Herbst appliance & its modifications

HERBST APPLIANCE & ITS
MODIFICATIONS
www.indiandentalacademy.com

INTRODUCTION
Functional appliances developed primarily in Europe by many
clinicians in an affort to stimulate mandibular growth, and
aid in the correction of skeletal class-2 malocclusions.
Lack of success with functional appliances has been attributed
to lack of patient coperation in appliance wear and inability to
control the amount and direction of mandibular growth.
HERBST appliance designed by EMIL HERBST in 1905 and
reintroduced by PANCHERZ attempts to adress these
problems of patient non-compliance.www.indiandentalacademy.com

HISTORICAL PERSPECTIVE
-Norman W Kigsley was the first to use the forward positioning
of the mandible.
-Pierre Robin first designed an appliance that was later used to
influence muscular activity by change in the spatial relationship of
jaws.
-Alfred P Rogers recognised the importance of orofacial system in
the problems of orthodontic treatment.
-Viaggo Anderson designed an appliance that fitted loosely in the
mouth and transferred muscular stimuli to the jaws ;teeth
;;supporting structures. www.indiandentalacademy.com

-In 1909 Emil Herbst presented a fixed bite jumping device called
Sharnier or JOINT.
IN 1977 Pancherz resorrected the HERBST appliance for use as an
experimental tool in clinical research.
In 1979 Pancherz in ajo called attention to the possibility for
stimulation of mandibular growth by means of Herbst appliance.
Since 1979 the Herbst appliance has gained increasing attention
especially in europe and U.S.A’.

HERBST appliance is a fixed bite jumping appliance.Bite jumping can
be defined as a change in sagittal intermaxillary dental arch
relationships by an anterior displacement of the mandible.
The appliance is reported to produce both skeletal and dental
changes in growing individuals.
Appliance is compromised of telescopic mechanism with sliding pin
and tube components which keep the mandible in protruded
position.
Diagnostic criteria for case selection
Growing patients with skeletal class-2 and dental class div-1 and
2 malocclusions. www.indiandentalacademy.com

-Patients with retrognathic mandible & orthognathic maxilla with
ANB OF 5 or greater.
-Positive V.T.O.
-WELL aligned maxillary and mandibular dental arches.
-Favourably Y- axis .
-Normal nasiolabial angle.
-3mm or greater Witts appraisal.
-upper incisor angulation to SN plane of 104 or greater.
-lower incisal to mandibular plane of 95 or lesser.

INDICATIONS
-Growing patients with skeletal and dental class-2 div 1&2
malocclusions.
-patients with orthognathic maxilla and retrognathic mandible.
-patients who have passed the pubertal growth spurt but still have
some growth potential left in them.
-in patients with mouth breathing habit.
-uncoperative patients
CONTRAINDICATIONS

-Hyper divergent facial patterns.
-abnormal mid face.
-negative V.T.O.
DESIGN OF THE APPLIANCE
It is a bilateral telescopic mechanism attached to orthodontic bands
and keeps the mandible in an advanced position.Telescopic device
consists of
-TUBE; -PLUNGER; -TWO PIVOTS; -TWO LOCKING SCREWS.
Pivot for the tube is attached tomaxillary first molar bands and pivot
for plunger is attached to mandibular 1st
pre molar band. Length ofwww.indiandentalacademy.com

Length of the plunger should be kept at maximum to prevent it from
disengaging from tube on wide mouth opening.
The mechanism permits vertical opening movements and also lateral
movements of the jaw.
ANCHORAGE SYSTEM OF THE HERBST APPLIANCE
Conventionally in the maxillary arch the 1st
premolars and permanent 1st
molars are interconnected on each side with half round or
roundsectional wire. In mandibular arch the 1st
premolar bands are
connected with a round lingual wire that touches the lingual surfaces
of front teeth.THIS FORM OF ANCHORAGE IS CALLED PARTIAL ANCHORAGE.
In some instances this type of anchorage is insufficient and there forewww.indiandentalacademy.com

In the maxillary arch labial sectional wire is placed in the brackets of
premolars,canines,incisors.In the mandibular arch lingual sectional
wire is extended to 1st
permanent molars which are banded.This form
of anchorage is called TOTAL ANCHORAGE.
In the deciduous and mixed dentition period bonded type of herbst is
used because of absense of 1st
premolars.This system is called SPLINT
ANCHORAGE SYSTEM.
PELOTT ANCHORAGE system: in the mandibular arch with the lingual
arch wires acrylic pelott is fabricated and fixed touching the lingual
mucosa about 3mm below the gingival margin.
This system is most efficient in withstanding the stresses plced on
lower anterior teeth. www.indiandentalacademy.com

CONSTRUCTION OF THE APPLIANCE
THE CONSTRUCTION BITE: Bite is recorded by motivating the patient to
posture mandible forward in an edge to edge incisal position with
midlines coinciding.If acrylic splints are needed care should be taken
that sufficient vertical clearence is left for their construction.
After the bite registration models are mounted on an articulator with
the wax bite.
CONSTRUCTION OF BONDED HERBST:All bands except those on the
mandibular 1st
molars should be formed of band material of 0.15mm
thickness
-construction bite is taken with mandible advanced to desired positionwww.indiandentalacademy.com

And alginate impressions are made while bands are still on teeth.
Bands are fixed in the impression and plaster models are poured .The
banded models are oriented to each other in the construction bite and
mounted in an articulator.Lingual arch wires and pivots for the
telescopic mechanismare soldered to the bands.
The finished appliance is cemented and telescopic mechanism is
attached to the pivots using a screw driver .
CONSTRUCTION OF BANDED HERBST:Acrylic splint herbst consists of a
wire frame work over which 2.5-3.0mm of biocryl is pressure moulded
using biostar .Posterior teeth are covered from canines through 1st
molars in the upper arch.Whereas full occlusal coverage is provided
for the mandibular arch. www.indiandentalacademy.com

MAXILLARY WIRE FRAME WORK:Alength of 0.045 elgilloy wire is bent
around the premolars and molars both on buccal and lingual side and
transpalatal bar is included in the design to increase stability.
MANDIBULAR WIRE FRAME WORK:0.40 INCCH ELGILLOY WIRE IS
CONTOURED ALONG the buccal, lingual surfaces of six anterior teeth
and posterior teeth.
Both wire frame works are placed on their work models and secured.
The pivots are oriented in correct horizontal ,vertical ,angular
positions and then welded.after the skeletal wire frame work is ready
biocryl sheet is adapted using biostar pressure moulding device.
The splint is cemented with light cure resin system.

TREATMENT EFFECTS
EFFECTS ON DENTOFACIAL COMPLEX: Herbst appliance is the most
powerful treatment modality in the treatment of class-2
malocclusions.
-normalization of oclusion is accomplished in 6-8 months of
treatment.Overcorrected sagittal dental arch relations & incomplete
cuspal interdigitation are expected at end of treatment.
Improvement in sagittal & dental arch relations are result of both
skeletal dental changes.
Overjet was reduced by an average of 7mm &molar relationship
improved by 6.5mm during treatment period.www.indiandentalacademy.com

During the 1st
post treatment period of 6 months the overjet
relapsed by 2mm &molar relation by 1.6mm. These occlusal changes
were result of maxillary &mandibular tooth movements.
Maxillary&mandibular growth were equal and did not contribute to
the occlusal changes observed.
-DURING 2ND
POST treatment period of 6 months overjet recovered
by .3mm while molar relation was almost unchanged. Maxillary
&mandibular tooth movements were minimal .Mandibular growth
was .2mm larger than maxillary growth & this counteracted
negative effects of dental changes.
EFFECTS ON MANDIBLE : In order to examine the short term & long
term effects of herbst treatment on mandibular growth &www.indiandentalacademy.com

Mandibular morpholgy was assesed by measuring the jaw base
length (C-PG) & GONIAL ANGLE & beta angle.
During 6 months of treatment mancibular base length increased
more in the Herbst group ,gonial angle opened & beta angle closed
in the herbst group.
At the end of growth the increase in mandibular base length was
less than that in the control group. Gonial angle closed more in
herbst group ,beta angle opened more in the herbst group.
MARKED mandibular morpholgical changes occurred during herbst
treatment.After treatment these changes seemed to revert and on
a long term basis no influence of herbst on mandibular morphology
could be verified. www.indiandentalacademy.com

EFFECTS ON MAXILLA :
1.Sagittal maxillary jaw position changes: During the total
observation period average amount of forward growth of maxilla
was 3.6mm which was about half the forward growth in control
group.Hence the appliance has a significant restraining effect on
the growth of maxilla.
2. Palatal plane changes: During the total observation period
palatal plane tipped downward by 1.1 degrees which was twice
that seen in untreated controls.
3. Occlusal plane changes: On average occlusal plane tipped upward
by .6mm during the total observation period which was half that
seen in controls. www.indiandentalacademy.com

4. Sagittal maxillary molar position changes: During the total
observation period the molar moved mesially by .6mm which was
60% that seen in untreated controls.
5. Vertical maxillary molar position changes: During the observation
period molars intruded by 3.9mm which was comparable to that
seen in controls.
Conclusion was the appliance had marked high pull head gear
effect on maxillary complex.
Herbst appliance : 1. Stimulates mandibular growth
2. Inhibition of maxillary growth.
3.distal movement of upper teeth .4.Mesial movement of lowerwww.indiandentalacademy.com

EFFECTS ON FACIAL PROFILE: Herbst appliance treatment results in
reduction of hard &soft tissue profile .upper lip becomes retrusive
& whereas lower lip remains unchanged.
EFFECTS ON MASTICATORY SYSYEM:
-Patients adapt to appliance &accept it quikly despite the fact
that at the beginning of treatment they have contact between
anterior teeth .Chewing difficulties are experienced only during 1st
7-10 days of treatment .
-No adverse long term effects of appliance on craniomandibular
system have been found during examination at end of their
growth period .
Treatment with herbst appliance normalizes EMG pattern of

Temporal &masseter muscles .
Lateral tomograms of patients treated with herbst appliance have
noted normal condyle - fossa relation ,however research
indicates anterior positioning of articular fossa.TMJ remodelling
ocurred with bony apposition at inferior border of anterior
aspect of postglenoid fossa ,and at posterosuperior aspect of
condyle.
MULTI PHASE TREATMENT APPROACH:
1. Treatment of class 2 div-1 malocclusion :
a. Orthopaedic phase b . Orthodontic phase
2 .TREATMENT OF CLASS 2 DIV –2:www.indiandentalacademy.com

TIMING OF TREATMENT :
Favourable time to start treatment is at peak of pubertal
growth spurt .
Pancherz recomendslate appliance therapy just after the peak of
growth velocity to favour occlusal stability after treatment and
to reduce post treatment retention .
Early treatment is not recommended because stable cuspal
interdigitation is difficult after appliance therapy and this
prolongs retention period after appliance removal .

RETENTION & RELAPSE
Good post treatment occlusal intercuspation has been emphasized
for the prevention of skeletal & dental relapse.
Pancherz list of relapse promoting factors :
1. EARLY or MIXED DENTITION TREATMENT
2. ATYPICAL SWALLOWING HABITS .
3. RECOVERY GROWTH CHANGES AFTER TREATMENT.
Treatmemt generally leads to over corrected sagittal dental arch
relations with incomplete cuspal interdigitation .Thus a period
of active retention is necessary with andreson activatoruntil
the occlusion has settled into good intercuspation .

MODIFICATION IN HERBST APPLIANCE TREATMENT :
In class –2 cases with narrow ,constricted maxillary arch
expansion can be performed with herbst appliance by soldering
quad helix or other rapid palatal expansion devices to the molar
& premolar bands.
If mandibular 1st
premolars have not erupted permanent can be
used for anchorage .
Buccal tubes can be welded to mandibular molar bands for
addition of franckel type lip pads which is usefull for correction
of hyperactive mentalis muscle activity or alipbumper may be
added to the buccal tubes to provide distalizing force to the
mandibular dental arch. www.indiandentalacademy.com

Raymond weislander suggested the use of vertical pull chin cap
or high pull head gear in case of patients with vertical
hyperplasia of lower face along with herbst appliance .
TAREK ZREIK ( JCO –1995) has modified the appliance to decrease
the breakage problems with banded herbst appliance & called it
as EMDEN modification .It includes :
a. stainless steel crowns on maxillary 1st
permanent molars.
b. removable acrylic splint on mandibular arch .
C .double buccal tubes on stainless steel crowns of upper 1st
permanent molars which can accommodate utility arches ,sectional
or continuous wires.

Screws protrude enough to encroach upon mucosa of cheek &
cause ulceration,to solve this problem HUG –CAPS are marketed
which can cover screws .
Sandblasting the underside of band or crown with microetcher
increases the retention of appliance .
American orthodontics has come out with photoetched bands with
increased surface area . Photoetched bands with glass ionomer
cement make loose bands a distant memory .

FLIP LOCK HERBST
Flip-Lock Herbst appliance's ball-joint
connector. End of rod crimped onto mandibular
ball.
Split bushings used for
reactivation. Split bushings used for reactivation.www.indiandentalacademy.com

Cantilever Herbst design.
Buccal cantilever wire made by doubling .045"
wire and soldering the two strands together.
Mandibular acrylic matrix Herbst design.
Atlas Axle with tube and piston hela togetner
by cotter pin.www.indiandentalacademy.com

Herbst appliance with hexagonal screws.
. Maxillary Malu attachment with cotter pin
opening. B. Mandibular Malu attachment with
archwire slot and cotter pin opening.
Assembled Herbst with Malu attachments.

. Sliding auxiliary archwire, made of .9-1mm round stainless steel, inserted
in lower first molar tube. B. Force of Herbst appliance distributed to main
mandibular archwire by auxiliary archwire.
Auxiliary archwire attached anteriorly to main archwire with
elastomeric modules. B. Posted mandibular archwire.

Different hooks of .9-1mm stainless steel wire used to attach Herbst tubes
to upper first molar bands, depending on space available between upper and
lower first molars.
Malu attachment, combined with stopped wire, used to attach
Herbst tube to upper first molar band.

. In skeletal open bite case, upper second molar is banded and Herbst tube is attached as far
distally as possible. This increases distance from assumed center of resistance of maxillary
dentition (CR ud) to attachment point of Herbst tube, increasing length of moment arm of
intrusive force from Herbst appliance. B. Placing tube too far distally can cause interference
with masseter muscle (pars superficialis).

. Coelho design, using 1.5mm-diameter rod attached to upper first molar and
sliding freely along auxiliary archwire. B. Tube added to auxiliary archwire
distal to stop in lower canine area to increase mandibular advancement.

Removable Plastic Herbst retainer, with upper and lower occlusal splints
connected by the herbst mechanism.

Components of Mandibular Advancement
Locking Unit (MALU).
Upper "Mobee" hinge inserted into hole on
tube and secured to headgear tube with ball
pin.
Lower key hinge inserted into hole on plunger
and locked to base arch with brass pin.
With upper and lower MALU components in place, len
of tube-plunger assembly is adjusted according to
desired mandibular protrusion.www.indiandentalacademy.com

CONCLUSIONS
If your only instrument is hammer than every problem
looks like anail. Similarly if only orthodontic tool for
treating class-2 malocclusions is a retractor then every
class-2 will seem like amaxillary protrusion and clearly
not every one is.
Herbst appliance is not a theraupeutic panacea but
when diagnosis and patient selection are accurate it can
routinly treat difficult non co-operative class –2
patients successfully.www.indiandentalacademy.com

Herbst appliance & its modifications

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Herbst appliance & its modifications