Journal of Orofacial Orthopedics-Fortschritte Der Kieferorthopadie最新文献

Purpose: This study aimed to evaluate the accuracy of different mixed dentition analysis methods in predicting the mesiodistal diameters (MDD) of unerupted permanent canines and premolars (PCP) in a Turkish population and to determine the most reliable method for clinical application.

Methods: This research represents a retrospective, population-based cross-sectional study. Seven commonly used maxilla (Mx) and mandible (Md) unerupted PCP mesiodistal diameter prediction methods (Tanaka-Johnston, Moyers, Tränkmann, Legovic, Gross-Hasund, Bachmann, and Melgaço methods) were compared. The study included 120 Turkish children (60 males, 60 females) aged 13-16 years. MDD was measured using digital dental models. The predicted values were analyzed for accuracy by comparing them with the actual tooth diameters. Statistical analyses assessed the differences between the methods and their reliability in male and female subjects.

Results: For the investigated Turkish population, the Gross-Hasund (Mx female: 0.32 ± 1.07 mm; Mx male: 0.22 ± 0.79 mm; Md female: 0.29 ± 0.79 mm; Md male: 0.55 ± 0.80 mm) and Bachmann methods (Mx female: 0.26 ± 1.04; Mx male: 0.24 ± 0.82 mm; Md female: 0.17 ± 0.72 mm; Md male: 0.52 ± 0.83 mm) provided the most accurate predictions, with minimal deviation from actual tooth sizes. The Tanaka-Johnston and Moyers methods tended to overestimate tooth sizes in males and underestimate them in females. The Tränkmann method showed the highest prediction error, particularly in males (Mx: 2.98 ± 1.40 mm; Md: 3.05 ± 0.78 mm). Sex differences were statistically significant in most methods, highlighting the necessity for population- and sex-specific adjustments in mixed dentition analyses.

Conclusion: The findings suggest that currently available prediction methods may not fully apply to the Turkish population without modifications. The Gross-Hasund and Bachmann methods were the most dependable, whereas the Tränkmann method showed significant discrepancies. Developing population-specific regression equations may improve the accuracy of mixed dentition analysis and enhance orthodontic treatment planning in Turkish individuals.

Purpose: This study aimed to compare the accuracy of orthodontic tooth movements achieved with three-dimensionally (3D) printed aligners (Noxi, Sweden&Martina, Due Carrare, Padova, Italy) using a 12 h/day protocol with that of thermoformed aligners (F22 aligner, Sweden&Martina, Due Carrare, Padova, Italy) using a 22 h/day protocol.

Methods: Of the 40 white adult patients (12 men and 28 women, mean age 30.1 years) undergoing orthodontic treatment with aligners selected based on specific inclusion criteria, 20 patients were treated with Noxi aligners using a 12 h/day protocol (study group), and the remaining 20 patients were treated with F22 aligners using a 22 h/day protocol (control group). Pretreatment, ideal posttreatment (as planned in the setup), and real posttreatment digital models were analyzed using VAM software (Vectra, Canfield Scientific, Fairfield, NJ, USA). Angular and linear measurements were evaluated to measure mesiodistal tipping, vestibulolingual tipping, and rotational movements for 1120 teeth. Data were compared to evaluate treatment accuracy for each tooth, with statistical analysis of the results.

Results: No statistically significant differences in accuracy emerged between the study group (64.2%) and the control group (65.4%) for any type of tooth movement or tooth category. In the study group, vestibulolingual tipping showed the highest predictability (69.63%), followed by mesiodistal tipping (65.38%) and rotation (60.5%). In the control group, the vestibulolingual and mesiodistal movements showed the highest predictability, with a mean accuracy of about 67%, followed by rotation (62.3%).

Conclusion: Despite the reduced collaboration request, the group treated with Noxi aligners did not show any significant differences compared to the group treated with F22 aligners with regard to percentage accuracy for all analyzed orthodontic movements.

Purpose: The indication for orthodontic treatment in children and adolescents is based on severity of tooth and jaw malocclusions that lead to limitations in oral health-related quality of life (QoL). We have already shown how overbite and overjet deviations negatively affect QoL. However, few studies have investigated the influence of anterior crowding in the upper jaw on QoL.

Methods: We selected 734 children and adolescents aged 11-14 years from a population-based longitudinal cohort study (LIFE Child). The data used in this study were retrospectively analyzed. Evaluable jaw models were available for 554 subjects in which we performed three orthodontic space analyses: (i) purely visual assessment of the crowding of the incisors in the upper jaw (VA), (ii) the Little index (LI), and (iii) the Lundström analysis (LA). Limitations in QoL were determined using the German version of the Child Perceptions Questionnaire (CPQ-G-11-14), taking into account the effects of age, gender, socioeconomic status (Winkler score), orthodontic treatment, oral hygiene, overbite/overjet, and dental caries (decayed, missing, filled teeth [DMFT] index) as possible influencing factors.

Results: The percentage of individuals with crowding in our cohort was 11% according to VA, 14.3% according to LI, and 7.3% according to the LA. Within the three analyses, the groups of individuals with crowding did not fully overlap. The CPQ score (subscales: "emotional and social well-being") was significantly higher in subjects with crowding independent of the type of crowding analysis (p < 0.05), gender, or socioeconomic status (multivariable linear regression analysis).

Conclusion: Children and adolescents with crowding had significantly more QoL impairments, especially related to emotional and social well-being. It is necessary to perform more than one crowding analysis in order to find more affected individuals with a reduced QoL due to crowding.

Purpose: The effects of caffeine on bone metabolism and orthodontic tooth movement are largely inconsistence. This study investigated the dual effect of caffeine on receptor activator of nuclear factor κΒ ligand (RANKL)-induced osteoclastogenesis in RAW 264.7 cells and the role of adenosine receptors in these effects.

Methods: RAW 264.7 cells were treated with RANKL with or without 1-300 μM of caffeine. Cell viability and the numbers of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were evaluated. The effect of caffeine on osteoclast activity was validated by bone resorption assays to measure the release of a fluorescent probe, resorption pit areas, and visualization by scanning electron microscope (SEM). The role of adenosine receptor (AR) subtypes in caffeine-, inducing or -inhibiting osteoclast differentiation were analyzed using AR antagonists.

Results: Caffeine at concentrations 1-100 μM did not affect cell viability. The number of TRAP positive cells, which represent osteoclast differentiation, increased with RANKL treatment and further increased with low concentrations of caffeine (1-10 µM). However, higher concentrations (30-300 µM) inhibited RANKL-induced TRAP formation. Similarly, the release of fluorescent probes and the formation of resorption pit areas, which represented osteoclast activity, increased at low concentrations and were reduced at high concentrations of caffeine. SEM micrographs demonstrated a pattern similar to the pit assay. In addition, the A_2AR antagonist tended to increase osteoclast differentiation, while the A₁R antagonist inhibited the caffeine effect.

Conclusion: Caffeine has a dual effect depending on the concentration. At low concentrations, caffeine enhanced osteoclast differentiation and activity, while higher concentrations diminished osteoclastogenesis. The A₁R receptor may be responsible for caffeine-induced osteoclast differentiation.

Objective: To comparatively evaluate the in vitro cytotoxicity of three commercially available silver solder materials in different forms-traditional silver solder with flux, silver solder incorporated with flux, and silver solder paste with flux-on Balb/c 3T3 fibroblast cell lines.

Materials and methods: Ninety-six samples were categorized into four groups: group 1 (only cell culture medium), group 2 (silver solder + flux), group 3 (universal silver solder), and group 4 (silver solder paste with flux). Each group had 24 samples assessed at three intervals: 24 h (T1), 7 days (T2), and 30 days (T3). Cytotoxicity was evaluated using the neutral red uptake assay, measuring optical density at 540 nm. Data were analyzed using one-way analysis of variance (ANOVA), Tukey's post hoc test, and paired t‑tests (p < 0.05).

Results: All test groups exhibited increased cytotoxicity over time, with the highest toxicity observed at 24 h. Group 4 (solder paste with flux) showed the greatest cytotoxicity (96.75% nonviable cells), followed by group 2 (76.13%) and group 3 (71.83%). The control group showed minimal change (16.4%). ANOVA revealed significant differences between groups at all-time points (p < 0.001). Post hoc analysis confirmed that the solder paste group was significantly more cytotoxic than the others. Time-dependent reductions in cell viability were observed, particularly between T2 and T3.

Conclusion: All tested silver solder materials demonstrated cytotoxic effects on Balb/c 3T3 fibroblasts. The silver solder and flux displayed the lowest cytotoxicity, followed by universal silver solder, and silver solder paste with flux demonstrating the highest cytotoxicity. These findings highlight the need for careful material selection in orthodontic appliance fabrication to minimize adverse biological effects.

Purpose: The aim of this study was to investigate the difference in enamel loss, composite residue, and time during removal of fixed orthodontic retainers using ultraviolet (UV) light compared to standard white light.

Methods: A nickel-chromium retainer was bonded to 4 bovine teeth using a fluorescence-modified composite (Aligner Flow Composite, Voco, Cuxhaven, Germany); 20 models were created. In a split-mouth design, 2 teeth per retainer were removed using standard white light (non-FIT) and 2 teeth using the fluorescence-aided identification technique (FIT) with UV light. Removal time was recorded for each tooth. Intraoral and optical coherence tomography (OCT) scans were taken of the tooth before bonding (T0) and after retainer removal (T1). The intraoral scans were analyzed using the software Avizo to quantify enamel loss (T0-T1) and composite residue (T1-T0). The OCT scans were evaluated using a dichotomous scoring system for enamel loss and a four-point scoring system for composite residue.

Results: There was no significant difference in removal time for the two groups. The overlay of intraoral scans showed significantly less enamel loss in area (39.35 ± 39.98 mm² vs. 65.44 ± 58.11 mm², p = 0.0235) and volume (3.41 ± 6.15 mm³ vs. 8.86 ± 11.65 mm³, p = 0.0116), as well as less composite residue in area (8.22 ± 16.04 mm² vs. 30.87 ± 49.65 mm², p = 0.0083) and volume (0.41 ± 0.87 mm³ vs. 2.34 ± 3.94 mm³, p = 0.0037) in the FIT group compared to standard white light. While OCT scans showed no significant difference in enamel loss, it proved that the amount of composite residue was significantly less in the FIT group compared to the standard light controls (5.88 ± 10.54 vs. 22.66 p = 0.0072).

Conclusion: Although the FIT method does not reduce the removal time of orthodontic fixed retainers, it has been shown to be beneficial in preserving enamel and leaving less composite residue.

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.