Treatment effects of removable functional appliances in patients with Class II malocclusion: a systematic review and meta-analysis

Precision wings treating skeletal class II in growing patients: a systematic review and meta-analysis

BACKGROUND

Skeletal Class II malocclusion, often associated with mandibular deficiency, is commonly treated with functional appliances. Precision Wings are a functional appliance that provides an alternative approach by combining mandibular advancement with dental alignment.

OBJECTIVE

This systematic review aimed to evaluate the effectiveness of Precision Wings in treating skeletal Class II malocclusion in growing patients.

ELIGIBILITY CRITERIA

Studies assessing the correction of skeletal Class II malocclusion in growing patients treated with Precision Wings were selected according to the PICOS strategy. The PRISMA guidelines were followed.

INFORMATION SOURCES

Unrestricted electronic searches were conducted across seven databases up to February 2025.

RISK OF BIAS AND SYNTHESIS OF RESULTS

The ROBINS-I tool was used to assess the risk of bias (RoB) in non-randomized studies. A random-effects meta-analysis was performed, and the certainty of the evidence was evaluated using the GRADE approach.

RESULTS

Seven studies were included, and data were extracted. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects meta-analysis. The findings suggest that Precision Wings may be effective in treating skeletal Class II malocclusion in growing patients through both dental and skeletal changes. Regarding skeletal effects, sagittal changes were limited to the mandible and were of small magnitude, with a reduction in ANB° (MD = -0.81; 95% CI: -1.04 to -0.58; p < 0.001) occurring exclusively due to an increase in SNB° (MD = 0.55; 95% CI: 0.11 to 0.98; p = 0.01), while no significant changes were observed in SNA° (MD = -0.02; 95% CI: -0.42 to 0.38; p = 0.91). The included studies did not report significant vertical effects. Meta-analyses comparing Precision Wings with other functional appliances were not feasible due to the small number of studies evaluating each comparison and the substantial clinical and methodological heterogeneity across the included studies.

CONCLUSION

Although the available scientific evidence on this topic is limited, treatment with Precision Wings appears to offer minimal clinical improvement in mandibular growth for the correction of skeletal Class II malocclusion. To obtain more conclusive findings, future research should prioritize well-structured randomized clinical trials with standardized treatment protocols, extended follow-ups, and consistent cephalometric assessment methods.

Coefficient of efficiency and effectiveness of functional appliances in class II malocclusion treatment : A systematic review

OBJECTIVE

To evaluate the coefficient of efficiency and effectiveness of removable and fixed functional appliances in class II malocclusion treatment.

DATA SOURCES

Search of studies in five databases (Medline via PubMed, Cochrane library, LILACS, SCOPUS, and SciELO) that measured mandibular skeletal changes following functional therapy was conducted until 15 April 2024.

STUDY SELECTION

All study designs including randomized and controlled clinical trials (RCT), prospective and retrospective studies were included. Data were extracted independently by two authors from studies that fulfilled the inclusion criteria. Mandibular length changes of class II patients treated with functional appliances were collated for each retrieved study.

RESULTS

From 6796 potentially eligible studies, 90 were considered for this systematic review. Four were RCTs which were graded with the Cochrane risk of bias tool. Three were assessed as having low and one as having moderate risk of bias. The other 86 studies were graded with the modified Downs and Black tool which revealed that 47 showed low, 38 low/moderate, and 1 a moderate risk of bias. The most commonly assessed appliances were the Twin Block which was used on 783 patients, the Frankel appliance on 573, the Herbst appliance on 530, the Activator on 449, the Forsus appliance on 394, the MARA appliance on 202, and the Bionator on 133, for a total of 3064 treated patients.

CONCLUSION

This systematic review provides conclusive evidence that the Twin Block appliance demonstrated the highest coefficient of efficiency among all the evaluated appliances (0.46 mm/month), while the Forsus fatigue resistant device (FFRD) had the highest coefficient of efficiency among the fixed functional appliances (0.41 mm/month).

Interceptive Treatment of Class II Malocclusion in Pediatric Patients Using Clear Aligner Mandibular Advancement: A Systematic Review Following PRISMA Guidelines

While conventional functional appliances have been widely used to manage Class II malocclusion in growing pediatric patients, advancements in interceptive treatments have introduced aligner mandibular advancement as a modern and aesthetic alternative. Despite its increasing popularity, the effectiveness of aligner mandibular advancement has not been systematically evaluated. This systematic review aimed to evaluate the effectiveness of interceptive aligner mandibular advancement in the treatment of Class II malocclusion in pediatric patients, focusing on skeletal, dental, and soft tissue outcomes. This review adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses or PRISMA guidelines. Studies evaluating pediatric patients with Class II malocclusion treated with aligner mandibular advancement were included. The databases searched included PubMed, Cochrane Library, Web of Science, Embase, and Scopus, with searches conducted up to November 30, 2024, to identify relevant articles addressing the PICOS framework (Population, Intervention, Comparison, Outcome, and Study design). The focus questions were: How effective is clear aligner mandibular advancement in the treatment of pediatric patients with Class II malocclusion? What are its associated treatment outcomes? The ROBINS-I tool was used to assess the risk of bias. Data were synthesized narratively due to heterogeneity in study designs and outcomes. Nine studies with 426 participants were included, conducted between 2021 and 2024. Seven studies adopted retrospective designs, one study used a prospective design, and one relied on a survey-based design. Aligner mandibular advancement demonstrated effectiveness in reducing overjet and ANB while maintaining lower incisor inclination compared to conventional functional appliances. Soft tissue improvements were also reported. Patients favored aligner mandibular advancement over conventional functional appliances for its superior comfort, better aesthetics, and less breakage. However, most studies were retrospective, and the lack of randomized controlled trials limited the strength of the evidence. Clear aligner mandibular advancement appears to be an effective approach for managing Class II malocclusions in growing pediatric patients, offering the distinct advantage of maintaining lower incisor inclination compared to other conventional functional appliances. However, the evidence remains limited due to methodological constraints, including the lack of randomized controlled trials, small sample sizes, and inconsistencies in study designs.

Skeletal and dental effects of skeletally anchored forsus fatigue resistant devices during class II malocclusion treatment: A meta-analysis and systematic review

OBJECTIVE

To evaluate and compare the skeletal and dental treatment effects of Class II malocclusion cases using skeletally anchored Forsus (miniscrew-anchored FRD or miniplate-anchored FRD), with conventional Forsus FRD.

MATERIALS AND METHODS

Unrestricted electronic search of six databases and additional manual searches were performed up to July 2023. Randomized controlled trials having one treatment arm with skeletal anchored Forsus FRD in treatment of Class II malocclusion and another matched treatment group treated with conventional Forsus FRD were included in this review. Risk of bias assessment was performed using Cochrane's Risk of Bias Tool. No restrictions were set concerning treatment duration, or the cephalometric analysis used. Skeletal and dentoalveolar outcomes data were extracted by two authors independently.

RESULTS

Three studies using miniscrews as means of skeletal anchorage were evaluated and qualified for the final review and meta-analysis. Three other studies using miniplates were considered in the systematic review but were not qualified for a meta-analysis. The data gathered from the miniscrews anchored FRD papers included a total of 93 Class II patients (46 treated with miniscrew-anchored Forsus FRD, 47 treated with conventional Forsus FRD). The meta-analysis showed a statistically significant reduction in the SNA angle in favor of miniscrew-anchored Forsus FRD (mean difference: -0.26, CI: -0.50 to -0.02), a nonsignificant difference in the SNB (mean difference: 0.17, CI: -0.06 to 0.39), a statistically significant increase in the SN-MP angle in favor of miniscrew-anchored Forsus FRD (mean difference: 0.53, CI: 0.06-1.00)-a statistically significant reduction in the L1-MP angle in favor of miniscrew-anchored Forsus FRD (mean difference: -2.12, CI: -4.96 to -2.12). Data from miniplate-anchored FRD included 31 Class II patients treated with mini plate anchored FRD. Although meta-analysis was not applicable to these studies, lower incisor inclination was observed to be less.

CONCLUSIONS

Based on the existing evidence, the use of skeletal anchorage could not enhance forward mandibular growth. However, miniscrew-anchored Forsus FRD could minimize mandibular incisor protrusion while miniplates could even retract the mandibular incisor position with a headgear effect on the maxilla.

Perception of facial esthetics and cephalometric correlations in Class II patients: a comparison between two-phase and one-phase treatments

An effective orthodontic treatment should not only aim for satisfactory occlusal outcomes but also consider its impact on facial esthetics. The study aims to evaluate and compare the perception of profile esthetics of skeletal Class II patients treated with two orthodontic modalities: (1) Two-phase approach involving functional appliances followed by fixed appliances with premolar extractions, or (2) One-phase approach using fixed appliances with premolar extractions. Additionally, the study aims to evaluate the correlation between the perceived esthetics and the corresponding cephalometric measurements. The study included 40 skeletal Class II adolescents who underwent either two-phase (n = 20, mean age = 12.38 ± 1.18) or one-phase (n = 20, mean age = 12.53 ± 0.79) orthodontic treatments. Eighty profile silhouettes (pre- and post-treatment) were assessed by 64 raters, including 23 orthodontists, 21 general dental practitioners, and 20 laypersons. The raters used a visual analog scale (VAS) to access profiles, upper and lower lips, and chin esthetics. At pre-treatment, all three groups of raters gave significantly lower scores to the profile silhouettes of the two-phase group compared to the one-phase group (P < 0.01); however, after treatment, they rated the two-phase group significantly higher (P ≤ 0.001). The two-phase group exhibited greater improvements in profile and upper and lower lip esthetics as perceived by all raters (P ≤ 0.001). Furthermore, cephalometric results revealed greater reductions in SNA, ANB, Wits appraisal, and G'-Sn-Pog' in the two-phase group compared to the one-phase group (P < 0.05). Five cephalometric parameters (SNB, SNPog, overjet, overbite, and UL-SnPog') demonstrated significant correlations with VAS scores given by orthodontists (P < 0.05). In conclusion, the two-phase group showed greater subjective and objective improvements in facial esthetics than the one-phase group. Additionally, the anteroposterior mandibular position and upper lip protrusion may be the primary cephalometric parameters correlated with subjective facial profile perceptions.

Long-term (≥ 15 years) outcome quality after Class II:1 bionator or Herbst multibracket appliance treatment : A comparison

PURPOSE

To compare the long-term outcome quality (≥ 15 years) of Class II:1 treatment using either a bionator (BIO) or a Herbst-multibracket appliance (HMB).

METHODS

Patients who underwent functional treatment during the ideal treatment period for the respective approach (prepuberty vs. peak/postpeak) were assessed. Inclusion criteria were overjet ≥ 4 mm, skeletal Class II and availability of study casts from before, after and ≥ 15 years after treatment. The study casts were assessed using the Peer Assessment Rating (PAR) index and standard orthodontic cast measurements.

RESULTS

During treatment, PAR score, overjet and sagittal occlusal relationship improved significantly in all groups. Long-term, there was a significant increase of incisor irregularity in the upper (HMB) and lower (BIO) arch and a significant decrease of lower arch width 3 - 3 (BIO). PAR score, overjet, and sagittal occlusal relationship remained stable long-term. Intergroup comparisons revealed significant differences between the BIO and HMB groups in terms of lower arch width (6 - 6), upper and lower arch width (3 + 3/3 - 3) as well as sagittal molar relationship.

CONCLUSIONS

The achieved improvement in PAR score, overjet, and sagittal occlusion remained comparably stable long-term in all groups. The long-term changes are probably a consequence of natural aging.

Exploring publications in 3 major orthodontic journals: A comparative bibliometric analysis of two 10-year periods (2002-2011 and 2012-2021)

INTRODUCTION

This study aimed to perform a bibliometric analysis examining contributing countries and collaborative networks, authors and collaborative relationships, the performance of the institutions, and cocited journals and references in 3 major orthodontic journals (American Journal of Orthodontics and Dentofacial Orthopedics, European Journal of Orthodontics, and Angle Orthodontist) over two 10-year periods (2002-2011 and 2012-2021).

METHODS

In this study, 4432 publications in the first decade and 4012 publications in the second decade were quantitatively analyzed and visualized using visualization software such as VOSviewer (Leiden University, Leiden, Netherlands), CiteSpace (Drexel University, Philadelphia, Pa), and Scimago Graphica (SCImago Lab, Spain).

RESULTS

Institutions in the United States had the highest number of publications through the 2 decades, whereas Brazil, South Korea, and China achieved significant improvements in performance in the second decade compared with the first. Closer collaborative networks among scholars were revealed in the second decade. The cocitation analysis of the journals showed that highly cited journals included more professional orthodontic journals in the second decade than in the first decade.

CONCLUSIONS

Bibliometric analysis of publications in 3 major orthodontic journals over two 10-year periods revealed a trend of diversification in countries and institutions participating in publishing, international collaborations, and collaboration networks among authors in the field of orthodontics during the 2 decades.

Comparative assessment of two-phase class II treatment with Activator or Bionator followed by fixed appliances: A retrospective controlled before-and-after study

AIM

Two-phase treatment for children with Class II malocclusion with several functional appliances is still performed by many orthodontists, while the Activator and the Bionator appliances are two of the most popular ones. Aim of this study was to compare the skeletal and dentoalveolar effects of treatment with these two appliances.

METHODS

Class II children treated with Activator or Bionator in the first phase, followed by a phase of fixed appliances were included. Skeletal and dentoalveolar parameters were assessed from lateral cephalograms and analysed with linear regressions at 5%.

RESULTS

A total of 89 patients (mean age 10.0 years; 47% female) were included. During the first phase, Bionator increased less the SNB (difference in mean treatment-induced changes [MD] -0.7°; 95% confidence interval [CI] -1.3 to -0.2°; P=0.01) and decreased less the ANB angle (MD 0.6°; 95% CI 0 to 1.1°; P=0.03) compared to Activator. Activator slightly increased the facial axis and Bionator reduced it (MD -1.6°; 95% CI -2.3 to -0.8°; P<0.001). Compared to Activator, the Bionator retroclined more the upper incisors (MD -2.4°; 95% CI -4.6 to -0.2°; P=0.03) and increased more the interincisal angle (MD 2.9°; 95% CI 0.5 to 5.4°; P=0.02). After the second phase (6.2 years after baseline), the only differences were a reduced facial axis (MD -1.3°; 95% CI -2.2 to -0.3°; P=0.008) and an increased maxillary rotation (MD 0.9°; 95% CI 0 to 1.8°; P=0.04) with Bionator compared to Activator.

CONCLUSION

Similar dentoalveolar effects were seen overall with two-phase treatment with either appliance, with Bionator being associated with more vertical increase compared to Activator.

Impact of class II and class III skeletal malocclusion on pharyngeal airway dimensions: A systematic literature review and meta-analysis

Background

This study is a pioneer systematic review and meta-analysis aimed at comparing the influence of Class II and Class III skeletal malocclusions on pharyngeal airway dimensions. It stands as the inaugural comprehensive assessment to collate and analyze the disparate findings from previously published articles on this topic. The objective of this study was to identify published articles that compare the effects of class II and class III skeletal malocclusion on the pharyngeal airway dimensions.

Methods

An all-inclusive search for existing published studies was done to identify peer-reviewed scholarly articles that compared the influence of class II and class III skeletal malocclusion on pharyngeal airway dimensions. The search was done via five electronic databases: Cochrane Library, EMBASE, Scopus, Web of Science, and PubMed. Screening of the articles was done and the eligible studies were critically assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.

Results

The initial search yielded 476 potential articles of which, nine were finally included in this study for a total of 866 patients. Three studies were of cross-sectional design and six were of retrospective study design. Following a critical analysis and review of the studies, class III skeletal malocclusion had significantly larger volume and area measurements compared to class II skeletal malocclusion.

Conclusion

Research in the field of literature has established that variations in skeletal classifications have a discernible effect on the size of the pharyngeal airways. With the advancement of skeletal malocclusions to a class III, there is an observed increase in both the volume and cross-sectional area of the airways.

Evaluation of the skeletal and dental effects of a hybrid aesthetic functional appliance (HAF) in skeletal class II division 1 malocclusion: A prospective uncontrolled clinical trial

Background

The present study investigated the skeletal and dental effect in class II division I growing patients due to mandibular deficiency treated with the hybrid aesthetic functional (HAF) appliance.

Methods

A sample of 16 growing patients (5 boys and 11 girls; mean age: 9.50 years, standard deviation: 1.15) with class II division I malocclusion were treated using the HAF appliance for an average period of 10±3 months. For each patient, a cephalometric radiograph was taken before and after treatment, and digital analysis was applied using the WebCeph program. The statistical analysis was performed to evaluate dental and skeletal changes associated with the HAF appliance and determine if there were any statistically significant variations in anatomical measurements between the start and completion of the treatment.

Results

The data showed a significant increase in SNB angle (P=0.002), leading to a significant decrease in ANB angle (P=0.001). The mandibular length significantly increased (P=0.008), the lower incisors were flared significantly (P=0.028), and the lower molars were extruded significantly (P≤0.001). Also, this study revealed a significant decrease in Wits appraisal (P≤0.001), overjet (P≤0.001), and overbite (P=0.041). Additionally, a significant increase in lower anterior facial height (P≤0.001), total facial height (P=0.001), and posterior facial height (P=0.037) were observed.

Conclusion

The HAF appliance showed that it could be used to correct class II division 1 skeletal discrepancy by mandibular advancement. The HAF appliance increased all facial heights significantly.

The skeletal and dental effects of Hanks Herbst versus twin block appliances for class II correction in growing patients: a randomized clinical trial

BACKGROUND

Despite the popularity of the Twin Block (TB) and the Hanks Herbst (HH) functional appliances, there is limited prospective research comparing these removable and fixed designs, respectively.

OBJECTIVES

To evaluate and compare the skeletal and dental effects associated with TB and HH functional appliances as well as to detect factors that might influence the success or failure of treatment in adolescents with Class II malocclusion.

DESIGN AND SETTING

A parallel-group randomized controlled trial was undertaken in a single-centre hospital in the United Kingdom.

METHODS

A total of 80 participants (aged 10-14 years) with overjet of 7 mm or more were randomized to receive either the HH or TB appliance. Cephalometric radiographs were collected at the start of the study and immediately after the withdrawal of the functional appliances and measured using Pancherz analysis. Participants were allocated to the TB or HH group, based on an electronic randomization, stratified for gender and allocation concealed. Blinding to the allocated arm was not possible. However, all data were coded and anonymized to ensure that assessors were blinded to the group allocation. The main outcome was the anterior-posterior skeletal and dento-alveolar changes at the end of the functional phase.

RESULTS

Fifteen (37.5%) participants from the TB group and 7 (15.5%) from HH failed to achieve full overjet reduction (<4 mm) after 12 months of treatment. Overjet reduction was 2 mm greater with HH compared to TB (P = .05; 95% CI: 0.2, 3.2). No significant differences regarding skeletal and dental changes were reported, with the exception that participants in HH group experienced greater lower molar protraction (P = .002; 95% CI: -2.8, -0.8) and mandibular incisors advancement (P = .001; 95% CI: -2.9, -1), indicating greater dental than skeletal effects.

CONCLUSION

The TB appliance was associated with a higher rate of treatment discontinuation. No significant clinical differences were observed in the skeletal and dental effects, although the HH may be associated with more pronounced effects on the mandibular dentition.

CLINICAL TRIAL REGISTRATION

The protocol was registered online before the start of the trial (ISRCTN11717011).

Perceived Effects of Orthognathic Surgery versus Orthodontic Camouflage Treatment of Convex Facial Profile Patients

Increased facial profile convexity has a common occurrence in the population and is a primary reason for seeking orthodontic treatment. The present study aimed to compare the perceived changes in facial profile appearance between patients treated with combined orthognathic/orthodontic treatment versus only orthodontic camouflage treatment. For this reason, 18 pairs of before- and after-treatment facial profile photos per treatment group (n = 36 patients) were presented to four types of assessors (surgeons, orthodontists, patients, laypeople). Ratings were recorded on 100 mm visual analogue scales depicted in previously validated questionnaires. All rater groups identified minor positive changes in the facial profile appearance after exclusively orthodontic treatment, in contrast to substantial positive changes (14% to 18%) following combined orthodontic and orthognathic surgery. The differences between the two treatment approaches were slightly larger in the lower face and the chin than in the lips. The combined orthodontic and orthognathic surgery interventions were efficient in improving the facial appearance of patients with convex profile, whereas orthodontic treatment alone was not. Given the significant influence of facial aesthetics on various life aspects and its pivotal role in treatment demand and patient satisfaction, healthcare providers should take these findings into account when consulting adult patients with a convex facial profile.

Cephalometric changes in pharyngeal airway dimensions after functional treatment with twin block versus myobrace appliances in developing skeletal class II patients: a randomized clinical trial

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.

Comparison of masticatory myofunctional rehabilitation combined with conventional functional appliances for the treatment of class Ⅱ, division 1 malocclusion. A retrospective cohort study

OBJECTIVE

To estimate the clinical efficacy of early masticatory myofunction rehabilitation combined with conventional functional appliances for the treatment of class Ⅱ, division 1 malocclusion in orthodontic children during the growing phase.

MATERIALS AND METHOD

A comparative retrospective cohort study, enrolled patients diagnosed with class Ⅱ/1 in the stage of late mixed or early permanent dentition. Patients were divided into a TBA group (Cohort 1): receiving Twin-block appliance treatment; and a MMR group (Cohort 2): receiving either early masticatory myofunction rehabilitation as adjunctive therapy combined with the same conventional functional appliances. The study variables were active (Phase 1) treatment duration, oral esthetic subjective impact score (OASIS), several cephalometric indices calculated from X-ray photographs, the maximum voltage (mV) and asymmetry index (AsI) of anterior temporalis (TA) and masseter muscles (MM) before and after treatment. Complications were also recorded.

RESULTS

A total of 424 cases were enrolled. The mean treatment duration in the MMR group was 168.33 days (SD: 25.43) and 215.00 days (SD: 28.81) in the TBA group; mean difference: -46.67 days (95% CI: [-81.62, -11.71]), P<0.001. For the OASIS outcome measure, there was no statistically significant difference between the mean total scores for the MMR group (18.83±7.73) or TBA group (17.67±6.47) groups adjusted to include pre-treatment OASIS scores (P = 0.783). After treatment, sella-nasion-B point (SNB), mandibular incisor angle, maxillary base and mandibular base in both two groups were significantly increased, while AB plane angle (ANB), maxillary incisor angle, overjet and overbite were significantly decreased. The mV and AsI of TA and MM were also improved following treatment. However, no significant differences were observed between two groups.

CONCLUSION

Our results confirmed that early masticatory myofunction rehabilitation in combination with conventional TBA for patients in the growing phase was significantly effective in the management of class Ⅱ/1 in orthodontic treatment, which could significantly shorten the treatment duration and had the similar improvement in the cephalometry data, OASIS scores and masticatory muscles function when comparing to conventional TBA alone.

Skeletal Class II Malocclusion: From Clinical Treatment Strategies to the Roadmap in Identifying the Genetic Bases of Development in Humans with the Support of the Collaborative Cross Mouse Population

Depending on how severe it is, malocclusion, which may involve misaligned teeth, jaws, or a combination of the two, can hurt a person's overall facial aesthetics. The maxillary molar develops before the mandibular molar in class II malocclusion, which affects 15% of the population in the United States. With a retrusive mandible, patients typically have a convex profile. The goal of this study is to classify the skeletal and dental variability present in class II malocclusion, to reduce heterogeneity, present the current clinical treatment strategies, to summarize the previously published findings of genetic analysis, discuss these findings and their constraints, and finally, propose a comprehensive roadmap to facilitate investigations aimed at determining the genetic bases of malocclusion development using a variety of genomic approaches. To further comprehend the hereditary components involved in the onset and progression of class II malocclusion, a novel animal model for class II malocclusion should be developed while considering the variety of the human population. To overcome the constraints of the previous studies, here, we propose to conduct novel research on humans with the support of mouse models to produce contentious findings. We believe that carrying out a genome-wide association study (GWAS) on a large human cohort to search for significant genes and their modifiers; an epigenetics-wide association study (EWAS); RNA-seq analysis; integrating GWAS and the expression of quantitative trait loci (eQTL); and the testing of microRNAs, small RNAs, and long noncoding RNAs in tissues related to the skeletal class II malocclusion (SCIIMO) phenotype, such as mandibular bone, gum, and jaw in humans and the collaborative cross (CC) mouse model, will identify novel genes and genetic factors affecting this phenotype. We anticipate discovering novel genetic elements to advance our knowledge of how this malocclusion phenotype develops and open the venue for the early identification of patients carrying the susceptible genetic factors so that we can offer early prevention treatment strategies.

Retrospective investigation of the 3D effects of the Carriere Motion 3D appliance using model and cephalometric superimposition

OBJECTIVES

Carriere Motion 3D™ appliance (CMA) represents a method for molar distalization and correction of class II malocclusion. The aim was to investigate the 3D effects of the CMA by superimposing digital models and cephalometric X-rays.

MATERIALS AND METHODS

We retrospectively examined 16 patients treated with CMA in combination with class II elastics. We compared digitized models and cephalometric X-rays of records taken before therapy and after the removal of CMA. The records were superimposed to assess the skeletal and dentoalveolar changes. The results of the cephalometric X-ray analysis were compared to an untreated age- and gender-matched sample.

RESULTS

Class II occlusion was corrected after 11.85 ± 4.70 months by 3.45 ± 2.33 mm. The average distalization of the upper first molars was 0.96 ± 0.80 mm. The analysis of the cephalometric X-rays confirmed a distalization of the upper first molars with distal tipping and revealed a mesialization of the lower first molars of 1.91 ± 1.72 mm. Importantly, CMA resulted in a mild correction of the skeletal class II relationship (ANB: - 0.71 ± 0.77°; Wits: - 1.99 ± 1.74 mm) and a protrusion of the lower incisors (2.94 ± 2.52°). Compared to the untreated control group, there was significant distalization of the upper first molars and canines with mesialization and extrusion of the lower first molars.

CONCLUSION AND CLINICAL RELEVANCE

CMA is an efficient method for treating class II malocclusions. However, the class II correction is only partially caused by a distalization of the upper molars.

[The use of an individualized mini plate for the distalization of teeth]

The case of treatment of a 32-year-old patient with complaints about the aesthetics of a smile and the absence of teeth 17 and 46 is presented. During the examination, it was established: the retraction position of the teeth in the frontal part of the upper jaw, the closure of the molars according to the II class of the second subclass of Engl (distal bite), the vestibular position of the teeth 13, 23. To change the spatial position of the lower jaw, the fixation of the bracket system on the upper jaw was performed. and also an individualized mini-plate was installed in the area of the zygomatic alveolar ridge on the right and left, for distalization of the dentition of the upper jaw with the help of orthodontic traction applied from the teeth to the mini-plates. This clinical example demonstrates the possibility of using individualized mini-plates for distalization of the upper dentition, as an alternative and more stable method of treatment in such clinical cases.

Effects of Two-Phase Treatment with Functional Appliances Followed by Extraction versus One-Phase Treatment with Extraction in Class II Growing Patients: A Case-Control Study

Objectives: Fixed appliance treatment with premolar extraction is often required after functional appliance treatment to relieve crowding and improve facial aesthetics in the Asian population. This study compared the treatment efficacy of two approaches for treating Class II division 1 malocclusion: functional appliance followed by fixed appliance treatment with extraction (two-phase) and fixed appliance treatment with extraction (one-phase). Methods: Growing skeletal Class II patients with an overjet of ≥6 mm treated with two- or one-phase orthodontics were included. The two groups consisted of 29 patients (mean age = 12.55) and 30 patients (mean age = 12.72), respectively. Pre- and post-treatment cephalograms were analysed and skeletal, dental, and soft tissue characteristics were compared using independent t-tests. Treatment changes were compared within and between groups using paired and independent t-tests, respectively. Stepwise discriminant analysis was performed to identify the variables that best predicted pre-treatment group allocations. Results: At baseline, there were no significant between-group differences in age, gender, cervical vertebral maturation, or overjet. The two-phase group had greater Class II skeletal discrepancies (ANB angle and Wits appraisal). During treatment, the two-phase group showed greater improvements in intermaxillary relationship and facial convexity compared with the one-phase group (p < 0.01). Following treatment, the two-phase group had a greater L1/APog distance (p < 0.05). Facial convexity and Wits appraisal were identified as parameters significantly influencing the clinicians’ decision to use a one- or two-phase approach. Conclusions: In patients requiring premolar extraction, two-phase (vs. one-phase) treatment produced greater improvements in the intermaxillary relationship and facial convexity.

Orthodontic Compliance Assessment: A Systematic Review

OBJECTIVES

The aim of this review was to determine whether the type of removable appliance, as well as the age and sex of the patient, may affect the extension or reduction of wear time by assessing the correlation between the mean actual and orthodontist-recommended wear times.

METHODS

Randomised case control trials, cohort studies, case series, observational studies, reviews, and retrospective analyses were identified. The quality of the studies was assessed using the Cochrane Collaboration Tool and modified Newcastle-Ottawa Scale. The electronic databases Embase, PubMed, Scopus, and Web of Science were reviewed, and 542 articles were obtained, of which 31 were qualified for qualitative synthesis. The data from 1674 participants were collected and a weighted average was determined for the mean wear time of each appliance.

RESULTS

Regardless of the type of extra- or intraoral appliances, mean wear time was shorter than recommended, although patients using intraoral appliances cooperated more. The best compliance was noted for Schwarz appliances (73.70%) and plate retainers (85%). There was no evidence of an influence of patients' age and sex on compliance during treatment.

CONCLUSIONS

The considerable inconsistency and imprecision of articles could affect the reliability of the results. Previous studies analysing the effectiveness of treatment with removable appliances based on an arbitrarily assumed average wear time need to be revised in order to verify the actual wear time with the use of microsensors.

Bibliometric analysis of research publications in three major orthodontic journals during 2012–2021

Objectives:

This study conducted a comprehensive bibliometric analysis of articles published from 2012 to 2021 in three orthodontic journals: The American Journal of Orthodontics and Dentofacial Orthopedics (AJODO), The Angle Orthodontist (AO), and European Journal of Orthodontics (EJO).

Material and Methods:

Eligible articles published from 2012 to 2021 in AJODO, AO, and EJO were retrieved from the Web of Science Core Collection database and subsequently processed using CiteSpace software to generate their characteristics, including authorship, institution, geographic origin, keywords, and citation profiles.

Results:

The three orthodontic journals published 4001 articles from 370 institutions in 95 countries from 2012 to 2021. The AJODO published the most articles (45.5%) followed by AO (31.3%) and EJO (23.2%). The most prolific country was the United States (US), followed by Brazil, South Korea, China, and Turkey. The authors from the US were heavily engaged in international collaborations, especially with South Korea and Brazil. The country and institutions with the highest citation counts per publication were Italy and the University of Bern (Switzerland), respectively. Pandis N was the most prolific author, and Proffit W was the most-cited author in the 4001 publications. The keywords that emerged most frequently were “children” followed by “orthodontic treatment” and “malocclusion.” Four of the 10 most-cited articles were related to digital dental technology.

Conclusion:

This bibliometric analysis provides a complete picture of the research published in three major orthodontic journals over the past decade. It comprehensively analyzes the authorship, country of origin, institutions, keywords, and citation profiles of the articles.

Effect of Point-of-Care Ultrasound on Clinical Outcomes in Low-Resource Settings: A Systematic Review

Despite the potential for improved patient care, little is known of the true effect of point-of-care ultrasound (POCUS) on patient outcomes in resource-limited settings. Electronic databases were searched using medical subject heading and free text terms related to POCUS and resource-limited settings through August 2020. Two authors independently selected studies, assessed methodological quality using the Downs and Black scale and extracted data. Twenty observational studies were included in the final review. All studies had moderate to high risk of bias. No studies exhibited an effect on the pre-specified primary outcome of mortality. Varying degrees of change in differential diagnosis and management were reported, but definitions varied widely among studies. Estimates for change in diagnosis as a result of POCUS ranged from 15% to 52%, and those for change in management, from 17% to 87%. Articles on POCUS clinical utility represent a small part (4.6%) of the scholastic literature dedicated to POCUS in low-resource settings. POCUS is a valuable intervention to consider in resource-limited settings, with the potential to change diagnosis and patient management. The exact magnitude of effect remains unknown. There is a continued need for large-scale experimental studies to investigate the effect of POCUS on patient diagnosis, management and mortality.

Skeletal and dentoalveolar effects of class II malocclusion treatment using bi-maxillary skeletal anchorage: a systematic review

BACKGROUND

The goal of this systematic review was to assess the available evidence regarding the skeletal and dentoalveolar effects of bi-maxillary skeletal anchorage devices (BMSADs) used in treating growing class II malocclusion patients.

METHODS

A comprehensive search was conducted on PubMed, Scopus, Science Direct, Web of Science, Cochrane, and LILACS up to November 2021, which was augmented by a manual search. The studies included were clinical trials (RCTs) and/or follow-up observational studies (retrospective and prospective). The outcomes of interest were the skeletal, dentoalveolar, and occlusal treatment-induced changes obtained from pre- and post-cephalometric measurements. The risks of bias of the included studies were assessed using an assessment tool from previous publications.

RESULTS

Out of 742 screened articles, only 4 were eligible and thus included in the qualitative synthesis. They showed a moderate overall risk of bias. The results are presented as mean changes in both the study and control groups. All studies reported retrusion of the maxillary base and advancement of the mandible (meaning reduced ANB angle). Three of the included studies reported an increase in the vertical jaw relation, which was contrary to what the fourth study reported. Three studies reported an increase in the maxillary incisors' inclination or position, while one study reported their retroclination. Proclination of the mandibular incisors happened in two studies, whereas the other two studies reported retroclination. The overjet was reduced in all included studies.

CONCLUSION

Apart from the protrusive effects on the mandible, retrusive effects on the maxilla, and the consequent reduction of the overjet, BMSADs results in inconsistent skeletal and dentoalveolar effects. However, the current evidence is limited due to the variability in the biomechanics of the intermaxillary components, type of anchorage, and comparable groups in the included studies. Further RCTs with more standardized methodologies are highly encouraged.

CLINICAL RELEVANCE

BMSADs (using miniscrews or miniplates on both jaws) induces more skeletal than dentoalveolar effects. However, this must be practiced with caution, based on the benefit to risk (surgical insertion) ratio, and the limited evidence available in hand so far. Registration The protocol for this systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO, No.: CRD42020199601).

Effect of low-level laser therapy on condylar growth in children treated with functional appliance: a preliminary study

Purpose

This study aimed to evaluate the skeletal and dentoalveolar changes achieved by combining low-level laser irradiation applied on the condyle area with twin-block therapy in growing class II malocclusion patients.

Methods

Fourteen patients (9 males, 5 females; mean age, 11.4 ± 2 years) with skeletal class II mandibular deficiency were recruited. They were divided into two groups (G 1: twin-block + low-level laser therapy, G 2: twin-block only). A semiconductor diode laser with a wavelength of 940 nm was applied on the condyle area (100 mW, 2.5 J, 3.9 J/cm²). The laser was applied twice a week in the first month and once a week in the second and third months, totalizing 16 sessions. Skeletal, dental, and soft-tissue cephalometric parameters were measured and compared at different treatment points.

Results

Mandibular length (Co-Gn) was significantly increased by 3.6 mm in the experiment group (3.16 SD) and 4.3 mm (4.4 SD) in the control group, with no significant difference between groups at every time point (P-value 0.949 at T2). Similarly, a statistically significant positive effect of treatment was found in both groups on ramus height (Co-Go), upper lip to E-Line, SNA angle, ANB angle, and U1/SN angle with no significant difference between groups.

Conclusion

Based on the results of this preliminary study, low-level laser irradiation with the used parameters seems to have no synergetic impact on the skeletal and dental outcomes of twin-block therapy over 9 months. However, more studies are needed to investigate the effect of low-level laser therapy on condylar growth during functional orthodontic treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41547-022-00158-x.

The Use of Microsensors to Assess the Daily Wear Time of Removable Orthodontic Appliances: A Prospective Cohort Study

Orthodontic treatment with removable appliances is still common in children and adolescents. However, their effectiveness depends primarily on the patients’ compliance. Currently, it is possible to check the daily wear time (DWT) of the removable appliances using special microsensors. The aim of this prospective cohort study was to assess the degree of patients’ compliance depending on the type of removable appliance used. In total, 167 patients (87 F, 80 M) were enrolled in the study and were treated with block appliances (Klammt, Twin-Block), Schwarz plates, and block appliances in combination with headgear. All patients were followed up for 6 months with the mean daily wear time checked at followup visits using TheraMon^® microsensors fitted in the appliances. It has been shown that the type of appliance influences the patients’ compliance. The DWT for the Twin Block was significantly longer compared to the DWT for the other appliances. Girls have been shown to wear removable appliances better than boys. It has been proven that the majority of patients do not follow the orthodontist’s recommendations, wearing removable appliances for just over half of the recommended time. Microsensors can be used for objective verification of patients’ compliance, which allows for a reliable assessment of the effectiveness of treatment with removable appliances.

Effectiveness of functional orthodontic appliances in obstructive sleep apnea treatment in children: literature review

INTRODUCTION

Obstructive sleep apnea syndrome is a common condition in childhood and if left untreated can result in many health problems. An accurate diagnosis of the etiology is crucial for obstructive sleep apnea treatment success. Functional orthodontic appliances that stimulate mandibular growth by forward mandibular positioning are an alternative therapeutic option in growing patients.

OBJECTIVE

To perform a literature review about the effects of functional orthodontic appliances used to correct the mandibular deficiency in obstructive sleep apnea treatment.

METHODS

The literature search was conducted in June 2020 using Cochrane Library; PubMed, EBSCO (Dentistry & Oral Sciences Source), LILACS Ovid; SciELO Web of Science; EMBASE Bireme and BBO Bireme electronic databases. The search included papers published in English, until June 2020, whose methodology referred to the types and effects of functional orthopedic appliances on obstructive sleep apnea treatment in children.

RESULTS

The search strategy identified thirteen articles; only four articles were randomized clinical studies. All studies using the oral appliances or functional orthopedic appliances for obstructive sleep apnea in children resulted in improvements in the apnea-hypopnea index score. The cephalometric (2D) and tomographic (3D) evaluations revealed enlargement of the upper airway and increase in the upper airspace, improving the respiratory function in the short term.

CONCLUSION

Functional appliances may be an alternative treatment for obstructive sleep apnea, but it cannot be concluded that they are effective in treating pediatric obstructive sleep apnea. There are significant deficiencies in the existing evidence, mainly due to absence of control groups, small sample sizes, lack of randomization and no long-term results.

Upper Airway Changes in Diverse Orthodontic Looms: A Systematic Review and Meta-Analysis

Upper airway assessment is particularly important in the daily work of orthodontists, because of its close connection with the development of craniofacial structures and with other pathologies such as Obstructive Sleep Apnea Syndrome (OSAS). Three-dimensional cone-beam computed tomography images provide a more reliable and comprehensive tool for airway assessment and volumetric measurements. However, the association between upper airway dimensions and skeletal malocclusion is unclear. Therefore, the current systematic review evaluates the effects of different surgical movements on the upper airway. Materials and Methods: Medline (PubMed, OVID Medline, and EBSCO), Cochrane Library (Cochrane Review and Trails), Web of Knowledge (social science, and conference abstracts), Embase (European studies, pharmacological literature, and conference abstracts), CINAHL (nursing and allied health), PsycInfo (psychology and psychiatry), SCOPUS (conference abstracts, and scientific web pages), and ERIC (education) databases were searched. Two authors independently performed the literature search, selection, quality assessment, and data extraction. Inclusion criteria encompassed computed tomography evaluations of the upper airway spaces with retrospective, prospective, and randomised clinical trial study designs. To grade the methodological quality of the included studies a GRADE risk of bias tool was used. Results and conclusion: In total, 29 studies were included. Among these, 17 studies had a low risk of bias, whereas 10 studies had a moderate risk of bias. A meta-analysis was performed with the mean differences using a fixed-effects model. Heterogeneity was assessed with the Q-test and the I2 index. The meta-analysis revealed significant (p ≤ 0.001, 95% confidence interval) increases in upper airway volume after rapid maxillary expansion and surgical advancement for the correction of Class II.

Cephalometric analysis of dental and skeletal effects of Carriere Motion 3D appliance for Class II malocclusion

INTRODUCTION

The objective was to describe the dental and skeletal changes obtained using the Carriere Motion Appliance (CMA), lateral cephalogram, and the corresponding cephalometric tracings.

METHODS

A sample of 29 patients with Class II malocclusion (mean age, 12.6 ± 1.7 years) was retrospectively selected. All patients were treated at a single center using a CMA as the primary sagittal correction device. Cephalometric tracings at the beginning and end of treatment were compared. Each cephalometric tracing was performed 3 times by the same operator.

RESULTS

Using the CMA, the 29 patients studied reached dental Class I in 4.4 ± 0.98 months. All measurements were subjected to statistical analysis, paired t test, and all displayed differences between T0 and T1 (P <0.05) except for the SNA. At the end of treatment, the Wits and ANB values were reduced by 1.38 mm and 0.8°, respectively. Overbite and overjet were also reduced by 1.4 mm and 2 mm, respectively. The SNB, FMA, LAFH, and IMPA increased to a lesser extent (ie, 0.7°, 0.4°, 1.5 mm, and 1.5°, respectively).

CONCLUSIONS

The CMA is a rapid and efficient means of correcting Class II malocclusion. Its effects are predominantly dentoalveolar, with minimal skeletal alteration of little clinical significance.

Treatment effects of the MARA appliance and Activator-Headgear combined with fixed appliances in Class II division 1 malocclusion patients: A retrospective longitudinal study

Introduction:

Class II division 1 malocclusion treatment with functional devices offers acceptable results. These devices can be removable or fixed, and the essential difference between them is the need for compliance. It is clinically important to investigate if there are differences in the treatment effects of these devices that present different characteristics.

Objective:

This retrospective longitudinal study compared the treatment effects of Class II correction with the MARA appliance, Activator-Headgear (AcHg) combination, both followed by multibracket fixed appliances, and an untreated control group.

Material and Methods:

Each experimental group was composed of 18 patients, with a baseline mean age of 11.70 and 10.88 years, treated for 3.60 and 3.17 years. The control group consisted of 20 subjects with baseline mean age of 11.07 years. The groups were evaluated before (T1) and after (T2) treatment. Lateral radiographs were used to evaluate the treatment changes with treatment (T2-T1), compared to the control group. Intergroup comparisons were performed using repeated-measures analysis of variance (ANOVA), followed by Tukey’s test.

Results:

The AcHg group showed significantly greater maxillary growth restriction than the MARA, while the mandibular changes were due to natural growth. Both devices promoted significantly greater maxillary incisors retrusion, mandibular incisors labial inclination, and improvement of overjet and molar relationships, compared to the control.

Conclusions:

Both functional devices followed by multibracket appliances were effective to correct Class II malocclusion. Nonetheless, the AcHg combination presents superior skeletal effects, due to significantly greater maxillary growth restriction compared to the MARA appliance. Moreover, the appliances presented similar dentoalveolar effects.

Mandibular incisor inclination and gingival recession after treatment with the Jasper Jumper: a 10-year follow-up

OBJECTIVE

To evaluate the long-term outcomes of Class II treatment with the Jasper Jumper appliance and comprehensive orthodontic treatment concerning inclination of the mandibular incisors and gingival recession.

METHODS

Sixteen patients with Class II malocclusion at a mean age of 12.54y (SD = 1.17) were treated with the Jasper Jumper appliance and comprehensive orthodontic treatment. The mean treatment time was 2.05y (SD = 0.21). Dental records were taken before (T1), after treatment (T2) and 11.90y (SD = 0.48) after debonding (T3). The frequency of gingival recession, clinical crown height and mandibular incisor position were evaluated using intraoral photographs, digital models and lateral cephalograms. Interphase changes were evaluated using dependent t and McNemar's tests. Correlation between clinical crown height and final position of the mandibular incisors was evaluated using Pearson correlation test (P < 0.05).

RESULTS

The frequency of gingival recessions increased over time and was observed in 6 (9.4%), 12 (18.8%) and 24 (37.5%) of the mandibular incisors at T1, T2 and T3, respectively. A significant increase in labial inclination and protrusion of the mandibular incisors was observed between T1 and T2 interval. The clinical crown height significantly increased in the follow-up period (T3-T2) and in the complete observation time (T3-T1). There was no correlation between the amount of labial inclination and protrusion of the mandibular incisors and clinical crown height for all time intervals.

CONCLUSION

No significant correlation between the amount of labial movement of the mandibular incisor and clinical crown height increase was found.

Comparison of AdvanSync2® and Twin Block Appliances in Treatment of Class II Malocclusion With Retrognathic Mandible—An Observational Retrospective Study

Objectives:

To evaluate the treatment outcomes between Twin Block and AdvanSync2® appliances by comparing the skeletal, dentoalveolar, and soft tissue changes.

Materials and Methods:

Radiographic data of 20 patients were retrospectively analyzed. Data were selected from patients in their skeletal growth spurt as evaluated by the cervical vertebral maturation method (CVMI 2, 3, and 4), with class II malocclusion characterized with retrognathic mandible (ANB > 4°, SNB < 77°, FMA = 25 ± 5°, overjet > 5 mm). There were 10 patients in each group that underwent orthodontic correction for class II malocclusion: either using Twin Block or AdvanSync2®. Independent t test and Paired t test and chi-square tests were used for the data analysis. The level of statistical significance was set at P value ≤.05.

Results:

The chronological and skeletal age were similar in both the groups. Records were taken for the functional treatment with mean treatment span of 8 ± 1 month. Changes in SNB (group I = 1.59°, group II = 3.11°) ( P < .01), Co-Gn (group I = 2.89 mm, group II = 5.34 mm), and U1-L1° (group I = −1.51°, group II = 2.97°) showed statistically different outcome between the groups, when the pre-post data were studied. Rest of the variables—cranial base, maxillary skeletal, mandibular skeletal, intermaxillary, vertical skeletal, maxillary dentoalveolar, mandibular dentoalveolar, and soft tissue—showed similar outcome ( P > .05).

Conclusion:

Both appliances lead to desirable outcomes in the correction of class II malocclusion. AdvanSync2® resulted in inducing more of changes in SNB and effective mandibular length as compared to Twin Block. Overjet and molar relation improved significantly with both the appliances. Both the appliances resulted in similar skeletal, dentoalveolar, and soft tissue changes.

ADDING TEMPORARY ANCHORAGE DEVICES (TADs) TO THE FORSUS™ CLASS II CORRECTION SYSTEM MAY NOT ENHANCE THE SAGITTAL SKELETAL EFFECTS BUT MAY CONTROL THE INCLINATION OF THE MANDIBULAR INCISORS

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

A comparison of the effects of Forsus appliances with and without temporary anchorage devices for skeletal Class II malocclusion. Liu L, Zhan Q, Zhou J, Kuang Q, Yan X, Zhang X, Shan Y, Lai W, Long H. Angle Orthod. 2020 Dec 30. doi:10.2319/051120-421.1. Epub ahead of print. PMID: 33378419.

SOURCE OF FUNDING

National Natural Science Foundation of China (No. 82,071,147, 81,571,004, and 81,500,884).

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis.

Functional appliance treatment for mandibular fractures: A systematic review with meta-analyses

OBJECTIVES

Mandibular collum fractures among growing patients can lead to abnormal growth, function, esthetics and ultimately quality of life. Among the proposed treatment alternatives, orthopaedic treatment with functional appliances has been suggested, with encouraging results. Aim of the present systematic review was to critically appraise existing evidence on the outcome of functional appliance treatment among growing patients with mandibular collum fractures.

MATERIALS AND METHODS

Eight databases were searched up to October 2020 for randomised and non-randomised clinical studies assessing functional appliance treatment outcome for children with mandibular fractures. After duplicate study selection, data extraction and risk of bias assessment, random effects meta-analyses of mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by assessment of the quality of evidence with GRADE.

RESULTS

A total of 8 unique studies (one prospective and nine retrospective non-randomised) with 223 children could be identified. Functional appliance treatment was associated with greater anteroposterior condyle dimensions of the injured condyle compared with the contralateral healthy condyle (3 studies; MD = 0.87 mm; 95% CI = 0.30 to 1.45 mm; p = .003). No difference was found in the mesiodistal condyle size between the injured and the contralateral healthy joint (3 studies; MD = -0.05 mm; 95% CI = -1.05 to 0.95 mm; p = .92), but collum length was smaller at the injured side compared with the contralateral one (1 study; MD = -2.89 mm; 95% CI = -5.29 to -0.49 mm; p = .02). Treatment outcome might be influenced by patient age, patient sex and severity/localisation of the fracture, but the quality of evidence for all analyses was very low due to methodological limitations leading to bias.

CONCLUSIONS

While some evidence exists that functional appliances might lead to good clinical rehabilitation of fractured mandibular condyles, including considerable bone remodelling, available studies are small and have methodological weaknesses.

Effect of Class II functional treatment on facial attractiveness, as perceived by professionals and laypeople

The literature offers different perspectives for and against two-phase treatment of skeletal Class II malocclusion. Facial attractiveness is an important aspect to take into account, given that children with skeletal Class II are often bullied by their peers and have low self-esteem and a lower social perception. The aim of the present study was to evaluate the aesthetic perception of facial profiles by a large number of observers, before and after treatment with a functional appliance, compared to untreated controls. The pre- and post-treatment cephalograms of 20 Class II subjects treated with Sander’s bite-jumping appliance and 20 untreated historical controls were collected and transformed into black and white silhouettes depicting only the lower third of the face. An online questionnaire comprising the silhouettes of the two groups, three “calibration” profiles and an “ideal” profile was submitted to dentists, orthodontists, undergraduates and laypeople, asking them to rate the profile’s attractiveness using a Visual Analogue Scale (VAS). The effect of treatment, and observers’ age, expertise and gender were analysed. The calibration images and the ideal profiles were used to evaluate the coherence of each observer’s judgement. The protocol was approved by the local Ethics Committee. Nine-hundred and ten questionnaires were collected. Treated subjects showed a larger improvement of facial attractiveness compared to controls. A significant effect of gender on the observer’s ratings was observed. Some observers showed incoherent judgement, which had a significant effect on the regression model. In conclusion, early treatment with functional appliances seems to improve patients’ facial aesthetics. This improvement is perceived equally by dental professionals and laypeople.

Comparative Evaluation of Esthetic and Structural Aspects in Class II Functional Therapy. A Case-Control Retrospective Study

Background: To compare the skeletal, dental, and esthetic changes produced by three functional devices, Fränkel-2 appliance (FR-2), Twin Block (TB), and Occlus-o-Guide® (O-o-G®), for the treatment of Class II malocclusion. Methods: Sixty-five patients with Class II Division 1 malocclusion were divided into three groups and were analyzed through cephalometric analysis of skeletal, dental, and esthetic variables before and after treatment. The first group of 23 patients (F: 9; M: 14; mean age: 10.3 ± 1.08 years) was treated with FR-2, the second group of 18 patients (F: 8; M: 10; mean age 10.7 ± 1.05 years) was treated with TB, the third group (F: 11; M: 13; mean age: 9.05 ± 0.39 years) of 24 patients was treated with O-o-G®. The structural effects of the three devices were compared with a control group generated by the growth variations reported in the cephalometric atlas of Bhatia and Leighton. Esthetic analysis was performed comparing the results of the patients treated with a control group of 20 subjects with mandibular retrognathia and Class II Division 1 malocclusion, not subjected to therapy. Results: The three devices resulted in a significant increase in mandibular length, with higher results obtained for FR-2 and TB. A statistically significant increase in the IMPA angle was found for the O-o-G® group, and a notable reduction of both overjet and overbite was detected in all three groups of treated patients. The esthetic evaluation showed overall more significant results in the TB group, especially with regard to the reduction of facial convexity. The retrusion of the upper lip was on average more significant in the O-o-G® group, followed by that in the TB. Conclusions: All three devices have proven to be effective overall in resolving skeletal changes and improving facial esthetics.

Skeletal and dental effects of Herbst appliance anchored with temporary anchorage devices: A systematic review with meta-analysis

BACKGROUND

The aim was to evaluate the efficiency of using temporary anchorage devices (TADs) in minimizing the anchorage loss and increasing the skeletal effects during correction of Class II malocclusion with Herbst appliance.

MATERIALS AND METHODS

Search without restrictions was performed up to January 2021 in three electronic databases (CENTRAL, MEDLINE and EMBASE) for randomized controlled trials (RCTs), prospective and retrospective cohort studies. The included studies assessed the dental and skeletal changes in Class II malocclusion patients who were treated using Herbst appliance with or without TADs. The strength of evidence was ranked using GRADE.

RESULTS

Fifty-five records were initially retrieved. A total of 6 studies with 198 patients were finally considered. 4 studies were included in the meta-analysis. The meta-analysis showed that using TADs with acrylic splint Herbst appliance was effective in controlling the inclination of mandibular incisors by a mean difference of -5.49 degrees (95% C.I [-7.36, -3.63], P < .001) when compared to Herbst appliance alone. The results showed also that incorporating TADs with Herbst treatment resulted in greater mandibular skeletal effects including increasing mandibular bone base length by mean difference of 2.22 mm (95% C.I [0.82. 3.61], P = .002) and mandibular length by mean difference of 3.7 mm (95% C.I [1.55, 5.85], P < .001) when compared to Herbst appliance alone.

CONCLUSIONS

Based on a very low level of confidence, it seems that incorporating TADs during orthodontic treatment with Herbst appliance results in minimizing the anchorage loss and increasing the skeletal effects of Herbst appliance during correction of Class II malocclusion.

Motor learning might contribute to a therapeutic anterior shift of the habitual mandibular position-An exploratory study

BACKGROUND

Passive mandibular advancement with functional appliances is commonly used to treat juvenile patients with mandibular retrognathism.

OBJECTIVE

The aim of this study was to investigate whether active repetitive training of the mandible into an anterior position would result in a shift of the habitual mandibular position (HMP).

METHODS

Twenty adult healthy subjects were randomly assigned to one of two groups: a training group receiving six supervised functional training sessions of 10 min each and a control group without training. Bonded lateral biteplates disengaged occlusion among both groups throughout the 15-day experiment. Customised registration-training appliances consisted of a maxillary component with an anterior plane and a mandibular component with an attached metal sphere. Training sessions consisted of repeated mouth-opening/closing cycles (frequency: 30/min) to hit an anteriorly positioned hemispherical target notch with this metal sphere. The HMP was registered at defined times during the experiment.

RESULTS

The HMP in the training group showed a statistically significant anterior shift of 1.6 mm (interquartile range [IQR]: 1.2 mm), compared with a significant posterior shift of -0.8 mm (IQR: 2.8 mm) in the control group (p < .05). Although the anterior shift among the training group showed a partial relapse 4 days after the first training block, it then advanced slightly in the 4-day interval after the second training block, which might indicate neuroplasticity of the masticatory motor system.

CONCLUSIONS

Motor learning by repetitive training of the mandible into an anterior position might help to improve the results of functional appliance therapy among patients with mandibular retrognathism.

Does daily wear time of Twin Block reliably predict its efficiency of class II treatment?

PURPOSE

The objective of this study was to investigate how daily wear time (DWT) influences class II malocclusion treatment efficiency.

MATERIALS AND METHODS

The study group consisted of 55 patients (mean age 10.4 years) diagnosed with a class II/1 malocclusion. Twin block appliances, with built-in Theramon® microsensors (MC Technology, Hargelsberg, Austria) to monitor patients' cooperation (daily wear time assessment), were used for treatment. Cephalograms were taken and the following initial and final measurements were compared: Co-Gn, Co-Go, Co-Olp, Pg-Olp, WITS, SNA, SNB, ANB, Co-Go-Me, overjet, molar and canine relationships. The Shapiro-Wilk test, Wilcoxon signed-rank test, Student's t-test, Levene's test, Mann-Whitney U test, Kruskal-Wallis test, χ² test, and Spearman's rank correlation coefficient with p < 0.05 set as the statistical significance level were used to determine the correlation of the outcomes with DWT; a ROC (receiver operating characteristic) curve was calculated to illustrate diagnostic ability of the binary classifier system.

RESULTS

DWT was very highly positively correlated with change of the Pg-Olp parameter and highly with an improvement in the ANB, SNA, and SNB angles, an increase in the WITS parameter and an increase in Co-Gn distance. DWTs < 7.5 h correlated with significantly less improvement of the investigated variables. However, DWT > 7.5 h did not significantly correlate with the improvement of the overjet and most of the linear parameters in the mandible. The ROC curve and its AUC (area under curve) allowed the determination of a DWT of 7 h and 48 min to be capable of establishing a class I relationship with 83% probability.

CONCLUSIONS

Class II treatment efficiency was influenced by DWT; an 8 h threshold value had an 83% probability of establishing a class I relationship.

Three-Dimensional Evaluation of Soft Tissue Changes after Functional Therapy

This study was aimed at proposing a three-dimensional (3D) evaluation method for the soft tissue effects of Twin Block (TB) functional appliance therapy by using cone beam computed tomography (CBCT) images. In this retrospective study, a total of 60 pre- and posttreatment (T0 and T1) CBCT images of Class II patients with mandibular retrognathia treated with a TB appliance were used. Volumetric and linear soft tissue changes were evaluated quantitatively with 3D measurements and qualitatively with color mapping visual. Linear (NV-A and NV-Pog) and angular (SNA, SNB, and ANB) skeletal changes were also measured on 3D images. The Wilcoxon signed-rank test was used to compare statistical differences, and the scores of male and female participant differences were observed with the Mann-Whitney U test. In this study, a decrease was observed in SNA (p < 0.05), ANB (p < 0.01), and NV-Pog (p < 0.05) while an increase in SNB (p < 0.01) was found. However, decrease in NV-A distance was not statistically significant (p > 0.05). As a result of the evaluation of soft tissue changes, while the anterior reposition of the lower lip, soft tissue pogonion, and soft tissue gnathion was found to be significant (p < 0.01, p < 0.01, and p < 0.05, respectively), the upper lip and subnasale repositions were not statistically significant (p > 0.05). 3D soft tissue changes after TB therapy can be evaluated quantitatively and qualitatively by using CBCT images. Anterior repositioning of the mandible with functional therapy also provides improvement in soft tissue profile, especially in the lower facial region.

Soft tissue evaluation of functional therapy in growing patients with Class II malocclusion: a long-term study

OBJECTIVE

The objective of this study was to analyse the soft tissue changes produced by the functional treatment of mandibular advancement in growing Class II patients.

MATERIALS

The treated group consisted of 25 Caucasian patients (12 females and 13 males) with dento-skeletal Class II malocclusion treated with functional therapy (Activator). All patients were evaluated before treatment (T1; mean age, 9.9 years), at the end of functional treatment phase (T2; mean age, 11.9 years), and at a post-pubertal follow-up observation (T3; mean age, 18.5 years). The treated group was compared with a matched control group of 25 untreated subjects (13 females, 12 males) with untreated Class II division 1 malocclusion. Statistical comparisons between the two groups were performed with independent samples t-tests (P < 0.05).

RESULTS

Significant improvements were found during the long-term interval for mandibular sulcus (9.9°) and the profile facial angle (9.8°) in the treated group. No significant effects were found in terms of lower face percentage between the two groups.

CONCLUSION

Removable functional appliances induced positive effects on the soft tissue profile in Class II growing subjects with good stability in the long-term.

Skeletal and dental changes induced by the Flip-Lock Herbst appliance in the treatment of Angle's class II division 1 malocclusion during active growth period: A preliminary study

Background. The Flip-Lock Herbst (TP Orthodontics Inc.) is a fixed functional appliance, a variant of the Herbst appliance, introduced by Miller. It is claimed to have better patient tolerance due to its increased freedom for the mandible's lateral movements. There have been no studies on the flip lock Herbst till date. This study was undertaken to assess the efficiency of the Flip-Lock Herbst appliance in correcting Angle's class II division 1 malocclusion. Methods. Eight subjects in their active growth period with class II division 1 malocclusion due to a retrognathic mandible were included in the study. Standardized lateral cephalometric radiographs were used to evaluate skeletal and dental changes with the SO analysis. Paired samples t-test was used to assess statistical significance. Results. Statistically significant increases in mandibular length (pg/OLp) and effective mandibular length (ar/OLp + pg/OLp) were observed. There was a significant maxillary restraining effect. Dental effects were significant and exhibited class II correction features except for the position of lower incisors within the mandible (ii/OLp - pg/OLp). Skeletal changes accounted for 61% and dental changes for 39% of the total treatment for molar correction. For overjet correction, skeletal changes contributed to 63% and dental changes to 37% of the total treatment. Conclusion. The Flip-Lock Herbst appliance was efficient in correcting Angle's class II division 1 malocclusion due to a retrognathic mandible. Both skeletal and dental changes were evident, with the former predominating (60:40).

Changes of epiglottis and hyoid bone position after orthodontic treatment with cast splint fixed functional appliances

OBJECTIVES

Angle Class II malocclusions including a retrognathic mandible are the most frequent orthodontic problems. Both removable and fixed functional appliances can be used for mandibular advancement. Mandibular advancement after treatment with any fixed functional appliance has numerous therapeutic effects, such as stretching of masticatory muscles, ligaments, membranes and surrounding soft tissues, thus causing positional changes of the hyoid bone and epiglottis. This retrospective study investigates and compares treatment effects upon epiglottis- and hyoid bone position and posterior airway space in class II patients who received mandibular advancement through two different cast splint fixed functional appliances.

MATERIAL AND METHODS

Two groups of 21 patients each ('Functional Mandibular Advancer' (FMA) and Herbst appliance) were investigated. The same experienced orthodontist performed the treatment in all patients, employing a single-step advancement protocol. The mandible always received initial protrusion into an edge-to-edge position. Conventional lateral cephalograms were available pre-treatment (T1) and immediately after appliance removal (T2) for all patients. The measurements comprised (I) hyoid bone, (II) epiglottis or (III) posterior airway space. Treatment-related changes were analysed with one-sample Student's t tests for intragroup comparisons and independent Student's t tests for intergroup comparisons. Statistical significance was set at p < 0.05.

RESULTS

Measurements of the hyoid bone showed mostly increases for both appliances after treatment. Intergroup comparisons were not significant for FMA patients but significant for selected measurements in Herbst appliance patients. Intergroup comparisons showed insignificant changes. The posterior airway space was always insignificantly increased after treatment. The greatest increase was found caudally. Intergroup comparisons showed insignificant changes.

CONCLUSIONS

Both fixed functional appliances cause an anterior and caudal displacement of epiglottis and hyoid bone and enlarge the posterior airway space. The therapeutic effects of the Herbst appliance are slightly larger, although not significantly.

CLINICAL RELEVANCE

Treatment with either Herbst appliance of FMA alters the hyoid bone position and enlarges the posterior airway space. Still, long-term data are as yet unavailable; it remains unknown if the effects upon posterior airway space remain stable, and if a resulting posterior airway space enlargement may have clinical influence upon obstructive sleep apnoea syndrome.

Verification of mechanical load generated by functional orthodontic appliances

Functional appliances are widely used for promoting mandibular growth by utilizing a construction bite position. We aimed to measure the mechanical load generated by movement of functional appliances and determine the factors influencing this load. Thirteen patients aged 8-12 years were selected for the study, and the load was measured using a previously developed measurement device. To investigate the factors affecting the load, the temporomandibular joint morphology and muscles related to the mandible were examined using cone-beam computed tomography. The standard regression coefficients of the factors affecting the load per millimeter of movement distance were 0.64 and 0.66 for (a) the inclination of the articular eminence and (b) the angle between occlusal plane and posterior temporalis, respectively. Measurement of the occlusal plane to the posterior temporalis and the inclination of the articular eminence were significantly different (p < 0.05). The angle of inclination of the articular eminence emerged as a strong influencing factor. Similarly, the influence of measurements from the occlusal plane to the posterior temporalis was considerable since the posterior temporalis muscle is the most active when the mandible is extended forward. We also found a possible relationship between the occlusal force and load at the construction bite position. To our knowledge, this is the first study to determine the actual load associated with the angle of the temporalis muscle to the occlusal plane, inclination angle of the articular eminence, angle between the occlusal plane and the Frankfort plane, and the angle between the geniohyoid muscle and the occlusal plane. Therefore, mechanical considerations need to be more accurate to facilitate safe orthodontic treatment.

Orthopedic Treatment for Class II Malocclusion with Functional Appliances and Its Effect on Upper Airways: A Systematic Review with Meta-Analysis

Aim of this systematic review was to assess the effects of orthopedic treatment for Class II malocclusion with Functional Appliances (FAs) on the dimensions of the upper airways. Eight databases were searched up to October 2020 for randomized or nonrandomized clinical studies on FA treatment of Class II patients with untreated control groups. After duplicate study selection, data extraction, and risk of bias assessment according to Cochrane guidelines, random effects meta-analyses of mean differences (MDs) and their 95% confidence intervals (CIs) were performed, followed by subgroup/meta-regression analyses and assessment of the quality of evidence. A total of 20 nonrandomized clinical studies (4 prospective/16 retrospective) including 969 patients (47.9% male; mean age 10.9 years) were identified. Orthopedic treatment with FAs was associated with increased oropharynx volume (MD = 2356.14 mm³; 95% CI = 1276.36 to 3435.92 mm³; p < 0.001) compared to natural growth. Additionally, significant increases in nasopharynx volume, minimal constricted axial area of pharyngeal airway, and airway were seen, while removable FAs showed considerably greater effects than fixed FAs (p = 0.04). Finally, patient age and treatment duration had a significant influence in the effect of FAs on airways, as had baseline matching and sample size adequacy. Clinical evidence on orthopedic Class II treatment with FAs is associated with increased upper airway dimensions. However, the quality of evidence is very low due to methodological issues of existing studies, while the clinical relevance of increases in airway dimensions remains unclear.

Three-Dimensional Assessment of Mandibular Condylar Volume and Position Subsequent to Twin Block Functional Therapy of Skeletal Class II Malocclusion Accompanied by Low-Level Laser Therapy

This study aimed to evaluate and compare the effect of low-level laser therapy (LLLT) on mandibular condylar volume and position following treatment of a Class II malocclusion with a twin block (TB) appliance employing cone beam computed tomography (CBCT). Twenty-four growing patients, aged 9–12 years, were randomly allocated into control and laser groups. All patients were treated with a TB appliance. The patients in the laser group were treated weekly with a gallium–aluminum–arsenide (GaAlAs) diode laser around the temporomandibular joint (TMJ) region for three months. CBCT images were obtained before and after TB therapy and the changes in TMJ and skeletal variables were evaluated and compared among and between the groups. In the laser group, the condylar volume of the right and left sides significantly increased by 213.3 mm³ and 231.2 mm³, respectively (p < 0.05), whereas in the control group it significantly increased by 225.2 mm³, and 244.2 mm³, respectively (p < 0.05), with forward and lateral positioning of both sides. Furthermore, effective mandibular, ramus, and corpus lengths were increased, which were not significant between the groups. Low-Level Laser therapy accomplished no considerable effect on mandibular condylar volume and position following the functional orthopedic treatment of skeletal Class II malocclusions using a TB appliance.

Duration of orthodontic treatment with fixed appliances in adolescents and adults: a systematic review with meta-analysis

OBJECTIVES

Adults with fixed orthodontic appliances are increasing nowadays. Compared with adolescents, adults present biological differences that might influence treatment duration. Therefore, the aim of the study was to compare duration of treatment with fixed appliances between adults and adolescents.

MATERIALS AND METHODS

Eight databases were searched up to September 2019 for randomized and non-randomized clinical studies comparing treatment duration with fixed appliances in adolescents and adult patients. After duplicate study selection, data extraction, and risk of bias assessment with the Cochrane ROBINS-I tool, random effects meta-analyses of mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by assessment of the quality of evidence with GRADE.

RESULTS

A total of 11 unique studies (one prospective and 10 retrospective non-randomized) with 2969 adolescents and 1380 adult patients were finally included. Meta-analysis of 7 studies found no significant difference in the duration of comprehensive treatment with fixed appliances (MD = - 0.8 month; 95% CI = - 4.2 to 2.6 months; P = 0.65; I2 = 92%) between adults and adolescents. Similarly, both distalization of upper first molars with skeletal anchorage for class II correction and the retraction of canines into the premolar extraction spaces lasted similarly long among adults and adolescents. On the other hand, alignment of palatally displaced canines lasted considerably longer in adults compared to adolescents (1 study; MD = 3.8 months; 95% CI = 1.4 to 6.2 months; P = 0.002). The quality of evidence for the meta-analysis was low due to the inclusion of non-randomized studies with considerable risk of bias.

CONCLUSIONS

While existing evidence does not indicate a difference in the overall duration of treatment with fixed appliances between adults and adolescents, the alignment of palatally displaced canines lasted significantly longer in adults. However, our confidence in these estimates is low due to the risk of bias in the included studies.

TRIAL REGISTRATION

PROSPERO: ( CRD42019148169 ).

Comparison of facial soft tissue changes after treatment with 3 different functional appliances

INTRODUCTION

This study aimed to evaluate the effects of 3 different fixed or removable functional appliances on the soft tissue changes in patients with Class II Division 1 malocclusion using 3-dimensional images.

METHODS

A total of 60 patients with Class II Division 1 malocclusion (38 girls and 22 boys; mean age, 12.35 ± 1.01 years) were treated with 3 different functional appliances, namely, Twin-block (TB) (group TB, n = 20), mono-block (MB) (group MB, n = 20), or Herbst (H) (group H, n = 20) for 9.55 ± 1.46 months. Three-dimensional photographs of each patient were taken at the baseline and the end of the therapy with a 3dMD Face system (3dMD, Atlanta, Ga). Statistical analyses were performed using the dependent samples t test, 1-way analysis of variance, Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed rank tests.

RESULTS

No statistically significant differences were detected for soft tissue changes except for the lower facial width found, at least in group H (P <0.05). Volumetric differences in the mandible were similar between the groups (P >0.05). A statistically significant decrease in total facial height and an increase in convexity angle and facial depth were detected in all groups after treatment compared with the baseline (P <0.05). The upper and lower facial height, lower lip height, and nasal width were statistically significantly increased in the TB and MB groups after treatment compared with the baseline (P <0.05) and similar to those in group H (P >0.05).

CONCLUSIONS

TB, MB, and H appliances may promote the facial soft tissue profile, including volumetric improvement, in the mandibular region.

Post-treatment cephalometric changes in adolescent patients with Class II malocclusion treated using two different functional appliance systems for an extended time period: a randomized clinical trial

OBJECTIVES

To assess the post-treatment changes in Class II adolescent patients treated with two different functional appliances for an extended time period.

DESIGN

Randomized clinical trial.

SETTING

One university and one district general hospital in the UK.

PARTICIPANTS

Caucasian adolescent patients with a Class II malocclusion.

METHODS

Pairs of patients of similar age and gender were randomly allocated to one of two functional appliance systems, the Twin Block or Dynamax appliance. The appliances were used for 15 months full time. Changes were measured from lateral cephalograms taken at the start (T1) and at the end of treatment at 15 months (T2) and 30 months (T3).

RESULTS

Hundred patients completed the trial, 52 Twin Block and 48 Dynamax. Mandibular forward movement was 3.5 mm (±2.5) in the Twin Block group and 1.7 mm (±2.1) in the Dynamax group (P < 0.01; T1-T2) and, subsequently, by 0.3 mm (±2.6) and 0.9 mm (±2.5), respectively (P = 0.3; T2-T3). Mandibular length increased by 6.3 mm (±2.7) in the Twin Block group and 4.0 mm (±2.5) in the Dynamax group (P < 0.01; T1-T2) with treatment and, subsequently, by 0.5 mm (±2.3) and 1.5 mm (±3.1; P = 0.05). Anterior face height increased in both groups.

CONCLUSIONS

Treatment resulted in greater mandibular growth with the Twin Block than the Dynamax. In the follow-up period, there was less growth in the Twin Block group compared to the Dynamax.

TRIAL REGISTRATION

This trial was not registered on any major database of clinical trial.

PROTOCOL

The protocol was not published before the commencement of the trial but can be given on request.

Time of maxillary molar distalization with non-compliance intraoral distalizing appliances: a meta-analysis

BACKGROUND/OBJECTIVE

To assess the mean maxillary molar distalization time with non-compliance intraoral distalizing appliances.

SEARCH METHODS AND SELECTION CRITERIA

Database search included PubMed, Web of Science, Scopus, The Cochrane Library, Lilacs, and a partial grey literature through Google Scholar and OpenGrey. The search was performed until May 2017 and updated on February 2019, without limitations regarding publication year or language. Controlled clinical trials (randomized and non-randomized prospective studies) reporting duration of maxillary molar distalization of Class II patients treated with intraoral distalizers were included.

DATA COLLECTION AND ANALYSIS

For the trials' quality assessment, the Cochrane Risk of Bias tool and the Cochrane Collaboration's ROBINS-I tool were used for the randomized controlled trials and non-randomized prospective studies, respectively. Database research, risk of bias (RoB) assessment, and extraction of data were performed by two independent investigators, with inclusion of a third reviewer, if disagreements emerged. Data was combined through a random-effects meta-analysis. Subgroup analyses regarding side of force application, type of anchorage, amount of molar distalization, and sensitivity analysis comparing study designs were also performed. Quality of evidence was assessed using the GRADE and SORT approaches.

RESULTS

Nine studies were included in the qualitative analysis; however, a meta-analysis was performed with only four studies, due to the presence of high RoB in the other studies. The random-effects meta-analysis assumes that the mean distalization time with distalizers is 8.34 months (95% confidence interval: 6.10, 10.58). Another meta-analysis was performed to evaluate the relationship between distalization time and the type of anchorage (conventional or skeletal), resulting in no significant difference. Both meta-analyses presented low-quality evidence.

LIMITATIONS

The major limitation of this meta-analysis is the fact that distalization time can be affected by a great range of factors.

CONCLUSIONS AND IMPLICATIONS

Correction of a half-to-full cusp Class II molar relationship with intraoral distalizers can be achieved in 8.34 months, and this distalization time may not be affected by the kind of anchorage used.

REGISTRATION

The protocol for this systematic review was based on the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0 and was registered at PROSPERO database (http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42017068737). This systematic review is reported according to the PRISMA statement.

Skeletally anchored forsus fatigue resistant device for correction of Class II malocclusions-A systematic review and meta-analysis

The use of skeletal anchorage with fixed functional appliances (FFA) has been proposed by various authors to produce skeletal changes and reduce lower incisor proclination. To compare the skeletal and dentoalveolar effects of Forsus Fatigue Resistant Device (FFRD) with or without skeletal anchorage (miniplates and mini-implants). The electronic database PubMed, Cochrane Library, Medline, Embase and Google Scholar along with a manual search of orthodontic journals till the year 2019. Only randomized control trials (RCTs) were included in the systematic review. One controlled clinical trial (CCT) which involved FFRD was included in the review since it was a continuation of an RCT which was expanded to a CCT. Skeletal and dentoalveolar outcome data were extracted to collect study characteristics. After evaluating risk of bias, the standardized mean differences (SMDs) and 95% confidence intervals (CIs) were calculated. Three RCTs and one prospective CCT were evaluated. The analysis included data from 116 Class II subjects [(58) treated with FFA along with skeletal anchorage and (58) treated with FFA]. There were no significant difference between the two groups with respect to mandibular length changes (P value = .10) and SNB angle changes (P value = .22). With respect to lower incisor inclination however, there was a significant difference between the two groups (P value = .005) signifying better results with respect to skeletal anchorage. The studies reviewed provide insufficient evidence to form a conclusion regarding the effects of the use of skeletal anchorage with FFRD. The available weak evidence suggests that the use of skeletal anchorage with FFRD has no superior skeletal effects but is able to reduce proclination of the lower incisors. Control of lower incisor proclination remains the most significant advantage of skeletal reinforcement, and miniplate-anchored FFRD showed more promising results in preventing lower incisor proclination than miniscrew-anchored FFRD.