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Dentistry Medical European Journal of Orthodontics - current issue
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Background</div>Periodontal ligament cells (PDLCs) possess mechanotransduction capability, vital in orthodontic tooth movement (OTM) and maintaining periodontal homeostasis. The study aims to elucidate the expression profiles of mechanosensitive ion channel (MIC) families in PDLCs and how the inflammatory mediator alters their expression and function, advancing the understanding of the biological process of OTM.<div class="boxTitle">Methods and methods</div>Human PDLCs were cultured and exposed to TNF-α. RNA sequencing was conducted to explore the mRNA transcriptome of both normal and TNF-α-treated PDLCs. Differentially expressed MICs were identified and analyzed. The functional expressions of TRPA1 and TRPM8 were further validated by RT-qPCR, Western blot, and calcium influx assays.<div class="boxTitle">Results</div>All 10 identified MIC families or subfamilies were expressed in PDLCs, with the TRP family being the most abundant. KCNK2, PIEZO1, TMEM87A, and PKD2 were the most expressed ion channels in PDLCs. TNF-α altered the expression of the MIC families, resulting in increased expression of PIEZO, K2P, TRP, TMEM63, and TMEM87 families and decreased expression of ENaC/ASIC, TMC/TMHS/TMIE, TMEM150, TMEM120, and L/T/N-Type calcium channel families. Furthermore, 17 DEMICs were identified (false discovery rate < 0.05), with the top five (fold change ≥ 2), including upregulated TRPA1 and TRPM8. The functional expressions of TRPA1 and TRPM8 were verified, suggesting that TNF-α significantly increased their expression and sensitized their activities.<div class="boxTitle">Conclusions</div>The study provides comprehensive expression profiles of the MICs in PDLCs and reveals how inflammation alters the expression and activities of the MICs. Treatments targeting these MICs may offer promising strategies for improving OTM and preventing complications in inflammatory environments, ultimately leading to more effective and safer orthodontic practices.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Background/Objectives</div>Evidence suggests nasal airflow resistance reduces after rapid maxillary expansion (RME). However, the medium-term effects of RME on upper airway (UA) airflow characteristics when normal craniofacial development is considered are still unclear. This retrospective cohort study used computer fluid dynamics (CFD) to evaluate the medium-term changes in the UA airflow (pressure and velocity) after RME in two distinct age-based cohorts.<div class="boxTitle">Materials/Methods</div>The study included 48 subjects who underwent RME divided into two cohorts: a 6−9-year-old group (EEG group: early expansion group − 25 subjects) and an 11−14-year-old group (LEG group: late expansion group − 23 subjects). The nasal cavity and pharyngeal anatomy were segmented from Cone-beam computed tomography reconstructions taken before RME (T0) and 12 after RME (T1). The two UA airflow variables (pressure and velocity) were simulated using CFD. The maxillary expansion (PW) amount, two cross-sectional area measurements (CS1 = anterior cross-section and CS2 = posterior cross-section), and four UAs’ subregions (NC = nasal cavity, PAtotal = pharyngeal airway, NP = nasopharynx, VP = velopharynx, and OP = Oropharynx) were also considered. All data were statistically analyzed.<div class="boxTitle">Results</div>At the baseline, the airflow pressure, velocity, and noted obstructions were significantly higher in the EEG compared to LEG. At T1, there was a significant improvement in the median airway parameters in both groups, which was remarkably greater in the EEG. A significant negative correlation was found between pressure/velocity and both CS2 and NP. According to the CFD plots, the airflow pressure and velocity changes could be attributed to the reduction of the adenotonsillar tissues’ sizes, which were remarkably more marked in the EEG.<div class="boxTitle">Limitations</div>The results of this study cannot be generalized since they referred to a retrospective orthodontic sample without obstructive adenotonsillar hypertrophy.<div class="boxTitle">Conclusions/Implications</div>Twelve months after RME, normal craniofacial developmental changes and spontaneous adenotonsillar tissues volume regression could represent the most significant factors influencing UA airflow changes.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Objectives</div>To evaluate whether unilateral functional posterior crossbite in growing children creates an asymmetry in masseter muscle thickness and whether this asymmetry is normalized after crossbite correction.<div class="boxTitle">Materials and methods</div>Two groups of growing individuals were studied prospectively: (i) a treatment group: children with unilateral functional posterior crossbite, undergoing crossbite correction with maxillary expansion; and (ii) a control group: children without transversal malocclusions and orthodontic treatment. The thickness of the masseter muscles was measured bilaterally using ultrasonographic recordings at three time points: pre-treatment (T0); 9 months after (T1); and 30 months after posterior crossbite correction (T2); and at equivalent time points in the control group. Differences within and between the groups were evaluated using paired and unpaired <span style="font-style:italic;">t</span>-tests respectively.<div class="boxTitle">Results</div>It was found that the thickness of the masseter muscles in patients with unilateral functional posterior crossbite was significantly thinner on the crossbite side (<span style="font-style:italic;">P</span> = .013) by 0.5 mm. At T1, the masseter muscle of the treated crossbite side was thicker than that of the previous normal side (0.3 mm difference; <span style="font-style:italic;">P</span> = .046) while this difference disappeared at T2 (<span style="font-style:italic;">P</span> > .05).<div class="boxTitle">Limitations</div>The lack of the inclusion of an untreated posterior crossbite group, and the heterogeneity in appliances used are the principal limitations of this study.<div class="boxTitle">Conclusions</div>The masseter muscles in untreated individuals with unilateral functional posterior crossbite are thinner in the crossbite side than in the contralateral non-crossbite side. This muscular asymmetry however is eliminated some time after successful treatment of this malocclusion, possibly due to the bilateral symmetrization of the activity of the elevator masticatory muscles.</span>
<span class="paragraphSection">This is a correction to: Esraa Salman Jasim, Ammar Salim Kadhum, Poly-ether-ether-ketone versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 2: periodontal health and microbial biofilm assessment, <span style="font-style:italic;">European Journal of Orthodontics</span>, Volume 46, Issue 5, October 2024, cjae048, <a href="https://doi.org/10.1093/ejo/cjae048">https://doi.org/10.1093/ejo/cjae048</a></span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Background</div>The infrazygomatic miniscrew implants (IZC-MSI) serve as innovative temporary anchorage devices placed parallel to the roots of molars in the infrazygomatic crest region, leveraging their extra-radicular location to support the en masse distalization and intrusion of the maxillary dentition. The efficacy and stability of these screws are crucial for their application in contemporary orthodontic practices.<div class="boxTitle">Objectives</div>This systematic review aimed to estimate the success rate and factors affecting the stability of IZC-MSI.<div class="boxTitle">Search methods</div>An electronic search was conducted on 7 February 2024 across the following databases: PubMed, Scopus, EMBASE, and Cochrane databases without any restriction on language and time of publication.<div class="boxTitle">Selection criteria</div>The review included clinical trials (both randomized and non-randomized) and retrospective cohort studies that utilized infrazygomatic miniscrew anchorage for orthodontic tooth movement in human participants.<div class="boxTitle">Data collection and analysis</div>The proportion of success rate was calculated and factors affecting stability (patient and implant-related factors) such as age, sex, implant position, and loading characteristics were subjected to subgroup analysis and meta-regression. The quality assessment of studies was done using the Cochrane risk-of-bias tools for randomized (RoB 2.0) and non-randomized trials (ROBINS-I).<div class="boxTitle">Results</div>Fourteen studies (<span style="font-style:italic;">n</span> = 1683 IZC-MSI) were included in the meta-analysis revealing a 92% success rate of IZC-MSI (C.I. 87%–95%; prediction interval: 66%–99%; <span style="font-style:italic;">I</span><sup>2</sup> = 80%). Studies with sample size > 100 presented a 94% success rate (C.I. 91%–96%; <span style="font-style:italic;">I</span><sup>2</sup> = 63%) and moderate heterogeneity. Meta-regression analysis revealed no significant relation between age and success rate. Significant heterogeneity was observed in the subgroup analysis of host-, implant- and other related risk factors affecting stability and limited correlation was found. The risk-of-bias assessment revealed high risk in five, moderate in five, and low in four studies.<div class="boxTitle">Conclusions</div>IZC-MSI have shown a good success rate for their clinical application. Although some factors appear to influence IZC-MSI stability, the majority of them necessitate additional investigation due to the low quality of evidence. Furthermore, high-quality studies are needed to confirm the results of this meta-analysis and address other important factors such as operator’s experience, insertion torque, and sinus penetration that could not be analysed due to limited data.<div class="boxTitle">Registration</div>CRD42024469048.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Objectives</div>This study aimed to determine the genetic and environmental contributions to phenotypic variations of palatal morphology during development.<div class="boxTitle">Methods</div>Longitudinal three-dimensional digital maxillary dental casts of 228 twin pairs (104 monozygotic and 124 dizygotic) at primary, mixed, and permanent dentition stages were included in this study. Landmarks were placed on the casts along the midpoints of the dento-gingival junction on the palatal side of each tooth and the mid-palatine raphe using MeshLab. Palatal widths, depths, length, area, and volume were measured using those landmarks. Univariate genetic structural equation modelling was performed on twin data at each stage of dental development.<div class="boxTitle">Results</div>Except for anterior depth, all palatal dimensions increased significantly from the primary to permanent dentition stages. The phenotypic variance for most of the palatal dimensions during development was best explained by a model, including additive genetic and non-shared environment variance components. Variance in volume and area in the primary dentition stage was best explained by a model including additive genetic, shared environment, and non-shared environment variance components. For posterior palatal depth and width, narrow-sense heritability estimates were above 0.8 for all dental developmental stages. In contrast, heritability estimates for other palatal traits fluctuated during development.<div class="boxTitle">Limitation</div>This study was limited to twins of European ancestry.<div class="boxTitle">Conclusions</div>Additive genetic and non-shared environmental factors primarily influenced palatal morphology during development. While the genetic influence on different aspects of the palate varied throughout development, it was particularly strong in the posterior region of the palate and during the permanent dentition stage.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Objectives</div>The purpose of this retrospective study was to compare the dento-skeletal changes observed in growing Class III patients treated with the Face Mask Protocol (FMP) with and without Bite Block (BB).<div class="boxTitle">Materials</div>Thirty subjects (12 f, 18 m) who underwent FM/BB therapy were compared to a matched group (FM) of 29 patients (15 f, 14 m) treated without BB. All patients were evaluated before treatment (T0), at the end of active treatment (T1), and at a post-pubertal follow-up observation (T2). A control group (CG) of 20 subjects (10 f, 10 m) with untreated Class III disharmony was used for the comparison of post-pubertal changes. Intergroup statistical comparisons were performed with the independent samples <span style="font-style:italic;">t</span>-test (<span style="font-style:italic;">P</span> < .05).<div class="boxTitle">Results</div>The comparison between treated samples showed a significant improvement of SN^GoGn (FM/BB vs FM, −2.1°), Overbite (FM/BB vs FM, +1.2 mm), and vertical position of lower molars FM/BB vs FM, −3 mm). When compared with the controls, both treated groups revealed a significant improvement of SNA (FM/BB, +1.8°; FM +2.1°), ANB (FM/BB +1.6°, FM +2.4°), gonial angle (FM/BB −4.9°; FM −4°), incisor inclination (Upper, FM/BB +1.7°, FM +2.3°; Lower, FM/BB −2.5°, FM −2.7°), and Overjet (FM/BB +3.2 mm; FM +4 mm). Improvement of SN^GoGn (−2.1°), Overbite (+1.8 mm), and vertical position of lower molars (−3.8 mm) were observed when FM/BB was compared with CG.<div class="boxTitle">Limitations</div>Limitations are related to the difficulty to recruit a larger contemporary long-term control group due to ethical reasons.<div class="boxTitle">Conclusion</div>Both FM protocols induced favorable changes in the treatment of Class III malocclusion with a good post-pubertal stability. The BB allows a more efficient control of the vertical skeletal relationship.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Background</div>The fear of pain during the various stages of orthodontic treatment with fixed appliances is a common concern of patients. Therefore, the present research aimed to thoroughly investigate the impact of bracket architecture on pain perception during active treatment, debonding, and adhesive removal.<div class="boxTitle">Materials</div>One hundred consecutive patients who completed treatment with one of two bracket systems (2-slot brackets with an integral base or conventional twin brackets with foil mesh) were included in this prospective cohort study. Participants were asked to evaluate the level of pain encountered throughout their orthodontic treatment with the fixed appliances and during bracket and adhesive removal, utilizing a 0–10 numerical rating scale. Two different methods of bracket removal (bracket debonding pliers and Lift-Off Debonding Instrument) and adhesive removal (adhesive removal pliers and rotary instrument) were tested.<div class="boxTitle">Results</div>Our study found moderate and comparable levels of pain during active treatment in both groups (4.4 ± 1.6 in the 2-slot group and 3.9 ± 1.9 in the Twin group). Debonding of brackets with integral base caused more discomfort compared to conventional twin brackets and using bracket removal pliers elicited more pain sensations than when Lift-Off Debonding Instrument were employed. Patients are likely to prefer adhesive removal methods involving rotary instruments despite the sound and vibrations produced by contra-angle handpiece.<div class="boxTitle">Limitations</div>The lack of randomization in patient grouping introduces an increased risk of bias.<div class="boxTitle">Conclusions</div>The results of the present study suggest that the bracket architecture, particularly the construction of the bracket base, affects the level of discomfort experienced during debonding.<div class="boxTitle">Trial registration</div>ClinicalTrials.gov, NCT06324162, Registered 20 March 2024—Retrospectively registered, <a href="https://clinicaltrials.gov/study/NCT06324162">https://clinicaltrials.gov/study/NCT06324162</a></span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Objectives</div>To develop a reproducible, reliable clinical index of alveolar bone grafting (ABG) outcome based on the eruption position of the cleft canine tooth and determine the association between eruption position and radiographic outcome at 6 months post-grafting.<div class="boxTitle">Methods</div>Children with complete, non-syndromic, unilateral/bilateral cleft lip and palate in the West of Scotland were identified. Post-ABG radiographic outcome (Kindelan index) and canine eruption position in children with a cleft of the alveolus who had undergone ABG were documented. A Kindelan score was assigned to the 6-month post-bone-graft radiograph. Following canine tooth eruption, four-point clinical index scale (CIS) scores were assigned to maxillary occlusal images taken prior to commencement of definitive orthodontics; 1—canine eruption in alveolar crest, 2—canine eruption buccal to alveolar crest, 3—canine eruption palatal to alveolar crest, and 4—canine impaction. Intra and inter-rater reliability was assessed using Cohen and Fleiss kappa’s, respectively. Duration of orthodontics treatment, number of orthodontic clinic visits, and clinical management of the cleft site space were noted.<div class="boxTitle">Results</div>Eighty-three patients representing 98 bone graft sites were identified. CIS scoring intra- and inter-rater reliability was 0.69–0.99 and 0.63–0.75, respectively. CIS score was associated with reduced visits (<span style="font-style:italic;">P</span> = .015), months in orthodontics (<span style="font-style:italic;">P</span> = .009), and likelihood of space closure (<span style="font-style:italic;">P</span> = .006).<div class="boxTitle">Limitations</div>This is a retrospective study with small numbers but is comparative to other similar studies in the literature.<div class="boxTitle">Conclusions</div>The CIS presented appears to be a reliable index of ABG outcome. It also demonstrates an association with the burden of orthodontic care post-cleft alveolar bone graft.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Introduction</div>Palatal rugae are used as anatomical landmarks on the hard palate, in various clinical applications; in forensics, for insertion of mini-screws, and for superimposition. There is ambiguous evidence on whether they change during orthodontic treatment and to what extent. Therefore, we investigated changes in the shape, complexity, and area occupied by palatal rugae following orthodontic treatment with and without extractions.<div class="boxTitle">Materials and methods</div>Pre- and post-treatment plaster models of maxillae of 28 cases involving first premolar extractions (17 females and 11 males) and 33 non-extraction cases (19 females and 14 males) were scanned and analysed. All participants were selected from a parent sample via discriminant analysis and represent borderline cases. We applied mesh cropping, ball pivoting, distance mapping, contour cropping of rugae, best-fit superimposition, fractal dimension (FD) analysis, and creation of rugae’s convex hull area with Viewbox 4 software. The average distance between the closest points of the outlines of pre- and post-treatment palatal rugae (indicating shape change in the set of rugae), disparity in their pre- and post-treatment FDs (reflecting the complexity of their shapes), area occupied by rugae, arch depth, and size of palatal surface were then computed.<div class="boxTitle">Results</div>The medians of the average distance between pre- and post-treatment outlines after best-fit superimposition were 0.39 mm (interquartile range [IQR]: 0.34–0.51) and 0.27 mm (IQR: 0.22–0.34) mm for the extraction and non-extraction groups, respectively (<span style="font-style:italic;">P</span> < 0.001). The median pre-treatment FDs were 1.497 (IQR: 1.481–1.521) for the extraction group and 1.481 (IQR: 1.456–1.509) for the non-extraction group, whereas their median post-treatment FDs were 1.502 (IQR: 1.472–1.532) and 1.489 (IQR: 1.469–1.501), respectively. The differences between pre- and post-treatment fractal dimensions were not found to be significant, neither within each group, nor across the groups. On the other hand, the surface area occupied by rugae showed a median increase of 14.7 mm<sup>2</sup> (IQR: 0.0–46.5) (<span style="font-style:italic;">P</span> = 0.003) following non-extraction treatment only.<div class="boxTitle">Conclusion</div>Palatal rugae change shape during orthodontic treatment, but their shape complexity, as measured by fractal dimensions, remains unaltered. Extraction treatment exerts a more pronounced effect in shape change compared to treatment without extractions. Nevertheless, non-extraction orthodontic treatment increases the surface on which rugae lie, as measured by means of the convex hull. Although the alterations may appear minor, it is necessary to exercise caution and prudence when employing rugae for superimposition and forensic dentistry purposes.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Objective</div>This retrospective study aimed to compare the three-dimensional (3D) outcomes of the novel miniscrew-anchored maxillary protraction (MAMP) therapy and the bone-anchored maxillary protraction (BAMP) therapy.<div class="boxTitle">Methods</div>The sample comprised growing patients with skeletal Class III malocclusion treated with two skeletal anchored maxillary protraction protocols. The MAMP group comprised 22 patients (9 female, 13 male; 10.9 ± 0.9 years of age at baseline) treated with Class III elastics anchored on a hybrid hyrax expander in the maxilla and two mandibular miniscrews distally to the permanent canines. The BAMP group comprised 24 patients (14 female, 10 male; 11.6 ± 1.1 years of age at baseline) treated with Class III elastic anchored in two titanium miniplates in the infra-zygomatic crest and two miniplates in the mesial of the mandibular permanent canines. Three-dimensional displacements were measured in the pre- and post-treatment cone-beam computed tomography scans superimposed on the cranial base using the Slicer Automated Dental Tools module of 3D Slicer software (<a href="https://www.slicer.org">www.slicer.org</a>). Mean differences (MD) between groups and 95% confidence interval (CI) were obtained for all variables. Intergroup comparison was performed using the Analysis of Covariance (<span style="font-style:italic;">P</span> < .05).<div class="boxTitle">Results</div>Both groups showed improvements after treatment. The MAMP group showed a smaller anterior (MD: −1.09 mm; 95% CI, −2.07 to −0.56) and 3D (MD: −1.27 mm; 95% CI, −2.16 to −0.74) displacements of the maxilla after treatment when compared with BAMP. Both groups showed negligible and similar anteroposterior changes in the mandible (MD: 0.33 mm; 95% CI, −2.15 to 1.34). A greater increase in the nasal cavity width (MD of 2.36; 95% CI, 1.97–3.05) was observed in the MAMP group when compared with BAMP.<div class="boxTitle">Limitations</div>The absence of an untreated control group to assess the possible growth impact in these findings is a limitation of this study.<div class="boxTitle">Conclusion</div>Both BAMP and MAMP therapies showed adequate 3D outcomes after treatment. However, BAMP therapy produced a greater maxillary advancement with treatment, while MAMP therapy showed greater transversal increases in the nasal cavity.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Background</div>Maxillary lateral incisor agenesis is often managed with orthodontic space closure and canine substitution. Anatomic gingival margin heights associated with the maxillary anterior teeth are considered important for achieving aesthetic excellence with space closure, but evidence relating to the perceptions of lay people is poor.<div class="boxTitle">Objectives</div>This study investigated the influence of gingival margin height variation in the maxillary anterior teeth following orthodontic space closure and canine substitution in the absence of maxillary lateral incisor teeth on perceived aesthetics judged by a lay population.<div class="boxTitle">Material and Methods</div>Images of a case treated with space closure and bilateral canine substitution were digitally modified to create gingival margin height variation for the substituted lateral incisors and canines. Six variations were created, including one conforming to accepted norms for anatomic gingival margin heights. Lay people represented by parents of orthodontic patients ranked the images based on aesthetics, with data analysed statistically using linear models at 5%.<div class="boxTitle">Results</div>One hundred and twenty responders were included (median age 48.0 years), 50% male and 81.7% Caucasian, with 87% able to provide specific preferences. In absolute terms, the highest-ranking [image C] had substituted lateral incisor gingival margins below the central incisors (considered normal) but substituted canine margins symmetrically below the substituted lateral incisors (considered to be too low); followed by [image D] with symmetrically level gingival margins; and [image F] with asymmetric substituted lateral incisor margins and substituted canine margins symmetrically too low. The lowest-ranked [image E] had normal substituted lateral incisor margins but asymmetric substituted canine margins. Image C was most often ranked first (29.8% of responders) and image E last (22.1%). After adjusting for potential confounding effects, image E received the worse scores.<div class="boxTitle">Conclusions</div>Anatomic norms for gingival margin height in absent maxillary lateral incisor-canine substitution do not correlate with the highest-ranking aesthetic choices of a lay population. Lateral incisor gingival margins symmetrically below the central incisors and substituted canine margins symmetrically below these ranked highest. Vertical asymmetry in the substituted canine position was considered the least aesthetic.</span>
<span class="paragraphSection"><div class="boxTitle">Abstract</div><div class="boxTitle">Objectives</div>This study aimed to quantitatively investigate the intractable ‘roller coaster effect’ (RCE) that occurs in premolar extraction cases treated with clear aligner therapy (CAT) or straight-wire appliance (SWA).<div class="boxTitle">Methods</div>Protrusion cases treated with extraction of bilateral first premolars were included. Pre- and post-treatment cephalograms were obtained to measure the bending angle of occlusal plane (BAOP), namely the occlusal intersection angle between the anterior occlusal plane (AOP) and posterior occlusal plane (POP). BAOP is proposed as the indicator for quantifying RCE in this study.<div class="boxTitle">Results</div>In the maxillary dentition, BAOP significantly decreased from 177.50 ± 5.57° to 171.10 ± 3.32° in the SWA group (<span style="font-style:italic;">n</span> = 30), and from 178.00 ± 4.66° to 168.10 ± 5.63° in the CAT group (<span style="font-style:italic;">n</span> = 36). In the mandibular dentition, BAOP had no significant change (from 164.90 ± 5.00° to 164.30 ± 6.40°) in the SWA group (<span style="font-style:italic;">n</span> = 29), while significantly decreased from 163.40 ± 6.36° to 155.90 ± 7.48° in the CAT group (<span style="font-style:italic;">n</span> = 37). In the both dentitions, the post-treatment BAOP was significantly smaller in the CAT compared to SWA group. Decrease of BAOP in the CAT group resulted from bending of the AOP rather than POP. Multiple linear regression analysis revealed that the mandibular canine crown length had a positive correlation with the mandibular post-treatment BAOP.<div class="boxTitle">Limitations</div>Only two-dimensional cephalometric measurements were conducted.<div class="boxTitle">Conclusions</div>In premolar extraction cases, CAT undergoes more severe RCE at completion of its first-phase treatment compared to SWA at the end of treatment. Longer mandibular canine crown may mitigate mandibular RCE in CAT.</span>
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