Growth modification appliances

Question 1

List the types of growth modification appliances

Answer 1

1. Removable
   - Headgears
2. Functional appliances:
   - Removable: Bionator/ Twin block
   - Fixed: Herbst

Question 2

Describe removable headgears, and state when they are used

Answer 2

Description
· Headgear is attached to the patient’s head with a strap or number of straps around the patient’s head or neck
· A force is transferred to the mouth / jaw(s) of the subject

When it is used:
· Used in children whose mouths/ jaws are growing

Question 3

Describe functional appliances in terms of:

• Purpose
• How it works
• How long it is worn for
• The different forms

Answer 3

Purpose:
· The most common use of a functional appliance is to encourage an underdeveloped lower jaw to move forward (class II)

How it works:
· The functional appliance holds the lower jaw forward until the teeth, jaws and joints have adapted and the desired jaw position is reached

How long it is worn for:
· Worn for 9- 12 months

The different forms:
· Can be fixed or removable

Question 4

Describe the removable functional appliance “twin block”

Answer 4

• A Twin Block appliance is made up of two removable plates that clip onto the upper and lower teeth
• Whilst being worn, the appliance will hold the jaws slightly apart and help bring the mandible forward
• The upper plate may also have an expansion function which enables widening of a narrow maxillary arch

Question 5

Describe the removable functional appliance “Bionator”

Answer 5

• Usually has only one piece worn on the palate

* Encourages the mandible to be in the correct forward position

Question 6

Explain the fixed functional appliance called Herbst, who it is used on and how long it is used for

Answer 6

Explanation:
· Causes the lower jaw to move forward and the upper molars to move backward

Used on:
· Growing people

Used for:
· Worn for 9-12 months