Class II subdivision treatment with the Forsus Fatigue Resistant Device vs intermaxillary elastics

Class II subdivision treatment and stability with asymmetric Herbst appliance: A case report

Non-surgical treatment of Class II subdivision may involve complex mechanics or asymmetric tooth extraction in its resolution. This report demonstrates the result and the short-term stability of Class II subdivision treated with asymmetrically installed Herbst appliance followed by conventional fixed orthodontic appliance. The approach allowed the correction of the unilateral Class II molar relationship and increased overjet, as well as the deviation of dental midlines, with improvement in lip posture and facial profile. The results remained stable two years after treatment, confirming the treatment success.

Comparative evaluation of the dentoalveolar effects of three Class II correctors: A finite element analysis study

OBJECTIVE

To compare the stress distribution and total strain applied to the dentition, periodontal ligament (PDL) and cortical and trabecular bones by three Class II correctors using finite element analysis.

DESIGN

Three-dimensional analysis of stresses and total strain of the dentition with three Class II correctors.

SETTING

Computational study.

METHODS

Three-dimensional finite element models of Class II elastics, the Forsus Fatigue Resistant Device (FRD) and the Carriere Motion Appliance (CMA) were constructed from a cone-beam computed tomography (CBTC) image of an orthodontic Class II patient. The distribution of stress (von Mises and principal stress) and the total strain (mm) in maxillo-mandibular dentition, PDL, cortical and trabecular bone were analysed.

RESULTS

The highest von Mises yield and the maximum principal stress in the three models were found at the teeth, followed by the cortical bone, trabecular bone and PDL. The maximum stress and total deformation were located at the upper canines and lower molars in the Class II elastics and CMA models, in the upper first molars in the Forsus FRD and CMA, and in the lower first premolars in the Forsus FRD. In addition, stress was distributed in the anterior and posterior regions of the teeth, and the total deformation was found in the distal direction in the upper arch and in the mesial direction in the lower arch.

CONCLUSION

The stress concentrations in the three models were located close to the active components of each appliance, producing specific patterns of stress distribution and displacement that should be taken into account when planning the type of appliance to be used for the correction of the Class II malocclusion.

Stability of class II correction with the Austro Repositioner associated with multi-brackets fixed appliances in dolichofacial patients

BACKGROUND

The purposes of the present study were to evaluate the changes produced by the Austro Repositioner, and to assess the stability of Class II malocclusion treatment with the Austro Repositioner associated with fixed appliances and its capacity to control the vertical dimension in dolichofacial patients.

METHODS

A group of patients with Class II malocclusion due to mandibular retrognathism and a dolichofacial growth pattern treated with the Austro Repositioner combined with fixed appliances were compared to a matched untreated control group of subjects with Class II malocclusion. Evaluations were made on the basis of lateral cephalograms taken at T1 (initial records), T2 (end of treatment), and T3 (1 year after treatment). Statistical comparisons were performed with paired- and two-sample t tests.

RESULTS

The experimental (treated) group comprised 30 patients, 14 boys and 16 girls, and the control group comprised 30 subjects (15 boys and 15 girls) with similar ages at T1, T2 and T3. In the treated group, a significant decrease in the ANB angle was found (- 3.79 ± 1.46; p < 0.001). No significant differences were found in the maxillary skeletal measurements. In contrast, the SNB angle showed a significant increase of 3.77 ± 1.49 in the treated group compared with a nonsignificant increase of 0.77 ± 1.55 in the control group (p = 0.002). Vertical changes showed a significant decrease in the FMA angle (- 3.36 ± 1.62), while the lower anterior facial height distance and the overbite increased significantly in the treated group, reflecting a change in vertical dimensions after treatment. No significant changes were observed in either the treated or control group during the one-year posttreatment period; thus, the treatment results remained stable.

CONCLUSIONS

The Austro Repositioner combined with fixed appliances could be considered an optimal treatment modality in Class II dolichofacial patients.

Influence of the force magnitude of fixed functional appliances for class II subdivision 1 treatment-a cephalometric study

PURPOSE

To investigate the skeletal and dental effects of a hybrid fixed functional appliance (FFA) used with different force magnitudes for class II subdivision 1 treatment.

METHODS

Treatment records from 70 patients were evaluated: 35 patients were treated with a FFA with standard activation (SUS group) and 35 with a FFA with an additional force-generating spring (TSUS group). Two control groups were matched from the American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection for comparison with the two treatment groups to determine skeletal and dental treatment effects. The cephalometric parameters at T0 (before treatment) and T1 (before debonding) were assessed using the Munich standard cephalometric analysis and by the sagittal occlusal analysis (SO) according to Pancherz. Data were analyzed statistically using SPSS.

RESULTS

No statistically significant difference for any cephalometric parameter was observed between the SUS and TSUS groups concerning the measurements at T0 and T1. Both treatment groups exhibited an effective class II therapy mainly due to a significant reduction in SNA, and ANB and an increase in SNB. In contrast to the control group, as the result of treatment a skeletal class I was achieved.

CONCLUSION

No significant statistical differences were observed between the patient group treated with the FFA with standard activation (SUS) and those treated with an additional spring (TSUS) regarding the cephalometric parameters investigated. Both variants were equally effective in treating class II division 1 malocclusions.

Stability of Class II malocclusion treatment with Class II elastics

INTRODUCTION

The objective of this study was to compare the long-term cephalometric stability after successful therapy of nonextraction Class II malocclusion with elastics and with headgear.

METHODS

The sample comprised 43 patients with Class II malocclusion and was divided into 2 groups. The elastic group (EG) consisted of 20 patients treated with fixed appliances associated with Class II elastics, and the headgear group (HG) consisted of 23 patients treated with fixed appliances and extraoral headgear. Pretreatment, posttreatment, and long-term posttreatment lateral radiographs were evaluated; t tests were used to compare the long-term posttreatment changes between the groups.

RESULTS

The groups were matched regarding initial age, time of long-term posttreatment evaluation, initial malocclusion severity, quality of treatment result, and all pretreatment cephalometric variables. Intergroup comparisons of long-term posttreatment changes showed that the HG group presented significantly greater mandibular protrusion, occlusal plane angle decrease, and maxillary molar mesialization. However, long-term posttreatment stability was similar in overjet, overbite, and molar relationships.

CONCLUSIONS

Nonextraction Class II malocclusion treatment with elastics or extraoral headgear have similar long-term posttreatment stability.

Class II Malocclusion in Adult Patients: What Are the Effects of the Intermaxillary Elastics with Clear Aligners? A Retrospective Single Center One-Group Longitudinal Study

Aim: To evaluate the dental effects of the treatment with clear aligners and intermaxillary elastics in adult patients with Class II malocclusion. Material and methods: A sample of 20 Class II patients treated with Invisalign aligners (5 M and 15 F; mean age of 27.6 ± 6.3 years) was included in this single-center one-group longitudinal study. Dental cast and cephalometric records were analyzed before (T0) and after treatment (T1). Data were analyzed with a t-test for paired data (p < 0.05). Results: There was a significant reduction of the Overjet (OVJ= −1.4 ± 0.2; p ≤0.001) and a retroposition of upper incisors (U1-NPo = −1.3 ± 1.7; p < 0.001). Furthermore, distalization of upper molars with an improvement of molar class (U6-PT Vertical = −0.93 ± 0.97; p < 0.001; Molar Relation = −0.75 ± 0.45; p < 0.001) was observed. A good control of the lower and upper incisor inclination was present, highlighted by the non-significant changes in these values (L1-GoGn = −0.12 ± 5.4; p = 0.923; U1-AnsPns = −1.1 ± 8.1; p = 0.551). In the lower arch, an increase in the intermolar diameter (0.6 ± 1.0; p = 0.01) was present. Finally, there were no statistically significant changes in all the skeletal variables (ANPg = 0.005 ± 0.687; p = 0.974; SN/MP = −0.47 ± 1.9; p = 0.298). Conclusions: Treatment with Invisalign aligners shows a reduction of the Overjet, a retroposition of the upper incisors, good control of the lower incisors, and an improvement of the molar relationship.

Dental and Skeletal Effects of Herbst Appliance, Forsus Fatigue Resistance Device, and Class II Elastics-A Systematic Review and Meta-Analysis

Background: Our study aimed to systematically summarize the dentoskeletal effects of Herbst appliance; Forsus fatigue resistance device; and Class II elastics in adolescent Class II malocclusion. Methods: Five databases; unpublished literature; and reference lists were last searched in August 2022. Randomized clinical trials and observational studies of at least 10 Class II growing patients that assessed dentoskeletal effects through cephalometric/CBCT superimpositions were eligible. The included studies quality was assessed with the RoB 2 and ROBINS-I tools. A random-effects model meta-analysis was performed. Heterogeneity was explored with subgroup and sensitivity analyses. Results: Among nine studies (298 patients); two-to-three studies were included in each meta-analysis. Less post-treatment upper incisor retroclination (<2) and no overbite; overjet; SNA; SNB; and lower incisor inclination differences were found between Herbst/Forsus and Class II elastics. No differences in maxilla; condyle; glenoid fossa; and most mandibular changes were found between Herbst and Class II elastics; except for a greater 1.5 mm increase in mandibular length and right mandibular ramus height (1.6 mm) with Herbst. Conclusions: Herbst and Class II elastics corrected the molar relationship; but Herbst moved the lower molars more mesially. Apart from an additional mandibular length increase; no other dental and anteroposterior skeletal difference was found. Forsus was more effective in molar correction; overjet reduction; and upper incisor control than Class II elastics. Trial registration number OSF: 10.17605/OSF.IO/8TK3R.

Biomechanical analysis of effective mandibular en-masse retraction using Class II elastics with a clear aligner: a finite element study

Background

This study aimed to evaluate the displacement and stress distribution of mandibular dentition by various positions of the Class II elastics during en-masse retraction in clear aligner therapy.

Methods

Models including a mandibular dentition (without first premolars), periodontal ligament (PDL), mandible, as well as attachments, aligners and buttons were constructed and imported into Ansys Workbench 2019 (ANSYS, USA) to generate the three-dimensional (3D) finite element model. Six combinations were created: (1) aligner alone (control), (2)-(5) Class II elastics with buttons placed on the mesiobuccal (MB), distobuccal (DB), mesiolingual (ML) and distolingual (DL) surface of the mandibular first molar, and (6) Class II elastics with a button on the aligner corresponding to the mesiobuccal surface of the mandibular first molar (AMB). The elastic force was set to 2 N for simulations.

Results

The central incisors appeared lingual tipping in the six models. The lingual crown movement of the central incisors was 0.039 mm, 0.034 mm, 0.034 mm, 0.042 mm, 0.041 mm, and 0.034 mm for control model, MB model, DB model, ML model, DL model, and AMB model, respectively. The first molars showed mesial tipping in the six models. The mesial movement of the mesiobuccal cusps of the first molars was 0.045 mm, 0.060 mm, 0.063 mm, 0.048 mm, 0.051 mm, and 0.055 mm for control model, MB model, DB model, ML model, DL model, and AMB model, respectively.

Conclusions

Class II elastics reduced lingual tipping of anterior teeth but aggravated mesial tipping of posterior teeth. Mesiolingual elastics developed minimum mesial tipping of the posterior teeth. When Class II elastics are required, attaching elastics on the mesiolingual surface of the mandibular first molar is recommended to prevent mandibular anchorage loss.

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.

Attractiveness of the facial profile: comparison of Class II patients treated with Twin Force® or intermaxillary elastics

Objective:

To compare the facial profile attractiveness of Class II patients treated with Twin Force^® or intermaxillary elastics.

Methods:

Sample comprised 47 Class II patients divided into two groups: G1) TWIN FORCE - 25 patients treated with fixed appliances and Twin Force^® fixed functional appliance (mean initial age was 17.91 ± 7.13 years, mean final age was 20.45 ± 7.18 years, and mean treatment time was 2.53 ± 0.83 years); G2) ELASTICS - 22 patients treated with fixed appliances and Class II intermaxillary elastics (mean initial age was 15.87 ± 5.64 years, mean final age was 18.63 ± 5.79 years and mean treatment time was 2.75 ± 0.60 years). Lateral cephalograms from pretreatment and posttreatment were used. Cephalometric variables were measured and silhouettes of facial profile were constructed and evaluated by 48 laypeople and 63 orthodontists, rating the attractiveness from 0 (most unattractive profile) to 10 (most attractive profile). Intergroup comparisons were performed with Mann-Whitney and independent t-tests.

Results:

At pretreatment, facial profile of the Twin Force^® group was less attractive than the Elastics group. Treatment with Twin Force^® or Class II elastics resulted in similar facial profile attractiveness, but the facial convexity was more reduced in the Twin Force^® group. Orthodontists were more critical than laypeople.

Conclusions:

Treatment with Twin Force^® or Class II elastics produced similar facial profile attractiveness at posttreatment. Profile attractiveness was reduced with treatment in the elastic group, and improved in the Twin Force^® group. Facial convexity was more reduced with treatment in the Twin Force^® group.

Differences in third molar development and angulation in class II subdivision malocclusions

PURPOSE

To assess and compare the developmental stages and angulations of third molars between the class II and class I sides in class II subdivision malocclusions.

METHODS

This retrospective study was performed using panoramic x‑rays of 38 individuals (mean age: 15.5 years; 24 females, 14 males) with class II subdivision malocclusions, which were further divided into type 1 and 2 subgroups according to midline deviation, and a control group of 42 individuals (mean age: 17.0 years; 30 females, 12 males) with normal occlusion. Third molars were categorized using the developmental stages defined by the Demirjian method. Angles between the third molars and horizontal reference lines and also to the second molars were measured.

RESULTS

No difference was found in developmental stages or angulations between the left and right third molars in the control group. In the class II subdivision malocclusion cases, no difference in third molar developmental stages was observed, but the angle between the long axes of the mandibular third and second molars was significantly greater on the class II side. In the type 2 subgroup, developmental stage of the maxillary third molar was more advanced on the class II side. In both subgroups, the angles of the maxillary third molars' long axis to the interorbital plane differed significantly between the two sides.

CONCLUSION

Class II subdivision malocclusion may cause differences in third molar development and angulations between the two sides. Orthodontic treatment should be planned considering the third molars in this malocclusion.

Stability of Class II Malocclusion Treatment with the Austro Repositioner Followed by Fixed Appliances in Brachyfacial Patients

One of the goals of functional-appliance devices is to modify the vertical growth pattern, solving several kinds of malocclusion. This study aimed to evaluate Class II malocclusion treatment’s stability with Austro Repositioner, followed by fixed appliances, and assess its capacity to modify vertical dimensions in brachyfacial patients. A test group of 30 patients (16 boys and 14 girls, mean 11.9 years old) with Class II malocclusion due to mandibular retrognathism and brachyfacial pattern treated with Austro Repositioner and fixed appliance were compared to a matched untreated Class II control group of 30 patients (17 boys and 13 girls, mean age 11.7 years old). Lateral cephalograms were taken at T1 (initial records), T2 (end of treatment), and T3 (one year after treatment). Statistical comparisons were performed with a paired-sample t-test and two-sample t-tests. Significant improvements in the skeletal Class II relationship were observed in the treated group. The ANB angle decreased (4.75°), the SNB angle increased (3.92°), and the total mandibular length (Co-Pg) increased (8.18 mm) (p < 0.001). Vertical dimensions were also significantly modified, the FMA angle increased (3.94°), LAFH-distance increased (3.15 mm), and overbite decreased (3.35 mm). These changes remained stable one year after treatment. The Austro Repositioner was adequate for treating the skeletal Class II malocclusion resulting from the mandible retrusion in brachyfacial patients.

The efficiency of mandibular mini-implants in reducing adverse effects of class II elastics in adolescent female patients: a single blinded, randomized controlled trial

BACKGROUND

Excessive proclination of lower incisors and other undesirable consequences usually result from the use of class II elastics during orthodontic treatment. The purpose of this study was to attempt to limit the adverse effects of class II elastics by the use of mini implants placed in the mandibular arch in adolescent class II female patients.

METHODS

The sample comprised 28 patients, (a mean age of 15.66 ± 2 years for intervention group and 15.1 ± 2.2 years for conventional group) with one-fourth or one-half unit class II canine relationship. The sample was divided into two equal groups. Randomization was carried out by a computer sequence generator with a 1:1 allocation ratio. In the intervention group, the mini implants were inserted between the lower second premolar and first molar, while the conventional group underwent regular class II elastics therapy. The active elastics treatment time was 8 months for both groups. Results were assessed by measurements from pre- and post-elastics lateral cephalometric radiographs.

RESULTS

The change in L1 inclination (0.97 ± 0.92°) and L1 AP position (0.31 ± 0.63 mm) did not show a statistically significant difference between the two groups, but a statistically significant difference was found in the U1 retroclination (5.23 ± 1.92°) and U1 distal movement (4.05 ± 1.4 mm) [P ˂ 0.001] and [P ˂ 0.05] respectively in favor of the intervention group.

CONCLUSION

Mini-implants in conjunction with class II elastics had no skeletal effect, mainly dentoalveolar and it did not prevent the proclination of lower incisors. There was more distal movement in the upper incisors in the skeletal anchorage group which helped in enhancing the camouflaging of class II malocclusion.

TRIAL REGISTRATION

Trial registered "FUE.REC (10)/10-2018" at the FUE registration council for clinical trials/IOP Orthodontic Program October 2018.

Treatment of mild Class II malocclusion in growing patients with clear aligners versus fixed multibracket therapy: A retrospective study

Objective

To compare the dental and skeletal effects of intermaxillary elastics on the correction of mild Angle's Class II division 1 malocclusion with clear aligner treatment (CA) versus fixed multibracket (FMB) in growing patients.

Settings and sample population

The study sample consisted of 49 consecutively patients (mean age ± SD 12.9 ± 1.7 years), 32 females and 17 males referred from the School of Orthodontics of the University of Bratislava Comenius (Slovakia). All patients were treated with a non‐extraction orthodontic treatment, 25 with FMB and 24 with CA.

Methods

The cephalometric analysis was performed at the beginning (T0) and the end of the treatment (T1). The t test for unpaired data was carried out to compare cephalometric values at T0 and changes at T1‐T0 between the two groups. The level of significance was set as P < .0035.

Results

The two groups showed no statistically significant differences (ANPg = −0.1°; P = .762) in the correction of the sagittal intermaxillary relation. The analysis of vertical skeletal changes showed no statistically significant effects on mandibular inclination (SN/MP = 0.1°; P = .840). The two treatments had a statistically significant and clinically relevant difference in controlling the inclination of the lower incisors (L1/GoGn = 4.8°, CAG = −0.5°± 3.9°; FMB = 4.3°± 5.8°; P < .001).

Conclusions

Class II elastics combined with CA and FMB produce a similar correction on sagittal discrepancies in growing patients. CA presented a better control in the proclination of the lower incisors. CA and elastics might be a good alternative in the correction of mild Class II malocclusion in cases where a proclination of lower incisors is unwanted.

Biomechanical analysis for total distalization of the maxillary dentition: A finite element study

INTRODUCTION

This study aimed to identify the tooth movement patterns relative to various force angulations (FAs) when distalizing the total maxillary dentition.

METHODS

Long-term orthodontic movement of the maxillary dentition was simulated by accumulating the initial displacement of teeth produced by elastic deflection of the periodontal ligament using a finite element analysis. Distalization forces of 3 N were applied to the archwire between the maxillary canine and first premolar at 5 different FAs (-30°, -15°, 0°, 15°, and 30°) to the occlusal plane.

RESULTS

Maxillary incisors and molars showed lingual and distal tipping at all FAs, respectively. At a force angulation of 30°, almost bodily distalization of the total maxillary dentition occurred, but incisors showed considerable lingual tipping because of the effect of clearance gap (0.003-in, 0.022 × 0.025-in bracket slot, 0.019 × 0.025-in archwire) and elastic deflection of the archwire. Medial displacement of the maxillary anterior teeth occurred because of lingual tipping during distalization. The occlusal plane rotated clockwise at all FAs because of extrusion of the maxillary incisors and intrusion of the maxillary second molars, and the amounts decreased as FA increased.

CONCLUSIONS

Tooth movement patterns during distalization of the total maxillary dentition were recognized. With an understanding of the mechanics, a proper treatment plan can be established.

Orthodontic treatment of an adolescent patient with Class II division 1 malocclusion with consideration of growth pattern and occlusal plane: A case report

Consideration of growth pattern and occlusal plane is critical in orthodontic treatment planning to achieve optimal dentofacial esthetics and long-term stability in adolescent patients, which is illustrated by success in orthodontic treatment of an adolescent Class II division 1 malocclusion with nonextraction.

Effects of fixed functional appliances with temporary anchorage devices on Class II malocclusion: A systematic review and meta‑analysis

BACKGROUND

The use of fixed functional appliances (FFAs) in conjunction with temporary anchorage devices (TADs) has been proposed to enhance skeletal changes and reduce proclination of the lower incisors.

OBJECTIVES

To systematically investigate the skeletal and dentoalveolar effects of FFAs with TADs on Class II malocclusion in adolescents.

METHODS

Electronic searches of databases and manual searches of references were performed up to August 30, 2020. Randomized controlled trials (RCTs) and clinical controlled trials (CCTs) focusing on adolescent patients treated with FFAs combining TADs were included. The modified Cochrane risk-of-bias tool (R.O.B 2.0) and ROBINS-I (Risk of Bias in Non-randomized Studies-of Interventions) Tool were used to assess the risk of bias in RCTs and CCTs, respectively. Meta-analyses of SNA, SNB, ANB, Co-Gn, SN-MP, the lower and upper incisor inclination changes were performed. Subgroup analyses and sensitivity analyses were conducted based on TAD types, FFA types, record types and types of study designs.

RESULTS

Ten studies were included with a sample size of 281. Meta-analyses revealed significant differences in the changes in SNB (mean difference [MD] 0.67; 95% confidence interval [CI] 0.04-1.29), ANB (MD -1.22, 95% CI -2.04 to -0.39), Co-Gn (MD 1.57; 95% CI 0.22-2.92), inclination of the lower incisors (MD -5.64, 95% CI -7.78 to -3.50)] and inclination of the upper incisors (MD -1.91; 95% CI -3.69 to -0.13). TAD types and FFA types seem to affect the treatment outcome.

CONCLUSIONS

Compared with FFAs alone, FFAs with TADs exhibit superior skeletal effects and reduce the inclination of the lower incisors in the short term; however, the evidence showed moderate to high risk of bias. Registration number CRD42020177611.

Soft tissue profile changes in Angle class II patients treated with Twin Force or intermaxillary elastics-a comparison

PROPOSITION

This study aimed to compare soft tissue profile changes in Angle class II malocclusion patients treated with a Twin Force appliance (Ortho Organizers, Inc., Carlsbad, CA, USA) or class II elastics.

METHODS

The sample comprised 47 class II malocclusion patients treated orthodontically without extractions, divided into two groups. Group 1 (Twin Force): 25 patients were treated with the Twin Force, with initial and final mean ages of 17.91 and 20.45 years, respectively, and mean treatment time of 2.53 years. Group 2 (elastics): 22 patients were treated with class II elastics, with initial and final mean age of 15.87 and 18.63 years, respectively, and mean treatment time of 2.75 years. The lateral cephalograms were evaluated at the initial and final stages. Intragroup comparisons were performed with dependent t-tests and intergroup comparisons were performed with independent t-tests.

RESULTS

Treatment-related changes in the Twin Force group included reduction of facial convexity, retrusion of the upper lip, increase of the H‑Nose distance, and decrease in Sn‑H distance, indicating improvement in facial profile. In the elastics group, treatment resulted in an increase in nasolabial angle, retrusion of the upper lip, increase of the H‑Nose distance, and decrease in Sn‑H distance, indicating improvement in facial profile. The Twin Force group showed a greater reduction of the facial convexity with treatment than the elastics group.

CONCLUSIONS

Class II patients treated with the Twin Force appliance showed greater reduction in facial convexity than patients treated with class II elastics. The other soft tissue changes were similar for both groups.

Treatment outcome and long-term stability of class II correction with forsus fatigue resistant device in non-growing patients

OBJECTIVES

Forsus™ Fatigue Resistant Device (FRD) is one of the commonly used semirigid fixed functional devices. Purpose of the present study was to investigate effects and long-term stability of Class II correction following use of Forsus FRD in a retrospective clinical study.

SETTING AND SAMPLE POPULATION

Records of 20 patients (mean age 18.3 ± 2.5 years) with Class II malocclusion, who had undergone fixed functional treatment protocol with Forsus FRD, were collected from our clinical archive.

MATERIALS AND METHODS

Lateral cephalometric radiographs at pre-treatment (T0), end of comprehensive treatment (T1) and post-retention period (T2, mean duration: 19 ± 3 months) were analysed and superimposed to assess skeletal and dental changes on the long-term. Repeated measurement one way ANOVA was used for the study of the significant differences among the mean values of cephalometric parameters at T0, T1, and T2. To analyse the nature of the bilateral significant differences between two different time points, Bonferroni test was used.

RESULTS

Sagittal and vertical skeletal changes at T0-T1 were statistically insignificant while all dentoalveolar parameters exhibited highly significant changes. At T1-T2, all skeletal and dentoalveolar parameters were stable except the slight relapse in overjet (0.3 ± 0.5 mm; P < .05). At T0-T2 interval, no significant skeletal changes were recorded while the dentoalveolar changes remained significantly improved.

CONCLUSION

Correction of Class II malocclusion achieved with Forsus FRD was dentoalveolar and treatment effects were stable in the 19 ± 3 months follow-up period.

Dentoskeletal and soft-tissue changes comparison between the Jasper Jumper and Twin Force Bite Corrector in Class II malocclusion patients: A retrospective study

OBJECTIVE

This retrospective study aimed to compare the dentoskeletal and soft-tissue changes in Class II malocclusion patients treated with Jasper Jumper and Twin Force Bite Corrector associated with fixed orthodontic appliances.

MATERIAL AND METHODS

The sample comprised 60 subjects divided into 3 groups. Patients with Class II malocclusion, mandibular retrusion, slight or no crowding and with no previous orthodontic treatment were eligible. Group 1 comprised 20 patients treated with the Jasper Jumper (JJ), with an initial age of 12.39 years. Group 2 comprised 20 patients treated with the Twin Force (TF), with an initial age of 11.83 years. The control group consisted of 20 untreated Class II subjects with an initial age of 12.13 years. Intergroup pretreatment comparisons were performed with One-way analysis of variance and intergroup treatment changes were compared with the Analysis of Covariance, both followed by Tukey test.

RESULTS

The TF group showed greater increase in mandibular length (6.23mm±4.64, P=0.004) than the control group (2.94mm±1.75). The mandibular incisors in the experimental groups presented significantly greater labial inclination and protrusion than the control (Md1.NB; JJ: 4.19°±2.09; TF: 4.46°±6.83; control: 1.13°±2.08, P=0.000/Md1-NB; JJ: 1.95mm±1.45; TF: 1.74mm±1.79; control: 0.31mm±0.81, P=0.000). In addition, the treated groups also showed significantly improvement of the dental relationships (Overjet; JJ: -4.05mm±4.64; TF: -3.80mm±2.12; control: 0.05mm±1.12, P=0.000/Overbite; JJ: -2.52mm±1.46; TF: -2.93mm±2.13; control: -0.63mm±1.35, P=0.000).

CONCLUSION

The Jasper Jumper and Twin Force associated to fixed appliances were effective in correcting Class II malocclusion with a combination of skeletal and dentoalveolar changes. However, the TF seems to provide more skeletal effects with greater maxillary growth restriction and mandibular length increase when compared to the JJ.

Orthodontic treatment time: can it be shortened?

INTRODUCTION

In the literature, no consensus has been reached about orthodontic treatment time. Similarly, the determining factors of the latter have not yet been completely elucidated.

OBJECTIVE

The aim of the present article was to deepen the discussion on the major factors influencing orthodontic treatment time, as well as to present some strategies that have proven effective in controlling and shortening it.

METHOD

Based on evidences found in the literature, the method focussed in providing the basis for clinical decision-making.

CONCLUSIONS

Treatment time varies according to the type of malocclusion and treatment options. Orthodontist's influence, patient's characteristics and compliance are all decisive in determining treatment time, while the effects provided by orthodontic appliances and methods used to speed tooth movement up seem little effective.

Asymmetric dental arch treatment with Forsus fatigue appliances: Long-term results

OBJECTIVES

To investigate the treatment efficacy and follow-up stability of the asymmetric Forsus appliance by evaluating longitudinal changes in dental arch asymmetry on digital dental models from 21 patients.

MATERIALS AND METHODS

Maxillary and mandibular reference lines were used for measurements of intra-arch asymmetry at pretreatment (T1), posttreatment (T2), and 4.2 years after treatment (T3). Maxillary and mandibular measurements were performed relative to the dental midline and anterior reference line on digital dental models. To determine the amount of asymmetry between the Class I and Class II sides of a given arch, all maxillary and mandibular parameters were measured on each side of the model separately. Repeated-measures analysis of variance/paired sample t-tests were performed to evaluate dental arch asymmetries at the P < .05 level.

RESULTS

The alveolar transverse dimensions of the posterior segment of both arches were increased during treatment (P < .05) and remained stable during the retention period. Class II subdivision malocclusion was caused by distal positioning of the mandibular canine, premolars, and first molar on the Class II side (P < .05). Asymmetry was resolved by treatment with asymmetric Forsus appliances. The resolved asymmetry remained stable over the long term. There were no significant differences between T2 and T3 (P > .05).

CONCLUSIONS

The asymmetric Forsus appliance can be used to treat dental arch asymmetry in patients with Class II subdivision malocclusions.

Class II Division 2 Subdivision Malocclusion in an Adult Patient treated with the Forsus Fatigue-resistant Device placed Unilaterally

Treatment of Class II subdivision malocclusion is challenging, and orthodontists frequently struggle to determine the choice of treatment. Several treatment modalities have been proposed for correcting these types of malocclusion. Thus, the aim of this case report is to present dentoalveolar and facial outcomes achieved using an unilateral Forsus fatigue-resistant device combined with fixed appliances in an adult female patient presenting with Class II subdivision malocclusion. Treatment outcome was effective producing dental esthetics and functional positive stable results after 3-year, 2-month follow-up.

Twenty-year clinical experience with fixed functional appliances

Introduction:

Considering the large number of fixed functional appliances, choosing the best device for your patient is not an easy task.

Objective:

To describe the development of fixed functional appliances as well as our 20-year experience working with them.

Methods:

Fixed functional appliances are grouped into flexible, rigid and hybrid. They are different appliances, whose action is described here. Four clinical cases will be reported with a view to illustrating the different appliances.

Conclusions:

Rigid fixed functional appliances provide better skeletal results than flexible and hybrid ones. Flexible and hybrid appliances have similar effects to those produced by Class II elastics. They ultimately correct Class II with dentoalveolar changes. From a biomechanical standpoint, fixed functional appliances are more recommended to treat Class II in dolichofacial patients, in comparison to Class II elastics.

Orthodontic treatment for prominent upper front teeth (Class II malocclusion) in children and adolescents

BACKGROUND

Prominent upper front teeth are a common problem affecting about a quarter of 12-year-old children in the UK. The condition develops when permanent teeth erupt. These teeth are more likely to be injured and their appearance can cause significant distress. Children are often referred to an orthodontist for treatment with dental braces to reduce the prominence of their teeth. If a child is referred at a young age, the orthodontist is faced with the dilemma of whether to treat the patient early or to wait and provide treatment in adolescence.

OBJECTIVES

To assess the effects of orthodontic treatment for prominent upper front teeth initiated when children are seven to 11 years old ('early treatment' in two phases) compared to in adolescence at around 12 to 16 years old ('late treatment' in one phase); to assess the effects of late treatment compared to no treatment; and to assess the effects of different types of orthodontic braces.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 27 September 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 8), MEDLINE Ovid (1946 to 27 September 2017), and Embase Ovid (1980 to 27 September 2017). The US National Institutes of Health Ongoing Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials of orthodontic treatments to correct prominent upper front teeth (Class II malocclusion) in children and adolescents. We included trials that compared early treatment in children (two-phase) with any type of orthodontic braces (removable, fixed, functional) or head-braces versus late treatment in adolescents (one-phase) with any type of orthodontic braces or head-braces, and trials that compared any type of orthodontic braces or head-braces versus no treatment or another type of orthodontic brace or appliance (where treatment started at a similar age in the intervention groups).We excluded trials involving participants with a cleft lip or palate, or other craniofacial deformity/syndrome, and trials that recruited patients who had previously received surgical treatment for their Class II malocclusion.

DATA COLLECTION AND ANALYSIS

Review authors screened the search results, extracted data and assessed risk of bias independently. We used odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) and 95% CIs for continuous outcomes. We used the fixed-effect model for meta-analyses including two or three studies and the random-effects model for more than three studies.

MAIN RESULTS

We included 27 RCTs based on data from 1251 participants.Three trials compared early treatment with a functional appliance versus late treatment for overjet, ANB and incisal trauma. After phase one of early treatment (i.e. before the other group had received any intervention), there was a reduction in overjet and ANB reduction favouring treatment with a functional appliance; however, when both groups had completed treatment, there was no difference between groups in final overjet (MD 0.21, 95% CI -0.10 to 0.51, P = 0.18; 343 participants) (low-quality evidence) or ANB (MD -0.02, 95% CI -0.47 to 0.43; 347 participants) (moderate-quality evidence). Early treatment with functional appliances reduced the incidence of incisal trauma compared to late treatment (OR 0.56, 95% CI 0.33 to 0.95; 332 participants) (moderate-quality evidence). The difference in the incidence of incisal trauma was clinically important with 30% (51/171) of participants reporting new trauma in the late treatment group compared to only 19% (31/161) of participants who had received early treatment.Two trials compared early treatment using headgear versus late treatment. After phase one of early treatment, headgear had reduced overjet and ANB; however, when both groups had completed treatment, there was no evidence of a difference between groups in overjet (MD -0.22, 95% CI -0.56 to 0.12; 238 participants) (low-quality evidence) or ANB (MD -0.27, 95% CI -0.80 to 0.26; 231 participants) (low-quality evidence). Early (two-phase) treatment with headgear reduced the incidence of incisal trauma (OR 0.45, 95% CI 0.25 to 0.80; 237 participants) (low-quality evidence), with almost half the incidence of new incisal trauma (24/117) compared to the late treatment group (44/120).Seven trials compared late treatment with functional appliances versus no treatment. There was a reduction in final overjet with both fixed functional appliances (MD -5.46 mm, 95% CI -6.63 to -4.28; 2 trials, 61 participants) and removable functional appliances (MD -4.62, 95% CI -5.33 to -3.92; 3 trials, 122 participants) (low-quality evidence). There was no evidence of a difference in final ANB between fixed functional appliances and no treatment (MD -0.53°, 95% CI -1.27 to -0.22; 3 trials, 89 participants) (low-quality evidence), but removable functional appliances seemed to reduce ANB compared to no treatment (MD -2.37°, 95% CI -3.01 to -1.74; 2 trials, 99 participants) (low-quality evidence).Six trials compared orthodontic treatment for adolescents with Twin Block versus other appliances and found no difference in overjet (0.08 mm, 95% CI -0.60 to 0.76; 4 trials, 259 participants) (low-quality evidence). The reduction in ANB favoured treatment with a Twin Block (-0.56°, 95% CI -0.96 to -0.16; 6 trials, 320 participants) (low-quality evidence).Three trials compared orthodontic treatment for adolescents with removable functional appliances versus fixed functional appliances and found a reduction in overjet in favour of fixed appliances (0.74, 95% CI 0.15 to 1.33; two trials, 154 participants) (low-quality evidence), and a reduction in ANB in favour of removable appliances (-1.04°, 95% CI -1.60 to -0.49; 3 trials, 185 participants) (low-quality evidence).

AUTHORS' CONCLUSIONS

Evidence of low to moderate quality suggests that providing early orthodontic treatment for children with prominent upper front teeth is more effective for reducing the incidence of incisal trauma than providing one course of orthodontic treatment in adolescence. There appear to be no other advantages of providing early treatment when compared to late treatment. Low-quality evidence suggests that, compared to no treatment, late treatment in adolescence with functional appliances, is effective for reducing the prominence of upper front teeth.

Three-dimensional positional assessment of glenoid fossae and mandibular condyles in patients with Class II subdivision malocclusion

OBJECTIVES

To test the null hypotheses that the positions of the glenoid fossae and mandibular condyles are identical on the Class I and Class II sides of patients with Class II subdivision malocclusion.

MATERIALS AND METHODS

Retrospective three-dimensional (3D) assessments of the positions of the glenoid fossae and mandibular condyles were made in patients with Class II malocclusion. Relative to a fiducial reference at the anterior cranial base, distances from the glenoid fossae and condyles were calculated in pretreatment cone beam computed tomographic scans of 82 patients: 41 with Class II and 41 with Class II subdivision malocclusions. The 3D distances from glenoid fossae to sella turcica in the X (right-left), Y (anterior-posterior), Z (inferior-superior) projections were calculated.

RESULTS

Patients with Class II malocclusion displayed a symmetric position of the glenoid fossae and condyles with no statistically significant differences between sides (P > .05), whereas patients with Class II subdivision showed asymmetry in the distance between the glenoid fossae and anterior cranial base or sella turcica (P < .05), with distally and laterally positioned glenoid fossae on the Class II side. (P < .05). Male patients had greater distances between glenoid fossae and anterior cranial fossae (P < .05). The condylar position relative to the glenoid fossae did not differ between the two malocclusion groups nor between males and females (P > .05).

CONCLUSIONS

The null hypotheses were rejected. Patients with Class II subdivision malocclusion displayed asymmetrically positioned right- and left-side glenoid fossae, with a distally and laterally positioned Class II side, although the condyles were symmetrically positioned within the glenoid fossae.