This document discusses various orthodontic appliances used under the guidance of Dr. Mridula Trehan. It provides details on commonly used appliances like headgear, face mask, and chin cup. For headgear, it describes the components of the face bow assembly and different types of headgears based on the site of anchorage. Face mask is discussed in terms of its indications, parts, biomechanics and different types. Chin cup is summarized focusing on its principle, parts, types and fabrication process. Force magnitude and duration of wear for various appliances is also highlighted.

1. ORTHOPAEDIC
APPLIANCES
UNDER THE GUIDANCE OF
DR MRIDULA TREHAN

2. BASIS FOR
ORTHOPAEDIC
APPLIANCES
• Force of 500-1000 gm total
• Force duration atleast 12 hours per
day
• Treatment duration- 12-18 months

3. COMMONLY USED
ORTHOPAEDIC
APPLIANCES
1) HEADGEAR
2) FACE MASK
3) CHIN CUP

4. HEAD GEAR
• Most commonly used
• Uses:
1. Orthopaedic effect
2. Anchorage augmentation
3. Distalization of molars
4. Molar rotation
5. Space maintenance

5. COMPONENTS OF HEAD
GEAR-FACE BOW
ASSEMBLY
1) FACE BOW
2) FORCE ELEMENT
3) HEAD CAP OR CERVICAL STRAP

6. FACE BOW
• Metallic component
that helps in
transmitting extra-
oral forces onto the
posterior teeth
• Consists of:
1. Outer bow
2. Inner bow
3. Junction

7. OUTER BOW
• Formed of .055”S.S. wire in a
paraboloid shape to fit the contours
of face and cheeks at the level of
the lips
• Can be short, medium or long
• Distal end is curved to form a hook

8. INNER BOW
• Made of .045” S.S. wire
• Contoured to shape of maxillary arch
• Inserted into buccal tubes

9. THE JUNCTION
• Rigid joint of outer & inner bow
• Can be:
1. Simple soldered
2. Wire wrapped soldered
3. Welded
Placed at midline of bows

10. FORCE ELEMENT
• That part of assembly which provides
force to bring about desired effect
• Comprises of elastic or any other
stretchable material
• Connects face bow to neck strap or
head cap

11. HEAD CAP OR CERVICAL
STRAP
• Appliance takes anchorage from skull
or back of neck or a combination of
the two

12. PRINCIPLES IN USE OF
HEAD GEARS
• CENTRE OF RESISTANCE OF
DENTITION:
• Force passes through centre of
resistance- bodily movement
• Below centre of resistance-distal crown
tipping
• Above centre of resistance-distal root
tipping

13. • CENTRE OF RESISTANCE OF
MAXILLARY DENTAL ARCH: located
above roots of premolars
• If force passes through centre of
resistance of maxilla-produces translation
of maxilla in a distal direction
• Forces passing above or below cause
rotation of maxilla

14. • SITE OF ANCHORAGE:
• Occipital headgears produce a
superior and distal force on teeth
and maxilla
• Cervical headgears produce an
inferior and distal force on teeth and
maxilla

15. TYPES OF HEAD GEARS
• Based on site of anchorage:
i. Occipital head gear
ii. Cervical head gear
iii. Combination head gear

16. OCCIPITAL HEAD GEAR
• Derives anchorage
from back of head
• Places a distal and
upward force on
maxillary teeth and
maxilla

17. CERVICAL HEADGEAR
• Anchorage from
nape of neck
• Produces a distal
and downward
force against
maxillary teeth
and maxilla
• Indicated in low
• mandibular
• angle cases

18. COMBINATION HEAD
GEAR
• Both occipital and
cervical headgears are
combined and
connected to a face
bow.
• When force is equal
from both headgears a
distal and slightly
upward force is placed
on maxillary teeth and
maxilla.

19. FACE MASK
• Also called reverse
pull headgear or
forward pull
headgear
• Given by Hickham
in 1972 but made
popular by Delaire

20. INDICATIONS
1. Growing patient with prognathic
mandible and retrusive maxilla
2. For rearrangement of palatal shelves in
Cleft palate patients
3. Correction of postsurgical relapse
after osteotomy.
4. Treatment of accessory problems
associated with nose morphology such
as lateral deviations.

21. SITES OF ANCHORAGE
1. From chin
2. From forehead
3. From chin and forehead

22. BIOMECHANICAL
CONSIDERATIONS
i. AMOUNT OF FORCE: About 450gm/side
ii. DIRECTION OF FORCE:A 15-20 degree
downward pull to the occlusal plane to
produce forward translation of
maxilla.If parallel to occlusal plane-also
causes upward rotation of maxilla
iii. FREQUENCY OF USE:12-14 hours/day

23. PARTS OF REVERSE
PULL HEADGEAR
• Chin cap
• Forehead cap
• Elastics- To apply a forward traction
on the upper arch.
• Intra-oral appliance:usually a
multibanded appliance with rigid wire
• Metal frame

24. TYPES OF REVERSE
PULL HEADGEAR
• FACE MASK OF
DELAIRE:Popularised
by Delaire in 1960’s
• Appliance made up of
a squarish rigid wire
framework
• Forehead cap and chin
cup
• Wire running in front
of mouth used for
elastic attachment

25. TUBINGER FACE MASK
• 2 rods originate
from chin cup which
run in the midline
and is shaped to
avoid interference
of nose
• Superior end of
rods attached to
forehead cap from
which elastics
encircle the head
• Cross bar extends
in front of mouth
which is used to
engage elastics

26. PETIT TYPE OF FACE
MASK
• Consists of a chin
cup and forehead
cap with a single
rod running in
midline
• Cross bar at level
of mouth is used to
engage elastics

27. CHIN CUP
• Used by Cellier and Fox early in 19th
century
• Extra-oral orthopaedic device used
to restrict forward growth of
mandible

28. PRINCIPLE
• Changes the direction of mandibular
growth rotating the chin down and
back
• Also causes lingual tipping of lower
incisors

29. PARTS
• Chin cup
• Headgear
• Elastic strap that connects chin cup
with headgear

30. TYPES OF CHIN CUPS
• OCCIPITAL PULL CHIN CUP
• VERTICAL PULL CHIN CUP

31. OCCIPITAL PULL CHIN
CUP
• Most commonly used
• Used in Cl III
malocclusion with mild
to moderate
mandibular
prognathism who can
bring incisors in edge
to edge
• Also in patients with
slight protrusive lower
incisors

32. VERTICAL PULL CHIN
CUP
• Derives anchorage
from parietal region
of head
• Indicated in patients
with steep mandibular
planes and increased
lower anterior facial
height
• These patients usually
exhibit an anterior
open bite

33. FABRICATION OF
CHIN CUP
• Can be fabricated individually or pre-
fabricated commercially available
chin cups can be used
• Can be made of acrylic or commercial
metal or plastic cup can be used

34. • Ideal patient for chin cup treatment:
• Mild skeletal problem with ability to bring
incisors end to end or nearly so
• Short vertical face height
• Normally positioned or protrusive but not
retrusive lower incisors
• As a guideline, more than 4mm reverse
overjet in a preadolescent child indicates
that surgery eventually will be needed

35. FORCE MAGNITUDE AND
DURATION OF WEAR
• At the time of appliance delivery a
force of 150-300 gm per side is used
• Over the next 2 months force is
gradually increased to 450-700gm
per side
• Patient is asked to wear appliance for
12-14 hours per day