Myofunctional Appliances in orthodontics

2. intrudacion
 Are appliances that utilize natural forces of orofacial
and masticatory musculature for their action
 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

3. Classifications of functional
appliances:
1.removable functional appliance
A)removable tooth borne appliance
B)removable tissue borne appliance
2. fixed functional
appliance

4. Functional appliance types
 Orthodontic functional appliances may be active
or passive:
 Active appliances reposition the mandible so that the
condyle is forced out of the glenoid fossa and this in
turn is thought to stimulate the posterior/superior
growth of the condyle
 Passive appliances act by repositioning the
musculature associated with the mandible so that the
jaw bone itself responds by growing to the new
equilibrium position

5. Passive functional
appliances
 Frankel

6. Active functional
appliances
 Fixed active functional appliances
 Herbst

7. Active functional
appliances
 Removable active functional appliances
 Bionator

8. Active functional
appliances
 Removable active functional appliances
 Woodside activator

9. Active functional
appliances
 Removable active functional appliances
 Twin-block appliance

10. Mode of action
 Most of funtional appliances act by utilizing one
or more the following
 1.a forced mand. Posture which transmites
forces to the teeth and jwas.
 2.bite planes which produce deffrential eruption

11. Advantage of functional appliances
 1.functional appliances are effective
in vertical controll of increased over
bite
 2.can be used in mixed dention
 3.minimal chiar side adjusment

12. Disadvantage
 1.succes of functional appliances depend on
patient cooperation.
 2.there is no precise tooth movement
 3.treatment duration is often prolonged.
 4.need to faces treatment to complete
treatment

13. Duration and timing of wear
 Functional appliance treatment should be
started before the pubertal growth spurt
 This is the time when the mandible may
exhibit increased growth which may be
influenced
 Functional appliances should be worn for at
least 10-12 hours a day
 These appliances should be worn at
nighttime as this is when growth takes place

14. ACTIVATOR
 Indicaitons: In actively growing individuals with
favorable growth patterns.
-class II div I mo
-class II div II mo
-class III
-class I open bite
-class I deep bite
-as a preliminary T/t before major fixed appliance therapy to
improve skeletal jaw relations.
-for post treatment retention
-children with lack of vertical development in lower facial height.

15. Contraindications
-correction of class I cases with crowded teeth
caused by disharmony b/w tooth size & jaw size.
-in children with excess lower facial height.
-in children whose lower incisors are severely
procumbent.
-in children with nasal stenosis caused by structural
problems w/in the nose or chronic untreated allergy.
-in non-growing individuals.

16. Advantages
-uses existing growth of the jaws
-minimal oral hygiene problems
-intervals b/w appointments is long
-appoints are short,minimal adjustments required
-hence, more economical

17. Disadvantages
- requires very good patient cooperation
- cannot produce a precise detailing &
finishing of occlusion.
- may produce moderate mandibular
rotation(hence contraindicated in excess
lower facial height cases)

19. 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

21. TWIN BLOCK APPLIANCE
 The Twin Block appliance is a removable,
orthodontic functional appliance that is used
to help correct jaw alignment, particularly an
underdeveloped lower jaw.
 Developed by Dr.William J. Clarks , 1977.
 Effectively combines inclined planes with
intermaxillary & extraoral traction.

22.  The removable twin block is a tissue-born functional
appliance that is worn fulltime. It helps in the
advancement of the mandible. It is a two-piece appliance
composed of an upper and lower bite block. Orthopedic
traction can be added in cases of severe skeletal
discrepancies. This includes the use of a Concord
Facebow (or headgear) at nighttime. Upper & lower bite
blocks interlock at 70
0
angle.

23.  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.

24.  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.

25. HERBST APPLIANCE
 Fixed functional appliance developed by Emil
Herbst in early 1900’s.
 Indications:
-correction of class II MO due to retrognathic
mandible.
-can be used as anterior repositioning splint
in patients having TMJ disorders.

26.  Specific indications
-Post adolescent patients: T/t completed w/in 6-
8 months,hence possible to use the residual
growth in these patients.
-Mouth breathers
-Uncooperative patients
 2 types:
-Banded Herbst
-Bonded Herbst

28.  Advantages:
- continuous action
- T/t duration is short
- less pt cooperation needed
- can be used in pts who are at the end of their
growth
- can be used in pts with mouth breathing habit.

29.  Disadvantages:
- cause minor functional disturbances.
- increased risk of development of dual bit,with TMJ
dysfunction symptoms as a possible consequence.
- repeated breakage & loosening of appliance
occurs,esp. in lower premolar area.
- plaque accumulation & enamel decalcification can
occur
- tendency for posterior open bite.

30. JASPER JUMPER
 A relatively new flexible,fixed ,tooth borne
FA.
 Introduced by J.J.Jasper ,1980
 Actions similar to Herbst appliance but lack
rigidity.
 Basically indicated in skeletal class II mo with
max. excess & mandibular deficiency.

31. Advantages:
- produce continuous force
- does not require patient compliance
- allows greater degree of mandibular freedom than
Herbst appliance
- oral hygiene is easier to manage.

32.  The best time to start functional appliance
therapy is the late mixed dentition.
 Advantage of the pubertal growth spurt
should be taken.
 Girls & boys along with early maturers should
be assessed individually.

33.  Discomfort, as both upper & lower teeth are
joined together.
 Mainly depends on patient’s compliance
 Can be used only if a favorable horizontal growth
pattern is present in cases of Class II correction.
 It has to be removed during
masticaiton,particularly when strongest forces are
applied.
 May interfere with speech.
 Treatment duration is often long

35. Refernces
 http://cache.virtualtourist.com/3709891-
Long_neck_Karen_in_Shan_state_of_Burma-Burma.jpg
 http://farm1.static.flickr.com/47/154578698_6011a485ce.jpg
 http://www.sleepingtiger.org/blog/wp-
content/uploads/2007/08/maxyawns.jpg
 http://imagecache2.allposters.com/images/146/PP0195.jpg
 http://www.nimrodental.co.uk/appliances/media/functional5.jpg
 http://coloradospringsortho.com/Web%20site/About
%20braces_files/herbst_appliance.jpg
 http://www.weisskircher.de/bilder/bionator.jpg
 http://www.tanos.co.uk/braces/bkb/images/activatorwoodside.jpg
 http://www.orthodentlab.com/products/images/photos/TwinBlock1.
jpg

36. References
 Harrison JE, O’Brien KD, Worthington HV. Orthodontic treatment for
prominent upper front teeth in children (review). The Cochrane
Collaboration. John Wiley & Sons, 2008.
 Nguyen QV, Bezemer PD, Habets L, Prahl-Andersen B. A systematic review
of the relationship between overjet size and traumatic dental injuries.
European Journal of Orthodontics 1999;21(5):503-515.
 Pavlow SS, McGorray SP, Taylor MG, Dolce C, King GJ, Wheeler TT. Effect
of early treatment on stability of occlusion in patients with Class II
malocclusion. American Journal of Orthodontics and Dentofacial
Orthopedics 2008;133:235-244.
 Dolce C, McGorray SP, Brazeau L, King GJ, Wheeler TT. American Journal of
Orthodontics and Dentofacial Orthopedics 2007;132:481-489.
 Cozza P, Baccetti T, Franchi L, De Toffol L, McNamara JA. Mandibular
changes produced by functional appliances in Class II malocclusion: a
systematic review. American Journal of Orthodontics and Dentofacial
Orthopedics 2006;129:599.e1-599.e12.