Ortho

Question 1

How does cleft palate happen

Answer 1

Failure of fusion of the palatal shelves

Question 2

What are 4 genetic aetiolgies that can lead to the formation of a CLP

Answer 2

Syndromes; CP 50% will have a cardiac abnormality due to neural crest migration.

Family history ; if your first child has CLP 5% likely your next child will

Sex ratio

Laterality ; more common on the left than the right

Question 3

The smoking ban has reduced the number of babies born with CLP by what

Answer 3

10%

Question 4

The lip of a child with CLP is closed at around three to six months - why isnt the palate also closed at this time. When is it closed

Answer 4

This is because children are primary nasal breathers until they are 6 months
So the surgery is done between 6-12 months
Want it down by 12 months as this is when the baby will start to make sound

Question 5

What are the three compulsory surgeries in CLP

Answer 5

Lip closure
Palate closure
Bone graft

Question 6

There are 5 main dental implications for a child with CLP - what ar they

Answer 6

Missing teeth
Impacted teeth
Crowding - Relaspe rate is high , constricted upper arch and are likely to have descidious teeth extracted leading to crowding
Growth - they have a 20% tendency to be a class 3
Caries ; cannot bone graft to a child when they have caries and this can be a big issue in this group
- teeth come through hypoplastic and this makes them diffuckt to clean

Question 7

How do we clinically assess for an impacted canine

Answer 7

Palpate - buccaly and palatal
Check for mobility of the C
Look at the angle of the lateral incisor - often is the canine is palatal it may tip the lateral distally - it may also have resorbed the root so check mobility

Question 8

What interceptive method can be used to help with impacted canines

Answer 8

Early removal of teh Cs at the age of 10
This only works in palatal canines are as often the C is obstructing the eruption pathway

Question 9

When do we used a closed or an open exposure in impacted canines

Answer 9

If the canine is buccal
Needs to be a closed exposure and gold chain - the gold chain has to come down through the alveolar ridge to allow eruption onto the correct keratinised mucosa
Teeth will not erupt onto the non keratinised buccal mucosa as it doesnt have the proper cellular mechanism

If palatal placed
Open exposure and coal pack sutured in for 10 days
The palate is keratinsed so the canine can erupt

Question 10

When there is an unerupted tooth what two things do we look at

Answer 10

Symmetry and sequence of eruption

Question 11

What is the most common cause of an unerupted maxillary central

Answer 11

Super numerary - most commonly a tuberculate

Question 12

Not including the 8s what are the most common teeth affected by hypodontia

Answer 12

L5
U2
U5

Question 13

What is normal incisor width

Answer 13

6-7mm

Question 14

What is the minimum amount of space we need to root apex for an implant

Answer 14

7mm

Question 15

What is intramembranous ossification

Answer 15

Bone deposited directly into primitive mesenchymal tissue

Question 16

What is endochondral ossification

Answer 16

Bones are preceeded by a hyaline cartilage matrix

Question 17

The mandible and the maxilla form adjacent to pre-existing cartilaginous structures what are these

Answer 17

Mandible - mecjels cartilage
Maxilla - primary skeleton of the upper face

Question 18

How does cleft lip happen

Answer 18

Failure of fusion of maxillary prominence and medial nasal prominence

Question 19

What is interceptive ortho A

Answer 19

Any procedure that will reduce or eliminate the severity of a malocclusion

Question 20

If there is no 5 present and we are deciding to maintain an E why do we need to build it up into occlusion

Answer 20

Because if we don’t the 6 will drift and try and tip mesially over the top of it and the 4 will tip distally over the top and the occlsuion will become worse

Question 21

How do fixed appliances move teeth

Answer 21

They move teeth in a 3D way through bodily movement

Question 22

What is the order of movement with fixed appliances

Answer 22

1st in and out
2nd tipping and tilting
3rd torque

Question 23

In fixed appliances what kind of wire is use for initial alingment and why n

Answer 23

Nickel titanium

Light continuous force
Flexible
Shape memory
Higher friction than SSS

Question 24

When we have alinged teeth and are ready to apply 3rd order force to the teeth what kinf of wire is used

Answer 24

SS
This has less friction to allow the brackets to slide over each other to close the space
Allows control of torque movement

Question 25

Elastomeric power chains are used to close spaces - what is there disadvanaghre

Answer 25

They loose their pull over time due to the oral envirment so need to be replaced regularly

Question 26

Osteoblasts control all the reactions in tooth movement - what is hapeongin during compression

Answer 26

In areas of compression the osteoblasts bunch up together and expose the osteoid layer giving osteoclasts access to the bone
Osteoblasts send signals ie RANKL to osteoclasts to activate them

Question 27

In areas of tension what are osteoblasts doing

Answer 27

They are flattened covering the Osteiod layer preventing the osteoclasts from gaining access to the bone
They secrete OPG preventing osteoclast differnetion ans thier actvity

Question 28

The balance between what two things regulates bone remodelling

Answer 28

OPG and rankl

Question 29

Why do adults seek treatment

Answer 29

Improve dental appearance
Refused treamtent as a child
Facilitate restorative treatment
After periodontal drift
Part of surgical correction of jaw discrepancy

Question 30

Name 5 things that are different in adults to children receiving ortho

Answer 30

Lack of growth
Periodontal disease
Missing/ heavily restored teeth
Physiological factors
Adult motivation

Question 31

In terms of the periodontal tissues in adult ortho, previous ortho does not preclude treatment but what does

Answer 31

Active periodontal diease

Question 32

Loss of support of periodontal tissues in an adult ortho patient leads to what two things

Answer 32

Tooth centre of rotation moving apically
Anchorage value reducing

Question 33

What are 3 restorative reasons that an adult may receive ortho

Answer 33

Upright abutments to aid restoration ( i.e. path of insertion)
Intrusion of over erupted teeth
Extrusion to increase crown lenthj

Question 34

Perio patients must be stabilised before receiving orthodontic treatment - what do they need following treatment

Answer 34

Long term retention

Question 35

What are Andrews 6 keys

Answer 35

Tight approximal contacts with no rotation
Class 1 incisors
Class 1 molars
Flat occlusal plane or slight curve of spee
Long axis of the teeth have a slight mesial inclination expect lower incisors
The crowns of the canines back to the molars have have a lingual inclination