Management of impacted canines

1. Management of
impacted canines
AIMEE LIU

2. Canine impaction
 Impacted tooth is one that fails to erupt and will not attain its
anatomical position beyond the chronological eruption date even after
its root completion
 Maxillary canine has the longest and most tortuous path of eruption,
starting from high in the anterior floor of the sinuses below the orbit
 The tooth has a long distance to travel hence has a greater chance of
“losing its way”

3. Canine eruption
 4-5 months
 Formation starts between roots of the Ds
 12 months – calcification
 8-10 yrs – position changes
 Migrates from palatal to buccal
 Some canines do not make transition from palatal to buccal side
of dental arch and remain palatally impacted
 8-12 yrs ago
 ugly ducking phase
 not enough room for lateral incisor to upright
 Final phase:
 canines drive their way in between lateral incisors and first
premolars, forcing these teeth to become upright
https://www.slideshare.net/AnalhaqShaikh/canine-
impaction-and-its-importance-in-orthodontics

4. Epidemiology
 Second most frequently impacted teeth (after wisdom teeth)
 Prevalence
 Mx canines 3%
 of these, 8% are bilateral canine impaction
 Md canines 0.3%
 Females : Males = 2:1
 Mx canines:
 85% palatal; 15% buccal
 CBCT analysis: 45.2% buccal; 40.5% palatal; 14.5% midalveolus1

5. Aetiology
 Exact cause unknown
 Systemic factors
 Disturbances in tooth eruption sequence (endocrine deficiency, febrile
diseases, irradiation)
 Two theories proposed:
 Guidance theory
 Canine erupts along root of lateral incisors, which serve as guide, and if lateral incisor
absent or malformed, the canine will not erupt
 Other local factors
 Genetic theory
 Genetic factors are primary origin of palatally displaced maxillary canines and include
other possibly associated dental anomalies, such as missing or small lateral incisor
 Arch length deficiency – buccal canine impactions

6. Consequences
 Malposition of adjacent teeth
 Loss of arch space
 Resorption (of canine or
adjacent teeth)
 Cysts
 Complicates orthodontic
treatment
 Affects occlusion
 Compromised aesthetics
https://www.sylvainchamberland.com/en/dentition-en/impacted-canines/impacted-teeth-canines/

7. Clinical presentation
 Over-retained deciduous canine
 Asymmetry in exfoliation of deciduous
canine
 Lack of canine bulge on buccal aspect of
ridge by age 10
 Palatal bulge
 Lack of deciduous root resorption
 Persistent midline diastema or anterior
spacing
 Malposed adjacent lateral incisor

8. Predicting canine impaction
Sector Predictive
I 0.06
II 0.38
III 0.87
IV 0.99
https://www.jco-online.com/archive/2013/08/490-prediction-
of-maxillary-lateral-incisor-root-resorption-using-sector-
analysis-of-potentially-impacted-canines/

9. Investigations
 Plain films
 OPG
 Occlusal views
 SLOB rule
https://www.slideshare.net/AnalhaqShaikh/canine-impaction-and-its-
importance-in-orthodontics

10. Investigations: CBCT
 Shows:
 Presence of absence of canine
 Buccal / palatal position
 Size of follicle
 Inclination of long axis
 Amount of overlying bone
 Proximity to adjacent roots
 Resorption of adjacent roots
 Root form
 Presence of any pathology

11. Treatment goals
 Eruption of impacted canine into arch
 Maintain adequate attached gingiva
 Aesthetic gingival contours
 Avoid damage to adjacent teeth

12. Treatment options
1. Retain and monitor impacted canine
2. Extract impacted canine, camouflage with primary
canine
3. Extract impacted canine, premolar substitution
4. Extract impacted canine, replace with implant
supported crown
5. Surgical exposure of canine, guide into arch with
orthodontic traction
6. Autotransplantation of impacted canine into arch after
ortho pre-treatment

13. Considerations
 Patient age
 Arch space availability
 Suitability of first premolar to replace canine
 Position of impacted canine
 Status of primary canine
 Patient motivation for orthodontic treatment
 Medical contraindications for surgery

14. Interceptive treatment
 Early signs of ectopic eruption of canines
 Prevent impaction and potential sequelae
 Selective extraction of deciduous canines as
early as 8 or 9 years of age
 Normalise eruption of ectopically erupting
canine
 Ericson and Kurol 1988
 Relationship of cusp tip of canine to long axis of
lateral
 92% erupt if the canines overlap the laterals
less than ½ the root
 64% erupt if the canines overlap the laterals
more than ½ the root

15. Surgical options
 Open
 Labial/buccal
 Gingivectomy
 Apically positioned flap
 Palatal
 Closed eruption
 Favoured when tooth more deeply embedded in
bone since open exposure may necessitate
excessive bone removal
 Raise flap, expose and bond eruption device, then
close flap
 Tunnel technique – extraction of deciduous canine
https://www.slideshare.net/mohammedalawdi2/traction-
of-impacted-maxillary-canine

16. Surgical options: factors to
consider
 Position of impacted canine
 Labial/Buccal vs palatal
 Intra-alveolar
 Palatal
 Amount of keratinised gingiva present
 Amount of bone overlying impacted canine
 Surgeon’s preference
 Moisture control
https://www.researchgate.net/figure/Marginal-free-gingiva-attached-gingiva-and-
alveolar-mucosa_fig4_237819432

17. Surgical options: labial canines
 Closed vs open exposure
 Open exposures
 Teeth need to erupting through keratinised gingivae – ideally
have 3mm
 Gingivectomy
 Apically repositioned flap
Gingivectomy ARF
https://pocketdentistry.com/8
-surgery-as-an-aid-to-
orthodontics/

18. Surgical options: palatal canines
 Closed vs open
 Longer duration of pain and need for analgesia
 Longer duration of impaired oral function
 Food intake
 Swallowing
 Mouth opening
 Increased food accumulation
 Open exposure:
 Bond and traction vs free eruption
 Resorption of teeth
 Ortho traction on palatally impacted canines can cause resorption to adjacent
teeth, esp laterals
 Lingual buttons/TADS can be used as anchorage to pull canines away from
adjacent teeth as the initial movement

19. Surgical options - decisons

20. Armamentarium
 Anaesthetic considerations
 Nasal tube
 Set-up
 Diathermy – monopolar, bipolar
 Piezoelectric handpiece
 Gold chain
 Etch/bond or self-etching primer and bond
 Transbond Plus
 Curing light
 Bracket holders vs tweezers vs tissue forceps
 Practise loading
 Triplex vs sterile syringe
 Silk sutures
 COE-PAK, Vaseline
 Maintaining sterility

21. Case Study: KI
 13F with referred from Ortho for mx of ectopic 13, 23
 Med hx: asthma
 Allergies: cashew nuts
 Has a brother with impacted canines as well
 Orthodontic assessment
 Class I – 3mm overjet
 Mesofacial profile
 12 endodontically treated for dens

22. Case study: KI

23. Case study: KI

24. Treatment plan
 SR 53, 63
 13 palatal impaction
 wide exposure through tunnel technique,
bonding of gold chain
 23 labial impaction
 apically repositioned flap, bond gold chain on
buccal surface

25. KI: 13 tunnel technique

26. KI: 23 apically positioned flap

27. Case Study: KI
 Complication
 Surgical avulsion 13
 Root intact, replanted within ten seconds
 Concerns
 De-vitalisation requiring TRCT/ankylosis/resorption
 2nd mucosal surgery under LA to removal mucosal tissue re-exposure required
 Loss of tooth/extraction/replacement including implant
 Open disclosure
 VHIMS
 Documentation

28. References
 Liu et al. Localization of impacted maxillary canines and observation of adjacent incisor
resorption with cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol
105(1):91-98, 2008
 Ericson et al. Early treatment of palatally erupting maxillary canines by extraction of the primary
canines Eur J Orthod 1:283-295, 1988
 Warford et al. Prediction of maxillary canine impaction using sectors and angular measurement.
Am J Orthod Dentofacial Orthop 124(6):651-655, 2003
 Schindel, R.H. and Sheinis, M.R., 2013. Prediction of maxillary lateral-incisor root resorption using
sector analysis of potentially impacted canines. J Clin Orthod, 47(8), pp.490-3.
 Bedoya, M.M. and Park, J.H., 2009. A review of the diagnosis and management of impacted
maxillary canines. The Journal of the American Dental Association, 140(12), pp.1485-1493.
 Schmidt, A.D. and Kokich, V.G., 2007. Periodontal response to early uncovering, autonomous
eruption, and orthodontic alignment of palatally impacted maxillary canines. American Journal of
Orthodontics and Dentofacial Orthopedics, 131(4), pp.449-455.
 Shapira Y, Kuftinec MM. Early diagnosis and interception of potential maxillary canine impaction. J
Am Dent Assoc. 1998;129:1450–4

29. Acknowledgements
 Slides adapted from presentation by Dr Sam Huang
 Thank you to team involved with case study:
 Mr Roland Barrowman (OMFS)
 Dr Shangeetha Gunasekaran (Paeds)
 Dr Adam Wallace (Ortho)

30. Thank you