Orthodontics & Craniofacial Research最新文献

Introduction: Dental imaging comprises a wide range of techniques and modalities, each with different diagnostic features influenced by numerous parameters, all of which contribute to the precision and effectiveness of dental evaluations and treatments. This study examined the dimensional reproducibility of arch measurements from CBCT scans with different voxel sizes and exposure parameters compared to a reference model from Extra-oral scanners (EOS) and how these parameters affected digital matching and diagnostic image quality.

Methods: A diagnostic observational study of arch dimensions, including inter-canine, inter-premolar, intermolar, arch width and arch length, was conducted on digital models (DMs) created from 65 CBCT scans of a full dentate epoxy maxillary model. The measurements obtained from EOS scans served as the control for the study. Normality was tested with the Shapiro-Wilk test, comparisons used the Kruskal-Wallis test with Bonferroni-adjusted pairwise comparisons for significant results, and data were analysed using IBM SPSS (Version 26.0), with significance set at p < .05.

Results: Significant deviations were revealed among study groups, with group I (smallest voxel size) consistently displaying the lowest values, mean (SD) deviation was reported as 0.01 (0.006) and group IV (lowest kV value) exhibiting the highest deviations, mean (SD) deviation of 0.16 (0.17).

Conclusion: Combining a small voxel size (0.12 mm) with high milliampere (8 mA) and kilovoltage (90 kV) settings in CBCT ensured detailed anatomical visualization and accurate linear measurements, crucial for precise dental assessments, and emphasizing the necessity for strict control over CBCT parameters in dental applications.

Accelerating orthodontic tooth movement (OTM) is increasingly important for shorter treatment times, which reduces periodontal risks, root resorption and dental caries. Techniques to accelerate OTM focus on stimulating bone remodelling by enhancing osteoclast and osteoblast activity and include both surgical and non-surgical methods. The therapeutic potential of ultrasounds is highly recognized among many medical areas and has shown promising results in modulating bone remodelling and inflammation phenomena. This systematic review aims to collect and analyse the current scientific in vitro and ex vivo evidence on ultrasound stimulation (US) bioeffects in cells implicated in tooth movement. This review was conducted according to PRISMA 2020 guidelines. A bibliographic search was carried out in the PubMed, Scopus and Web of Science databases. Sixteen articles were selected and included in this review. The revised studies suggest that US of 1.0 and 1.5 MHz, delivered at 30 mW/cm², 10 to 30 min daily over three to 14 days seems to be effective in promoting osteoclastogenic activity, while US of 1.5 MHz, 30 to 90 mW/cm², in 5- to 20-min sessions delivered daily for 5 to 14 days exhibits the potential to stimulate osteogenic activity and differentiation. Previous research yielded varied evidence of the effectiveness of US in orthodontics. Future animal studies should employ the recommended US parameters and investigate how distinct protocols can differentially impact tissue remodelling pathways. The knowledge arising from this review will ultimately potentiate the application of US to accelerate OTM in the clinical setting.

Objectives: The objective of this study was to determine changes in gene expression by establishing an orthodontic tooth movement (OTM) rat model with appropriate and excessive orthodontic force.

Materials and methods: Using a closed coil nickel-titanium spring, the OTM was carried out to apply a mesial force of 50 or 100 g to the maxillary first molars. Micro-CT, histological and immunohistochemical staining were used to evaluate the bone formation at the tension site and the bone resorption and bone formation at pressure site. Then RNA sequencing and bioinformatic analysis were performed.

Results: According to the results of the Mirco-CT scan of OTM rat models, both the 50 g group and the 100 g group showed variable degrees of reduction in alveolar bone density on the tension and pressure sides. The results of histological and immunohistochemical staining demonstrated that the periodontal tissue and osteogenic ability of the 50 g group were restored at the 14 days, while the 100 g group caused severe periodontal tissue damage. The GO and KEGG analysis results, as well as the number of differentially expressed genes (DEGs), varied depending on the loading time and value of appliance, according to the results of the RNA sequencing. And the immunohistochemical staining results showed that Sfrp4 functioned by efficiently influencing both bone formation and bone absorption.

Conclusions: Appropriate orthodontic force value could cause appropriate movement of teeth in rats without adverse periodontal damage. Simultaneously, distinct gene expression patterns were observed at various force levels and time intervals.

A "spontaneous" correction of the Class II malocclusion has been described after maxillary expansion (ME) treatment. The aim of the present review was to systematically summarize changes in the sagittal dentoskeletal parameters of growing Class II patients after ME. The study protocol was developed according to the PRISMA statement and registered in PROSPERO before literature search, data extraction and analysis. The PICO model was followed in the definition of the research question, search strategies and study selection criteria. Randomized and non-randomized studies on the sagittal effects of ME published in English language without date restrictions were electronically searched across the Cochrane Library, Scopus and MEDLINE/PubMed databases. Changes in sagittal dentoskeletal cephalometric parameters were analysed. The risk of bias in randomized and nonrandomized studies was assessed using the Rob2 and ROBINS-I tools, respectively. A narrative synthesis was performed, focusing on the investigated population, intervention, comparison, and main outcomes. Pairwise meta-analyses were used to compare the outcomes assessed in subjects who underwent ME versus untreated subjects. Ten studies met the inclusion criteria, four were included in the pairwise meta-analyses due to the presence of a control group. Slight but significant improvements in OVJ (MD: -0.36; 95%; CI [-0.69 to -0.01]; p = .04) and 6/6 molar relation (MD: 1.5; 95%; CI [0.69 to 1.61]; p < .0001) were found in patients who underwent ME compared with untreated subjects, whereas no improvement in skeletal parameters was observed. However, the limitations of a small body of moderate-quality evidence and possible confounding factors should be considered. Evidence on the sagittal skeletal and dental effects of ME in Class II patients is still ambiguous, suggesting the need for more clinical trials, including appropriate control subjects, randomization and blinding during outcome assessment.

Objectives: To predict palatally impacted maxillary canines based on maxilla measurements through supervised machine learning techniques.

Materials and methods: The maxilla images from 138 patients were analysed to investigate intermolar width, interpremolar width, interpterygoid width, maxillary length, maxillary width, nasal cavity width and nostril width, obtained through cone beam computed tomography scans. The predictive models were built using the following machine learning algorithms: Adaboost Classifier, Decision Tree, Gradient Boosting Classifier, K-Nearest Neighbours (KNN), Logistic Regression, Multilayer Perceptron Classifier (MLP), Random Forest Classifier and Support Vector Machine (SVM). A 5-fold cross-validation approach was employed to validate each model. Metrics such as area under the curve (AUC), accuracy, recall, precision and F1 Score were calculated for each model, and ROC curves were constructed.

Results: The predictive model included four variables (two dental and two skeletal measurements). The interpterygoid width and nostril width showed the largest effect sizes. The Gradient Boosting Classifier algorithm exhibited the best metrics, with AUC values ranging from 0.91 [CI95% = 0.74-0.98] for test data to 0.89 [CI95% = 0.86-0.94] for crossvalidation. The nostril width variable demonstrated the highest importance across all tested algorithms.

Conclusion: The use of maxillary measurements, through supervised machine learning techniques, is a promising method for predicting palatally impacted maxillary canines. Among the models evaluated, both the Gradient Boosting Classifier and the Random Forest Classifier demonstrated the best performance metrics, with accuracy and AUC values exceeding 0.8, indicating strong predictive capability.

Background: Orthodontically induced inflammatory root resorption (OIIRR) is one of the most important side effects of orthodontic treatment. Low-level laser therapy (LLLT) is a useful way to reduce the orthodontic treatment duration and may have some effect on preventing and repairing OIIRR. However, the specific effects of LLLT on OIIRR remain unknown.

Objective: Our research aimed to evaluate the Dentin Sialophosphoprotein (DSPP) expression level and root resorption volume during treatment and retention to explore the role of LLLT in preventing and repairing OIIRR.

Methods: Thirty-seven 6-week-old male Sprague-Dawley rats were selected to establish an OIIRR model; the rats were divided into Group B (blank), Group F (force), Group F(LLLT) (force and LLLT), Group F+R (force and retention) and Group F+R(LLLT) (force, retention and LLLT). The root resorption volume of the distal buccal root and mesial root in the maxillary left first molar was calculated by micro-CT, and the DSPP expression level on the compression side of the periodontal ligament was analysed by immunohistochemical staining.

Results: The resorption volume in Group F was greater than that in Group F(LLLT). For the mesial root, the volume in Group F was greater than that in Groups F+R and F+R(LLLT). For the distal buccal root, the volume in Groups F and F+R was greater than that in Group F+R(LLLT). The DSPP level in Group F(LLLT) was greater than that in Group F and there was no difference between Groups F+R and F+R(LLLT).

Conclusions: LLLT has a certain preventive effect and a limited reparative effect on OIIRR in rats.

Objective: The effects of unilateral increased occlusal vertical dimension (iOVD) on bilateral craniofacial, mandibular and alveolar development in growing rats were investigated via cone-beam computed tomography (CBCT). The role of Wnt/β-catenin signalling in this process was examined.

Materials and methods: Forty-eight female Sprague-Dawley rats were randomly allocated into unilateral iOVD and sham groups. At 2, 4 and 8 weeks, the rats were scanned via CBCT to analyse cranial, maxillary, mandibular and dental morphology. Changes in temporomandibular joint (TMJ) cartilage histology and Wnt/β-catenin signalling were assessed by histochemical and immunohistochemical staining and qRT-PCR.

Results: Dorsal cephalograms revealed that the mandible in the iOVD group tilted approximately 4° to the right. Unilateral iOVD had little effect on cranial and maxillary growth but inhibited mandibular growth (mandibular length and ramal height), especially on the deviated side (DS). Moreover, unilateral iOVD increased the length of the lower incisors and decreased the height of the molars on the DS. Unilateral iOVD induced bilateral osteoarthritis-like changes in the bilateral TMJ condylar cartilage and activated Wnt/β-catenin signalling in the condylar cartilage, especially on the contralateral side (CLS).

Conclusion: Occlusion with unilateral iOVD induced mandibular deviation, significantly inhibited mandibular growth and produced compensatory changes in the alveolar bone. In the iOVD group, the mandibular body length and ramal height were greater on the CLS than on the DS. Moreover, the greater β-catenin protein expression in the TMJ condylar cartilage on the CLS than on the DS may account for the difference in asymmetrical mandibular development.

Objectives: To evaluate the performance of smartphone scanning applications (apps) in acquiring 3D meshes of cleft palate models. Secondarily, to validate a machine learning (ML) tool for computing automated presurgical plate (PSP).

Materials and methods: We conducted a comparative analysis of two apps on 15 cleft palate models: five unilateral cleft lip and palate (UCLP), five bilateral cleft lip and palate (BCLP) and five isolated cleft palate (ICP). The scans were performed with and without a mirror to simulate intraoral acquisition. The 3D reconstructions were compared to control reconstructions acquired using a professional intraoral scanner using open-source software.

Results: Thirty 3D scans were acquired by each app, totalling 60 scans. The main findings were in the UCLP sample, where the KIRI scans without a mirror (0.22 ± 0.03 mm) had a good performance with a deviation from the ground truth comparable to the control group (0.14 ± 0.13 mm) (p = .653). Scaniverse scans with a mirror showed the lowest accuracy of all the samples. The ML tool was able to predict the landmarks and automatically generate the plates, except in ICP models. KIRI scans' plates showed better performance with (0.22 ± 0.06 mm) and without mirror (0.18 ± 0.05 mm), being comparable with controls (0.16 ± 0.08 mm) (p = .954 and p = .439, respectively).

Conclusions: KIRI Engine performed better in scanning UCLP models without a mirror. The ML tool showed a high capability for morphology recognition and automated PSP generation.

Objectives: Rapid maxillary expansion (RME) is a widely used technique to treat maxillary transverse deficiency. Piezo1 is a cation channel that is activated by mechanical force and regulates bone formation. This study aims to elucidate the role of Piezo1 in bone remodelling during the RME process.

Materials and methods: In this study, the periosteal-derived stem cells (PDSCs) were cultured and stretched by the Flexcell system. The effects of Piezo1 on osteogenesis were assessed via RNA sequencing, real-time quantitative PCR, and western blot analyses. Moreover, for in vivo analyses, the rat RME model was established. The function of Piezo1 in mid-palatal suture bone remodelling was evaluated using micro-CT, haematoxylin-eosin (HE) staining, and immunohistochemistry analyses.

Results: It was revealed that under tension force, the osteogenic factors (Runt-related transcription factor 2, Osterix, and Alkaline Phosphatase) and Ca²⁺/calmodulin -dependent protein kinase (CaMKII) were significantly enhanced in PDSCs over time. Furthermore, these were also upregulated in the RME model with the expansion of the mid-palatal suture. However, Piezo1 inhibition by Grammostola spatulata mechanotoxin 4 downregulated the levels of these factors in the RME model.

Conclusions: This study indicated that Piezo1 is associated with the osteogenesis of PDSCs and bone remodelling in the RME process. CaMKII might also participate in this process.