The aim of this work was to evaluate the efficacy and accuracy of maxillary arch transverse expansion using the Invisalign^® clear aligner system without auxiliaries other than Invisalign attachments. Knowing the accuracy of a movement through a clear aligner system allows the clinician to plan the treatment with greater precision and to achieve the expected result faster. The study group included 28 patients with a mean age of 17 ± 3.2 years. The treatment protocol for all the selected patients included the application of the Invisalign^® clear aligner system without auxiliaries, except for the Invisalign^® attachments; in no case were tooth extraction or interproximal enamel reduction (IPR) performed. Linear measurements of the expansion were assessed before treatment (T0), at the end of treatment (T1), and on final virtual models by ClinCheck^® (TC). A paired t-test was used to compare T0-T1 and T1-TC differences. A paired t-test was applied, and one normality was validated with the Shapiro–Wilks test. If normality was not met, the nonparametric test (Mann–Whitney U test) was applied. The level of significance was set at 5%. Statistically significant differences were found for all measurements at T0-T1. The results showed an average accuracy of efficacy of 70.88%. The differences in predictability between the various vestibular measurements (intercanine, inter-premolar, and intermolar) were not statistically significant, while they were for gingival measurements. The overall accuracy of the expansion treatment was 70%, regardless of tooth type.

This systematic review aims to further current knowledge on the effects of microplastics from orthodontic clear aligners, identifying potential implications for human health and providing a basis for further research and development of alternative materials. A literature search to find all peer-reviewed citations relevant to the review topic was conducted in the following databases: PubMed, Scopus, Web of Science, and Cochrane Library on 31 December 2024. A manual search of grey literature was also performed. There were 62 citations retrieved by the search query, and 11 were selected for inclusion in the review. Four selected studies were in vitro, while seven were in vitro following intraoral material aging studies. Ten studies evaluated the surface morphology of the material after aging, among the mechanical characteristics assessed, while only one article evaluated the chemical characteristics and size of the microplastic particles released from the aligners after simulated in vitro use. Discussion: From the evaluation of the studies included in this review, it is possible to state that there is a gradual increase over time in the surface roughness of the material, and modifications occurred in the morphology and surface topography of the aligners. Furthermore, it emerged that dispersion of microplastics occurs during the use of different types of aligners, with microplastic particle sizes ranging from 5 to 20 μm The findings suggest that clear aligners may cause microplastic dispersion in saliva during therapy, and this could cause a problem for the general health of patients, due to the absorption or ingestion of these released molecules. Further research is needed to fully understand the extent of microplastics released from aligners and to find alternative materials that can reduce this occurrence.

Background: The aim of this RCT is to show the effectiveness of laser technology for the exposure of palatally impacted canines, using a CO₂ or diode laser, and to evaluate the possible bio-stimulation effect of the laser on the spontaneous eruption of the canine. Methods: This study was carried out on a sample of 27 patients, divided randomly into three groups: treated with a CO₂ laser (Group A), treated with a diode laser (Group B), and treated with a cold blade (Group C). Monitoring was performed at 1, 8, and 16 weeks after surgery, through photo and digital scans performed with a CS3500 intraoral scanner. Results: It was found that the average total eruptions are 4.55 mm for Group A, 5.36 mm for Group B, and 3.01 mm for Group C. The difference in eruption between groups A and B is not significant. Comparing the laser groups with the control group, it has emerged that the difference in eruption is statistically significant. Conclusion: A significant tooth movement was observed in both Groups A and B. The response of the canine to the bio-stimulation of the laser can be considered effective, resulting in a statistically significant difference between the study groups and the control group. Both lasers have the same bio-stimulatory action on the eruption of canines.

Background: This study aimed to investigate the association between the internal derangement of the temporomandibular joint (TMJ), in particular the severity of disc displacement (DD), and the presence of generalized joint hypermobility (GJH) in growing patients evaluated on magnetic resonance images (MRIs). The study also investigated the relationship between the stages of DD severity and age. Methods: This cross-sectional study has been conducted on a pre-orthodontic population (8–16 years). The GJH was assessed with the Beighton test (cutoff ≥ 4) and the final sample of 56 patients was divided into two groups: a study group, 30 subjects with GJH, and a control group, 26 subjects without GJH. The disc position was evaluated on MRI and the severity of DD was classified in four stages. Pearson’s χ2 Test was performed for the analysis of the statistical correlation. Results: A statistically significant relationship between GJH and disc position was found, in particular, a disc displacement with reduction (DDwR) and DD severity. A positive association also emerged between the severity of DD and age, that increased with increasing age. Conclusions: The research results suggest that there is an association between the presence of generalized joint hypermobility (GJH) and disc displacement (DD) in growing patients. Growing patients with GJH showed a higher severity of DD. In older patients, greater severity of DD was evident, suggesting that this condition may worsen with age during growth.

Background: This study aimed to investigate the association between the internal derangement of the temporomandibular joint (TMJ), in particular the severity of disc displacement (DD), and the presence of generalized joint hypermobility (GJH) in growing patients evaluated on magnetic resonance images (MRI). The study also investigated the relationship between the stages of DD severity and age. Methods: This cross-sectional study has been conducted on a pre-orthodontic population (8-16 years). The GJH was assessed with the Beighton test (cutoff ≥ 4) and the final sample of 56 patients was divided into two groups: a Study Group, 30 subjects with GJH, and a Control Group, 26 subjects without GJH. The disc position was evaluated on MRI and the severity of DD was classified in four stages. Pearson's χ2 Test was performed for the analysis of the statistical correlation. Results: A statistically significant relationship between GJH and disc position was found, in particular a disc displacement with reduction (DDwR) and DD severity. It also emerged a positive association between the severity of DD and age, that increased with increasing age. Conclusions: Growing patients with GJH have a higher risk of developing DD and with more severe stages. The risk of developing DD and the severity increases with increasing age.

Unilateral condylar hyperplasia (UCH) is one of the causes of facial asymmetry, and it is characterized by increased growth in one of the mandibular condyles. In UCH, it is important to determine whether the metabolic activity of the hyperplastic condyle is still active. Fractal dimension (FD) analysis could be a non-invasive method to identify active metabolic activity. The aim of this study is to compare the FD of the hyperplastic condyle with the contralateral one in patients with facial asymmetry and positive bone scintigraphy and to compare the FD of the right and left condyles in symmetrical patients. A cross-sectional retrospective study of fifteen patients with facial asymmetry and positive bone scintigraphy and fifteen symmetrical patients was conducted. Clinical data and scintigraphy results were collected from medical records, and CBCT scans were used for the application of FD by pre-processing the images according to White and Rudolph and using ImageJ^® (1.54p) software and the box-counting method. Wilcoxon’s t test was used to analyze the differences in FD between the hyperplastic and contralateral condyles in patients with UCH and between the right and left condyles in symmetrical patients. A p-value of <0.05 was considered statistically significant. The FD of the hyperplastic condyles was significantly higher than the contralateral one in the axial and coronal plane (p = 0.001). The analysis of FD of the mandibular condyle can be a useful non-invasive method to identify active UCH in patients with facial asymmetry.