Journal of the World Federation of Orthodontists最新文献

Plastic aligners have transformed orthodontics, offering a discreet, comfortable, and aesthetically pleasing alternative to traditional fixed appliances. While they have advantages over fixed appliances, they come with environmental and health concerns due to the use of nonbiodegradable plastics, such as the leaching of Bisphenol-A (BPA) and microplastics that can impact human health directly through ingestion. Studies have shown that plastic aligners release microplastics during use, raising concerns about their potential health effects and environmental pollution. The potential health effects of ingested microplastics extend beyond gut microbiota disruption to impact various systems in the body. Research suggests that microplastic exposure can lead to respiratory complications, cardiovascular risks, and implications for brain health and cognitive function. The mechanisms of microplastic uptake into the body through inhalation, ingestion, and skin contact are essential for understanding how these particles interact with human tissues and organs. By prioritizing patient safety, responsible practices, and advancing scientific knowledge the orthodontic community can work towards mitigating the potential health impacts associated with microplastic exposure from aligners.

Background: Using miniscrews to control anchorage made the application of force for various orthodontic treatment approaches easier and increased their effectiveness. Some problems may occur during the use of miniscrews, such as peri‑implant mucositis, mobility, postoperative pain, and failure. This study compared the success rate of miniscrews coated with chlorhexidine hexametaphosphate antimicrobial nanoparticles with that of uncoated miniscrews.

Methods: In a double-blind randomized controlled clinical trial using a split-mouth design, 80 miniscrews were inserted symmetrically into 40 individuals between the maxillary second premolar and first molar. Random allocation software was used to distribute the coated and uncoated miniscrews. The patients were monitored monthly, for a duration of 4 months. The main measure of interest was the success rate of miniscrews, which was assessed throughout follow-up periods of up to 4 months. The secondary objective was the assessment of the mobility of the miniscrews, peri‑implant health, and pain perception. A Wilcoxon signed-rank test and Kaplan-Meier survival analysis were applied to analyze the data.

Results: Main outcome: After the 4-month follow-up, the success rates of the miniscrews for coated and uncoated samples were 81.3% and 84.4%, respectively, which was a statistically insignificant difference.

Secondary outcome: Mobility and peri‑implant health were not statistically different between the coated and uncoated miniscrew groups. Pain intensity was rated higher on the first day, then decreased gradually, diminishing completely on the sixth and seventh day. However, the pain perception between the coated and uncoated miniscrews did not differ statistically.

Conclusions: Chlorhexidine-hexametaphosphate nanoparticles did not increase the success rate and stability, nor did they enhance peri‑implant health or affect pain perception during the short observation period.

Trial registration: This trial was registered at ClinicalTrials.gov; ID: NCT06124235.

This case report describes the successful orthodontic management of a 25-year-old female patient presenting with Class II Division 2 malocclusion, moderate maxillary anterior crowding, and a missing mandibular left first molar. Treatment plan involved extraction of two maxillary first premolars to address crowding and protraction of two mandibular left molars, combined with the strategic use of mini-implants for precise tooth movement control. Ridge-split surgery was adopted to manage alveolar ridge resorption in the edentulous area. This procedure was essential for widening the narrow alveolar ridge, thereby reducing resistance and facilitating the mesial movement of two mandibular left molars. Lingual and labial biomechanics, including linguoincisal elastics and a cantilever system, were utilized to optimize torque control and molar protraction. Clear aligners were employed throughout the treatment phases, navigating challenges such as the closure of extraction spaces and achieving stable buccal interdigitation. The treatment spanned 4 years, using a total of 175 aligners. The initial phase required 66 aligners to close maxillary extraction spaces and the mandibular edentulous space, followed by 52 aligners in the first refinement and 57 aligners in the second refinement phase. Posttreatment evaluations demonstrated successful alignment of dental arches, correction of malocclusion, and enhancement of facial aesthetics. This case highlights the efficacy of integrated orthodontic techniques in achieving comprehensive functional and aesthetic outcomes in complex orthodontic cases.

Introduction: Advancements in technology have led to the adoption of digital workflows in dentistry, which require the segmentation of regions of interest from cone-beam computed tomography (CBCT) scans. These segmentations assist in diagnosis, treatment planning, and research. However, manual segmentation is an expensive and labor-intensive process. Therefore, automated methods, such as convolutional neural networks (CNNs), provide a more efficient way to generate segmentations from CBCT scans.

Methods: A three-dimensional UNet-based CNN model, utilizing the Medical Image Segmentation CNN framework, was used for training and generating predictions from CBCT scans. A dataset of 351 CBCT scans, with ground-truth labels created through manual segmentation using AI-assisted segmentation software, was prepared. Data preprocessing, augmentation, and model training were performed, and the performance of the proposed CNN model was analyzed.

Results: The CNN model achieved high accuracy in segmenting maxillary and mandibular teeth from CBCT scans, with average Dice Similarity Coefficient values of 91.83% and 91.35% for maxillary and mandibular teeth, respectively. Performance metrics, including Intersection over Union, precision, and recall, further confirmed the model's effectiveness.

Conclusions: The study demonstrates the efficacy of the three-dimensional UNet-based CNN model within the Medical Image Segmentation CNN framework for automated segmentation of maxillary and mandibular dentition from CBCT scans. Automated segmentation using CNNs has the potential to deliver accurate and efficient results, offering a significant advantage over traditional segmentation methods.

Background: While orthodontic miniscrews have been widely documented for their successful application, limited research exists on the stability and effectiveness of reused miniscrews. This systematic review aims to evaluate the stability and effectiveness of reused miniscrews in orthodontic treatments.

Methods: An electronic search was conducted for studies published up to February 2024 across MEDLINE, Web of Science, EMBASE, Scopus, and Cochrane CENTRAL. Additionally, gray literature sources and manual searches of prominent orthodontic journals from 2010 to 2023, were also examined. Studies that investigated the use of miniscrews after retrieval and sterilization involving both in vitro studies and clinical trials were included.

Results: From 946 searched studies, 18 were finally included in our review. Thirteen studies investigated retrieved and sterilized miniscrews, while five examined unused and sterilized miniscrews to isolate the effects of sterilization. After performing a meta-analysis on in vitro studies, no significant difference in insertion, removal, or fracture torque between retrieved and unretrieved miniscrews was found, though sterilized miniscrews had a statistically significant increase in insertion torque without affecting fracture resistance. Meta-analysis of clinical studies revealed that retrieved miniscrews exhibited a significantly higher failure rate with a risk ratio of 0.46 (95% confidence interval = 0.24, 0.69), indicating a higher likelihood of failure on reuse.

Conclusion: There were no significant differences in insertion and fracture torque between new and reused miniscrews. However, reused miniscrews were associated with a higher failure rate. This outcome may be influenced by factors such as sterilization methods, insertion technique, and patient-specific anatomical considerations.

Aim: This study employed a quantitative approach to compare the reliability of responses provided by ChatGPT-3.5, ChatGPT-4, and Google Gemini in response to orthognathic surgery-related questions.

Material and methods: The authors adapted a set of 64 questions encompassing all of the domains and aspects related to orthognathic surgery. One author submitted the questions to ChatGPT3.5, ChatGPT4, and Google Gemini. The AI-generated responses from the three platforms were recorded and evaluated by 2 blinded and independent experts. The reliability of AI-generated responses was evaluated using a tool for accuracy of information and completeness. In addition, the provision of definitive answers to close-ended questions, references, graphical elements, and advice to schedule consultations with a specialist were collected.

Results: Although ChatGPT-3.5 achieved the highest information reliability score, the 3 LLMs showed similar reliability scores in providing responses to orthognathic surgery-related inquiries. Moreover, Google Gemini significantly included physician recommendations and provided graphical elements. Both ChatGPT-3.5 and -4 lacked these features.

Conclusion: This study shows that ChatGPT-3.5, ChatGPT-4, and Google Gemini can provide reliable responses to inquires about orthognathic surgery. However, Google Gemini stood out by incorporating additional references and illustrations within its responses. These findings highlight the need for an additional evaluation of AI capabilities across different healthcare domains.

Background: This study used cone-beam computed tomography (CBCT) via voxel-based superimposition to evaluate lip and incisor changes after orthodontic treatment with four premolar extractions (Ext) versus nonextraction (Non-Ext) among African American (AA) and White (W) patients.

Methods: A total of 240 CBCTs of 120 adolescent orthodontic patients with Class I skeletal/dental relationships were included. Patients were initially divided according to treatment, and then each group was subdivided according to patients' ethnicity (Ext/W = 30, Ext/AA = 30, Non-Ext/W = 30, and Non-Ext/AA = 30). CBCTs were imported into Invivo6 for voxel-based superimposition. Lip and incisor measurements were recorded. Independent t tests and two-way ANOVA were used for statistical assessment.

Results: The Non-Ext/W group had a greater increase in all outcome variables compared with the Non-Ext/AA group, with a significant change in volume and position of upper (UL) and lower lips (LL), inclination of upper (U1) and lower incisors (L1), and position of U1. The Ext/AA group had a greater decrease in all measured outcomes compared with the Ext/W group, with significant change in inclination of U1 and L1, and position and volume of LL. W patients had more crowding than AA patients in both treatment approaches. Retraction ratios of 6.5:1 and 2.1:1 were recorded between the U1 and UL positions, and L1 and LL positions, respectively. There were no direct interaction effects between ethnicity and treatment, nor were there any significant effects of ethnicity after controlling for the covariates.

Conclusions: Ethnicity alone has no impact on incisor and lip position after treatment. However, ethnicity in the form of initial presentation of malocclusion can have a significant influence.

Background: The objective was to systematically review studies assessing the efficacy of clear aligner therapy (CAT) and miniscrew-anchored fixed appliances (MAFAs) in the correction of skeletal and dental open bite in the permanent dentition.

Methods: A literature search was conducted across different databases, including PubMed, Cochrane Library, Science Direct, Web of Science, Medline, Scopus and Google Scholar, up to April 2024. Studies were chosen based on prespecified inclusion criteria. The dentoskeletal changes based on lateral cephalometry were evaluated from the included papers. Study selection, data extraction, and risk of bias (RoB) assessment were performed in duplicate. Risk of bias assessment was done using ROBINS-I (Risk of Bias in Non-Randomized Studies of Interventions) and Cochrane RoB 2 tools. GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessed certainty of evidence.

Results: Out of the 22 studies that were selected, 13 papers covered MAFAs, while 9 articles focused on CATs. Since the included papers consist of prospective and retrospective observational studies, as well as two randomized controlled trials, the scientific evidence is at a low level. CATs primarily induced posterior teeth intrusion and anterior teeth extrusion, contributing to the reduction of the posterior vertical dimension and improved occlusal contacts. Conversely, MAFAs facilitated significant molars intrusion, and controlled anterior teeth extrusion, effectively addressing both dental and skeletal discrepancies.

Conclusions: This review supports the use of MAFAs and CATs for treating skeletal and dental open bite, highlighting their effectiveness and implications for orthodontic practice. The limitations of this study should be considered when interpreting the results.

Background: The retrospective study examined changes in the root length and alveolar bone surrounding maxillary incisors in patients with skeletal Class III malocclusion treated by surgical orthodontic treatment with either fixed appliances (FAs) or clear aligners (CAs).

Methods: A total of 60 subjects were divided based on appliance type used. Cone beam computed tomography scans were taken at three stages: before treatment, after presurgical orthodontic treatment, and post-treatment for both groups. Vertical alveolar bone level and horizontal alveolar bone thickness (ABT) were measured at four heights (3, 6, and 9 mm from the cementoenamel junction, and the root apex), along with root length, at these time points.

Results: Both groups showed a decrease in root length, with the CA group experiencing a significantly smaller reduction (0.4 ± 0.79 mm) compared with the FA group (0.64 ± 0.8 mm; P = 0.02). The FA group demonstrated more significant reduction in palatal ABT (P < 0.05) and greater root resorption, whereas the CA group exhibited considerable labial marginal bone resorption (P = 0.007) and a notable decrease in labiolingual inclination (P = 0.042).

Conclusions: The findings suggest that FA and CA might lead to decreased ABT and significant root resorption, with FA therapy likely resulting in more pronounced effects. Both modalities led to notable vertical bone loss, particularly, on the labial side of the maxillary incisors in the CA group during postsurgical orthodontic treatment. Preventing iatrogenic deterioration of periodontal support surrounding the incisors is crucial during presurgical and postsurgical phases.

Background: The aim of this study was to evaluate the alveolar crestal bone height, alveolar bone thickness, and root resorption in mandibular incisors after fixed orthodontic treatment.

Methods: A total of 35 patients (mean age 17.02 ± 3.24 years) with moderate to severe mandibular anterior crowding requiring first premolar extraction were included. Cone beam computed tomography scans of the mandibular anterior region were obtained from the patients before and after orthodontic treatment. The alveolar crestal bone height, cortical bone thickness (CBT) (at apex and midroot level), labial and lingual alveolar bone thickness, and root resorption were assessed for all mandibular incisors. Paired Student's t test was used to compare pretreatment and post-treatment alveolar bone changes and root resorption.

Results: A significant decrease in lingual crestal bone height was observed in all mandibular incisors after orthodontic treatment (P < 0.001). Lingual CBT decreased at the midroot level significantly for all mandibular incisors after completion of orthodontic treatment (P < 0.001). A significant decrease in total lingual bone thickness was observed in all mandibular incisors (P < 0.001). Root lengths of mandibular incisors decreased significantly in the sagittal and coronal sections after orthodontic treatment (P < 0.001).

Conclusions: Fixed orthodontic treatment with premolar extraction results in a significant reduction of alveolar crestal bone height, CBT (at midroot level), and alveolar bone thickness on the lingual aspect of mandibular incisors. Significant orthodontically induced inflammatory root resorption was observed in all mandibular incisors after orthodontic treatment.