Stability of Class II treatment with an edgewise crowned Herbst appliance in the early mixed dentition: Skeletal and dental changes

Oral Implications of Herbst Device Modification: A Case Report

BACKGROUND

Many studies analyse the effectiveness of the Herbst device in the treatment of dentoskeletal Class II malocclusion due to mandibular retrusion. This fixed device was devised by Emil Herbst for Class II treatment using a bite jumping, i.e., a device that holds the jaw in a forced anterior position. Comparison of the results obtained in numerous studies is difficult because they are often not comparable and not congruent due to a number of variables that prevent standardization.

METHODS

The purpose of the present study is to report some clinical-level considerations that may be important in order to obtain more predictable therapeutic outcomes. The simplified design of the Herbst device offers better patient comfort and easier cleanability but may show some disadvantages, such as less anchorage.

RESULTS

The device was evaluated in conjunction with the multi-bracket phase that preceded Herbst therapy and concluded after the device was removed. The therapy was performed in the absence of skeletal anchorage.

CONCLUSIONS

In our opinion, standardization of therapy according to precise protocols may positively affect the therapeutic outcomes by achieving faster occlusal stabilization, more proper neuro-muscular balance, less stress on anchor units, and shorter treatment time.

Comparisons of soft tissue changes after Herbst appliance treatment in three different growth phases

BACKGROUND

This study aimed to compare the soft tissue effects of Herbst appliance in Class II malocclusion patients treated in three different craniofacial growth phases: prepubertal (PRE), circumpubertal (CIR), and postpubertal (POS).

METHODS

In total, 95 patients with Class II Division 1 malocclusion previously treated with a Herbst appliance were analyzed. Through the cervical vertebral maturation stages method, patients were allocated into three groups depending on the growth craniofacial phase at the beginning of treatment: PRE, CIR, and POS. Seventeen cephalometric measures were evaluated from each lateral radiograph before and after Herbst therapy using the Radiocef 2 software (Radio Memory, Belo Horizonte). Intragroup and intergroup treatment changes were compared statistically using a paired t test and MANOVA test, respectively.

RESULTS

Soft tissue thickness changes were related only to mandible; all three mandibular measurements (L1_LL, B_B', and Pog_Pog') showed thickening for the PRE group ranging from 0.92 mm (Pog_Pog') to 2.02 mm (B_B'), and only lower lip thickened overtime for the POS group (L1_LL = 0.99 mm). Soft and hard tissue pogonion displaced anteriorly, but only the soft tissue showed differences among groups; PRE group presented more anterior displacement than POS group (3.61 mm and 1.39 mm, respectively). Hard and soft tissue facial convexity decreased more in the PRE and CIR groups than in the POS group. Mentolabial sulcus depth reduced more in the PRE (1.07 mm) and CIR (1.29 mm) groups than in the POS (0.55 mm) group. Horizontal movement of the skeletal and soft pogonion presented a moderate-high positive correlation (r = 0.783), and hard and soft facial convexity showed a moderate-low positive correlation (r = 0.403).

CONCLUSIONS

Herbst appliance therapy produces soft tissue improvements in the three phases of craniofacial growth, being greater in patients in the PRE and CIR phases.

Assessment of the condylar response of two differently anchored fixed functional appliances in class II malocclusion in young adult orthodontic patients: A randomized clinical trial

OBJECTIVE

Measuring the condylar volume changes after treatment with skeletally anchored type IV Herbst appliance vs. Twin Force Bite Corrector (TFBC) in class II malocclusion in young adult patients.

MATERIALS AND METHODS

Twenty class II malocclusion participants were randomly involved in our randomized clinical study. They are divided equally into two groups: group I (10 patients with an age range of 16 to 18 years and a mean age of (17.15 ± 0.62) (five males and five females) with a mean Angle formed between (A) point and (Nasion) point and (B) point, to determine anteroposterior relation between maxilla and mandible (ANB) of 6.20 (1.03) and a mean mandibular length of 106.1 (1.7), who were treated by a skeletally anchored type IV Herbst appliance, supported at the mandible by two mini-plates fixed bilaterally at the mandibular symphysis; group II (10 patients with an age range of 15 to 18 years and a mean age of (16.85 ± 0.33) (six males and four females) with a mean ANB of 6.80 (0.89) and a mean mandibular length of 107.3 (2.36), who were treated by a TFBC that was installed just mesial to the tube of the maxillary first permanent molar and distal to the bracket of the lower canine for 4 months. According to the Index of Orthognathic Functional Treatment Need (IOFTN) index, the participants in both groups have grade 4 (great need for treatment) as they have excessive overjet (6-9 mm). Cone-beam computed tomography (CBCT) was taken just before installing fixed functional appliances and after the removal. The condylar volume was measured using Dolphin software. Parametric measurements were performed by the independent t-test, while non-parametric variables (percent change) were compared by the Mann-Whitney U-test.

RESULTS

On the right side, the Herbst group recorded a percent increase (median = 1.23%), while TFBC recorded a median percent decrease (-7.85%). This change is statistically significant (P = 0.008).

CONCLUSIONS

The difference in the condylar volume was significantly higher with the mini-plate anchored Herbst appliance than with the dentally anchored TFBC group.

A comparison of skeletal and dental changes in patients with a Class II relationship treated with clear aligner mandibular advancement and Herbst appliance followed by comprehensive orthodontic treatment

INTRODUCTION

The objective of this study was to compare the skeletal and dental changes of patients with a Class II relationship treated with clear aligner mandibular advancement (MA) and Herbst appliances followed by comprehensive orthodontic treatment.

METHODS

The participants included 20 patients treated with MA and 20 with the Herbst appliance. Orthodontic records were taken before treatment, after the functional appliance, and completion of phase II treatment. The skeletal and dental changes across the 3-time periods were evaluated using a matched paired t test for each treatment. A 2-sample t test was used to examine the changes across periods between 2 treatment groups (P <0.05).

RESULTS

Significant reduction in overjet, overbite, and change in molar relationship were obtained by both appliances with similar skeletal and dental contributions. This was contributed by a forward movement of the mandible and mandibular molars, backward movement of the maxillary molars, and retraction of the maxillary incisors. After phase II treatment, both appliances could maintain the skeletal and dental changes achieved during the advancement phase. Greater change in overbite (2.4 mm vs 1.4 mm), an eruption of maxillary incisors (0.9 mm vs 0.1 mm), and proclination of mandibular incisors were found with the Herbst group (3.9° vs -2.1°). The average total treatment time was similar with the 2 appliances.

CONCLUSIONS

Both functional appliances were equally effective in reducing the overjet and overbite and achieving a Class I molar relationship with a similar length of treatment time. The Herbst design lacked control of the mandibular incisor proclination, and clear aligners offered better vertical control and management of the mandibular incisor inclination.

Long-term stability of Class II malocclusion treatment with the cantilever bite jumper

INTRODUCTION

This study aimed to assess the long-term stability of Class II malocclusion treatment with the Cantilever Bite Jumper (CBJ) after 13 years of follow-up.

METHODS

The treatment group comprised 10 Class II Division 1 malocclusion patients treated with the CBJ, followed by fixed appliances, analyzed at 3 stages: pretreatment (aged 11.56-14.32 years), posttreatment (aged 16.34-19.58 years), and long-term posttreatment (aged 29.04-32.33 years). The control group included 15 subjects with normal occlusion. Intragroup treatment changes comparison was performed with repeated measures and analysis of variance followed by Tukey tests. Intergroup comparisons regarding the long-term posttreatment changes were performed with t tests.

RESULTS

No statistically significant relapse was observed during the follow-up period. Morever, the treated group presented a significantly smaller increase in lower anterior facial height and greater retrusion of the lower lip than the control group in the posttreatment period.

CONCLUSIONS

Treatment with the CBJ, followed by fixed appliances, is a stable alternative for Class II Division 1 malocclusion correction. The dentoskeletal and soft-tissue changes obtained during treatment remained stable in the long-term posttreatment follow-up.

Comparative Analysis of Dentoskeletal Changes of the Twin Block Appliance and the AdvanSync2 Appliance in Treatment of Skeletal Class-II Malocclusion in Pakistani Population: A Randomized Clinical Trial

Objective  This study aimed to compare dentoskeletal changes in skeletal class-II malocclusion with removable twin block appliance and fixed AdvanSync2 appliance.

Materials and Methods  A prospective randomized clinical trial was conducted over a span of 1 year at AFID at Rawalpindi. Thirty patients with skeletal class-II malocclusion, 16 males (53.3%) and 14 females (46.6%), were randomly selected and divided in two equal groups (15 each) to be treated with either fixed functional appliances (FFAs) or with removable functional appliances (RFAs). Out of 30 patients, 15 between cervical vertebral maturation (CVM) stages of 2 and 3 were treated with RFA (twin block appliances) and remaining 15 between CVM stages of 4 and 5 were treated with FFA (AdvanSync2 appliances). Pretreatment (T ₁ ) and posttreatment (T ₂ ), angular variable, and linear variable were measured to compare the dentoskeletal effects between the two groups.

Statitical Analysis  Paired sample t-test was used to assess significant difference between variables at T1 (Pre-treatment) and T2 (Post-treatment) stage for both RFA and FFA group. Comparison among the RFA and FFA group was made using non-parametric Mann-Whitney U Test. IBM SPSS version 25.0 was used for evaluation.

Results  No significant difference was found in angular variables between the RFA and FFA groups ( p  > 0.05) with the exception of linear variables. Sella-posterior nasal spine (S-PNS) length significantly increased and Jarabak's ratio significantly decreased for FFA group ( p  = 0.010 and 0.045, respectively), when compared with RFA group.

Conclusion  Both the appliances, twin block (RFA) and AdvanSync2 (FFA), are effective for correction of skeletal class-II malocclusion. Both the appliances produced similar effects in the sagittal plane but for better vertical control twin block should be the appliance of choice. AdvanSync2 appliance could be preferred over twin block appliance when dentoalveolar and slight retrusive effect on the maxilla is desired especially for individuals in postpubertal growth spurt.

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).

Comparison of treatment outcomes with crowned and banded mandibular anterior repositioning appliance (MARA) in Class II pubertal subjects: A retrospective cohort study

OBJECTIVE

To compare the skeletal and dentoalveolar changes in Angle Class II malocclusion subjects treated with the banded Mandibular Anterior Repositioning Appliance (Ba-MARA) and crowned MARA (Cr-MARA).

MATERIALS AND METHODS

This retrospective cohort study included 40 consecutively treated pubertal adolescents with Class II division 1 malocclusion who received full-fixed orthodontic appliances with a phase of orthopedic treatment using Ba-MARA (n=20) or Cr-MARA (n=20). The samples were compared with 20 untreated Class II controls obtained from the Michigan Growth Study. Lateral cephalograms were obtained pre-treatment (T1), post-MARA removal (T2), and post-full-fixed orthodontic treatment (T3).

RESULTS

After MARA removal (T2-T1), the total mandibular length increased only in the Cr-MARA group compared to controls (Co-Gn=5.4mm; post-hoc P=0.042). Overall dentoskeletal changes were less significant during the T3-T2 timepoint. After full-fixed orthodontic treatment (T3-T1), and after controlling for normal growth, both Ba- and Cr-MARA groups increased the total mandibular length by 3.1mm and 3.8mm respectively. Overjet decreased by 2.2mm in Ba-MARA and 2.9mm in Cr-MARA. The mandibular molars erupted and moved mesially in both treatment groups. The mandibular incisors proclined significantly in the Cr-MARA group in comparison to controls (IMPA=7.1^o, post-hoc P=0.002).

CONCLUSIONS

Both MARA designs were effective in correcting the malocclusion by a combination of small skeletal and dental changes. Although significant differences in dentoskeletal outcomes were observed between the MARA groups and the controls, the differences between the two MARA designs were small and did not achieve statistical/clinical significance.

Effects of Class II division 1 malocclusion treatment with three types of fixed functional appliances

Objective:

This study aimed at comparing the dentoskeletal changes in patients with Class II division 1 malocclusion, treated with three types of fixed functional appliances.

Methods:

A sample comprising 95 patients with the same malocclusion, retrospectively selected, and divided into four groups, was used: G1 consisted of 25 patients (mean age 12.77 ± 1.24 years) treated with Jasper Jumper appliance; G2, with 25 patients (mean age 12.58 ± 1.65 years) treated with the Herbst appliance; G3, with 23 patients (mean age 12.37 ± 1.72 years) treated with the Mandibular Protraction Appliance (MPA); and a Control Group (CG) comprised of 22 untreated subjects (mean age 12.66 ± 1.12 years). Intergroup comparison was performed with ANOVA, followed by Tukey test.

Results:

The Jasper Jumper and the Herbst group showed significantly greater maxillary anterior displacement restriction. The Jasper Jumper demonstrated significantly greater increase in the mandibular plane angle, as compared to the control group. The MPA group demonstrated significantly greater palatal inclination of the maxillary incisors. Vertical development of the maxillary molars was significantly greater in the Herbst group.

Conclusions:

Despite some intergroup differences in the amount of dentoskeletal changes, the appliances were effective in correcting the main features of Class II malocclusions.

Three-dimensional comparison of the skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed appliances: A CBCT study

OBJECTIVES

To compare three-dimensional (3D) skeletal and dentoalveolar effects of the Herbst and Pendulum appliances followed by fixed orthodontic treatment in growing patients.

SETTING AND SAMPLE POPULATION

A sample of 35 adolescents with cone-beam computed tomography scans obtained prior to Herbst and Pendulum treatment (T1) and immediately after fixed appliance treatment (T2).

MATERIALS AND METHODS

Patients with Class II malocclusion was assessed retrospectively and divided into two treatment groups: Herbst group (n = 17, age: 12.0 ± 1.6 years) and Pendulum group (n = 18, age: 12.1 ± 1.5 years), with a mean treatment duration of 2.8 ± 0.8 years and 2.5 ± 0.7 years, respectively. Reconstructions of the maxillomandibular and dentoalveolar regions and data in 3D were obtained relative to cranial base, maxillary and mandibular regional superimpositions. Treatment outcomes (T2-T1) were compared between both groups using t tests for independent samples (P<.05).

RESULTS

Significant increase in mandibular length was observed in the Herbst group (7.3 ± 3.5 mm) relative to the Pendulum group (4.6 ± 4.5 mm). Inferior and anterior displacements of Pogonion were 2.2 mm and 1.6 mm greater in the Herbst group, respectively. The mesial displacement of the lower first molars was significantly greater in the Herbst group (1.9 mm). The upper first molars had contrasting results in sagittal displacement, with 0.6 ± 1.7 mm of distal displacement with the Pendulum and 1.4 ± 2.1 mm of mesial displacement with the Herbst. Lower incisor projection and proclination were similar between groups.

CONCLUSIONS

The Herbst and Pendulum appliances followed by comprehensive orthodontic treatment effectively corrected Class II malocclusion in growing patients, but with differing skeletal and dentoalveolar effects.

Long-term effects of functional appliances in treated versus untreated patients with Class II malocclusion: A systematic review and meta-analysis

Objective

To assess the cephalometric skeletal and soft-tissue of functional appliances in treated versus untreated Class II subjects in the long-term (primarily at the end of growth, secondarily at least 3 years after retention).

Search methods

Unrestricted electronic search of 24 databases and additional manual searches up to March 2018.

Selection criteria

Randomised and non-randomised controlled trials reporting on cephalometric skeletal and soft-tissue measurements of Class II patients (aged 16 years or under) treated with functional appliances, worn alone or in combination with multi-bracket therapy, compared to untreated Class II subjects.

Data collection and analysis

Mean differences (MDs) and 95% confidence intervals (95% CIs) were calculated with the random-effects model. Data were analysed at 2 primary time points (above 18 years of age, at the end of growth according to the Cervical Vertebral Maturation method) and a secondary time point (at least 3 years after retention). The risk of bias and quality of evidence were assessed according to the ROBINS tool and GRADE system, respectively.

Results

Eight non-randomised studies published in 12 papers were included. Functional appliances produced a significant improvement of the maxillo-mandibular relationship, at almost all time points (Wits appraisal at the end of growth, MD -3.52 mm, 95% CI -5.11 to -1.93, P < 0.0001). The greatest increase in mandibular length was recorded in patients aged 18 years and above (Co-Gn, MD 3.20 mm, 95% CI 1.32 to 5.08, P = 0.0009), although the improvement of the mandibular projection was negligible or not significant. The quality of evidence was ‘very low’ for most of the outcomes at both primary time points.

Conclusions

Functional appliances may be effective in correcting skeletal Class II malocclusion in the long-term, however the quality of the evidence was very low and the clinical significance was limited.

Systematic review registration

CRD42018092139

Skeletal Class II Case Presentation: Utilization of the AdvanSync 2 Appliance

The Herbst appliance has been used routinely in the specialty of orthodontics for nearly 40 years. Over this time, many design variations have been utilized. One of the recent designs is the AdvanSync 2 appliance, manufactured by Ormco. The AdvanSync 2 appliance is smaller than the conventional Herbst appliances and allows the clinician to place braces on all the permanent teeth forward of the first molars. In the case presented, the patient presented with a skeletal Class II, division 2 malocclusion. Facially, it was determined that mandibular advancement would be advantageous for ideal facial esthetics. The result of treatment utilizing the Damon System braces and the AdvanSync 2 Class II corrector was an excellent outcome both dentally and in regard to facial esthetics.

Three-dimensional treatment outcomes in Class II patients with different vertical facial patterns treated with the Herbst appliance

INTRODUCTION

The aims of this study were to evaluate, using 3-dimensional superimposition techniques, the skeletal changes in Class II subjects with different vertical facial patterns treated with the Herbst appliance and to compare these skeletal changes to those of Class II controls treated with elastics.

METHODS

Sixteen Herbst patients who met the inclusion criteria were divided into 2 equal groups based on vertical facial pattern as determined by the Frankfort mandibular plane angle (brachyfacial, ≤22°; mesofacial, 23°-29°) and had cone-beam computed tomographs taken before treatment, 8 weeks after Herbst appliance removal, and after subsequent fixed appliance treatment. Eleven Class II control patients treated with fixed appliances and elastics had cone-beam computed tomographs taken before and after treatment. Three-dimensional models were generated from the cone-beam computed tomography images, registered on the anterior cranial bases, and analyzed using color maps and point-to-point measurements.

RESULTS

There were minimal differences in treatment response between the 2 Herbst groups across all skeletal parameters measured. The Herbst subjects showed a greater inferior displacement of anterior nasal spine compared with the Class II controls (Herbst brachyfacial, -1.44 mm; Herbst mesofacial, -1.95 mm) with other maxillary changes being clinically insignificant. The Herbst subjects showed greater inferior displacement of B-point compared with the Class II controls (Herbst brachyfacial, -2.59 mm; Herbst mesofacial, -2.75 mm). There were no statistically significant differences in mean linear mandibular measurements. All groups showed a trend toward posterior displacement of the condyles and glenoid fossae from the start to the end of treatment, with no significant differences across the 3 groups. There were minimal differences in the changes in gonial angle and Frankfort mandibular plane angle across all groups.

CONCLUSION

Approximately 2 years after Herbst treatment, the Herbst subjects with different vertical facial patterns showed similar patterns of skeletal change compared with the Class II controls treated with elastics.

Long-term stability of Class II treatment with the Jasper jumper appliance

INTRODUCTION

Treatment of Class II Division 1 malocclusion with orthopedic devices combined with fixed orthodontic appliances has shown excellent results when used in growing patients. We aimed to evaluate the long-term stability of the cephalometric changes obtained during Class II malocclusion correction with the Jasper jumper associated with fixed appliances.

METHODS

The treatment group comprised 24 patients who were evaluated at 3 stages: pretreatment, posttreatment, and long-term posttreatment. The control group comprised 15 subjects with normal occlusion. Intratreatment group comparisons among the 3 stages were performed with repeated measures analysis of variance, followed by Tukey tests. Intergroup comparisons of posttreatment changes and normal growth changes of the treatment group were performed with t tests.

RESULTS

Apical base relationship, maxillary incisor anteroposterior position, and overjet demonstrated significant relapses in relation to the control group.

CONCLUSIONS

Most dentoalveolar changes obtained with the Jasper jumper followed by fixed appliances during treatment remained stable in the long term. However, apical base relationship, maxillary incisor anteroposterior position, and overjet demonstrated significant relapses in relation to the control group. Therefore, active retention time should be increased in the posttreatment period.

Treatment changes of hypo- and hyperdivergent Class II Herbst patients

OBJECTIVES

To determine the relative effects of Herbst appliance therapy in hypo- and hyperdivergent patients.

MATERIALS AND METHODS

The treated group included 45 growing Class II, division 1, patients treated with stainless steel crown Herbst appliances, followed by fixed edgewise appliances. The untreated control group consisted of 45 Class II, division 1, subjects, matched to the treated sample based on Angle classification, age, sex, and pretreatment mandibular plane angle (MPA). Subjects were categorized as hypo- or hyperdivergent based on their MPAs. Pre- and posttreatment cephalograms were traced and superimposed on cranial base and mandibular structures.

RESULTS

The primary effect of the Herbst in terms of maxillomandibular correction was in the maxilla. It significantly restricted maxillary growth, producing a "headgear effect." Mandibular treatment changes depended on divergence. Hyperdivergent patients experienced a deleterious backward true mandibular rotation with Herbst treatment. Hypodivergent patients, as well as untreated hypo- and hyperdivergent controls, underwent forward true mandibular rotation. However, hypodivergent chins did not advance any more than expected for untreated hypodivergent Class II patients.

CONCLUSIONS

Hypo- and hyperdivergent patients benefit from the Herbst's headgear effect. While the mandibular growth of hypodivergent patients overcomes the negative rotational effects, hyperdivergent patients undergo a deleterious backward mandibular rotation and increases in facial height.

Comparison of surgical and non-surgical orthodontic treatment approaches on occlusal and cephalometric outcomes in patients with Class II Division I malocclusions

BACKGROUND

This study aimed to examine end-of-treatment outcomes of severe Class II Division I malocclusion patients treated with surgical or non-surgical approaches. This study tests the hypotheses that occlusal outcomes (ABO-OGS) and cephalometric outcomes differ between these groups.

METHODS

A total of 60 patients were included: 20 of which underwent surgical correction and 40 of which did not. Cast grading of initial and final study models was performed and information was gathered from pre- to post-treatment cephalometric radiographs. The end-of-treatment ABO-OGS and cephalometric outcomes were compared to Mann-Whitney U tests and multivariable linear regression models.

RESULTS

Following adjustment for multiple confounders (age, gender, complexity of case, and skeletal patterns), the final deband score (ABO-OGS) was similar for both groups (23.8 for surgical group versus 22.5 for non-surgical group). Those treated surgically had a significantly larger reduction in ANB angle, 3.4° reduction versus 1.5° reduction in the non-surgical group (p = 0.002). The surgical group also showed increased maxillary incisor proclination (p = 0.001) compared to the non-surgical group. This might be attributed to retroclination of maxillary incisors during treatment selection in the non-surgical group-namely, extraction of premolars to mask the discrepancy.

CONCLUSIONS

Those treated surgically had a significantly larger reduction in ANB angle and increased maxillary incisor proclination compared to those treated non-surgically with no significant changes in occlusal outcomes.

Perception of changes in soft-tissue profile after Herbst appliance treatment of Class II Division 1 malocclusion

INTRODUCTION

In this study, we sought to assess the perception of changes in soft-tissue profile after Herbst appliance treatment by comparing facial profile silhouettes before treatment, immediately after treatment, and 2 years after treatment, as examined by orthodontists, general dentists, and laypersons.

METHODS

The sample comprised 21 patients (mean age, 9.5 ± 0.5 years), who were treated with the Herbst appliance for a mean period of 12 (±1.1) months. Three lateral cephalograms were obtained at different times: baseline, immediately after removal of the Herbst appliance, and 2 years after removal of the appliance. The 63 resulting profile silhouettes were evaluated by 120 examiners divided into 3 groups: orthodontists, general dentists, and laypersons. The examiners were instructed to choose their preferred profile and note how much change they perceived across profiles using a visual analog scale.

RESULTS

All groups of examiners preferred the posttreatment profiles. However, on quantitative assessment, the magnitudes of changes in the profile were found to be variable and rather small, with laypersons quantifying the greatest magnitude of change.

CONCLUSIONS

Early Herbst appliance treatment produced positive changes in the facial profile that were visually appreciable both immediately after removal of the appliance and 2 years after treatment.

Cephalometric study of Class II Division 1 patients treated with an extended-duration, reinforced, banded Herbst appliance followed by fixed appliances

INTRODUCTION

The Herbst appliance has been used in the treatment of Class II malocclusions with deficient mandibles. Various protocols, including different durations of the orthopedic treatment phase and stepwise advancement of the mandible, have been advocated for increasing the orthopedic effects. The objective of this study was to investigate the skeletal and dental changes in patients treated with a reinforced banded Herbst appliance for an extended duration and fixed appliance therapy.

METHODS

The study group consisted of 30 patients (16 boys, 14 girls; mean age, 12.3 ± 2.5 years) with Class II Division 1 malocclusions who were successfully treated with the new Herbst protocol followed by fixed appliances. Lateral cephalometric radiographs were taken before treatment, at the completion of Herbst treatment, and after removal of fixed appliances. The average treatment times were 1.5 ± 0.7 years for the Herbst treatment and 1.8 ± 0.5 years for the fixed appliances. A control Class II sample from the Bolton-Brush study was used to subtract growth from treatment changes to determine the appliance effect. Data were analyzed using analysis of variance and the Tukey-Kramer test.

RESULTS

After the Herbst treatment, the incisal relationships of all subjects had been overcorrected to end-to-end relationships. Overjet was reduced by 7.2 mm after subtracting changes from growth. The skeletal contribution was 2.5 mm (35%), and the dental contribution was 4.7 mm (65%). The molar relationship was overcorrected to a more Class I relationship by 7.5 mm. The Wits appraisal was improved by 4.2 mm. Vertically, overbite was decreased by 3.3 mm. The maxillary and mandibular molars were extruded by 1 mm. The occlusal plane rotated clockwise by 5° with little change in the mandibular plane angle. After the treatment with fixed appliances, the overjet correction was maintained at 7.6 mm. The skeletal contribution was 2.9 mm (38%), and the dental contribution was 4.7 mm (62%). The molar relationship was corrected to a Class I relationship by 5.9 mm. The Wits appraisal was improved by 3.2 mm. Vertically, overbite was decreased by 4.2 mm. The maxillary and mandibular molars were extruded by 0.3 and 0.8 mm, respectively. The occlusal plane rotated clockwise by 1.2° with little change in the mandibular plane angle.

CONCLUSIONS

Doubling the usual orthopedic treatment time with the reinforced Herbst appliance followed by fixed appliance therapy was effective in correcting Class II Division 1 malocclusions with excess overjet and overbite. In this sample of successfully treated patients, most changes after Herbst and fixed appliance therapy were dentoalveolar (62%). However, the skeletal changes attained in the orthopedic phase of treatment were maintained after fixed appliance therapy.

The effectiveness of the Herbst appliance for patients with Class II malocclusion: a meta-analysis

OBJECTIVE

To systematically investigate review in literature the effects of the Herbst appliance for patients with Class II malocclusion patients.

METHOD

We performed a comprehensive literature survey on PubMed, Web of Science, Embase, CENTRAL, SIGLE, and ClinicalTrial.gov up to December 2014. The selection criteria: randomized controlled trials or clinical controlled trials; using any kind of Herbst appliances to correct Class II division 1 malocclusions; skeletal and/or dental changes evaluated through lateral cephalograms. And the exclusion criteria: syndromic patients; individual case reports and series of cases; surgical interventions. Article screening, data extraction, assessment of risk of bias, and evaluation of evidence quality through GRADE were conducted independently by two well-trained orthodontic doctors. Consensus was made via group discussion of all authors when there is inconsistent information from the two. After that, sensitivity analysis and subgroup analysis were performed to evaluate the robustness of the meta-analysis.

RESULTS

Twelve clinical controlled trials meet the above-mentioned criteria, and were included in this analysis. All included studies have eleven measures taken during both active treatment effect and long term effect periods, including four angular ones (i.e., SNA, SNB, ANB, mandibular plane angle) and seven linear ones (i.e. Co-Go, Co-Gn, overjet, overbite, molar relationship, A point-OLp, Pg-OLp) during active treatment effect period were statistically pooled. Meta-analysis and sensitivity analysis demonstrated that all these measures showed consistent results except for SNA, ANB, and overbite. Subgroup analysis showed significant changes in SNA, overbite, and Pg-OLp. Publication bias was detected in SNB, mandibular plane angle, and A point-OLp.

CONCLUSION

The Herbst appliance is effective for patients with Class II malocclusion in active treatment period. Especially, there are obvious changes on dental discrepancy and skeletal changes on Co-Gn. As to its long-term effects, more evidence is needed to draw conclusions.

Treatment effects of a fixed intermaxillary device to correct class II malocclusions in growing patients

Background

The objective of this study was to evaluate the treatment effects of Forsus™ Fatigue Resistant Device (FRD; 3M Unitek, Monrovia, CA, USA) in growing patients with Class II non-extraction malocclusions.

Methods

A retrospective sample of 24 class II patients treated consecutively with the FRD followed by comprehensive orthodontic treatment was compared to a sample of untreated control subjects from the Bolton Brush Study who was matched in age, sex, and craniofacial morphology. Lateral cephalometric radiographs were taken before treatment (T1) and after removal of fixed appliances (T2). Growth changes were subtracted from the treatment changes to obtain the treatment effects of the appliance. Data were analyzed using ANOVA and a match paired t test.

Results

Significant differences were found between the treated and control groups for 12 of the 29 measured variables (Co-Gn minus Co-Apt, Wits, Is-OLp, Ii-OLp, overjet, Mi-OLp, molar relationship, overbite, Mic-ML, SNA, ANB, and Ii-ML). With 27.8 months of treatment, all patients were corrected to a class I dental arch relationship. Overjet and molar relationships were improved by an average of 4.7 and 3.1 mm, respectively. This was contributed by a 1.2 mm of restraint in forward maxillary growth, 0.7 mm of forward movement of the mandible, 1.5 mm of backward movement of the maxillary incisors, 1.3 mm forward movement of the mandibular incisors, 0.5 mm backward movement of the maxillary molars, and 1.3 mm of forward movement of the mandibular molars. The overbite was decreased by 2 mm with no significant change in the occlusal, palatal, or mandibular plane. Individual variations in response to the FRD treatment were large for most of the parameters tested. Significant differences in treatment changes between male and female subjects were found only in a few parameters measured.

Conclusions

These results demonstrate that significant overjet and overbite corrections can be obtained with the Forsus FRD in conjunction with comprehensive orthodontic treatment.

Comparison between an Acrylic Splint Herbst and an Acrylic Splint Miniscrew-Herbst for Mandibular Incisors Proclination Control

Aim. The aim of this study is to compare dental and skeletal effects produced by an acrylic splint Herbst with and without skeletal anchorage for correction of dental class II malocclusion. Methods. The test group was formed by 14 patients that were treated with an acrylic splint miniscrew-Herbst; miniscrews were placed between mandibular second premolars and first molars; controls also consisted of 14 subjects that were treated with an acrylic splint Herbst and no miniscrews. Cephalometric measurements before and after Herbst treatment were compared. The value of α for significance was set at 0.05. Results. All subjects from both groups were successfully treated to a bilateral Class I relationship; mean treatment time was 8,1 months in the test group and 7.8 in the controls. Several variables did not have a statistical significant difference between the two groups. Some of the variables, instead, presented a significant difference such as incisor flaring, mandibular bone base position, and skeletal discrepancy. Conclusions. This study showed that the Herbst appliance associated to miniscrews allowed a better control of the incisor flaring with a greater mandibular skeletal effect.

Three-dimensional treatment outcomes in Class II patients treated with the Herbst appliance: a pilot study

INTRODUCTION

The aims of this study were to analyze 3-dimensional skeletal changes in subjects with Class II malocclusion treated with the Herbst appliance and to compare these changes with treated Class II controls using 3-dimensional superimposition techniques.

METHODS

Seven consecutive Herbst patients and 7 Class II controls treated with Class II elastics who met the inclusion criteria had cone-beam computed tomographs taken before treatment, and either after Herbst removal or at posttreatment for the control subjects. Three-dimensional models were generated from the cone-beam computed tomography images, registered on the anterior cranial bases, and analyzed using color maps and point-to-point measurements.

RESULTS

The Herbst patients demonstrated anterior translation of the glenoid fossae and condyles (right anterior fossa, 1.69 ± 0.62 mm; left anterior fossa, 1.43 ± 0.71 mm; right anterior condyle, 1.20 ± 0.41 mm; left anterior condyle, 1.29 ± 0.57 mm), whereas posterior displacement predominated in the controls (right anterior fossa, -1.51 ± 0.68 mm; left anterior fossa, -1.31 ± 0.61 mm; right anterior condyle, -1.20 ± 0.41 mm; left anterior condyle, -1.29 ± 0.57 mm; P <0.001). There was more anterior projection of B-point in the Herbst patients (2.62 ± 1.08 mm vs 1.49 ± 0.79 mm; P <0.05). Anterior displacement of A-point was more predominant in the controls when compared with the Herbst patients (1.20 ± 0.53 mm vs -1.22 ± 0.43 mm; P <0.001).

CONCLUSIONS

Class II patients treated with the Herbst appliance demonstrated anterior displacement of the condyles and glenoid fossae along with maxillary restraint when compared with the treated Class II controls; this might result in more anterior mandibular projection.

Comparison between Herbst appliances with or without miniscrew anchorage

Background:

Herbst appliance is largely used in orthodontics for the correction of Class II. The aim of this paper was to analyze dental and skeletal effects of a splints Herbst-miniscrews combined device in comparison to a mandibular splints Herbst appliance.

Materials and Methods:

Fifty Class II division 1 patients (27 males and 23 females with a mean age of 11.8 ± 1.7 years) were included in the study. Lateral headfilms of 25 patients with a mandibular resin splint and a miniscrew anchorage (test group) and of 25 patients with mandibular acrylic resin splints (control group) were analyzed before (T0) and after (T1) the Herbst treatment. The mean and standard deviation (SD) of each variable were calculated; paired t-test was used to evaluate statistical changes before and after the treatment, in each group and Student t-test was used to compare the two groups.

Results:

Significant differences were observed for P < 0.05. At the end of the Herbst treatment, mandibular incisor proclination was significantly lower in the test group (2.8°) in comparison to the control group (7.4°).

Conclusions:

The miniscrew-Herbst system, described in the present study, allows correction of Class II malocclusion, with a lower anchorage loss, in form of mandibular incisor proclination, during the treatment, in comparison to mandibular acrylic splints Herbst.