seminar on canine impaction

1. CANINE IMPACTION
Dr. Jeff Zacharia
Post Graduate student
Oral & Maxillofacial Surgery
AJ Institute of Dental Sciences

2. Contents
◦ Introduction
◦ Concepts of maxillary canine impaction
◦ Classification
◦ Clinical diagnosis
◦ Radiographic diagnosis
◦ Treatment options
◦ Surgical Technique
◦ Complications

3. Introduction

4. Introduction
With the exception of the third molar, maxillary canine impaction is considered to be the most
common form of tooth impaction. The position of the permanent maxillary canine at the angle of
the mouth is strategically important in preserving the harmony and symmetry of the dental arches.
The incidence of canine impaction in the maxilla is more than twice higher compared to the
mandible. Approximately one-thirds of the cases are labially located, and two-thirds are palatally
located. Bilateral impaction have been reported in 8% of the patients with canine impaction. The
treatment procedure is time-consuming and imposes a significant financial burden on the patient

5. Impacted Tooth
◦ A tooth which is completely or partially unerupted, is positioned against another tooth, bone or
soft tissue so that its further eruption is unlikely and described according to anatomic position
(Archer)
◦ An impacted tooth is defined as a tooth that is prevented from erupting into position because of
malposition, lack of space or other impediments. (Mead 1954)
◦ Impacted teeth are those teeth that fail to erupt into the dental arch within the expected time. (Peterson)
◦ Impacted teeth are those teeth that are prevented from eruption due to a physical barrier within the path of eruption
(Farman 2004)

6. Concepts of Impaction

7. Concepts maxillary canine impaction
 Becker Concept
Becker (1984) hypothesized two processes in palatal impaction of the maxillary canine:
1. Absence of initial early guidance from an anomalous lateral incisor
2. Failure of buccal movement of the canine at an unspecified age .
 MC Bridge Concept
Canine formed at high level in the anterior wall of antrum, below the floor of orbit have a tortous path
of eruption

8.  Moyers Concept: Summarized by Bishara
A) Primary cause:
1) Trauma to decidious tooth bud
2) Rate of Resorption of decidious tooth
3) Availability of space in the arch
4) Disturbance in tooth Eruption Sequence
5) Rotation of tooth buds
6) In Cleft area of cleft patient
7) Premature root Closure
B) Secondary cause:
1) Abnormal muscle pressure
2) Febrile diseases
3) Endocrine disturbances
4) Vitamin D deficiency.
AJO. 1992.Feb.Bishara

9. 1) Malnutrition
2) Tuberculosis
3) Syphilis
4) Rickets
5) Anemia
6) Progeria
7) Syndromes:
a) Cleidocranial dysplasia
b) Achondraplasia
c) Down syndrome
 Berger Concept (Systemic causes of impaction)

10.  Vonder Heydt Concept
“The total arch length for the permanent teeth is primarily established very early in life at
the time of eruption of the first permanent molars, and because the canine is large and late
in eruption, it is often not found in the alignment of the arch.
As in musical chairs, the room for this tooth is all gone, and it must assume an awkward and
embarrassingly inappropriate position on the arch alignment.”

11.  Miller’s Guidance Theory
According to the guidance theory, the presence of the lateral incisor root with right length and formed at the
right time are important variables needed to guide the mesially erupting canine in a more favorable distal and
incisal direction.
If excessive space exists due to malformed or absent lateral incisor, the canine would cross back from the
buccal to the palatal side behind the buds of the other teeth.

12.  Genetic Theory
This theory indicates multiple evidential categories for the genetic origin of palatally impacted canines,
such as: Familial and bilateral occurrence, Sex differences, as well as an increased occurrence of other
significant reciprocal dental associations such as ectopic eruption of first molars, infraocclusion of
primary molars, aplasia of premolars and one third molar.
Pirinen et al., showed that 106 patients with palatally displaced canines had first and second degree relatives with some
dental anomalies.

13. Classifications of canine impaction

14. Classification of impacted maxillary canine
BASED ON POSITION IN THE DENTAL ARCH
CLASS I: Impacted cuspids in palate
1. Horizontal
2. Vertical
3. Semi-vertical
CLASS II: Impacted cuspids on buccal surface
1. Horizontal
2. Vertical
3. Semi-vertical

15. CLASS III: Impacted cuspids located in the palatal
process and labial maxillary bone
CLASS IV: Impacted cuspids located in the alveolar
process usually vertically between the incisor and
bicuspid
CLASS V: Impacted cuspid located in an edentulous
maxilla

16. FIELD AND ACKERMAN CLASSIFICATION (1935)
MAXILLARY CANINES
 Labial position
1. Crown in intimate relationship with incisors
2. Crown well above the apices of incisors
 Palatal position
1. Crown near the surface, in close relationship to
roots of incisors
2. Crown deeply embedded in close relationship to
apices of incisors.
 Intermediate position
1. Crown is between lateral incisors and 1st premolar
roots.
2. Crown above these teeth where it is labially placed
and root is palatally placed or vice versa
 Unusual positions
1. In nasal or antral wall.
2. In infraorbital region

17.  Unusual positions
1. At inferior border
2. In mental protuberance
3. Migrated to the opposite side along with the original
nerve supply
 Labial position
1. Vertical
2. Oblique
3. Horizontal
MANDIBULAR CANINES

18. Ericson and Kurol (1988) classification
Sector 1: if the cusp tip of the canine is between the inter-
incisor median line and the long axis of the central incisor
Sector 2: if the peak of the cuspid of the canine is between
the major axes of the lateral and central
Sector 3: if the peak of the cuspid of the canine is between
the major axis of the lateral and the first premolar.

19. Classification for trans-positioned maxillary canines
According to Peck & Peck (1993)
Maxillary canine–first premolar(Mx.C.P1)
Maxillary canine–lateral incisor (Mx.C.I2),
Maxillary canine–first molar site (Mx.C to M1)
 Maxillary lateral incisor–central incisor (Mx.I2.I1)
Maxillary canine–central incisor site (Mx.C to I1)
Mandibular lateral incisor–canine (Mn.I2.C).

20. Classification of impacted mandibular canine
Based on angulation
◦ Mesio-angular
◦ Disto-angular
◦ Vertical
◦ Horizontal
Based on Depth
◦ Level A: The crown of the impacted canine tooth is at the cervical line of the
adjacent teeth
◦ Level B: The crown of the impacted canine tooth is between the cervical line and
root apices of the adjacent teeth.
◦ Level C: The crown of the impacted canines is beneath the root apices of the
adjacent teeth.
Yavuz et all, 2007

21. note: Transmigrated mandibular canine
◦ Transmigration is an intraosseous displacement of an unerupted tooth in which a movement
phenomenon causes it to cross midline by more than 50 % (Mupparapu et al)
◦ It has a prevalence of 0.31% .
Classification: Based on inclination, relationship with the midline, adjacent teeth and contralateral
erupted canine (Mupparapu et al)
Type 1: Canine positioned mesio-angularly with the crown portion of the tooth crossing the
midline.
Type 2: Horizontal impacted canine next to the lower border of the mandible and below the
incisors
Type 3: Mesially or distally eruption of the canine according to the opposite canine.
Type 4: Impacted horizontal canine below of premolars or molars on the contrary side and next
to the lower border of the mandible.
Type 5: Vertical Canine positioned in the midline

22. Diagnosis

23. Clinical Diagnosis
◦ Retention of primary canine in the dental arch beyond the 14th or 15th year of age.
(Becker 1993)
◦ Absence of canine eminence. (Ericsson & Kurol (2000) support the absence of the
canine eminence at the age of 10 – 12 years is not a sign of canine displacement.)
◦ Delayed eruption, distal displacement or distal inclination of lateral incisor. (Becker
1993)

24. Radiographic diagnosis
◦ Clark’s method suggests two periapical radiographs, the second one taken with the device cone
moving horizontally or vertically (Papadopaulous 2004)
◦ Jacobs (1996) recommends the combination of panoramic and occlusal radiographs, where the
cone is positioned vertically at a 70-750 angle.
◦ Use of axial tomography in cases where ankylosis is suspected (Traxler et al, 1989)
◦ The use of OPG offers the possibility for transverse parallel sections of the examined area by
changing the direction of the ray beam. (Broer et al, 2005)

25. Panoramic radiographs
Ericson and Kurol (1988) defined number of sectors to denote
different types of impaction
◦ Sector 1: if the cusp tip of the canine is between the inter-incisor
median line and the long axis of the central incisor
◦ ii. Sector 2: if the peak of the cuspid of the canine is between the
major axes of the lateral and central incisors
◦ iii. Sector 3: if the peak of the cuspid of the canine is between
the major axis of the lateral and the first premolar.
Angle α to represent the angle formed between the inter-incisor
midline and long axis of canine and “d” as the perpendicular distance
of the peak of the cuspid of the impacted canine with respect to the
occlusal plane.

26. ◦ The risk of resorption of the root of the lateral incisor increases by 50% if
the cusp of the canine belongs to sector 1 or 2 and if α angle is greater
than 25°.
◦ Linduaer et al. (1992) found out that 78% of canine were destined to get
impacted when their cusp tips located in sector II, III, IV.
◦ For Orthodontic purpose, The necessity of treatment and the degree of
treatment difficulty increases as this angle increases.

27. Periapical radiographs
simplest radiographs having minimum exposure.
provide us with information regarding
◦ state of development of tooth,
◦ the presence of follicle,
◦ resorption of deciduous tooth.

28. Occlusal view radiograph
◦ Assess whether the canine is impacted in a labial or palatal
position
◦ The X ray beam runs parallel to the long axis of the central
incisors.
◦ The cone is placed over the vertex of the skull to produce the
radiograph.
◦ Since the beam has to travel a great distance, there is loss of clarity

29. PA view
◦ It is used for prognostic evaluation.
◦ Evaluates the medio-lateral position of the canines.
◦ The angle formed between the long axis of the canine and the
transorbital line determines the degree of difficulty. As the angle
between the long axis of the canine and the transorbital line
decreases, the treatment difficulty increases.

30. Lateral cephalogram
◦ This technique is useful in establishing the height of the
impacted tooth and the anteroposterior position of the
canine with respect to the apices of the incisors.
◦ Evaluation of the impacted canine can be done by tracing
its long axis to and intersecting it with the Frankfurt
Horizontal plane.

31. Clark’s Rule or Parallax Method or Tube Shift Method
◦ Parallax is the apparent displacement of an image relative to the image of a reference object and is caused by
an actual change in the angulation of the x-ray beam.
◦ Two radiographs of the object are taken.
◦ First using the proper technique and angulation as prescribed.
◦ second, radiograph is taken keeping all the parameters constant and equivalent of those of the first
radiograph, only changing the direction of the central ray either with a different horizontal angulation or
vertical angulation.
◦ If the tooth shifts in the same direction as the tube then
the tooth is lingually placed and if it moves in the opposite
direction then it is buccally placed (SLOB- same lingual opposite buccal)

32. Right Angle Technique
◦ The right angle technique uses two radiographs taken at right angles to each
other.
◦ Ballard suggested the use of the combination of a lateral cephalometric
radiograph with a postero-anterior cephalometric radiograph for
localization of impacted maxillary canines.
◦ However, the position of the impacted tooth was often difficult to
interpret
◦ Additional intraoral film was required to see the fine detail of the impacted
tooth and its surrounding structures

33. 3-D Techniques: CT & CBCT
It gives information regarding
1. The exact position of the crown and root apex of the impacted tooth and
orientation of the long axis.
2. The proximity of the impacted tooth to the roots of the adjacent teeth.
3. The presence of pathology, such as supernumerary teeth, apical granulomas, or
cysts, and their relationship with the impacted tooth.
4. The presence of adverse conditions affecting adjacent teeth, including root
resorption.
5. The anatomy and position of crown and root
6. Provides excellent tissue contrast and eliminates blurring and overlapping of
adjacent teeth

34. Rapid prototyping
◦ Rapid prototyping aids in the communication between an
orthodontist and a surgeon in treatment planning.
◦ This technique comprises several technologies that use data from
computer-aided design files to produce physical models and devices
by a process of material addition.

35. Treatment options

36. Treatment Options
No treatment
Surgical removal of unerupted canine
Surgical exposure of the crown with or without orthodontic treatment
Surgical repositioning
Surgical transplantation

37. No treatment (to leave tooth in situ)
Risk of nonintervention
• Crowding of dentition based on growth prediction
• Resorption of adjacent tooth & periodontal status
• Development of pathological conditions such as infection, cyst, tumor.
Benefits of nonintervention
• Avoidance of risk
• Preservation of functional teeth
• Preservation of residual ridge

38. Surgical removal
Indications for surgical removal
◦ Impacted canine is located very far from the occlusal plane
◦ No other methods are possible to retain the tooth
◦ A patient not willing to undergo orthodontic treatment for longer duration
◦ Pathological changes in the crypt like infection, cyst formation, etc
◦ The required space does not exist for the canine tooth in functional position
◦ Because of unfavorable anatomy of the tooth, other methods like repositioning is not likely to be
successful.
Contraindications for Surgical removal
◦ When the cuspid can be brought into normal position surgically or orthodontically.
◦ Medically compromised patients presenting with impacted cuspids.

39. EXTRACTION OF CANINE IN CLASS II POSITION (i.e. labially placed canine)
1. Soft tissue flap is raised
TRAPEZOIDAL FLAP
Advantage:
◦ Provides excellent access
◦ Produces no tension in tissues
◦ Allows easy approximation of the flap to its original position
Disadvantage:
◦ Produces a defect in the attached gingiva
Surgical Technique
For maxillary canines

40. TRIANGULAR FLAP
Advantage:
◦ Ensures adequate blood supply.
◦ Satisfactory visualization
Disadvantage:
◦ Limited access to roots
◦ Tension is created when flap is retracted and results in defect in attached gingiva
SEMI LUNAR FLAP
◦ Used to approach root apex
◦ Avoids trauma to the papilla and gingival margin
◦ Should not cross canine eminence

41. 2. Circumferential bone removal done using chisel or bur to expose crown
3. Elevation of tooth using labial cortical plate used as fulcrum.

42. 4. Smoothening of the bone edges
5. Wound debridement & closure

43. EXTRACTION OF CANINE IN CLASS I POSITION (i.e. palatally placed canine)
1. Soft tissue flap raised
Surgical Technique

44. 2. Bone removal
Aim of bone removal
To expose the crown by removing the bone overlying it
To remove the bone obstructing the pathway of removal
Amount of bone to be removed
bone is removed circumferentially 3 mm around the crown
the crown is exposed till the CEJ so as to expose it beyond its
greatest width

45. 3. Sectioning of the tooth is done at the level of
the CEJ
4. Elevation of the tooth
 impacted tooth is lifted from the crypt using an elevator with
the palatal bone as fulcrum.
if tooth is not luxated, the opening has to be enlarged
5. Wound irrigation & closure
 all debris and spicules have to be removed.
 flap is compressed on to the palatal bone with a gauze packing
for 4 hours.
Or, a compound stent or clear acrylic plate may be used to
prevent hematoma collection & to maintain sustained pressure

46. EXTRACTION OF CANINE IN CLASS III POSITION (i.e. crown in palate & root on
buccal side)
On the buccal aspect,
1. Soft tissue flap is raised. (Semilunar flap)
2. Circumferential bone removal done.
3. Root sectioning done
On the palatal aspect,
4. Soft tissue flap is raised.
5. Bone removal is done
6. A blunt instrument is placed in contact with the root end on the buccal side and tapped with a mallet which drives
the crown out of the palatal crypt.

47. ◦ Trapezoidal incision extending from the lateral incisor as far as the
first premolar of the opposite side of the arch is made.
◦ Mental nerve has to be identified
◦ Bone removal done using chisel or bur to expose crown.
◦ Elevation of tooth using labial cortical plate used as fulcrum.
◦ Wound debridement & closure
For mandibular canines

48. Tunnel technique for deeply impacted canines
◦ The tunnel technique is a combined therapeutic approach that includes
both surgical exposure of the impacted canine and orthodontic traction
of the tooth to the center of the alveolar ridge, followed by final
orthodontic alignment
Indication
Persistence of the corresponding deciduous tooth
The presence of an adjacent lateral incisor with severe root resorption

49. Procedure
1. After the extraction of the deciduous tooth, a full-thickness flap raised to
expose cortical plate.
2. Cortical bone resected to expose crown of impacted canine.
3. Bone is drilled in the floor of the extraction socket to create an osseous
tunnel.
4. An anatomically contoured fine mesh is fixed to the centre of the cusp of
the impacted canine; wire chains passed through osseous tunnels for traction
5. The flap is sutured in its original position with the chain emerging from the
socket of the deciduous tooth through the osseous tunnel

50. Advantage
◦ A healthy periodontium at the completion of therapy is the
expected outcome
◦ Avoids the expense and inconvenience of prosthetic implants,
since the canines can substitute for the lateral incisors while the
first premolars take the place of the canines

51. Auto-transplantation of canine
◦ It is the movement of a permanent tooth from its ectopic position on to
the edentulous alveolar crest in the same patient.
◦ Auto-transplantation provides not only a biological replacement of tooth
which has potential to induce alveolar bone growth but also supports
proprioceptive function by maintaining a normal PDL.
◦ Auto-transplanted tooth has potential to erupt with neighboring teeth
during continued facial growth.

52. Procedure
◦ After flap elevation, osteotomy is performed using a round medium-size
bur (2-3 mm in diameter) at the area of the impacted tooth
◦ Atraumatic removal of donor tooth during operation is a prerequisite to
an optimal clinical result.
◦ In unfavorable canine inclination or ankylosis, tooth extraction and
subsequent auto-transplantation becomes impossible

53. ◦ Root canal treatment has to be performed after extraction of the donor tooth.
◦ For tooth placement, an infra occlusive position is preferred to avoid contact with its
antagonists at the occlusal plane.
◦ Tooth splinting can be done either using interdental sutures or by using an acrylic
splint or by splinting with a 26 gauge wire.

54. ◦ Orthodontic traction may begin after the end of the 4th post-surgical week (Czochrowska et al., 2002).
◦ Success of the tooth can be checked based on
a) Tooth mobility (grade II or grade III mobility)
b) Root resorption
◦ Success rate reported by Czochrowska et al. (2002) based on tooth mobility & root resorption ranged
from 79% to 90% during a 10-year period.
◦ Andersson et al. (1989) studied the rate of root resorption and found that it is increased at younger
ages.
◦ Bauss et al (2004) noted that the more extensive the surgical management for the auto-transplantation
of the impacted tooth (such as in the case of extensive alveolar resorption at the edentulous area), the
lower the long-term successful rate.

55. Complications

56. Complications
INTRAOPERATIVE COMPLICATIONS
During incision
◦ Incisive canal or greater palatine vessels may get damaged.
During bone removal
◦ Damage to the roots to the adjacent teeth
◦ Slippage of bur into soft tissue
◦ Fracture of the bone when using a chisel and mallet.

57. During elevation
◦ Fracture of adjoining bone
◦ Damage to nasal wall.
◦ Slippage of tooth into maxillary sinus
During debridement
◦ Damage to the maxillary sinus

58. POST OPERATIVE COMPLICATIONS
◦ Pain
◦ Swelling
◦ Hypoesthesia
◦ Sensitivity
◦ Sinus tract formation, oroantral fistula, oronasal fistula

59. Conclusion
Impacted canine is one of the common causes of seeking dental care. Its management requires an
appropriate approach for obtaining acceptable and adequate results. Several management options
are available. It is role of the clinician to thoroughly investigate patients with impacted canines both
clinically and radiologically, for the appropriate management technique.

60. THANK YOU