Retraction Of Maxillary Anterior Teeth Research Articles

Friction versus frictionless mechanics during maxillary en-masse retraction in adult patients with Class I bimaxillary dentoalveolar protrusion: a randomized clinical trial.

Extraction space closure is a challenging phase during orthodontic treatment that affects not only the total treatment duration but also the whole treatment outcome. To compare the efficiency of friction and frictionless mechanics during en-masse retraction of maxillary anterior teeth in adult patients with bimaxillary dentoalveolar protrusion. Two-arm parallel group, single-center randomized clinical trial. Thirty-two adult patients with bimaxillary protrusion were recruited and randomly allocated to two different retraction mechanics. A friction group, using NiTi coil springs and a frictionless group using closing T-loops for en-masse retraction. Randomization in a 1:1 ratio was generated by Microsoft Excel. The randomization numbers were secured in opaque sealed envelopes for allocation concealment. Retraction started in all patients following first premolars extraction using miniscrews as a source of indirect anchorage. Activation was done on a monthly basis until complete retraction of anterior segment. The rate of retraction, amount of anchorage loss, the dental, and soft tissue changes were analyzed on digital models and lateral cephalograms taken before retraction and after space closure. The outcome assessor was blinded through data concealment during assessment. Two patients were lost to follow up, so 30 patients completed the trial. The rate of anterior segment retraction was 0.88 ± 0.66mm/month in the frictionless group compared to 0.72 ± 0.36mm/month in the friction group which was statistically significant. Anchorage loss of 1.18 ± 0.72mm in the friction group compared to 1.29 ± 0.55 mm in the frictionless group with no significant difference. Comparable dental and soft tissue changes following en-masse retraction were reported in both groups, with no statistically significant difference. one patient complained of soft tissue swelling following miniscrew insertion, but the swelling disappeared after one week of using mouth wash. The study focused only on the maxillary arch. Both mechanics have successfully achieved the required treatment objectives in patients with bimaxillary dentoalveolar protrusion. Frictionless group showed a faster rate of retraction than the friction group, which was statistically but not clinically significant. Clinicaltrials.gov with the identifier NCT03261024.

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

Comparative evaluation of effectiveness of three versus four mini-implants for simultaneous intrusion and retraction of maxillary anterior teeth: A 3D FEM study.

To evaluate and compare the displacement pattern of maxillary anterior teeth in the sagittal and vertical planes and evaluate the stress distribution in pdl, bone, teeth of the maxillary anterior region, and around the mini-implants during simultaneous en-masse retraction and intrusion using two, three, and four mini-implants combinations. A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with extracted first premolarswasgenerated. The models were broadly divided into three groups according to the number of mini-implants. Mini-implants were placed bilaterally between the second premolar and molar in group I, and along with bilateral implants, an additional mid-implant was placed between the central incisors as in group II, whereas in group III, anterior mini-implants were placed in between lateral incisors and canine bilaterally. The two mini-implant model showed the maximum amount of retraction in the sagittal plane followed by three and four mini-implant models. In the vertical plane, all six anterior teeth showed intrusion only in the four mini-implant model. The stress in cortical bone, cancellous bone, PDL, around the mini-implants, and in lateral incisor was maximum in the three mini-implant model, followed by four mini-implants with the least stress in the two mini-implant model. The four mini-implant model is better than the three and two mini-implants model as there is a more even distribution of force in the four mini-implants model as compared to the three mini-implants model.

Success rate of infrazygomatic crest mini-implants used for en-masse retraction of maxillary anterior teeth in first premolar extraction cases: A three-dimensional comparative prospective clinical trial between adolescents and young adults.

The purpose of this study was to compare the success rate of infrazygomatic mini-implants between adolescents and young adults. A total of 60 subjects of different age groups ie, (group I [adolescents]: 12-18 years, mean age: 14.9 ± 2.9 years; group II [young adults]: 19-25 years, mean age=21.9 ± 3.1 years) were assessed in the study. En-masse retraction of maxillary anterior teeth was carried out with extraction of upper first premolars with infrazygomatic crest (IZC) mini-implants as anchorage units. Clinical parameters such as success rate, soft tissue thickness, maximum insertion torque, maximum removal torque, pain response, soft tissue response, and cone-beam computed tomography parameters such as embedded angulation, penetration depth, thickness of bone on buccal and palatal aspect of mini-implant, and peri-implant bone density were evaluated. The success rate of IZC mini-implants in adolescents was found to be 96.6% and 98.3% in young adults respectively. There was no significant difference in success rate between the two groups. Intergroup comparison showed a significant difference (P < 0.05) in terms of maximum insertion torque, maximum removal torque, soft tissue thickness, cortical bone thickness, and peri-implant bone density values. Comparison between right and left side revealed a significant difference (P < 0.05) with regards to soft tissue response, soft tissue thickness, total bone thickness, cortical bone thickness, and peri-implant bone density. There was no significant difference in the success rate of IZC mini-implants between adolescents and young adults. Thus, the use of IZC mini-implants can be recommended in adolescents for successful orthodontic treatment.

Lever arm on bracket vs. lever arm on archwire: A 3D finite element method study of mechanics of miniscrew-supported lingual en-masse retraction of maxillary anterior teeth

To compare the deformation of the main archwire and 3D movements of maxillary anterior teeth during miniscrew-supported en-masse retraction with the lever arm on the archwire and on the brackets in lingual orthodontic treatment in finite element analysis (FEM) simulation. A 3D dental-alveolar model with bonded 0.018×0.025-inch slot lingual brackets and a 0.017×0.025-inch dimension stainless-steel archwire was created. Four FEM models were created based on a 3D dental-alveolar model: in Models A and C, the lever arms were attached to the lingual bracket, while in Models B and D, the lever arms were attached to the archwire. Meanwhile, in Models A and B, the miniscrews were placed in between the molars, while in Models C and D, the miniscrews were positioned on the palatal roof. After a 1.5N retraction force was applied from the miniscrew to the end of the lever arm, the initial movements in the sagittal, transversal, and vertical planes were recorded and analysed for maxillary anterior teeth. In Models B and D, smaller deformation of the main archwire and less prominent bowing effect were noticed in both sagittal and vertical directions compared to their counter groups. In Models C and D, the central incisors showed less torque loss in the sagittal direction and more canine intrusion vertically. For the same lever arm-miniscrew retraction configuration, the lever arm on the bracket showed less deformation of the main archwire and more body movement of the teeth than the lever arm on the archwire group. With the same level arm height, the transverse and vertical bowing effect is reduced when the lever arm was placed distal to the central incisor and the miniscrews placed next to the palatal suture.

Comparative Evaluation of Orthodontically-Induced Root Resorption Using Cone Beam Computed Tomography (CBCT) and Orthopantomogram (OPG) During En-Masse Retraction of Maxillary Anterior Teeth.

Orthodontically induced apical root resorption is an inescapable consequence of fixed orthodontics. This root resorption causes post-orthodontic complications in some treated cases. To avoid these complications proper diagnosis of the site and amount of resorption is important. The aim of this study was to compare the diagnostic ability of Orthopantomogram (OPG) and Cone Beam Computed Tomography (CBCT) in detecting apical root resorption after en-masse retraction of maxillary anterior teeth in a sample of Saudi Arabian population. The study sample comprised of 30 patients diagnosed with bimaxillary dentoalveolar protrusion. The treatment plan involved extraction of all first premolars followed by en-masse retraction of the anterior teeth. OPG images were obtained at the beginning of treatment and after the end of the retraction phase and a CBCT image were also obtained for the same patient at the same centre other than orthodontic reason like implant placement, temporomandibular joint (TMJ) problems, sleep apnea, etc. after orthodontic treatment completion. The scoring system of Levander and Malmgren was used to assess the degree and severity of root resorption in the maxillary incisors. Dalhbergs error and coefficient of reliability (ICC) were used to calculate the correlation between the two sets of readings.Pearson chi-square test was used to compare the difference in root resorption between OPG and CBCT images. A P-value of <0.05 was considered to be statistically significant. No resorption was observed in 39.2%and 16.6% of incisors with OPG and CBCT respectively. Mild resorption was observed in 50% and 66.7% of incisors with OPG and CBCT respectively. Moderate resorption was found in 10% and 15% of incisors with OPG and CBCT respectively. Severe root resorption was found in 0.8% and 1.7% of incisors with OPG and CBCT respectively. Statistically, significant differences were found in both methods of evaluation in all grades of root resorption for all the maxillary incisors (P<0.05). OPG had consistently underestimated the amount of orthodontically induced apical root resorption when compared to CBCT. OPG is only useful for the primary evaluation of root resorption. CBCT can be used as an adjunct diagnostic tool on a case-to-case basis in patients with moderate to severe root resorption to manage post-orthodontic treatment complications.

Evaluation of Stress Distribution of Maxillary Anterior Segment during en Masse Retraction Using Posterior Mini Screw: A Finite Element Study

The current study aimed to perceive and estimate the distribution of stress generated by the forces on the maxillary anterior teeth during orthodontic retraction using the bilateral mini screw implant. Finite element models were generated from the three-dimensional (3D) reconstruction of the maxillary arch via cone–beam computed tomography (CBCT). These models imitate the retraction of maxillary anterior teeth with the mini screw placed as the skeletal anchorage. The titanium mini screw of 1.3 mm × 8 mm dimension was placed at a height of 9 mm between the first molar and second premolar on both sides of the maxilla. A nickel titanium (NiTi) coil spring of 9 mm length was attached from the mini screw implant to the power arm which generated a force of 250 gm/side. Two different power arms were placed between the lateral incisor and canine at a height of 4 mm (group 1) and 8 mm (group 2), respectively. There were no significant differences observed when the stress values were compared to the left side and the right side in group 1 with a power arm of 4 mm. In group 2, the stresses around the lateral incisors were found to be on the higher side when compared with the central incisors and canines. The length of the power arm shows no significant difference in stress distribution pattern on the left and right sides except for stresses moving from the canine region to the lateral incisor region with the increase in power arm height.

In Vivo Comparison of the Efficiency of En-Masse Retraction Using Temporary Anchorage Devices With and Without Orthodontic Appliances on the Posterior Teeth.

To compare the effectiveness of en-masse retraction of maxillary anterior teeth using temporary anchorage devices with and without orthodontic appliances on the posterior teeth. In the study, 20 participants (18.25 ± 4.07 years) meeting the inclusion criteria were randomly divided into 2 groups using the sequentially numbered opaque sealed envelopes method. In group I (control group, n = 10), en-masse retraction was carried out with conventional high hooks soldered to the retraction wire and posterior teeth were included. In group II (experimental group, n = 10), the en-masse retraction was carried out without an orthodontic appliance on posterior teeth and a modified retraction wire was incorporated. In both groups, mini-implants were placed bilaterally between the maxillary second premolar and maxillary first molar, and a retraction force of 6 ounces (180 g) was applied using power chains. Lateral cephalograms and study models were taken before retraction and 4 months after retraction. All statistical analyses were performed with Statistical Package for the Social Sciences soft- ware with a statistically significant level of 5%. We used unpaired t-tests for the comparison, and the error of the method was assessed using intraclass correlation coefficients and the Bland-Altman method. The maxillary incisor apex retraction, change in maxillary incisor in the vertical plane, and its inclination showed statistically significant differences (P < .05). The rate of retraction was significantly greater in the experimental group when evaluated clinically and in the study models (P < .05). The rate/amount of retraction evaluated clinically and in the study models was significantly faster/greater when the pos- terior teeth were not included during anterior retraction. Also, a greater amount of bodily retraction of anterior teeth was achieved.

Efficacy and safety of piezocision in accelerating maxillary anterior teeth en-masse retraction: study protocol for a randomized controlled trial

BackgroundOrthodontic treatment is commonly more time-consuming in adults than in teenagers, especially when it comes to the maxillary en-masse retraction, which may take 9 months or even longer. As to solve this concern, orthodontists have been striving to seek new methods for shortening orthodontic treatment time. Piezocision, as a popular alternative treatment, has been widely used in different types of tooth movement. However, its effect on en-masse retraction of maxillary anterior teeth remains unclear. This randomized controlled trial intends to figure out the role piezocision plays in accelerating en-masse retraction.MethodsThis protocol is designed for a prospective, single-center, assessor-blinded and parallel-group randomized controlled trial. Twenty adult patients aged from 18 to 40 whose orthodontic treatment required bilateral maxillary first premolars extraction will be randomly assigned to the piezocision group and the control group at a ratio of 1:1. The piezocision group will undergo en-masse retraction immediately after the piezo surgery, while the control group will start en-masse retraction directly. Both groups will be followed up every 2 weeks to maintain the retraction force until the end of space closure. The space closing time is set as the primary endpoint. Meanwhile, the secondary endpoints include the change of root length, labial and palatal alveolar bone thickness, vertical bone height, probing depth of maxillary anterior teeth, cephalometric measurements, visual analogue scale, and postoperative satisfaction questionnaire.DiscussionThis study will attempt to provide more convincing evidence to verify whether piezocision will shorten the time of en-masse retraction or not. Distinguished with previous studies, our study has made some innovations in orthodontic procedure and primary outcome measurement, aiming to clarify the efficacy and safety of piezocision-assisted en-masse retraction in Chinese population.Trial registrationChinese Clinical Trial Registry ChiCTR 1900024297. Registered on 5 July 2019

En-Mass Retraction of Maxillary Anterior Teeth with Severe Proclination and Root Resorption—A Case Report

Molar distalization has been a validated method to correct dental sagittal relationships and create space to relieve mild to moderate crowding. In the current case report, an adult female patient had a mild skeletal Class III relationship and dental Class III molar relationship. Four premolars and one lower incisor were extracted during the previous two rounds of orthodontic treatments, and the maxillary anterior teeth were left with severe proclination and root resorption. Limited by the available teeth, extraction was not an option for her. Thus, molar distalization with TADs was the best option used in the treatment to address her chief complaint. In addition, a proper bite opening was performed to eliminate occlusion trauma. Utilizing the mid-palatal TADs, the maxillary central incisors were retracted 7.9 mm and retroclined 33 degrees, and the molar distalization was achieved as much as 8 mm. The cross-section slices of CBCT images confirmed the proper retraction of maxillary incisors and well-positioned roots in the alveolar bone. Moreover, the root resorption was not worsened from the treatment. Clinically, the maxillary anterior teeth were preserved esthetically and functionally. This case report illustrates that with proper diagnosis and treatment mechanics, significant tooth movement can be achieved even on extremely proclined maxillary incisors with severe root resorption.

Efficacy of various multi-layers of orthodontic clear aligners: a simulated study

Background: In the invisible orthodontic treatment, composite thermoforming film materials have become the focus of orthodontic clear aligners. The orthodontic efficacy of clear aligners which consisted of multi-layers materials remains unclear. This study aims to evaluate the biomechanical effects of various multi-layers of clear aligners on en-mass retraction of maxillary anterior teeth. Methods: A patient-specific 3D non-linear finite element model numerical analysis was constructed to simulate the en-mass retraction of maxillary anterior teeth with clear aligner after extraction of the first premolars. Four kinds of multi-layers clear aligners with different proportion of film materials were simulated. The biomechanical responses of four different clear aligners on invisible orthodontics were calculated. The tooth displacement in all directions, the hydrostatic pressure of periodontal ligament, the orthodontic deformation of clear aligner, and the stress distribution of alveolar bone were compared and investigated. Results: In all experimental models, the maximum equivalent deformation of alveolar bone, the vector displacement of tooth and the compressive/tensile stress of periodontal ligament decreased with the increase of soft layer thickness. The elastic strain of clear aligners also decreased with the increase of the ratio of soft/hard layers. Conclusions: The multi-layers clear aligner is better than the single-layer clear aligner in tooth movement, stress distribution of periodontal ligament and mechanical loading of alveolar bone, especially when the ratio of soft layer to hard layer is more than 50%. Moreover, the side effects of the multi-layers clear aligner are significantly less than those of the single-layer one.

Dental arch and Smile Changes Following Miniscrew Anchored En-masse Retraction of Anterior Teeth in Class II Division 1 Malocclusion

Objective: to evaluate dental arch and smile changes after miniscrew anchored en-masse retraction of maxillary anterior teeth in Class II division 1 malocclusion cases. Methods: A total of 22 adult patients (mean age, 19.78 + 1.24 years) with Class II division 1 malocclusion were randomly assigned to 2 groups; group I (11 patients treated with miniscrew anchored en-masse retraction) and group II (11 patients treated with two-step retraction using conventional anchorage). Skeletal, dentoalveolar and smile changes were analyzed in both groups using standardized photographs, study casts, and lateral cephalograms before and after space closure. Results: Miniscrew anchored en-masse retraction showed a statistically significant decrease in upper incisor display (U1UL) (-2.22±1.33; P 0.05). Group II demonstrated a statistically significant decrease in IMW (-1.63 ± 1.19, P<0.05) and significant mesialization of maxillary first molars (U6-MR, U6-LR) (-2.46 +1.64, -1.03 + 1.13, P˂0.05). Conclusion: The use of miniscrews as a means of anchorage during retraction of maxillary anterior teeth provides an absolute anchorage for maxillary first molars with in either anteroposterior or vertical direction. Therefore, it could effectively reduce upper incisors display without altering buccal corridor dimensions or affecting the smile arc.

Evaluation of Orthodontic Mini-implant-anchored en masse Retraction of Maxillary Anterior Teeth with Reduced Bone Support: A Prospective Finite Element Analysis Study

The purpose of this study was to evaluate force systems to bring about the en masse retraction of maxillary anterior teeth having reduced bone levels using finite element analysis. This is a prospective study. Three-dimensional finite element models of maxillary dentition having normal alveolar bone level and 2, 4, and 6 mm bone loss with first premolar extraction were constructed from a spiral CT scan of a skull. Archwire and brackets were modeled on the facial surfaces of teeth. Retraction force of 175 gm was applied from an orthodontic mini-implant placed bilaterally between the second premolar and first molar and 12 mm above plane of the archwire to anterior retraction hook (ARH) fixed at two heights of 6 and 10 mm above the archwire. Maximum displacement and periodontal ligament (PDL) stress were calculated for different combinations of bone levels and ARH. As the bone loss increased, the tipping tendency, amount of intrusion, and maximum von Mises stress in PDL also increased, showing a direct correlation. To minimize tipping and PDL stress, the height of ARH should be increased in alveolar bone loss conditions to allow retraction force to pass through or even above the center of resistance of anterior teeth. Even then, pure bodily retraction may not be achieved, but tipping tendency can be reduced. Nevertheless, it may not be suitable to increase ARH beyond a limit owing to chances of irritation to the vestibular mucosa. Alternative methods should be contemplated to reduce the tipping behavior. The alternative is to apply a lighter retraction force to reduce lingual tipping. A higher counter-moment in the archwire or bracket can also be incorporated.

En-masse intrusion and retraction with preadjusted edgewise appliance using two different sites of mini-implant placement

This article compares the treatment outcome between two patients when en-masse intrusion and retraction of the maxillary anterior teeth were performed with mini-implants placed at different sites. Both the patients had a skeletal Class II malocclusion with Angle's Class I molar relation, Class I canine relation, proclination of upper and lower anterior teeth. In the first case, intrusion and retraction was done with conventional friction mechanics for space closure and an intrusive force from a mini-implant placed in the midline. In the second case, intrusion and retraction were done with the application of force from the anterior attachments to mini-implants placed between the second premolars and first permanent molar bilaterally. There was intrusion of the maxillary anterior teeth with both mechanics. However, the evaluation of treatment outcome at the end of space closure showed mesial movement of the maxillary first permanent molar in the first case. In the second case, distal movement and intrusion of the maxillary first permanent molar and decrease in the lower anterior facial height was noted. The mechanics in the first case can be applied for intrusion and retraction of maxillary anterior teeth when anchorage requirement is not critical. The mechanics described in the second case can be used for intrusion and retraction of maxillary anterior teeth in cases with a very high anchorage need and will be beneficial in patients with vertical growth pattern.

Three-Dimensional Finite Element Analysis for Stress Distribution During Intrusion and Retraction Using Orthodontic Mini-implants

Background and Objectives: the study was conducted to evaluate the levels of stress produced in and around implants when placed at different sites for retraction and intrusion of maxillary anteriors. The other objective was to evaluate stress levels produced at implant bone interface when mini implants were placed at different angulations at the same site. Materials and Methodology: Finite element model of the maxilla and maxillary dentition was constructed using the CT skull of subject used in the study. All the accessories used like mini-implants, stainless steel wire, coil springs etc were scanned separately for obtaining detailed anatomic features. The force was given between retraction hook and mini -implant using NITI closed coil spring for intrusion and retraction of maxillary anterior teeth. The basic mechanical factors i.e. the stresses developed in mini implant, the angle of insertion of the mini implant into the bone surface were analyzed. Finite Element model was generated by Hyper mesh 9.0 software. Analysis was carried out by using Ansys 12.1 software. Results and Conclusion: All the set objectives were accomplished at the end of the study which included complete closure of extraction space by retraction and intrusion in the models. The following conclusions were drawn: The least stress was seen on an implant at middle third, when inserted at an angle of 800 to the bone surface, with application of 50-100mg of intrusive force on anterior implant and 200 gms of retractive force on posterior implant.

The effectiveness of traditional corticotomy vs flapless corticotomy in miniscrew-supported en-masse retraction of maxillary anterior teeth in patients with Class II Division 1 malocclusion: A single-centered, randomized controlled clinical trial

This single-centered, parallel-groups trial aimed to evaluate the efficacy of traditional corticotomy vs flapless corticotomy in accelerating en-masse retraction. In addition, to assess the skeletal, dental, and soft-tissue variables, as well as the external apical root resorption (EARR) of the maxillary anterior teeth. Forty patients with Class II Division 1 malocclusion aged>18years at the beginning of treatment, requiring maxillary first premolar extractions, were randomly distributed into 2 groups (n=20 each): 1 group was treated using traditional corticotomy, and the other group was treated with flapless corticotomy in en-masse retraction with anchorage based on miniscrews placed between maxillary second premolars and first molars bilaterally. Randomization was implemented with a computer-generated list of random numbers; allocation was concealed in sequentially numbered, opaque, sealed envelopes. The study was single-blinded (outcomes' assessor). The primary outcome was the en-masse retraction duration. Secondary outcomes were the skeletal, dental, and soft-tissue changes on lateral cephalometric and the EARR of maxillary anterior teeth on digital panoramic radiographs. The en-masse retraction duration in the flapless corticotomy group was longer than the traditional corticotomy group. The average retraction duration was 4.04±1.10months for the flapless corticotomy group and 3.75±2.14months for the traditional corticotomy group, with no significant difference between the 2 groups (95% confidence interval [CI], -0.81 to 1.39; P=0.59). No significant differences were observed between the 2 groups regarding changes in several lateral cephalometric variables (eg, SNA angle [95% CI, -2.55° to 1.66°; P=0.67], SN-U1angle [95% CI, -1.70° to 1.32°; P=0.80], and UL-E [95% CI: -1.33 to 1.00mm; P=0.78]) or in the amount of EARR in the maxillary anterior teeth (P=0.31). The proportion of the observed EARR ranged from 1% to 6% of root length in both corticotomy groups. No serious harms were observed in both groups. No significant differences between the flapless and traditional corticotomies were found in terms of the skeletal, dental, and soft-tissue variables as well as in the amount of EARR. Corticotomy-assisted en-masse retraction led to improvements in skeletal structures and facial profile and resulted in sufficient retraction of maxillary anterior teeth, slight distal movement of maxillary first molars, and an intrusion movement for both anterior and posterior teeth. Both corticotomy techniques did not cause significant EARR. ClinicalTrials.gov (Identifier: NCT03279042). The protocol was not published before the trial commencement.

Comparison of the Anchorage Value of the First Molars Supported with Implant and First Molars Supported with Second Molar during En Masse Retraction.

Aims and Objectives:The aim of this study was to determine the efficacy of mini-implants as adjuncts for intraoral anchorage units for en masse retraction of maxillary anterior teeth in bimaxillary dentoalveolar protrusion cases.Materials and Methods:The study sample consisted of 15 patients (10 females and 5 males). The samples were compared for anchorage loss with the implant-supported molar and conventional molar contralaterally in both the maxilla and mandible after six months of retraction period. The mini-implants used were 1.5 mm in diameter and 8 mm in length and were inserted in the first and third quadrant between the roots of second premolar and first molar under local anesthesia at an angle of 45°. For en masse retraction, active tiebacks with ligating (100g) were used bilaterally extending from molar hooks to J-hook on a 0.019” × 0.025” stainless steel arch wire. Lateral cephalograms were taken before and after retraction for assessing the loss of anchorage in maxillary and mandibular first molars.Results:Anchorage loss of 1.46 mm in the maxilla and 1.36 mm in mandible was found with conventional molar anchorage, whereas no statistically significant anchorage loss was found in the implant-supported molar side.Conclusion:Implant-supported molar side showed better anchorage compared with the conventional molar side. Hence, implant-supported molar can be used as an absolute anchorage unit in the en masse retraction of anterior teeth.

Comparing the Clinical Success Rate of Self-Drilling and Self-Tapping Mini-screws in the Retraction of Maxillary Anterior Teeth

Objective: To compare the success of self-drilling and self-tapping methods in the retraction of maxillary anterior teeth. Material and Methods: The study was conducted in 57 subjects with Cl II malocclusion who needed to be treated with extraction of four maxillary teeth. The self-tapping method was used on the left side and the self-drilling method was used on the right side. Then, the pain rate of each method was recorded by the numerical rating scale (NRS). Statistical analysis was done by t-test and Chi-square test. The significance level in this study was considered at p-value 0.05). There was a significant difference between the groups (p=0.03). The pain was significantly higher in the female. Conclusion: There is no difference between self-drilling and self-tapping methods in terms of success. Comparison of the pain between two genders according to the replantation method showed a significant difference in pain sensation between two genders. The pain sensation mean in female group was greater than male group.

En-masse Retraction of Upper Anterior Teeth in Adult Patients with Maxillary or Bimaxillary Dentoalveolar Protrusion: A Systematic Review and Meta-analysis

To evaluate the efficacy of accelerated and non-accelerated methods of en-masse retraction of the upper anterior teeth in terms of skeletal, dental, and soft-tissue variables, as well as the duration of retraction or overall orthodontic treatment. An electronic search of PubMed and nine other major databases for randomized controlled trials (RCTs) and clinical controlled trials (CCTs) was performed between January 1990 and April 2018. The bibliography in each identified article was reviewed. In addition, manual searching was performed in the same time frame in five major orthodontic journals.The participants were patients over 14 years old undergoing fixed orthodontic treatment with extraction of maxillary or bimaxillary premolars followed by en-masse retraction of maxillary anterior teeth in both groups. Cochrane's risk of bias tool for RCTs and methodological index for non-randomized studies (MINORS) for CCTs were used. Eight articles (six RCTs and two CCTs) were included in this review, and only five articles were suitable for quantitative synthesis. The en-masse retraction caused a decrease in the SNA and ANB angles with no significant differences between the different en-masse retraction methods. Using temporary skeletal anchorage devices (TSADs) gave significantly better results in terms of posterior anchorage in comparison with conventional anchorage(standardized mean difference (SMD) = -3.03 mm, p < 0.001). No significant difference was found between en-masse/flapless corticotomy and en-masse/control groups in terms of anterior teeth retraction (p = 0.661); while there was a significantly greater anterior teeth retraction in corticotomy with flap elevation group compared to control group (p < 0.001). There is a weak to moderate evidence that using accelerated and non-accelerated methods would improve the facial profile and lead to similar skeletal corrections. There is weak to moderate evidence that using TSADs would lead to better posterior anchorage than using conventional anchor-age.Moderate evidence was found regarding the benefit of using piezosurgery in achieving good incisors' inclination. Contradictory results were found regarding the amount of achieved anterior retraction and the retraction time in the studies that evaluated acceleration methods versus the traditional methods of retraction. According to the quality of evidence, there is a need for more well-conducted RCTs, and more work to be oriented towards en-masse retraction with the use of other acceleration methods. The correction of the maxillary or bimaxillary dentoalveolar protrusion by en-masse retraction of the upper anterior teeth with/without acceleration is accompanied by aesthetic results in the facial soft tissues as well as in the underlying skeletal and dental structures. The traditional corticotomy-assisted retraction is expected to reduce the retraction time significantly. However, the strength of evidence is not strong and requires additional research work.

Management of Type I Talon's Cusp Using Cone Beamed Computed Tomography as a Diagnostic Aid: A Case Report

Talon's cusp is an uncommon developmental anomaly that frequently creates an occlusal interference resulting in occlusal trauma, premature contact or reversible apical periodontitis of the opposing tooth. Such occlusal interference is commonly encountered during orthodontic treatment while retraction of maxillary anterior teeth. Advanced diagnostic tools like CBCT is useful for exploring the details of endodontic architecture. The present case revealed bilateral existence of talon's cusp on the palatal aspect of maxillary lateral incisors interfering with the bite during orthodontic treatment. With the use of CBCT as a diagnostic aid, this case was managed using a minimally invasive approach with greater patient comfort.