Marco Migliorati, Sara Drago, Tommaso Castroflorio, Paolo Pesce, Giovanni Battista, Alessandra Campobasso, Giorgio Gastaldi, Filippo Forin Valvecchi, Anna De Mari. Korean J Orthod 2024;54:160-70. https://doi.org/10.4041/kjod23.268

Background. Orthodontic appliances induce significant changes in the oral microbiome, but this shift in microbial composition has not been well established by the available evidence yet. Objectives. To perform a systematic review of existing literature in order to assess the taxonomic microbial changes in orthodontic patients during Fixed Appliance Treatment (FAT) and Clear Aligner Treatment (CAT), using next-generation sequencing (NGS) technique of the bacterial 16S rRNA gene. Search Methods and Selection Criteria. The search for articles was carried out in PubMed, including articles published in English until May 2021. They included every human study report potentially relevant to the review. Data Collection and Analysis. After duplicate study selection and data extraction procedures according to the PICOS scheme, the methodological quality of the included papers was assessed by the Swedish Council on Technology Assessment in Health Care Criteria for Grading Assessed Studies (SBU) method. Results. The initial search identified 393 articles, 74 of which were selected by title and After full-text reading, six articles were selected according to inclusion criteria. The evidence quality for all the studies was moderate. Conclusions. Orthodontic treatment seems to transiently affect the composition of subgingival microbiome, although not salivary, maintaining a stable microbial diversity. Different results were found in the shift of microbiome between plaque and saliva, depending on the type of orthodontic treatment. This review should be interpreted with some caution because of the number, quality, and heterogeneity of the included studies.

Objective: To evaluate the accuracy of dental rotational movements using clear aligners with different attachment configurations.Materials and Methods: This retrospective study analysed 212 teeth from 89 patients undergoing Invisalign treatment. Digital models were analysed after the virtual treatment plan (ST1) and after the first treatment phase (ET1) to evaluate the effective clinical rotational movement. The rotational movements of incisors, canines, and bicuspids were measured using data from the Clincheck Movements Table. ST1 and ET1 were compared to determine the actual rotational movement achieved (ST1‐ET1). The presence or absence of attachments (rectangular or optimized) on teeth was analysed. The accuracy of rotational movements among attachment types was compared using the Kruskal‐Wallis test. Multiple linear regressions were conducted with accuracy as the dependent variable and tooth type, gender, and age as predictors.Results: Optimized attachments had the highest median accuracy (70%), followed by rectangular (65%), and without attachment (63%), with no significant differences (p = .5). There were no significant differences across age groups, genders, or tooth types. Baseline accuracy was 68.62% (95% CI: 56.03–81.20, p < .001). Age was a significant predictor (estimate = −0.30, 95% CI: −0.58 – −0.03, p = .032), indicating decreased accuracy with increasing age. The model's R² was 0.046, with an adjusted R² of 0.003, indicating minimal variance explained.Conclusion: The addition of attachment configurations to clear aligners improves rotational accuracy, but not significantly. Further advancements in these configurations are needed to enhance the performance of the aligners.

This paper evaluated the accuracy of a computer-aided design and manufacturing indirect bonding technique using a new customized 3D-printed transfer tray and a flash-free adhesive system for orthodontic bonding. This in vivo study analyzed 106 teeth selected from 9 patients undergoing orthodontic treatment. Quantitative deviation analysis was performed to evaluate the bonding positioning errors, assessing the differences between the virtually planned and the clinically transferred bracket position after indirect bonding procedures by superimposing 3-dimensional dental scans. Estimated marginal means were evaluated for individual brackets and tubes, arch sectors, and overall collected measurements. A total of 86 brackets and 20 buccal tubes were analyzed. Among individual teeth, mandibular second molars showed the highest positioning errors, whereas maxillary incisors reported the lowest values. Considering arch sectors, the posterior areas showed greater displacements than the anterior areas, as the right side compared to the left side, with a higher error rate reported for the mandibular arch than the maxillary arch. The overall bonding inaccuracy measurement was 0.35 mm, below the clinical acceptability limit of 0.50 mm. The accuracy of a 3-dimensional-printed customized transfer tray using a flash-free adhesive system in computer-aided design and manufacturing indirect bonding was generally high, with greater positioning errors for posterior teeth.

Aim: The authors provided an accurate, simple, and noninvasive method for matching the intraoral scan with facial scan of a patient, without the need of a cone beam computed tomography (CBCT). Materials and methods: Three different facial scans were acquired: the first one with the mouth closed, the second one with a voluntary “social smile”, and the last one scanned the face with a lip-and-cheek retractor with dental arches in occlusion. The base of this method is to superimpose the area of the dental arches acquired by a face scanner with the same area derived by an intraoral scanner. Result: An accurate matching of intraoral and facial scans can be achieved without the risks of radiation exposure. Conclusions: The virtual patient helps the orthodontist to improve both diagnosis and treatment planning: a three-dimensional digital smile design can be performed, the patient’s smile can then be analyzed in the context of the lips, and the teeth can be moved to achieve a consonant and balanced smile. All this information can be integrated in a clear aligner therapy or an indirect bonding procedure, enhancing outcomes in the facial esthetics.

This scientific article investigates the mechanical properties of a novel three-dimensional-printing resin specifically designed for orthodontic aligners and compares it to other commonly used resins. The resin was made by blending two commercially available and certified resins to produce aligners with improved mechanical properties compared to each separate resin. The study examined the effect of the addition of NextDent Ortho Rigid resin on the mechanical properties of the specimens, more specifically analyzing the relationship between the amount of the added rigid resin and the mechanical properties of the specimens. The mechanical properties of the specimens and the nickel-titanium wires were analyzed using a three-point bending test setup. The results showed no statistically significant differences within the different groups of specimens. The study provides valuable insights into the potential of the resin to meet the mechanical demands of orthodontic treatments. It will contribute to the advancement of personalized orthodontic care through three-dimensional-printing technology. Blending commercially available and certified resins enables orthodontic practitioners to select the most suitable resin for each case, providing better outcomes for patients and increasing the efficiency of the treatment process. Further research and evaluation would be required to determine the suitability of the blended resin for orthodontic treatments.