Orthodontic Assessment

Question 1

Why orthodontic assessment (3)

Answer 1

Determine if there is malocclusion
Identify any underlying causes
Decide if treatment is indicated

Question 2

When should OA take place

Answer 2

Brief exam at age 9
Comprehensive when premolars and canines erupt, usually 11-12
HOWEVER MALOCCLUSIONS USUALLY PRESENT IN ADULT LIFE

Question 3

What is the ideal occlusion

Answer 3

Gold standard by which occlusal irregularities may be judged

Question 4

Andrews 6 keys of ideal occlusion

Answer 4

1. Class 1 molar relationship (disto-buccal cusp upper 6 occludes with mesio-buccal cusp of lower 7)
2. Crown angulation
3. Crown inclination
4. No rotations
5. No spaces
6. Flat occlusal planes (no curve of spee)

Question 5

HPC

Answer 5

Presenting complaint - prioritise if multiple
How much does this bother the pt?
How long have they had malocclusion for?
SOMETHING CHANGING RAPIDLY MAY INDICATE PATHOLOGY
MH DH SH FH

Question 6

MH contraindications to to orthodontic treatment

Answer 6

Allergy ( Ni or latex) nickel in NiT arch wires but unlikely to leech out, more likely to be from stainless steel brackets
Poor controlled epilepsy, avoid removable appliances.
Certain drugs can lead to gingival inflammation, difficulty cleaning brackets
Any condition that involves regular imaging/MRI of head and neck need to remove fixed appliance

Question 7

PDH

Answer 7

Frequency of attendance, how acclimatised
25 visits usually -> pt needs to be comfortable in chair
Prev Tx, lots of restorative work poor candidate for ortho. Prove diet and OH are better.
Trauma e.g. RCT leading to root resorption -> can ankyloses

Question 8

Social/Family History

Answer 8

Travelling distance/time
Parents work? CONSENT
School exams etc

Question 9

Habits

Answer 9

Thumb sucking
Lower lip sucking
Tongue thrust
Chewing finger nails -> root resorption

Question 10

Extra oral examination

Answer 10

Skeletal bases
Soft tissue
TMJ

Question 11

What occlusion should involve comparing pt to parent

Answer 11

Class III e.g. boy comes in with dad and he has larger mandible it’s likely pt will grow that way

Question 12

How are facial skeletal patterns considered

Answer 12

In THREE planes
Antero-posterior
Vertical
Transverse

Question 13

What MUST be ensured when assessing skeletal base

Answer 13

Frankfurt plane parallel to floor
Get pt to look in mirror

Question 14

How to assess antero-posterior skeletal base

Answer 14

Palpate skeletal bases
Visual assessment

Question 15

Skeletal class measurements

Answer 15

Class I- A point 2-3mm in front of B point
Class II A point> 3mm from B
Class III mandible in front of maxilla

Question 16

What is skeletal palpation

Answer 16

Gloves, fingers on skeletal bases behind lips
(Takes soft tissues out of equation)

Question 17

How to assess vertical skeletal base

Answer 17

Frankfurt-Mandibular Planes Angle FMPA
(Angle between Frankfurt angle and mandibular plane)

Question 18

Where do you want FMPA to meet

Answer 18

Two lines should meet at back of head at occipital bone

Question 19

Increased FMPA

Answer 19

Lines meet well before back of head (e.g. at ears)
Called high angle
No contact anteriorly

Question 20

Decreased FMPA

Answer 20

Lines don’t meet at back of head
Deep bite

Question 21

Lateral skeletal assessment

Answer 21

Mid sagittal reference line (check for asymmetry)
Good for picking up mandibular asymmetry
If so look down from top of head and see if chin is off centre

Question 22

Lip assessment

Answer 22

Competent/incompetent
Lower lip level
Lower lip activity

Question 23

Tongue assessment

Answer 23

Position
Habits
Swallowing