Orthodontic Treatment Planning

Question 1

What are the two components of an orthodontic diagnosis ?

Answer 1

Description of malocclusion i.e. Class II div I incisor relationship.
Cause of malocclusion i.e.
- Spacing due to small teeth.
- Early loss of deciduous teeth causing crowding.
- Digit sucking causing proclamation and increased OJ.

INCLUDE WHETHER THE MALOCCLUSION IS DENTAL OR SKELETAL ?

Question 2

For what orthodontic malocclusions should a lateral cephalogram be taken ?

Answer 2

AP skeletal problem.
Vertical skeletal problem.
Class III incisors.

Question 3

What are the 3 objectives of orthodontic treatment ?

Answer 3

To produce an occlusion which is stable, functional and aesthetic which can facilitate other forms of dentistry i.e. crowns, bridges etc.

Question 4

What are factors which might affect treatment planning for orthodontic treatment ?

Answer 4

Patient wishes.
Access to treatment.
Compliance.
Space requirements - XLA.
Aims of treatment.
Prognosis for individual teeth.
Future growth changes.
Treatment of aetiology of malocclusion.
Patient’s soft tissue profile.
Retention.
Stability.

Question 5

Define a full correction of malocclusion.

Answer 5

Class I incisor relationship with normal OJ/OB.
Class I canine relationship.
Class I molar relationship (can accept Class II).
No rotations, spaces, flat occlusal plane.

Question 6

What are the Andrews’ six keys for perfect occlusion ?

Answer 6

1.
Molar relationship: the distal surface of the disto-buccal cusp of the upper first permanent molar occludes with the mesial surface of the mesio-buccal cusp of the lower second molar.

2.
Crown angulation (mesio-distal tip): the gingival part of the long axis of the crown is distal to the incisal part of the axis. The extent of angulation varies according to tooth type.

3.
* Crown inclination (labio-lingual, bucco-lingual): the incisors are at a sufficient angulation to prevent overeruption.
* Upper posterior teeth: the lingual tip is constant and similar from canine to second premolar and increased in the molars.
* Lower posterior teeth: the lingual tip increases progressively from the canines to the molar.

4. Rotations are not present.
5. There are no interdental spaces.
6. There is a flat plane of occlusion.

Question 7

Define compromised treatment.

Answer 7

Correction of certain aspects and accepting others i.e. accept buccal cross bite with no mandible displacement.

Question 8

Should treatment plan for upper or lower arch be decided first ?

Answer 8

Lower.

Question 9

How do you carry out crowding assessment ?

Answer 9

Measure space available and space required.
Overlap technique can be used from casts.