Management of the ectopic maxillary canines

Question 1

When is the maxillary canine palpable and when does it erupt?

Answer 1

Palpable at 9-10 years

Erupts 11-12 years

Question 2

What is the width of maxillary canine?

Answer 2

7-9mm mesially distally

Question 3

What is the difference between ectopic and impacted?

Answer 3

Ectopic - in the wrong place and unerupted

Impacted - not able to come through but could be in the right place

Question 4

What is the prevalence of ectopic maxillary canines?

Answer 4

1-3%

8% are bilateral

Question 5

What are ectopic maxillary canines associated with?

Answer 5

Missing or diminutive lateral incisors

Question 6

What is the aetiology for ectopic maxillary canines?

Answer 6

Familial/genetic - more common in girls
Long eruption path - higher in maxilla - have longer to go
Guidance theory - missing or small lateral incisors can’t guide it into position
Crowding - canines erupt after 1,2,3,5
Narrow upper arch
Lack of resorption of primary C
Follicular disturbance (mostly happens with 8’s)

Question 7

What is involved in the clinical assessment?

Answer 7

Palpation
Mobility of primary tooth
Space
Angulation of lateral

Question 8

What is involved in the radiographic assessment?

Answer 8

Location of the canine - parallax

Resorption of primary tooth

Question 9

What does a proclined lateral incisor suggest?

Answer 9

Crown of the 3 is sitting on the 2 - suggesting the canine is buccally placed

Question 10

What does parallax tell us?

Answer 10

Location of the canine - want to know exactly where it is to stick something to is or to remove it
Also tells us about the resorption of C

Question 11

What is parallax?

Answer 11

Take 2 films of the same object - canine at 2 different angles
OPT - usually done before ortho treatment
Upper standard occlusal - 65-70degrees to the occlusal plane

Question 12

What is the definition of parallax?

What are the reference objects?

Answer 12

Apparent displacement of an object relative to the image of the reference object caused by the change in the angle of the tube
Central and lateral incisors are the reference obbjects

Question 13

What is the SLOB rule?

Answer 13

If the tube moves up - from the OPT to upper standard occlusal and the canine moves up then LINGUAL
If the tube moves up and the canine moves in the opposite direction - then BUCCAL

Question 14

What are the complications of having ectopic canines?

Answer 14

Root resorption
Ankylosis
Cysts around the canines
Eruption under bridge or denture

Question 15

When should extraction of the canine take place?

Answer 15

Before 11 years old

Question 16

When do you get a a good outcome?

When is the outcome not as good?

Answer 16

91% improvement if canine distal to midline of lateral

64% improvement if mesial to lateral (more ectopic)

Question 17

What are the different ways of managing ectopic canine?

Answer 17

Leave
Extract
Orthodontic alignement
Transplant

Question 18

Why may you want to extract the ectopic canine?

Answer 18

The position of the canine too difficult to align orthodontically
Crown of 3 overlapping apex of 1 and 2

Question 19

What are the 3 ways of doing orthodontic alignment to allow space for eptopic canine

Answer 19

Open exposure
Closed exposure
Create space?

Question 20

What is the open exposure treatment?

Answer 20

Opens soft tissues away to allow normal eruption
Surgeon cuts a window in the palatal soft tissues and cuts bone away to see the canine
Can then suture in a pack of gauze to cover up the canine - to stop the soft tissues growing back over the canine
Want the canine to erupt then align with fixed appliance

Question 21

What is the problem with getting ankylosis?

Answer 21

the canine will fise to the bone and get stuck

now have to take out C’s and 3’s

Question 22

What is closed exposure treatment?

Answer 22

Surgeon exposes the canine, instead of having a hole in the palatal soft tissues, bond on a gold chain
This comes out into the mouth ans used to align the teeth

Question 23

What is a disadvantage of closed exposure?

Answer 23

Don’t know the angle you’re pulling on the canine

Question 24

How does creating space help the ectopic canine ?

Answer 24

Encourage natural eruption non-surgically
Use a quad helix to expand the arches
increasing the perimeter of the arch or could use push coil to push teeth apart and create more space
When create space around C, it becomes more mobile as the 3 aligns itself

Question 25

What is the benefit of creating space?

Answer 25

No need for GA but this doesnt always work

Question 26

What do you do if have buccally placed canines?

Answer 26

Do apically repositioned flaps or closed exposure

Question 27

In which patients would you consider transplantation?

Answer 27

Canine ankylosed 
Patient not suitable for ortho
Poor prognosis canines 
adequate space 
no over-eruption of opposing teeth 
Too misaligned for ortho

Question 28

What are the problems with transplantation

Answer 28

The canines long-term prognosis

Canines have a closed apex- wont revacularise, need to do RCt within 10 days otherwise get external resorption

Question 29

What is the prognosis of transplantation?

Answer 29

After 5 years 72% had a good prognosis

After 10 years 54% had a good prognosis

Question 30

What is the percentage of palatal impaction and buccal impaction

Answer 30

palatal 85%

Buccal 15% - arguably in the right place as should fall buccally

Question 31

What is the most widely accepted aetiology?

Answer 31

Genetics?

Question 32

What age should canines be assessed?

Answer 32

9-10