CLINICAL TIPS & TECHNIQUES

Class II Correction with Simultaneous Invisalign® and the Herbst ApplianceBy Dr. Barry J. Glaser, DMD

Review of Literature

While there are advocates of different Class II techniques, there

is a considerable amount of literature that supports the viewpoint

that treatment outcomes are quite similar regardless of the

appliance or technique employed.

In 1985, Adenwalla and Kronman1, in a study comparing

treatment with the Frankel appliance to that of edgewise

appliances, found that treatment results were similar in both

groups with no overall difference in mandibular growth.

Remmer, Mamandras, Hunter and May2, in 1985, studied

cephalometric changes associated with treatment using the

activator, the Frankel appliance and the fixed appliances and

found clinically insignificant differences in treatment outcomes

between the three treatment modalities.

A recent meta analysis3 of 11 research articles concluded

that treatment outcomes with both Class II elastics and fixed

functional appliances were similar with regards to long term

effectiveness, and that for both methods the effects are primarily

dentoalveolar.

Given that the literature supports the concept that successful

treatment results may be achieved with either Class II elastics

or functional appliances, some practitioners may find that

removing patient compliance with elastics by using the Herbst

is advantageous.

Why use Invisalign with Herbst Appliance?

The specific advantages to using the Herbst appliance with

Invisalign rather than brackets and wire in the teen patient is

the ability to predictably gain sagittal correction with the Herbst

while simultaneously enjoying all of the esthetic, hygienic and

efficiency benefits of Invisalign treatment. Less frequent patient

visits and fewer emergencies increase profitability and patient

satisfaction drives increased patient referrals.

For those practitioners concerned about teen patient’s

compliance with Invisalign, it has been my overwhelming

experience that this simply is not an issue. Greater than 95% of

my Invisalign Teen patients wear their aligners as instructed. Is it

magic? No. It’s psychology. Teens comply with Invisalign better

than braces because we instruct our patients that we will have

no choice but to switch them to braces if they don’t follow our

instructions. They appreciate the esthetic and social benefits of

clear aligner therapy and are happy to follow the rules.

Advansync® Herbst and Invisalign

Feasibility of Combined Herbst/Invisalign Treatment

For many practitioners, the approach to Class II cases is to first

treat the Class II malocclusion in the mixed dentition, and then

treat the patient in a second phase in the early permanent

dentition with Invisalign. But what happens if the patient

presents for the first time as an adolescent in the permanent

dentition? Is it necessary to spend 12-18 months in a Class II

corrector, then an additional 12-18 months in Invisalign? What if

we could simultaneously level and align the arches with Invisalign

and use the Herbst appliance, as is done with Dischinger type

edgewise/Herbst treatment? In this scenario, treatment

becomes more efficient and treatment times are shortened.

This approach may be used for any Class II case you would

consider to be non-surgical and non- extraction. This

encompasses mild to severe sagittal discrepancies, as well

as both bilateral and unilateral cases. I personally do not use

this technique on non-growing adult patients. Furthermore,

there is a body of literature that supports the idea that the

Herbst appliance is not a “mandible grower.” In cases of

severe mandibular retrognathism, the patient and parents

should be counselled on the differences between the primarily

dentoalveolar effects of the Herbst appliance versus the more

predictable improvement in chin position that may be achieved

with orthognathic surgery.

Technique

We will explore the specific steps needed to manage this case

as well as some of the lessons learned to make management of

future patients even more efficient and predictable.

1. Order Advansync® Herbst appliance

Take a set of alignate impressions for Herbst manufacture.

Submit the study models and completed prescription to the

lab for the Herbst. We use AOA lab to fabricate an Advansync

Herbst as this appliance connects to the upper and lower first

molars only, plus, there are no lower cantilevers to obstruct the

insertion and removal of the aligners.

• Request overcorrection of the Class II malocclusion to at least

edge to edge in the Herbst, since some degree of Class II

relapse is to be expected once the Herbst is removed.

• Request the lower molar band to be connected with a lingual

arch placed directly at the gingival margin to prevent mesial-

in rotation of the lower molars during treatment. It is not

necessary to connect the upper molar bands as mesial out

rotation is generally desired to improve the upper and lower

molar relationships.

2. Submit Invisalign records and modify ClinCheck® treatment plan

Take either PVS impressions or an iTero scan for aligner

manufacture. Modify the ClinCheck treatment plan as follows:

• Request that both upper and lower aligners terminate at the

distal aspect of the upper and lower second premolars. This is

necessary as the upper and lower first molars will be banded

and not included in the Invisalign appliance.

• Request 10 degrees of labial root torque in the lower incisors

to counter the lower incisor proclination effect of the Herbst.

• Request that the lower aligner be trimmed slightly incisal to

the lower gingival margin to accommodate the lingual arch.

• The typical time to achieve CL I with the Herbst appliance is

9-12 months. Be sure to request enough aligners (at least

26 stages) to last that long.

3. Insert Herbst and Invisalign

One week before insertion of the initial aligners and Herbst,

schedule a brief appointment to place upper and lower

first molar separators. Any minor tooth movement from the

separators will not affect aligner fit.

• On the day of insertion, first remove the separators.

• Then proceed to place all attachments before insertion of the

Herbst to facilitate ease of placing cheek retractors and other

means of isolation.

• Once the attachments are placed, cement the Herbst, install

the right and left telescopes, and shim as necessary to achieve

edge to edge anterior occlusion and coincident upper and

lower midlines.

• Following this, insert the first set of aligners and provide

patient instructions as usual. The Advansync Herbst is

generally well tolerated with minimal soft tissue impingement

or irritation. Nevertheless, we give the patient wax and zilactin

in case there are sore spots during the first few days.

CLINICAL TIPS & TECHNIQUES

ClinCheck

4. Plan for refinement and elastics wear

Once the Herbst is removed, it is very important to prescribe Class II Precision Cuts

in the refinement aligners. We keep our patients on light Class II elastics for the first

several months worn to Precision Cut hooks on the upper canines and lower first molars

to ensure a solid Class I relationship. Gradually reduce elastic wear to nights only for

3 months to be certain the patient has not relapsed back to a mild Class II. After 3 months

of night time Class II elastic wear and confirmation that the patient is still Class I, elastics

may be discontinued and the case can be finished as usual.

Tips for Appointments

Appointments may be scheduled at the same interval as your typical Invisalign patients.

In our office that is generally once every 12 weeks. At each adjustment appointment,

check aligner fit as well as the overjet. Shim the Herbst as necessary to maintain

2-3 mm overcorrection.

Herbst and Invisalign Means Efficiency and Profitability

The lab fee for the Herbst is approximately $225-$250. While it is an extra expense,

considerable chair time may be saved using Invisalign and the Herbst. We see our

patients once every 12 weeks for a brief visit to monitor aligner tracking and Herbst

adjustment. Adding a shim to the Herbst takes a few seconds. Fewer patient visits and

efficient treatment allows cases to be finish more rapidly, further increasing the

profit per visit equation. Furthermore, less chair time per patient means the schedule

opens up to allow less waiting time for new patient exams and starts, and allows

streamlining of overhead related to excessive staffing.

1 Adenwalla and Kronman, Angle Orthod. 55, 281-298, 1985. Class II Div 2 treatment with Frankel and Edgewise appliances. 2 Remmer, Mamandras, Hunter and May, AJODO vol 88, 1985. Cephalometric changes associated with treatment using the activator, the frankel appliance and the fixed appliance.3 Pancherz AJODO 87:1-20, 1985. The Herbst appliance: it’s biological effects and clinical use.

Align Technology, Inc.2560 Orchard PkwySan Jose, CA 95131

WWW.INVISALIGN.COM

CLINICAL TIPS & TECHNIQUES

© 2013 Align Technology, Inc. All rights reserved. Invisalign and ClinCheck, among others, are registered trademarks of Align Technology, Inc. All other trademarks are the property of their respective owners.M20255 Rev A June 2013

Disclosure: Dr. Barry J. Glaser was provided an honorarium from Align for his article. The statements, views and opinions expressed in this article are those of the author, and do not necessarily reflect the views and opinions of Align Technology, Inc.

DR. BARRY J. GLASER

Dr. Glaser received a B.A. in psychology from Binghamton

University in 1984 and was awarded his Dental Degree from the

University of Pennsylvania School of Dental Medicine in 1988.

He then completed a one-year hospital residency at Englewood

Hospital in 1989 and went on to earn his Specialty Certification

in Orthodontics from Boston University School of Graduate

Dentistry in 1992. He is also involved in orthodontic education.

He was Associate Director of orthodontics at Montefiore Medical

Center in New York from 1992 to 1995 and gives lectures on

orthodontics throughout the United states and Canada.

Dr. Glaser is an Invisalign Elite Preferred provider and maintains

his private orthodontic practice in Cortlandt Manor, New York.