This document provides an overview of myofunctional appliances used in orthodontics. It discusses how they work to modify skeletal discrepancies by harnessing natural muscle forces. Different types of appliances are described, including activators, Frankel regulators, and Twin Blocks. Key factors in case selection and successful treatment outcomes with these appliances are highlighted, such as patient age and cooperation. The document also reviews concepts like Moss's functional matrix theory and how appliances can guide dental changes and bone growth. Contraindications and factors maximizing success are outlined.

1. MYOFUNCTIONAL
APPLIANCES
PARMINDER
KAUR
MDS

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.

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

37. MODIFICATION OF
ACTIVATOR

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

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.

54. FIXED TWIN BLOCK

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