Chincup and facemask biomechanics and application class 3 reverse pool headgear

1. PRESENTEDBY–Dr. J
FACEMASK AND CHINCUP

2. ⦁ INTRODUCTION
⦁ HISTORICAL BACKGOUND
⦁ FACEMASK AND ITS TYPES
⦁ CHIN CUP
⦁ CONCLUSION

3.  Facial mask is effective in most developing Class III
patients, because the appliance system affects virtually
all areas contributing to Class III.

4. History
• A reverse pull head gear basically consists of a rigid extra-oral framework which takes
anchorage from the chin or forehead or both for the anterior traction of the maxilla using
extra-oral elastics which generate large amounts of force upto 1 kg or more
• .
• Although the facial mast was developed over 100 years ago. Hickham claims he was the first
to use a reverse headgear. However, this modality was made popular by Delairc around the
same time. This approach was used infrequently until reintroduced by Delaire in the late
1960s for the treatment of cleft patients. Interest in the facial mask in the United States later
was stimulated by Petit through his studies conducted at Baylor University

5. Components of Orthopedic Facial Mask Therapy
The component of facial mask appliance
1)Facial Mask
Chin cup
Forehead cap
Metal frame
2)Intra-oral appliance
Bonded maxillary splint
3)Heavy elastic

6. . Frontal view of the Petit facial mask. Note
that the elastics converge on and attach to the
crossbow immediately adjacent to the central
support bar. The positions of the forehead &
chin pads are adjustable
The lateral view of the orthopedic facial
mask. Note the downward direction of
pull of the elastics. The direction of the
pull can be adjusted by raising or
lowering the crossbar, however, the
elastics must not interfere with the
functional of the lips.

7. Types of facemask
• Protraction head gear by 'Hickham
Face mask of Delaire

8. Petit type of face mask

9. New Maxillary Protractor: Developed by Dr. Conte. This reverse headgear exerts a selective
propulsive force on the maxilla with no deleterious effect on the T.M.J.
Because the appliance has got only one point of resistance, (i.e. from the patient frontal bone).
There wont be any compression force against the mandible. So it can be used in whom a retrusive
mandibular force could be harmful to the joint.
Indication: Appliance is comfortable to wear. In patient with Class III malocclusion with
maxillary deficiency. Not suitable for patient with ideal maxilla and excessive mandibular growth

10. Indications:
1. It can be used in a growing patient having a prognathic mandible and a retrusive
axilla. It aids in pulling the maxillary structures forward and pushing the mandibular
structures backward.
2. It can be used for bending the condylar neck for stimulating temporomandibular
joint adaptations to posterior displacement of the chin.
3. It can also be used for selective rearrangement of the palatal shelves in cleft patients.
4. I can be used in correction of post-surgical relapse after osteotomies (or
uncontrolled post-surgical adaptations).
5. It can be used to treat certain accessory problems associated with nose morphology
such as lateral deviations.

11. Treatment Effects Produced by Facial Mask Therapy:
1. Correction of CO-CR discrepancy. This correction is immediate and usually is
observed in pseudo Class III patients.
2. Maxillary skeletal protraction. Usually 1 – 3 mm of forward movement of the
maxillary is observed.
3. Forward movement of the maxillary dentition.
4. Lingual tipping of the lower incisors. This tipping often occurs as a pre-existing
anterior crossbite is being corrected.
5. Backward rotation of the mandible is relation to the cranial base. In instances in
which the patient begins treatment with a short or neutral lower anterior facial
height, this change obviously is advantageous. In instances in which a patient has a
long lower anterior facial height at the beginning of treatment, this treatment effect
may be undesirable.
6. Favorable changes in mandibular growth, at least over the short – term. Condylar
growth in a forward direction can be associated with reduced increments in
mandibular length.

12. According to Proffit:
Clinical Management of Facemask Treatment. Generally, it is better to defer
maxillary protraction until the permanent first molars have erupted and can be
incorporated into the anchorage unit. Following palatal expansion or in conjunction with it,
a facemask that obtains anchorage from the forehead and chin (Fig.24) is used to exert a
forward force on the maxilla via elastics that attach to a maxillary appliance. To resist
tooth movement as much as possible, the maxillary teeth should be splinted together as a
single unit. The maxillary appliance can be banded, bonded, or removable. A removable
plastic splint that covers the occlusal surfaces of the teeth often is satisfactory. Multiple
clasps combined with plastic that extends over the incisal edges usually provide adequate
retention.

13. 12 Forward traction against the maxilla typically has three effects: (1) some forward movement of the maxilla, the
amount depending to a large extent on the patients age; (2) forward movement of the maxillary teeth relative to the
maxilla; and (3) downward and backward rotation of the mandible because of the reciprocal force placed against the
chin.

14.  The orthopedic facial mask system
component:
has 3 basic
1) Facial mask,
2) Bonded maxillary splint and
3) Elastics.

15.  The facial mask is an extraoral device
 It consists of 2 caps which contact the soft tissue in the
forehead and chin regions.

16.  The pads are made up of acrylic and are lined with a
soft closed-cell foam that is non-absorbent, easily
cleaned and replaceable.
 The pads are connected by a midline framework made
from a round, contoured length of 0.25” stainless steel
with nuts on each end.

17.  The positions of the pads are adjustable through the
loosening and tightening of a set screw.
 The midline framework also can be bent to conform
better to the outline of the face of the individual patient.

18.  In the center of the midline framework is a crossbar
made from 0.075” stainless steel that is secured to the
main framework by a set screw.
 It allows the position of the crossbar to be adjusted
vertically. The ends of the crossbar are contoured for
patient’s safety.

20.  The splint is activated once per day until the desired
increase in transverse width has been achieved.
 In patients - no increase in transverse dimension is
desired - activated for 8-10 days
- To disrupt the maxillary sutural system
- To promote maxillary protraction.

21.  the facial mask - full time basis for 4-6 months, and
then it can be worn on a night-time only basis for an
additional period of time.
 Maintaine oral hygine .
 Visite within 3-5 weeks .

22.  The facial mask is secured to the face by stretching elastics
from the hooks on the maxillary splint to the crossbow of
the facial mask.
 Heavy forces are generated, usually through the use of a
sequence of elastics, ultimately resulting in a 18oz force
being generated by 5/16” elastics.
 Lighter forces may be used during the break-in period, but
forces should be increased as the patient adjusts to the
appliance

24.  At the time of the delivery- 3/8” - 8oz elastics first 2
weeks
 After 2 weeks - ½”. 14oz e.
 Maximum force is delivered through the use of 5/16”
elastics.

26. ⦁ Developed in 1960 by
Delaire
⦁ Design was squarish and
with rigid metal
framework

28. of chin cup and
⦁ Consists
forehead
vertical
midline
cap with single
rod
from
running in
chin to
forehead cap

29.  Facial mask especially when combined with a
maxillary anchorage unit can produce one or more of
the following treatment effects:
1) Correction of CO-CR discrepancy. This correction is
immediate and usually observed in pseudo class 3
patients.
2) Maxillary skeletal protraction. Usually 1-2mm of
forward movement of the maxilla is observed.

30. 3) Forward movement of the maxillary dentition.
4) Lingual tipping of the lower incisors. This tipping
often occurs as a pre-existing anterior crossbite is
being corrected.
5) Redirection of mandibular growth in a more vertical
direction.

31.  The ideal stage of dental development in which to begin
facial mask therapy is at the time of eruption of the upper
permanent central incisor.
 Usually ,the lower incisors have already erupted into the
occlusion.

32.  The achievement of a positive horizontal and vertical
overlap of the incisors during treatment is essential in
providing an environment that will help maintain the
achieved anteroposterior correction of the original class
III malocclusion.
 Optimally, the patient is instructed to wear the facial
mask on a full-time basis except during meals.

33.  Young patients (5-9yr old) usually can follow this regimen.
 In older pts, full-time wear may not be possible.
 Particularly if the patient is told the full-time wear will last
only 4-6 months.

34.  The facial mask should be discontinued immediately if
the pt complains of any symptoms of
temporomandibular disorders.
 Immediate discontinuance of the appliance usually
results in a reversal of the symptomatology.

35.  Demet Kaya, Ilken Kocadereli, Bahadir Kan, and Ferda
Tasar studied the effects of facemask treatment
anchored with miniplates after alternate rapid maxillary
expansions in July 2011 (Angle Orthod.)

36.  It is a relatively old orthopedic appliance.
 Introduced by Oppenheim.

37. ⦁ This is not analogous to the use of extraoral force
against the maxilla because there are no mandibular
sutures to influence.
⦁ Mandibular condyle - growth site
⦁ Condylar growth is largely a response to translation
as surrounding tissues grow,

38. ⦁ There are two major ways to direct force against the
mandible.
Heavy force aimed directly at the condylar area, or lighter force aimed below the
condyle to produce downward rotation of the mandible.

39. Diagrammatic representation of a typical response to chin cup therapy,
showing the downward and backward rotation of the mandible
accompanied by an increase in facial height.

40. ⦁ When extraoral force is applied against the chin, it is
difficult to avoid tipping the lower incisors lingually.
⦁ If the mandibular dentition was protrusive initially,
uprighting of the incisors is desirable

41.  Chin cups are divided into 2 types:
1) Occipital-pull chin cup (used in mandibular
prognathism)

42. a b

43. a b

44. 2) Vertical-pull chin cup (used in cases of steep
mandibular plane angle and excessive anterior facial
height)

45. According to Samir E. Bishara :
Effect on Mandibular Growth. The orthopedic effects of a chin cup on
the mandibular include (1) redirection of mandibular growth vertically, (2) backward
repositioning (rotation) of the mandible, and (3) remodeling of the mandible with
closure of gonial angle. To date, there is no agreement in the literature as to whether chin
cup therapy may or may not inhibit the growth of the mandible. however, chin cup
theryapy has been shown to produce a change in the mandible associated with a
downward and backward rotation and a decrease in the angle of the mandible. In
addition, there is less incremental increase in mandibular length together with posterior
movement of B point and pogonion. Because of the backward mandibular rotation,
control of the vertical growth during chin cup treatment is difficult to manage.

46. Effects of Maxillary Growth. Some studies have indicated that a chin cup appliance has
no effect on the anteroposterior growth of the maxilla.
However, Uner, Yuksel, and Uncuncu showed that early correction of an anteriro
crossbite with a chin cup appliance prevents retardation of anteroposterior maxillary
growth
.
Sugawara et al compared the growth changes of patients after chin cup treatment with
control subjects and reported that, at age 17, the midface is more deficient in patients of
the control groups than in those of the treatment groups

47.  At the time of appliance delivery, the force level of 150-
300 grams per side is used initially.
 Over the next 2 months, the force level is increased to
450-700 grams per side (if the force is directed through the
condyles and slightly less if force is directed below the
condyle)

48.  Patient is instructed to wear the chin cup 14hours per
day with an acceptable range of wear being 10-16 hours
per day.
 After correction of a preexisting anterior crossbite has
been accomplished, the patient wears the appliance
during the night only as a retention appliance.

49.  Both the occipital and vertical pull chin cups create
pressure on the temporo-mandibular joint region.
 If any signs and symptoms of TM disorders are noted,
the use of the chin cup should be discontinued
immediately.

50. ⦁ Heavy intermittent force is less likely to produce
damage to roots of teeth, probably because the
stimulus for undermining resorption is diluted during
the times that the heavy force is removed.

51.  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.