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Numerous surgical techniques have been developed as effective means to facilitate orthodontic treatment, but they may cause significant postoperative discomfort. Piezocision was established as a flapless and minimally invasive technique to accelerate orthodontic tooth movement by combining small vertical incisions and piezoelectric corticotomies. Computed tomography is combined with the Piezocision technique to fabricate CAD/CAM surgical guides to prevent iatrogenic damage. A method to combine computer-assisted dynamic navigation with Piezocision is introduced here. CBCT was combined with motion-tracking technology to allow real-time tracing of the piezoelectric instruments during the surgical procedure. This technique delivers the location of the piezoelectric knife in regard to roots and important anatomical structures to increase the safety and accuracy during corticotimies. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the clinical effectiveness of regenerative treatment of intrabony defects in combination with consecutive orthodontic therapy with clear aligners in stage IV (type 2) periodontitis. Method and materials: Ten patients with a total of 103 intrabony defects were analyzed after regenerative surgery using collagen-deproteinized bovine bone mineral with or without collagen membrane or enamel matrix derivative followed by orthodontic therapy with clear aligners. Changes in radiographic bone level and probing pocket depths were evaluated after 1 year (T1) and at final splinting (T2) after orthodontic tooth movement. Results: Mean radiographic bone level gain was significant, with 2.13 ± 1.64 mm at T1 and 3.02 ± 2.00 mm at T2. Mean probing pocket depth was significantly reduced from 5.40 ± 1.80 mm at baseline to 3.78 ± 1.73 mm at T1, and remained stable with 3.73 ± 1.70 mm at T2. Pocket closure (≤ 4 mm probing pocket depth) was accomplished in 76% of all defects. Tooth loss amounted to 2.9%. Conclusion: Within the limitations of the retrospective study design, the findings suggest that the interdisciplinary treatment of periodontitis stage IV by regenerative periodontal surgery and consecutive orthodontic therapy with clear aligners can lead to favorable results. [ABSTRACT FROM AUTHOR]

Objective: The evidence base for the use of space maintainers is relatively sparce despite being used for decades after the premature loss of primary molars. This study aims to increase the dental evidence base via investigating retrospectively the success rates of prefabricated fixed and removable space maintainers inserted from 2019 to 2021 and followed up until February 2023 at a specialized university clinic and to identify reasons for any reported minor and major failure. The authors hypothesized that there is no significant difference in failure rates between fixed and removable space maintainers inserted after the premature loss of a single primary molar per quadrant. Method and materials: Patients' digital records were searched yielding 645 space maintainers. After the application of inclusion criteria, 157 (67%) fixed prefabricated space maintainers in 112 children and 77 (33%) removable space maintainers in 61 children were analyzed for an average of 18.4 ± 9.5 months. Results: Kaplan-Meier survival analysis with Mantel-Cox statistics showed an overall cumulative survival time of 31.6 months (SE = 1.15, 95% CI = 29.4 to 33.9). Major failure occurred significantly more in removable maintainers (n = 40/67, 59.7%), mostly due to loss of the appliance, compared to fixed space maintainers (n = 27/67, 40.3%; P < .001). The present study indicates that space maintainers were mainly placed in young children with high caries experience, where treatment was mostly possible using advanced behavior management. Conclusions: Fixed space maintainers had a significantly lower failure rate than their removable counterpart. However, both require continual repairs, preservation, or even replacement till the eruption of the permanent tooth. [ABSTRACT FROM AUTHOR]

This clinical case outlines a comprehensive digital workflow for a minimally invasive multidisciplinary treatment. The process utilizes one open-source software for digital wax-up and one low-cost software to address esthetic concerns related to teeth misalignment. The patient's function was stabilized with a digitally made occlusal splint. The application of the described digital workflow technique, incorporating open-source, lowcost, and closed software, played a pivotal role in attaining a straightforward and predictable outcome with minimally invasive treatment. Furthermore, the continual evolution of technology contributes to the growing precision of dental procedures. The presented digital workflow helped formulate a predictable treatment plan, replicate a diagnostic digital wax-up, and achieve precise teeth alignment. This approach satisfactorily addressed the patient's esthetic concerns, providing an outstanding approximation of the definitive result. [ABSTRACT FROM AUTHOR]

Oral dysesthesia (OD) is a diagnosis of exclusion that manifests as an unpleasant and abnormal sensation of the oral mucosa without any noticeable oral lesions. Burning sensation is one of the manifestations of OD which may advocate for similar pharmacotherapeutic options to burning mouth syndrome (BMS), resulting in possible adverse events. The aim of these case reports was to illustrate the significance and rationale for the use of oral devices as a mechanical/physical barrier and a safe approach in the management of OD, without experiencing any antagonistic effects from pharmacotherapeutic agents. Two patients with spontaneous and evoked (following dental procedures) OD symptoms in the right posterior mandibular quadrant and anterior hard palatal areas were evaluated. Additionally, their OD symptoms were associated with hyposalivation and taste changes. A thorough history and complete head and neck examination, with the exclusion of oral lesions and systemic conditions, were performed. These patients were previously prescribed topical clonazepam rinses. An in-office trial, with application of orthodontic wax to the affected area, was performed as a preliminary test in order to justify the fabrication of an oral device for possible symptomatic relief. Conclusion: The case reports demonstrated significant improvement of OD symptoms and amelioration of pain following fabrication of oral devices in two patients with no undesirable effects from pharmacotherapy. Additionally, the oral devices aided as a mechanical/physical barrier, potentially exerting a placebo effect while facilitating an improved quality of life. Furthermore, the cost-effectiveness and ease of fabricating the oral device has been advantageous over other systemic medications. This encourages the need for a detailed prospective study. [ABSTRACT FROM AUTHOR]

Objective: This study compared the achieved tooth movement to that predicted in the preliminary simulated digital treatment plan between adults and teenagers. Materials and methods: Records of 60 patients (30 adults; mean age: 36.6 ± 11.36 years, and 30 teenagers; mean age: 16.23 ± 2.25 years) were randomly selected. Initial and predicted models were obtained from the initial simulated treatment plan. The first model of the refinement scan was labeled as achieved. SlicerCMF software (version 3.1; https://www.slicer.org) was used to superimpose the achieved and predicted digital models over the initial ones with regional superimposition on relatively stable first molars. 600 teeth were measured in each group for horizontal, vertical, angular movements, and transverse dimensions. Accuracy was defined as the achieved amount of movement minus predicted and was calculated for each individual and compared between teens and adults. Results: The mandibular inter-canine width accuracy was statistically significant between groups (p = 0.050). Significant under-correction in horizontal movements was noted for mandibular first premolars in teenagers compared to adults (p = 0.037). There was considerable over-correction in horizontal movements for mandibular central and lateral incisors between groups (p < 0.05). No significant difference was observed between groups in the vertical plane. Rotations were underachieved for maxillary first premolars, more in adults than teenagers (p = 0.017). Conclusion: The accuracy of achieved versus predicted tooth movement between adults and teenagers was significant for the inter-canine width. Mandibular central and lateral incisors showed significantly greater over-correction in adults in the horizontal plane. The accuracy of rotations and vertical movements was comparable. [ABSTRACT FROM AUTHOR]

The aim of this systematic review was to assess the antimicrobial effectiveness of silver nanoparticles (AgNPs) incorporated to different orthodontic bonding systems. Additionally, the review investigated the impact of AgNPs on the bonding properties of these materials. The hypothesis posed that the addition of AgNPs would enhance the antimicrobial efficacy of orthodontic bonding systems while maintaining their bonding properties. The systematic review employed a PICO-based search strategy, targeting in vitro studies focusing on the integration of nano silver particles into orthodontic bonding systems with potential antimicrobial activity. The intervention involved the use of nano silver in orthodontic bonding systems, with a comparison to systems lacking nano silver. The primary outcomes assessed were antimicrobial activity and shear bond strength (SBS). The search process, conducted without publication date restrictions, yielded 551 potential articles: 34 from PubMed, 360 from PubMed Central, 42 from Embase, 54 from Scopus, and 61 from Web of Science. Ultimately, a qualitative synthesis was conducted on 13 papers. The PRISMA diagram, visually represented the search strategy, screening process, and inclusion criteria. The study protocol was registered in PROSPERO CRD42023487656 to enhance transparency and adherence to systematic review guidelines. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale, revealing that the 13 articles meeting the inclusion criteria demonstrated a high level of evidence. Seven studies were included in the meta-analysis regarding shear bond strength. In summary, the synthesized findings from these studies strongly underscore the promising potential of orthodontic materials modified with AgNPs. These materials exhibit effective resistance against cariogenic bacteria without compromising bonding properties below clinical acceptability. Such innovative materials hold significant implications for advancing oral health within the realm of orthodontics. [ABSTRACT FROM AUTHOR]

Background: Fixed orthodontic appliances act as a niche for microbial growth and colonization. Coating orthodontic wires with antimicrobial silver nanoparticles (AgNPs) and nanocomposite was adopted in this study to augment the biological activity of these wires by increasing their antibacterial and antibiofilm properties and inhibiting bacterial infections that cause white spot lesions and lead to periodontal disease. Methods: Three concentrations of biologically synthesized AgNPs were used for coating NiTi wires. The shape, size, and charge of the AgNPs were determined. Six groups of 0.016 × 0.022-inch NiTi orthodontic wires, each with six wires, were used; and coated with AgNPs and nanocomposites. The antimicrobial and antibiofilm activities of these coated wires were tested against normal flora and multidrug-resistant bacteria (Gram-positive and Gram-negative bacterial isolates). The surface topography, roughness, elemental percentile, and ion release were characterized. Results: AgNPs and nanocomposite coated NiTi wires showed significant antimicrobial and antibiofilm activities. The chitosan-silver nanocomposite (CS-Ag) coated wires had the greatest bacterial growth inhibition against both Gram-positive and Gram-negative bacteria. The surface roughness of the coated wires was significantly reduced, impacting the surface topography and with recorded low Ni and Ag ion release rates. Conclusions: NiTi orthodontic wires coated with AgNPs, and nanocomposites have shown increased antimicrobial and antibiofilm activities, with decreased surface roughness, friction resistance and limited- metal ion release. [ABSTRACT FROM AUTHOR]

Background: Clear thermoplastic materials are used in a variety of oral appliances. In some situations, patients may wear clear thermoplastic appliances while eating. However, the effect of wearing clear thermoplastic appliances on chewing efficiency is unknown. This study aimed to evaluate the differences in masticatory function between chewing with and without wearing clear thermoplastic retainers over a 6-month period, and its associated factors. Methods: Thirty patients who received upper and lower clear retainers after debonding fixed appliances were examined for objective and subjective masticatory function at retainer delivery (T0), 3-month (T1), and 6-month follow-ups (T2) in two conditions: with and without wearing their retainers while chewing. The objective method used multiple sieves reported as the median particle size (MPS). The food intake ability (FIA) test served as the subjective method. Paired t-test was used to compare the outcomes between chewing with and without retainers at each evaluation time point. Repeated measures ANOVA followed by the Bonferroni post-hoc test was used to compare the outcomes between the three evaluating time points. Multivariable linear regression analysis was performed to assess whether age, sex, and extraction/non-extraction was associated with these effects. Results: The MPS was significantly greater when chewing with retainers compared with chewing without them at T0 (P < 0.05), however, it was not significantly greater at T1 and T2 (P > 0.05). The MPS with and without the retainers tend to decrease between T0, T1 and T2. In particular, the MPS while chewing with retainers significantly decreased between T0 and T1. The total FIA score and FIA subscores for hard and soft food were significantly lower when eating with retainers at T0 (P < 0.05), however, all FIA scores when eating without retainers did not significantly change between T0, T1, and T2. No significantly associated factors were identified. Conclusions: Wearing clear retainers while chewing decreases objective and subjective masticatory function immediately after completing orthodontic treatment. However, this significantly improved to levels comparable to chewing without retainers after a 3-month follow-up. Age, sex, and extraction/non-extraction treatment were not associated with the difference in masticatory function while chewing with and without wearing the retainers. [ABSTRACT FROM AUTHOR]

Introduction: Deep bite, a common orthodontic malocclusion, necessitates timely intervention to prevent potential side-effects. If left untreated, a deep bite can lead to increased tooth wear, dental injuries, and Temporomandibular Joint (TMJ) disorders. Various treatment modalities, such as anterior teeth intrusion and posterior teeth extrusion, are employed to correct deep bite. However, selecting the optimal approach requires careful consideration of patient-specific factors and treatment objectives. While anterior teeth intrusion is effective for mild to moderate cases, posterior teeth extrusion may be preferred in severe deep bite scenarios. There are various treatment modalities for deep bite correction such as intrusion arches and mini screw implants. Jayade's intrusion arch, detailed by A.V. Jayade in "Refined Begg for Modern Times" (2001), is an orthodontic appliance designed to correct vertical dental misalignments by intruding over-erupted anterior teeth. The modified three-piece intrusion arch is an advancement of the traditional intrusion arch technique. It incorporates three distinct segments: two lateral segments and a central segment. This design allows for greater precision and control over the intrusion forces applied to specific teeth or groups of teeth. Need of the Study: Simultaneous intrusion and retraction mechanics in orthodontic treatment are very challenging, and there is a paucity of data regarding the best modalities for achieving these with minimal root resorption. Introduction: Deep bite, a common orthodontic malocclusion, necessitates timely intervention to prevent potential side-effects. If left untreated, a deep bite can lead to increased tooth wear, dental injuries, and Temporomandibular Joint (TMJ) disorders. Various treatment modalities, such as anterior teeth intrusion and posterior teeth extrusion, are employed to correct deep bite. However, selecting the optimal approach requires careful consideration of patient-specific factors and treatment objectives. While anterior teeth intrusion is effective for mild to moderate cases, posterior teeth extrusion may be preferred in severe deep bite scenarios. There are various treatment modalities for deep bite correction such as intrusion arches and mini screw implants. Jayade's intrusion arch, detailed by A.V. Jayade in "Refined Begg for Modern Times" (2001), is an orthodontic appliance designed to correct vertical dental misalignments by intruding over-erupted anterior teeth. The modified three-piece intrusion arch is an advancement of the traditional intrusion arch technique. It incorporates three distinct segments: two lateral segments and a central segment. This design allows for greater precision and control over the intrusion forces applied to specific teeth or groups of teeth. Need of the Study: Simultaneous intrusion and retraction mechanics in orthodontic treatment are very challenging, and there is a paucity of data regarding the best modalities for achieving these with minimal root resorption. [ABSTRACT FROM AUTHOR]

Background: This study evaluated the number of aligners that Invisalign ClinCheck™ Pro Software estimates for correcting different malocclusion traits. Methods: This retrospective study included 157 non-extraction patients over the age of 12 years old with easy to mild malocclusions who were treated with Invisalign aligners. The Index of Complexity, Outcome, and Need (ICON) was used to evaluate the malocclusion complexity level. The number of aligners (upper, lower, and total) required to correct the malocclusion was compared based on sex, ICON level, molar and canine class, occlusal asymmetry, overbite, overjet, crowding, incisor inclination, and Bolton discrepancy. A Mann–Whitney U test (for comparisons between two groups) or a Kruskal–Wallis test (for comparisons between three or more groups) (p < 0.05) was used to evaluate differences in the number of aligners across variable categories. Results: ICON, molar class, overbite, and overjet presented significant differences (p < 0.05) in the number of aligners (upper, lower, and total) required to correct a malocclusion. Canine class and lower dental crowding showed significant differences in the lower and total number of aligners (p < 0.05). Conclusions: The number of aligners increases when the malocclusion presents any of the following elements: the absence of molar or canine class I, an altered overjet or overbite, severe lower crowding, or a higher complexity level. The clinician should consider these malocclusion traits when estimating the number of aligners needed for correction. [ABSTRACT FROM AUTHOR]

Background/Objectives: The orthodontic treatment of posterior crossbite using appliances for gradual maxillary expansion is crucial to ensure proper transversal jaw relationships as much as occlusal functionality. The aim of this study was to analyze forces and torques generated by different appliances for maxillary expansion. Methods: Measurements were conducted for the Wilson® 3D® Quadhelix (WQH) and Wilson® 3D® Multi-Action Palatal Appliance (WPA) across various sizes and compared to the Remanium® Quadhelix (RQH). Activations were set to 8 mm for the WQH and RQH and 6 and 8 mm for the WPA. Rotations and root torque were simulated via an activation of 10° for arches. A total of eight test series were conducted. Results: The WPA displayed the highest force and torque values for all movements, far surpassing recommended guideline values (expansion 8.5–>15.0 N/46.3–86.5 Nmm, rotation 3.1–6.1 N/40.7–61.4 Nmm, torque 3.9–5.1 N/22.4–29.7 Nmm), and the WQH displayed the lowest values (expansion 2.7–12.6 N/11.1–39.6 Nmm, rotation 0.1–1.7 N/23.0–32.2 Nmm, torque 0.9–2.9 N/3.4–10.5 Nmm). Appliances with the smallest transverse dimensions exhibited the highest force and torque maxima. Conclusions: This study underscores the importance of understanding biomechanical principles in orthodontics for minimizing unintended tooth movements, providing detailed insights into the force systems of appliances acting in the transverse plane, and establishing a foundation for future clinical investigations to validate these in vitro findings. [ABSTRACT FROM AUTHOR]

Background: Differences in the effects of cream‐type denture adhesives and home liners remain unclear. Objective: This cross‐sectional study aimed to clarify the differences in the oral‐hygiene status and masticatory performance between participants using cream‐type denture adhesives and those using home liners. Methods: Masticatory performance with and without cream‐type denture adhesives and home liners was evaluated using colour‐changeable chewing gum. Oral hygiene was assessed using the tongue coating index (TCI). Propensity‐score matching was performed using oral moisture, presence of palatal or mandibular protuberances, type of residual ridge, denture type (complete or partial denture), and denture retention as background factors. Wilcoxon signed‐rank test was used to examine the differences in masticatory performance with and without cream‐type denture adhesives and home liners and differences in masticatory performance and TCI between the cream‐type denture adhesive and home‐liner groups. Results: This study included 38 and 40 cream‐type adhesive and home‐liner users, respectively, and 17 pairs were obtained after propensity‐score matching. The Wilcoxon signed‐rank tests showed that masticatory performance was significantly different with and without the use of home liners, and higher values were obtained with the use of home‐liners. However, the cream‐type denture adhesive and home‐liner groups showed no significant differences in terms of the change in masticatory performance with the use of them. Furthermore, Wilcoxon signed‐rank tests showed that TCI values were significantly high in the cream‐type adhesive group. Conclusion: The findings in this study suggest that home liners improve masticatory performance and that participants regularly using cream‐type denture adhesives have poorer oral hygiene. [ABSTRACT FROM AUTHOR]

Objective: Less than ideal contacts have been reported following aligner therapy, but it is considered a transitory problem, spontaneously resolving with the phenomenon of settling. Methods: Thirty-nine orthodontic patients (14 treated with aligners; 25 with fixed appliances) were evaluated with a digital occlusal analysis system (T-scan™10), assessing Maximum Intercuspation contact simultaneity, symmetry, and relative force distribution at treatment completion and after 3 and 6 months. Results: No significant differences in occlusal contact quality were found between groups at treatment completion or follow-up. The center of force moved posteriorly and remained stable after 3 months but was located more anteriorly in females (p = 0.01). One-third of patients (both groups combined) had marked contact force asymmetry even after 6 months' retention. Conclusion: Occlusal contacts were comparable at completion of treatment with aligners or brackets and after 3–6 months of retention. Settling did not improve marked asymmetry in all patients. [ABSTRACT FROM AUTHOR]

Objective: To assess the impact of treatment with orthodontic aligners (OA) on oral health‐related quality of life (OHRQoL) in patients with trisomy 21 (T21) compared to non‐syndromic patients. Materials and methods: The sample consisted of 30 patients, both sexes, aged between 11 and 35 years, divided into two groups: T21 (n = 10, patients with T21, treated prospectively) and CONTROL (n = 20, control group, non‐syndromic patients, from the Orthodontic Laboratory of UNOPAR). In both groups, patients were treated with Invisalign orthodontic aligners (Align Technology), following the same treatment parameters. Participants, assisted by their caregivers, when necessary, answered Oral Health Impact Profile (OHIP‐14) instrument and the patient's guardians answered the Oral Health Scale for People with Down's syndrome (OHDS) instrument, before (T0) and after 30 (T1), 180 (T2), and 365 (T3) days from the start of treatment. Friedman tests with Bonferroni correction and Mann–Whitney tests were used (p <.05). Results: For the OHDS instrument, it was observed that for the eating and communication domains and an overall score, the treatment with OA positively impacted the lives of T21 patients (p <.05). Regarding the OHIP‐14 instrument, the intragroup evaluation showed that in the CONTROL group, there was no significant difference between the evaluated times; while for the T21 group, there was a significant positive impact (p <.05). Conclusion: The results showed that the treatment with aligners positively impacted the OHRQoL of T21 patients, and these results were perceived by caregivers, mainly in relation to issues related to eating and communication. [ABSTRACT FROM AUTHOR]

Periodontal patients may face orthodontic problems because of bone support loss, such as maxillary incisor proclination, spacing, rotation, extrusion, pathologic tooth migration (PTM) or traumatic occlusion. Orthodontic treatment is therefore an element within the comprehensive treatment of periodontitis after the periodontal condition has stabilized. The presence of fixed appliances (FAs) promotes the accumulation of bacterial biofilm and impedes hygiene procedures. The increasing popularity of clear aligner (CA) treatment is due to the convenience of use, less discomfort, better esthetics, easier hygiene, lower failure rate, and shorter, less frequent visits. Therefore, the question arises whether treatment with aligners is a good solution for periodontal patients. To answer this question, the PubMed/Medline, Cochrane Library and EMBASE databases were searched using the following keywords: periodontitis, orthodontic treatment, clear aligners, multibracket orthodontic appliances, fixed appliance, root resorption, gingival recession and pathologic tooth migration. The search strategy identified 18 relevant studies. A total of 1090 participants took part in the analyzed studies. The available literature was analyzed in terms of the occurrence of root apex resorption, the possibility of treating pathologic tooth migration, the occurrence of gingival recession, periodontal health status and occlusal stability in patients treated with CAs and FAs. Despite statistically significant differences in terms of Plaque Index (PI), probing depth (PD), apical root resorption and gingival recession favor the use of CAs. However, these values are mostly of no clinical significance. It is possible to treat PTM with CAs, but it is limited by the high degree of tooth mobility and incisor inclination. Obtaining perfect occlusion is comparably difficult in both CA and FA treatment. When planning orthodontic treatment in patients with reduced periodontium, the use of both CAs and FAs should be considered. The choice of method would ultimately depend on the patient's dental condition. [ABSTRACT FROM AUTHOR]

The aim of this study is to retrospectively investigate the predictability of maxillary arch expansion with Invisalign ® First in mixed dentition. In a sample of 64 treated patients, 3D digital models from the ClinCheck® software were compared with post-treatment digital models. Predicted maxillary expansion was related to the final outcome of expansion. At the cuspidal level, there was observed a predictability of 59.68% for deciduous canines, 63.77% for first deciduous molars, 66.99% for second deciduous molars, and 55.61% for first permanent molars. At the gingival level, there was observed a predictability of 49.87% for deciduous canines, 53.11% for first deciduous molars, 53.36% for second deciduous molars, and 45.16% for first permanent molars. The difference between the predicted and achieved expansion was statistically significant (p < 0.05). Within the present limitations, our results suggest that, with Invisalign® First, it is possible to expand the upper arch in mixed dentition in an effective and predictable way. Clear aligners could represent a new and valid alternative for arch expansion in growing patients. [ABSTRACT FROM AUTHOR]

The article describes the case of a ten-year-old boy who sought orthodontic treatment after dental trauma three years ago, which led to the avulsion of the upper right central incisor. Topics include factors to which the decision to open or close a space is attributed, orthodontic treatment, and restorative treatment.

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The palatal anchorage device (PAD) is commonly used in fixed appliance for anchorage, but the biomechanics of PAD in patients treated with clear aligners(CAs)remains poorly understood, especially in its elastic mode and force magnitude. This study aimed to assess the biomechanical effects of using PAD for retraction during clear aligner treatment (CAT) with the extraction of two maxillary first premolars. Four finite element models were created: (1) Incisors retraction (IR) with active contraction of the clear aligner only; (2) IR with PAD using different forces (50,75,100 g) or not; (3) PAD without IR (forces of 50,75,100 g), and (4) Different elastic directions (D1, D2, D3) from aligner to PAD without IR. IR caused lingual tipping and extrusion of the central incisors, as well as mesial and buccal tipping of the first molar. PAD during IR provided strong anchorage for the first molar, with elastics slightly increasing the lingual tipping and extrusion of the central incisors. Elastics applied to the U-shaped arch led to central incisor intrusion and reduced lingual retraction. The highest stress was observed on the mesial attachment of the canine. PAD effectively reinforced posterior anchorage in CAT, while anterior positioning facilitated anterior teeth intrusion. The biomechanical importance of the canine's mesial attachments in maxillary teeth treatment planning was highlighted. [ABSTRACT FROM AUTHOR]

Background: The purpose of the study was to measure the degree of conversion (DC) of direct-printed aligners (DPA) that were post-cured under ambient and nitrogen atmosphere at specific time intervals and investigate the kinetics of polymerization reaction of this material. Methods: A total of 48 aligners were produced in 4 printing series by a 3D printer with TC-85DAC resin (Graphy Inc). From each series of printing, 12 aligners were included. The aligners were divided into two groups according to their post-curing conditions. One group was post-cured under ambient air with the presence of oxygen and the other under a nitrogen atmosphere, both using the same UV post-curing unit recommended by the company. The aligners were post-cured at six different time intervals: 1, 2, 3, 5, 10, and 20 min. Each time interval included 8 aligners, with 2 aligners from each series. The DC of the cured aligners was measured by means of attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) through acquisition of the respective spectra for each UV-curing condition. Statistical analysis was performed to compare the results and differences within each atmosphere post-curing protocol, as well as between the different selected atmosphere conditions. Statistical significance level was set at p-value ≤ 0.05. Results: Pairwise analysis between post-curing protocols showed statistically significant differences only at the first minute of polymerization. Post-curing with nitrogen did not yield statistically significant results across different time intervals. Post-curing in ambient air showed some significant differences on the 1st and 2nd minute of the post-curing process. Conclusions: Almost complete double bond conversion was observed. Significant differences were observed only during the first minute of polymerization under the nitrogen atmosphere. [ABSTRACT FROM AUTHOR]

Objectives: The Functional Clear Aligner (FCA) is a novel orthodontic appliance designed for the treatment of Class II malocclusion with mandibular retrognathia in adolescents. The aim of this study was to investigate the biomechanical characteristics of the masticatory muscles, jawbone, and temporomandibular joint (TMJ) during mandibular advancement using either FCA or Class II elastics combined with clear aligner (Class II elastics) through finite element analysis. Materials and methods: A 3D finite element model of the 'muscle-jawbone-TMJ-appliance' system was constructed based on CBCT and MRI images of a boy with skeletal Class II malocclusion. Masticatory muscles included masseter, temporal, medial pterygoid, and lateral pterygoid muscles. The TMJ consists of the temporal bone's glenoid fossa, disc, and mandibular condyle. To observe the biomechanical characteristics of the muscles and TMJ during orthodontic appliance wearing and the retention phase, two different protocols were used: Model 1: The mandibular advancement using FCA; Model 2: The mandibular advancement using Class II elastics. Results: The FCA group produced greater and more coordinated masticatory muscle forces compared to the Class II elastics group. Temporal and masseter muscles exhibited the most pronounced variation in muscle strength during mandibular advancement. The FCA group exhibited greater TMJ region stress compared to the Class II elastics group. Interestingly, the stress on the articular discs in both models decreased over time. Tensile stresses were observed in both the condyle and the posterior region of the articular fossa. Conclusion: During skeletal Class II malocclusion treatment, masticatory muscle forces and stress on the TMJ were higher in the FCA group compared to the Class II elastics group. In both models, stress cushioning was provided by the articular disc. [ABSTRACT FROM AUTHOR]

Background: The current review aims to explore the evidence regarding the effectiveness of mandibular advancement orthodontic appliances with maxillary expansion device in treating pediatric Obstructive Sleep Apnea (OSA). Materials and methods: A systematic literature search was conducted across PubMed, Cochrane Central, Web of Science, Embase, Scopus databases, Chinese Biomedical Database, Chinese National Knowledge Infrastructure, and Wanfang. The research involved children and adolescents (under 16 years old) who received mandibular advancement and maxillary expansion functional orthopedic appliances for OSA treatment. We performed narrative reviews and subsequently amalgamated the findings from the studies. Results: Six articles were included for review. Although a small number of studies were included, the research suggested the potential advantages of mandibular advancement for children with OSA. Following treatment, there was a decrease in AHI/RDI, an improvement in sleep quality, and the increase in oxygen saturation. Conclusions: The limited quantity and quality of existing studies necessitate caution when drawing conclusions about the effectiveness of mandibular advancement and maxillary expansion for OSA. In the future, larger and well-designed randomized controlled trials (RCTs) are needed to provide more robust evidence. Patients should be carefully selected, and their orthodontic indications should be thoroughly evaluated before inclusion in such trials.We encourage researchers to design studies that monitor patients over several years to provide a comprehensive understanding of the long-term effectiveness. Trial registration: This study was registered in PROSPERO(CRD42023480407) on November 20, 2023. [ABSTRACT FROM AUTHOR]

Background: The aim of the study is to evaluate the effectiveness of different toothbrushes in reducing gingival inflammation and dental biofilm removal in gingivitis patients with fixed orthodontic appliances. Methods: Following baseline clinical assessments, including the Turesky modification of the Quigley-Hein plaque index (TQHI), gingival index (GI), bleeding on probing (BOP), and probing pocket depth (PPD), all patients received nonsurgical periodontal therapy. Patients were then randomly assigned to one of three groups: conventional toothbrush (C-TB), orthodontic toothbrush (O-TB), or single-tufted toothbrush (ST-TB). Each group received tailored oral hygiene instructions based on their assigned toothbrush type. Clinical assessments were repeated and recorded in the first week, sixth week, and third month. Results: Thirty-six patients with a mean age of 23.14 ± 3.86 (18–32 years) participated in the study. All groups with twelve patients each demonstrated significant improvements in clinical parameters compared to baseline. In the sixth week, the O-TB and ST-TB groups showed significantly greater improvements in TQHI and BOP scores compared to the C-TB group (p < 0.05). By the third month, the ST-TB group maintained significantly lower TQHI and BOP scores, while the O-TB group's scores became similar to those of the C-TB group. ST-TB and C-TB groups had significantly lower GI scores than the O-TB group in all time points. Although the effectiveness of ST-TB was significantly higher than that of other toothbrushes, all toothbrushes demonstrated lower efficacy in the posterior region. Conclusions: The ST-TB was shown to be more effective in reducing gingival inflammation over three months, while it demonstrated similar efficacy to the O-TB in dental biofilm removal. Further research is necessary to substantiate these findings and to demonstrate the efficacy of this approach in promoting periodontal tissue health in patients with fixed orthodontic appliances. Trial registration: This study was registered with the National Library of Medicine Clinical Trials Registry Platform on 19/07/2024 as NCT06510179. [ABSTRACT FROM AUTHOR]

Background: This prospective study aims to investigate the comparative effects of clear aligners (CA) and traditional removable appliances (RA) on the cariogenic risk of patients in mixed dentition, focusing on the oral microbiome. Methods: 25 children were included and assigned into CA and RA groups. Supragingival plaque and saliva samples were collected, and clinical parameters including Decay-missing-filled teeth index (DMFT), Plaque Index (PI) and Gorelick Index (GI) were recorded before treatment (T0) and after 6-month follow-up (T1). DNA was extracted from supragingival plaque and saliva and analyzed via 16S rDNA gene sequencing. Results: Clinical parameters showed no statistically significant difference between groups at each time point or within group over time (p > 0.05). In both RA and CA groups, saliva exhibited significantly higher alpha diversity compared to supragingival plaque at T1, as indicated by the significantly higher Chao1 and Shannon indexes (p < 0.05). Regarding beta diversity, significant difference was observed in saliva and supragingival plaque samples between T0 and T1 within group RA (p < 0.05, Adonis), whereas no such significance was noted in the CA group (p > 0.05, Adonis). At the genus level, Lactobacillus exhibited a statistically significant increase in saliva and supragingival plaque of group RA from T0 to T1 (p < 0.05), and an increasing trend in the group CA without statistical significance (p > 0.05). At T1, Lactobacillus levels were comparable between groups, whereas species-level analysis revealed distinct cariogenic species. Conclusion: Both clear aligners and traditional removable appliances resulted in elevated cariogenic risk of patients in mixed dentition at the microbial level. Distinct alterations in cariogenic species were observed to be induced by various orthodontic appliances. [ABSTRACT FROM AUTHOR]

Objective: To compare the levels of functional impairments, discomfort and satisfaction experienced by those treated with full-mouth customized lingual appliances (Lingual appliances), full-mouth self-ligating bracket (Labial appliances), or upper lingual and lower labial appliances (Mixed appliances) using questionnaires. Materials and methods: Patients within one year of the end of treatment were included in the survey and given a questionnaire concerning different kinds of discomfort and difficulties during the treatment process. The questionnaires focused on the following aspects including speech difficulty, pain (lip, cheek or tongue), difficulty in chewing, difficulty in tooth brushing and overall aesthetics and comfortability. Ordinary one-way ANOVA Tukey's multiple comparison tests and Kruskal–Wallis tests were employed to analyze the data. Results: A total of 115 patients participated in the study. In terms of functional impairments and discomfort, the rate and degree of speech difficulty was significantly higher in the Lingual appliances Group than that in the Labial appliances Group. But there was no difference among the three groups for difficulty in chewing and tooth brushing. Both lingual and labial appliances caused a similar level of overall pain, however, those treated with lingual appliances experienced more tongue pain, and those treated with labial appliances experienced more cheek and lip pain. The most common sites of irritation were the tongue lateral and tongue tip in the Lingual appliances Group, tongue lateral and cheek in the Mixed appliances Group, and cheek and lower lip in the Labial appliances Group. In total, patients gave highest scores to mixed appliances for comfortability and lowest scores to labial appliances for aesthetics when it came to satisfaction. Conclusions: Lingual and labial appliances caused similar level of overall pain. Taking into account the overall comfortability, aesthetics and cost, the mixed appliances may be suitable for some patients who have aesthetic and comfort pursuits. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare the acceptability of removable acrylic appliances (RA) and Invisalign First (IF) clear aligners (Aligntech, USA) among children undergoing orthodontic treatment during the mixed dentition period, considering the severity of malocclusions. Methods: A total of 40 patients, aged 6 to 13 years, were recruited for the study. Malocclusion severity was evaluated using the Index of Orthodontic Treatment Need-Dental Health Component (IOTN-DHC). Patients completed the "Acceptance of Orthodontic Appliance Scale (AOAS)" via a face-to-face Google survey. To assess the reliability of the AOAS, the survey was resent to five patients after three months for a second response, and reliability analysis was conducted. Additionally, inter-rater reliability was evaluated by having all patients independently assessed by a second researcher. Data were analyzed using SPSS Statistics version 26 (IBM Corp., Armonk, NY, USA), with statistical significance set at p < 0.05. Results: Although no significant difference was found in IOTN-DHC scores, the IF group demonstrated significantly higher AOAS scores compared to the RA group (p = 0.014). Survey responses revealed noticeable distinctions between groups regarding speaking discomfort, preference for orthodontic appliances, and facial appearance comfort. A negative correlation (r = -0.477, p = 0.034) was observed between malocclusion severity and appliance acceptance. Clinical significance: This study underscores the significant superiority and advantage of IF over RA among pediatric orthodontic patients during the mixed dentition period. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of the universal and rapid autoclave cycles on the mechanical properties and surface roughness of nickel-titanium archwires following clinical use. Material and methods: Thirty-six NiTi archwires (0.016 × 0.022 inch) were equally divided into a control group (Group A) and 2 experimental groups (Group B & C). Wires in group A were tested in the "as-received" form. Wires in the two other groups were installed in patients mouth for 4 weeks, and then autoclaved using the rapid-cycle (Group B) or the universal-cycle (Group C). All wires were subjected to 3-point bending test to calculate the elastic limit, modulus of elasticity, spring-back, yield strength, resilience and toughness. Atomic force microscopy (AFM) was used for surface roughness qualitative and quantitative analysis. Results: Group B showed significantly higher values of elastic limit, modulus of elasticity, resilience, yield strength and toughness than the other two groups. No significant differences were detected between groups A and C (P > 0.05). Group B showed significantly lower average surface roughness than the other two groups, but no significant differences were detected between groups A and C (P > 0.05). Conclusions: The mechanical properties and surface roughness of clinically used NiTi wires were less affected by the universal-cycle than the rapid-cycle autoclaving. However, the difference between the effect of both autoclave cycles was diminutive. Clinical relevance: The mechanical properties and surface roughness of the tested NiTi wires were not notably altered by clinical use and autoclaving. [ABSTRACT FROM AUTHOR]

Background: Prosthetically guided orthodontics (PGO) can correct the malocclusion for better prosthetic rehabilitation in esthetic rehabilitation. Unlike conventional orthodontic treatment, only minor tooth movement is designed in PGO according to the requirement of subsequent restoration. For better appearance during the treatment, PGO is often performed with clear aligners, which have no metal brackets. It has been proven that the PGO with clear aligners can achieve generally satisfactory outcomes. However, its risk has not been fully known due to the paucity of relevant studies. Case presentation: Three patients who needed esthetic rehabilitation with mild malocclusion were included in this study. After evaluation, a prosthetic solution alone was considered insufficient to provide optimal outcomes. Thus, they were treated using PGO with clear aligners (Invisalign Go, Align Technology, Santa Clara, California, USA) and accomplished prosthetic rehabilitation subsequently. Dental history and X-ray examination revealed that endodontically treated teeth (ETT) existed in all the cases. Intraoral photographs were collected to compare the pre-treatment and post-treatment dentition. After PGO, posterior ETT did not maintain their position as scheduled and lost occlusal contacts, while all the anterior teeth, including anterior ETT, were moved to the designed position. Corresponding prosthetic rehabilitation was used to solve it after consulting with the patients. Conclusions: Occlusal contact loss of posterior ETT is a potential risk in PGO with clear aligners, affecting the orthodontic result. [ABSTRACT FROM AUTHOR]

Clear aligner therapy is a rapidly developing orthodontic treatment. 3D-printing technology, which enables the creation of complex geometric structures with high precision, has been used in dentistry. This article aims to summarize the various aspects of 3D-printing clear aligners and give an outlook on their future development. The traditional thermoforming technology is introduced and the principle and application of 3D-printed clear aligners and materials are introduced, as well as the application prospects of 3D-printed clear aligners. According to PRISMA statement, the relevant literature of 3D-printing clear aligner was searched in PubMed, Web of Science, Embase and other databases. We searched the related words in the MESH database and then carried out advanced searches. We read systematic review and conference papers to find the articles related to the subject and manually added and excluded articles by reading the title and abstract. The production of clear aligners combines computer-aided 3D analysis, personalized design and digital molding technology. The thickness and edges of the 3D-printed clear aligner can be digitally controlled, which allows appliance more efficiently fitted. Presently, the array of clear resins suitable for 3D-printing include photo polymeric clear methacrylate-based resin (Dental LT) (Form Labs, Somerville, Mass), aliphatic vinyl ester-polyurethane polymer (Tera Harz TC-85) (Graphy, Seoul, South Korea). They all have good biocompatibility. But no such material is currently approved on the market. Developing biocompatible resins and further improving the material's mechanical properties will be critical for the combination of 3Dprinting and clear aligners. However, the literature on 3D-printed clear aligners is limited and lacks clinical application. Further in vivo and in vitro tests, as well as additional exploration in conjunction with corresponding cytological tests, are required for the research on available materials and machinery for 3D-printing clear aligners. [ABSTRACT FROM AUTHOR]

Aim: Polyurethane-based aligners, created through photoinitiated free-radical polymerization, have been the subject of numerous studies focusing solely on their mechanical properties. In contrast, we investigate their thermomechanical properties, which are crucial for their efficacy. This paper aims to investigate the effects of different UV light exposure durations on the complex modulus of elasticity, tan delta, glass transition temperature, and the degree of conversion (DC). Methods: Aligners were printed using Tera Harz TC-85 and NextDent Ortho Flex resin with specific exposure times (2, 2.4, 3, 4, and 4.5 s for Tera Harz; 5, 6, 7, and 8 s for NextDent) and processed per manufacturer guidelines. The degree of conversion was analyzed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy, while Dynamic Mechanical Analysis (DMA) characterized the mechanical properties (complex modulus and tan delta) and the glass transition. Results: Tera Harz TC-85 showed a higher degree of conversion (90.29–94.54%), suggesting fewer residual monomers, which is potentially healthier for patients. However, its lower glass transition temperature (35.60–38.74 °C) might cause it to become rubbery in the mouth. NextDent Orto Flex, with a higher storage modulus (641.85–794.55 MPa) and Tg (49.36–50.98 °C), offers greater rigidity and stability at higher temperatures (greater than temperature in the oral cavity), ideal for orthodontic forces, though its lower degree of conversion raises health concerns. Conclusions: Tera Harz TC 85 generally achieves higher DC and more stable polymerization across different UV exposure times than NextDent Orto Flex. Optimal polymerization times significantly impact both the mechanical and thermal properties of these dental resins, with NextDent showing optimal properties at 7 s and Tera Harz benefiting from both very short and extended exposure times. [ABSTRACT FROM AUTHOR]

To compare preadolescents' smile outcomes after two different orthodontic treatments: RME/Schwarz plate (RS) and clear aligners (CAs). A sample of 31 patients (13 M, 18 F, mean age 8.3 ± 1.2 y.m) treated with RS and a sample of 28 patients (12 M, 16 F, mean age 7.9 ± 1.1 y.m) treated with CAS were included. Pre-treatment and post-treatment records were taken before the treatment (T1) and at the end of treatment (T2). Seventeen variables were evaluated. Both therapies were effective in smile width increase (RS = p < 0.02; CAs = p < 0.04) and buccal corridor reduction (RS = p < 0.02; CAs = p < 0.04). The intragroup analysis showed in the RS group an increase of incisor gingival display (p < 0.02), overbite (OVB) (p < 0.04) alongside a reduction of overjet (OVJ) (p < 0.01). Conversely, the CAs group evidenced a reduction in incisor gingival display (p < 0.04) and OVB (p < 0.01) with an increase in C angulation (p < 0.02) and maxillary incisor inclination (p < 0.04). An intergroup comparison evidenced a greater improvement in smile width, smile index and buccal corridor in the RS group with respect to the CAs group (p < 0.02; p < 0.02; p < 0.03). CAs were more effective in the management of gingival display, incisor position, midline correction (incisor gingival display p < 0.01; maxillary incisor position p < 0.04; maxillary dental midline p < 0.02), with a better control of OVJ (p < 0.01) and OVB (p < 0.02). The RS approach resulted in a greater smile width and a reduction in buccal corridor with respect to the CAs. The CAs provided a better management of both gingival display and smile aesthetics. [ABSTRACT FROM AUTHOR]

Background: Orthodontics is a speciality of dentistry that uses a plethora of devices made from myriad materials to manage various malocclusions. Prolonged contact of orthodontic appliances with oral tissues can lead to cellular damage, highlighting the need for biocompatible materials to mitigate health risks. Objectives: To analyze the genotoxicity and cytotoxicity produced by metal brackets and coated metallic brackets with polymeric and nanoparticle coatings in oral mucosal cells. Materials & methods: The current study compares the toxicity of 3 different types of orthodontic brackets with control groups of oral mucosal cells. Each of the three treatment groups consisted of 10 samples of orthodontic brackets: stainless steel brackets(Group 1), nanoparticle-coated brackets(Group 2), and polymeric-coated brackets(Group 3) exposed to corrosion eluates employing an oral biomimicry model. Two types of oral mucosal cells- Human Gingival Fibroblasts and Buccal Epithelial Cells were used to study the cytotoxic and/or genotoxic effects of the elutes. Intergroup comparisons were conducted using one-way analysis of variance, while scanning electron microscopy evaluated surface characteristic. Results: The interaction between metal ions and oral mucosal cells showed no statistically significant difference for toxicity assays between the three groups(p > 0.005). However, polymeric and nanoparticle-coated groups showed reduced cellular differentiation when compared with conventional stainless-steel brackets. Conclusion: This in-vitro study shows that polymeric or nanoparticle coating of conventional metal brackets aids in enhancing corrosion-resistant characteristics of orthodontic appliances and reduces the toxic oral environment created by metal release in the oral cavity. [ABSTRACT FROM AUTHOR]

Background: Extracting the premolars is an effective strategy for patients with bimaxillary dentoalveolar protrusion. Clear aligners (CAs) close the extraction spaces through shortening the length of aligners. The contraction force generated by the terminal of aligners makes the posterior teeth tip mesially, which is known as the roller coaster effect. This phenomenon is even worse in the 2nd premolar extraction cases. Posterior anchorage preparation is commonly used to protect the angulation of molars, taking the form of presetting distal tipping value. However, the distal tipping design aggravates the anchorage loss of anterior teeth simultaneously. This study aimed to explore the different anchorage loss of the posterior teeth when the 1st or 2nd premolars were extracted using CAs, respectively in maxillary and mandibular arches, further providing guidance for anchorage preparation design in clinical practice. Methods: Two bimaxillary finite element models with different extraction patterns were established to simulate the anterior en-masse retraction process of the CAs. In Model 1, the maxillary and mandibular 1st premolars were extracted, while in Model 2, the 2nd premolars were extracted. Finite element analysis methods were utilized to analyze the tipping angle of the anterior and posterior teeth. Results: Compared between two models, the anterior teeth exhibited a greater lingual inclination tendency and the posterior teeth exhibited a slighter mesial tipping tendency in Model 1 regarding individual tooth. The closer to the extraction spaces, the greater the tip, and the distal tipping tendency of the 1st premolars was more evident than the mesial tipping tendency of the 1st molars in Model 2. Compared between the maxillary and mandibular arches, the mesial tipping tendency of individual posterior tooth was more evident in the maxilla. In addition, the highest hydrostatic stress of the periodontal ligaments was concentrated on the cervical and apical parts directly adjacent to the extraction spaces, and it exhibited relatively uniform distribution in Model 1. Conclusions: The individual posterior tooth showed the same mesial tipping direction but to different degree when the 1st or the 2nd premolars were extracted during clear aligner treatment. Presetting anchorage preparation design for the posterior teeth is essential to alleviate the roller coaster effect, especially in the 2nd premolar extraction cases. Furthermore, larger anchorage preparation value should be proposed for the maxillary posterior teeth. [ABSTRACT FROM AUTHOR]

In many cases, the etiopathogenesis of oral cavity diseases depends on the presence of variants in some genes. Being able to identify these variants defines the possibilities and limits of therapies. This multidisciplinary case describes several pathologies of the oral cavity in a young patient affected by type 1 diabetes. The patient presented with an impacted palatal canine. Further investigation revealed cervical root resorption of the upper right central incisor. Genetic testing was performed for interleukin, VDR receptor genes, and the evaluation of periodontopathogenic bacteria. The mutational analysis carried out for the VDR polymorphisms and the IL1A, IL1B, IL6, and IL10 polymorphisms showed the presence of pathogenetic variants. The results for bacterial load showed the presence of periodontal pathogenes. The first intervention was the intentional replantation of the incisor. The second intervention was the orthodontic recovery of the impacted canine, using light forces and a hybrid anchorage with a miniscrew. At the end of orthodontic treatment, a crack was found in the upper left first premolar, which was extracted. Throughout treatment, non-invasive periodontal interventions were performed periodically to control periodontal inflammation. This case is an example of the integration of genetic analyses into the multidisciplinary diagnostic pathway. [ABSTRACT FROM AUTHOR]

The development of the finite element method (FEM) combined block polynomial interpolation with the concepts of finite difference formats and the variation principle. Because of this combination, the FEM overcomes the shortcomings of traditional variation methods while maintaining the benefits of current variation methods and the flexibility of the finite difference method. As a result, the FEM is an advancement above the traditional variation methods. The purpose of this study is to experimentally highlight the thermal behavior of two stomatognathic systems, one a control and the other presenting orthodontic treatment by means of a fixed metallic orthodontic appliance, both being subjected to several thermal regimes. In order to sustain this experimental research, we examined the case of a female subject, who was diagnosed with Angle class I malocclusion. The patient underwent a bimaxillary CBCT investigation before initiating the orthodontic treatment. A three-dimensional model with fully closed surfaces was obtained by using the InVesalius and Geomagic programs. Like the tissues examined in the patient, bracket and tube-type elements as well as orthodontic wires can be included to the virtual models. Once it is finished and geometrically accurate, the model is exported to an FEM-using program, such as Ansys Workbench. The intention was to study the behavior of two stomatognathic systems (with and without a fixed metallic orthodontic appliance) subjected to very hot food (70 °C) and very cold food (−18 °C). From the analysis of the obtained data, it was concluded that, following the simulations carried out in the presence of the fixed metallic orthodontic appliance, significantly higher temperatures were generated in the dental pulp. [ABSTRACT FROM AUTHOR]

Background: The demand for orthodontic treatment with aligners has recently increased, but their effects on awake bruxism (AB) behaviours have to be evaluated yet. Objectives: This investigation assessed if aligners can affect oral behaviours (i.e. tooth contact, teeth clenching, teeth grinding and mandible bracing) that are related with the AB spectrum. Methods: The investigation was performed in a sample of 32 consecutively recruited healthy adult patients who required orthodontic treatment. The study protocol involved three different sessions of 1‐week monitoring without aligners, with passive aligners and with active aligners, respectively. All patients underwent an orthodontic treatment with aligners and used a smartphone‐based application for a real‐time report (i.e. ecological momentary assessment [EMA]) of their AB behaviours. Recording time was set from 8.00 to 12.30 and from 14.30 to 22.00. Analysis of variance (ANOVA) was used to compare the average reported frequency for each activity within and between the different sessions. The coefficient of variation (CV) was assessed to evaluate daily fluctuations within the 7 days monitoring periods. Results: The average reported frequency of the relaxed condition was 64.9%, 63.0% and 60.0% during the sessions without aligners, with passive aligners and with active aligners, respectively. ANOVA showed no significant differences in any of the AB behaviours within (i.e. between 7 days of evaluation) and between the monitoring sessions (i.e. before orthodontic treatment, with passive aligners, with active aligners). No sex differences were detected, except for the 'tooth contact' report that showed a higher frequency in females. Conclusion: The impact of our results in the orthodontic field is not negligible; clinicians can find support for the hypothesis that from a global point of view, wearing or not wearing aligners (passive and/or active) does not influence the frequency of AB behaviours at the short term. [ABSTRACT FROM AUTHOR]

Background: Some orthodontic devices used in children share similar design principles to appliances used to treat obstructive sleep apnoea in adults. As well as treating malocclusion, orthodontic appliances used in children may therefore also have effects on the upper airway. Objective: A review of the literature to assess the effects of orthodontic treatment on the upper airway dimensions in children assessed on CBCT. Materials and Methods: Following registration of the protocol (PROSPERO CRD42023439056), a systematic electronic search of published studies was performed using several databases (PubMed; Scopus, Web of Science and Science Direct) in accordance with the PRISMA guidelines. Inclusion criteria were as follows: age under 18 years, orthodontic treatment with any appliance, a control group who received no treatment or a non‐active alternative treatment and airway measurement using CBCT. RoB‐2 and ROBINS‐I tools were used to assess risk of bias and quality of the evidence. Results: In total, 341 studies were identified following the initial search. Title and abstract screening resulted in 45 studies for further full‐text analysis. On completion of the screening process, a total of 23 studies met the inclusion criteria. Study interventions included functional appliances (10 studies), rapid maxillary expansion (RME) (9 studies), reverse‐pull headgear (1 study) and 4 premolar dental extractions (3 studies). The included studies had moderate to high risk of bias, and the quality of evidence was low. Conclusion: The scientific evidence shows that functional appliances are associated with significant improvements in both upper airway volume and constriction when used in children however, the effects on the nasal cavity are limited. RME was associated with a significant increase in nasal cavity and nasopharyngeal dimensions, but not the upper pharyngeal airway. Neither reverse‐pull headgear nor dental extractions were associated with any change in airway dimensions; however, the evidence is limited. Functional appliances may reduce the severity of obstructive sleep apnoea (OSA) in children. [ABSTRACT FROM AUTHOR]

Objective: This clinical study aimed to evaluate the difference in the time of application phase, employing the conventional and modified direct orthodontic bonding method. Materials and Methods: Thirty patients who needed orthodontic therapy with fixed appliances were randomly divided into two equal groups (n = 15): the control and experimental group, according to the bonding method applied. A total of 600 metal brackets inch slot 0.022 (Mini Sprint®, Forestadent, Germany) were bonded to incisors, canines, and premolars using the light‐cured adhesive Transbond XT (3M Unitek, Monrovia, CA, USA). The failure rates of the brackets were evaluated within 12 months. The independent samples t‐test was applied. The Chi‐square test and Fisher exact test were used for statistical analysis. Results: The initial bonding time using the modified method was significantly shorter (3.27 min or 17.1% per patient) compared with the conventional bonding method (p < 0.001). Number of failed brackets between the two methods did not differ significantly (p = 0.226). Conclusion: The time of the application phase in initial bonding using the modified method (experimental group) was shorter than in control group. There was no statistically significant difference in the number of bond failures between the two methods. Clinical Significance: The modified application phase of direct orthodontic bracket placement shortens the total bonding time and facilitates the manual work of orthodontists. [ABSTRACT FROM AUTHOR]

Social networks have become a widely used and accessible source of health-related information for patients, but this material is not always accurate or appropriate. The purpose of this study was to evaluate the quality of orthodontic information available on 2 of the most popular social media platforms. The authors conducted a systematic search of the literature that analyzed the quality of information regarding orthodontics on social networks and used recognized quality-evaluation methods, such as DISCERN, modified DISCERN, and the Quality Global Scale or the Video Information Quality Index, in the electronic databases of PubMed, Embase, and Scopus and through a manual search of gray literature. The authors identified a total of 534 potentially eligible articles, of which 22 eventually were included in the qualitative analysis. The application of the scales revealed that most of the content was of insufficient quality and lacked scientific rigor, precision, and support from reliable sources. The authors observed marked heterogeneity in the nature of the publications analyzed, with the most recurrent topics being general orthodontic treatment and the use of clear aligners. Social media platforms provide low-quality information to patients, which potentially can be harmful. These findings underscore the need to offer alternative ways to resolve patient queries before and during treatment and highlight the importance of promoting informed and responsible education regarding online information on orthodontic treatments. [ABSTRACT FROM AUTHOR]

This study aimed to use a carboxybetaine methacrylate (CBMA) copolymer solution to surface treat 3D printed clear aligners at different fabrication stages, to impart antifouling properties, and assess the surface treatment at various fabrication stages' impact on physico-mechanical characteristics. Surface treatments using a blend of 2-hydroxyethyl methacrylate (HEMA) and CBMA, termed CCS, were performed at various stages of 3D printed clear aligner fabrication. Experimental groups, CB1, CB2, and CB3, were determined by the stage of surface treatment during post-processing. CB1, CB2, and CB3 received treatment before post-curing, after post-curing, and after post-processing, respectively. Untreated samples served as controls. Physical and mechanical properties were assessed through tensile testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and UV-Vis spectroscopy. The surface was further characterized through scanning electron microscopy and contact angle measurements. The cytotoxicity was assessed with 7-day elution and agar diffusion assays. Lastly, bacterial biofilm resistance was evaluated using confocal laser scanning microscopy. Crystal violet assay was performed using Streptococcus mutans. Surface treatment during CB1 stage exerted the most significantly unfavorable influence on properties of the 3D printed aligner resin. CB2 samples showed the maximum preservation of translucency even after 7-day aging. CB2 and CB3 phases showed enhanced hydrophilicity of sample surfaces with reduced adhesion of multispecies biofilm and S. mutans. Application of CCS surface treatment immediately after post-curing (CB2) can enhance the biofilm resistance of 3D printed clear aligners while maintaining high fidelity to optical translucency and constituent mechanical properties. [ABSTRACT FROM AUTHOR]

Clear aligners are popular orthodontic tools because of their relatively aesthetic appearance and convenience of use. Nevertheless, bodily tooth movements still present challenges. This study evaluated various configurations of attachments placed on the mandibular canine in terms of the efficiency of canine bodily movement and correction of tipping. A finite element model of the mandible was constructed to investigate the effects of various attachment configurations on the overall bodily movement and undesirable tipping of a mandibular canine. Canine movements were categorized into four types, namely tipping and bodily movements in the mesial and distal directions. The size and shape of the attachments were fixed, but their placement and orientation were varied. Five and seven attachment configurations were evaluated for their influence on tipping and bodily movements, respectively. Attachment configuration significantly influenced mandibular canine tipping. The mesial occlusal–distal cervical and mesial occlusal–mesial cervical configurations had notable effects on mesial tipping, and the mesial occlusal–mesial cervical configuration excelled in distal tipping by increasing strain by 33.1%. The mesial occlusal–mesial cervical attachment configuration consistently had superior efficiency in facilitating both mesial and distal bodily movements of the canine. The mesial occlusal–mesial cervical attachment configuration excelled in all four types of canine movement. Irrespective of the attachment configuration, canines tend to move overall with slight tipping due to skeletal resistance and their center of rotation. The attachment configuration is crucial to the success of clear aligner treatment and must be carefully considered in clinical practice. [ABSTRACT FROM AUTHOR]

Invisible orthodontic treatments are becoming increasingly popular, and numerous brands of invisible aligners are now available. However, concerns remain about the safety of the materials used in these products. This study aimed to assess the cytotoxic effects of both original and thermoformed thermoplastic materials used in orthodontic aligners on human periodontal ligament (HPDL) cells in vitro. The experiment used six different brands, each containing three types of thermoplastic materials, Polyethylene terephthalateco-1, 4-cyclohexylenedimethylene terephthalate (PETG), thermoplastic polyurethane (TPU), and copolyester polyethylene terephthalate (PET). The original sheets and the thermoformed materials were soaked in a culture medium for seven and fourteen days, and then applied to cultured human periodontal ligament cells. Cells were harvested on the first, third, and fifth days after application, and their viability was analyzed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. The findings revealed that some thermoformed materials, notably PETG, exhibited lower survival rates compared to their non-thermoformed versions. However, other materials such as TP and PET maintained over 70% cell viability, indicating only minor cytotoxic effects. These findings highlight the need for further research into the long-term biocompatibility of these materials but generally affirm their safety for use in orthodontic aligners under the tested conditions. [ABSTRACT FROM AUTHOR]

Orthodontic treatment is often mandatory to improve the patient's health condition. However, the fixed appliance can create additional plaque retention areas, which can increase the risk of caries development. Clinically, one can observe various effects of fixed appliance treatment on caries prevalence. This study aims to analyze to what extent orthodontic therapy with fixed appliances is a risk factor for developing caries in pediatric and adult patients. The keywords used in the search strategy were as follows: ("caries" AND "caries risk" AND "caries experience" AND" "orthodontic treatment" OR "fixed appliance"") and ("caries experience" AND "orthodontic treatment"). From 808 potential articles, 15 were included in the review. In individuals undergoing fixed orthodontic therapy, several factors can increase the risk of caries during fixed orthodontic treatment, such as salivary composition, oral dysbiosis and plaque accumulation. On the other hand, factors that reduce caries risk are, i.e., oral hygiene self-awareness and previous orthodontic treatment. In most studies which used the Decayed, Missing, and Filled Teeth (DMFT) index, there were no significant differences between the values obtained before orthodontic treatment and after the treatment. Moreover, it is easier for a patient with aligned teeth to remove plaque. In the young population, fixed orthodontic treatment appears to reduce the incidence of caries. In the adult population, fixed orthodontic treatment increases the risk of dental caries. However, education on proper oral hygiene during orthodontic treatment can reduce the risk of dental caries. The study protocol was registered in the PROSPERO database (PROSPERO CRD42022356628). [ABSTRACT FROM AUTHOR]

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Background: To compare and investigate the effects of intraoral ageing on the thickness of one group of directly printed and two groups of thermoformed aligners on the labial surface of maxillary central incisors. Materials and Methods: Six groups (12 samples per group) were included in this prospective in vivo experiment. Groups DP‐Clin, INV‐Clin and CA‐Clin consisted of directly printed (Tera Harz TC‐85 DAC resin), thermoformed (Invisalign, PU based polymer) and in house thermoformed (CA‐Pro, PET‐G based polymer) aligners, retrieved after 1 week of intraoral service. Groups DP‐Ctr, INV‐Ctr and CA‐Ctr included unused aligners samples. Thickness measurements were conducted using confocal laser scanning microscopy (CLSM). Data that underwent log‐10 transformation was analysed by multiple linear regression analysis (p <.05). Results: Statistically significant differences were found between the materials in both Clin and Ctr categories (p <.001). Group DP had the highest thickness among the groups and the least thickness was observed in the CA group (p <.001). However, intraoral ageing did not significantly affect the aligner thickness of any groups. Conclusions: Both thermoforming and direct printing of clear aligners led to thickness deviations in terms of increase for printed aligners and decrease for thermoformed aligners. Intraoral ageing did not affect the aligner thickness in any of the groups. [ABSTRACT FROM AUTHOR]