European journal of orthodontics最新文献

Background: Clear aligners represent a modern alternative to traditional fixed orthodontic appliances, offering aesthetic and removable treatment options. However, variability in clinical outcomes and treatment protocols has led to inconsistent evidence regarding their effectiveness and stability.

Objectives: To systematically review and synthesize available evidence from randomized and non-randomized trials comparing the quality and stability of orthodontic treatment outcomes using clear aligners versus fixed appliances.

Search methods: A comprehensive literature search was conducted across seven databases (PubMed®, Google™ Scholar, Embase®, Scopus®, Web of ScienceTM, the Cochrane Central Register of Controlled Trials, ProQuest) up to February 2025, identifying relevant clinical trials assessing treatment outcomes with clear aligners and fixed appliances.

Selection criteria: Randomized controlled trials and non-randomized clinical trials comparing orthodontic treatment outcomes of clear aligners versus conventional fixed appliances in patients undergoing orthodontic treatment were included.

Data collection and analysis: Two reviewers independently screened titles, abstracts, and full texts, extracted data, and assessed the risk of bias for each included study. The Cochrane Risk of Bias tool (RoB2 tool) was used for randomized controlled trials, while the ROBINS-I tool was applied for non-randomized studies. When appropriate, random-effects meta-analyses were performed. The certainty of the evidence for each outcome was evaluated using the GRADE approach.

Results: Fifteen trials involving 1084 patients were included. The risk of bias varied across studies. No significant differences were found in treatment quality or duration between clear aligners and fixed appliances in non-extraction cases, although sensitivity analyses suggested shorter treatment duration with clear aligners. In extraction cases, fixed appliances provided superior treatment quality, attributed to enhanced control of tooth movements. Limited evidence indicated similar post-treatment stability between the two interventions. However, study heterogeneity and short follow-up durations limited the strength of conclusions.

Conclusions: Both clear aligners and fixed appliances effectively achieve orthodontic treatment goals. Case complexity and patient compliance should guide appliance selection. Further large-scale, well-designed trials with long-term follow-up are necessary to define comparative outcomes.

Registration: The protocol for this review was registered with PROSPERO (CRD420251072157) during its initial stages.

Background: Utilizing 3D facial scans with the aid of digital modeling tools and additive manufacturing is a promising technique for customization of facemask (FM) appliance for correction of Class III malocclusion.

Objectives: To evaluate the efficacy of a modified 3D-printed maxillary protraction FM compared with a commercially available adjustable FM for the correction of Class III malocclusion due to maxillary retrognathism.

Methods: This prospective randomized controlled clinical trial enrolled a total of 34 patients aged 7-12 years with skeletal Class III malocclusion requiring maxillary protraction therapy, and were randomly allocated into two groups with a 1:1 ratio. Group 1 was allocated a 3D customized protraction facemask (3DFM), while Group 2 was allocated to a commercially available conventional Petit-type facemask (CFM). The 3DFM was individually designed using a 3D scan of the face obtained using a Revopoint scanner (Revopoint 3D Technologies Inc., China). The FM was modeled using SolidWorks software and manufactured from Acrylonitrile Butadiene Styrene polymer using a Creality K1 Max 3D printer (Creality 3D Technology Co., Ltd., Shenzhen, China). Lateral cephalograms were taken at pretreatment (T1) and post-treatment (T2) after 9 months for analysis.

Results: Both groups showed significant forward movement of point A (A point to SN perp, P < .000 for both groups) over the period of evaluation, with no significant differences between groups (mean difference (MD) = 0.32 mm, 95% CI: -0.11 to 0.43, P = .240). Both groups showed a significant posterior displacement of SNB (P < .000), with no significant difference between groups (MD = 0.14°, 95% CI: -0.46 to 0.71, P = .671). The ANB angle significantly improved in both groups (P < .000) with no statistically significant differences (MD = 0.21°, 95% CI: -0.51 to 0.96, P = .542). The 3DFM group reported less soft tissue irritation compared with the CFM group. Sleep disturbances were significantly more common in the CFM group compared with the 3DFM group (P = .032, 95% CI: 0.028 to 0.625).

Conclusions: Both 3DFM and CFM produced significant advancement of the maxilla, as demonstrated by increases in SN-nasion perpendicular and SNA angle. Slightly greater maxillary protraction in the 3DFM group suggests a potential biomechanical advantage although this is unlikely to be clinically significant over the long-term.

Registration: ClinicalTrials.gov on 12 April 2021 (registration number: NCT06250127).

Background: This randomized controlled trial aimed to evaluate the skeletal and dentoalveolar changes resulting from the functional treatment with mini-implant supported Twin Block (MITB) appliance compared to the conventional Twin Block (TB) appliance in treating skeletal Class II Division 1 malocclusion.

Methods: A two-arm, parallel-group RCT was conducted at X University from March to September 2021. Forty-four patients with Class II Division 1 malocclusion (ANB 5°-9°, SNB 72°-77°, overjet 5-8 mm) were randomized to receive either MITB (n = 22, experimental group) or TB (n = 22, control group). Randomization was computer-generated, and outcome assessors were blinded. Skeletal and dentoalveolar changes were assessed using lateral cephalometric radiographs before treatment (T0) and at the end of the active treatment phase (T1). Data were analyzed using the Mann-Whitney U test, paired t-test, and independent t-test.

Results: Of the 44 participants randomized, 41 completed the study (23 males, 18 females; mean age 12.05 ± 1.02 years). Both groups showed reduction in maxillary position (SNA) with no significant differences between or within groups. Mandibular advancement (SNB) and skeletal relationship (ANB) improved significantly in both groups, with greater changes in the MITB group (SNB: 3.35° vs. 2.17°, P = 0.004; ANB: -3.76° vs. -2.41°, P = 0.003; Cohen's d = 0.91 vs. Cohen's d = 0.97). The MITB group also showed significantly greater increases in mandibular corpus length (3.47 mm vs. 2.23 mm; P = 0.016; Cohen's d = 0.83), total mandibular length (4.48 mm vs. 3.26 mm; P = 0.049; Cohen's d = 0.66), and mandibular base position (4.01 mm vs. 2.7 mm; P = 0.004; Cohen's d = 0.95). Skeletal discrepancy decreased more in the MITB group (3.71 mm vs. 2.29 mm; P = 0.005; Cohen's d = 0.93). The MITB group also exhibited less lower incisor protrusion (0.73° vs. 3.81°; P < 0.001; Cohen's d = 2.62) and mesial positioning of the mandibular molar (0.13 mm vs. 1.33 mm P < 0.001; Cohen's d = 1.81). Pancherz's analysis revealed 74% skeletal correction of overjet and 82% skeletal correction of molar relationship in the MITB group.

Harms: Four orthodontic mini-implants out of 42 (9.5%) failed in two patients.

Conclusions: The mini-implant supported Twin-Block appliance produced greater skeletal correction and reduced dentoalveolar side effects compared to the conventional Twin Block. These results support the use of mini-implants supported Twin Block as a treatment option for Class II Division 1 malocclusion.

Trial registration: ClinicalTrials.gov, Clinical Trials ID: NCT06403033.

Background: P-values convey statistical significance while effect estimates and confidence intervals (CIs) place emphasis on the clinical significance. The aim of this study was to determine the frequency of reporting clinical or statistical significance in European Orthodontic Society (EOS) Congress scientific poster abstracts and to ascertain whether the conclusions drawn are based on either clinical or statistical significance.

Materials and methods: Abstracts published between 2014 and 2024 were included. Pre-piloting and calibration were undertaken prior to data collection. Abstract characteristics were extracted independently by two reviewers. Descriptive statistics and frequency distributions were calculated.

Results: A total of 3654 abstracts were analysed. The highest number of abstracts were presented in 2018 (13.0%). Epidemiological studies (cross-sectional, case-control, cohort, survey) (54.7%) were frequently presented, followed by laboratorial studies (17.4%) and systematic reviews (7.7%). No inferential statistics were commonly reported (58.5%). Within the abstracts reporting statistical significance (41.1%), typically only P-values were reported (32.5%), followed by the term 'statistically significant' stated only (3.7%), P-values in conjunction with estimates and 95% CIs (1.7%), P-values and 95% CIs (1.4%), 95% CIs (0.8%), estimates and 95% CIs (0.6%), and P-values and estimates (0.4%). When interpreting the reported results in the conclusion section, these were typically based on P-values (31.2%) or the term 'statistically significant' stated only, without consideration of outcomes between groups (14.7%). 95% CIs (0.7%), P-values and 95% CIs (1.3%), P-values in conjunction with estimates and 95% CIs (1.6%) and estimates and 95% CIs (0.5%) were infrequently considered. Across the study timeframe (per year), the results and author conclusions tended to be based on P-values primarily.

Limitations: Only one society congress was assessed which may impact the generalizability of the results.

Conclusions: Clinical significance is often under-reported in abstracts presented at EOS. Where applicable the reporting of clinical significance (effect size with CIs) and their interpretation in poster abstracts should be stipulated as this allows clinicians to gauge both the size and range of the observed differences between groups and the relevance to their clinical practice.

Introduction: This study aimed to investigate whether orthodontic treatment with fixed appliances increased concentration of various monomers in patients' saliva.

Methods: The study included 30 patients aged 10-18. Saliva samples were collected at three time points: before the start of active treatment, immediately after the bonding of orthodontic brackets and during the first follow-up visit between 4 and 6 weeks after bonding. Gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) were employed to analyse the samples.

Results: Measurable levels of poly-EGDMA, HEMA, and BMAEPH were detected in saliva samples collected immediately after bracket bonding. Concentrations varied among patients. However, these substances were not quantifiable in saliva 4-6 weeks after bracket placement.

Conclusions: The bonding of orthodontic brackets is associated with a transient increase in the concentration of bonding material constituents in saliva immediately after placement. The findings suggest that, using the current analytical methods, this release is temporary.

Introduction: The center of resistance (CRES) is regarded as the fundamental reference point for predictable tooth movement. Only a handful of studies have evaluated the CRES of a maxillary canine; however, most had a low sample size, used idealized models, or involved 2D analysis. The objectives of this study were to determine the 3D location of the CRES of maxillary canines, evaluate its variability, and investigate the effects of applying orthodontic load from two directions on the location of the CRES.

Methods: Cone-beam computed tomography (CBCT) scans of 50 maxillary molars from 25 patients (mean age, 20.8 ± 8.7 years) were used. CBCT images were manipulated to extract 3D biological structures via segmentation. The segmented structures were cleaned and converted into virtual mesh models made of tetrahedral triangles having a maximum edge length of 1 mm. The block, which included the canines and periodontal ligament, consisted of a mean of 4863 ± 1544 nodes and 23 501 ± 8512 tetrahedral elements. Specialized software was used to preprocess the models to create an assembly and assign material properties, interaction conditions, boundary conditions, and load applications. Specific loads were applied, and custom-designed algorithms were used to analyze the stress and strain to locate the CRES. The CRES was measured in relation to the geometric center (R point) of the buccal surface of the canine.

Results: The average location of the CRES for the maxillary canine was 3.91 ± 1.33 mm palatal, 6.52 ± 1.24 mm distal, and 8.37 ± 2.39 mm gingival relative to R. None of the canines showed a convergence of the CRES at a single point, but the difference was not significant (P > .01). In the anteroposterior and the vertical planes, the CRES showed significant association with root divergence (P < .01).

Conclusion: The canine CRES was found distal, apical, and palatal to the R point. It was located at 61.5% of the total tooth length or 17.2 mm measured from the cusp tip. Anatomic variation and orientation have a significant impact on the 3D localization of the CRES.

Objectives: Maxillary transverse discrepancies are routinely addressed by palatal expansion. Nasal septum deviation is suspected to be related to these discrepancies. Current evidence using linear and angular measurements from two-dimensional radiographs on the effect of rapid palatal expansion on the nasal septum is not conclusive. The objective of this study was to apply three-dimensional geometric morphometric analyses to cone-beam computed tomography scans of the nasal septum to investigate changes in response to palatal expansion.

Methods: Cone-beam computed tomography scans of the nasal septa of 71 subjects (53, expansion and 18, control) from 2 timepoints were segmented on using Mimics™ software. Anatomical landmarks and semilandmarks were digitized using Checkpoint™. Differences in septal deviation between the two timepoints were tested. Generalized Procrustes analysis and principal component analysis assessed overall shape differences and pattern variance in the septum. Least square regression was used to test for correlations. Heat maps visualized which areas exhibited the greatest amount of change.

Results: In the control group, none of the septum deviation variables changed significantly between the timepoints, while all were significantly different for the expansion group. Heatmaps showed greater increase in interlandmark distances for the expansion group compared with the controls, with the posterosuperior part of the septum bearing the greatest change and the central, inferior part showing the least change.

Conclusion: Findings suggest that the septum does not straighten during expansion but continues to deviate with age.

Introduction: This study aimed to identify key genes associated with osteoclast activity during orthodontic tooth movement (OTM) using bulk RNA sequencing and experimental validation.

Methods: An OTM model was established in mice by placing a nickel-titanium closed-coil spring between the maxillary first molar and incisors. Female C57BL/6 mice were assigned to Day 7, Day 14, and Control groups. Alveolar bone changes were assessed by micro-computed tomography (micro-CT) and hematoxylin and eosin (HE) staining. Osteoclasts were quantified by tartrate-resistant acid phosphatase (TRAP) staining. Total RNA from alveolar bone was analyzed by bulk RNA sequencing. Selected genes were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Immune cell quantification was performed by ImmuCellAI. Immune cell infiltration, and related gene expressions were evaluated by immunohistochemistry and immunofluorescence.

Results: A total of 227 and 152 upregulated differently expressed genes (DEGs) were identified on Day 7 and Day 14, respectively, many of which were related to immune response and osteoclastogenesis. Ten hub genes, including Il1b, Il6, Ccl3, Ccl2, Cxcl2, Mmp9, Timp1, Mmp3, Ccrl and Sele, were positively correlated with osteoclast-related genes (Lilr4b, Socs3, Ctsk, Fos, Il1b, Itgb3, Ccl3, Nmb, Ccr1, Spi1). Macrophage infiltration increased during OTM, and CCL3, CCL2, CXCL2, and CCR1 were colocalized with macrophages.

Conclusion: Our study highlights key immune genes and immune cell involvement in OTM. These findings may provide molecular and cellular targets for modulating osteoclast activity and orthodontic tooth movement.