Canine Flashcards
Normal development of upper 3s
- Development of Upper 3s - 4-5 months high in maxilla
- Crown calcification complete - 6-7 years
- The upper 3s then migrate forward and downwards to lie BUCCAL and MESIAL to upper C.
- They erupt down the DISTAL aspect of upper 2.
Eruption date of Canine
- Upper 3s . 11-12 yrs
- Lower 3s 10- 11 years
Abnormal development of Canine
- Hypodontia
- Impaction
- Transposition
Hypodontia / developmentally absent U3s
- 0.08%
Impaction
- 2%
Ectopic Canine
- Occruing in abnormal position
Impacted Canine
- Canine that is prevented into its normal functional position by bone , tooth or fibrous tissue.
-Canine teeth may take ectopic eruption path and become Impacted.
Ectopic and impacted Upper 3s
Palatal percentage
- 61% palatal
Line of arch percentage?
- 34%
Buccal
5%
Unilateral: Bilateral
4:1
Femal : Male
70:30 more common in female
Aetiology of Ectopic and Impacted canine.
1- Long path of eruption of upper 3
2- Development absence hypodontia or short upper 2 ( Double the chance of palatally impacted upper 3s these patients due to lack of guidance during eruption. 42.6% chance
3- Genetic Predisposition
4- crowding / shortening of length or arch
5- Palatal = genetics , Buccal = inadequate arch space.
Problem associated with impacted 3s
- Resorption of adjacent tooth
- Cystic changes
- Long and complex treatment
Resorption of of adjacent teeth
- Upper 2s 1s or Both
- 2D-Radiographs 12% damage to adjacent lateral incisors
CBCT 3d rad- 66% resorption of U2s.
11% Upper 1s.
Cystic change result?
- resulting in damage to adjacent structure / teeth
2 Main theories Aetiology of Canine
- Guidance theory ( distal aspect of Upper 2 root)
- Genetic theory
What to watch out?
Diagnosing ectopic Canines
1- Upper 3s not palpable in buccal sulcus by age of 9-10 yrs.
2- Is upper C mobile?
3- Is the 3 on opposite side erupted ? 6 month rule.
4- Missing or small upper 2s.
5- Distal tipping or migration of Upper 2s
6- loss of vitality and increase mobility of U2 and 1.
7- Colour / angle of adjacent teeth
Diagnosing of ectopic Canine
Radiographically
- DPT / IOPA/ USO - Parallax / CBCT
When do we investigate for Impacted canine?
- If canine not palpable buccally at age of 9-10 yrs then investigate
How do we investigate impacted canine?
- Look , Observe - bulge, inclination and colour of lateral incisors.
- Palpation of canine crown - Buccal and palatal
- Mobility of UC or U2s
Radiographs to establish?
P3 rule - Presence , position and pathology
Which Radiograph to diagnose Impacted canine?
- Normal to use vertical or horizontal parallax to localise using:
-2 PA ( atleast 20 degree tube shift needed)
- Upper anterior occlusal + Peri apical
- Upper anterior occlusal + DPT
- Horizontal parallax b/w 2 periapicals - SLOB - Tube shift to right, Canine moved to right with tube then PALATAL POSITION.
Interceptive treatment define?
- Any treatment which eliminates or reduce the severity of developing malocclusion.
- Which may reduce the need for further treatment or simplify it
Chance of normalising of ectopic upper 3?
- Extraction of C in child age 10-13 years in Uncrowded mouth increase chance of normalisation of ectopic upper 3.
- Both C is often extracted to preserve centreline. Balancing extraction
- Improvement in Upper 3 position should be noted in 9-12 months following extractions of upper C.
Predictors of success of interceptive treatment
- Age - 10- 13 years
- Postion of canine
- Degree of crowding
Success of interceptive treatment Factor
2- Postion of Canine.
- Proximity to midline - Increased overlap of U2 decrease chance of normalising.
- Angulation (Tip) - Increased mesioangular angle decrease chance of normalising height
- Height - Increased height decrease chance of normalising
3- Crowding
- more crowding decrease chance of normalising
Buccally impacted U3s
- Ussually related to Crowding.
- Buccally placed Upper 3s more like to erupt over than palatal 3s due to thinner over lying of mucosa
- Relief of crowding part of treatment aim
- Can cause resorption of U2s
- In rare cases ankylosed
Palatal and buccal percentage.
- 70% palatal
- 30 % buccal