Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

Purpose: White spot lesions (WSLs) can result from bacterial plaque around orthodontic brackets, leading to enamel demineralization. While other preventive strategies rely on patient compliance, incorporating zinc oxide (ZnO) nanoparticles into adhesives offers antimicrobial protection, independent of compliance. This study aimed to develop a ZnO-containing adhesive and evaluated its antibacterial and mechanical properties for clinical application.

Methods: This in vitro study, conducted at Shahid Beheshti University of Medical Sciences, sampled 30 extracted premolar teeth and randomly assigned them to three groups: (1) control (synthesized adhesive without ZnO), (2) ZnO (1.5% ZnO nanoparticles), and (3) XT (Transbond XT, 3M, St. Paul, MN, USA). The adhesive's antibacterial effect was assessed using Streptococcus mutans biofilm inhibition, while mechanical and physicochemical properties were evaluated by measuring shear bond strength (SBS), adhesive remnant index (ARI), degree of conversion (DC), water sorption, water solubility, and microhardness. Data were analyzed using one-way analysis of variance (ANOVA), Tukey's honestly significant difference (HSD), Kruskal-Wallis test, and Mann-Whitney test using SPSS software (IBM, Armonk, NY, USA). P-values less than 0.05 were considered statistically significant.

Results: Statistically significant differences were found among the three groups with respect to SBS (P = 0.023), microhardness (P < 0.001), antibacterial activity (P < 0.001), water sorption (P = 0.003), and water solubility (P < 0.001). No significant differences were observed in DC or ARI. Post hoc tests showed that ZnO outperformed the control in all properties except SBS and did not differ significantly from XT in tested properties.

Conclusion: Incorporating 1.5% ZnO nanoparticles into the synthesized adhesive enhanced antibacterial properties and inhibited biofilm formation without compromising bond strength, DC, water sorption, water solubility, or microhardness. Given its superior antibacterial efficacy over Transbond XT, the ZnO adhesive shows potential as a viable option for orthodontic bonding.

Background: Early orthodontic treatment has evolved significantly over the past decades, with advances in diagnostic techniques, treatment methodologies, and interdisciplinary approaches. Despite its importance in pediatric dental care, a comprehensive bibliometric evaluation of research trends in this field has been lacking.

Objective: To conduct a systematic bibliometric analysis of the research landscape and developmental trends in early orthodontic intervention for children and adolescents from 2000-2025.

Methods: Literature data were retrieved from Web of Science Core Collection and Scopus databases using comprehensive search strategies targeting early orthodontic treatment research. The final dataset of 906 articles was analyzed using VOSviewer 1.6.20 and CiteSpace 6.1R6 visualization software to examine publication trends, author and institutional collaboration networks, journal distributions, geographical contributions, and keyword co-occurrence patterns.

Results: Research output demonstrated consistent growth from 6 publications in 2000 to 85 in 2023. Lorenzo Franchi emerged as the most productive author (12 publications), while the University of Milan led institutional contributions (28 publications). The American Journal of Orthodontics and Dentofacial Orthopedics was the primary publication venue (88 articles). Italy (161 publications) and the USA (144 publications) were the leading contributors. Keyword analysis revealed "children" as the most frequent term (270 occurrences), followed by "orthodontic treatment" (125 occurrences) and "prevalence" (106 occurrences), with distinct evolution patterns showing a transition from fundamental concepts like "growth" (appearing in 2000) to specialized terms such as "obstructive sleep apnea" (2015) and "quality of life" (2020), while citation burst analysis identified "quality of life" with the strongest recent burst strength (5.92).

Conclusion: Early orthodontic treatment research has evolved from foundational concepts to patient-centered outcomes and technological applications, with increasing interdisciplinary focus and internationalization requiring sustained collaborative efforts to address emerging clinical priorities.

Purpose: Interleukin (IL)-17 expression in the periodontal ligament is associated with orthodontically induced inflammatory root resorption (OIIRR). Seeking a convenient, rapid, and non-invasive IL-17 detection approach could help predict OIIRR. In this study, we assessed the potential of the IL-17 level in gingival crevicular fluid (GCF) to be an indicator of OIIRR.

Methods: To enable tooth movement, 8‑ to 10-week-old male Wistar rats were subjected to 20 g/60 g orthodontic force for up to 14 days. GCF and peripheral blood were collected for the IL-17 enzyme-linked immunosorbent assay (ELISA). Histological changes and the expression of IL-17, receptor activator of nuclear factor κB ligand (RANKL), and osteoprotegerin (OPG) in periodontal tissue were evaluated by hematoxylin-eosin and immunohistochemistry staining, respectively. Osteoclasts were visualized by tartrate-resistant acid phosphatase (TARP) staining.

Results: GCF IL-17 level rapidly rose in the early phase of orthodontic loading, accompanied by bone and tooth root destruction. At the later stage, the GCF IL-17 level gradually decreased, while the inflammatory destruction was reduced and the periodontal tissue began to repair. GCF IL-17 expression generally tended to be coincident with the periodontal tissue reaction: GCF IL-17 was robustly correlated to the RANKL/OPG ratio (r_s = 0.72, p = 0.002) or osteoclast number (r_s = 0.84, p < 0.001). Additionally, the GCF IL-17 level was correlated to serum IL-17 (r_s = 0.61, p = 0.016) or periodontal IL-17 (r_s = 0.84, p < 0.001).

Conclusion: The IL-17 level in GCF during orthodontic treatment is associated with OIIRR and, thus, could be an early indicator for developing OIIRR. The advantages of being a convenient, rapid, and non-invasive GCF IL-17 measurement make it a promising method for early detection of OIIRR.

Objective: Temporary anchorage devices (TADs) have been successfully used in the maxilla. However, in the mandible, lower success rates present a challenge in everyday clinical practice. A new TAD design will be presented that is intended to demonstrate optimization of the coupling structure as well as in the thread area for use in the mandible.

Methods: Three TADs were examined: (A) Aarhus® system (68.99.33 A, Medicon, Tuttlingen, Germany), (B) BENEfit® orthodontic screw (ST-33-54209; PSM Medical, Gunningen, Germany) and (C) a new design with a two-part screw thread. The TADs were inserted into artificial bone blocks after predrilling to test primary stability. To test the fracture stability, the TADs were embedded in Technovit® 4004 (Heraeus Kulzer, Wehrheim, Germany) and torsional loaded at an angle of 90° until fracture. The threshold torque values occurring were recorded digitally. The statistical evaluation was carried out using the Kruskal-Wallis test with a post hoc test according to Bonferroni (p < 0.05).

Results: The following values were measured for the insertion torque: A: 33.7 ± 3.3 Ncm; B: 57.1 ± 8.4 Ncm; C: 34.2 ± 1.4 Ncm. There were significant differences between A-B and B-C. The measured values for the fracture strength were as follows: A: 46.7 ± 3.5 Ncm; B: 64.2 ± 5.1 Ncm; C: 55.4 ± 5.1 Ncm. Significant differences were found between all groups.

Conclusion: The adapted screw design has no negative influence on primary and fracture stability. Whether the design has a positive effect on the success rates in the mandible must be clarified in further clinical studies.

Objective: In vitro evaluation of the morphology of the enamel surface before bonding metal tubes and after debonding using spectral domain optical coherence tomography (SD-OCT) and light microscopy.

Methods: In all, 40 extracted caries-free human molars without defects were selected and cleaned. The tooth surfaces were imaged by light microscopy and SD-OCT prior to the placement of metal tubes (Titanium Orthos; Ormco, Brea, CA, USA). The metal tubes were bonded to the teeth using four adhesive systems: group 1) BrackFix Primer SE with BrackFix adhesive, group 2) BrackFix Primer with BrackFix adhesive (VOCO, Cuxhaven, Germany), group 3) Transbond Plus SE Primer with Transbond XT adhesive, group 4) Transbond XT Primer with Transbond XT adhesive (reference, 3M Deutschland, Neuss, Germany). After tube removal, the bonded areas were imaged by light microscopy and/or OCT and evaluated according to the following four criteria: (1) depth of cohesive enamel defect, (2) enamel cracks, (3) adhesive residue after tube removal, and (4) adhesive residues after polishing.

Results: None of the groups had enamel defects or enamel cracks. Group 1 showed significantly less adhesive residue after tube removal than the other groups (p_i ≤ 0.014). There were no significant differences between the groups for adhesive residues after polishing (p_i ≥ 0.628). Adhesive residues, if present, were only detectable by OCT and covered less than 1% of the enamel surfaces evaluated.

Conclusion: Tube removal did not cause clinically relevant enamel damage such as chipping or cracking.

Purpose: The scope of the present study was to create a new harmony box by adding two diagnostically and clinically important cephalometric variables, the gonial and interincisal angles, while also considering the effect of sex and age for a growing Swiss population.

Methods: A healthy sample with an overjet and overbite between 2 and 4 mm, and 1.5 and 4.5 mm, respectively, of the Zurich Craniofacial Growth Study was considered. Pairwise correlations between the cephalometric angles were evaluated with the Pearson correlation coefficient (r). Regression models were built for each cephalometric variable serving as the dependent one. The Akaike Information Criterion and the Bayesian Information Criterion were used to structure and select the final multivariable regression model. Bland-Altman plots and the Lin's concordance correlation coefficient were used to assess inter- and intraexaminer agreement.

Results: The sample consisted of 301 individuals with a mean age of 13.4 years. Measurement concordance was confirmed both within and between examiners. The strongest correlations were observed between the angles SNB and SNA (r = 0.81), ArGoMe and SN-ML (r = 0.57), and SN-ML and SNB (r = 0.56). The SNB angle qualified as the dependent variable in the multivariable regression that framed the newly provided harmony box, with the predictor variables age (p < 0.001) and the angles SNA (p < 0.001), SN-ML (p < 0.001), SN-NL (p = 0.005), NSBa (p = 0.001), and ArGoMe (p < 0.001). The interincisal angle did not increase the robustness of the model and was excluded (p > 0.05).

Conclusion: Contrary to the interincisal angle, gonial angle and age qualified for inclusion in the new harmony box for individualized cephalometrics in a sample of healthy schoolchildren from Zurich, Switzerland.

For accurate interpretation of quantitative real-time PCR (qPCR) data, stable reference genes are essential for normalization of target genes. To date, there is no information on reliable housekeeping genes in CD4+ T cells in a three-dimensional (3D) matrix under pressure stimulation. This in vitro study describes for the first time a method for pressure stimulation of CD4+ T cells in a 3D matrix in the context of orthodontic tooth movement (OTM) and identifies a set of reliable reference genes. CD4+ T cells were isolated from murine spleen and activated with anti-CD3/-CD28 Dynabeads (Thermo Fisher, Langenselbold, Germany) on standard cell culture plates or in 3D scaffolds with or without compressive strain. Expression stability of nine potential reference genes was examined using four mathematical algorithms. Gene expression of Il2 was normalized to all potential reference genes to highlight the importance of correct normalization. Cell proliferation and the expression of the surface markers CD25 and CD69 were also determined. The 3D matrix did not inhibit proliferation after immunological activation of T cells and embedded the cells sufficiently to expose them to pressure load. Expression of ubiquitin C (Ubc) and hypoxanthine phosphoribosyltransferase (Hprt) was the most stable under all conditions tested. A combination of these two genes was suitable for normalization of qPCR data. Normalization of Il2 gene expression showed highly variable results depending on the reference gene used. Pressure reduced cell proliferation and the number of CD69-positive T cells. This study provides a basis for performing valid and reliable qPCR experiments with CD4+ T cells cultured in 3D scaffolds and exposed to compressive forces simulating OTM.

Objective: To assess the remodeling effects of protraction facemask therapy on the trabecular pattern of the mandible and identify quantitatively the regions of the mandible undergoing maximum changes in the trabecular pattern.

Materials and methods: The retrospective study was conducted in 30 subjects divided into two groups. The treatment group (group 1) consisted of 15 subjects with skeletal class III malocclusion treated with a facemask (mean age: 9.1 ± 2.1 years). Digital panoramic radiographs (OPG) were obtained before treatment (T0) and at the end of active facemask therapy (T1) with a mean duration of 16.1 ± 2.5 months. In all, 15 skeletal class I subjects who did not undergo any orthodontic treatment (mean age 9.1 ± 2.2 years) comprised the control group (group 2) who had two OPGs at a mean interval of 13.6 ± 2.2 months. The fractal dimensional (FD) value was calculated in three regions: angular, condylar, and corpus region.

Results: Intragroup comparisons revealed a significant increase in the FD values in the right condylar (T0 = 1.2 ± 0.2; T1 = 1.4 ± 0.1) and left condylar (T0 = 1.2 ± 0.1; T1 = 1.4 ± 0.1) region (p < 0.05) and in the corpus region (FD values: right T0 = 1.2 ± 0.1, T1 = 1.4 ± 0.1; left T0 = 1.2 ± 0.1, T1 = 1.4 ± 0.1; p < 0.05). The intergroup comparison demonstrated that the treatment group showed greater changes compared with the controls in the condylar process (mean difference: right = 0.19, left = 0.20; p < 0.05) and the corpus region (0.172; p < 0.05).

Conclusion: FD analysis demonstrated that the condylar process and the corpus region underwent the most significant change in the trabecular pattern in subjects treated with protraction facemask therapy.

Purpose: The aim of this study was to evaluate the extent of property changes caused by heating the distal portion of heat-activated nickel-titanium (NiTi) wires.

Methods: Forty preformed heat-activated NiTi archwires (3M Unitek, Monrovia, CA, USA) with a nominal cross-section of 0.018″ were used in this study. The archwires were divided into a control group, not submitted to heat treatment and, thus, maintaining the as-received properties, and an experimental group, in which the archwires were submitted to heat treatment for distal bending at one end. Wire segments of control and experimental groups were submitted to differential scanning calorimetry (DSC) and Vickers microhardness measurements.

Results: The DSC results suggest local recrystallization and precipitate dissolution at the heat-treated tip, which decreases as the distance to the wire's tip increases. Vickers microhardness tests revealed significant changes for distances between 6 and 8 mm from the wire's tip. Heating the distal portion of heat-activated NiTi archwires should be performed with care since this clinical procedure may compromise the performance of these wires to a distance of 8 mm from the archwire end.

Conclusion: Heat treatment for distal bending in heat-activated NiTi archwires may be performed, with little impact on the areas adjacent to heat treatment. In cases presenting molars requiring significant orthodontic corrections, it should be preferred to apply other techniques to avoid archwire sliding, such as crimpable stops, or to have flame control to avoid placing a heat-treated section in the tubes of these molars.

Purpose: To ascertain the relationship between malocclusion severity, treatment expectations, socioeconomic status, objective orthodontic treatment need, and oral health-related quality of life (OHRQoL) in adolescents with class II malocclusion.

Methods: Cephalometric measurement values, arch discrepancy values, and clinical examination findings were recorded to determine the severity of malocclusion in 104 adolescents with class II malocclusion who requested orthodontic treatment. Objective orthodontic treatment need was determined by the Index of Complexity, Outcome, and Need (ICON) and Dental Aesthetic Index (DAI) scores. The Psychosocial Impact of Dental Aesthetic Questionnaire (PIDAQ) and the Oral Health Impact Profile-14 (OHIP-14) were used to assess the OHRQoL. Treatment expectations and the socioeconomic status were also evaluated.

Results: Patients with proclined upper incisors exhibited higher PIDAQ scores than those with retroclined upper incisors. Contrary, no significant difference was observed between the PIDAQ and OHIP-14 scores of the patients categorized according to overjet, overbite, growth pattern, or objective orthodontic treatment need. No statistically significant correlation was identified between socioeconomic status, OHRQoL, age, and DAI scores, except for socioeconomic status and ICON scores. Patients who reported the treatment expectation to improve their social relationships and communication skills exhibited the highest OHIP-14 scores, indicating the poorest OHRQoL.

Conclusion: Significantly poorer OHRQoL was observed in adolescents with class II malocclusion who presented an increased proclination of their upper incisors and requested orthodontic treatment with the expectation of improvement in social relations and communication skills. Larger study samples would improve the generalizability of the results.