This document provides an overview of functional orthodontic appliances. It begins by explaining that orthodontic appliances can be either removable, fixed, or functional. Functional appliances work by utilizing forces from the muscles rather than having an active component themselves. They are often removable and used to treat Class II and Class III malocclusions in growing patients. Common functional appliances discussed include lip bumpers, oral screens, twin blocks, Andresen activators, Bionators, Herbst appliances, and Frankel regulators. The document concludes by discussing considerations for choosing a functional appliance and their management.

1. Functional
Appliances
Mohanad Elsherif
BDS (U of K), MFD RCSI, MFDS RCPS(Glasg), MSc (Orthodontics), M.Orth. RCSEd
‫الرحيم‬‫الرحمن‬‫هللا‬ ‫بسم‬
Ibn Sina University
Faculty of Dentistry
Department of Orthodontics

2. Introduction
 Our teeth lies in a balanced zone where the
natural forces of the extraoral and intraoral
muscles applied to it are equal, any disturbance
or alteration of these forces will results in tooth
movement.

3. Orthodontic appliances
 Removable appliances.
 Fixed appliances.

4. Orthodontic Appliances
 Functional appliances.
 Extraoral appliances.

5. Removable appliances

6. ACTIVE COMPONENT: Z-spring to 1/

7. ACTIVATE THE Z-SPRING....

9. ...VOILA!

10. Fixed appliances

11. Extraoral appliances

12. Functional appliances
They don’t have
active components!!

13. Definition
 A group of orthodontic appliances, mostly
removable, that generally are not active by
themselves, but instead utilize forces
generated by the masticatory and facial
musculature.
Graber

14. Mechanism of Action
How do they work!!

15. How?
Spring

16. How?
Tongue Lips
Force Elimination

17. Lips
How?

18. How?
Lips
Force
Transmission

19. Mandible
Maxilla
Functional
appliance
How?
Growth
modification

20. Mandible
Maxilla
Functional
appliance
How?
Growth
modification

21. Class II and Class III functionals
 They should be able to displace
(posture) the mandible.

22. Mandible
Maxilla
Functional
appliance
Class II functionals
Skeletal effects (25%):
 Restrain forward
maxillary growth.
 Stimulate mandibular
growth.
 Forward movement of
the glenoid fossa.
 Increased lower facial
height.

23. Mandible
Maxilla
Functional
appliance
Class II functionals
Dental effects (75%):
 Retroclination of cupper
incisors.
 Proclination of the Lower
incisors.
 Reduce overjet.
 Inhibition of forward
movement of maxillary
molars.
 Mesial and vertical
movement of mandibular
molars.

24. Mandible
Maxilla
Functional
appliance
Class III functionals
Mode of action:
Opposite to class II

25. Indications
 Growing patient.
 Well motivated.
 Favorable pattern and direction of growth.
 Reduced lower facial height.
 Spaced upper incisors and crowded lower ones (in
class II malocclusion).
 Class II div 1 malocclusion mainly.

26. Contraindications
 Adults.
 Children with neuromuscular disorders: e.g.
poliomyelitis, cerebral palsy.
 Uncooperative patients.
 High angle cases (i.e. increased lower facial height).
 Unfavorable growth.
 Protruded lower incisors.
 Airway obstruction.

27. Components
 Mandibular posturing component.
 Eruption guidance components ( vertical control
components).
 Retentive (stabilizing) components.
 Passive components.
 Active components. Contemporary orthodontics
5th edition

28. Lip bumper
 Can be used for both mandible
and maxilla.
 Uses the muscular force from
upper or lower lip to provide distal
force specially to molars.
 Remove soft tissues forces from
labial aspect which result increased
lower incisor inclination by influence
of tongue.
 In other word it expand the arch in
A-P direction.
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

29. Oral Screen
 Consist of vestibular shields
which holds the lip away from all
teeth except upper incisors.
 Pressure from lips is
transferred to and acts to move
them palatally.
 Can be used in mixed dentition
to intercept thumb sucking and
mouth breathing habit.
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

30. Twin Block
 It is a 2 part appliance consist of
upper and lower removable
appliances.
 Each appliance cribs on 64/46's
and bite blocks 7mm height and 70
degree to the occlusal plane.
 Additional components:
± lower incisor capping, ±
expansion screw ± Head gear
attachments, ± labial bow.
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

31. MandPosturingcomponent
Eruptionguidancecomponent
Retentivecomponent
Passivecomponent
Activecomponent

33. Andresen Activator
 Also known as monoblock and
Norwegian appliance.
 It is a loose fit appliance that consist of
upper and lower plates appear joined
together.
 Buccal faceting to aid posterior
eruption guidance (it guide the lower
molar to erupt mesially and the uppers
to erupt distally).
 Lower incisor capping.
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

34.  Bulky and may be
intolerable.
 Difficulty in speech.
 Needs removal during
eating.
 Arch expansion cannot
be carried out
simultaneously.
Limitations
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

35. Bionator
 it is also a loose fit appliance
that consist of:
 Acrylic body, incorporates
reverse coffin to encourage a
lower tongue position.
 Reverse loop labial bow which
extends about 3-4mm from teeth
buccally.
 Lower incisor capping.
Eirew, 1981
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

36. Bionator
 Used in mixed
dentition.
 Used to bring
mandible in forward
position .
 Can be used in deep
bite or to maintaining
bite.
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

37. General rule
 Appliance name: Class II
Activator, bionator, twin block, ……
 Reversed: class III
Reversed activator, reversed bionator, reversed twin block, ……
 Modified: open bite
Modified activator, modified bionator , modified twin block, ….

38. Herbst appliance
 Herbst is a fixed functional
appliance that consist:
 Bands on upper first molars
and lower first premolars.
 Continuous telescopic arms
connecting the upper first
molars and lower first
premolars.
 Rapid correction (6 months).
Pancherz, 1979
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

39. Frankel appliance
 Also called functional regulator.
 Consist of wire framework with
lingual / buccal shields and lip
pads.
 Used in early mixed dentition.
 Fragile and can be distorted.
 Has direct effect on
neuromuscular system.
 Expands dental arches.
Frankel, 1980
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

40. Types
 FR I
Type A: Class I.
Type B: Class II div 1 overjet: <5mm.
Type C: Class II div 1 overjet: >7mm.
 FR II Class II div 2.
 FR III Class III.
 FR IV Open bite & mild
bimaxillary proclination.
Frankel, 1980
 Mand Posturing component
 Eruption guidance component
 Retentive component
 Passive component
 Active component

41. Classification
Depending on the type:
1. Removable functional appliances
2. Fixed functional appliances.

42. Classification
Depending on the mode of action:
1. 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. e.g. twin block
2. 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. e.g. Frankle

43. Classification
Depending on the relationship with the oral tissues:
1. Passive tooth borne e.g. Andresen.
2. Active tooth borne e.g. Twin block.
3. Tissue borne e.g. Frankel.
Proffit et al., 2007

44. Classification
Depending on the degree of mandibular displacement:
1. Myodynamic:
Medium mandibular opening(< 5mm), work by stimulating
muscle activity e.g. Andresen activator.
2. Myotonic:
Large mandibular opening (8-10mm), work by passive muscle
stretch e.g. Harvold appliance.
Houston et al., 1993

45. Choice
Depends on:
 Patient factors:
• Age.
• Compliance.
• Malocclusion.
 Clinician factors:
• preference I familiarity.
• laboratory facilities.

46. Management of functional
appliance
 Full records: SM, DPT, Lateral Ceph, Photos.
 Well extended upper and lower imprisons.
 Construction bite.
 The cast along with the construction bite are mounted
on the articulator.
 Use cold or heat cure to fabricate the appliance.
 Motivate the patient and the family.
 Wear gradually till reach 14 hours/day at least.

48. wear
 12-14 hours:
• Andresen.
• Harvold.
• Bionator.
 full-time:
• Twin block.
• Herbst.
• Frankel (except for eating/sports).

49. At each visit assess
 Comfort.
 Wear.
 Interferences with the eruption.
 Overjet and buccal segment relationship.
 Activation.
 Motivation.

50. Retention
 Wear the same functional appliance night time
only until growth stops or,
 Upper removable appliance with labial bow and
anterior inclined bite plane, part time wear.

51. Problems
 Compliance.
 Lower incisor proclination.
 Breakage.
 Precise detailing of tooth position not possible, so it
may require second phase of treatment.
 Biological variability.
 Relapse.

52. Declaration
 The author wish to declare that; these presentations are his original work, all
materials and pictures collection, typing and slide design has been done by the
author.
 Most of these materials has been done for undergraduate students, although
postgraduate students may find some useful basic and advanced information.
 The universities title at the front page indicate where the lecture was first
presented. The author was working as a lecturer of orthodontics at Ibn Sina
University, Sudan International University, and as a Master student in Orthodontics at
University of Khartoum.
 The author declare that all materials and photos in these presentations has been
collected from different textbooks, papers and online websites. These pictures are
presented here for education and demonstration purposes only. The author are not
attempting to plagiarize or reproduced unauthorized material, and the intellectual
properties of these photos belong to their original authors.

53. Declaration
 As the authors reviews several textbooks, papers and other references during
preparation of these materials, it was impossible to cite every textbook and journal
article, the main textbooks that has been reviewed during preparation of these
presentations were:
Contemporary Orthodontics 5th edition; Proffit, William R, Henry W. Fields, and
David M. Sarver.
Handbook of Orthodontics. 1st edition; Cobourne, Martyn T, and Andrew T. DiBiase.
Essentials of orthodontics: Diagnosis and Treatment; Robert N. Staley, Neil T. Reske
Orthodontics: Current Principles & Techniques 5th edition; Graber, Lee W, Robert L.
Vanarsdall, and Katherine W. L. Vig
Orthodontics: The Art and Science. 3rd Edition. Bhalajhi, S.I.

54. Declaration
 For the purposes of dissemination and sharing of knowledge, these
lectures were given to several colleagues and students. It were also
uploaded to SlideShare website by the author. Colleagues and students
may download, use, and modify these materials as they see fit for non-
profit purposes. The author retain the copyright of the original work.
 The author wish to thank his family, teachers, colleagues and students
for their love and support throughout his career. I also wish to express
my sincere gratitude to all orthodontic pillars for their tremendous
contribution to our specialty.
 Finally, the author welcome any advices and enquires through his
email address: Mohanad-07@hotmail.com

55. Thank you