unerupted ectopic canines

Question 1

tx options if buccally displaced

Answer 1

relieve crowding
ext
exposure - apically repositioned flap

Question 2

incidence

Answer 2

1-2% in a caucasian population

Question 3

aetiology/possible causative factors

Answer 3

long path of eruption

genetic link - association with other dental anomalies (class 2/2 malocclusion, missing/diminutive U2s), females more commonly affected

crowding - canine often last tooth to erupt

ectopic position of the tooth germ

Question 4

factors influencing tx planning

Answer 4

attitude/motivation of pt
any underlying malocclusion?
presence of any pathology esp RR of adjacent teeth?
position of the UE canine

Question 5

tx options

Answer 5

accept
surgical removal
surgical exposure and ortho alignment with fixed appliances
autotransplantation

Question 6

tx options - accept

Answer 6

are things likely to improve on their own?
can you make space? is there space?
should c be extracted? will it make much difference?
location
pt age

Question 7

risks of leaving the canine UE

Answer 7

resorption of the roots of the adjacent teeth (40% risk of lateral incisor root resorption)

resorption of the canine crown (14%)

ankylosis of the UE canine

eventual loss of c and complex restorative solutions may be required in future

cystic change of canine (rare)

Question 8

if you leave canine UE what should be done?

Answer 8

radiographic monitoring

Question 9

indications for surgical removal of the ectopic canine

Answer 9

canine not deemed alignable

if there is no significant risk of damaging the adjacent teeth during a surgical procedure

pt is happy with the dental appearance and the retained c has a good long-term prognosis

there is radiographic evidence of early RR of the adjacent teeth

pt does not want to wear ortho appliances

Question 10

factors which deem the canine not alignable

Answer 10

too high - above apical 1/3 of incisor roots

too close to dental midline

angle >55 degrees to mid sagittal plane

Question 11

at what age should you palpate for canines?

Answer 11

10-11years

Question 12

tx options - surgical exposure and ortho alignment with fixed appliances

Answer 12

make sufficient space for the tooth. A retained c may require removal

surgically expose canine - open or closed depending on site of canine

ortho traction - gold chain (closed exposure) or a traction hook (open exposure)

U and L fixed appliances - high anchorage demanding - may need palatal arch

fixed and removable retainers

Question 13

indications for autotransplantation

Answer 13

malposition of the tooth is too great for ortho alignment to be possible

there is no evidence of ankylosis of the canine

the canine root development is ideally 2/3 to 3/4 length root

pt is looking for a quicker tx option

Question 14

additional risks of autotransplantation

Answer 14

pt may need to undergo RCT of the transplanted tooth

pt needs to accept risk of ankylosis or external RR of the transplanted tooth

Question 15

additional risks other than routine ortho risks

Answer 15

sometimes a second surgical approach becomes necessary
failure to achieve tx objectives (e.g. if tooth doesn’t respond to ortho forces) is possible
long-term retention required - palatal canines relapse risk