HEAD GEAR
DR. ABDUL JABBAR
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Means of applying posterior directed forces
to teeth and skeletal structures from an extra
oral source
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Headgear
Introduced in late 1800s
Abandoned as it was thought that intraoral elastics would be as effective
Reintroduced in 1940s after cephalometric
developed
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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
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Force is generated by head cap or neck strap
through ;
springs
Elastic bands
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Force is delivered to the teeth by ;
Face bow
J Hooks
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classification
Distalising HG: direction of elastic
traction has a distal component
Types : Occipital directed ( high) pull
Combination pull
Cervical directed (low) pull
J-hook HG
Asymmetric HG
HG to mandible
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
High Pull Headgear
Skeletal Class II with prognathic maxilla
High Angle case
Growing ages

Straight Pull Headgear
Skeletal Class II with prognathic maxilla
normal Angle case
Growing ages

Cervical Pull Headgear
Skeletal Class II with prognathic maxilla
Low Angle case
Growing ages
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High pull HG
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Combination pull HG
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Low pull HG
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J Hook HG
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A. Single pull to maxillary dentition
B. Attachment of the J hooks to both maxillary and
mandibular dental arches.
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Asymmetric HG
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Components
Head cap / neck strap
Elastics
Face bow (Inner bow, outer bow and U
loop)
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Uses: dental
Anchorage
Distalisation – single or blocks of teeth
Intrusion -- single or blocks of teeth
Extrusion
Asymmetric movement
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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
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Factors influencing effect
Direction of force
Duration of force
Magnitude of force
Centers of rotation
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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
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Duration and magnitude of force
Tooth movement
Principle : smaller forces for longer duration
100 --- 200 gm / side
14 --- 16 hrs
Anchorage
250 --- 300 gm / side
10 hrs min.
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Magnitude of force is determined by a
Strain-gauge
Spring loaded assembly comes with a builtin force indicator
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FORCE MEASURING DEVICE
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Centers of rotation
Single rooted teeth ----- centroid
6_ ----- trifurcation
Maxilla ----- b/w roots of 4&5
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Resolution of forces:horizontally
Force thru center of resistance ----- bodily
movement
Force above center of resistance ----- distal
root tipping
Force below center of resistance ----- mesial
root tipping
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Resolution of forces:
Vertically
Above occlusal plane ----- intrudes teeth
Below occlusal plane ----- extrudes teeth
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Problems with HG
Tooth- 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
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Problems with HG
Patient related
Co-operation
biological variability
growth may be unfavorable
Extra / intra-oral injuries
Pain
Difficulty with insertion
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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
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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
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Safety
No 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
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THANK YOU
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