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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.)

Objective: To aim at the preparation and characterization of a chitosan and betel leaf extract biopolymer followed by an assessment of mechanical and antibacterial properties. Material and Methods: A chitosan-betel leaf stock solution was prepared and dip-coated on thermoformed aligner cubes. The groups (five samples per group) involved were one control (only chitosan coating) and three test groups based on the duration of coating (coating with chitosan and betel extract coated for 5, 10, and 15 minutes, named B5, B10, and B15 respectively). The coating of the samples was confirmed by an FTIR test and anti-microbial properties were assessed by the disc diffusion method. Wear resistance assessment of the coating was carried out by scratch test. Results: Coating of the aligners with the extract was confirmed with FTIR. The zone of inhibition against S. mutans was noted to be the widest for aligners coated for 15 minutes (7± 0.5mm), and the intergroup difference was statistically significant (p

ABSTRACT Introduction: Social media enhanced access to information, making it easier to share dental treatments. Objective: This study aimed to conduct a descriptive analysis of the clinical cases published on the Align® Global Gallery platform. Material and Methods: A retrospective cross-sectional study of 1,582 cases was conducted, data extracted referred to the following basic information: case number; patient’s age; reported gender; Invisalign® package modality; treatment time; aligner exchange protocol; total number of aligners per arch; type of retainers, and inclusion of initial and final panoramic and cephalometric radiographs. Results: The majority were young (mean age 24.6 years, SD = 11.6), female patients (69.1%) with Class I malocclusion (39.4%) and crowding (77.9%). Comprehensive treatment was common (66.5%), with an average treatment time of 18 months (SD = 8.56; 95% CI = 17.6-18.5), with the most frequently reported aligner exchange protocol being 7 days (49.5%), with an average of 50.6 aligners in the upper arch (SD = 26.9; 95% CI = 49.2-51.9), and 48.7 in the lower arch (SD = 26.1; 95% CI = 47.4-50.0). Arch expansion (66.9%) and interproximal reduction (59.7%) were common approaches, while extractions were rare (4.3%). In most cases, initial lateral cephalometric (80.4%) and panoramic (93.3%) radiographs were presented. However, the final radiograph count dropped, with lateral cephalometric at 69.2%, and panoramic at 82.2% of cases. Conclusion: Cases in the Align®Global Gallery mostly feature Class I patients with crowded teeth, treated with expansion and interproximal reduction. The absence of standardized information and post-treatment data restricts the applicability of these findings to broader Invisalign® treatment trends.

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.)

Background: There is limited knowledge of the possible side‐effects of clear aligners on jaw function. Objectives: To determine the short‐term effect of passive clear aligners (PCAs) on masticatory muscle activity (MMA), occlusal discomfort (OD) and temporomandibular disorder (TMD) symptoms in adults with different levels of self‐reported oral parafunction. Materials and Methods: Participants were screened for oral parafunctional behaviours using the oral behavioural checklist. Respondents in ≥85th and ≤15th percentiles were invited to participate and allocated to a high (HPF: N = 15) or low (lower parafunction [LPF]: N = 16) parafunction group. Participants underwent a TMD clinical examination; somatisation and somatosensory amplification were assessed by questionnaires; OD and stress were assessed by visual analogue scales. While wearing PCAs, awake‐time MMA was assessed three times over 9 days using a wearable electromyography device, along with OD, stress and TMD symptoms. Results: The wearing of PCAs was associated with a significant decrease in mean contraction episode amplitude in both groups (p = 0.003). OD levels increased and remained raised in all participants after insertion of the PCAs (p < 0.001), more so in the HPF group (p = 0.048). The HPF group had higher somatisation scores (p = 0.006) and reported more TMD symptoms at all time points (p ≤ 0.004). No significant changes in stress or TMD symptoms were found in either group during the study period. Conclusions: PCAs were associated with a decrease in MMA in all participants. HPF individuals had greater somatisation and reported greater discomfort when wearing PCAs than LPF individuals. [ABSTRACT FROM AUTHOR]

The mechanical properties of polyurethane dental aligners have been studied in an oral environment at 37°C and subjected to thermal cycling between 5°C and 55°C for long periods of time at different mechanical stresses. The aim is to determine the efficacy of the orthodontic aligner at different stress levels, the effect of thermal cycling with therapy time on tooth position correction. Sixty aligners with the same design were studied applying tensions of 0, 3 and 30 N and determining the deformation at different times from 1 to 760 h. Half of these aligners were subjected to stresses submerged in artificial saliva at 37°C and the other half were subjected to thermal cycles between 2°C and 55°C in salivary medium. Deformation was determined using a high-resolution stereo magnifier and ImageJ image analysis software. Water adsorption by the polyurethane was determined at the different test times. The results showed that in the unloaded aligners there is no appreciable deformation, but with thermal cycling there is a light shrinkage of the aligner due to the semi-crystallization process (ordering of polymeric chains) of the polyurethane. When applying loads of 3 and 30 N, creep curves with constant deformation transition zones can be seen. The transition zones decrease as the applied mechanical load increases. In addition, the significant effect of thermal cycling on the reduction of the transition zone of the aligners has been demonstrated. The transition zones are optimal for dental correction as constant stresses are exerted for tooth movement. The effect of thermal cycling shortens the constant deformation zone and reduces tooth alignment time. It was observed that the absorption of water in the aligner is constant after 1 h of immersion and does not exceed 0.4% by weight of absorbed water.

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.)

Objectives: The aim of the present study is to assess the means and methods being suggested by Greek orthodontists to their patients for cleaning their removable devices.Materials and Methods: A questionnaire survey was conducted among a total of 418 Greek orthodontists found from the registry of orthodontists in Greece. The clinicians were asked about the means and methods of daily cleaning they usually advise their patients for removable appliances. Furthermore, the questionnaire included questions related to possible complications of these devices and data about the use and type of applied devices.Results: From 418 Greek orthodontists, 279 filled the questionnaire and participated in this study. All but one reported that they use removable appliances in their practice for patients of almost any age. All orthodontists recommend routine manual toothbrushing, but the majority of them also suggest at the same time other oral hygiene aids complementary to brushing, such as immersion in denture cleaners (70.06%), in disinfecting solutions (12.73%) and in vinegar (36.94%). Some 15% of all the practitioners advise the use of ultrasonic instruments for cleaning removable orthodontic appliances. At last, clinicians have faced complications from the use of removable devices in the oral cavity at a statistically significant percentage. The most usual is trauma of the mucosa, mycosis and hyperplasia.Conclusion: Greek orthodontists use removable orthodontic appliances, active or passive, in their practice. Brushing with a toothbrush and the use of cleaning products for removable prostheses are the preferred methods for cleaning removable orthodontic appliances regardless of the orthodontic specialty programme they had graduated from. [ABSTRACT FROM AUTHOR]

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.)

Purpose: The reliability of combining natural teeth and implants in one removable prosthesis is controversial. This systematic review was conducted to evaluate the prognosis of combined tooth/implant-supported double-crown-retained removable dental prostheses (DCR-RDPs) and to compare them with solely implant-supported prostheses with a minimum observation period of 3 years. Materials and Methods: Electronic database (PubMed, Embase, Central, and SCI) and manual searches up to August 2016 were conducted to identify human clinical studies on tooth/implant-supported DCR-RDPs. Literature selection and data extraction were accomplished by two independent reviewers. Meta-analyses of survival and complication rates were performed separately for combined tooth/implant-supported and solely implant-supported DCRRDPs. Results: Among the initially identified 366 articles, 17 were included in a quantitative analysis. The estimated overall cumulative survival rate (CSR) for implants in combined tooth/implant-supported DCRRDPs was 98.72% (95% confidence interval [95% CI]: 96.98% to 99.82%), and that for implants in solely implant-supported DCR-RDPs was 98.83% (95% CI: 97.45% to 99.75%). The summary CSR for abutment teeth was 92.96% (95% CI: 85.38% to 98.12%). Double-crown-retained dentures with both abutment types showed high CSRs, most of which were approximately 100%. Regarding prosthetic maintenance treatment, the estimated incidence for patients treated with combined tooth/implant-supported RDPs was 0.164 (95% CI: 0.089 to 0.305) per patient per year (T/P/Y) and that for patients restored with solely implant-supported RDPs was 0.260 (95% CI: 0.149 to 0.454) T/P/Y. Based on four studies with combined tooth/implant-supported DCR-RDPs, no intrusion phenomena were encountered. Conclusion: Subject to the limitations of the present review, combining remaining teeth and implants in DCR-RDPs is a reliable and predictable treatment modality for partially edentulous patients. Comparable high survival rates and minor biologic or technical complications are observed for combined tooth/implant-supported and solely implant-supported DCR-RDPs. Due to the heterogeneity of the included studies, the results must be interpreted with caution. [ABSTRACT FROM AUTHOR]

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.)

Background: This study focused on the aging mechanism and degradation of mechanical and structural features of elastodontic appliances (EA) under artificial and intraoral aging to achieve oral myofunctional therapy with particular removable silicone elastomer devices., Materials and Methods: EAs artificially aged in saliva with different pH values were investigated through cyclic compression testing along with characterization techniques (Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy), and characterization analysis was also performed on clinically retrieved EAs., Results: Artificial aging was found to have minimal effect on the structural properties of EAs, and intraorally aged samples showed perceptible micro-morphology. The Mullins index and peak stress decreased (P<0.01), while the compression set increased with prolonged aging time. Samples in alkaline saliva showed the largest Mullins effect (P<0.05)., Conclusions: The aging mechanism of the elastomer was found to be the crosslinking of main chains and scission of side chains. The presence of OH- enhanced the rupture degree of side bonds. The decline in viscoelastic properties was shown to be more severe with longer service durations., Clinical Relevance: Research on how the salivary environment and pH affect the aging characteristics of EAs is vital for guiding clinical applications and future modifications to extend their clinical lifetime., (© 2024. The Author(s).)

The etiology of temporomandibular disorders (TMDs) is remarkably diverse. This case report highlights the use of clear aligners as a probable cofactor of TMD in an adult patient. A 56-year-old woman who presented with a chief concern of crowding was missing teeth in both arches and had generalized tooth wear, an indistinct history of temporomandibular joint musculoskeletal pain, and a self-reported history of clenching. Based on the patient's preferences, clear aligner therapy (CAT) was initiated with a limited treatment goal of providing improved esthetics by reducing the overjet, expanding the arches, and aligning the anterior teeth. A few weeks into CAT, the patient developed acute masticatory facial pain. Therefore, the course of CAT was adjusted in favor of an individualized protocol to alleviate her occlusal symptoms until orthodontic treatment was completed. Dental providers must consider the potential contributory role of CAT in TMDs in patients who adapt poorly to occlusal changes and offer a patient-centered approach to manage the problem., Competing Interests: No conflicts of interest reported.

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., (© 2024 Special Care Dentistry Association and Wiley Periodicals LLC.)

Objectives: To compare effectiveness of two protocols for correcting deep bite in growing patients using a removable anterior bite plane (RABP): full-time wear with appliance on during meals (F + M) vs off during meals (F - M) and to explore the relationship between average daily duration of wear and overbite (OB) correction rate, stratified by the wear protocol., Materials and Methods: Thirty-two growing patients with deep bite (mean age = 10.94 ± 2.17 years) were randomly assigned to the F + M (n = 16) or F - M (n = 16) group. Cephalometric radiographs were taken at baseline (T0) and when normal OB was achieved (T1). Duration of wear was recorded by a TheraMon microsensor within the appliance. A best-fit regression model for the relationship between daily duration of wear and OB correction rate was determined (α = 0.05)., Results: Both groups exhibited similar baseline characteristics and cephalometric changes, ie, molar extrusion, and incisor intrusion and proclination in both arches (P < .05), and intergroup differences were not significant. Here, F + M exhibited significantly faster rates of deep bite correction (1.83 ± 1.18 vs 1.08 ± 0.62 mm/month; P < .05) and mandibular molar extrusion (0.46 ± 0.25 vs 0.30 ± 0.18 mm/month, P < .05) compared with F - M. Best-fit regression models for relationship between daily duration of wear and OB correction rate were exponential for both F + M (R2 = 0.53) and F - M (R2 = 0.74)., Conclusions: Here, F + M and F - M protocols resulted in comparable cephalometric changes among deep bite growing patients. However, the F + M group exhibited a faster correction rate. Daily duration of wear positively correlated with OB correction rate in an exponential manner., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

Introduction: This prospective study compared pain perception, intensity, and analgesic use among patients treated with fixed appliances (FAs) and clear aligners (CAs) over 6 months., Methods: Digital surveys were collected from 87 adult patients treated with CA or FA from 2 orthodontic offices. The 7-item survey was sent at 3-time points (preappointment, 2-day postappointment, and 7-day postappointment) for each appointment. Wilcoxon, t test, and Fisher exact chi-square tests were performed with significance set at 0.05., Results: The FA group had a higher rate and intensity of pain 2 days after the second, third, and fifth appointments (P <0.030). At 7 days postappointment, the FA group had a higher rate and intensity of pain for the first and fifth appointments. Dull pain was reported the most in both groups, with a proportion of FA patients reporting throbbing (31%) or sharp (20%) pain (P = 0.035) at 2 days postappointment. The CA group reported the most pain at rest, whereas the FA group reported chewing as the most painful (P = 0.002). The FA group had a higher rate of analgesic consumption after the first appointment (P = 0.037)., Conclusions: Both the FA and CA groups experienced similar rates and intensities of pain 2 days after the delivery of appliances at the first appointment. Although CA pain intensity remained minimal, FA pain peaked 2 days postappointment whenever a new orthodontic stimulus was introduced and remained elevated 7 days postappointment when that stimulus was a new archwire material., (Copyright © 2024 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of the study was to determine how the electrical activity of the temporalis, masseter and sternocleidomastoid muscles differs in children with reduced transverse jaw dimension compared to children with normal occlusion., Design: It was a experimental study. Thirty-seven patients were included in the study. 18 in the study group received orthodontic treatment with removable appliances and 19 subjects were classified as normal occlusion subjects in the control group. A panoramic X-ray and digital intraoral scan were taken, followed by an surface electromyography of three muscle pairs (temporalis muscles, masseter muscles, sternocleidomastoid muscles) in resting position, while clenching and clenching on cotton rollers., Results: There was significantly greater activity in the experimental group than in the control group comparing muscles: temporalis muscles and masseter muscles in the resting position. Additionally, significantly greater activity of muscles in the control group was found during clenching. However, the asymmetry index of muscles indicates that there is significantly greater asymmetry of muscles activity in the experimental group. Compared to children with normal occlusion, children with a narrowed transverse dimension of the jaw have statistically significant differences in the bioelectrical activity of the temporalis, masseter and sternocleidomastoid muscles, as well as greater asymmetry in the bioelectrical voltage of the masseter muscles., Conclusions: Patients with reduced transverse dimension of the jaw are characterized by increased resting activity of the masticatory muscles and reduced functional activity of the masticatory muscles. These patients have increased asymmetry in the bioelectrical tension of the masticatory muscles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objectives: This study aimed to determine the overall oral health statuses of patients with fixed orthodontic appliance and clear aligner, as well as their oral hygiene management behaviours and satisfaction., Methods: We selected 40 participants (20 each with fixed orthodontic devices and clear aligners) who visited a dental clinic. We conducted a survey to determine the oral hygiene management behaviours of the subjects and their satisfaction with their orthodontic treatment. Three measurements were also conducted at 4-week intervals to determine the oral health statuses of the subjects., Results: The Löe and Silness gingival index of patients with fixed orthodontic appliances indicated moderate gingivitis (1.1 ± 0.3), and those with clear aligners had mild gingivitis (0.6 ± 0.4) (p < 0.001). The modified O'Leary index also indicated that the degree of dental plaque deposition in the oral cavity was lower in patients treated with a clear aligner (43.0 ± 18.2 points) than in those treated with a fixed orthodontic (28.1 ± 10.9 points) (p = 0.004). Regarding oral hygiene management, the fixed orthodontic group received scaling more frequently (p = 0.006), received more oral health education (p < 0.001) and had a longer brushing time (p = 0.008) than the clear aligner group. No significant difference was observed in satisfaction between the fixed orthodontic appliance and the clear aligner., Conclusions: Regarding the oral health status by orthodontic appliance type, the clear aligner group had the advantages of reduction in dental plaque attachment and gingival health. The fixed orthodontic group exhibited better oral hygiene management behaviours. Satisfaction with orthodontic treatment was found to be similar for the two device types., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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.

Purpose: The aim of this retrospective cohort study was to evaluate the long-term effects of interceptive orthodontic treatment with a removable expansion plate, based on transversal, sagittal, and vertical parameters., Methods: A total of 90 patients needing interceptive treatment due to a crossbite or space deficiency were included. Records consisting of clinical photos, radiographs, and digital dental casts were collected for evaluation at two time points: the start of interceptive treatment (T0) and the start of comprehensive treatment (T1). Molar occlusion, overjet, overbite, presence and type of crossbite, mandibular shift, and transversal measurements were recorded for comparison., Results: After expansion with removable appliances, a significant increase in intermolar width was achieved and could be maintained over the observation period (p < 0.001). However, no significant changes regarding overjet, overbite, or molar sagittal occlusion were observed. Crossbite correction was successful in 86.9% of patients with unilateral crossbite and in 75.0% of patients with bilateral crossbite (p < 0.001)., Conclusion: Early expansion with a removable expansion plate is a successful method to correct crossbites and increase intermolar width in the early mixed dentition phase. Results remain stable until the start of comprehensive treatment in the permanent dentition., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

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., (© 2024. The Author(s).)

Objective: The aim was to assess adult patients' weight changes during the initial phase of orthodontic treatment (OT) with clear aligner therapy (CAT) versus fixed bracket systems (FBS)., Methods: This pilot prospective cohort study included systemically-healthy adults who were treated with CAT or FBS. Participants with eating disorders and/or undergoing dietary programs were excluded. Weight was assessed using a calibrated digital scale at the start of OT (T1), 6-8 weeks (T2), and 12-16 weeks (T3) after starting OT. A questionnaire was used to record demographic variables, diet and exercise habits, self-reported compliance and discomfort during OT, and use of analgesics. Repeated measures analysis of variance was used to assess the association between treatment type (FBS versus CT) and time-period (T1, T2, T3) on participants' weight while adjusting for baseline covariates such as age, gender, height, and weight., Results: Forty-two participants (CAT group: 22 and FBS group: 20) were analysed. In the CAT group, there was a slight initial mean weight gain of 0.2 Kg (~ 0.4 pounds) (T2-T1), and 0.8 Kg (~ 1.7 pounds) overall mean weight loss between T1 and T3. For the FBS group, there was a slight initial weight loss of 0.3 Kg (~ 0.7 pounds) (T2-T1) and no overall change between T1 and T3. Treatment type (CAT versus FBS) was not significantly associated with weight changes during the initial phase of OT., Conclusions: There were no significant differences in the weight changes during the initial phase of OT with CAT compared with FBS., Clinical Relevance: Clear aligner therapy should not be advertised as a weight loss strategy., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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., (© 2024. The Author(s).)

Introduction: This study aimed to investigate whether there was a difference between the planned and achieved lingual root torque of the maxillary central incisors in patients treated with an initial series of Invisalign (Align Technology, Santa Clara, Calif) aligners in which >10° change in the inclination of these teeth was prescribed via the ClinCheck facility., Methods: The pretreatment, planned, and the digital models after wear of the initial series of aligners regarding adult patients who satisfied selection criteria and were treated using the Invisalign appliance were measured using the Geomagic Control X software (version 2017.0.3; 3D systems, Rock Hill, SC)., Results: A sample of 63 patients with 126 maxillary central incisors satisfied the inclusion criteria. The mean accuracy of the planned torque change of the maxillary central incisors that was achieved was 41.9%. A clinically significant shortfall (≥5°) was detected in 78.6% of the incisors, with the majority showing an underexpression between 10°-15°. Linear regression analyses indicated that weekly or biweekly wear protocols or the presence or absence of power ridges did not influence the accuracy of planned torque expression (P >0.05)., Conclusions: The changes in torque expression with an initial series of Invisalign aligners were less than half of what was planned in patients in which at least a 10° change in lingual root torque of these teeth was prescribed. The presence of power ridges and the aligner change protocol did not appear to significantly affect the accuracy of maxillary central incisor torque expression., (Copyright © 2024 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study aimed to evaluate the effectiveness of Dental Monitoring (DM) (Dental Monitoring SAS, Paris, France) compared with conventional monitoring (CM) during active orthodontic treatment., Methods: The Peer Assessment Rating (PAR) index was used to evaluate the pretreatment and posttreatment records of 51 patients, with 26 in the CM group and 25 in the DM group. The change in weighted PAR was analyzed to assess the effectiveness of treatment., Results: The chi-square test revealed that the CM group had a higher percentage of patients in the great improvement category compared with the DM group. However, this difference was not statistically significant (P = 0.192). A repeated measures general linear model demonstrated significant improvement over time (P <0.001), with no statistically significant group differences noted between CM and DM (P = 0.181) and no statistically significant time-by-group interaction (P = 0.299)., Conclusions: Both CM and DM showed significant improvements in weighted PAR scores, but no statistically significant difference is present between the 2 groups., (Copyright © 2024 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objective: This study aimed to investigate the biomechanical effects of clear aligner (CA) with different shape designs at extraction space (CAES) area during space closing., Materials and Methods: A finite-element method (FEM) model of mandibular dentition, periodontal ligaments, attachments, and corresponding CA was established. The connecting rod design of CAES was modelled for the control group. Eight test groups with different heights of CAES from -4 mm to +4 mm were designed. Tooth displacement tendencies were calculated. The maximum principal stress in PDLs, teeth, and CAs was analysed. Both global coordinate system and local coordinate system were also used to evaluate individual tooth movements., Results: Across all groups, stresses concentrated on the lingual outer surface of CAESs. For the lowered CAES groups, both the stress value and the stress distribution area at CAESs were increased. The lowered CAES groups showed reduced movement in anterior teeth and less tipping tendency of the canines., Conclusion: The shape of CAES has a biomechanical impact on anterior teeth movement and should be considered in aligner design. The results suggest that increasing the height of CAES can enhance anterior teeth retraction, while lowered CAES may facilitate controlled root movement. Changes in the shape of CAES represent a potential direction for biomechanical improvement of clear aligner in extraction cases and are worth exploring., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The study herein evaluated and compared the efficacy of Clear Aligners (CA) and Twin-Block (TB) appliances as the early orthodontic treatments of developing class II division 1 malocclusion. Twenty-four patients each for CA (11.73 ± 0.33 y) and TB (11.87 ± 0.34 y) groups were selected according to the inclusion and exclusion criteria. The cephalometric X-rays and intraoral photos were taken for the patients after nearly 12 months of treatment. Treatment impacts were evaluated by the molar correction and overjet reduction. The vertical and sagittal changes were analyzed through cephalometric measurements. Sella-nasion-point B angle (SNB), point A-nasion-point B angle (ANB), Wits Appraisal (AO-BO) and overjet were statistically significant regarding the sagittal changes analyzed before and after the treatments in both groups, respectively. So, no significant difference was noted in the sagittal changes between CA and TB groups. However, for the vertical changes, OP (occlusal plane) angle of CA group and OP angle, AFH (anterior facial height) and PFH (posterior facial height) of TB group were statistically significant. Moreover, the Z angle and cranial facial difficulty (C.F. difficulty) were also statistically significant in both groups. Class II children with retrognathic mandible are effectively treated by employing the CA, which has almost the same impact as of TB in sagittal and vertical changes. Resultantly, the patient profile is improved. The CA and TB treatments thus minimize the subsequent treatment difficulty by reducing the C.F. difficulty., Competing Interests: The authors declare no conflict of interest., (©2024 The Author(s). Published by MRE Press.)

Objectives: To assess the influence of Invisalign precision bite ramp use on skeletal deep overbite correction and root length and volume of maxillary anterior teeth., Materials and Methods: This was a retrospective study of 60 adults with skeletal deep overbite. Patients were divided into three groups: Invisalign (Align Technology, San Jose, Calif) with precision bite ramps (Invisalign with Bite Ramps [IBR] = 12), Invisalign with no bite ramps (INBR = 22), and full-fixed appliances (FFA = 26). Cone beam computed tomography records at T1 (pretreatment) and T2 (posttreatment) were used to measure eight skeletal, nine dental, and three soft-tissue cephalometric variables. Maxillary anterior teeth root length (mm), root volume (mm3), and percent root volume loss between T1 and T2 (%) were also recorded., Results: Significant changes from T1 to T2 among the three groups were seen in ANB(o), lower face height (%), ODI (overbite depth indicator) (o), and U1-SN (o). Reduction in root length was significantly less (P < .001) in the INBR and IBR groups compared to the FFA group. Reduction in root volume and percent volume loss were significantly higher in the INBR group compared to the IBR group (P < .001), but the difference between the two Invisalign groups and the FFA group was not significant., Conclusions: Skeletal deep overbite correction using Invisalign with or without bite ramps is comparable to FFA. Reduction in root length was significantly less with Invisalign compared to FFA. Bite ramps influenced root volume and volume loss but not root length., (© 2024 by The EH Angle Education and Research Foundation, Inc.)

Introduction: This study aimed to evaluate the efficacy of Invisalign First Phase I treatment compared with tooth-borne rapid maxillary expansion (RME) in mixed dentition patients by examining changes in palatal volume, palatal surface area, and maxillary interdental transverse measurements., Methods: In this open-label, 2-arm, parallel, randomized controlled trial, patients with a posterior transverse discrepancy ≤6 mm were allocated into the clear aligner therapy (CAT) group (Invisalign First Phase I treatment) and RME group (tooth-borne RME) according to a computer-generated randomization list immediately before the start of treatment. Digital models were obtained before the beginning of the treatment (T0) and at the end of the retention period/treatment (T1) using an intraoral scanner. Palatal volume was measured as the primary outcome, and palatal surface area and intermolar and intercanine transverse widths at the cusps and gingival level were measured as secondary outcomes. Patients and interventionists were not blinded because of the nature of the intervention., Results: Out of 50 patients, 41 (19 males and 22 females; mean age, 8.12 ± 1.53 years) were enrolled and divided into 2 groups: 20 in the CAT group and 21 in the RME group. Two participants did not receive the allocated intervention for different reasons (1 patient discontinued the intervention in the CAT group, and another patient was lost to follow-up in the RME group). Thus, 19 patients (5 males and 14 females; mean age, 8.48 ± 1.42 years) were analyzed from the CAT group, and 20 patients (12 males and 8 females; mean age, 7.83 ± 1.19 years) from the RME group. Regarding intragroup comparisons, all outcome measures significantly increased from T0 to T1 in both groups. In terms of intergroup comparisons, there were no significant differences in the variation (Δ) of outcome measures between the 2 groups from T0 to T1, except for the intermolar width at the gingival level (P <0.005). The change in palatal volume was 532.01 ±540.52 mm³ for the RME group and 243.95 ± 473.24 mm³ for the CAT group (P = 0.084), with a moderate effect size (d = 0.57)., Conclusions: RME showed trends favoring better outcomes compared with Invisalign First Phase I treatment across all assessed measures. The only parameter that showed statistically significant differences between the 2 groups was variation in intermolar width at the gingival level, suggesting the occurrence of buccal tipping in patients undergoing Invisalign First Phase I treatment., Trial Registration: The trial was registered at ClinicalTrial.gov (no. NCT04760535)., (Copyright © 2024 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the knowledge and preference of patients treated at a Dental School in Jaraguá do Sul, Brazil, about using aligners and the reasons for choosing this device as a treatment option., Design: A cross-sectional study., Participants: A total of 82 participants aged 18-45 years recruited at a screening clinic., Methods: A questionnaire was completed in person using a tablet with digital forms., Results: Almost half of the participants (49%) knew about aligners; 40% were aged 18-24 years, and 77% were female. When observing the images of the types of orthodontic appliances, the aligners had an acceptance rate of 80%. Among the reasons that led to the preference for choosing aligners, 68% cited aesthetics and 42% comfort., Conclusion: Recently, clear aligners have become a popular choice for orthodontic treatment, particularly among adults. Despite their popularity and effectiveness, many patients still need more information about aligner treatment. Over half of the respondents did not know what orthodontic aligners were. Younger participants had more knowledge about aligners than older participants. Patients still need more knowledge about the types of appliances available for orthodontic treatment. When presented with images of the kinds of devices available, almost 80% of participants showed greater satisfaction with aligners., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: The aim of the present study was to compare the changes in overjet and overbite measurements achieved in adolescent patients following an initial series of Invisalign® aligners (Align Technology, San Jose, California) with those planned by orthodontists via its ClinCheck® digital treatment planning facility., Methods: Data provided by Align regarding patients who had completed an initial series of Invisalign® aligner treatment and were less than 18-years old were assessed in relation to pre-treatment, planned and achieved overjet and overbite measurements. Descriptive statistics, Wilcoxon rank-sum, Mann Whitney calculations were computed., Results: A total of 290 patients satisfied inclusion criteria. The median (interquartile range (IQR)) age was 14.17 (13,15.42) years. The median achieved overjet and overbite changes were less than those planned (p<0.01) with 53.33% of the planned median overjet increase achieved and 52.94% of planned median overjet reduction achieved. Additionally, 58.33% of the planned median overbite increase was achieved and 55.55% of the planned median overbite reduction was achieved. A total of 21.52% patients recorded no change or an increase from pre-treatment to the achieved overjet where reduction was planned, whereas 41.67% recorded no change or a reduction in overjet where increase was planned. A total of 18.72% recorded no change or an increase in overbite where reduction was planned, whereas 20.75% recorded no change or a reduction in overbite where increase was planned., Conclusions: Less than 60% of the planned overjet and overbite changes per patient were achieved. Between 18.72 and 41.67% of patients experienced no change or changes in overjet and overbite in the opposite direction to that planned. This is likely to be clinically significant., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Data Sources: The Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Scopus, Web of Science, Google Scholar, Trip, CINAHL via EBSCO, EMBASE via OVID and ProQuest searched up to June 2023. Any clinical study with parallel arms and matched malocclusion severity should include permanent dentition participants with mild to mild-to-moderate anterior crowding. Participants should have undergone orthodontic treatment with either orthodontic labial fixed appliances or removable clear aligners. Total treatment time (primary outcome), chair time, number of appointments, and emergency visits (secondary outcomes) should also be reported., Study Selection: Two reviewers selected the studies to be considered in two stages. If needed, a third reviewer was included to solve discrepancies. Endnote and Rayyan software supported the process., Data Extraction and Synthesis: The same two reviewers independently extracted the required data from the included studies. If needed, a third reviewer was included to solve discrepancies. Endnote and Rayyan software supported the process., Results: Ten studies were finally included (six RCTs and four non-RCTs). Only one included samples in which teeth were extracted due to crowding. The total included sample was 718 participants (aged 20-29 years). Only one study did not report crowding equivalency between groups., Conclusions: Based on low to very low certainty levels, treatment duration is likely similar, chair time and emergency visits are less frequent, and the number of appointments is increased with clear aligners., (© 2024. The Author(s), under exclusive licence to British Dental Association.)

Purpose: The twin block (TB) is one of the most widely used functional appliances for the correction of class II malocclusions. Align Technology (San Jose, CA, USA) developed the Invisalign® mandibular advancement (MA) that replicates the mechanism of action of a functional appliance. The aim of this study was to compare the changes produced by the TB versus those by MA., Methods: The records of 56 class II patients treated with the TB (TB group: n = 35) or the MA (MA group: n = 21) were compared to a control sample of 15 untreated class II subjects (UC2)., Results: The TB and MA groups showed a significant reduction of the ANB angle, compared to the controls (TB group: -1.5°; MA group: -1.5°; UC2 group: +0.2°). For the Co-Gn values, the TB and MA groups showed significant differences when compared with the UC2 group with an increase of 8.4 mm in TB patients and of 8.3 mm in MA patients. The increase of the distance of Pg to the true vertical line (TVL) was the only measurement where significant differences between the three groups were found with a greater advancement of the soft tissue pogonion in the TB group compared with the MA group and the UC2 group (TB group: +3 mm; MA group: +0.9 mm; UC2 group: -1.6 mm). The angle between the palatal plane and mandibular plane revealed a more relevant reduction in the TB and MA groups. Both appliances were able to reduce overjet and vertical overbite values., Conclusions: Treatment with the MA and TB appliances produced a significant elongation of the mandible with an improvement in sagittal relationship, overjet, and vertical overbite and with good control of the vertical relationship. TB subjects showed a greater advancement of the soft tissue chin., (© 2023. The Author(s).)

Purpose: To evaluate whether clear aligner therapy (CAT) combined with a surgery-early approach can achieve good therapeutic effects in patients with skeletal class III malocclusion., Methods: Thirty consecutive skeletal class III malocclusion cases treated with clear aligners combined with early surgery were selected. Treatment time, lateral cephalograms and American Board of Orthodontics Objective Grading System (ABO-OGS) scores of the treatment models were measured to evaluate the treatment efficiency, facial profile, and occlusion., Results: The results showed that early surgery was achieved after 7.71 months of presurgical orthodontics, on average. ANB decreased by 5.57° (P < 0.001), and STissue N Vert to Pog' decreased by 7.29 mm (P = 0.001), both reaching normal values. The posttreatment ABO-OGS scores were 26.600 on average, meeting its standards., Conclusions: With the assistance of CAT, early surgery can be accomplished in patients with skeletal class III malocclusion, improving their facial profile and achieving functional occlusion., (© 2023. Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Objective: To analyse the biomechanics of molar protraction through clear aligner therapy (CAT) with and without a buccal cantilever., Methods: Models were composed of mandible, lower dentition, periodontal ligaments, attachments, a buccal cantilever, and clear aligner. Four groups were designed: (1) control (aligner only), (2) aligner+buccal cantilever with buccal class II traction, (3) aligner+buccal cantilever with buccal class II and lingual class II tractions, (4) aligner+buccal cantilever with buccal horizontal traction named buccal class I, buccal class II, and lingual class II tractions., Results: CAT alone caused mesial tipping, lingual tipping, and intrusion of mandibular second molar. Adding the buccal cantilever on the mandibular second molar with 100-g buccal class II traction was effective in preventing the mesial tipping of mandibular second molar, but resulted in a greater lingual tipping tendency. Further addition of lingual class II traction prevented aforementioned lingual tipping and bodily protraction was achieved in sagittal dimension, while buccal tipping was present. Bodily protraction without buccolingual tipping was achieved through clear aligner, buccal class II, lingual class II, and buccal class I tractions, and the stress concentrated on the alveolar bone was reduced., Conclusion: CAT produced mesial tipping, lingual tipping, and intrusion of mandibular molar during protraction. The incorporation of the buccal cantilever into the clear aligner improves the biomechanical effect of molar protraction. Bodily molar protraction can be achieved with a judicious combination of buccal class II, lingual class II and buccal class I tractions with clear aligner and buccal cantilever., (Copyright © 2024 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Premature loss of first permanent molars is a common occurrence in clinical practice, leading to abnormal occlusion and inefficient mastication for patients. This case report presented the orthodontic retreatment of a 32-year-old female patient who suffered from premature loss of mandibular bilateral first molars. The mesial tipping of the mandibular second molars led to an occlusal interference, resulting in a clockwise rotation of the lower jaw and an anterior open bite (AOB). We achieved long-distance molar mesialization using clear aligners with Albert cantilever arms. After 42 months of treatment, the patient's occlusion and facial profile significantly improved. The cantilever combined with the cleat aligner treatment has been clinically effective for the protraction of mandibular posterior teeth, extending the field of application of clear aligners., (Copyright © 2024 CEO. Published by Elsevier Masson SAS. All rights reserved.)

ABSTRACT Introduction: Anterior crossbite (AC) is defined as a reverse sagittal relationship between maxillary and mandibular incisors. According to an evidence-based orthodontic triage, the treatment need of AC is indicated if any occlusal interference is forcing the mandible towards a Class III growth pattern. Removable and fixed appliances have been suggested to correct AC. Objective: The present report aims at presenting the benefits of an alternative therapy for the early treatment of anterior crossbite using clear aligners. Methods: Two cases of anterior crossbite corrected using clear aligners in 8-years-old children are presented. Results: In both cases, AC was successfully corrected within 5 months. At the end of the treatment, overjet and overbite were corrected. No major discomfort or speech impairment was noticed by the parents. Conclusions: Due to the perceived shortcomings of alternative approaches, the use of clear aligners for correcting AC in mixed dentition should be considered as a comfortable and well tolerated appliance for young patients.

Introduction: The purpose of this study was to evaluate the therapeutic effect of modified clear Twin Block (CTB) aligner and traditional twin block (TB) appliance from skeletal, dentoalveolar and soft tissue changes in adolescents with skeletal class II malocclusion., Methods: A total of 80 adolescents, included in this study from two medical centres, were distributed into CTB group, TB group and control group based on the treatment they received. Lateral cephalograms at pre-treatment (T1) and post-treatment (T2) were measured by modified Pancherz's cephalometric analysis, and dentoskeletal and soft tissue changes were analysed by independent-sample t-test, paired-sample t-test, ANOVA test and Scheffe's Post Hoc test., Results: Seventy-five adolescents completed the study, including 32 in the CTB group, 32 in the TB group and 11 in the control group. Both CTB and TB treatment showed significant differences in most dentoskeletal and soft tissue measurements. Compared with the control group, improvements were observed in class II molar relationship through significant different in S Vert/Ms-S Vert/Mi in the CTB group (P < .01) and the TB group (P < .001), as well as deep overjet through significant different in S Vert/Is-S Vert/Ii in the CTB group (P < .001) and the TB group (P < .001). Besides, the CTB group also showed less protrusion of lower incisors and resulted in a more significant improvement in profile with fewer adverse effects on speaking, eating and social activities., Conclusions: For adolescents with skeletal class II malocclusion, CTB appliance was as effective as TB on improving dentoskeletal and soft tissue measurements, featuring more reliable teeth control and patient acceptance., (© 2024 John Wiley & Sons A/S.)

Objective: To compare the anterior crowding correction after sequential use of the first 5 aligners between two aligner exchange protocols (7 and 14 days) in mature adult patients., Materials and Methods: Thirty-six patients over 35 years who received orthodontic treatment with Invisalign® were randomly allocated to two different aligner replacement sequence protocols: Group 1: exchange every 7 days (n = 18); and Group 2: exchange every 14 days (n = 18). All patients were scanned with iTero Element 5D® (Align Technology) in two treatment times: at pre-treatment (T1) and after using the first five aligners (T2). Little's Irregularity Index (LII) and arch widths were evaluated with OrthoCAD software. Intra and intergroup comparisons were performed with the dependent and independent t-tests. The results were considered significant for P < .05., Results: Thirty-five patients completed the study. Both groups' maxillary and mandibular Irregularity Indexesi were significantly lower at T2. There was no significant difference in inter-canine, inter-premolar, and intermolar distances. G2 (14 days) presented a greater decrease in mandibular irregularity than G1 (7 days)., Conclusion: Both exchange protocols (7 and 14 days) effectively correct anterior crowding in the initial phase of orthodontic treatment with aligners in mature adult patients. However, the 14-day exchange protocol provided a greater correction in mandibular anterior crowding in the evaluated period than the 7-day exchange protocol., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: The use of clear aligners is becoming more common for aesthetic orthodontic treatment, but there are still concerns about how they affect mastication biomechanics in the short and long term. The clear aligners treatment (CAT) mechanism changes the position of the mandible and maxilla, especially impacting the masseter muscle. Surface electromyography (sEMG) proves to be a useful method to evaluate masticatory muscle activity (MMA)., Objectives: To analyze the effect of clear aligners treatment on alterations in masticatory muscles (masseter, temporalis) using surface electromyography., Search Methods: Five databases (PubMed, Web of Science, SCOPUS, Cochrane Library, and Google Scholar) were searched up to March 2024., Selection Criteria: Studies in which MMA was evaluated after the installation of orthodontic clear aligners., Data Collection and Analysis: Screening, data extraction, and quality assessments were performed by four investigators independently. The data, which evaluated temporalis and masseter muscle characteristics during CAT using surface electromyography, was extracted, and the quality of the studies was evaluated. The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS)., Results: Six studies (two prospective cohort studies, three observational longitudinal studies, and one observational longitudinal case-control study) with low and moderate risk of bias were included in the qualitative synthesis. Six of these were also included in the meta-analysis. Our study investigated the dynamics of masseter and temporalis muscle activity during CAT. The results show that during maximal voluntary clenching, the masseter muscle demonstrated a significant initial increase (P < .05) followed by a subsequent non-significant decrease. It also showed that submaximal voluntary clenching consistently exhibited a significant reduction in muscle activity throughout the study period (P < .01). Assessment of muscle activity at the mandibular resting position revealed a variety of responses, with some participants showing a significant increase while others exhibited non-significant changes (P < .05, P > .05, respectively). However, the meta-analysis showed a non-significant difference in measuring masseter and temporalis muscles activity during CAT., Conclusions: Based on existing evidence, it is reasonable to conclude that CAT affected MMA. During maximal voluntary clenching, masseter muscle activity initially increased but later decreased, while temporalis muscle activity showed mixed results. Submaximal voluntary clenching revealed a consistent decrease in muscle activity over time. Mandibular resting position assessments showed both increases and no significant changes in muscle activity. However, the existing literature is insufficient to draw concrete conclusions; therefore, well-conducted further research is needed to confirm this statement., Registration: This systematic review and meta-analysis were registered in the International Prospective Register of Systematic Reviews (PROSPERO CRD42024522231)., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Orthodontic Society.)

Objective: This study compared clinical outcomes between aligners and fixed appliances in class II adolescent patients., Materials and Methods: Records of 31 aligners and 35 fixed class II patients, aged 13.5 ± 1.6 years were compared. Class II elastics was the mechanism employed for correcting the malocclusion. DI scores were used to compare initial complexity, and the PAR index scores were used to compare the clinical outcomes. Data on demographics, treatment and finishing durations, number of visits and refinements, duration of class II correction, and changes in the IMPA were collected., Results: The mean pre-, post-treatment, and overall reduction in PAR index scores between the groups were not significantly different (P > 0.05). The clear aligners group had significantly shorter treatment duration (20.0 ± 11.6 months) than the fixed group (27.4 ± 9.1 months) (P < 0.001). The number of visits for the aligners' group was significantly less (12.7 ± 6.2) than in the fixed group (17.8 ± 5.8) (P < 0.001). Duration for class II correction was significantly shorter for clear aligners (13.3 ± 10.0 months) compared to the fixed group (17.4 ± 9.0 months) (P = 0.026). A smaller post-treatment change in IMPA (2 ± 6°) was detected in the aligners group compared to the fixed group (5 ± 6°) (P < 0.05)., Conclusions: Treatment outcomes for aligners in class II adolescent patients were comparable to those achieved in fixed appliances. Shorter treatment and class II correction durations, fewer visits, and better control for the IMPA were noticed in the aligners' group., Clinical Relevance: Treating class II adolescent patients with aligners seems promising and demands shorter treatment time and fewer visits., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In orthodontic treatment of patients during the mixed dentition period, arch expansion and opening deep overbite are one of the objectives to achieve proper alignment of the teeth and correction of sagittal and vertical discrepancies. However, the expected outcomes of most therapeutic regimens are not clear, making it impossible to standardize early treatment effects. Therefore, this study was designed to evaluate the impact of the Invisalign® First System on the dental arch circumference and incisor inclination in patients during the mixed dentition period. A total of 21 children during the mixed dentition period (10 females and 11 males, with an average age of 8.76 years) were included in this study. The patients received non-extraction treatment through Invisalign® First System clear aligners, and no other auxiliary devices were used except Invisalign® accessories. Subsequently, the cooperation degree of patients during treatment and the oral measurement parameters at the beginning (T1) and the end (T2) of treatment were collected. All patients showed moderate/good cooperation degree during treatment. Besides, horizontal width of the maxillary first molar increased significantly; the designed arch expansion was 4.1 mm (±1.4 mm), while the actual arch expansion was 3.0 mm (±1.7 mm). Furthermore, the torque expression rate of upper anterior teeth reached 56.53%. Invisalign® First System clear aligners can effectively correct the teeth of patients during the mixed dentition period, widen the circumference of dental arch, and control the torque of incisors., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)