Lingual Arch Research Articles

Antimicrobial properties of glass-ionomer cement incorporated with zinc oxide nanoparticles against mutans streptococci and lactobacilli under orthodontic bands: An in vivo split-mouth study

Background: The aim of this study was to assess the effect of incorporation of zinc oxide nanoparticles (ZnO-NPs) to glass-ionomer cement (GIC) (Fuji II SC, GC Corp., Tokyo, Japan) on subgingival accumulation of mutans streptococci and lactobacilli under orthodontic bands.Materials and Methods: In order to conduct this in vivo split-mouth study, 20 patients aged between 7 and 10 years who required lingual holding arch on their mandibular first molars were divided into two groups. In one group, Fuji II SC GIC was used for cementation of the right molar band, and the same cement containing 2 wt% ZnO-NPs was used for the left one. The opposite was performed for the second group while the operator was blinded to the cement types. Subgingival microbial sampling was performed 16 weeks after cementation of lingual arch. Mutans streptococci and lactobacilli colony counts were compared. Paired t-test was used to compare the two cement groups. Data were analyzed using SPSS version 21, and P ≤ 0.05 was considered statistically significant.Results: The mean colony counts of mutans streptococci, lactobacilli, and total bacterial count in Fuji II SC containing ZnO-NPs were significantly lower than the corresponding values in plain Fuji II SC group.Conclusion: Incorporation of ZnO-NPs into GIC reveals antimicrobial features against mutans streptococci and lactobacilli under orthodontic bands.

Three-dimensional of lingual arch form and creation of templates in Iraqi normal occlusion.

To evaluate the lingual dental arch form types in class I canine and molar relationship based on scanning dental cast models using three-dimensional laser scan and to give a new lingual arch form pattern created on this classification to be used for clinical submission by studying three-dimensional virtual models of the normal occlusion samples. Maxillary and mandibular casts of 120 young adults (18-24 ± 1.84 years) have normal occlusion that was scanned using a 3Shape E1 laser scanner, and then, the data were analyzed using SPSS software; then, we used K-means cluster to classify the arch form into clusters depending on the measurement of 10 landmarks designated on the lingual surface of the teeth. Many dental arch patterns have been established for both the mandible and the maxilla. The minimum sizes were found in the females, and the biggest sizes were found in the male subjects, and three sets were well defined for each sex; three categories for each mandible and maxilla are as follows: narrow, mid, and broad. The lingual arch form can be classified into three groups based on posterior and anterior dimensions, so a template of the three arch forms has been exemplified.

Early orthodontic treatment in a Finnish public health centre: a retrospective cross-sectional study

Objectives The aim of this observational cross-sectional one-centre study was to assess whether the previously described national orthodontic treatment practises and international recommendations are implemented in a public health care centre in Finland. We also assessed early treatment practices and appliances used. Methods The study group comprised 801 children born in 2011 and 2012 residing in the Riihimäki health centre catchment area in Finland, representing 80% of the age cohort. The patient records were examined for data on orthodontic treatment, timing of treatment, appliances used, and occlusal traits. Results The children had been examined by four orthodontist specialists and two orthodontic postgraduate students. Mean age at occlusal examination had been 9 years. Of the children, 212 (26%) were undergoing or had undergone orthodontic treatment. An additional 4.4% were scheduled for treatment. The proportion of children deemed to need treatment was significantly different between the different orthodontists. The most frequently used appliances were quad-helix (30%), eruption guidance appliance (20%), head gear (14%), fixed appliances (10%), protraction facemask (10%), and passive mandibular lingual arch (6%). Conclusions Nearly one-third of children aged less than 12 years in the health centre were currently or had been in orthodontic treatment. Approximately half had received treatment with either quad-helix or eruption guidance appliance.

Evaluation of modified C-palatal plates on speech articulation using acoustic analysis.

The purpose of this study was to assess speech perturbation and adaptation for patients wearing modified C-palatal plates (MCPPs) over time. The sample consisted of 40 patients, 20 wearing MCPPs as the experimental group (age: 20.7± 5.8 years) and 20 patients wearing a transpalatal arch (TPA) as the control group (age: 21.5± 6.4 years). The sounds /t/, /d/, /s/, /n/, /r/, /tʃ/. and /j/ were recorded for each patient at six time points: immediately before (T0) and after (T1) appliance placement; then 1, 2, 3 and 4 weeks after placement (T2-T5). Acoustic analysis of pitch and voice onset time (VOT) was performed by Praat software. Repeated measures analysis of variance (RM-ANOVA) was used to assess changes in the pitch and VOT over time and the difference between the appliances. With the MCPP appliance, /n/, /r/, /tʃ/ and /j/ decreased in VOT starting in the first week while /t/ and /s/ almost returned to pre-treatment levels after 2 weeks. VOT for the /d/ sound did not change between T0 and T3, but it decreased after 3 weeks. There were no significant differences in pitch and VOT between the two groups at any time point. Wearing an MCPP device caused patients to initially distort the articulation of several sounds, but the distortion dissipated within 1 to 2 weeks. It is recommended that patients and/or their parents be advised during pre-treatment counselling of the possibility of temporary speech changes with MCPP placement.

Treatment of Palatally Displaced Canines Using Miniscrews for Direct or Indirect Anchorage: A Three-Dimensional Prospective Cohort Study on Tooth Movement Speed

Palatally impacted canines are usually challenging to treat in terms of both biomechanics and possible side effects. Different therapeutic approaches have been reported with or without the use of temporary anchorage devices, including the canine-first approach. Two groups of patients with palatally impacted canines were compared, observing their canine movement measured on consecutive CBCTs after three months of treatment. In the control group, impacted canines were treated with direct anchorage on miniscrews, and in the test group with indirect anchorage using a miniscrew-supported transpalatal arch. The primary outcome was the canine movement speed; the secondary outcome was the change in the root length of adjacent teeth. The median monthly apex speed was 1.05 mm in the control group (IR [0.74, 1.64]) and 0.72 mm in the test group (IR [0.27, 1.30]). The median monthly cusp displacement was 1.89 mm in the control group (IR [1.04, 2.84]) and 1.08 mm in the test group (IR [0.81, 1.91]). Approximately 50% of teeth adjacent to an impacted canine underwent a negative root length change of less than 1 mm in the majority of cases, but no significant differences were found in root length changes between groups. No statistically significant differences in the reported speeds were found, and no miniscrew failures were observed in either group.

Comparison of the effectiveness of butterfly arch versus transpalatal arch in anchorage reinforcement: A linear 3D finite element study.

Background. Although there are various intraoral and extraoral appliances for anchorage management in orthodontics, most fail to preserve the anchorage efficiently. Thus, there is a need for an appliance that can preserve anchorage in the sagittal, vertical, and transverse directions with good patience compliance and cost-effectiveness. This study compared the efficacy of butterfly arch and transpalatal arch (TPA) as an anchorage reinforcing unit during orthodontic space closure using a linear finite element model. Methods. A 3D model of the maxilla and associated structures was developed from CT images of an individual's skull at a slice thickness of 1 mm. The magnitude of movements of anchor teeth in vertical, horizontal, and transverse directions was calculated in first premolar extraction cases during anterior retraction using a linear finite element model analysis and compared in two situations-butterfly arch and TPA attached to maxillary first molar for anchorage. Results. The anterior teeth had similar movements in the case of TPA and butterfly arch. There was more mesial and lingual movement in the first molars with TPA than in the butterfly arch, which had buccal but no mesial movement. The anterior teeth showed extrusion and the second premolars showed intrusion with TPA. Also, the von Mises stress and maximum principal stress were maximum with TPA at the cervical region of anterior and posterior teeth compared to the butterfly arch, where both stresses were uniformly distributed all over the teeth. Conclusion. A butterfly arch with its unique design, configuration, and biomechanical properties can be used as a device that can maintain the posterior anchorage efficiently.

3D biomechanical intrusion effects of infra zygomatic bone screws and temporary anchorage device on total maxillary dentition in treatment of vertical maxillary excess: A FEM study

Many studies have reported on the application and clinical efficiency of full arch maxillary dentition intrusion mechanics; however, studies about biomechanical effects such as stress, strain, and displacements on the teeth and the surrounding tissues are limited. The objectives of study was to evaluate and compare the stress distribution and displacement of total maxillary dentition under intrusion mechanics using a three-dimensional finite element analysisA three-dimensional finite element model was constructed based on computed tomography scan data, and it served basic model. The geometric model was converted to finite element model using Altair HyperMesh software. Model A with pre-adjusted edgewise appliance (PEA) setup and Model B with occlusal Splint setup was evaluated and compared for von mises stress distribution and displacement of total (full arch) maxillary dentition by using three dimensional finite element analysis; with force delivered from infrazygomatic screws and miniscrew. Force levels for Model A and Model B includes a total of 300grams of intrusive force (each side) on maxillary posterior segment from IZC bone screw and 100grams of intrusive force on anterior segment from miniscrew.In the model A; with PEA setup reinforced with two trans-palatal arches, highest von Mises stress of 0.970 Mpa was produced on second molar roots followed by molar roots and premolars and central and lateral incisors roots. In the Model A, maximum intrusive values was seen on crown tip of central and lateral incisors (8.671µm), and lowest displacement values on second molars (2.230µm). Similar pattern of von Mises stress distribution and displacement was observed in the Model B. Model A and Model B provided an effective en masse vertical control of the full arch maxillary dentition. Higher intrusion displacement values were seen in anterior segment than the posterior segments

Dynamics, Efficacies, and Adverse Effects of Maxillary Full-Arch Intrusion Using Temporary Anchorage Devices (Miniscrews): A Finite Element Analysis.

Introduction Absolute anchorages obtained from temporary anchorage devices (TADs, miniscrews) considerably facilitate dental movements and make some very difficult movements such as full-arch intrusions possible. Despite the significance of assessing strategies to fully intrude the arch using mini-implants, there is no study in this regard except a few case reports. Therefore, we simulated/tested 4 scenarios. Methods Four maxilla models were created with different miniscrews/appliances: (1) two miniscrews were placed distal to laterals and one in the mid sagittal region. (2) Two mini-implants were inserted in mesial of canines and 2 others between bilateral first and second molars, plus another TAD in the midpalatal area, plus a transpalatal arch (TPA). (3) Two mini-implants were inserted between bilateral canines and first premolars and 2 others between bilateral first and second molars + TPA. (4) Two mini-implants were installed between lateral-and-canine and 2 miniscrews between second premolars and first molars + TPA. Intrusive forces (80 g anterior, 150 g posterior) were exerted using stainless-steel coil springs. Stresses/displacements were measured. Risk of external root resorption was evaluated. Results The highest amounts of incisor/molar intrusion were seen in model 1. Model 2 had fewer intrusions, but its control over undesired movements was greater. Model 4 drastically reduced molar intrusion and considerably increased premolar intrusion. Overall amounts of intrusion were highest in the first 2 models, marking them as proper candidates for cases needing greater intrusion extents. Model 2 may be useful when miniscrew loosening/failure is a concern, while model 1 is recommended when fewer miniscrews are allowed. Overall, the highest and lowest root resorptions might occur in models 1 and 4, respectively. Conclusions Each model showed certain efficacies/drawbacks and thus is recommended for a particular set of cases. Therefore, depending on the diagnosis and treatment plan, one or more of these scenarios might be desirable.

Orthodontic Treatment for Adult Patients with Scissors Bite Using Tiggle Brackets

Due to the difficulty of correcting scissors bite, so many treatment modalities have been suggested. One of them are crisscross elastics, orthodontic miniscrews, trans-palatal arch with precision lingual arch wire, and so on. Tiggle brackets are one of minitubes which was recently introduced for the treatment of anterior teeth. It is designed to be positioned on the lingual surfaces of the anterior teeth. They exert very light force, so the counteraction is very small with minimum side effect. With their small size, it is good to bond on the teeth with scissors bite, reducing the possibility of falling off during masticatory movement. Tiggle brackets can be a very useful orthodontic treatment modality when correcting scissors bite.

Occlusal Plane Changes after Maxillary Molar Distalization Using Temporary Skeletal Anchorages Devices: A Narrative Review and Preliminary Study

Background: We conducted a narrative review of studies analyzing the occlusal and mandibular plane angles after maxillary molar distalization using temporary skeletal anchorage devices (TADs). An original preliminary investigation was conducted on the occlusal and mandibular plane angle changes according to the design of TAD-supported distalization. Methods: We included 51 participants stratified into three groups (buccal TAD, lingual arch TAD, and pendulum TAD) who underwent lateral cephalography before and after treatment. The paired t-test and ANOVA were used to analyze the significant differences among the groups. Results: The pterygoid vertical to maxillary second molar (p < 0.01) significantly differed before and after treatment within each group (group 1, 1.29 ± 1.73 mm; group 2, 2.01 ± 1.46 mm; group 3, 1.12 ± 1.43 mm). The angle between the Frankfort horizontal and anatomical occlusal plane increased by 1.96 ± 2.88° (p < 0.05) and 2.51 ± 2.57° (p < 0.01) in groups 2 and 3, respectively. Conclusions: The measured variables did not significantly differ among the three groups. The Frankfort-mandibular plane angle and functional occlusal plane did not change after maxillary molar distalization. The anatomical occlusal plane is influenced by the anterior teeth and may be unrelated to maxillary molar distalization. Further studies are required to verify the exact relationship between maxillary molar distalization and occlusal plane angle.

Transpalatal Arch and its Modifications

Versatility has become key feature for an appliance to be chosen for any orthodontic treatment, one such appliance is transpalatal arch (TPA) which has numerous advantages while using in fixed orthodontic treatment. TPA not only provides additional anchorage but also used for active movement of individual teeth. The aim of this article is to present a broad review of the literature by including various modifications of TPA and their indications, to better assist the clinician for using it in different case

Effective approach for improving agummy smile : Upward movement of the maxillary occlusal plane using midpalatal miniscrews and amodified transpalatal arch.

Correction of agummy smile by orthodontic treatment alone has recently become feasible with the use of miniscrews. However, the optimal treatment mechanics remain unclear. Here we cephalometrically evaluated jaw and tooth displacement in cases where agummy smile was improved using alevel anchorage system (LAS). Sixteen patients underwent orthodontic treatment using anLAS consisting of amodified transpalatal arch and midpalatal miniscrews. Cephalometric pretreatment and posttreatment measurements were compared using the paired t‑test to determine significant skeletal and dental changes. The Mann-WhitneyU test was used for nonparametric data. Spearman's rank correlation coefficient was used to evaluate correlations between different variables and the vertical change in prosthion position which was used to indicate the amount of gingival exposure. The changes noted after treatment were intrusion of the maxillary first molars (P < 0.001) combined with only minor extrusion of the mandibular first molars. Suppressed extrusion of the mandibular first molars was significantly correlated with greater upward movement of the prosthion (r = 0.676, P < 0.01). Upward movement of the prosthion was also significantly correlated with intrusion of the maxillary and mandibular incisors, anterior upward movement of the maxillary occlusal plane, and an increase of the SNP angle. Treatment involving the combined use of miniscrews and amodified transpalatal arch resulted in intrusion of the maxillary first molars and maxillary incisors and consequently elevated the maxillary occlusal plane. The results of this study suggest that intruding the maxillary occlusal plane and minimizing mandibular molar extrusion were effective to induce autorotation of the mandible and to improve agummy smile.

The Application of a 3-Dimensional Printing Technique in Refining the Orthodontic Trans-Palatal Arch

The aim of this article was to describe the process of designing and manufacturing 3D TPAs and to discuss some clinical cases in which 3D TPAs were used. Digital models were acquired by scanning the casts, scanning the PVS impressions or scanning the dentitions directly. The scanning data in a common STL format was used for the computer design that follows. Then, the design instructions were sent to a 3D printer for fabrication. Finally, manual polishing should be performed. Seven clinical cases in which 3D TPAs were used to assist orthodontic treatment were presented and discussed. The presented clinical cases demonstrated that the 3D TPA was a simple, convenient appliance for the patient and the doctor, and thus, might be more cleansable. The 3D TPA could be designed in different types based on the clinical needs of each case. The application of 3D TPA could be expanded, but clinical trials are necessary to verify the advantages reported here.

A Scoping Review on Design Modifications of Lingual Holing Arch appliance

Background: Lingual holding arch appliance has been the most trusted space maintainer in the field of pediatric dentistry.This study put forward mapping of application of various designs of lingual holding arch appliance and to verify themain gap in the research on this field.Methods: This is a scoping review that took place in 2021 following PRISMA-ScR Guideline. Data was searched throughthe database PubMed, SCOPUS, Google scholar The search strategy included keywords’ bilateral fixed space maintainer’‘space maintainer’ ‘lower lingual holding arch’ ‘fixed lingual arch appliance’ ‘functional lingual arch holding appliance’A total of eleven studies from nine hundred and thirty original articles were identified and were included and reviewed.The study selection and tabulation of data were performed by two independent reviewers. Any disagreement in studyselection was resolved by a third reviewer.Conclusion: In the transitional phase, preventive and interceptive orthodontic plays a significant role in minimizing theinevitable developing malocclusion The mapping determined all proposed designs for the prevention of space loss. Eachdesign needs to be carefully selected based on the phase of mixed dentition. This paper provides information on variousdesigns of a lingual arch space maintainer, and it can be concluded that there is a necessity for long-term follow-up studiesfor further research in the field.

Dental Arch Changes with Two Different Trans-Palatal Arch

Background: Rapid maxillary expansion (RME) is a dentofacial orthopedic treatment often used to treat patients with narrow palate and transverse maxillary growth deficiency. Introduction: This treatment leads to correction of posterior dental crossbites, coordination of the upper and lower arches and gaining arch perimeter in patients with tooth size/arch size discrepancies. To stabilize the results obtained with RME and to limit or avoid the relapse, the use of Transpalatal Arch (TPA) would be recommended. Objectives: The aim of this study is to evaluate short-term maxillary changes in patients treated with RME followed by TPA with and without palatal arms. Materials and Methods: 30 patients, 16 females and 14 males (mean age of 9.7 yrs ranging between 9 and 12), were treated by expansion with palatal Hyrax-type expander. After this period, it was removed and one of the two different types of TPA was used. The two different TPA were a 0.036-inch stainless steel wire with a loop directed mesially in the middle, one maintained the original design (TPA), the second one presented arms extended to canines (TPAa). Dental casts were collected for each patient for each treatment step; before (T0), after expansion (T1) and after TPA or TPAa (T2). To assess differences in dental arches after the two treatment phases, three-dimensional (3D) dental casts were used to make more predictable measurements compared with caliper measurements that presented intra-examiner and inter-examiner measurements errors. Results: In TPAa group, differences between the value at the end of the retention period and at the end of expansion showed no statistical significance. Instead in TPA group, the same measurements suggested a reduction of value in almost all dental transverse diameters. Statistically significant differences in dental measurements were found between TPAa and TPA. Conclusion: Results confirm the hypothesis that TPAa can allow to better maintain dental transverse dimensions.

Orthodontic Management of Severe Dentoalveolar Collapse with Miniscrew-Assisted TMA Cantilever Springs and Bite Blocks

Introduction: Management of mutilated cases is challenging, and adult patients often require orthodontic correction of occlusion before prosthetic replacement of missing teeth. Objective: To highlight the novel, simple, hygienic, and efficient miniscrew-supported Beta titanium molybdenum alloy (TMA) cantilever spring for uprighting severe mesially tipped molars for interdisciplinary treatment. Diagnosis and Treatment: A 23-year-old male patient presented with skeletal Class I relation, average growth pattern, Class II Division 1 malocclusion with dentoalveolar collapse, crowding, multiple missing, supraerupted teeth, and severe mesially tipped mandibular third molars. MBT appliance with 0.022˝ slot was used to achieve the objectives. 38 and 48 were uprighted and protracted with miniscrew implant-supported TMA cantilever springs to substitute 37 and 47. Mild intrusion of maxillary posterior teeth was done with acrylic bite blocks and transpalatal arch (TPA), followed by prosthetic replacement of missing teeth. Results: The patient had a consonant smile arc and a pleasing soft tissue profile. 38 and 48 were uprighted and protracted with good vertical control, and the mesial pockets were eliminated. 17 and 27 were intruded, and group function occlusion was established. Class I canine relationship, normal overjet, and overbite were achieved. Conclusion: Miniscrew supported TMA cantilevers are efficient for uprighting of severely tipped 38 and 48 without extrusion, unlike the conventional mechanics. 18, 28, 38 and 48 with good root forms can be protracted and substituted as 17, 27, 37 and 47 respectively to minimize or eliminate prosthetic rehabilitation.

A non-invasive system to manage impacted teeth associated with a large dentigerous cyst.

A male patient aged 11 years presented a large dentigerous cyst in the lower left quadrant associated with retained deciduous lower lateral incisor and canine and impacted, unerupted corresponding permanent ones. The treatment consisted in marsupialisation and placement of a modified lingual arch that held a tube for decompression used for irrigation of the cystic cavity in a comfortable way for the patient and for the clinician.The same lingual arch was later used as an anchorage method for traction of the retained teeth. The final records showed complete resolution of the cyst and retained teeth were successfully Aligned into the oral cavity.

Correction of a prominent premaxilla in a juvenile with a bilateral cleft lip and palate using a novel, hybrid function regulator, the FR-BCPPm, followed by preadjusted fixed appliances: A 20-year follow-up.

A seven-year-old boy with a repaired bilateral cleft lip and palate, presented with a severe skeletal II base and an extremely prominent premaxilla. He had grossly incompetent lips with lower lip trapping, an 18.5-mm overjet, a deep overbite, markedly retroclined lower incisors, bilateral crossbites and 12-mm-wide alveolar gaps together with 6-mm vertical steps between the extruded premaxillary incisors and the posterior teeth. Before the eruption of the permanent canines, there was an urgency to approximate the opposing cleft alveolar margins and to level the split maxillary occlusal plane, in order to facilitate the successful insertion and subsequent consolidation of secondary alveolar bone grafts.A new functional appliance was therefore designed to achieve this objective, which drew components from Fränkel's FR I and FR III function regulators. Together with a couple of novel components, it created a hybrid appliance, namely the function regulator for juveniles with a bilateral cleft and a prominent premaxilla: the FR-BCPPm.The patient was treated with this appliance and a nocturnal headgear at 7-13 years, together with a concomitant quad helix appliance followed by a transpalatal arch and bilateral bone grafts. He was then treated non-extraction up to the age of 17 years with preadjusted fixed appliances to correct his residual, crowded Class II malocclusion.The marked improvement in his occlusion, dentofacial appearance and his perioral function after a decade of treatment was then followed up over 20 years, during which time mild relapse of the incisor overjet and moderate recurrence of the lower anterior misalignment was noted two years after treatment.While no further relapse was observed at the four-year post-treatment review, by 20 years after treatment, a little further misalignment of the lower anterior teeth was noted, half of which was deemed to be attributable to age-related maturation.

Evaluation of the Effects of Mandibular Lingual Arch on Dentoalveolar Structures in Orthopedic Face Mask with Rapid Palatal Expansion Treatment of Class III Malocclusions

Evaluation of the Effects of Mandibular Lingual Arch on Dentoalveolar Structures in Orthopedic Face Mask with Rapid Palatal Expansion Treatment of Class III Malocclusions

Does Early Treatment Improve Clinical Outcome of Class II Patients? A Retrospective Study.

The present study was carried out to evaluate the benefits from one-phase Class II Early Treatment (ET) using extraoral forces and functional appliances but without intermaxillary forces and eventual lower leeway space preservation compared to two-phase Class II Late Treatment (LT) with the need for extractions and full fixed appliances as well as lower incisor proclination. The ET group (n = 239, 115 M, 124 F, mean age 10.6 ± 1.2 years), with first premolars not in contact and the second deciduous lower molars preserved, was compared to the LT group (n = 288, 137 M, 151 F, mean age 12.4 ± 1.5 years). The ET group was first treated with headgears, growth guide appliances, or Teuscher activators and, in borderline crowding cases, with lower space maintenance by a lingual arch, lip bumper, or fixed utility arch. The LT group and the second phase of ET were treated with full fixed appliances including intermaxillary forces such as Class II elastics or noncompliance devices; headgear and a growth guide appliance were also used. Cephalograms and plaster models were taken before (T1) and after treatment (T2) to calculate cephalometric changes and space balance discrepancies. The differences between T1 and T2 were analyzed by a t-test for normally distributed data and by the Mann–Whitney Test for nonnormally distributed data at a level of p < 0.05. The groups were defined as statistically homogeneous at T1. A statistical analysis showed that the ET group (mean treatment time 35.3 ± 13.3 months) was significantly associated with a 22.2% lower extraction rate, 15.9% less need for a full fixed appliance, and more than 5° less incisor proclination in the nonextraction cases compared to the LT group (mean treatment time 25.9 ± 8.1 months); treatment time significantly increased in the ET group compared to the LT group. Early Class II treatment resulted in a significant treatment effort reduction in more than one third of the patients and less lower incisor proclination, even if it clinically increased treatment time.