Functional Appliances

Question 1

What is the ideal timing of functional treatment?

Answer 1

• girls - 12 +/- 2 years

* boys - 14 +/- 2 years

Question 2

What percentage effect does the functional have?

Answer 2

• 70% dento-alveolar

* 30% skeletal

Question 3

What functional can be used to treat class III cases?

Answer 3

• reverse Clark’s twin block

* frankel regulator 3

Question 4

Why might treatment with a functional appliance fail?

Answer 4

• poor patient compliance
• appliance not active
• patient not growing

Question 5

Three months after fit of a functional appliance, how will you know that the appliance is being worn?

Answer 5

• patient wearing appliance on arrival
• no lisp or exaggerated saliva
• indentation of appliance on palate
• appliance is loose
• lateral posterior open bite forming
• easy removal and placement
• appliance looks worn
• mild erythema on palate
• reduction in overjet and overbite
• improvement in molar relationship

Question 6

What are the clinical effects of a functional appliance?

Answer 6

• retroclination of upper incisors
• proclination of lower incisors
• postures mandible forward
• stretches the musculature
• forces transmitted to teeth and alveolar bones
• distal movement of upper molars
• mesial movement of lower molars
• lateral posterior open bite
• molar relationship change
• differential tooth eruption

Question 7

What is the angle on a twin block?

Answer 7

70%

Question 8

What can be used to assist taking a postured bite?

Answer 8

Projet fork

Question 9

What are advantages of a twin block appliance?

Answer 9

• relatively well tolerated
• robust and easy to repair
• fairly easy to advance
• expansion can be incorporated
• suitable for mixed to permanent dentition

Question 10

What are the disadvantages of a twin block appliance?

Answer 10

• retention of lower can be difficult

* relies on patient compliance

Question 11

What are solutions to a lateral open bite that forms during twin block wear?

Answer 11

• trimming the blocks
• period of night time only wear
• URA with very steep anterior bite plane - keeps mandible postured forward
• subsequent fixed appliances

Question 12

How does a functional appliance achieve its effects?

Answer 12

Forces from masticatory and facial muscles

Question 13

What is the overjet and molar relationship aim for functional appliances?

Answer 13

0-2 mm overjet
Class III molar relationship
Class III incisor relationship
Class III canine relationship

Question 14

What removable functional appliances are there?

Answer 14

• Clark’s twin block
• Andresen
• Harvold
• Frankel
• Dynamax
• Bionator

Question 15

What fixed functional appliances are there?

Answer 15

• twin block
• herbst
• advancsync

Question 16

What types of bite need to be taken for functional appliances?

Answer 16

• normal wax bite in centric occlusion

* postured wax bite

Question 17

What should be recorded at every visit with a functional appliance?

Answer 17

• overjet

* buccal segment relationship (molar relationship)