Functional appliances

Question 1

What is a functional appliance?

Answer 1

Fixed or removable
Achieves forward posture of mandible
Produces combination of dental and skeletal changes
70% dento-alveolar
30% skeletal

Question 2

What is the ideal timing of treatment?

Answer 2

Girls 10-12 years

Boys 14-16 years

Question 3

What are two functional appliances that could treat a class III patient?

Answer 3

Reverse clark’s twin block
Frankel regulator
Both are rarely done nowadays

Question 4

What are the indications for class II functional treatment?

Answer 4

Mild to moderate skeletal II case
Increased overjet
Reduced lower anterior facial height or average LAFH
Proclined maxillary incisors
Retroclined mandibular incisors
Actively growing patient
Class II molars/canines

Question 5

What is the mode of action of a functional?

Answer 5

Dento-alveolar changes - retroclined maxillary incisors, proclined mandibular incisors, distal movement of upper dentition, mesial movement of lower dentition

Increase in mandibular length - downward and forward translation of condyle, encouraging compensatory backward growth of condyle

Increased LAFH - passive molar eruption

Forward remodeling of the glenoid fossa

Maxillary restraint - especially with use of headgear or class II traction forces

Question 6

List the types of functional applainces

Answer 6

Tissue borne
Tooth borne
Removable
Fixed

Question 7

List some removable functional applainces

Answer 7

Twin block
Andresen
Bionator
Bass
Frankel

Question 8

What are two types of fixed functional appliances?

Answer 8

Herbst

COFF

Question 9

What does a twinblock consist of?

Answer 9

Base plate
Bite block
Adams cribs 0.7MM
Ball clasps 0.7MM
Labial Bow 0.7MM

Question 10

How do you know if a patient has been wearing their twin block appliance?

Answer 10

Posterior lateral openbites may occur
Patient will be able to insert and remove with ease
Patient should be able speak with them in
Salivation should be controlled

Question 11

Advantages and disadvantages of a twin block?

Answer 11

Adv - When worn full time, appliance should work within 6-9 months
Can be integrated with fixed appliances
Easy to adjust and reactivate
Easy to speak and eat with once the patient is used to appliance
Short chairside appointments

Dis - Relies on compliance
can be hard to get used to
can fracture easily when dropped or not stored properly
requires multiple appointments for construction

Question 12

What should you check in review appointments for a twin block?

Answer 12

Encourage the patient to speak with the appliance in
Does the appliance show signs of being worn
Measure overjet, eventually should be 0mm
Check molar relationship, eventually should be class III
Check fit and adjust if required
Reactivate if necessary