Management of the ectopic maxillary canines Flashcards
When is the maxillary canine palpable and when does it erupt?
Palpable at 9-10 years
Erupts 11-12 years
What is the width of maxillary canine?
7-9mm mesially distally
What is the difference between ectopic and impacted?
Ectopic - in the wrong place and unerupted
Impacted - not able to come through but could be in the right place
What is the prevalence of ectopic maxillary canines?
1-3%
8% are bilateral
What are ectopic maxillary canines associated with?
Missing or diminutive lateral incisors
What is the aetiology for ectopic maxillary canines?
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)
What is involved in the clinical assessment?
Palpation
Mobility of primary tooth
Space
Angulation of lateral
What is involved in the radiographic assessment?
Location of the canine - parallax
Resorption of primary tooth
What does a proclined lateral incisor suggest?
Crown of the 3 is sitting on the 2 - suggesting the canine is buccally placed
What does parallax tell us?
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
What is parallax?
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
What is the definition of parallax?
What are the reference objects?
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
What is the SLOB rule?
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
What are the complications of having ectopic canines?
Root resorption
Ankylosis
Cysts around the canines
Eruption under bridge or denture
When should extraction of the canine take place?
Before 11 years old
When do you get a a good outcome?
When is the outcome not as good?
91% improvement if canine distal to midline of lateral
64% improvement if mesial to lateral (more ectopic)
What are the different ways of managing ectopic canine?
Leave
Extract
Orthodontic alignement
Transplant
Why may you want to extract the ectopic canine?
The position of the canine too difficult to align orthodontically
Crown of 3 overlapping apex of 1 and 2
What are the 3 ways of doing orthodontic alignment to allow space for eptopic canine
Open exposure
Closed exposure
Create space?
What is the open exposure treatment?
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
What is the problem with getting ankylosis?
the canine will fise to the bone and get stuck
now have to take out C’s and 3’s
What is closed exposure treatment?
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
What is a disadvantage of closed exposure?
Don’t know the angle you’re pulling on the canine
How does creating space help the ectopic canine ?
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
What is the benefit of creating space?
No need for GA but this doesnt always work
What do you do if have buccally placed canines?
Do apically repositioned flaps or closed exposure
In which patients would you consider transplantation?
Canine ankylosed Patient not suitable for ortho Poor prognosis canines adequate space no over-eruption of opposing teeth Too misaligned for ortho
What are the problems with transplantation
The canines long-term prognosis
Canines have a closed apex- wont revacularise, need to do RCt within 10 days otherwise get external resorption
What is the prognosis of transplantation?
After 5 years 72% had a good prognosis
After 10 years 54% had a good prognosis
What is the percentage of palatal impaction and buccal impaction
palatal 85%
Buccal 15% - arguably in the right place as should fall buccally
What is the most widely accepted aetiology?
Genetics?
What age should canines be assessed?
9-10
