Functional Appliances

Question 1

When are functional appliances used?

Answer 1

Used in class II skeletal cases

Question 2

How do functional appliances work?

Answer 2

1. Change position of mandible - open and forwards
2. Stretch muscles - apply force to bone and teeth
3. Use growth

Question 3

When should functional appliances be used?

Answer 3

During active growth - depend on stage of development
Dental - late mixed/ permanent mention
Emotional - motivation
Physical - height

Question 4

What forces are used?

Answer 4

Functional forces applied to teeth and bone - condyle out of glenoid fossa

Question 5

3 questions when thinking about using FA?

Answer 5

1. Who - pt selection
2. When - timing tx
3. Which one - choice FA

Question 6

What pt are ideal for this tx?

Answer 6

IDEAL: Class II div I w/ increased OJ
Class II div II - convert to class II div I THEN use FA
Class II molars
Actively growing

Question 7

Aetiology of class II?

Answer 7

14% maxillary protrusion

86% mandibular retrusion

Question 8

How to assess skeletal pattern?

Answer 8

Ceph analysis

Clinical examination: pt sitting upright and look at profile

Question 9

When to avoid FA?

Answer 9

Non-motivated pt
Class I molar relationship - could cause class III
High FMPA - increased lower face height

Question 10

How to measure standing height?

Answer 10

Height curve - take standing height = skeletal growth

Velocity curve - rate of growth per year

Question 11

When does rapid growth occur for boys and girls?

Answer 11

Boys - 11-13

Girls - 10-12

Question 12

What are the different types of FA?

Answer 12

1. Twin block
2. Activators
3. Frankel

Question 13

Give examples of activators?

Answer 13

MOA - medium opening activators
Andresen
Harvold
Bionator

Question 14

Adv twin block appliance?

Answer 14

Aesthetic
Pt can move the mandible
Full time wear
Robust
Can expand upper arch
Integrate w/ FA - at same time or following twin block

Question 15

Explain MOA?

Answer 15

Type of activator
Can help correct increased OB
Lower posterior teeth free to erupt - eruption forwards help correct class II molar relationship

Question 16

How does Andresen appliance work?

Answer 16

Type of activator

Mandible postured forwards into occlusion

Question 17

How does Frankle appliance work?

Answer 17

Soft tissue borne

Shields alter the soft tissue balance

Question 18

What is a Herbst appliance?

Answer 18

Fixed functional appliance
Piston arrangement - forces mandible forwards
Disadv: tend to break

Question 19

What are 2 modes of action of FA?

Answer 19

1. Dental

2. Skeletal inc. soft tissue/muscles

Question 20

What are dental effects of FA?

Answer 20

1. Upper labial segment retrocline
2. Lower labial segment proclines
3. Controlled eruption of lowers into class I

Question 21

What are skeletal effects of FA?

Answer 21

1. Inhibit normal forward growth of maxilla

2. Forward movement of mandible