its effect on dental and bony periodontal elements.ObjectiveTo evaluate the efficacy of i-PRF in bone preservation and prevention of root resorption.MethodsA randomized split-mouth controlled trial included 21 patients aged 16–28 years (20.85 ± 3.85), who were treated for Class II malocclusion with the extraction of the maxillary first premolars. Right and left sides were randomly allocated to either experimental treated with i-PRF or control sides. After the leveling and alignment phase, the canines were retracted with 150gm forces. The i-PRF was prepared from the blood of each patient following a precise protocol, then injected immediately before canine retraction on the buccal and palatal aspects of the extraction sites. Localized maxillary cone beam computed tomography scans were taken before and after canine retraction to measure alveolar bone height and thickness and canine root length (indicative of root resorption), and the presence of dehiscence and fenestration. Paired sample t-tests and Wilcoxon signed rank tests were used to compare the changes between groups.ResultsNo statistically significant differences in bone height, bone thickness were found between sides and between pre- and post-retraction period. However, root length was reduced post retraction but did not differ between sides. In both groups, postoperative dehiscence was observed buccally and palatally and fenestrations were recorded on only the buccal aspect.ConclusionsI-PRF did not affect bone quality during canine retraction or prevent canine root resorption. I-PRF did not reduce the prevalence of dehiscence and fenestration.Trial registration ClinicalTrials.gov (identifier number: NCT 03399760. 16/01/2018).

Effect of photobiomodulation on external root resorption during orthodontic tooth movement – a randomized controlled trial

The objective of the study was to compare external root resorption during orthodontic tooth movement between patients who were subjected to photobiomodulation and those who were not. The study was designed as a split-mouth, single-blind randomized controlled trial conducted on twenty-two orthodontic patients requiring extraction of maxillary first premolars (age group 13-30years). A buccal force was applied to all the premolars using a 0.019″×0.025″ beta-titanium cantilever spring for 28days. The test group premolars were irradiated by indium-gallium-arsenide (InGaAs) diode laser (980nm, 100mW) 0, 3, 7, 11, 15 and 28days after force application. Each premolar was irradiated at ten locations on the buccal and palatal gingiva resulting in a total energy of 10J delivered per tooth. After 28days, the root surface of all the premolars were studied for the number and volume of resorption craters using three-dimensional optical profilometry by a blinded assessor. One-sample Kolmogorov-Smirnov test was used to ascertain normality and Mann-Whitney U test was applied for data analysis. All twenty-two patients enrolled completed the study. The root surface analysis showed formation of 32.78% less number of resorption craters (P<0.05) and 39.49% less volume of resorption craters (P<0.05) in the test group premolars relative to the control group premolars. The results of the present study, therefore, suggest that photobiomodulation reduces external root resorption during orthodontic tooth movement. CTRI/2018/04/013520.

Effect of injectable platelet-rich fibrin (i-PRF) on the rate of tooth movement.

To evaluate the efficiency of injectable platelet-rich fibrin (i-PRF) in accelerating canine tooth movement and to examine levels of the matrix metalloproteinase-8 (MMP-8), interleukin-1β (IL-1β), receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand (RANKL), and osteoprotegerin (OPG) in the gingival crevicular fluid during orthodontic treatment. Twenty patients (mean age = 21.4 ± 2.9 years) with Class II Division 1 malocclusion were included in a split-mouth study. The treatment plan for all patients was extraction of maxillary first premolars followed by canine distalization with closed-coil springs using 150 g of force on each side. The study group received i-PRF two times, with a 2-week interval, on one side of the maxilla. The contralateral side served as the control and did not receive i-PRF. Maxillary canine tooth movement was measured at five time points (T1-T5) on each side. Also, the activity of inflammatory cytokines was evaluated at three time points in the gingival crevicular fluid samples. There was a significant difference in canine tooth movement between the two groups (P < .001). i-PRF significantly increased the rate of tooth movement, and stimulation in the levels of inflammatory cytokines supported this result (P < .001). The levels of cytokines changed in both groups between T1 and T2. The IL-1β, MMP8, and RANKL values were significantly increased in the study group compared with the control group, while the OPG values were significantly decreased. i-PRF-facilitated orthodontics is an effective and safe treatment modality to accelerate tooth movement, and this method can help shorten orthodontic treatment duration.