HEADGEARRESOURCE FACULTIES DR PRABHAT RANJAN POKHARELASSOCIATED PROFESSOR

DR RAJESH GYAWALI ASSISTANT PROFESSOR

DR JAMAL GIRIASSISTANT PROFESSOR

DEPARTMENT OF ORTHODONTICS

PRESENTED BYSANTOSH PANDITROLL NO:502BATCH 2011bless288maniac@gmail.com

CONTENTS

• INTRODUCTION• MECHANISM OF ACTION• CLASSIFICATION• COMPONENTS• USES• FACTORS INFLUENCING EFFECT• PROBLEMS WITH HEAD GEAR• INSTRUCTIONS

INTRODUCTION

Introduced in late 1800s

Abandoned as it was thought that intra- oral elastics would be as effective

Reintroduced in 1940s after cephalometric developed

Means of applying posterior directed forces to teeth and skeletal structures from an extra oral

source

MECHANISM OF ACTION

Growth modification by changing the pattern of bone

apposition at the sutures

CL II correction is obtained as the mandible grows forward

normally while maxillary growth is restrained

Favorable mandibular growth is a must for CL II correction

with HG use

Force is generated by head cap or neck strap through ;

a)springs

b)Elastic bands

Force is delivered to the teeth by ;

a)Face bow

b)J Hooks

CLASSIFICATION

Distalising HG: direction of elastic traction has a distal component

Types : Occipital directed ( high) pull Combination pull Cervical directed (low) pull

Asymmetric HG

Vertical pull HG

OCCIPITAL(HIGH PULL)HEADGEAR

DERIVES ANCHORAGE FROM BACK OF HEAD

PRODUCE DISTAL AND SUPERIORLY DIRECTED FORCE ON MAXILLA AND ITS DENTITION

PRODUCE MORE VERTICALLY DIRECTED FORCE SO USED IN INDIVIDUAL IN WHOM AN INCRESE IN

VERTICAL DIMENSION IS TO BE AVOIDED

INDICATED IN LONG FACE CLASS II PATIENT WITH TENDENCY OF OPEN BITE

HIGH PULL HEADGEAR

COMBINATION(STRAIGHT PULL)HEAD GEAR

OCCIPITAL AND CERVICAL ANCHORAGE IS COMBINED

WHEN FORCE EXERTED ARE EQUAL DISTAL AND SLIGHT UPWARD FORCE IS EXERTED

ON MAXILLA AND ITS DENTITION

FORCE DIRECTION CAN BE ALTERED BY ALTERING FORCE DERIVED FROM HEAD

CAP AND NECK STRAP

COMBINATION PULL HEADGEAR

CERVICAL(LOW PULL)HEADGEAR

DERIVES ANCHORAGE FROM NAPE OF NECK

CAUSE EXTRUSION OF MAXILLARY MOLAR LEADING TO INCREASE IN

LOWER FACIAL HEIGHT

INDICATED IN LOWER MANDIBULAR ANGLE

LOW PULL HEADGEAR

ASYMMETRICAL HEADGEARS

USED WHEN DIFFERENTIAL ANCHORAGE IS REQUIRED ON BOTH SIDE OF MAXILLARY

ARCH

DIFFERENTIAL VALUE ARE PRODUCED BY ALTERING LENGTH OF OUTER BOW AND

ANGLE BETWEEN AOTER AND INNER BOW

EG:USED IN CLASS II IN ONE SIDE AND CLASS II ON OTHER SIDE

VERTICAL PULL HEADGEAR

DERIVES ANCHORAGE FROM PARIETAL REGION

PRODUCE VERTICALLY DIRECTED FORCE ON MAXILLA AND ITS DENTITION

USED TO PRODUCE INTRUSIVE FORCE ON ANTERIOR REGION OF MAXILLA

USED TO TREAT VERTICAL MAXILLARY EXCESS AND GUMMY SMILE

COMPONENTS

FACE BOW

THE FORCE ELEMENT

THE HEAD CAP OR CERVICAL STRAP

FACE BOW

TWO TYPES

• HAS METALLIC COMPONENT IN TRANSMITTING EXTRAORAL FORCE ONTO POSTERIOR TEETH

• CONSISTS-• OUTER BOW• INNER BOW• JUNCTION

A)INNER-OUTER

BOW TYPE

OUTER BOW AND ITS TYPES

SHORT

OUTER BOW IS

LESSER IN LENGTH

THAN INNER BOW

MEDIUM

OUTER BOW

LENGTH IS EQUAL TO

INNER BOW

LONG

OUTER BOW IS LONGER

THAN INNER BOW

J HOOK TYPE OF FACE BOW

CONSISTS OF TWO 0.072 INCH CURVED WIRES WHOSE ENDS

FORM HOOKS

NORMAL SITE OF ATTACHMENT IS BETWEEN THE LATERAL INCISOR

AND CANINE

USED FOR RETRACTION OF MAXILLARY ANTERIORS AND HAVE LIMITED ORTHOPEDIC INDCATIONS

FORCE ELEMENTPROVIDES FORCE TO

BRING ABOUT DESIRED EFFECT

COMPRISE-SPRINGS,ELASTICS

AND OTHER STRETCHABLE

MATERIALS

CONNECTS FACE BOW TO THE HEAD

CAP OR NECK STRAP

HEAD CAP OR CERVICAL

STRAPTAKES ANCHORAGE FROM RIGID

BONES OF SKULL OR FROM BACK OF THE NECK BY MEANS OF HEAD CAP OR NECK STRAP OR COMBINATION

SELECTION DEPENDS ON INDIVIDUAL PATIENTS NEEDS

USES-DENTAL

Anchorage

Distalisation – single or blocks of teeth

Intrusion -- single or blocks of teeth

Extrusion

Asymmetric movement

USES-SKELETAL

growth modification

maxilla --- suppression which is permanent even after treatment has ceased

mandible --- suppression, retrusion of the chin during chin cap treatment.however catch-up mandibular growth may occur during or after pubertal growth period

Factors influencing

effectDirection of force

Duration of force

Magnitude of force

Centers of rotation

Duration and magnitude of

force

Orthopedic effect

Principle: higher forces for comparatively smaller duration

12 ---16 oz or 350-----450 gm / side

10 ---12 hrs

Duration and magnitude of

forceTooth movement

Principle : smaller forces for longer duration

100 --- 200 gm / side

14 --- 16 hrs

Anchorage

250 --- 300 gm / side

10 hrs min

Magnitude of force is determined by a Strain-

gauge

Spring loaded assembly comes with a built-in

force indicator

FORCE MEASURING

DEVICE

Centers of rotation

Single rooted teeth ----- centroid

6_ ----- trifurcation

Maxilla ----- b/w roots of 4&5

Resolution of forces:horizont

allyForce through center of resistance

----- bodily movement

Force above center of resistance ----- distal root tipping

Force below center of resistance ----- mesial root tipping

Resolution of forces:

Vertically

Above occlusal plane ----- intrudes teeth

Below occlusal plane ----- extrudes teeth

Problems with HGTooth- related

Unwanted tooth movement

Tipping

Extrusion of 6_ may cause clockwise rotation of mand. Pt. Becomes more CLII

Buccal rolling of 6_ with high pull HG

Cross bite on side of movement with asymmetric HG

Lingual tipping of lower incisors, clockwise rotation of mand. & increased

LAFH with chin cup therapy

Root resorption possibly with J hook HG

Problems with HGPatient related

Co-operation

biological variability

growth may be unfavorable

Extra / intra-oral injuries

Pain

Difficulty with insertion

Assessment of patient compliance at every visit

Check for signs of use intra orally as well as extra orally

Hand out Time-sheets for record of wear

Offer reward

Extra oral injuries include injuries to eyes , eyelids, nose etc.

Most common are eye injuries

Catapult type of injury very common while playing

Disengagement of face bow during sleep

SafetyNo single safety HG is best

Should use safety face bow and release mechanism together

Written instructions must be given to patient

Risks involved should be explained

told to seek medical advice if any problem arises

INSTRUCTIONS

Wear HG a minimum of 12-14 hours every day. HG does not have to be worn a consecutive 14 hours. It can be worn a minimum of 1 hour at a time, as long

at it equals 12-14 per day.

Do not wear HG during rough play or sports. This could result in injury to you.

Some temporary discomfort may be experienced during the first night or two. Molar teeth may become tender and even a little loose. This is

normal

When not wearing your HG, please keep it in the case . If the facebow of your HG becomes lost or bent,contact dentist.

Never try to pull the HG off without first un-hooking the safety strap.

Please place and remove the HG the same way advised

DON’T SIT AROUND MOPING AND WAITING FOR YOUR LUCK TO COME BACK GO OUT AND FIGHT FOR IT IT WILL SOON BE BACK