Modified Herbst Approach for Overbite

Overseen By Nancy Abdelhay, PhD

Age: < 18

Sex: Any

Trial Phase: Academic

Sponsor: University of Alberta

Disqualifiers: Surgery, Mixed dentition, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

Duration: 1 year

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores two methods to correct overbites using the Herbst appliance, which aligns teeth and jaws. The study compares the Conventional Herbst Approach, using only the appliance, with a modified method that adds small screws for extra support. The goal is to determine which approach more effectively changes facial, teeth, and bone structure. Individuals with a specific type of overbite and fully developed adult teeth, who do not require surgery, may be suitable candidates. As an unphased trial, this study allows participants to contribute to advancing dental treatment options and improving outcomes for future patients.

Do I have to stop taking my current medications for this trial?

The trial protocol does not specify whether you need to stop taking your current medications. It seems focused on orthodontic treatments, so it's unlikely that medications would be affected, but you should confirm with the trial organizers.

What prior data suggests that these orthodontic approaches are safe?

Research has shown that the Modified Herbst Approach is generally well-tolerated. In one study, 71.4% of patients experienced no complications during treatment. While some patients did encounter issues, these were uncommon. Specifically, difficulties with the device staying attached occurred in 8 out of 13 reported cases.

The Modified Herbst device is designed for comfort and ease of cleaning. However, some patients found it less stable in their mouths, which could be a downside since stability helps keep the device in place. Overall, most patients using the Modified Herbst Approach did not experience major problems, indicating it is relatively safe. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the modified Herbst approach for treating overbite because it incorporates temporary anchorage devices (TADs) in both arches, which is not a feature of the conventional Herbst treatment. These TADs provide additional stability and support, potentially leading to more effective and precise tooth movement. The addition of elastomeric chains to connect the TADs to molars and canines further enhances this stability, offering a more controlled and customizable treatment process. This modification aims to improve outcomes for patients with Class II malocclusion by addressing specific dental needs with greater accuracy.

What evidence suggests that this trial's treatments could be effective for overbite?

Research has shown that the Herbst appliance effectively treats Class II malocclusion, a common dental issue where the upper teeth protrude over the lower teeth. Studies have found that the Herbst appliance can significantly improve the alignment of teeth and jaw. In this trial, participants will receive either a conventional hybrid Herbst appliance or a modified version that uses temporary anchorage devices (TADs) for enhanced stability and effectiveness. Early results suggest that patients experience noticeable improvements in their dental and facial appearance. Overall, the Herbst appliance, in its various forms, has been linked to successful corrections of dental misalignments. ^{2 6 7 8 9}

Who Is on the Research Team?

Carlos Flores Mir, DSc

Principal Investigator

University of Alberta

Are You a Good Fit for This Trial?

This trial is for individuals with a specific dental condition called Class II skeletal malocclusion, where the lower jaw and teeth are significantly behind the upper ones. They should have all permanent teeth and no missing congenital teeth. It's not suitable for those who only qualify for surgical treatment or don't have at least an end-to-end molar relationship.

Inclusion Criteria

Class II skeletal malocclusion based on PgOLp more than 85 mm and A-OLp more than 75 mm

Early permanent dentition

Perceived potential improvement of facial convexity

Exclusion Criteria

My back teeth do not align properly.

Class II skeletal malocclusion based on PgOLp less than 85 mm and A-OLp less than 75 mm

Mixed dentition

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Treatment

Participants receive either a hybrid Herbst appliance approach or a modified hybrid Herbst appliance approach with TADs

1 year

Regular visits as per orthodontic treatment schedule

Follow-up

Participants are monitored for changes in facial, dental, and skeletal structures, as well as quality of life assessments

4 weeks

2 visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Conventional Herbst Approach
• Modified Herbst Approach

Trial Overview

The study compares two orthodontic treatments to correct overbites: one uses the Modified Herbst device followed by braces, while the other adds bone screws before using the Herbst device and then braces. The goal is to see which method better improves chin projection and alignment of teeth.

How Is the Trial Designed?

Group I: Class II type B malocclusion - proclination of upper incisors not indicated - TADs Experimental Treatment 1 Intervention

CA modified hybrid Herbst appliance approach (same hybrid Herbst appliance approach but with the addition of temporary anchorage devices (TADs) in both arches) will be used (alternative treatment). In the upper arch, the TADs would be inserted in the paramedical palatal area. In the lower arch, they would be inserted buccally between the roots of the lower second premolar and the first permanent molar. Elastomeric chains will be used to link these TADs to the first molars in the upper arch and to a buccal bottom on the lower canines.

Group II: Class II type A malocclusion - proclination of upper incisors indicated - TADs Experimental Treatment 1 Intervention

A modified hybrid Herbst appliance approach (same hybrid Herbst appliance approach but with the addition of temporary anchorage devices (TADs) in both arches) will be used (alternative treatment). In the upper arch, the TADs would be inserted in the paramedical palatal area. In the lower arch, they would be inserted buccally between the roots of the lower second premolar and the first permanent molar. Elastomeric chains will be used to link these TADs to the first molars in the upper arch and to a buccal bottom on the lower canines. Upper brackets will be initially bonded and upper incisors proclined until normal inclination values are attained.

Group III: Class II type A malocclusion - proclination of upper incisors indicated - No TADs Active Control 1 Intervention

A hybrid Herbst appliance approach will be used (current available conventional treatment). The upper jaw component will be a maxillary expander secured on the first molar bands. The lower arch would have an uncemented lower acrylic full-coverage splint-type. In between Herbst-type pistons will be used. Upper brackets will be initially bonded and upper incisors proclined until normal inclination values are attained.

Group IV: Class II type B malocclusion - proclination of upper incisors not indicated - No TADs Active Control 1 Intervention

A hybrid Herbst appliance approach will be used (current available conventional treatment). The upper jaw component will be a maxillary expander secured on the first molar bands. The lower arch would have an uncemented lower acrylic full-coverage splint-type. In between Herbst-type pistons will be used.

Conventional Herbst Approach is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Herbst Appliance for:

• Class II malocclusions
• Overbites
• Improvement of chin projection

Approved in European Union as Herbst Device for:

• Orthodontic treatment for Class II malocclusions
• Correction of overbites
• Enhancement of chin projection

Approved in Canada as Herbst Appliance for:

• Treatment of Class II malocclusions
• Improvement of overbites
• Chin projection enhancement

Who Is Running the Clinical Trial?

University of Alberta

Lead Sponsor

Trials

957

Recruited

437,000+

Published Research Related to This Trial

In a study comparing 46 adults who underwent orthognathic surgery with 23 adults treated with the Herbst appliance, both methods successfully achieved Class I occlusion, indicating that Herbst treatment can be a viable alternative to surgery for certain patients.

While both treatments reduced facial profile convexity, the surgery group achieved greater skeletal changes, suggesting that Herbst treatment is effective for occlusal correction but may be less effective for significant facial profile improvements.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Orthognathic surgery and dentofacial orthopedics in adult Class II Division 1 treatment: mandibular sagittal split osteotomy versus Herbst appliance. Ruf, S., Pancherz, H.[2019]

The Herbst appliance significantly intruded the mandibular incisors and maxillary molars while allowing mandibular molars to erupt, effectively reducing deep anterior overbite and increasing lower facial height in 22 treated cases over six months.

While the Herbst appliance had a limited impact on the overall vertical position of the jaws, some patients experienced notable changes, such as posterior rotation of the maxillary complex, highlighting the need for careful treatment planning and retention strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Vertical dentofacial changes during Herbst appliance treatment. A cephalometric investigation. Pancherz, H.[2022]

In a study of 208 patients with Class II malocclusion, the HT Herbst appliance showed a lower risk of emergencies compared to the acrylic splint Herbst, which had an emergency probability twice as high.

Both types of Herbst appliances had similar treatment times and retreatment probabilities, but the HT Herbst had a higher failure frequency, suggesting that while it may be more reliable in emergencies, it could be less effective overall compared to the traditional acrylic splint.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acrylic splint Herbst and Hanks telescoping Herbst: a retrospective study of emergencies, retreatments, treatment times and failures. Manni, A., Cozzani, M., Mazzotta, L., et al.[2016]

The Herbst appliance is highly effective for treating Class II malocclusions in growing patients, as demonstrated by clinical cases followed for up to 5 years, but should not be used as a last resort.

Successful outcomes are best achieved in patients with a brachyfacial growth pattern, and post-treatment retention is essential to prevent occlusal relapses after the appliance is removed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Herbst appliance--its biologic effects and clinical use. Pancherz, H.[2022]

In a study of 30 patients with Class II Division 1 malocclusions, extending the treatment duration with a reinforced Herbst appliance effectively corrected overjet and molar relationships, achieving significant skeletal and dental changes.

After transitioning to fixed appliance therapy, the improvements in overjet and molar relationships were maintained, indicating that the skeletal changes from the Herbst treatment were preserved, with most corrections being dentoalveolar.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cephalometric study of Class II Division 1 patients treated with an extended-duration, reinforced, banded Herbst appliance followed by fixed appliances. Tomblyn, T., Rogers, M., Andrews, L., et al.[2017]

The study involved 10 adolescents with skeletal class II malocclusions, comparing a modified Herbst appliance with temporary anchorage devices (TADs) to a conventional Herbst appliance over a 9-month treatment period.

Results showed that the modified appliance significantly reduced lower incisor proclination, with only a 1° increase in inclination compared to a 7° increase in the conventional group, suggesting that TADs enhance treatment efficiency and skeletal response.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mini-implants and the efficiency of Herbst treatment: a preliminary study. Luzi, C., Luzi, V., Melsen, B.[2021]

The Herbst-Multibracket appliance (Herbst-MBA) treatment significantly improved the occlusion of Class II:2 malocclusion patients, with the average Peer Assessment Rating (PAR) score decreasing from 23.6 to 5.6 after treatment, indicating effective orthodontic correction.

After a follow-up period of over 2 years, the treatment results remained stable, with 30% of patients rated as 'greatly improved' post-treatment and 33% after follow-up, demonstrating the long-term efficacy of the Herbst-MBA.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficiency and outcome quality of Herbst-Multibracket appliance therapy in Class II:2 patients. Bock, NC., Killat, S., Ruf, S.[2022]

A treatment protocol involving 12 months of stepwise advancement with the Herbst appliance followed by fixed appliances was effective in achieving stable correction of overjet and molar relationships in 16 Class II adult patients.

The study suggests that the long-term stability of the treatment outcomes is significantly influenced by the specific treatment protocol used, emphasizing the importance of a structured approach for mandibular advancement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A protocol for improved stability with Herbst appliance treatment for adults. Austin, DF., Chaiyongsirisern, A., Yang, Y., et al.[2013]

This study will evaluate a new Herbst appliance design combined with temporary anchorage devices (TADs) to control vertical growth in hyperdivergent Class II patients, aiming to reduce unwanted clockwise rotation of the occlusal plane compared to traditional Herbst treatment.

A total of 44 children will be randomly assigned to receive either standard Herbst treatment or the new approach, with the primary outcome measured through cephalometric analysis of the occlusal plane, ensuring a rigorous assessment of efficacy and safety.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy of an innovative Herbst appliance with TADs for patients with hyperdivergent class II malocclusion: study protocol for a randomised controlled trial. Wang, Y., Xu, Y., Gong, Z., et al.[2023]

The study analyzed the effects of the Herbst device on 75 growing patients with class II malocclusion, revealing that treatment responses varied based on vertical facial growth patterns.

Hypodivergent patients showed an increase in mandibular divergence during treatment, while hyperdivergent patients experienced a decrease, indicating that facial growth patterns significantly influence the effectiveness of the Herbst appliance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of Vertical Facial Growth Pattern on Herbst Appliance Effects in Prepubertal Patients: A Retrospective Controlled Study. Giuca, MR., Pasini, M., Drago, S., et al.[2022]

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Modified Herbst Approach to Improve Chin Projection

The present study will compare facial, skeletal, and dental changes among adolescents with mild to moderate Class II malocclusion using two Class II orthopedic ...

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The aim of this study was to evaluate the effects of the Manni Telescopic Herbst (MTH) appliance in young patients with mixed dentition, ...