Headgears

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WHERE YOU ARE GOING;
YOU’LL PROBABLY
END UP SOMEWHERE ELSE”
because ……www.indiandentalacademy.com

• The eyes don’t see what the mind
doesn’t know
- anonymous
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Geared-upGeared-up
OrthodonticsOrthodontics
Use of HG in day toUse of HG in day towww.indiandentalacademy.com

Prof. K.SADASHIVA SHETTYProf. K.SADASHIVA SHETTY
Dean & HOD
Department of Orthodontics
and Dentofacial Orthopedics
Bapuji Dental College & Hospital
Davangere
INDIA

bdch@satyam.net.in

• History
• Classification
• Components
• Biomechanics
– Direction
– Magnitude
– Duration
• Clinical points
– Bending of Inner bow
– Bending of Outer bow
• Practical management
• Uses
– For the orthodontics
purpose (with fixed
appliance)
• Anchorage
reinforcement
• Distal movement
• Molar rotation
– For orthopaedic purpose
(with removable/fixed
appliances)
• Splint Headgear
• Activator headgear
• Patient motivation
• Warning and safety

HistoryHistory
Changing views of treatment with
extra-oral anchorage

Traditional use of Extra Oral Force

Chinese Foot

JOSEPH FOX
• The chin cup was first used by Cellier in 1802
& a year later by Fox ( not for anchorage but
for luxation cases).

Late 18 century
Norman Kingsley (1829 - 1913)
““Father of Orthodontics”Father of Orthodontics”www.indiandentalacademy.com

Norman Williams Kingsley
• Although Westcott & others had previously
used the Head-cap for occipital anchorage,
Kingsley, 20 years later, reintroduced this
method, & for 40 years it proved the only
successful method of handling extreme cases
of malocclusion.

• He also made use of the Head-cap to
shorten teeth by retracting them within
the jaw after they had elongated through
“natural or developmental causes”.

Edward Hartley Angle
““Founder of Modern ScientificFounder of Modern Scientific
Orthodontia”Orthodontia”

Angle used astonishingly modern appearing
appliances, apparently with reasonable success.

Class II elastics
• Class II elastics was introduced by Angle
and was very popular among his
students.

• Angle and his followers were convinced
that class II and class III elastics not only
moved teeth but also caused significant
skeletal changes, stimulating the growth
of one jaw while restraining the other.

Cephalometrics
• Invention of X-rays  cepahlometrics
• Superimposition of cephalograms of
Class II elastics showed adverse tooth
movements.
• Therefore, in 1940’s HG were
reintroduced as tooth moving devices.

Orthopedic appliance
• Late 1950’s lateral cephalograms
demonstrated restrained effects on
maxillary growth.
• However, there was resistance by
Americans who believed that it was
mandibular growth which was
responsible for success of HG.

Kloehn HG Vs Other HG
• Till then only cervical HG was commonly
used (Kloehn HG).
• Then the Americans used Combi and
High pull HG to achieve success even
with a not so good growing mandible.

ClassificationClassification
of Head-gearsof Head-gears
Headgear appliances are often
described by their relationship
to the occlusal plane :
•Above the Occlusal plane = high pull
•In line with Occlusal plane = combi-pull
•Below the Occlusal plane = low pullwww.indiandentalacademy.com

High Pull Head-gear

Combi-Pull Head-gear

Low Pull Head-gear

ComponentsComponents1. Molar tube
2. Face bow
3. Force module
4. Head strap

Components of Head-gear assembly
•Molar tube
•Face-bow
-Inner bow
- Outer bow
•Force module
•Head strap

Molar Tube:
0.045 inch
0.045 inch
Fixed appliance Removable appliance

Facebows – types:
1. Inner-outer bow type
2. J-hook type
Soldered
joint
Outer bow
Inner bow

Inner-outer bow type
• Commonly used with fixed or
functional/removable appliance.
• Inner bow is available in either:
– 0.045 inch
– 0.051 inch
• Outer bow diameter is :
– 0.072 inch

J-hook type
• An alternative method
of applying extra-oral
forces to a fixed
appliance.
• The hooks are termed
‘J’ hook on account of
their shape and are
attached directly to the
arch wire usually in the
incisor region.

131211
• Each J-hook consists of a 0.072 inch
wire contoured so as to fit over a small
soldered stop on the arch wire.
1 3 1 2 1 1

Force Modules
Light force moduleHeavy force module

Head strap
Neck strapNeck strap
Used for cervical pull headgearUsed for cervical pull headgear

BiomechanicsBiomechanics
1. Direction
2. Magnitude
3. Duration

Force (The only prescription in orthodontics)
• Since force is the treatment agent, it is
imperative to master the fundamentals of
biomechanics.
• The design of the force system
predetermines the general direction in
which
– the tooth,
– group of teeth, or
– skeletal unit
responds. www.indiandentalacademy.com

• The quantity of force can be controlled
rather well.
• However, exact prediction of the tissue
response and the growth behavior in an
individual case is highly speculative.
• It is therefore mandatory to monitor the
mechanics according to the reactions
observed at each treatment visit.

Center of Resistance
• Applying a force through
the center of resistance
will lead to a pure
translatory movement
along the force vector.
• Unless the force direction
is parallel with the
occlusal plane, tooth will
also move vertically
(intrusion & extrusion).

• Applying a force away
from the center of
resistance will lead to a
combination of translatory
and rotational movement.
• The amount of rotational
effect will depend on the
distance of the force
vector at right angle from
the center of resistance.

• The relative amounts of
angular change and
translation are determined
by the length of the
shortest distance between
the line of force and the
center of resistance.

• Since the kind of reaction to an applied
force system is so strongly dependent
on the site of the center of resistance, it
is of paramount importance to estimate
where its location will be.

It is Postulated that …
• The nasomaxillary complex, suspended
as it is by a sutural system comparable
to the desmodermal system of a tooth,
therefore possess a center of resistance.

Some of naso-maxillary complex sutures
• Zygomatico-frontal
• Fronto-maxillary
• Naso-maxillary
• Zygomatico-maxillary
• Zygomatico-temporal
• Palato-maxillary

• A force vector would
have to pass through
of the dentition and
through the center of
resistance of the
maxilla if no rotational
effects are to be
induced.

• According to observed
clinical reactions the
location of the center
of resistance of the
maxillary complex
must be somewhere in
the area of the
postero-superiorpostero-superior
aspect of theaspect of the
zygomatico-maxillaryzygomatico-maxillary
suture.suture.

A word of caution:-
• The location of the center of resistance of a
biologic entity cannot be exactly determined in
advance and furthermore is subject to
alteration by tissue and other factors.

Cervical Anchorage
with low-pull Headgear
Anti-clockwise
Rotation
Clockwise
Rotation
Translation

Occipital Anchorage
with combi-pull Headgear
Anti-clockwise
Rotation
Clockwise
Rotation
Translation

Parietal Anchorage
with high-pull Headgear
Anti-clockwise
Rotation
Clockwise
Rotation
Translation

Direction of force application is further
affected by:
1. Length of outer-bow of the facebow.
2. Angulation of the outer-bow relative to
the inner-bow, in the horizontal plane.

• Rather than considering in detail all
possible combinations of variables, it is
best to understand only a few.
• The essential issue is the relationship
between the direction of the extra-oral
force and the center of resistance of the
unit to be moved.

Varying Outer Bow Length

Magnitude of ForceMagnitude of Force

Magnitude of Force
• Distalization:
– For canine retraction
– For molar distalization
– For posterior teeth distalization
– For full arch distalization
• Anchorage:
– For anchorage of molar tooth during retraction
– For anchorage of full arch against Class III elastics
• Orthopaedic purpose
– along with fixed appliance (rigid wire consolidation)
– along with splint/activator appliance

Non – growingNon – growing
patientspatients
Role of headgear in
orthodontic correction

Control on inter-molar width with
Transpalatal Arch (TPA)

Use of headgear for retraction of molar and premolars

For the expansion of upper arch

CASE REPORT

•Unilateral
Distalization

PRETREATMENT

PRE TREATMENT

UPPER 014 NITI
UPPER ANTERIOR
BITE PLANE

UPPER 014 SS

UPPER 016 X 022SS LOWER 016 SS

UPPER 017 X 025 SS LOWER 016 X 022 WITH
CERVICAL PULL HEADGEAR

UPPER /LOWER 017 X 025 SS

UPPER 016 X022 BRAIDED ARCHWIRE
LOWER 016 SSwww.indiandentalacademy.com

POST TREATMENT

GrowingGrowing
patientspatientsRole of Headgears in
Orthopaedic Correction
of Skeletal
Malocclusions

• The human facial form is determined
largely by the relative positioning of the
maxilla and mandible before, during and
after pubertal growth spurtpubertal growth spurt.

• The harmonious positioning of the
maxilla and mandible relative to the
cranium not only facilitate the ultimate
function of the jaw and teeth to break up
food-mastication (Proffit et al., 1993),
• but also forms the anatomical basis of
pleasing facial esthetics (Bishara & Jakobsen,
1985).

• For growing patients  we need to
understand and respect the relationship
between the displacement and rotation
trends of the different facial units.
• The movement of the mandibular
symphysis relative to the rest of face is
of paramount importance.

The vertical growth of the mandibular condyles
(CO) and descent of the glenoid fossae (GF)
balance
the vertical downward movement of the
maxilla (MA) and upper alveolar process (UA)
plus downward movement of the lower
alveolar process (LA).
CO + GF = MA + UA + LA

Average growth pattern
• with downward and forward displacement of
the mandibular symphysis (Gnathion) along
the Facial Axis
CO
GF MA
UA
LA

Normal Relation of Jaws to each-other & Cranium

• A dentofacial deformity is present if the
maxilla and mandible are out of
proportion to each other or to the rest of
the cranium (Enlow,1990; Proffit & White, 1990).
• Dentofacial deformities exist in the
maxilla and/or mandible in all threein all three
dimensions of spacedimensions of space.

Dentofacial deformities in relation to
maxilla:
• Maxillary excess
– Antero-posterior
– Vertical
– Transverse
• Maxillary deficiency
– Antero-posterior
– Vertical
– Transverse
• Maxillary rotation
– Forward rotation
– Backward rotation

Maxillary excess

Maxillary deficiency

• The optimal clinical approach for
correcting some of Class II and Class III
dentofacial deformities is to modify
maxillary growth during the adolescent
growth spurt …
• by means of appliances that exert
orthopaedic forces against the maxilla
and subsequently change the maxillary
form (Proffit & White, 1990; Proffit et al., 1993).

Lowering of palatal plane
Supra-eruption of
Dentition
Problem: Maxillary excess in A.P. &Maxillary excess in A.P. &
Vert ical planeVert ical plane

Treatment: Rest raining of t he Naso-Rest raining of t he Naso-
Maxillary complexMaxillary complexCenter of resistance
of Maxilla
Center of resistance
of Dentition

Excess vertical growth of maxilla

Pre-expansion Post-expansion

• There are lots of information on
evaluation of the maxillary shape,
position and its relation to the other
structures of the face.
• However, maxillary rotation in relation to
the dentofacial complex was more or
less ignored.

Maxillary Rotations
• The rotation of jaws are an important
factor to be considered while planning
treatment for any patient.
• Until the implant studies were done,
rotations of the maxilla during normal
growth had not been suspected.

Components of Maxillary rotation:
1. Internal rotation of the maxilla.
2. Resorption of bone on the nasal side
and apposition of bone on the palatal
side in the anterior and posterior parts
of the palate.
3. Similarly, there are variations in the
amount of eruption of the incisors and
molars.

Maxillary growth rotations

Anterior Vertical Excess
Anteriorly
Normal eruption of
Dentition

Posterior Vertical Excess
Posteriorly
Normal eruption of
Dentition

Normal downward and
forward growth of Maxilla
Supra-eruption of upper
anteriors Teeth

Normal downward and
forward growth of Maxilla
Supra-eruption of upper
posterior Teeth

Cervical Pull Headgear
When the inner bow and outer-bows are in the same
plane there is a clockwise rotation of both maxilla
and maxillary dentition.
ADD PICTURES FROM pea 2002 DAY-2

Cervical Pull Headgear
• If the outer-bow is bent upwards so
that the direction of traction is between
the centres of resistance of maxilla and
maxillary dentition, the maxilla will rotate
in a clockwise direction and the
dentition will rotate in an anticlockwise
direction.

Combi Pull
• The outer bow is angled at 15 degrees.
• The force passes through centre of
resistance of dentition.
• For more distalization of molar with
minimal rotational effect.

Ideal Line of Action of Force
• When the pull passes through
centres of resistance of both the
maxilla and maxillary dentition,
vertical and rotational control is the
best.

Ideal Line of Action of Force

Force Passing Through Center Of
Resistance

Problems associated with adjusting the direction
of force ………

Solution….…“we do it this way”

ACTIVATOR HEADGEAR

• In Class II div I malocclusion, later followed
by fixed mechanotherapy for fine tuning.
• In Class II div II malocclusion, but prior to
this the central incisor have to be proclined
with removable appliance.
• During treatment with fixed appliances, the
activator headgear can be used
simultaneously.
INDICATIONS

• On completion of treatment with fixed
appliances, in some cases the slide in centric
is still too long, or the resulting profile is
unsatisfactory.
• In such cases a combined activator-
headgear appliance can be given to bring
about further anterior development of the
mandible.
INDICATIONS

• Dento alveolar effect on the maxillary
dentition is in a posterosuperior direction.
• Inhibitory effect on the maxilla is counter to its
downward and forward direction of
development.
• Effect on the mandibular dentition is in the
mesial direction.
• Deblocking of the occlusion during treatment.
MODE OF ACTION

• Stimulation of condylar growth, combined
with temporary posterior deflection of
condylar growth direction.
• The construction bite prevents the maxillary
dentition from influencing the position of the
mandible at the same time keeping it in a
forward position.

Activator Headgear
• Bite construction is registered by protrusive
mandibular bite not exceeding 6mm and vertical
dimensions is opened to maximum of 4mm, just
making possible the placement of headgear tubes .placement of headgear tubes .

Activator Headgear

PRE-RX AGE 13 YEARS

POST ORTHOPEDIC AGE 14 YRS

Reverse-pull HeadgearReverse-pull Headgear
(Face mask)(Face mask)
For the treatment of maxillary
deficiencies (horizontal and vertical) in
Class III malocclusion cases.

• Up to now, bilateral elastic protraction
forces were applied to the dentition in an
effort to alter developing Class III
malocclusions.
• Their line of action and points of
attachment were essentially dictated by
the commissure of the lips.

Reduced lowering of
palatal plane
Problem: Maxillary def iciency in A.P.Maxillary def iciency in A.P.
& Vert ical plane& Vert ical plane
Over closing of the
Manible

Treatment: Rest raining of t he Naso-Rest raining of t he Naso-
Maxillary complexMaxillary complexCenter of resistance
of Maxilla
Rotation of the
Manible
Downwards and
Backwards

Ideal force direction for Maxillary Deficiency
• A force vector would
have to pass through
of the dentition and
maxilla ifmaxilla if no rotationalno rotational
effectseffects are to be
induced.
• But with conventional
techniques the force
vector was dictated bydictated by
the commisure of thethe commisure of the
lips.lips.

• This produces an
equivalent protraction
force accompanied by
an undesirable counter-undesirable counter-
clockwise momentclockwise moment at
the center of resistance.
• This is undesirable
because it results in
mandibular rotation and
increased lower facial
height.

• Since Class III mal-
occlusions are generally
not characterized by
deep overbites,deep overbites, and
because mandibular
rotation will provide a
pseudo correction of thepseudo correction of the
Class III relationship,Class III relationship, the
value of this protraction
force system is some-
times questionable.

Recent modification
• A standard facebow may be contoured to
insert in the maxillary molar tube from the
distal end.
• Then the outer bow is adjusted so that the line
of action of the protraction forces is controlled.

Chin-CupChin-Cup
For the treatment of mandibular
excess (horizontal and vertical) in
Class III malocclusion cases.

• Controversies exist regarding its
advantages.
• Even though it might redirect the growth
of the mandible at early stages, what
about the late mandibular growth.
• High frequency of relapse, therefore not
used in our department.

• However a differentiation needs to be
made between True Class IIITrue Class III and a
Pseudo Class IIIPseudo Class III
• Pseudo Class III is due to anterior shiftanterior shift
of the mandibleof the mandible and often associated
with missing posterior teeth.

• True Class III and especially those
associated with vertical growth patternvertical growth pattern
should be treated once the growth is
completed by means of surgicalsurgical
orthodontics.orthodontics.

a) The forces passing through the condyles
b) The forces passing below the condyles
a bwww.indiandentalacademy.com

a) The face grows but the chin is restrained
b) The chin grows downwards and backwards
a bwww.indiandentalacademy.com

Patient MotivationPatient Motivation

Controlling Factors
• The effectiveness of HG therapy is
influenced by factors controlled by the
orthodontist, such as :
– Direction & Magnitude of HG force
• And by factors that are largely under the
control of the patient, such as:
– Duration of HG wear or patient compliance.

• High degree of co-operation on the part of the
patient is a must.
• Best to fit the headgear at the commencement
of the treatment, because it is difficult to
increase the patient’s motivation part way
through treatment.
• Motivation can often be maintained with the
use of charts which the patient completes to
record the time the appliance is worn each
day.

Warning and SafetyWarning and Safety

Inform both, the patient and his/her parents :-
1. Hold the bow in the mouth while the traction
force is engaged or disengaged.
2. Immediately hold and restrain the bow if it
becomes loose.
3. No vigorous activity when wearing the
headgear.
4. Never wear the headgear without the safety
device being in place.
5. Report any damage or breakage of the
appliance as soon as possible.
6. Stop wearing the headgear, and contact the
orthodontist if the bow comes out at night.www.indiandentalacademy.com

Concluwww.indiandentalacademy.com

• Force is a potent weapon in the hands of
an orthodontist.
• How he makes use of that weapon
determines the relative success or
failure of the orthodontist.

• As with any kind of weapon, force has its
own good and bad effects.
• Ultimately the success of therapy
depends on the usage of right kind of
weapon for the right kind of battle.

Construction ofConstruction of
Splint headgearSplint headgear
AnimationAnimation

Fitted labial bow and Adams on cast

Occlusal view of splint with face bow

Splint headgear
• Headgear tubes are
embedded in the
acrylic between the
first molar and
second premolars .
• The acrylic splint
should be made
evenly to contact all
the lower teeth , to
prevent any supra-
eruption .

Headgears

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