Treatment of class I malocclusion

Question 1

What is the classification of incisor class I relationship?

Answer 1

Lower incisor occludes at or below the upper incisor cingulum plateau

Question 2

What are the different problems with class I incisors?

Answer 2

Crowding
Spacing
displaced teeth

Question 3

What is the aetiology of crowding?

Answer 3

Jaw size
Tooth size
Arch perimeter

Question 4

What is the most commonly displaced tooth?

Answer 4

Upper canine

Question 5

How can you fix class I incisor crowding?

Answer 5

Expansion
Distal movement
Enamel stripping
Extraction

Question 6

What are the problems with expansion

Answer 6

relapse
fenestration of the labial plate
aesthetics - expand too much doesn’t look good

Question 7

What appliances can be used for expansion to treat crowding?

Answer 7

The schwarz applliance - removable can only tip teeth
Quad helix
Fixed appliances

Question 8

What is the average expansion and relapse of mandibular expansion? What does this mean

Answer 8

Average expansion = 3.7mm
Average relapse = 2mm
Expansion of arches using removable appliances if very unstable

Question 9

What is the difference in long term success if do non-extraction expansion vs extraction of premolars

Answer 9

Non-extraction only 10% long-term success

Premolar extractions 30% long-term success

Question 10

What are the limits to extraction in the arch?

Answer 10

incisors = 2mm
Canines = 0mm
Molars = 3mm

Question 11

what is fenestration of labial plate?

Answer 11

apex of the tooth is pushed out of the buccal bone

some bone loss so that directly in contact with alveolar mucosa or gingiva

Question 12

How can you distalise teeth in the uper arch?

Answer 12

Headgear (and/or removable appliance TB or FA)
Non-compliance appliances
Temporary anchorage devices

Question 13

How can you distalise teeth in the lower arch

Answer 13

Lip bumper

Question 14

Which is the only removable appliance headgear can be used on?

Answer 14

Twin block

Question 15

What is an example of temporary anchorage device?

Answer 15

Mid palata implants
Osseo-integrates, fused to bone
creates space and difficult to take out
Now can use mini ones fused to bone with spring to distalise molar
Equal and oposite forces pushing the tooth forwards

Question 16

What are the 2 non-compliance applicances?

Answer 16

Pendulum appliance - increases the overjet

Distal jet

Question 17

How does a lower lip bumper work?

Answer 17

uses pressure from lip to disalise the molars
Can break a lot and impact on 7 and 8
it doesnt work

Question 18

What is enamel stripping/interproximal reduction?

Answer 18

Use abrasive metal strips, air-rotor stripping
remove up to 0.25mm enamel from contact points
Removing some enamel to create enough space

Question 19

What 3 ways can you have spacing?

Answer 19

Upper midline diastema
Generalised spacing
Missing teeth

Question 20

What is an upper midline diastema?

Answer 20

Roots converging, distalling inclines with prominent labial frenum

Question 21

How do you determine whether to keep the space open or close it if have missing lateral incisor?

Answer 21

Malocclusion
Molar relationship
Space present

Question 22

Is it better to keep the space open or use restoratives to close it?

Answer 22

Better to close as otherwise would need to be restored thoughout life

Question 23

If have missing lateral incisors and
a) class II incisors
b) class III incisors
What are the options

Answer 23

Class II - close the space

Class III - open the space

Question 24

What is the percentage of buccal and palatal impaction of canines?

Answer 24

Palatal impaction = 85%

Buccal imapaction = 15%

Question 25

If have a palatally impacted canine what are the options?

Answer 25

Leave in situ and monitor
Extract
Expose and align - most commonly done
Transplant

Question 26

What are the options for buccally impacted canine?

Answer 26

open exposure - apically repositioned flap

Closed exposure - attach gold chain