Soft tissue evaluation of functional therapy in growing patients with Class II malocclusion: a long-term study.
Gazzani Francesca,Franchi Lorenzo,Lione Roberta,Cozza Paola,Pavoni Chiara
European journal of orthodontics
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.
10.1093/ejo/cjab008
Treatment efficiency of activator and skeletal anchored Forsus Fatigue Resistant Device appliances.
Ince-Bingol Sinem,Kaya Burcak,Bayram Burak,Arman-Ozcirpici Ayca
Clinical oral investigations
OBJECTIVES:The aim of the study was to investigate the treatment efficiency of miniplate anchored Forsus Fatigue Resistant Device (MAF) as compared with the activator appliance. MATERIALS AND METHODS:Mandibular retrognathia was treated with two methods, the MAF group (8 girls, 11 boys, mean age 13.03 ± 0.69 years) and the activator group (7 girls, 12 boys, mean age 12.68 ± 0.73 years). An untreated control group (9 girls, 10 boys, mean age 12.95 ± 0.73 years) was constructed to eliminate growth-related changes through the American Association of Orthodontists Foundation Legacy Collection. Data of 114 lateral cephalograms were analyzed. RESULTS:The inhibition of the maxillary growth was greater in the MAF group, whereas forward displacement of the mandible was higher in the activator group (P < 0.05). Sagittal maxillomandibular relation was improved similarly in both treatment groups (P < 0.05). Mandibular length was increased in both treatment groups with the highest increase in the activator group (P < 0.05). Retroclination of the incisors was observed in the MAF group (P < 0.05). The upper lip was retruded in the MAF group and lower lip was protruded in the activator group (P < 0.05). CONCLUSION:The activator created greater mandibular changes, whereas the MAF provides somewhat smaller mandibular changes due to the restriction caused by retroclined maxillary incisors. CLINICAL RELEVANCE:Although both MAF and activator treatments caused favorable maxillomandibular changes, new treatment alternatives that reduce dentoalveolar side effects and eliminate patient cooperation are still required to achieve skeletal correction in class II malocclusion treatment in growing patients.
10.1007/s00784-020-03458-3
Evaluation of growth changes induced by functional appliances in children with Class II malocclusion: Superimposition of lateral cephalograms on stable structures.
Korean journal of orthodontics
OBJECTIVE:To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. METHODS:Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. RESULTS:Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion- pogonion, < 0.001), maxillary prognathism (sella-nasion-subspinale, < 0.05), and condylar growth ( < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction ( < 0.001) and decreased overjet ( < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 ( < 0.01). The improvements in the sagittal jaw relationship ( < 0.01) and dental relationship ( < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. CONCLUSIONS:Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.
10.4041/kjod.2020.50.3.170
Evaluation of the Oropharyngeal Airway Space in Class II Malocclusion Treated with Mandibular Activator: A Retrospective Study.
Cortese Marina,Pigato Giada,Casiraghi Giulia,Ferrari Maurizio,Bianco Edoardo,Maddalone Marcello
The journal of contemporary dental practice
AIM:The development of a class II malocclusion is usually related to a reduced oropharyngeal airway space. In order to prevent airway obstruction, functional appliances are commonly used for orthodontic therapy. The aim of the article is to verify if these appliances could positively influence oropharyngeal diameters preventing the onset of future respiratory disorders. MATERIALS AND METHODS:A group of 10 patients treated at the Dental Clinic of San Gerardo Hospital in Monza with mandibular activator was selected. Ten similar untreated class II subjects with retrognathic mandible were used as control group. The cephalometric tracings were made on lateral teleradiographs of the skull before and after the active therapy with functional devices for the treated group and before and after growth peak for the control one. Descriptive statistical analysis was calculated for all the cephalometric values in both study cases and control group using Excel worksheet. The data distribution was evaluated with Shapiro-Wilk test and the in-between group discrepancies were evaluated with Mann-Whitney test. RESULTS:At T1 period, both case and control groups showed a class II pattern. At T2 period, the study group shows an improvement in bones relationship with reduced ANB angles and OVJ measurements. The control group otherwise did not show any important changes in maxillo-mandibular discrepancies. The airway size increased in either group in most cases. No significant differences between the treated and control groups were detected for airway size neither in the upper, middle, nor lower level at the T1-T2 interval. CONCLUSION:The upper airway values did not show any significant discrepancies between the two groups during the observation period. CLINICAL SIGNIFICANCE:Functional devices were effective in solving class II relationships, but there is no evidence of successful breathing disorders prevention by using mandibular activators, probably due to the stability of airway tissues reached in pubertal age in both groups.
Early headgear activator treatment of Class II malocclusion with excessive overjet: a randomized controlled trial.
Kallunki Jenny,Bondemark Lars,Paulsson Liselotte
European journal of orthodontics
OBJECTIVES:To compare early headgear activator treatment of Class II malocclusion with excessive overjet with untreated control subjects in terms of the primary outcomes overjet and overbite as well as the effect regarding oral-health-related quality of life (OHRQoL), lip closure, incidence of trauma, and skeletal changes. TRIAL DESIGN:Two-arm parallel group single-centre randomized controlled trial. MATERIAL AND METHODS:A total of 60 children (mean age 9.5 years) presenting a Class II malocclusion with excessive overjet were recruited. The trial was designed as intention-to-treat and the participants randomized by an independent person not involved in the trial to either early treatment with headgear activator or to an untreated control group (UG). Dental and skeletal variables as well as registrations of OHRQoL, lip closure, and incidence of trauma were recorded. For the treatment group, data were registered at baseline before treatment and when treatment was finished, corresponding to approximately 2 years. For the UG, registrations were made at baseline and at 11 years of age. Observers were blinded to treatment allocation when assessing outcomes. RESULTS:Early treatment with headgear activator significantly decreased overjet and improved molar relationship when compared with untreated controls. The effects were primarily due to dentoalveolar changes. Early treatment had no evident effect regarding OHRQoL, lip closure, or incidence of trauma. Lack of cooperation resulted in unsuccessful treatments for 27% of the patients. LIMITATIONS:The trial was a single-centre trial and can thus be less generalizable. CONCLUSIONS:The main treatment effect of early headgear activator treatment of Class II malocclusion with excessive overjet is reduction of overjet. TRIAL REGISTRATION:NCT04508322.
10.1093/ejo/cjaa073
Soft- and hard-tissue changes following treatment of Class II division 1 malocclusion with Activator versus Trainer: a randomized controlled trial.
Idris Ghassan,Hajeer Mohammad Y,Al-Jundi Azzam
European journal of orthodontics
Background:Increased awareness on the role of oral functions in the aetiology of Class II deformities has led to the wide spread of myofunctional training appliances as easy and possibly effective treatment for children with Class II malocclusion but their efficacy is yet to be proven. Objectives:To evaluate soft- and hard-tissue changes following 12 months of Class II division 1 treatment in growing patients with a conventional functional appliance (a modified Activator) versus a myofunctional Trainer system (T4K®). Setting and sample population:Department of Orthodontics, Dental School. Participants, study design, and methods:Sixty Class II division 1 children (8-12 years old) were recruited from primary schools and were distributed randomly into two equal groups. Randomization was based on a computer-generated sequence of random numbers. Data analysis included: the Activator group (28 patients, mean age = 10.6 ± 1.3 years); the T4K® group (26 patients, mean age = 10.3 ± 1.4 years). Skeletal, dentoalveolar, and soft tissues changes were assessed using standardized lateral cephalograms collected before and after 12 months of treatment. No blinding was applied in this trial. Results:Improvement in the Class II skeletal and dentofacial characteristics were significantly greater in the Activator group when compared with the T4K® group. The improvement was evident in a significant decrease in the skeletal angle ANB with Activator (x¯ = -1.89 ± 1.12) compared to T4K® (x¯ = -0.9 ± 1.01) (P = 0.01), a significant greater increase in the facial convexity angle with Activator (x¯ = 2.61 ± 3.71) more than T4K® (x¯ = 0.2 ± 2.51) (P = 0.04), and a significant reduction in the overjet (x¯ = -3.0 ± 2.3 mm) compared to (x¯ = -1.5 ± 1.9 mm; P = 0.01) with Activator versus T4k®, respectively (P = 0.001). Limitations:This study was a short-term study (12-month follow-up). Conclusions:The results of the current study indicated that the Activator was more effective than the T4K® in treating Class II division 1 growing patients. Registration:The trial was not registered in any major database of clinical trials. Protocol:The protocol was not published before the commencement of the trial but can be given upon request.
10.1093/ejo/cjy014
Effects of orthodontic treatment with activator appliance on patients with skeletal Class II malocclusion: a systematic review and meta-analysis.
Xie Jiye,Huang Chunrong,Yin Kang,Park Juyoung,Xu Yanhua
Annals of palliative medicine
BACKGROUND:This systematic review aimed to evaluate and compare the treatment effects of activator appliances on untreated class II skeletal malocclusion patients in terms of skeletal, dental, and soft tissue changes. METHODS:We searched 11 databases from January 1966 to May 2021 for randomized and clinical controlled trials that compared the treatment effects of activator appliances on untreated Class II skeletal malocclusion patients. All data were analyzed using RevMan 5.3 software. RESULTS:According to the inclusion/exclusion criteria, 16 articles qualified for the final analysis. Thirteen outcome indicators of teeth, bone tissue, and soft tissue were compared and analyzed: SNA°, SNB°, ANB°, SN-MP°, ANS-Me, Co-Gn, Go-Me, overjet, overbite, U1-SN°, L1-MP°, UL-E, and LL-E. Five randomized controlled trials (RCTs) evaluations were of medium quality, and 11 controlled clinical trials (CCTs) evaluations were of B grade. Bone tissue changes: compared with the untreated group, the SNA and ANB decreased, and the SNB, SN-MP, ANS-Me, Co-Gn, and Go-Me increased after activator appliance treatment, and the differences were statistically significant (P<0.001). Dental changes: compared with the untreated group, the overjet, overbite and U1-SN in the treated group decreased significantly, while the L1-MP increased significantly (P<0.0001). Soft tissue changes: compared with untreated patients, the UL-E of patients treated with an activator appliance decreased significantly (P<0.0001); however, there was no significant difference in the LL-E between the two groups (P=0.09). DISCUSSION:Since the imprecision and high level of heterogeneity of the articles, further large-sample and high-quality clinical trials are necessary to evaluate effects of orthodontic treatment with activator appliance on patients with skeletal Class II malocclusion. In addition, this study failed to explore the long-term stability of activator treatment, so long-term studies are needed to assess the stability of its effect on the skeletal, dental, and soft tissue changes.
10.21037/apm-21-3205
Comparison of skeletal and dentoalveolar effects of two different mandibular advancement methods: conventional technique vs aesthetic approach.
European oral research
Purpose:The aim of this study was to compare the effects of two different mandibular advancement methods on skeletal, dentoalveolar, and soft tissue structures through cephalometric measurements. Materials and methods:The aim of this study was to compare the effects of two different mandibular advancement methods on skeletal, dentoalveolar, and soft tissue structures through cephalometric measurements. Results:The mandibular base was observed to move forward significantly in both groups (p<0.05). However, the forward movement of the mandibular base was greater in the TB group than in the EA group (p<0.05). There was no difference in lower incisor protrusion between the two treatment methods. The EA device was found to cause a significant increase in vertical direction parameters (p<0.05). Conclusion:Both methods resulted in Class II malocclusion correction as well as an acceptable occlusion plus profile. The effects of EA were primarily dentoalveolar. In patients with high aesthetic expectations, EA could be an alternative for TB.
10.26650/eor.2022939871
A systematic review of the accuracy and efficiency of dental movements with Invisalign®.
Galan-Lopez Lidia,Barcia-Gonzalez Jorge,Plasencia Eliseo
Korean journal of orthodontics
We are currently living in an era where the use of computer-aided design/computer-aided manufacturing has allowed individualized orthodontic treatments, but has also incorporated enhanced digitalized technology that does not permit improvisation. The purpose of this systematic review was to analyze publications that assessed the accuracy and efficiency of the Invisalign® system. A systematic review was performed using a search strategy to identify articles that referenced Invisalign®, which were published between August 2007 and August 2017, and listed in the following databases: MEDLINE, Embase, Cochrane Library, Web of Knowledge, Google Scholar, and LILACS. Additionally, a manual search of clinical trials was performed in scientific journals and other databases. To rate the methodological quality of the articles, a grading system described by the Swedish Council on Technology Assessment in Health Care was used, in combination with the Cochrane tool for risk of bias assessment. We selected 20 articles that met the inclusion criteria and excluded 5 due to excess biases. The level of evidence was high. Although it is possible to treat malocclusions with plastic systems, the results are not as accurate as those achieved by treatment with fixed appliances.
10.4041/kjod.2019.49.3.140
Efficacy of clear aligners in controlling orthodontic tooth movement: a systematic review.
Rossini Gabriele,Parrini Simone,Castroflorio Tommaso,Deregibus Andrea,Debernardi Cesare L
The Angle orthodontist
OBJECTIVE:To assess the scientific evidence related to the efficacy of clear aligner treatment (CAT) in controlling orthodontic tooth movement. MATERIALS AND METHODS:PubMed, PMC, NLM, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Knowledge, Scopus, Google Scholar, and LILACs were searched from January 2000 to June 2014 to identify all peer-reviewed articles potentially relevant to the review. Methodological shortcomings were highlighted and the quality of the studies was ranked using the Cochrane Tool for Risk of Bias Assessment. RESULTS:Eleven relevant articles were selected (two Randomized Clinical Trials (RCT), five prospective non-randomized, four retrospective non-randomized), and the risk of bias was moderate for six studies and unclear for the others. The amount of mean intrusion reported was 0.72 mm. Extrusion was the most difficult movement to control (30% of accuracy), followed by rotation. Upper molar distalization revealed the highest predictability (88%) when a bodily movement of at least 1.5 mm was prescribed. A decrease of the Little's Index (mandibular arch: 5 mm; maxillary arch: 4 mm) was observed in aligning arches. CONCLUSIONS:CAT aligns and levels the arches; it is effective in controlling anterior intrusion but not anterior extrusion; it is effective in controlling posterior buccolingual inclination but not anterior buccolingual inclination; it is effective in controlling upper molar bodily movements of about 1.5 mm; and it is not effective in controlling rotation of rounded teeth in particular. However, the results of this review should be interpreted with caution because of the number, quality, and heterogeneity of the studies.
10.2319/061614-436.1
Three-Dimensional Evaluation of Soft Tissue Changes after Functional Therapy.
Yıldırım Ersin,Karaçay Şeniz,Tekin Dilek
Scanning
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 test. In this study, a decrease was observed in SNA ( < 0.05), ANB ( < 0.01), and NV-Pog ( < 0.05) while an increase in SNB ( < 0.01) was found. However, decrease in NV-A distance was not statistically significant ( > 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 ( < 0.01, < 0.01, and < 0.05, respectively), the upper lip and subnasale repositions were not statistically significant ( > 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.
10.1155/2021/9928101
Changes in the upper airway, hyoid bone and craniofacial morphology between patients treated with headgear activator and Herbst appliance: A retrospective study on lateral cephalometry.
Gu Min,Savoldi Fabio,Chan Eliza Y L,Tse Christine S K,Lau Michelle T W,Wey Mang C,Hägg Urban,Yang Yanqi
Orthodontics & craniofacial research
BACKGROUND:The present study compared the treatment changes in the upper airway, hyoid bone position and craniofacial morphology between two groups of children with skeletal class II malocclusion treated with the headgear activator (HGA) and Herbst appliance (Herbst). SETTING AND SAMPLE POPULATION:Orthodontic population from the Faculty of Dentistry of the University of Hong Kong. METHODS:Thirty-four skeletal class II patients treated with the HGA (17 patients, mean age 10.6 ± 1.5 years) and the Herbst (17 patients, mean age 11.0 ± 1.4 years) were matched for sex, age, overjet, skeletal class and mandibular divergence. The patients received lateral cephalometric radiographs (LCRs) at the beginning of treatment (T ), after treatment (T ) and at follow-up (T ). In the HGA group, patients underwent LCRs 7 months before the beginning of treatment (T ), which were used as growth reference for intra-group comparison. Paired Student's t tests were used for intra- and inter-group comparisons (α = .05). RESULTS:Treatment changes (T -T ) did not differ significantly between the groups. However, at follow-up (T -T ) the Herbst group showed a smaller increase than the HGA group in the vertical position of the hyoid bone relative to the Frankfort plane (P = .013) and mandibular plane (P = .013). CONCLUSIONS:There were no significant differences in the upper airway, hyoid bone position and craniofacial morphology between the groups at the end of treatment. However, the Herbst may provide better long-term control of the vertical position of the hyoid bone than the HGA in children with skeletal class II malocclusion.
10.1111/ocr.12442
Comparison of facial soft tissue changes after treatment with 3 different functional appliances.
Güler Özge Çelik,Malkoç Sıddık
American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics
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.
10.1016/j.ajodo.2019.06.020
Orthodontic Management of Skeletal Class II Malocclusion with the Invisalign Mandibular Advancement Feature Appliance: A Case Report and Review of the Literature.
Case reports in dentistry
The treatment of Class II malocclusion due to mandibular retrognathia is one of the most common challenges met in orthodontic practice. When it comes to a growing patient, functional appliances are the optimal way to achieve growth modification by enhancing mandibular growth. Clear aligners have been part of the orthodontic treatment for several decades but until recently they were only used to correct mild malocclusions. In 2017, Align Technology introduced the Invisalign with Mandibular Advancement Feature (IMAF) which replicates the action of functional appliances. As this device is new to clinical practice, there is limited literature on its clinical efficiency. This case report describes the orthodontic management of a 12-year-old male patient having skeletal Class II malocclusion due to mandibular retrognathia. As the patient was experiencing active growth, the IMAF appliance was chosen for his treatment. The IMAF appliance appears to be successful in the treatment of Class II malocclusion with mandibular retrognathism in a growing patient. As with all functional appliances, the correction of the malocclusion is a result of both skeletal and dental effects and the IMAF presents the advantage of producing less proclination of the lower incisors compared to other functional appliances.
10.1155/2022/7095467
Short term dentoskeletal effects of mandibular advancement clear aligners in Class II growing patients. A prospective controlled study according to STROBE Guidelines.
Ravera S,Castroflorio T,Galati F,Cugliari G,Garino F,Deregibus A,Quinzi V
European journal of paediatric dentistry
AIM:To evaluate the dentoskeletal effects of the Invisalign® Mandibular Advancement (MA) (Align Technology, San José, CA, USA) feature in skeletal Class II growing patients with mandibular retrusion, at pre-pubertal and pubertal stages. MATERIALS AND METHODS:Study design: Forty skeletal Class II patients were prospectively recruited and treated with Invisalign® MA. They were divided into two subgroups according to the CVM stage of growth (CVM2 and CVM3) at the beginning of treatment (T0). For each patient, lateral radiographs were collected at the beginning (T0) and at the end of the mandibular advancement treatment (T1) and their measurements were compared with those obtained by an untreated control group of 32 subjects, matched for growth stage and malocclusion. RESULTS:Patients in CVM2 showed significant reduction of ANB angle, A:Po, Wits index, 11^Spp angle and significant increase of 11^41 and B Downs point. In CVM3 significant reduction of the Wits index and of 41^GoGn angle, and significant increase of the linear Co-Gn measurement, were revealed. STATISTICS:The STROBE guidelines were followed. Linear regression analysis was performed to estimate the differences of ? (T1 - T0) means between group (control was used as reference) stratifying by CVM levels. CONCLUSION:The use of Invisalign® MA is effective in treating Class II growing patient with retrognathic mandible in the short term period. While treatment at prepubertal stage of growth results in dentoalveolar rather than skeletal effects, treatment during the pubertal spurt produces skeletal effects with an annual rate of change of 5.8 mm.
10.23804/ejpd.2021.22.02.6
Mandibular advancement with clear aligners in the treatment of skeletal Class II. A retrospective controlled study.
Caruso S,Nota A,Caruso S,Severino M,Gatto R,Meuli S,Mattei A,Tecco S
European journal of paediatric dentistry
AIM:The current study aimed to analyse the dentoskeletal effects of the Invisalign mandibular advancement (MA) device in the treatment of skeletal Class II malocclusions. MATERIALS AND METHODS:Pre-treatment and post-treatment lateral skull radiographs from patients treated with MA versus TB (Twin-Block Appliance) at the Department of Orthodontics of the University of L'Aquila, Italy, were traced. Eligibility criteria included SNB<78; ANB>4; no previous orthodontic treatments; and vertebral maturation stage (CVM) CS3. Radiographs from patients with craniofacial anomalies, or who underwent extraction treatments, were excluded. Totally, 20 patients were examined, 10 of whom treated with MA and 10 treated with TB. All the radiographs were traced by one expert operator, blind to the groups. A preliminary method error study was performed to exclude intra-operator differences. RESULTS:Baseline characteristics of the participants were similar between the groups. Both appliances demonstrated a reduction of SNB and ANB angle, and a decrease in overjet. TB demonstrated a higher efficacy in increasing mandibular dimensions. A significant retroinclination of the upper incisive was observed in the TB group, where a decrease of SNA angles was additionally observed. The resulting differences between the two groups could be attributed to the different design of the appliances. CONCLUSIONS:The present data show the effectiveness of both TB and MA in the management of skeletal Class II malocclusions due to mandibular retrusion. But some differences exist in the dentoalveolar effect of the two appliances. MA seems indicated in Class II cases where a control of the upper frontal teeth position is needed.
10.23804/ejpd.2021.22.01.05
Comparison of the effects of rapid maxillary expansion versus Twin Block appliance on mandibular growth in skeletal Class II patients.
Zhang Jia-Nan,Chen Si,Huang Cheng-Yi,Zhong Chong,Jin Jing,Yu Feng-Yang,Zhang Zan-Zan,Lu Hai-Ping
BMC oral health
BACKGROUND:This is a retrospective study that compares mandibular growth changes in skeletal Class II patients treated by rapid maxillary expansion (RME) and following fixed appliance with those patients treated by Twin-Block (TB) and following fixed appliance. METHODS:Fourteen patients treated by RME and following fixed appliance were included into the RME group. Fifteen patients treated by Twin-Block and following fixed appliance were included into the TB group. Lateral cephalometric radiographs taken before treatment and immediately after fixed appliance treatment were used to evaluate mandibular growth effects. RESULTS:The starting forms of the patients in the two groups were examined to be of good comparability. The mandibular length increased significantly in both groups as measured by Co-Gn, Go-Gn and Ar-Gn, but the TB group didn't show more mandibular growth than the RME group (P > 0.05). Skeletal changes of the mandible in vertical dimension were different in the two groups. The change in FMA was 0.35° in the RME group, while the change was 2.65° in the TB group (P < 0.001). The change in LAFH was 5.14 mm in the RME group, significantly smaller than the change of 10.19 mm in the TB group (P < 0.001). CONCLUSION:The investigated Phase I treatment with RME followed by Phase II treatment of fixed appliance achieved the same increases in sagittal mandibular growth and facial profile improvements as the Twin-Block therapy. The treatment with RME followed by fixed appliance was better for vertical control, while the treatment with Twin-Block followed by fixed appliance significantly increased the mandibular plane angle.
10.1186/s12903-020-01344-8
Comparison of cephalometric measurements of the Twin Block and A6 appliances in the treatment of Class II malocclusion: a retrospective comparative cohort study.
Annals of translational medicine
Background:Skeletal Class II malocclusion is a common malocclusion that seriously affects patients' profile and occlusal function. The key to treatment is to use functional appliances guide the mandible forward. This study aimed to evaluate the clinical efficacy of traditional functional appliance Twin Block (TB) and invisible functional appliance (A6). Methods:In the retrospective cohort study, 46 patients with Class II Division 1 mandibular retrognathia (23 females, 23 males; mean age 13.66±4.25 years) from the Third Affiliated Hospital of Sun Yat-sen University were selected. They were divided into A6 group and TB group according to the type of appliance guided mandibular forward used in orthodontic treatment (n=23 each; average treatment time 9.82±3.52 months). Lateral cephalometric radiographs were taken before and at the end of each treatment, and paired -test or paired rank-sum tests were performed when appropriate to detect any statistical significance at the level of α=0.05. Results:The baseline characteristics of the two groups of patients were similar. Treatment with both appliances helped correct Class II malocclusion, improve the discrepancy between the maxilla and mandible, reduce the labial inclination of the maxillary anterior teeth, and relieve the deep overbite. A comparison of the treatment effects of the TB and A6 groups showed that the A6 had a better effect when moving Point A backward, and performed better in the abduction of the anterior teeth. TB group has more advantages than A6 group in moving forward point B and improving the nasolabial angle. Conclusions:Both the A6 and TB can significantly improve Class II malocclusion. A6 showed an obvious advantage in moving Point A backward and adducting the anterior teeth, which better corrects a skeletal Class II malocclusion.
10.21037/atm-22-3762