Ectopic Canines Flashcards
What are the problems with canines?
Ectopic
Transposed
Why are canines important?
- Corner stones of dental arch
- Long rooted teeth so good long term prognosis for perio
- Difficult replace prosthetically
What percentage of maxillary canines are ectopic?
2-3%
85% Palatal
15% buccal
What percentage of ectopic canines are associated with root resorption of the laterals?
12% more common with Palatal
How does the canine migrate during eruption?
It migrates down and forward distal to the root of the lateral incisor
At what age shoud canines be palpable in the buccal sulcus?
9/10
What age do canines erupt?
12
What are the causes for ectopic canines?
- Retained C
- Displacement of dental crypt
- missing laterals/diminutive lateral
- Crowding (especially buccally)
Why are missing or diminutive laterals associated with ectopic canines?
Less guidance
What do you need to examine when investigating canines?
Presence
Position
Pathology
What are the clinical signs of possibly ectopic canines?
Reference
brin et al 1986
- Not palpable in buccal sulcus by aged 10
- C’s not mobile
- Asymmetric loss of C’s
- peg shaped laterals
- Missing laterals
- labially inclined laterals which suggests buccal,impactin
What can you use as an adjunct to clinical examination to determine presence and location of 3’s?
Radiograph
What must you look for on the radiographically examination?
- C’s root resorbing?
- Any signs of pathology eg resorbing roots of laterals or centrals
- Determine position
What radiographically technique is used to determine the position of the 3’s?
Parallax
What is the principle to parallax?
Relative movement of the canine in relation to other adjacent teeth when two radiographs are taken with an angle between them
what rule do we use to determine the position of the tooth when using parallax?
SLOB
Same Lingual
Opposite Bucaal
What radiographic views can you use in horizontal parallax?
Ant occlusal and Periapical
2 pas
DPT and pa
What views can you use in vertical parallax?
DPT and ant occlusal
What interceptive techniques are there for impacted canines ? Ref
Ericsson and kurol 1988
1. Extraction of C’s
At age 10-13
Suggested 78% will improve of there is no crowding (power and short 1993)
When is interception indicated and more successful?
- Young patent ~10
- Space available
- 3 only overlaps lateral but not central
When is active treatment indicated ?
- Pt aged 13
- Crowded case
- If canine does not improve significantly 6 mths post extraction
What are the treatment options following ectopic canines?
- leave alone and review
- Expose and align
3.extarct plus or minus ortho
4 create space and replace
5.transplant
What are the factors to consider when deciding which treatment?
- Position of canine
- Crowding
- Age of pt
- Cooperation
- Condition of root of C
- Appearnce of lateral
- Other pathology
What circumstances would you leave the ectopic canine and review?
Canine in hopeless position
Pt not interested in treatment
Increased risks from surgery to pt
C has good root morph
MUST make sure review radiographically
What three things do you need to consider when assessing the position of the canine for ortho?
- Height
- mesio-distal position
- Angulation
Discuss the issues of canine height with regards to ortho prognosis ?
The crown tip of the canine is at or above the apical third of the incisor roots: POOR PROG
Discuss the issues of canine mesio distal position with regards to ortho prognosis ?
Canine is more than half way across the upper incisor : POOR PROG
Discuss the issues of canine angulation with regards to ortho prognosis ?
Smaller than angle with the occlusal place (the more horizontal) POOR PROGNOSIS
When is expose and alignment a good option?
Age: longer treatment period in older patient s
Co-operation: 2+yrs of treatment
OH
MH: since surgical treatment
T/F
Expose and Alignment is usually a treatment option of choice ?
T
In well motivated patients and canine in an okay position and enough space or can make space
What is important when there is buccal inaction?
Avoid pulling through non keratinised mucosa so need to
- bond bracket and gold chain or
- use an apically repositioned flap
How do you perform the expose and aligning?
Expose crown and leave to erupt for 8 weeks then apply traction
Buccal - closed exposure
Palatal - open exposure
When would you chose to extract plus or minus ortho?
In v crowded cases where 4/2 makes good contact
Poor prognosis for alignment and risk of lateral resorption
Patient not interested in ortho but leaving canine is a risk
What are the restorative treatment options?
Bridge: not ideal due to canine guidance on Pontic
Implant: not in growing patient
When would transplants be indicated?
Rarely
Poor long term prognosis and operator sensitive
Better prognosis if root is only 2/3 formed
Need ortho anyway to create space
Possibility of tooth ankylosis in growing pt
Which tooth are maxillary canines most commonly transposed with?
First premolar
Sometimes lateral
Which tooth are mandibular canines most commonly transposed with?
Lateral
What do you do in cases where the canine is transposed ?
Do not try to move the canine back
Accept and align with FA
Rotate 4 medically to hide Palatal root
What percentage of mandib canines are ectopic?
0.3%
Which gender have ectopic Maxilliary canines more?
Females
What are palatally impacted canines mainly caused by?
Polygenic
Multifacotrial
What is buccal canine impaction mainly causes by?
Crowding
