2. INTRODUCTION
Functional appliances are used in orthodontics to modify or
camouflage an underlying skeletal discrepancy.
Passive appliances harness natural forces of the oro-facial
musculature that are transmitted to the teeth and alveolar bone
through the medium of the appliance.
Basis of functional treatment is based on principle that a ‘new
pattern of function’ dictated by the appliance , leads to the
development of corresponding ‘new morphologic pattern’
3. Functional appliances are conceptually based
on Moss’ functional matrix theory.
Functional matrix theory proposes that
functional matrices, tissues like muscles and
glands influence skeletal units such as jaw
bones and ultimately control their growth.
4. History
W.K. Bridgam -1859, causes of irregular teeth is unbalanced
muscle pressure.
Kingsley -1880, introduced the concept of ‘jumping the bite’ in
patients with mandibular retrusion.
Pierre robin-1902, introduced monobloc, used to position the
mandible forward in patients with mandibular retrognathism
Herbst-1909, invented the first fixed functional appliances that
subjected the mandible to constant forced protrusion.
5. Alfred Paul rogers-1918, concept of ‘ myofunctional therapy’ to
the American Society of orthodontist.
William clark -1977,Twin Block appliance’. Rapid functional
correction of malocclusion transmission of favorable occlusal
forces to occlusal inclined plane that cover the posterior teeth.
6. How do they work ..
Activation of the muscles of mastication
Dental changes-
Guided eruption of teeth
Changes in incisal inclination
Tonal balance of the buccal and lingual musculature
Modification of the soft tissue activity
Bone growth
7. Potential advantages
Enlarge transverse width of arches to relieve
crowding.
Diminsh adverse fixed appliances problems
Reduced or eliminate dysfunctional habits
Treatment of temporomandibular disorders
8. Indications
Well aligned dental arches
Posterior positioned mandible
Non severe skeletal discrepancy
Lingual tipping of mandibular incisors
Proper patient selection
9. Contraindications
Class II skeletal by maxillary prognathism
Vertically directed grower
Labial tipping of lower incisors
Severe crowding
10. MAXIMIZING THE SUCCESS
OF MYOFUNCTIONAL
APPLIANCES
mild/moderate skeletal problems
Patient and family cooporation
Patient actively growing
Growth spurt for boys(12-14)
for girls(11-13)
11. CASE SELECTION
Suited to treat Class II, division 1 malocclusion-
Age : growing patient (b/w 10 yrs & pubertal growth
phase).
Social considerations: Results with minimum
supervision. Patients who live far away from clinic may
benefit from these appliances.
Dental considerations: Only the case devoid of gross
local irregularities like rotations and crowding.
Low angle cases – respond well
12. High angle cases with Increased overbite are successfully
treated
High angle cases with an open bite pose special problems
Class II , div 2 is usually first modified to a div 1 and then
treated.
Mild class III malocclusions, which present with a reverse
overjet can also be considered.
13. CEPHALOMETRIC ANALYSIS
This includes three angular
measurements
Saddle angle
Articular angle
Gonial angle
And four linear measurements
-anterior and posterior facial height.
-anterior and posterior cranial base length.
14. Saddle Angle N-S-Ar
A large saddle angle signifies posterior
condylar position and a mandible which
is posteriorly placed with respect to
cranial base and maxilla.
Posterior positioning of the fossa is
some times compensated by the
articular angle and ramal length.
A non compensated posterior
positioning of mandible caused by a
large saddle angle is difficult to influence
with functional therapy.
15. Articular angle S-Ar-Go
A decrease in the articular angle
can be seen in
- Anterior positioning of the
mandible
-Mesial migration of posterior
segment
An increase in the articular angle is
seen in:
-Posterior relocation of mandible
-Distal driving of posterior teeth.
16. Gonial angle AR-Go-Me
An angle formed by tangents to the
body of the mandible and posterior
body of the ramus.
Acute or small angle ,signifies the
horizontal growth direction.
condition favorable for functional
appliance therapy/anterior positioning
of mandible
17. Anterior and Posterior facial
height
These are linear metric measurements
-Anterior facial
height—nasion to
menton
-Posterior facial height—
sella to gonion
18. Jarabak’s Ratio
It gives an idea about the growth direction of the patient.
Jarabak’s ratio = PFH
----- X 100
AFH
<62% indicates vertical growth pattern.
> 65% indicates more horizontal pattern of growth
19. Visual Treatment Objective
Important diagnostic test undertaken before making a decision
to use a functional appliances.
Performed by asking the patient to bring the mandible forward
An improvement in profile is considered a positive indication for
the use of functional appliances
20. Classification- Based on
transmission of force
Group I appliance - transmit muscle force directly to
the teeth. e.g. inclined plane, oral screen.
Group II appliance - reposition the mandible
downward and forward (except in class III
malocclusion), activating the attached and associated
vasculature. e.g. Activator.
Group III appliance - bring mandibular changes
through musculature only. Their major operating area
is in the vestibule outside the dental arches.
Supporting bone and teeth are influenced by
changing the muscle balance through cheek shields
and lip pads. e.g. Frankel FR.
21. By Proffit-
Tooth borne active appliances: modifications of activator and
bionator designs that include expansion screws or springs to
move teeth. e.g. Expansion activator, Orthopaedic corrector.
Tooth borne passive appliances. These appliances have no
intrinsic force generating capacity from springs or screws
and depend only on soft tissue stretch and usual activity to
produce treatment effects e.g. activator, bionater.
Tissue borne appliance. The appliance has minimal contact
with teeth and is located in vestibule. e.g. Functional
regulator.
22. Myotonic Appliance -These appliance depend on
muscle mass for their action.
Myodynamic appliances -These appliances depend
on muscle activity for their action.
Removable Functional Appliances - can be removed
and inserted into mouth by patient.
Fixed functional appliances - cannot be removed by
the patient
23. Treatment Principles
Force application : Primary alteration in form with a secondary
adaptation in function.
Force elimination : Elimination of abnormal and restrictive
environmental influences on the dentition.
24. Functional component
Bite Planes
Shields Or Screens
Construction Or Working Bite
BITE PLANES
Flat or Inclined
Anterior or Posterior
Contacting Single or Multiple Teeth
25. FLAT ANTERIOR BITE PLANE-
It should be of sufficient dimensions to disocclude the
posterior teeth .
Following effects are seen:-
Differential eruption of posterior teeth.
Non eruption, relative or absolute intrusion of incisors.
Incisor overbite reduction
Dis-occlusion with removal of intercuspation may will
be responsible for any additional increments of
mandibular growth.
Unimpeded posterior tooth eruption may result in a
downward and backward mandibular rotation that tends
to increase anterior vertical lower height and reduces
the prognathism of the mandible.
26. FUNCTIONAL APPLIANCES
ADVANTAGES:-
Elimination of abnormal
muscle function.
Treatment can be initiated at
early age.
Psychological disturbances
avoided.
Less chair side time.
Frequency of patient visit is
reduced.
Worn during night so good
patient acceptance .
LIMITATIONS-
Cannot be used in adult
patients.
Cannot be used to bring
about individual tooth
movement.
Patient cooperation is
required.
Pre-functional orthodontic
tooth movement is
required.
Fixed appliance therapy
may be required.
27. Vestibular Screen
Takes form of a curved shield of acrylic
placed in the labial vestibule.
Introduced by Newell in 1912.
Principle: Both force application and
elimination.
Indications :
Habits interception.
Mild distocclusions.
To perform muscle exercises.
To correct mild anterior proclination
28. MANAGEMENT AND MODIFICATIONS
To be worn during night and 2-3 hours
during daytime.
Patient is instructed to maintain lip seal.
Modifications include :
Hotz modification
Double oral screen
Kraus’s modification.
29.
30. Lip Bumper
MODE OF ACTION
Holding the muscles and soft tissue away
from the teeth
Shields are placed up to 3 mm away from
the teeth
EFFECTS
By reducing the pressure of the lips and
cheeks on the teeth, the tongue applies an
uncompensated lingual force on the teeth
resulting in distal molar crown tipping, slight
expansion of the buccal segments, and
incisor proclination.
31. Activator
INDICATIONS
Class II, div 1
Class II, div 2
Class III malocclusion
Class I open bite
Class I deep bite.
CONTRA INDICATIONS
Class I problems of crowded
teeth.
Excessive lower facial height
In non growing individuals.
32. MECHANISM OF ACTION
Stretching of
elevator muscles of
mastication which
starts contracting
Myotactic reflex
Kinetic energy
produced
Prevent maxillary
growth
Moves maxilla
distally
Reciprocal forward
force on mandible
33. CONSTRUCTION BITE
Bite opening - 2-3 mm
advancement - 4-5 mm.
Overjet is too large, forward
positioning is done - 2-3 stages
In case of forward positioning
of the mandible by 7-8 mm, the
vertical opening should be
slight to moderate i.e. 2-4 mm.
If the forward positioning is not
more than 3-5 mm then the
vertical opening can be 4-6
mm.
34. FABRICATION OF
ACTIVATOR
Impression making
Study & working models preparation
Bite registration
Articulation of the model
Preparation of wire elements
Fabrication of the acrylic portion
3 parts:
Maxillary part
Mandibular part
Inter occlusal part
35. Management
Wear time:
2-3 hours a day during first week.
Second week 3 hrs during day and during sleeping.
Trimming plan is developed on the basis of individual needs
of the patient.
In expansion treatment the jackscrew are normally activated
by the patients at 1-week interval. Check the screw
Recall every 6 weeks
36. Trimming
Vertical control
For dolichofacial patients: intrude molars, extrude
incisors
For brachifacial patients: intrude incisors, extrude
molars
38. BIONATOR
Developed by Balters in 1950’s.
Modified activator
less bulky & more Elastic
3 types-
Standard type-class II div I having narrow
dental arches
Class III Appliance
Open bite appliance
39.
40. FRANKEL FUNCTIONAL
REGULATOR
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.
41. TYPES OF FUNCTIONAL
REGULATOR
1. FR l-used for Class I and
Class II, Division 1.
FR la -used for Class I ,moderate crowding and deep bite.
FR lB -used for Class II Division 1 overjet less than7mm.
FR lc -used for Class II Division 1 overjet more than7mm
2. FR Il-used for Class II Division 2 and Division 1
3. FR Ill-used for Class III
4. FR IV-used for cases with open bite and bimaxillary
protrusion.
5. FR V-FR with headgear.
42. FRANKEL REGULATOR-II
Promotes transverse and vertical
development of maxillary and
mandibular arches,
corrects Class II, Division 2 cases and
opens bite. Used after the maxillary
incisors have been slightly proclinated
by an upper removable appliances
43. TREATMENT TIMING
late mixed and transitional dentition period, when
both the soft and hard tissues are undergoing their
greatest transitional changes.
Treatment for Class III and open bite cases should
usually start sooner than for Class Il problems.
44. MODE OF ACTION OF FR-II
1. Increase in transverse sagittal direction by
use of buccal shields and lip pads.
2. Increase in vertical direction
by allowing the lower molar to erupt freely
because appliance is fixed to the upper
arch.
3. Muscle adaptation
The form and extension of the buccal shields
and lip pads along with the prescribed
excercises corrects the abnormal peri-oral
muscle activity.
45. ORAL EXERCISES WITH
FRANKEL
Frankel-full time wear appliance.
Lips to be closed at all times or keep a paper
between the lips.
Swallowing, speaking, etc. with the appliance in
mouth, itself serves as an exercise.
46. WEAR TIME
First few weeks: 2-4 hours/day (day time)
After 3 weeks : 4-6 hours/day (day time)
After 3rd visit (2 months) : full time wear.
The patient is asked to perform oral gymnastics i.e.
talking , reading, tightly grasping the appliance in the
vestibule
47. TWIN BLOCK
Used to help correct jaw alignment, particularly
an underdeveloped lower jaw.
Dr.William J. Clarks , 1977.
Consists of u/l plates having occlusally inclined
planes that induce favorably directed occlusal
forces by causing a functional mandibular
displacement.
48. MODE OF ACTION
Twin blocks are simple bite blocks
designed for full time wear.
Upper and lower bite blocks interlock at a
70 degree angle.
Twin blocks achieve rapid functional
correction of malocclusion by modifying
the occlusal inclined plane,guiding the
mandible forward into correct occlusion.
The forces of occlusion are used to correct
the malocclusion.
49. MUSCLE RESPONSE
Changes in the muscles activity (1-7
days)
Decreased in activity of
temporalis muscles increased
activity of masseter and
lateral pterygoid (3 weeks)
cycles of changes was
completed (3 months)
50. PHASES OF TREATMENT
Active phase -Average time of treatment 6-9 months to
achieve full reduction of overjet to a normal incisors
relationship and to correct the distal occlusion.
Support phase -3 to 6 months for molars to erupt into
occlusion and premolars to erupt after trimming the
blocks. The objective is to support the corrected
mandibular translation while buccal teeth settle into
occlusion .
Retention- 9 months , reducing appliance wear when
the position is stabilized. An average estimate of
treatment time is 18 months, including retention.
51. TWIN BLOCK SAGITTAL
APPLIANCE
Used to treat class II div 2
malocclusion.
Sagittal arch development is
necessary to increase arch length
and to advanced retroclined
incisors.
52. REVERSE TWIN BLOCK
Correction of class III malocclusion
By reversing the occlusal inclined
planes to apply a forward
component of force to the upper
arch and a downward and
backward force to lower arch.
53. MAGNETIC TWIN BLOCKS
Magnets are incorporated in
occlusal inclined plane.
Purpose of magnets is to
increased occlusal contacts on the
bite blocks to maximize the
favorable functional forces
applied to correct the
malooclusion.
55. Advantages
very good patient acceptance.
bite planes offer greater freedom of movement
& lateral excursion.
less interference with normal function.
significant changes in patient’s appearance within 2-3
months.
56. HERBEST APPLIANCES
JASPER JUMPER
THE MANDIBULAR
ANTERIOR
REPOSITIONING APPLIANCE
(MARA)
EUREKA SPRING
SABBAGH UNIVERSAL
SPRING
FIXED
FUNCTIONAL
APPLIANCES
57. HERBEST APPLIANCE
Indications
1- dental CII
2- skeletal CII due to mandibular
deficiency
3- deep bite with retroclined
mandibular incisors.
Contra indication
1-Open bite
2-vertical grower
Disadvantages
• Appliance is prone to breakage.
• Lateral movement is restricted
58. JASPER JUMPER
Indications
• Dental Class II malocclusion
• Deep bite with retroclined
mandibular incisors.
Contraindications
• Dental and skeletal open
bites.
• Minimum buccal vestibular
space.
• Vertical growth pattern with
increased lower facial height.
-Cases prone to root resorption
59. JASPER JUMPER
Advantages
- Ease of insertion and
activation
- Generation of intrusive forces
on molars and incisors.
Disadvantages
- Frequent breakages
- Compromised oral hygiene
- Externally bulge in the cheeks
60. MANDIBULAR ANTERIOR
POSITIONING APPLIANCES
(MARA)
Indication
-Skeletal Class II with
mandibular deficiency.
Contraindications
-Cases prone to root
resorption Dental and
skeletal open bite
-Vertical growth pattern.
61. EUREKA SPRING
Advantages
- Good patient acceptance
- Can be used for Class Il and
Class ill
- Components are available
separately
- Significantly less expensive
Disadvantages
-Technique sensitive insertion
procedure
- Frequent breakages of interval
spring
62. SABBAGH UNIVERSAL
SPRING
It is the latest inter arch compressive
spring to be introduced and has a
number of unique features .
• Available in one standard link.
- No difference in appliance for
the right and left sides.
- Lateral mandibular movement
possible.
- More resistant to fatigue fracture
63. SABBAGH UNIVERSAL
SPRING
The SUS is a combination
between the Herbst appliance
(as a telescope) and the Jasper
Jumper (as a spring) aiming to
increase the efficacy of th
treatment and to minimize
their disadvantages.
INDICATIONS-
•Class II, late growth cases
(rapid class II correction )
•Non-compliant class II
patients
•TMD therapy
64. SABBAGH UNIVERSAL
SPRING
ADVANTAGES
Dentoalveolar changes:-
- distal movement of
the upper molars
- mesial movement of
the lower molars
- retrusion of the upper
incisors
- protrusion of the lower
incisors
DISADVANTAGES
- Unsuitability for Class Ill
treatment
- Limitations in patients
with maximum opening
of less than 48 mm.
- Increased force levels
- Considerably greater cost
65. CONCLUSION
The method chosen depends upon on a series of factors that
must be carefully evaluated before the therapy is instituted.
The developmental age of the patient
Location and etiology of malocclusion
The specific morphological characteristics in both skeletal and
dental arches
The motivation and likely continuing co-operation of both the
patient and the patient’s parents.
No universal appliance or formula is available for any
malocclusion.
Only a careful diagnosis, a continuing diagnostic monitoring
during treatment, a number of appliances in the armamentarium,
and a willingness to change appliances as changing situations
dictate will ensure the best possible treatment
Notes de l'éditeur
-they can bring about dentoalveolar changes in the saggital, transverse-by shielding the buccal muscles force away from dental arch and vertical direction. They can be designed to allow the selective eruption of teeth
MFA are capable of accelerating the growth in the condylar region. Bring about the remodeling in the condylar region.
CA Should be done before selecting the case for the any functional therapy
If articular angle is large the mandible is retrognathic and small if mandible is prognathic
The measurement should be done with teeth in habitual position
Ratio of PFH/AFH was described by jarabak in 1972 and is known as Jarabak’s ratio.
FA- COMPRESSIVE stress and strain act on the structures involved and result in a
FE- all the functional appliances are assemblies of a few simple components
INCLINED PLANES: May be designed to provide labiolingual mechanical eruptive displacement of incisors or the buccolingual deflection of the erupting posterior teeth.
Hotz modification-oral screen can be fabricated with metal ring projecting b/w upper and lower lip .help in exercise.
Tongue thrust habit-a additional screen is placed on the lingual aspect of the teeth. In mouth breather – the vestibular screen should be fabricated with the no. of holes that are gradually closed in phased manner.
Lip bumpers gain intraarch space by removing the pressure of the buccal musculature permitting lateral and anterior dentoalveolar development.
Andresen121 inDenmark in 1908
Intermaxillary wax record used to relate the mandible to the maxilla
This is done to improve the skeletal inter-jaw relationship.
Selective trimming of the activator can be done to intrude and extrude the teeth
BOW activator-is a horizontally split activator having maxi and mandibular portion connected together by an elastic bow.this kind of modification allow the step wise saggital movement by the adjustment of bow. WUNDERER modification-that is mostly used in treatment of class3 malocclusion ..maxi and mandi portion connected by the screw,by opening the screw the maxi portion move anteriorly,reciprocal backward movement of the mandible.
bulkiness of the activator and it limitation to night-time wear was a major deterrent in its greater use by clinicians to obtain maximum potential functional growth guidance. Standard type-consist slender acrylic body fitted to the lingual aspect of mandi and portion of the maxi .anterior region may uncovered. Wire component- palatal arch and vestibular bow
Class iii – acrylic part similar to standard type .used in mandi prognathism .palatal arch is placed in opposite direction.
Open bite-wire component are same .the maxi acrylic portion is modified so that anterior area is covered .its purpose is prevent tongue thrusting b/w the teeth as tongue is responsible for most cases of open bite
Hence he developed function regulators as orthopedic exercise devices, to aid in the maturation, training and
reprogramming of the orofacial neuromuscular system.
Removable orthodontic functional appliance that is
Initial placement of appliance produced an increase in the over all activity of the muscle respone.
This level of activity persist for 4-weeks.
Design- the upper TB is modified by the incorporation of two screws set in the palate for anteroposterior arch development.
- In lower arch a screws may be used in canine and premolar region
This is the most effective appliance for arch development to treat more severe labial and lingual crowding.
Design is similar to saggital TB with reverse inclined plane.
Magnets should be used only ,where speed of the treatment is important consideration.
The fixed twin block is similar to the removable twin block, but can be used in non-compliant
patients. It is similar in design to the Herbst appliance, however the telescopic tubes of the
Herbst appliance are replaced with two bite blocks.
(non compliance) Success of orthodontic treatment often relies on the patient’s cooperation in the wearing of removable appliances .
Eliminating the need to use these places the treatment result more under the control of orthodontist. This lead to development of fixed appliances
(non compliance)
HA-MAKE A artificial joint working between the maxilla and mandible . Keeps the mandibular in continous anterior positioned the tube is fixed to the distal end of the maxillary molar while the rod is fixed to the lower ist premolar
Jasper module is similar to the tube and plunger of of herbest appliance .but is more flexible.the jasper module available in size 26mm to 38mm.the force module is selected by measuring the distance between mesial aspect of the upper face bow tube and distal to mandibular canine.when the teeth comes into occlusion ,the forced module becomes longer and producing mesial force on mandibular arch and distal force on maxi arch
One of the first inter arch appliances to utilize the compressive forces.
• - Slotted screw for partial adjustment of distal aspect of the plunger assembly (upto 4 mm) The second coil spring
inserted at the time of placement which in combination with the internal spring permits a greater active
extension of force than any other
appliance.
rotation of the occlusion plane in clockwise
direction.
A number of methods are available to attempt the correction of malocclusions.