6. CLASS II
Prognathic maxilla &
Retrognathic mandible
Prognathic maxilla &
Orthognathic mandible
Orthognathic maxilla and
Retrognathic mandible
CLASS III
Retrognathic maxilla &
Prognathic mandible
Retrognathic maxilla &
Orthognathic mandible
Orthognathic maxilla &
Prognathic mandible
7. WHAT ARE FUNCTIONAL APPLIANCES?
Functional appliances are defined as
loose fitting or passive appliances,
which harness natural forces of the
oro-facial musculature that are
transmitted to the teeth and
alveolar bone through the medium
of the appliance.
10. CLASSIFICATION OF FUNCTIONAL
APPLIANCES - III
Functional
appliance
GROUP 1 – Force is directly transmitted
to/eliminated from the teeth. Eg. ORAL SCREEN
GROUP II – It repositions the mandible and
transfers force to the teeth and other structures.
Eg.BIONATOR
GROUP III – It repositions the mandible and works
within the vestibule and not near the dental arch.
Eg. FRANKEL REGULATOR
11. TREATMENT PRINCIPLES
• The compressive stress and strain
acts on the structures involved in
dento-alveolar region thereby
altering the form.
Force
application
• By elimination of abnormal and
restrictive environmental
influences on the dentition
thereby allowing optimal
development.
Force
elimination
14. FUNCTIONAL COMPONENTS OF
AN APPLIANCE
Bite planes (Anterior/Posterior)
– vertical control by
eruption/intrusion of teeth
Shields or screens
– muscle balance
Construction bite
– mandibular repositioning
16. ACTION OF FUNCTIONAL APPLIANCES
• Orthopedic changes –
– Accelerated growth in the condylar region
– They can bring remodeling in the glenoid fossa
– They can have restrictive effect on jaws
– Can change the direction of growth of the jaws
• Dentofacial changes –
– In the sagittal plane, it allows upper anteriors to tip
lingually and lower anteriors to tip labially.
– In the transverse plane, expansion of dental arches
with screws or by shielding the buccal muscles away
from dental arches( screens).
– In the vertical plane, it allows selective eruption of
teeth
• Muscular changes –
– improve tonicity of the oro-facial musculature
17. CASE SELECTION
• Age: only in a growing patient
around the pubertal growth
spurt
• Skeletal CLASS II or CLASS III
• Dental consideration – Almost
well aligned arches : very
minimal crowding
• POSITIVE VTO
19. VESTIBULAR SCREEN
• This was introduced by Newell in
1912.
• It is a simple myofunctional appliance
with a curved shield of acrylic placed
in the labial vestibule
•PRINCIPLE:
–Force application
–Force elimination
20. INDICATIONS
• Mostly used in patients with mouth
breathing habit. It can also be used in
habits such as, thumb sucking, tongue
thrusting, lip biting and cheek biting.
• It can be used to perform muscle
exercises in hypotonic upper lip
• It can be used to correct mild anterior
proclination.
22. LIP BUMPER
• SYNONYMS:
–Lip plumber
–Modified vestibular screen
–Combined Removable-fixed appliance
• PRINCIPLE:
–Force application
–Force elimination
• It can be used in both maxilla
and mandible to shield the lips
away from the teeth.
24. INDICATIONS
• In patients with lower lip habits such as lip biting
• In patients with hyperactive mentalis activity
• It can be used to augment mandibular anchorage by
giving a distal directed force.
• It can be used as space maintainers to prevent the
mesial migration of the molars.
25.
26. ACTIVATOR
• Activator is a loose fitting appliance which was designed by
ANDREASEN AND HAUPL to correct retrognathic
mandible.
• The development of the appliance started with the concept of
'bite jumping' introduced by Norman Kingsley (1879). He
used anterior inclined plane, which guided the mandible into a
forward position when the patient closed on it.
28. INDICATIONS AND CONTRAINDICATIONS
INDICATIONS
• Actively growing individual with
favorable growth pattern are good
candidates for the activator therapy.
• treatment of various conditions like:
– Class II division 1 malocclusion
– Class II division 2 malocclusion
– Class IIl malocclusion
– Class I open bite malocclusion
– Class I deep bite malocclusion
– Children with decreased facial height
CONTRAINDICATIONS
• Cannot be used in correction of
crowded teeth
• Cannot be used in children with
excess lower facial height
• Cannot be given in cases with lower
proclination
• In case of nasal stenosis
29. COMPONENTS OF ACTIVATOR
• LABIAL BOW
• ACRYLIC PART –
– Maxillary part
– Mandibular part
– Interocclusal part
• EXPANSION SCREW
31. CONSTRUCTION BITE
• It is an inter-maxillary wax record used to relate the mandible to the maxilla.This is done to improve
the skeletal inter-jaw relationship.
• In most cases bite opening is by 2-3 mm and advancement is by 4-5 mm.
• For CLASS III cases, horizontal retraction is 2mm and vertical opening is 5mm.
CLASS II
SKELETAL
CORRECTION
H –TYPE
ACTIVATOR
MODERATETYPE
ACTIVATOR
V –TYPE
ACTIVATOR
Andresen-Haupl Herren Woodside
Horizontal
advancement
7 – 8mm 3 – 5mm 0 – 3mm
Vertical opening 2 – 3mm 4 – 6mm 8 – 10mm
34. TRIMMING OF ACTIVATOR
• Selective trimming of the appliance is advised
• The trimming can be done one week after the
appliance is issued to the patient.
• Trimming is done to bring about:
–Sagittal correction
–Vertical correction
–Transverse correction
41. BIONATOR
The BIONATOR appliance is
a less bulky appliance
which was developed by
BALTERS in 1960 and it
could be worn all the time,
except during meals.
42. PHILOSOPHY OF BIONATOR
• According to Balters, "the equilibrium between the
tongue and the circum-oral muscles is responsible for
the shape of the dental arches and that the functional
space for the tongue is essential for the normal
development of the orofacial system“ –
EQUILIBRIUMTHEORY
• The principle of bionator is to enhance the normal
development of jaws and eliminate abnormal and
potentially deforming environmental factors.
• It is also used if there is any TMJ dysfunction.
45. FUNCTIONAL REGULATOR
• Function regulator appliances were developed by
Rolf Frankel
• Frankel believed that the active muscle
and tissue mass i.e., the buccinator
mechanism and the orbicularis oris
complex have a major role in the
development of skeletal and dentofacial
deformities.
46. MODE OF ACTION OF FRANKEL APPLIANCE
• Increase in transverse - sagittal correction
– By use of buccal shields and lip pads –
PERIOSTEAL PULL – Bone deposition
– Sagittal correction by the activation of
labial bow.
• Increase in vertical correction
– by allowing the lower molar to erupt
freely
• Muscle adaptation
– The form and extension of the buccal
shields and lip pads corrects the
abnormal peri-oral muscle activity.
47. TYPES OF FRANKEL APPLIANCES
• FR l - used for Class I and Class II Division 1.
–FR l A - used for Class I, moderate crowding and deep bite.
–FR l B - used for Class II Division 1 overjet less than 7mm.
–FR l C - used for Class II Division 1 overjet more than 7mm.
• FR 2 - used for Class II Division 2 and Division 1
• FR 3 - used for Class III
• FR 4 - used for cases with open bite and bimaxillary
protrusion.
50. TWIN BLOCK
• The twin block appliance was
developed by William Clark in 1977,and
it consists of an upper and lower device
with simple bite blocks that engage on
occlusal inclined planes.
• It helps in guiding the mandible
downward and forward
• With the help of favorable propioceptive
contacts of inclined planes, adaptation
of the muscles of mastication
51. ADVANTAGE OVER OTHER FUNCTIONAL
APPLIANCES
• Functional mechanism similar to natural dentition.
• Occlusal inclined planes give greater freedom of
movement in anterior and lateral excursions.
• Less interference with normal function.
• Improved appearance and function due to absence of lip,
cheek and tongue pads.
• Esthetically acceptable.
• Can be worn 24 hrs even while eating
53. AT ANGLE
90 DEGREES
Patient experienced pain and difficulty in
maintaining forward position
AT ANGLE
45 DEGREES
Blocks applied equal forward and
downward force. Angulation was a bit
shallow to keep the mandible in forward
posture.
AT ANGLE
70 DEGREES
Blocks applied more forward force and
helped in more forward growth of
mandible. Angulation was more stable
54. BITE REGISTRATION
• Exactobite / George bite gauge is designed
to record a protrusive inter-occlusal record
or bite registration in wax for construction
of twin blocks.
• An overjet upto 10mm can be corrected on
the initial activation by registering an
incisal edge to edge bite with 2mm
interincisal clearance and 3-4 mm of
interpremolar clearance.
• Bite registration is upto 70% of maximum
protrusive position
55. APPLIANCE DESIGN
• Labial bow
• Delta clasp on molars
• Expansion screw
• Bite blocks extending in
the posteriors
Upper
arch
• Three ball end clasps in
between the incisors
• Delta clasp on the
premolars
• Bite blocks covering the
premolars and canine.
Lower
arch
57. TREATMENT STAGES IN TWIN BLOCK
ACTIVE STAGE
(6-9 months)
To achieve antero-posterior
correction and correct the
vertical dimension
SUPPORT STAGE
(3-6 months)
Twin block is replaced by upper
Hawley type of appliance with
upper anterior inclined plane to
support the correction achieved in
the active stage as the posterior
teeth settle into occlusion.
