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

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.

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

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

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

RESULTS

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

CONCLUSION

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

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

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

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.

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.

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.

Dental changes induced by a modified Herbst appliance followed by fixed appliances: A digital dental model analysis

BACKGROUND

Herbst therapy is an effective treatment for Class II malocclusions. However, the maintenance of the effects after fixed appliances treatment remains questionable. This retrospective study aimed to assess, using digital dental models, the sagittal and transverse dental arch changes in young patients during two Class II Division 1 treatment phases, first with modified Herbst appliance (HA) and then with fixed appliances.

METHODS

The treated group (TG) comprised 32 patients (17 boys, 15 girls; mean age, 12.85 ± 1.16 years) treated with HA and fixed appliances. The control group comprised 28 patients (13 boys, 15 girls; mean age, 12.21 ± 1.35 years) with untreated Class II malocclusions. Digital models were obtained immediately before and after HA therapy and after fixed appliances. Data were statistically analyzed.

RESULTS

Compared with the control group, the TG showed an increase in maxillary and mandibular arch perimeters and in intercanine and intermolar arch widths, a decrease in overjet and overbite, and an improvement in canine and molar relationships. In the time after HA therapy until the end of fixed appliances treatment, the TG showed a decrease in maxillary and mandibular arch perimeters, overjet, upper and lower intermolar widths; an increase in molar Class II relationship; and no changes in canine relationship, overbite, and upper and lower intercanine widths.

CONCLUSIONS

In this sample of patients treated with HA, on average, there was an improvement in the Class II relationship, which seemed to remain after fixed appliances. The transverse dental changes achieved in HA phase relapsed after treatment with fixed appliances.

Does mandibular advancement with clear aligners have the same skeletal and dentoalveolar effects as traditional functional appliances?

BACKGROUND

The study aimed to compare the dentoskeletal effects of Vanbeek Activator, Herbst, Twin-Block and Mandibular Advancement with clear aligners in children with skeletal Class II malocclusions.

METHODS

A sample with sixty-three patients (37 males, 26 females) was included and divided into untreated control group (C, n = 12), Vanbeek Activator group (V, n = 14), Herbst group (H, n = 11), Twin-Block group (TB, n = 12) and MA group (MA, n = 14). Cephalometric analysis and Johnston Pitchfork analysis were performed to quantify the skeletal and dentoalveolar components in molar relationship and overjet correction. Compare the differences of cephalometric data and Johnston-analysis data.

RESULTS

The treatment changes showed significant differences in SNB, FH-NP, NA-PA, Co-Go, Co-Pog, ANB, lower facial height ratio, U1-PP, U6-PP, L1-MP and U1-L1. All the appliances improved overjet relationships significantly (Vanbeek, Herbst, Twin-Block and MA were 2.77 mm, 5.53 mm, 4.73 mm and 3.66 mm respectively) with significant retraction of maxillary incisors. The lower incisor displacement of group V and MA was negative, while that of group H and TB was positive and there were significant differences. Molar relationships were also improved by 3.45 mm, 6.85 mm, 3.48 mm and 0.92 mm for Vanbeek, Herbst, Twin-Block and MA. Mandible displacement showed a trend of group H > TB > V > MA. The displacement of maxillary molars in group H was greater than that in group C, TB and MA, and that of mandibular ones was greater than that in group C, V and MA, significantly. Herbst, Twin-Block and MA have more significant dentoalveolar effect than Vanbeek, while Vanbeek has more skeletal effect than the others especially in restraining maxillary growth.

CONCLUSIONS

Four appliances are all effective in mandibular advancement, modification of class II molar relationship and deep overjet, with unavoidable increase in lower facial ratio. Vanbeek Activator has the most skeletal effects. Vanbeek and MA have a good control of mandibular incisors while more compensatory lower incisors proclination in Herbst and Twin-Block. Herbst has greater maxillary molar distalization. MA allows aligning and leveling meanwhile leading the mandible forward.

Evaluation of the stability of treatment with Herbst appliance associated with Hyrax expander and fixed orthodontics through counterpart analysis: A longitudinal follow-up study

OBJECTIVE

The aim of this study was to evaluate the stability of treatment with a Herbst appliance associated with Hyrax expander (Stage I), followed by fixed appliances (Stage II) and follow-up for an average of 4 years after Stage II, on dentoskeletal facial structures.

METHODS

This study involved 50 adolescents with Angle Class II division 1 malocclusion associated with mandibular retrognathism: Treated Group (TG-25) and Control Group (CG-25). Lateral cephalometric radiographs were taken: T1, immediately before Stage I (TG) or at the beginning of the follow-up period (CG); T2, at the end of Stage I (TG) or the follow-up period (CG); T3, at the end of Stage II (TG); and T4, on average, 4 years after Stage II (TG). Enlow's counterpart analysis and some cephalometric measurements were evaluated. Parametric and non-parametric tests were used (P ≤ 0.05).

RESULTS

The ramus alignment variables (P < 0.001), SNB (0.040), ANB (<0.001), 1.PP (P = 0.015), 1.MP (P < 0.001), ms/RLp (P < 0.001), mi/RLp (P < 0.001) and S-LS (P = 0.005) showed differences between TG and CG from T1 to T2. Longitudinally, there were differences in ramus alignment, P = 0.003, T1 > T2 < T3 = T4; SNB, P = 0.016, T1 < T2 = T3 = T4; ANB, P < 0.001, T1 > T2 = T3 = T4; 1.MP, P < 0.001, T1 < T2 = T3 = T4; ms/RLp, P = 0.002, T1 = T2 < T3 = T4; mi/RLp, P < 0.001, T1 < T2 = T3 = T4; S-LS, P < 0.001, T1 > T2 = T3 = T4 and S-LI, P = 0.003, T1 = T2 = T3 > T4.

CONCLUSION

The nasomaxillary complex (MCF/PM alignment) tended to a retrusive effect to compensate the degree of mandibular retrusion. The protrusive effect of the lower facial third was evident after the Herbst stage and did not remain stable in the follow-up. The dentoalveolar compensation and improvement in facial profile remained stable.

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.

Three-dimensional skeletal and dentoalveolar sagittal and vertical changes associated with cantilever Herbst appliance in prepubertal patients with Class II malocclusion

INTRODUCTION

This study aimed to assess sagittal and vertical skeletal and dentoalveolar changes through the use of 3-dimensional imaging in prepubertal Class II malocclusion patients treated with a cantilever Herbst appliance (HA). Condyle-glenoid fossa positional changes were also quantified.

METHODS

This retrospective cohort study assessed 22 children (11.2 years ± 1.2) consecutively treated with a cantilever HA for 12 months and 11 untreated children (aged 9.3 ± 0.30 years) that served as controls. Cone-beam computed tomography was performed at baseline (T1) and at the end of the observation period (T2). Movements in the regions of interest were measured as linear displacements from cone-beam computed tomography images through algebraic calculations. A Student t test for independent samples was used for group equivalence testing at T1, and the treatment differences between T2 and T1 were evaluated by 2 analyses of covariance, one considering the expected growth unit as a covariate and the other with an annualized factor.

RESULTS

The largest dental movement was a mesial movement of mandibular molars (3.70 mm), whereas the largest skeletal changes consisted of a larger relative length of the mandible (difference of 1.2 mm) in the HA group than in the control group.

CONCLUSIONS

Within the study limitations (retrospective cohort, historical control group, and sample size), 3-dimensional imaging suggests that HA corrected Class II malocclusion in a predominantly prepubertal sample through more dental than skeletal changes. The changes were more significant in the sagittal than in the vertical direction. In addition, relative stability in the condyle-fossa relationship was noted.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Influence of incisor position control on the mandibular response in growing patients with skeletal Class II malocclusion

INTRODUCTION

This study aimed to test whether control in maxillary and mandibular incisor position, during treatment with an acrylic splint Herbst appliance, could influence the mandibular response in growing patients with skeletal Class II malocclusion.

METHODS

The lateral cephalograms of 61 patients (mean age, 12.3 years; standard deviation, 1.6) with skeletal and dental Class II malocclusion were retrospectively analyzed both at baseline and after Herbst appliance removal, using a modified Pancherz cephalomeric analysis. Forty-five patients had received miniscrew in the mandibular arch to control mandibular incisor anchorage. In 21 patients, the maxillary incisors had been proclinated before starting the treatment for deepbite and maxillary incisor lingual inclination. All the patients were categorized a posteriori into 2 homogeneous groups, according to dental overjet reduction: 30 patients with dental overjet reduction (DR) and 31 patients without dental overjet reduction (NDR).

RESULTS

Both groups presented a significant skeletal correction. However, the change was significantly greater in the NDR group than in the DR group (P <0.01). The mandibular bone base reached a median value of 4.0 mm (interquartile range, 2.5) in the NDR group vs 1.1 mm (interquartile range, 2.8) in the DR group (P <0.001). The 2 groups were also significantly different in terms of the positional change of maxillary incisor, which was proclinated in group NDR and lingualized in group DR (P <0.001).

CONCLUSIONS

The results showed that dental control of overjet was beneficial to improve the effectiveness of Herbst treatment in increasing mandibular length in growing patients with skeletal Class II malocclusion.

Evaluation of Profile Changes in Class II Individuals Treated by Means of Herbst Miniscope Appliance

Background: To evaluate the profile changes following orthopedic/orthodontic treatment with the Herbst Miniscope^® appliance in subjects affected with Class II malocclusion with mandibular retrusion. Methods: A total of 44 patients presenting a skeletal Angle Class II malocclusion (ANB > 4°) due to mandibular retrusion and a cervical maturation stage between CS2 and CS3 were included in the study. Of these 44 patients, 22 (mean age 11.9 ± 1.3, HBT group) were treated using the Herbst appliance, while 22 (mean age 10.6 ± 1.3, CTR group) were followed for a 12-month observational period. A cephalometric tracing was performed at the beginning of treatment (T0) and after 12 months (T1). Results: In both groups there was a significant advancement of soft tissue pogonion (HBT = 3.5 ± 3.0 mm, p < 0.001; CTR = 2.2 ± 2.9 mm, p < 0.001), but the difference between the two groups was not significant (p = 0.172). On the contrary, both groups had a significant advancement of the mandibular sulcus (HBT = 3.7 ± 2.8 mm, p < 0.001; CTR = 1.2 ± 2.2 mm, p < 0.001) and a lower lip protrusion (HBT = 3.45 ± 2.51 mm, p < 0.001; CTR = 1.7 ± 2.7 mm, p = 0.008), but in both cases the HBT group showed a statistically significant greater increase in sulcus protrusion (p = 0.002) and lower lip protrusion (p = 0.029) than controls. There were no statistically significant effects on the upper jaw. Conclusions: The Herbst appliance advanced the lower jaw soft tissues.

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.

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.

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.

Patient with Severe Skeletal Class II Malocclusion: Double Jaw Surgery with Multipiece Le Fort I

A 22-year-old woman with severe skeletal Class II malocclusion was referred to our clinic. A clinical examination revealed a convex soft tissue profile and increased teeth and gingiva exposure both while smiling and in the natural rest position. She had Class II molar and canine relationship with increased overjet, moderate crowding in both upper and lower jaws, and proclined upper and lower incisors. Skeletally, she showed transverse maxillary deficiency, maxillary vertical excess, and mandibular retrognathia. We planned orthodontic-orthognathic surgery with multipiece Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSO) to achieve ideal occlusion, stability, and facial esthetics. During orthodontic decompensation to relieve the crowding and to gain an ideal incisor inclination, four bicuspid extractions were performed. Because we used continuous mechanics, at the end of the decompensation period, we cut the maxillary arch wire distal to the lateral incisors into three pieces and waited for 3 months for vertical and transversal dental relapse. During the double jaw surgical procedure, the maxilla expanded and impacted with multisegmented Le Fort I osteotomy and the mandible advanced with BSSO. After the orthodontic and orthognathic surgical treatment, the skeletal and dental imbalance was corrected, and functional occlusion and dental and skeletal Class I relationship were achieved. The treatment results were stable at the 1-year follow-up.

Comparison of complications in the conventional telescopic Herbst rod and tube and Manni telescopic Herbst: A retrospective clinical study

OBJECTIVES

To compare the prevalence of clinical complications between two different telescopic Herbst systems: the conventional telescopic system, with traditional rod and tube (RMS), and the Manni telescopic Herbst appliance (MTH).

MATERIALS AND METHODS

Ninety subjects treated with RMS were compared to 89 patients treated with MTH. All of the complications that occurred were reported, and percentages of prevalence were calculated.

RESULTS

MTH showed a significantly lower percentage of reversible complications (that did not require appliance removal) when compared to the reversible complications during RMS treatment (20.2% vs 51.1%). No statistically significant differences were found between RMS and MTH regarding irreversible complications (that required appliance removal and full re-make). All of the irreversible complications occurred after reversible complications in the RMS group, while most of the irreversible complications in the MTH group occurred without any previous reversible complication.

CONCLUSIONS

MTH exhibited a smaller number of clinical complications during Class II skeletal malocclusion therapy.