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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.