The headgear /certified fixed orthodontic courses by Indian dental academy

THE HEADGEAR
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


CONTENTS

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INTRODUCTION
HISTORY
TYPES OF HEADGEAR
USES OF HEADGEAR
HEADGEAR ASSEMBLY
SELECTION OF CASES
CLINICAL PROCEDURES
BIOMECHANICS & FORCE PRESCRIPTION
HEAD GEARS IN COMBINATION THERAPY
CONCLUSION

HISTORY

Kingsley – late 1800’s


HISTORY

Ball joint

Angle’s E- arch appliance, Early-1900’s

EFFECT OF CLASS II ELASTICS


HISTORY

Silas Kloehn, after World War II


PRESENT DAY


HEADGEAR ASSEMBLY
Head

cap
Cervical strap
Face bow components
 Outer

bow (.051” or .062”)
 Inner bow (.045” or .052”)

Molar

bands and headgear tubes
Force element

HEAD CAP


NECK STRAP


MOLAR BAND


MOLAR TUBE -OCCLUSAL


MOLAR TUBE GINGIVAL


TRACTION RELEASE FORCE
MODULES


TYPE OF OUTER BOW


FACE BOW JUNCTIONS (Dougherty and
Beazley AJO, Nov 1976)

Brazed / soldered joints


FACE BOW JUNCTIONS

Parallel pin-and-tube
attachment


FACE BOW JUNCTIONS

Tongue- and-groove
attachment


FACE BOW JUNCTIONS

Key-and-slot
design


MODE OF ATTACHMENT TO
DENTITION


Headgear tubes on 1st molars



Maxillary splint



Functional appliance



J- hooks attached to archwire


INDICATIONS
 Growing

individuals
 Class II Div 1 malocclusion


TYPES OF HEADGEAR
 Occipital

/ High pull head gear
 Cervical / Low pull head gear
 Vertical pull headgear
 Combined Occipital & Cervical / Straight pull
headgear
 Interlandi / Variable pull headgear


KLOHEN FACEBOW


RAMPTON FACE BOW


ROOT HIGH PULL FACE BOW


Occipital / High pull headgear


Cervical / Low pull Headgear


Combination / Straight pull


Vertical pull headgear


Interlandi / Variable pull headgear


HIGH PULL HEADGEAR WITH J HOOK

J

HORIZONTAL PULL HEADGEAR


 PROTACTION

HEAD GEAR
 REVERSE PULL HEAD GEAR- FOR
TREATMENT OF CLASS III


ASSYMETRIC HEAD GEAR


TYPES OF FACE BOWS (Hershey,
AJO-DO Mar 1981)
 Bilaterally

symmetrical face bow
 Power-arm unilateral face bow
 Soldered offset or fixed union unilateral face
bow
 Swivel offset or swivel union unilateral face
bow
 Spring attachment unilateral face bow

BILATERALLY SYMMETRICAL
FACE BOW


POWER-ARM UNILATERAL FACE
BOW


SOLDERED OFFSET OR FIXED
UNION UNILATERAL FACE BOW


SWIVEL OFFSET OR SWIVEL UNION
UNILATERAL FACE BOW


SPRING ATTACHMENT UNILATERAL
FACE BOW


USES OF HEADGEAR
Growth

modification
Anchorage augmentation
Space maintenance
Molar distalization


APPLICATIONS OF HEADGEAR
 ORTHOPAEDIC

Restriction of maxilla
 Distalization of maxilla
 Intrusion of maxilla



GROWTH MODIFICATION
 TREATMENT

OF CLASS II

 RANDOMISED

CLINICAL TRIALS OF 1990s
DATA Shows that functional appliance and
headgear both shows small but significant
improvement in jaw relationship than controls
Similar decrease in ANB

 IN

Case of 2 phase treatment headgear is
compatible with fixed appliance


SHORT FACE (SKELETAL DEEP BITE )
CLASS II
 The

additional goals are
-block eruption of incisor teeth
-control eruption of upper posterior teeth
-facilitate eruption of lower posterior teeth

This pattern of change is produced most
effectively with a functional appliance


 Cervical

headgear are used in deep bite
cases ,it differentially allow eruption of upper
first molar rather than lower
 Activator and bionator are useful in such
type of cases
 Fixed functional appliance of the Herbst type
tend to depress upper molars ,usually they
are not recommended for short face patients

Class II CHILDEREN WITH NORMAL
FACE HIEGHT
 Either

headgear or any type of functional
appliance is acceptable

 Straight

pull or high pull headgear is
preffered over cervical headgear ,to reduce
elongation of maxillary molars and better
control of mandibular plane


 Functional

appliance that minimize tooth
movement are preffered to obtain maximum
skeletal effect


Long face (skeletal open bite class II)
 Major
-

diagonostic criteria
Short ramus
Rotation of the palatal plane up posteriorly
Excessive maxillary posterior growth than
anteriorly
Downward and backward rotation of
mandible
Excessive eruption of maxillary and
mandibular teeth

 Keys

to successful growth modification would
be restraining vertical development and
encouraging anterioposterior mandibular
growth,while controlling eruption of teeth in
both jaw


HIERECHERY OF EFFECTIVENESS IN
LONG FACE CLASS II TREATMENT
 HP

headgear to functional bite blocks

 Bite

blocks on functional appliance

 High

pull headgear to maxillary splint

 High

pull headgear to molars

HIGHPULL TO
M.I.S

EFFECT ON MAXILLA
 It

should be worn 12-14 hrs day
 Current recommendation of force -12-16
ounce side (350-450gm side day


Force prescription
 Force

of 500 -1000 gm total
 Force direction slightly above the occlusal p
lane –through the centre of resistance of
molar teeth
 Force duration – at least 12 hours from early
evening until next morning
 Typical treatment duration -12 -18 months

Correction of molar relationship
 To

change end –to – end molar relation to
class I
 More the child wear the headgear is better
 14- 16 hrs day
 100 gm side
 Tooth movement 1mm month
 3 mm movement in 3 months

For anchorage reinforcement
 Ratio

of pdl between anchorage unit and
tooth moving unit is
2:1 without friction
4:1 with friction
Head gear apply backward force on upper arch
The reaction force is disspiated against the
bones of cranial vault
Problem
– intermittent force



ANCHORAGE AUGMENTATION (with intraoral
mechanics)

Closure of 1st
premolar Xn
space

By pass arch for levelling by intrusion
 High

pull headgear to the upper molars can
be added with any of bypass arch systems to
improve upper posterior anchorage


Canine retraction
 Avoid

strain on posterior teeth

 Disadvantage-

heavy and intermittent force
more friction may cause assymetric
response


 CAN

BE USED FOR DISTALIZATION OF
FIRST MOLAR AFTER SECOND MOLAR
EXTRACTION
 STRAIGHT PULL OR HIGH PULL
HEADGEAR IS INDICATED
 FORCE -300 gm side


Retention after class II MOLAR
CORRECTION
 OVER

CORRECTION OF OCCLUSAL
RELATIONSHIP
 CONTINUE NIGHT TIME WEAR OF
HEADGEAR WITH RETAINER
 USE OF ACTIVATOR – BIONATOR TYPE
OF FUNCTIONAL APPLIANCE


 TOOTH

MOVEMENTS
 Molar distalization
•
•

 Distal

Bilateral
Unilateral

molar crown tipping
 Distal molar root tipping
 Molar intrusion
 Canine retraction
 Retraction of maxillary anteriors
 Flattening occlusal plane

 SPACE

MAINTANENCE
 SPACE REGAINER


SELECTION OF CASES



3 major decisions
LOCATION OF THE HEADGEAR


FORCE PRESCRIPTION
 RESTRICTION





OF MAXILLA
250-500 grams/side
Worn atleast 12 hrs/day
Early in the evening till next morning
12-18 monthsdepending on growth and
patient compliance


 END





TO END MOLARS -> CLASS I
100 grams/side
Moderate intensity, longer duration
14-16 hrs/day
1 mm movement/month


 FIRST



MOLAR DITALIZATION FOLLOWING

7 Xn
300 grams/side
Full time wear


 CANINE


RETRACTION
200 grams/side


Longer bow bent up or short
outer bow bent down will
produce same line of action

HIGH PULL


CERVICAL PULL


COMBI-PULL


CLINICAL PROCEDURES






MOLAR BANDING
WITH TUBES
PREFORMED FACE
BOWS WITH
ADJUSTMENT LOOPS
IN INNER BOW
CHECK THE SIZE
USING PRE Rx CAST


CLINICAL PROCEDURES




PLACE IT INTO ONE
TUBE AND EXAMINE
ITS RELATION TO
THE OTHER TUBE
KEEP IT 3-4 mm
AWAY FROM THE
TEETH


CLINICAL PROCEDURES







INNER BOW MUST BE
PASSIVE IN THE MOLAR
TUBE
END SHOULD BE FLUSH
WITH TUBE OR NOT
MORE THAN 1 mm
Jn OF I.B. & O.B. MUST
PASSIVELY REST
BETWEEN THE LIPS






AS MANDIBULAR
ADVANCEMENT
TAKES PLACE THE
I.B. SHOULD BE
EXPANDED
EXPANSION OF 2MM






O.B. SHOULD BE
KEPT AWAY FROM
CHEEKS
CUT TO PROPER
LENGTH AND HOOKS
FORMED


 SELECTION

OF HEADCAP AND/OR
NECKSTRAP
 LOW FORCE LEVELS TO START WITH
 RECHECK BOW POSITION
 MAKE CHILD MANIPULATE UNDER
SUPERVISION
 PATIENT INSTRUCTIONS

BIOMECHANICS
 Definition

of terms

FORCE
A force is that which changes or tends to
change the position of rest of a body or its
uniform motion in straight line .






Definition of terms
CENTER OF MASS

A FREE BODY IN SPACE HAS A SINGLE
POINT WHERE ALL ITS MASS IS
CENTERED. WHEN A FORCE IS APPLIED
THROUGH THE C.O.M. IT CAUSES ALL
POINTS IN THE BODY TO MOVE THE
SAME AMOUNT IN THE SAME DIRECTION
AS THE LINE OF FORCE (TRANSLATION)

CENTER OF RESISTANCE
THE ANALOGOUS CENTER OF MASS OF A
RESTRAINED BODY e.g. A TOOTH
SUPPORTED BY ALVEOLAR BONE IS
CALLED CENTER OF RESISTANCE.



 Or
 Is

that point through which the resultant of
constraining forces acting upon it may be
considered to act
 Or a point at which resistance to movement
can be concentrated for mathematical
analysis


CENTER (C
Res) OF
RESISTANCE
OF MAXILLARY
MOLAR

CENTER OF
RESISTANCE www.indiandentalacademy.com

CENTER OR
RESISTANCE
(C Res) OF
MAXILLA

 Definition

of terms
 CENTER OF ROTATION
It is an arbitary point about which a body
appears to have rotated as determined from
its initial and final position. The center of
rotation is located at variable points
depending on how far the force is applied.


MOMENT OF A FORCE
Defined as the product of force times the
perpendicular distance from the point of force
application to the center of resistance.
Tendency to rotate resulting from a force NOT
acting at the center of resistance is called
MOMENT OF A FORCE.


MOMENT = FORCE X PERENDICULAR DISTENCE

TOOTH MOVEMENTS RESULTING FROM FORCES
NOT ACTING THROUGH THE CRes IS A
COMBINATION OF ROTATION AND TRANSLATION

 Definition

of terms

COUPLE
Two non-collinear forces equal in magnitude
and opposite in direction.
Application of a couple causes pure rotation



MOMENT OF A COUPLE
Tendency to rotate when a couple is applied.


Moment of couple= one of the forces of couple
X perendicular distance
between two parallel forces of coule


LINE OF ACTION
 Line

of action of a force is that line
connecting the point of origin of force ( head
cap or neck) to the point of attachment
( hook on outer bow.
 The resultant force acting on banded molar
tooth is the relationship of line of action to
centre of resitance of tooth


 The

line of action depend on the point of
attachment (hook on the outer bow)


Teeth can be moved in 3 planes


Sagittal plane



Coronal plane



Transverse plane


Sagittal plane
 point

of attachment (outer bow hook)can
be anywhere on the line a-p axis ,V-Vi
axis in the saggital rectangle


V
P

A
Vi

Shape of outer bow is of no
consequence


Point of attachment can be varied by
 Varying

the length of outer bow

 Varying

the angle between inner and outer

bow
 combination


Cervical headgear for bodily
movement


Location of point of attachment


Distal force component
 Distal

force is maximum when line of action
is horizontal,rather than inclined, and passes
through centre of resistance.


Minimal inclined line of action


Steep line of action


Coronal plane
 The

magnitude of the intrusive or extrusive
vertical component is dependent upon the
inclination or steepness of line of action
 Steeper the line of action more extrusive or
intrusive vertical component
 Horizontal forces neither extrude or intrude


 Since

line of action passes bucally during
intrusion or extrusion these teeth will tend to
roll.
 Buccal crown movement during intrusion and
palatal crown movement during extrusion
 The moment or rotation effect is depend
upon molar tube height from centre of
resistence
 Soldering a palatal bar can solve this
problem

Palatal bar for bodily intrusion


Transverse plane
 Tooth

can be moved distally and medially or
laterally



expansion or contraction of inner arch of
face bow will be translate the crown of molar
medially or laterally


Lateral forces on molar during
extraoral force application


Lateral forces in case of
symmetrical face bow


Offset joint in face bow

70

18

16

14

16


 This

difference is due to flexibility of arm and
not due to offset joint

 If


outer bow is rigid force will be same

the rationale of unequal force distribution to
molars relates to the distance of outer bow to
the mid sagittal plane

Symmetrical soldered outerbow with
different arm length


 In

clinical practice lengthening one arm or
bending it out will create more distal force on
that side
 A mild expansion of inner bow wil counteract
the lateral force on lengthen side


Swivel type of unilateral extraoral face
bow


Most suitable without
any lateral force


HEADGEARS IN COMBINATION
THERAPY
 FUNCTIONAL

APPLIANCE
 EXTRAORAL FORCE
 CLASS II DIV I CASES WITH
 More excessive vertical growth pattern
 Excessive lower anterior facial height


 ACTIVATOR

WITH HEADGEAR
 Hasund (1969)
 Stockfisch (1977)
 Stockli (1982)
 Pfeiffer (1984)
 Grobety (1984)


PFEIFFER-GROBETY TECHNIQUE


STOCKLI-TEUSCHER APPLIANCE


HEADGEAR WITH BIONATOR




FRANKEL APPLIANCE
WITH HEADGEAR


Thank you
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