Functional Appliances

Question 0

With regards to occlusal changes with the use of myotonic functional appliacnes, what factors contribute to this?

Answer 0

1) Mandibular growth
2) Maxillary restriction
3) Tooth movement from orthodontic forces and guided eruption

Question 1

What are the types of functional appliances?

Answer 1

1) Myotonic (Harold activator, Batters bionator)
2) Myodynamic
3) Hybrids (e.g. Clark twin block)

Question 2

How do myodynamic functional appliances work?

Answer 2

They try to harness muscle forces withhout direct action on the teeth.
Mandibular positioning and facial muscle exercises (e.ghg. lip seal) are important
These appliances are more like exercise devices

Question 3

What are the occlusal changes due to a mmyodynamic functional appliance due to?

Answer 3

1) Mandibular growth
2) Maxillary restriction
3) Periosteal stretching
4) Shielding the dentition from lip and cheek pressure

Question 4

How do hybrid functional appliances work?

Answer 4

They have features of both myofunctional and myotonic appliances.
Many are cemented to teeth to encourage patient compliance
They basically make the patient adopt a forward bite

Question 5

What are the occlusal changes from a hybrid functional appliance due to?

Answer 5

1) Mandibular growth
2) Maxillary restriction
3) Tooth movements with better results due to better patient cooperation

Question 6

How do myotonic functional appliances work?

Answer 6

• Aim to harness the muscle stretch reflexes and visco-elastic properties. These are produces via the horizontal and vertical changes in mandibular position.

Question 7

What are the effects of using a functional appliance?

Answer 7

1) Dento-alveolar - Guided toothh eruption and orthodontic side effects (incisors and upper buccal teeth held while loower buccal teeth erupt)
2) Restriction of forward mid-face growth
3) Stimulation of condylar growth
4) POsteriorly directed condylar growht vector
5) Defection of ramal form
6) Acceleration of horizontal mandibular growth vector
7) Alterred neuro-muscolar activity and function
8) relocation of glenoid fossa downwards and forwards

Question 8

What kind of cases can be treated using a fiucntional appliace?

Answer 8

1) Deep overbite
2) Increased overjet
3) Angle class II canines and molars
4) Protrusive upper incisors
5) Retruded lower incisors
6) Reeduced lower facial height
7) Good compliance

patient should be undergoing growth spurt (11-13 yrs)