Diagnosis and Treatment planning

Question 1

Why is correct orthodontic diagnosis important?

Answer 1

• Orthodontic appliance can move teeth very well but can modify skeletal relationship minimally
• Severe skeletal discrepancy may require surgical intervention

Question 2

What are the key factors we want to include for diagnosis?

Answer 2

• Description of malocclusion
• Determine cause of malocclusion
• Are causes dentoalveolar or skeletal
• Lateral cephalogram

Question 3

What to if anterior cross bite is dental or skeletal?

Answer 3

• Dental = orthodontics
• Skeletal = orthognathic surgery

Question 4

What are the objectives of orthodontic treatment?

Answer 4

• To produce an occlusion that is stable, functional and aesthetic
• To facilitate other forms of dentistry e.g. crowns/bridges etc

Question 5

What are the aims of treatment?

Answer 5

• Full correction of malocclusion
• Class I incisor relationship (OJ/OB normal)
• Class I canine relationship
• Class I molar relationship (can accept Class II)
• No rotations, spaces, flat occlusal planes

Question 6

What are the stages of treatment planning?

Answer 6

• Plan around lower arch (angulation of LLS is stable)
• Decide on treatment in lower
• Build upper arch around lower and aim for class I incisor and canine relationship
• Decide on molar relationship (class I or full unit class II molar relationship)

Question 7

How do you measure arch length or space available in crowded pt?

Answer 7

• A + B + C + D = arch length or space available

Question 8

How you measure the space required in crowding pt?

Answer 8

• Estimate width of all teeth anterior to first permanent molar
• 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = space required

Question 9

How do you calculate discrepancy in crowding pt?

Answer 9

• Work out space available e.g. 69mm
• Work out space required e.g. 74mm
• Discrepancy e.g. -5mm

Question 10

What is the general principles for space required in lower arch?

Answer 10

• If mild of 0-4mm discrepancy then consider non-XLA (stripping) or XLA 5’s
• If moderate of 5-8mm discrepancy then consider XLA 5’s or XLA 4’s
• If severe of 8+mm discrepancy then consider XLA 4’s

Question 11

What are the general principles for crowding if lower arch has a tooth extracted?

Answer 11

• If XLA occurred in lower arch then XLA upper arch for MR class I
• If no XLA in lower arch then either
• XLA upper arch so MR Class II
• Distalise UBS using headgear for MR class I

Question 12

How can you assess crowding?

Answer 12

• Space required and space available
• Overlap technique

Question 13

What is the overlap technique?

Answer 13

• Estimate how much the contact points of each tooth overlap with the adjacent tooth
• Add all measurements up

Question 14

Treatment plan set out?

Answer 14

• Comprehensive or compromise
• Relief of crowding (XLA)
• U/L fixed appliances to fix
• Rotations and align
• Reduce OB
• Reduce OJ
• Correct incisor, molar and canine relationship to class I
• Retain using U/L thermoplastic retainers

Question 15

What do you need to remember if all space from extractions are going to be utilised?-

Answer 15

• Need to reinforce anchorage
• Use transpalatal arch or temporary anchorage device (TADs)

Question 16

What do retainers do?

Answer 16

• Retainers needed to hold teeth in position after active movement

Question 17

What are the treatment options for a pt?

Answer 17

1. Accept malocclusion (warn pt of risks and record in notes)
2. Extractions only (not good at fixing OJ)
3. URA (really good for reducing OJ)
4. Functional appliances +/- XLA (Mainly for Class II)
5. Fixed appliances +/- XLA
6. Complex txt involving orthodontics and restorative treatment or orthodontics and orthognathic surgery

Question 18

When wil overbite reduction and functional appliance therapy work best?

Answer 18

• Rely on growth for success
• Use during adolescent growth spurt