Class III

Question 1

How common is a class III malocclusion?

Answer 1

3% incidence

Question 2

What are the dental features of class III?

Answer 2

UPPER

• Crowded arch
• Proclined incisors

LOWER

• Aligned/ spaced arch
• Retroclined lowers
• OJ = reverse
• OB = reduced, AOB
• Crossbite = bilateral (retrusive max sits on widest part of mandible)
• Displacement on closing

Question 3

What is the growth status of a patient with a developing class III malocclusion?

Answer 3

Unfavourably (only gets worse)

Question 4

What may indicate a class III malocclusion?

Answer 4

Strong genetic link

Question 5

What is the need to treat class III?

Answer 5

1. AESTHETICS
2. DENTAL HEALTH (attrition, gingival recession, mand displacement)
3. Function (speech, mast)

Question 6

What are the treatment options for class III?

Answer 6

1. Accept and monitor (mild cases)
2. Interceptive = early URA
3. Growth mod = functional app (reverse twin block, Frankell III, protraction headgear)
4. Fixed appliances = camouflage (accept skeletal discrep, aim for incisal class I)
5. Orthognathic surgery

Question 7

What features of the malocclusion is favourable for camouflage?

Answer 7

1. Growth stopped
2. Mild-mod skeletal class
3. Ave/ increased OB
4. Can reach edge to edge
5. Little/ no dento-alveolar compensation