Diagnosis and Treatment Planning

Question 1

What are the general principles of orthodontic tx planning and diagnosis?

Answer 1

History
Examination
Differential diagnosis - list of probables
Special tests
Diagnosis
Tx plan
Treatment
Outcome

Question 2

What should be included in an orthodontic diagnosis?

Answer 2

Description of the malocclusion/incisor relationship
Determine the cause of the malocclusion
Are the causes dentoalveolar or skeletal?

Question 3

Why is a correct orthodontic diagnosis important?

Answer 3

Orthodontic appliances can move teeth well, but can modify skeletal relationship minimally
A severe skeletal discrepancy may require surgical intervention

Question 4

How are dental and skeletal anterior cross bites treated?

Answer 4

Dental - orthodontics
Skeletal - orthognathic surgery

Question 5

What are the objectives of orthodontic treatment?

Answer 5

To produce an occlusion which is stable, functional and aesthetic
To facilitate other forms of dentistry - crowns bridges etc

Question 6

What should be included in a tx plan?

Answer 6

Aims of treatment
Treatment plan in stages

Question 7

What are the aims of fully correcting a malocclusion?

Answer 7

Class I incisor relationship - OJ/OB normal
Class I canine relationship
Class I molar relationship - can accept class II
No rotations, spaces, flat occlusal plane (Andrew’s six keys)

Question 8

What are the aims of compromising treatment?

Answer 8

Correct certain aspects while accepting others
May have to work with adverse skeletal pattern and leave residual OJ especially in adults

Question 9

What are the stages of tx planning?

Answer 9

1. Plan around the lower arch
2. Decide on tx in lower (ext/nonext)
3. Build upper arch around lower, aim for class I incisor and canine relationship, OJ/OB normal
4. Decide on molar relationship - class I or full unit class II molar relationship

Question 10

What should be examined in the lower arch?

Answer 10

Crowding
Angulation of incisors to the mandibular plane
Angulation of canines
Centrelines
Curve of Spee

Question 11

What should be examined in the upper arch?

Answer 11

Crowding
Angulation of incisors to the maxillary plane
Angulation of the canines
Centrelines

Question 12

What should be examined when teeth are in occlusion (ICP)?

Answer 12

Incisor relationship
OJ
OB (curve of Spee)
Centrelines
Canine relationship
Molar relationship

Question 13

How should crowding be assessed?

Answer 13

Do you need to extract teeth?
Measure space available and space required
or
Overlap technique

Question 14

How can you estimate how much space is available and required for extraction?

Answer 14

Divide the arch length into A, B, C and D
Add these values to get the space available
Measure the 10 teeth to get the space required

Question 15

Describe the overlap technique?

Answer 15

Measure how much each teeth overlap and add the values to get the discrepancy of space?

Question 16

What are the options for mild crowding (0-4mm) in the lower arch?

Answer 16

Non extraction - stripping
Extract 5s

Question 17

What are the options for moderate crowding (5-8mm) in the lower arch?

Answer 17

Extract 5s
Extract 4s

Question 18

What are the options for severe crowding (8+mm) in the lower arch?

Answer 18

Extract 4s

Question 19

What happens in the upper arch if you have extracted teeth in the lower arch?

Answer 19

Extract the same teeth in the upper tooth

Question 20

What happens in the upper arch if you have not extracted teeth in the lower arch?

Answer 20

Extract in the upper arch if MR class II
Distalise UBS using headgear (MR class I)

Question 21

What should be written in a tx plan?

Answer 21

Diagnosis
Problem list
Tx plan
List successive stages stating tooth movements to be carried out and appliances to be used
Estimate length of treatment
If not possible to give a detailed plan, indicate when it will be reviewed - ie following eruption of teeth

Question 22

What are the tx options?

Answer 22

1. Accept malocclusion
2. Extractions only - class I crowding cases
3. URA
4. Functional appliances - class II
5. Fixed appliances
6. Complex tx involving ortho and restorative tx or ortho and orthognathic surgery

3-5 can be with or without extractions

Question 23

What are the limitations of orthodontic tx?

Answer 23

Effects are almost purely dento-alveolar and tooth movement with little effect on skeletal pattern
Tooth movements are limited by the shape and size of the alveolar processes
Teeth will only remain stable in a position where there is equilibrium between the forces of the soft tissues, the occlusion and the periodontal structures