Management of Ectopic Maxillary Canine Flashcards
• Know the normal development of the maxillary canine and the importance of this; • Know the features associated with the ectopic eruption of maxillary canines; • Be aware of the various management options so that you can advise patients • Be able to explain the clinical and radiographic methods of locating an ectopic canine • List the possible treatment options of labially and palatally impacted canines.
Normal characteristics
Palpable in buccal sulcus at 9-10 years where they form
Erupts 11-12 years (earlier in lower arch)
Width 7-9mm
Larger than Primary
Ectopic characteristics
Prevalence 1-3%
More in palatal than buccal but now 1:1
8% bilateral
Associated with missing or diminutive lateral incisors
Aetiology
2 main theories
Familial/genetic - more common in girls and associated with other genetic anomalies e.g hypodontia
Guidance theory - long path of eruption + diminutive lateral incisors = lack of guidance into normal position
Long eruption path - due to formation more superiorly
Crowding - chronology of eruption - esp in buccally placed canines - canines erupt after other anteriors therefore no space
Narrow upper arch
Lack of resorption of primary tooth i.e C therefore no space
Follicular disturbance - often with 8s –> enlarged follicle
Assessment - two necessary methods
Clinical - first
Radiographic
Difference between ectopic and impacted
Ectopic is in wrong place
Impacted may be in right place just prevented from erupting
Assessment - clinical
Palpation - buccally - canine bulge
Mobility of primary tooth - C - suggests root resorption
Space present
Angle of lateral incisor
Inclination of lateral incisors
Proclined - crown of 3 is resting on root of 2 - proclining 2
Assessment - radiographic
Parallax - locate canine
Resorption of primary C - status
Parallax
Methods
Taking two films of same object at two different angles - apparent displacement of an object relative to the image of a reference object caused by the change in the angle of the tube
Central/lateral incisors used as reference object
OPT
THEN
Upper standard occlusal - 65-70 degrees at occlusal plane
Principle of parallax
If canine moves in same direction as tube (up) - lingual
If canine moves in different direction to tube (up) - buccal
Same
Lingual
Opposite
Buccal
Complications of ectopic canines
Root resorption of interfering teeth
Ankylosis
Cysts which are rare
Eruption under bridge or denture
Intervention/interceptive treatment
Extraction of C before 11 y/o - sometimes creates sufficient space for 3 but cautious in case 3 doesn’t come down
91% improvement of canine crown distal to lateral midline
64% if mesial to midline of lateral
Management of ectopic canine
Leave
Extract
Orthodontic alignment
Transplant
Management of ectopic canine - leave
No space
Good aesthetic anyway
Wildly displaced - no chance of erupting/resorbing other teeth
Management of ectopic canine - extract
Position of canine - affecting potential orthodontic movement of other teeth e.g crown overlying apex of other teeth
Management of ectopic canine - orthodontic alignment
2 main options
3rd newer option
Open exposure
Closed exposure - bond gold chain
Create space - encourage natural eruption
Displaced maxillary canine
85% palatal
15% buccal
via CBCT stats
Displaced canines - palatal impactions
Options for treatment
Leave
Extract
Expose + align
Transplant
Management of ectopic canine - orthodontic alignment OPEN EXPOSURE
Surgery to cut window in palatal soft tissues
Bone is cut away to exposure canine
Pack of gauze sutured in to cover canine - 7-10days to prevent soft tissues growing over canine tooth
Allows normal eruption
Can take 3 years of orthodontics
Management of ectopic canine - orthodontic alignment - CLOSED EXPOSURE - bond gold chain
Disadvantage
Adults more likely to develop ankylosis of canines - more likely to be fused to bone and won’t move with orthodontics
GA
Surgeons expose canine and bond gold chain to canines
Fixed appliance attached to chains and used to bring teeth into alignment
Disadvantages - don’t know which angle the canine will come out
Study found no difference in periodontal or surgical outcomes
Management of ectopic canine - orthodontic alignment - CREATE SPACE
Encourage natural eruption non-surgically
Quad helix - increases perimeter of arch
Push coil - pushes teeth apart around C to make space for 3 to erupt
6 month treatment
Buccal canines
Buccally impacted - soft tissue
Buccal impaction
Open exposure
Closed exposure
Buccal impaction - open exposure -
apically repositioned flaps reflect soft tissues buccally and reposition apically suture higher up tooth attached gingiva higher bracket applied to tooth
Transplantation
When
Canine ankylosed - fused to bone - ortho ineffective
Pt not suitable for ortho
Poor prognosis primary canines
Adequate space
No over eruption of opposing teeth e.g lower 3
Too misaligned for ortho
Transplantation
When
follow up
Canine ankylosed - fused to bone - ortho ineffective - trauma excessive - more damage to PDL –> external resorption
Pt not suitable for ortho
Poor prognosis primary canines
Adequate space
No over eruption of opposing teeth e.g lower 3
Too misaligned for ortho
RCT within 10 days
Transplantation - prognosis
5 years - 72%
10 years - 54% good prognosis
Summary
Diagnose early
Get advice
