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Background Class II malocclusion, particularly class II division 1, poses a significant orthodontic challenge with implications for both aesthetics and health. This study aimed to explore the impact of twin-block (TB) combined with maxillary expansion treatment (TB-ME) on upper airway dimensions and inflammatory profiles in adolescents with skeletal Class II Division 1 malocclusion in adolescent. Methods Ninety-two eligible patients were randomly assigned to two groups: TB-ME treatment and traditional McLaughlin Bennett Trevisi (MBT) straight-wire orthodontic treatment (Control). Cephalometric lateral X-ray scans were conducted before and after treatment to assess skeletal changes, including SNA, ANB, and SNB angles, which are essential to assess the anteroposterior relationships of the maxilla and mandible to the cranial base. We also measured the upper airway volumes and areas. Concentrations of inflammatory factors including intercellular adhesion molecule 1 (ICAM-1), matrix metallopeptidase 2 (MMP2), and interleukin 8 (IL-8) of gingival crevicular fluid analysis (GCF) were detected by enzyme-linked immunosorbent assay. Results TB-ME treatment induced significant improvement in cephalometric parameters, including a decrease in SNA and ANB angles and an increase in SNB angle. Upper airway volumes and areas increased significantly in both groups, with TB-ME showing greater improvements. GCF analysis revealed a reduction in ICAM-1, MMP2, and IL-8 concentrations in the TB-ME group compared to the Control group. Conclusions TB-ME treatment demonstrates multifaceted improvements in skeletal malocclusion, upper airway dimensions, and inflammatory profiles in adolescents with class II division 1 malocclusion, showing the promise of TB-ME in addressing the complexities associated with class II malocclusion.

Background Angle Class II malocclusion typically presents with overbite, distal molar relationship, and crowding of the upper anterior teeth. The distal movement of the maxillary molars is considered an optimal treatment strategy, as it can circumvent the need for orthodontic extraction. Clear aligners are currently used for molar distalization. However, this approach is not without its limitations, including the loss of anterior tooth anchorage and an extended treatment duration. To address these issues, this study introduces a novel molar distalization appliance. A clinical randomized controlled trial will compare the efficacy of this appliance with clear aligners, specifically assessing differences in the rate of tooth movement. Methods This study will recruit 30 patients aged 18–35 with Angle Class II malocclusion, characterized by distal molar relationship, mild to moderate crowding, or protrusion of anterior teeth. Patients will be randomly divided into two groups: the experimental group using a novel molar distalization appliance, and the control group using clear aligners for molar distalization. Both groups will use orthodontic miniscrews as an anchorage, with elastic traction for molar distalization. Cone-beam CT and digital dental models will be collected before orthodontic intervention and after molar distalization for all samples. This study will register pre- and post-treatment images using maxillary bone structures and then analyze three-dimensional tooth movement. The study will further calculate the distance of molar distal movement per unit time as the tooth movement rate and compare whether there is a difference between the experimental and control groups. Discussion This randomized controlled trial will serve as evidence that the novel molar distalization device, compared to clear aligners, whether offers advantages such as shorter treatment duration and superior control of tooth movement. It can provide a novel method for orthodontic clinical treatment of patients with Angle Class II malocclusion. Trial registration ClinicalTrials.gov ChiCTR2300069122. Registered on 7 March 2023.

Trial design Parallel. Objective To compare skeletally anchored Carriere Motion appliance (CMA) for distalization of the maxillary buccal segment vs. Essix anchored CMA. Methods Thirty-two class II malocclusion patients were randomly allocated into two equal groups. One group was treated with infrazygomatic (IZC) miniscrew- anchored CMA (IZCG) and the other group treated with Essix retainer- anchored CMA (EXG). Two lateral cephalograms and two digital models for upper and lower arches were taken for each patient: immediately before intervention and after distalization had been completed. Results Distalization period was not significantly different between the two groups. In contrast to EXG, IZCG showed insignificant difference in ANB, lower incisor proclination, and mesial movement of the lower first molar. There was significant rotation with distal movement of maxillary canine and first molar in both groups. Conclusion IZC anchored CMA could eliminate the side effects of class II elastics regarding lower incisor proclination, mesial movement lower molars with a more significant amount of distalization of the maxillary buccal segment but with significant molar rotation. Trial registration The ClinicalTrials.gov Protocol Registration and Results System (PRS) has this RCT registered as (NCT05499221) on 12/08/2022.

This prospective randomized clinical trial aimed to evaluate the effect of low-level laser therapy on tooth movement during Class II intermaxillary elastics treatment. Forty-two patients with Class II malocclusion were included, and their maxillary quadrants were allocated into two groups: treatment with an active diode laser and a placebo group. In each group, the time taken to obtain Class I occlusion after 6 months, rate of movement, total displacement of the maxillary canine to Class I occlusion and pain were recorded. The time to reach Class I occlusion in the active laser group (2.46 ± 2.1 months) was not significantly different from that in the placebo group (2.48 ± 2.0 months) ( p  = 0.938). Interestingly, the total distance of movement on the active laser side (2.27 ± 1.5 mm) was significantly greater than that on the placebo side (1.64 ± 1.3 mm) ( p  = 0.009). The pain levels on days 1, 2 and 3 were not significantly different between the laser and placebo sections. The rate of distance change toward Class I occlusion in the laser group (1.1 ± 0.7 mm/month) was significantly higher than that in the placebo group (0.74 ± 0.6 mm/month) ( p  = 0.037). Low-level laser therapy (970 nm) did not reduce the time needed to obtain Class I occlusion, but a significant acceleration in tooth movement was observed in the irradiated group. Trial registration: NCT02181439. Registered 04 July 2014— https://www.clinicaltrials.gov/ct2/results?term=cinelaser .

Digital technologies have transformed orthodontics by enabling precise three-dimensional (3D) assessment of treatment outcomes; however, the effects of extraction versus non-extraction strategies on palatal morphology in Class II malocclusions remain underexplored. This study quantified segmental palatal volume and surface changes, along with skeletal–dentoalveolar outcomes, using digital model analysis integrated with cephalometrics. Records of 69 post-pubertal patients treated with fixed appliances (Class II, n = 34; Class I controls, n = 35) were retrospectively analyzed, each subdivided into extraction and non-extraction protocols. Maxillary casts were scanned with Sirona inEos X5 and segmented in Materialise 3-Matic to compute palatal volume and surface area, while cephalometric variables were derived from lateral radiographs (Dolphin Imaging). Group comparisons were performed using non-parametric tests ( p  < 0.05). Multivariable regression analyses were conducted to identify dentoalveolar predictors of palatal remodeling. Intra-examiner repeatability was excellent, as indicated by a high intraclass correlation coefficient (ICC ≥ 0.90). Skeletal changes were minimal and comparable across groups. Dentoalveolar findings demonstrated significant maxillary incisor protrusion in non-extraction protocols and retrusion in extraction protocols ( p  < 0.05). Anterior palatal volume and surface area increased across all groups. Overall, measurable differences in total palatal volume and surface area were observed between extraction and non-extraction treatment strategies. Regression analyses indicated that sagittal dentoalveolar displacement was associated with palatal remodeling, whereas angular and vertical dental variables showed limited independent influence. Extraction and non-extraction treatment protocols were associated with measurable differences in three-dimensional palatal volume and surface area, reflecting distinct dentoalveolar and palatal remodeling patterns between treatment strategies.

This retrospective observational study compared the effects of traditional Anterior Repositioning Splint (ARS) and digital ARS on the upper airway of patients with skeletal Class II malocclusion and temporomandibular joint degenerative joint disease. A total of 110 patients were included and divided into two groups: the traditional ARS group (55 cases) and the digital ARS group (55 cases). Dolphin Image 11.95 software was used to measure the CBCT of the temporomandibular joint before and after treatment, and upper airway-related indicators were analyzed. Additionally, patient satisfaction and chairside adjustment time were assessed. The results showed that in the traditional group, the oropharyngeal volume and the total oronasopharyngeal volume significantly increased after treatment ( P  < 0.05), while there was no statistical difference in the nasopharyngeal volume and the minimum oropharyngeal cross-sectional area. In the digital group, the nasopharyngeal volume significantly increased after treatment ( P  < 0.05), and the other three indicators increased more significantly ( P  < 0.01). Intergroup comparisons of changes in upper airway indicators, only the minimum cross-sectional area, the digital group showed a significantly greater improvement than the traditional group (95%CI: 2.15–62.59; P  = 0.023). There was no difference in the base tooth discomfort score between the two groups, but there were statistical differences in the degree of speech impact, foreign body sensation, appearance impact, opposing tooth discomfort, total satisfaction score, and chairside adjustment time ( P  < 0.05). The conclusion is that the digital anterior repositioning anatomical splint is superior to the traditional splint in terms of improvement effects on the upper airway, efficiency of clinical operations and patient satisfaction. Clinical trial number: KS20241029001.

Background Several appliances have been used for correction of developing skeletal Class II, including different myofunctional appliances as Twin block (TB)as well as the new pre-fabricated Myobrace (MB) appliance. However, the effects of these devices on the pharyngeal airways have not been compared in the literature. Thus, the aim of this study was to compare the effects of two Class II correction appliances; TB and MB on the sagittal pharyngeal airway dimension (SPAD), including the nasopharyngeal airway area (NPAA), the oropharyngeal airway area (OPAA), and the laryngopharyngeal airway area (LPAA). Methods This is a two parallel arms randomized comparative clinical trial. Twenty-six children of 9–12 years with Skeletal Class II malocclusion due to mandibular deficiency and normal maxillary growth as confirmed by lateral cephalometric X-ray readings (ANB angle > 4° and SNB angle < 78) and Cervical vertebral maturational index (CVMI) 1 or 2 were randomly assigned into two equal groups. Group I: TB, Group II: MB (prefabricated functional appliance, Myofunctional Research Co., Australia). Lateral cephalograms were taken for all patients in both groups before treatment (T1) and after treatment (6 months later) (T2). The primary aim was to assess pre and post treatment changes in the SPAD in each group, and compare between the two study groups. The secondary aim was to evaluate the sagittal skeletal measurements such as the SNA, SNB, ANB, Wits appraisal, as well as vertical skeletal measurements represented by the Frankfurt-mandibular plane angle (FMA) measured pre- and post-treatment. The independent samples t-test was used to compare the two study groups, and the mean difference and 95% confidence intervals (CI) were computed. The paired samples t-test was used to compare various parameters between T1 and T2 within each group. The cutoff for significance was p -value < 0.05. Data were analyzed using IBM SPSS for Windows (Version 26.0). Results By Comparing changes in airway measurements within each group, it was found that NPAA, OPAA, and LPAA increased significantly after treatment within each group of MB and TB. TB group showed significantly higher mean difference (T2-T1) in both NPAA and OPAA than MB group with 28.39 (± 56.75) and 40.46 (± 52.16) respectively. The increase in LPAA values was not statistically significant at (T2-T1) between both groups. Regarding skeletal changes, there was a significant increase in the SNB values between T1 and T2 within each group with 2.82 (± 3.32) for MB group and 3.79 (± 3.06) for TB group Moreover, there was a significant decrease in the ANB values between T1 and T2 within each group by 2.42 (± 2.70) for MB group and 3.06 (± 1.14) for TB group. Similarly, there was a significant decrease in the ANB values between T1 and T2 within each group by -2.13 (± 0.62) for MB group and − 2.46 (± 0.72) for TB group. No significant differences were found between both groups in SNA, SNB, ANB and Wits appraisal at p  = 0.06, p  = 0.45, p  = 0.43 and p  = 0.22 respectively. FMA did not show significant difference between T1 and T2 within each group, nor showed a significant mean difference between both groups at T2-T1. Conclusions TB was more effective than MB in improving the upper (NPAA) and middle (OPAA) airways, while no difference was found regarding the lower airway (LPAA). Both TB and MB reduced the severity of developing skeletal class II due to mandibular retrognathism by forward posturing of the mandible. Thus, patients with airway problems would benefit more from TB than MB.

Background Temporomandibular joint (TMJ) disc repositioning through open suturing (OSu) is a new disc repositioning method. Its result for adolescents with condylar resorption and dentofacial deformities combined with and without postoperative occlusal splints (POS) has not been well studied. Objective This study was to evaluate and compare the effects of OSu with and without POS in the treatment of TMJ anterior disc displacement without reduction (ADDwoR) in adolescent skeletal Class II malocclusion. Methods A total of 60 adolescents with bilateral ADDwoR were enrolled in this study. They were randomly allocated into two groups: OSu with and without POS. Magnetic resonance imaging (MRI) and lateral cephalometric radiographs were used to measure changes in condylar height and the degree of skeletal Class II malocclusion from before operation and at 12 months postoperatively. Changes in these indicators were compared within and between the two groups. Results After OSu, both groups exhibited significant improvements in condylar height and occlusion at the end of 12 months follow-up ( P  < 0.05). The group of OSu with POS had significantly more new bone formation (2.83 ± 0.75 mm vs. 1.42 ± 0.81 mm, P  < 0.001) and improvement in dentofacial deformity than the group of OSu only ( P  < 0.05). The new bone height was significantly correlated with POS ( P  < 0.001), the changes of SNB ( P  = 0.018), overjet ( P  = 0.012), and Wits appraisal ( P  < 0.001). Conclusion These findings indicated that OSu can effectively stimulate condylar regeneration and improve skeletal Class II malocclusion in adolescents with bilateral ADDwoR. The results are better when combined with POS. Trial registration This trial was prospectively registered on the chictr.org.cn registry with ID: ChiCTR1900021821 on 11/03/2019

ABSTRACT Introduction: Patients with Class II, division 1 malocclusion generally seek treatment to improve facial esthetics. Therefore, the orthodontist needs to know the changes in the soft profile produced by functional appliances. Objective: This study evaluated the soft tissue profile changes in patients treated during the peak of the pubertal growth spurt. Methods: Thirty selected patients were randomized into three treatment groups: Twin Block (TB), Herbst with dental anchorage (HDA), and Herbst with skeletal anchorage (HSA). All patients had computed tomographic images: pretreatment (T1) and after 12 months of active treatment (T2). Twenty-four soft tissue cephalometric measures were analyzed. The normality of all data was assessed by the Shapiro-Wilk test. Intragroup comparisons were analyzed using the t-paired test; the inter-group comparisons were determined through ANOVA and the post-hoc Tukey test. Results: At T1, no significant differences were observed between groups. At T2, in the intragroup comparison, facial soft tissue changes were statistically significant in the three groups for the lower lip, sulcus inferioris, facial soft tissue convexity in HDA group and TB group, and H angle in HDA group and HSA group, and soft tissue pogonium in TB group. In the inter-group comparison, no statistically significant differences were observed. Conclusion: It can be concluded that there were significant changes in soft tissue measurements that benefited Class II, division 1 patient’s facial profile treated with the functional appliances Twin Block, Herbst, and Herbst with skeletal anchorage. Nevertheless, no significant differences were detected among the effects obtained by the three treatment protocols. RESUMO Introdução: Pacientes portadores de má oclusão de Classe II, divisão 1, geralmente buscam tratamento para obter melhora da estética facial. Logo, é essencial que o ortodontista conheça as alterações do perfil mole associadas a uma das principais modalidades de tratamento dessa má oclusão: os aparelhos propulsores mandibulares. Objetivo: O presente estudo avaliou as alterações nos tecidos moles do perfil facial em pacientes tratados durante o pico do surto de crescimento puberal com aparelhos propulsores mandibulares removível, fixo ou fixo associado à ancoragem esquelética. Métodos: Trinta pacientes foram randomizados em três grupos: Twin Block (TB), Herbst com ancoragem dentária (HAD) e Herbst com ancoragem esquelética (HAE). Os pacientes realizaram tomografias computadorizadas pré-tratamento (T1) e após 12 meses de tratamento (T2). Foram analisadas 24 medidas cefalométricas em tecidos moles. A normalidade dos dados foi avaliada pelo teste de Shapiro-Wilk, as comparações intragrupo foram feitas por meio do teste t pareado; as comparações intergrupo, feitas com ANOVA e o teste post-hoc de Tukey. Resultados: Em T1, não foram observadas diferenças significativas entre os grupos, confirmando a homogeneidade da amostra. Na comparação intragrupos, foram detectadas alterações estatisticamente significativas nos três grupos, na convexidade facial de tecido mole, sulcus inferioris e pogônio mole; e na comparação intergrupo não foram observadas diferenças estatisticamente significativas. Conclusão: Após o tratamento com os aparelhos ortopédicos, foram detectadas alterações significativas que beneficiaram os tecidos moles da face de pacientes Classe II, divisão 1. Porém, não foram detectadas diferenças significativas nos efeitos obtidos entre os três tipos de aparelhos.

ABSTRACT Objective: The aim of this study was to assess the perception regarding the attractiveness of the face in patients with skeletal Class II and simulations of possible treatments for this condition. Methods: Dental scans, face scans and cone beam computed tomography (CBCT) of a male patient were used. These images were grouped in a software, where the original file was edited in order to achieve a profile that had the most pronounced skeletal and dental Class II (division 1) features, as well as the different proposed treatments: Compensatory orthodontics with extraction of the maxillary first premolars; Compensatory orthodontics associated with surgical advancement of the chin; and Orthodontics associated with combined orthognathic surgery of the maxilla, mandible and counterclockwise rotation of the occlusal plane. These simulations were presented in the form of videos and accompanied by a questionnaire regarding the attractiveness. Results: The videos were analyzed by 275 evaluators: 109 orthodontists, 91 oral and maxillofacial surgeons and 165 laypersons. The collected data were submitted to analysis of variance (ANOVA) and Student’s t tests, with a significance level of 95%. Individuals with higher levels of education were more rigorous in their aesthetic evaluation, but the most attractive face for all groups was achieved by orthodontic preparation associated with combined orthognathic surgery, while the least attractive was skeletal Class II without treatment. Conclusions: This study indicate that the face resulting from a skeletal Class II is aesthetically unfavorable and the treatments generate better aesthetic results, especially the orthodontic preparation associated with combined orthognathic surgery. RESUMO Objetivo: O objetivo deste estudo foi avaliar a percepção da atratividade facial em pacientes com Classe II esquelética e simular possíveis tratamentos para essa condição. Métodos: Foram utilizados escaneamentos dentários, escaneamentos faciais e tomografia computadorizada de feixe cônico (TCFC) de um paciente do sexo masculino. Essas imagens foram agrupadas em um software, onde o arquivo original foi editado para obter um perfil que apresentasse as características esqueléticas e dentárias de Classe II (1ª divisão) mais pronunciadas, bem como os diferentes tratamentos propostos: Ortodontia compensatória com extração dos primeiros pré-molares superiores; Ortodontia compensatória associada ao avanço cirúrgico do mento e Ortodontia associada à cirurgia ortognática combinada de maxila, mandíbula e rotação anti-horária do plano oclusal. Essas simulações foram apresentadas em forma de vídeos e acompanhadas de um questionário sobre atratividade. Resultados: Os vídeos foram analisados por 275 avaliadores: 109 ortodontistas, 91 cirurgiões bucomaxilofaciais e 165 leigos. Os dados coletados foram submetidos aos testes de Análise de Variância (ANOVA) e t de Student, com nível de significância de 95%. Indivíduos com maior escolaridade são mais rigorosos em sua avaliação estética, mas a face mais atraente para todos os grupos foi alcançada pelo preparo ortodôntico associado à cirurgia ortognática combinada, enquanto a menos atraente foi a Classe II esquelética sem tratamento. Conclusões: Este estudo indica que a face resultante de uma Classe II esquelética é esteticamente desfavorável e os tratamentos geram melhores resultados estéticos, especialmente o preparo ortodôntico associado à cirurgia ortognática combinada.