Management of impacted canines

Dr. Miliya Parveen
MANAGEMENT OF
IMPACTED CANINES

CONTENTS
• Introduction
• Incidence
• Development of canine
• Eruption of canine
• Etiology of canine impaction
• Sequelae of canine impaction
• Classification of canine impaction
• Diagnosis
• Radiographic Prediction
• Prognosis
• Prevention of maxillary impaction
• Extraction of impacted canine
• Treatment alternatives
• General principles of mechanotherapy
• Methods of gaining space
• Anchorage considerations
• Surgical Methods
• Surgical exposure for natural eruption
• One step vs two step
• Types of flaps
• Attachments
• Methods of traction
• Mandibular canine impaction
• Canine impaction and resorption
• Canine impaction and periodontium
• Retention
• Complications of treatment
• Complications of untreated impacted canine
• Conclusions
• References

INTRODUCTION
• An impacted tooth is defined as tooth whose roots are 2/3rd or fully
developed but nevertheless expected to erupt spontaneously.
• According to Shafer, Hine and Levy, impacted teeth are those which
are prevented from erupting by some physical barrier in the eruption
path.
• An impacted or unerupted canine tooth is usually easy to diagnose,
but the skill and expertise of the general practitioner, the
pedodontist, the oral surgeon, the periodontist as well as the
orthodontist are needed, to bring it, to its proper position.

INCIDENCE
• Mandibular third molar -- Maxillary canine -- mandibular second
premolar.
• Impacted maxillary canines are seen in 2% of the population
• Palatal canine impaction is more common (85%) than buccal canine
impaction.{Jacoby 3:1}. A ratio of twelve palatably impacted canines
for one labially impacted canine (Jaloby)
• It is twice as more common in females than males.
• Of all patients with impacted maxillary canines, 8% have bilateral
impactions.
• Incidence of maxillary canine impaction : 1.7% (Ericson)
• Incidence of mandibular canine impaction 0.35% (Dachi)

DEVELOPMENT
According to Broadbent, AO 1941-
• Canine develops at 4 – 5 months of age between the roots of
deciduous 1st molar.
• Calcification of canine - around 12 months of age.
• Calcification takes place far above the roots of deciduous molar,
allowing development of the first premolar between the deciduous
molar roots.

ERUPTION OF CANINE
• Dewel (1949) stated that “no tooth is more
interesting from the development point of
view than the maxillary canine”
• Canine develops in deepest area of maxilla
has the most tortuous course and longest path
of eruption (22mm) during its course or
eruption and has longest period of
development.
• During their course of development, the
crowns of the permanent canines are
intimately related to the roots of the lateral
incisors.

• A periapical view shows the unerupted
permanent canine crowns, of each side,
pointing mesially towards the lateral incisor
apical area - causing the apical convergence
of the incisor roots and the median diastema
doesn’t close completely.
• The permanent canine alters its relationship
as it moves downwards along the distal side
of the root of the lateral incisor, uprighting
the long axis of that tooth – it then becomes
more vertical as it progresses and as the root
of the deciduous canine becomes resorbed.

• With the shedding of the deciduous canine, it finally erupts with a
slight mesial inclination, taking up its place in the arch by moving
the crowns of the incisors towards the midline, to close off the
diastema completely.
• Throughout the period of its downward progress, the permanent
canine is conspicuously palpable on the buccal side of the alveolar
ridge, from as early as 2-3 yrs period to its normal eruption, which
normally occurs at the age of 11-13 yrs.

ETIOLOGY
• Becker Concept:
Becker (1984) hypothesized two processes in the palatal impaction of
the maxillary canine - Absence of initial early guidance from an
anomalous lateral incisor, and later failure of buccal movement of the
canine at an unspecified age {9 years}.
• Moyer’s etiology of Maxillary Canine Impaction (Multifactorial):
Bishara summarised Moyer's theory that the causative factors may be -
1. Primary (Localized)
(a) Tooth size-arch length discrepancies.
(b) Prolonged retention or early loss of deciduous canine.
(c) Abnormal position of the tooth bud (rotation of tooth buds).
(d) Trauma to the deciduous tooth bud.

(e) Disturbances in the tooth eruption sequence.
(f) Presence of an alveolar cleft.
(g) Ankylosis
(h) Cystic or neoplastic formation
(i) Dilaceration of the root
(j) Premature root closure
(k) Iatrogenic
(l) Idiopathic
2. Secondary (Generalised)
(a) Abnormal muscle pressure
(b) Febrile diseases
(c) Endocrine disturbances
(d) Vitamin D deficiency
(e) Irradiation.

• Berger Concept {Systemic cause of impaction}:
1. Malnutrition
2. Tuberculosis
3. Syphilis
4. Rickets
5. Anemia
6. Progeria
7. Syndromes:
a) Cleidocranial dysplasia
b) Achondraplasia
c) Down syndrome
• Vonder Heydt Concept:
Total arch length of permanent teeth is initially established very early in
life at the true of eruption of first permanent molars. Canine is larger
and later erupting and considering like a musical chair situation it may
get impacted.
Reason for eruption of canine labially is arch length deficiency.

MC Bridge Concept:
Canine formed at high in the anterior wall at antrum, below the floor
of orbit, its long tortous path of eruption is the reason for impaction.
Peck and Peck Concept:
Characteristics of palatally impacted canines include,
1) Occurrence of other dental anomalies - occurs in combination
with tooth agenesis, tooth size reduction, supernumery tooth
and other ectopically positioned tooth.
2) Bilaterally occuring Phenomenon (17%)
3) Females affected more than males (1:3.2)
4) Familial occurence
They concluded palatally impacted canine as dental anomaly of
genetic origin.

Guidance Theory – Miller:
Canines usually have a more mesial development path, which is guided
downwards apparently along the distal and aspect of the lateral incisor
roots.
- FIRST STAGE IMPACTION: If there is a loss of guidance due to missing
lateral incisors or late developing laterals, canines will have a mesial
and palatal path of eruption. In this event there is no vertical movement
of canine into the alveolar process, resulting in a more horizontal
impaction.
FIRST STAGE IMPACTION AND SECONDARY CORRECTION: Once it has
reached the palatal alveolar process, canine is redirected to a more
favorable path of eruption.
- SECOND STAGE IMPACTION: Self correction is prevented by, late
developing lateral incisors (peg laterals) which re-deflect the tooth
further palatally.
SECOND STAGE IMPACTION AND SECONDARY CORRECTION: Extraction of
deciduous canine or even extraction of lateral incisors leads to
spontaneous eruption of the impacted tooth.

LABIAL CANINE IMPACTION
In Arch length deficiency,
1. Canine will have contact with crown or root at lateral incisors, first
premolar and deciduous canine.
2. Canine is surrounded by anterior wall of maxillary sinus, and nasal
cavity.
So it is impossible for canine to jump in to or behind tooth or
penetrating to nasial cavity or sinus - impacted labially.
PALATAL CANINE IMPACTION
Canine can be palatally positioned if extra space available in maxillary
bone space due to,
1. Excessive growth in the base of maxillary bone
2. Agencies of lateral incisors
3. Peg shaped lateral incisors
4. Stimulated eruption of lateral incisors or 1st premolars.

SEQUELAE OF IMPACTION
• The normal sized and early developing lateral incisor root obstructs the
deviated eruption path of canine - damaged by resorption.
• Anomalous lateral incisors (peg shaped & or small mesiodistal crown
width) have small and late developing roots - more easily bypassed

CLASSIFICATION
Impacted canine
Maxillary canine Mandibular canine
Buccal Palatal Lingual
Buccal

IMPACTED CANINE
Horizontally Vertically
Palatal
Above
Labial
Mid- alveolar
Below
( With respect to the arch)
(With respect to the apex)
(JCO 1979 DEC)
• Classification by ACKERMAN and FIELDS (1935) -

• Class I:
Impacted cuspids located in palate.
a) Horizontal
b) Vertical
c) SemiVertical
• Class II:
Impacted cuspids located in Labial or buccal surface of maxilla
a) Horizontal
b) Vertical
c) SemiVertical
• Archer’s canine impaction classification -

• Class III:
Impacted cuspids located in palatine and maxillary bone e.g. crown
is on the palate and root passes through the root of the adjacent
teeth and ends in the labial or buccal surface of maxilla.
• Class IV:
Impacted cuspids located in the alveolar
process, usually vertically between incisor
and first bicuspids
• Class V:
Edentulous maxilla
• Class VI:
Aberrant position

• Classification of palatally impacted canine
• Based on two variables:
(1) Transverse relationship of the crown of the tooth to the line of
dental arch which may be -
(a) Close
(b) Distant (nearer the midline)
(2) Height of the crown of the teeth in relation
to the occlusal plane which may be
(a) High
(b) Low

• Group 1
 Proximity to the line of arch – close.
 Position in the maxilla – low.
• Group 2
 Position in the maxilla – forward , low & mesial to
the lateral incisor root.

• Group 3
 Position in the maxilla – high.
• Group 4
 Proximity to the line of arch – distant.
 Position in the maxilla – high.

• Group 5
Canine root apex mesial to that of lateral
incisor or distal to that of first premolar.
• Group 6
Erupting in the line of arch in place and
resorbing the roots of incisors.

DIAGNOSIS
IMPACTED OR PREMATURLEY ERUPTED?
• Gron(1962) stated that under normal circumstances a tooth erupts with a
developing root and with approx. three quarters of its final root length.
• The mandibular central incisors and first molars have marginally less
root development and mandibular canines and second molars marginally
more when they erupt.
• Thus should an erupted tooth have less root development, it would be
appropriate to label it as prematurely erupted.
• At the opp. end of the scale, we find the un-erupted tooth that exhibits a
more completed developed roots, the normal eruption process of this
tooth must be presumed to be impeded.

CLINICAL EVALUATION:
The following signs might be indicative of canine impaction.
1. Delayed eruption of the permanent canine or prolonged retention of
the deciduous canine beyond 14 to 15 years of age.
2. Absence of a normal labial canine bulge.
3. Presence of a palatal bulge.
4. Delayed eruption, distal tipping or migration(splaying) of the
lateral incisor.

RADIOGRAPHIC EVALUATION:
1. Periapical films:
The first, simplest and most informative X-ray.
- Advantages,
1) Root development, pattern and integrity
2) Crown resorption
3) Root resorption of adjacent tooth
4) Minimun of surrounding tissue is exposed which increases accuracy
and resolution.
5) Minimal radiation exposure
- Disadvantages,
1) Two dimensional representation which gives no information
regarding buccolingual plane
2) Overlapping structures cannot be differentiated as to which is lingual
and which buccal.

a) Tube Shift Technique
- Two periapical films are taken of the same area with the horizontal
angulation of the cone changed when the second film is taken. If the
object in question moves in the same direction as the cone - lingually
positioned. If the object moves in the opposite direction it is situated
closed to the source of radiation - buccally located.
- Disadvantage: In cases when canine is highly placed, and periapical
film shows no superimposition of canine with the roots of erupted tooth
or when superimposition is only in the periapical region, the result may
be misleading.

b) Buccal Object rule
If the vertical angulation of the cone is changed by approximately
20o in two successive periapical films, the buccal object will
move in the direction opposite to the source of radiation. On the
other hand, the lingual object will move in the same direction as
the source of radiation. The basic principle of this technique
deals with the foreshortening and elongation of the images of the
films.

2. Occlusal films
- To determine the buccolingual position of the impacted canine
(provided the image of the impacted canine is not superimposed on the
other teeth)
- In this view the central ray of X-ray beam runs parallel to long axis of
central incisors. Exposure is done through the vertex i.e 110º to the
occlusal plane.
- When the radiograph is viewed the anteriors are seen as small tiny
concentric circles. If the impacted tooth is not parallel to neighbouring
tooth, depend on angulation of long axis of the tooth it will be elliptical
or oblique in cross section.
- If tooth is horizontal, its full length will be seen.

3. Extra Oral films:
- Frontal and lateral cephalograms for
determining the position of the impacted
canine, particularly its relationship to other
facial structures (eg. Maxillary sinus and the
floor of the nose)
- Panoramic films to localize impacted teeth in
all 3 planes of space (much the same as with 2
periapical films in the tube shift method, with
the understanding that the source of radiation
come from behind the patient , thus the
movements are reversed for position)

- In OPG, when mesiodistal width of canine crown was 1.5 times larger
(i.e. 15% larger) than the adjacent central incisor, then the canine is
palatally placed.
- This is only true in cases where canine should not be at a higher level.
[Reliability of a method for localisation of displaced maxillary canines using a
single panoramic radiograph. Chaushu et al; clin orthod res 1999; 2: 194-9]

4. CT Scanning:
- Clear radiograph can taken at graduated depth in any part of the human
body. By viewing serial radiograph slices of the maxilla, the relationship
of the impacted tooth to adjacent teeth in all the three plane of space can
be accurately assessed.
- Root resorption can be assessed.
- Superimposition of structures doesn’t obscure the image.
Disadvantage: Expensive, large dose of radiation to be justified.

5. Rapid prototyping:
- Comprises several technologies that
use data from computer-aided design
files to produce physical models and
devices by a process of material
addition.
- This made possible the fabrication
of an attachment for forced canine
eruption.
- Rapid prototyping dental modeling
might become the diagnostic
procedure of choice in the evaluation
of impacted maxillary canines

• Ericson and Kurol in EJO 1988 defined number of
sectors to denote different types of impaction -
i. Sector 1: if the cusp tip of the canine is
between the interincisor 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;
iii. Sector 3: if the peak of the cuspid of the canine
is between the major axis of the lateral and the
first premolar.
RADIOGRAPHIC PREDICTION

• They used angle “α” to represent the angle formed between the
interincisor midline and long axis of canine.
 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°.
 The duration of treatment is longer if the canine is found in sector
1, shorter if it belongs to sector 3, with respect to sector 2.
 The necessity of treatment and the degree of treatment difficulty
increases as this angle increases.

• Modification of Ericson & Kurol’s definition of sectors used:
i. Sector I: Located distal to a tangent to the distal crown & root of the
lateral incisor.
ii. Sector II: The area from the tangent on the distal surface to a midline
bisector of the lateral incisor tooth.
iii. Sector III: The area from the midline bisector to a tangent to the
mesial surface of the lateral incisor crown & root.
iv. Sector IV: All areas mesial to sector III.
Steven Lindauer et al. JADA March 1992. Canine Impaction identified early with
Panoramic Radiographs

• Study done by Stivaros and Mandall to investigate the radiographic
factors that influence the orthodontists decision to expose align or
remove an impacted tooth panoramic radiographs. (JO 2000)

1. Canine angulation to the midline
- Grade 1: 0–15°
- Grade 2: 16–30°
- Grade 3: >31°
2. Vertical Canine Crown Height
- Grade 1: Below the level of the CEJ
- Grade 2: Above the CEJ, but less
than half way up the root.
- Grade 3: More than half way up the
root, but less than the full root length.
- Grade 4: Above the full length
of the root.

3. Position of Canine Root Apex Antero-
posteriorly
- Grade 1: Above the region of the canine
position.
- Grade 2: Above the upper first premolar
region.
- Grade 3: Above the upper second premolar
region.
The vertical height from canine tip to the
occlusal plane ( > 15mm - poor prognosis).
4. Canine Overlap of the Adjacent Incisor
Root
- Grade 1: No horizontal overlap.
- Grade 2: Less than half the root width.
- Grade 3: More than half, but less than the
whole root width.
- Grade 4: Complete overlap of root
width or more.

PROGNOSIS
• Before the treatment decision was made, a number of diagnostic
patient and radiographic factors would have to be considered
including:
(1) Patient age - The upper age limits suggested for successful
alignment of an ectopic canine include 16 (McSherry, 1996) and
20 (Nordenram, 1987) years of age.
(2) General dental health and oral hygiene
(3) Whether space is available in the arch or can be made available
for alignment of the permanent canine - In 85 per cent of subjects
with palatal displacement of a canine there is adequate space in
the arch (Jacoby, 1983), whilst in crowded arches the canine is
more likely to erupt in a buccal position (Oliver et al., 1989).

(4) Suitability of the first premolar to replace a permanent canine
(5) Patient motivation for orthodontic appliances
(6) Medical contra-indications for surgery.
(7) Position of canine –
 As canine angulation to the midline
increases so does the likelihood of
removal rather than attempted
alignment.
 Palatally impacted canines more
likely to be exposed, and those in
the line of the arch or buccally
positioned more likely to be
removed (increased problems of
managing the attached gingivae)
 Higher above the occlusal plane the
canine is positioned, the poorer the
prognosis for alignment

PREVENTION OF MAXILLARY
CANINE IMPACTION
• When the clinician detects early signs of ectopic eruption of the
canines, an attempt should be made to prevent their impaction and its
potential sequelae.
• Selective extraction of the deciduous canines as early as 8 or 9 years of
age has been suggested by Williams as an interceptive approach to
canine impaction in Class I uncrowded cases.
• Ericson and Kurol suggested that removal of the deciduous canine
before the age of 11 years will normalize the position of the ectopically
erupting permanent canines in 91% of the cases if the canine crown is
distal to the axis of the lateral incisor. Success rate is only 64% if the
canine crown is mesial to the midline of the lateral incisors.

• Vertical canine angulation exceeding 31° relative to the midline
decreased success rates significantly.
• After extraction of the primary canines only 65% of the palatally
displaced canines have been found spontaneously erupted.
• The success rate would improve to 88% by the addition of forces to
prevent mesial migration of the maxillary posterior teeth after
extraction, i.e., the use of cervical-pull headgear.

(1) If it is ankylosed and cannot be transplanted
(2) If it is undergoing external or internal root resorption
(3) If its root is severely dilacerated,
(4) If the impaction is severe (e.g., The canine is lodged between the
roots of the central and lateral incisors and orthodontic movement will
jeopardize these teeth)
(5) If the occlusion is acceptable, with the first premolar in the
position of the canine and with an otherwise functional occlusion with
well-aligned teeth
(6) there are pathologic changes (e.g., cystic formation, infection), and
the patient does not desire orthodontic treatment.
EXTRACTION OF IMPACTED CANINES

TREATMENT ALTERNATIVES
1. No treatment if the patient does not desire it. In such a case, the
clinician should periodically evaluate the impacted tooth for any
pathologic changes but long term prognosis for retaining the
deciduous canine is poor, regardless of its present root length and
the esthetic acceptability of its crown.
2. Auto transplantation of the canine. Due to a high possibility of
pulp necrosis, endodontic treatment of fully developed transplanted
teeth should be undertaken. Recipient socket should be prepared to a
size that is slightly larger than the root of the donor tooth.
3. Extraction of the impacted canine and movement of a first
premolar in its position.

4. Extraction of the canine and posterior segmental osteotomy to
move the buccal segment mesially to close the residual space, which
is a tedious surgical procedure.
5. Prosthetic replacement of the canine, not amenable for juvenile
patients.
6. Transalveolar transplantation of maxillary canines was reported by
Soren Sagne et al., in AJODO ’86 - during this procedure it is
important to minimize trauma to the tooth, remove a great amount of
bone, to loosen the tooth gently from its impacted positions and not to
force it into its new site with hard bone contact.
7. Surgical exposure of the canine with/without orthodontic treatment
to bring the tooth into the line of occlusion - most desirable approach.

GENERAL PRINCIPLES OF
MECHANO-THERAPY
• Leveling and Alignment of the
erupted teeth.
• Creating enough space for the
impacted canine and maintaining it.
• Conversion of the arch into a rigid
anchorage unit.
• Surgical exposure of the crown of the
impacted canine and attachment
bonding.
• Application of low force (60gm)
traction from rigid anchorage unit.

METHOD OF CREATING SPACE
A) Existing incisor space -
Becker showed incisor spacing was due to
failure of completion of ugly duckling
stage of development. During final stage
these existing spaces will be closed by
mesial movement of lateral incisor.
B) Improving arch form -
Improving arch form after extraction of
deciduous canine will add 2-3 mm of
space.

C) Increasing arch length -
In mild crowding cases distalization of molar is recommended which
increases the arch length.
D) Extraction as means of prevention (Mixed dentition period) -
i. Deciduous canine
Patient with age of 10-13 years with delayed dental age, palatal
displacement of canine with apex confirmed in line of arch requires
extraction of deciduous canine for good prognosis for eruption of
permanent canine.

ii. First Premolar
I) Crowding of maxillary arch
II) Bimaxillary protrusion
III) Class II relation
iii. Lateral Incisor
Peg shaped or severely malformed lateral incisor (dens invaginatus) can be
extracted instead of healthy premolars.
iv. Central Incisor
When there is advanced resorption of central incisor roots more than 23rd
and canine erupting close to the long axis of the incisor, extraction of
incisor is indicated.

• Micro implant anchorage
- The microscrew should be placed in the labial cortical alveolar
bone, at an angle of 10-20° to the bone surface and as parallel to the
tooth's long axis as possible.
- This keeps the apex of the microscrew on the buccal side and
reduces the likelihood of its contacting the root.
- The head of the microscrew should be located as incisally as
possible to maximize the vertical component of force.

ANCHORAGE CONSIDERATION AND
SPACE MAINTENANCE
• Use of full dimension stainless steel
rectangular wire in edgewise brackets.
• Use of 0.022 / 0.020 wires with
uprighting springs or torquing springs to
act as brakes if necessary in beggs and
tip-edge appliance.

• Mandibular Anchorage
- Lingual arch is fabricated with
0.036 inch SS wire
- Vertical hooks (5-6mm in length)
- Elastic force should not exceed 40-
60 gm
Advantages
- Simplicity in appliance design and
application
- Reduced overall treatment time

SURGICAL METHODS
The goal is to choose a technique that exposes the canine within the
zone of keratinized mucosa without involvement of CEJ.
1. Surgical exposure with spontaneous eruption
2. Surgical exposure with packing only – prevent rehealing in deep
impaction cases predicting spontaneous eruption
3. Surgical exposure with packing and delayed bonding of an
auxiliary – when spontaneous eruption fails, attachment can be
bonded under direct vision after 1 week post-op (2-step technique)
4. Open eruption technique
5. Closed eruption technique

SURGICAL EXPOSURE TO ALLOW
NATURAL ERUPTION
• Useful when the canine has a correct axial inclination and does not need
to be uprighted during its eruption.
• Clark recommended that a polycarbonate crown be placed over the
impacted tooth after its surgical exposure.
• The crown should be made long enough to extend through a window
cut in the palatal tissue.
• Often, 6 months to 1 year may elapse before the impacted tooth has
erupted sufficiently to permit removal of the polycarbonate crown and
its replacement with an orthodontic attachment.
• If the tooth fails to erupt, clark recommends the removal of any tissue
surrounding the crown.
Clark D. The management of impacted canines: free physiologic eruption. J Am Dent Assoc 1971;82:836-40.

ONE STEP VS TWO STEP
Two approaches are generally recommended with regard to the timing
of placing the attachment.
1. Two-step approach: Canine is surgically uncovered and the area is
packed with a surgical dressing to avoid the filling in of tissues around
the tooth. After 3 to 6 weeks, the pack is removed, and an attachment is
placed on the impacted tooth.

2. One-step approach: attachment is
placed on the tooth at the time of
surgical exposure and a periodontal
pack placed.
- The pack minimizes patient
discomfort and prevents the
granulation tissues from covering
the attachment.
- Recommended for palatably
impacted teeth.
Advantages - the clinician is able to
visualize the crown of the tooth and to
have better control over the direction of
tooth movement, prevents moving the
impacted tooth into the roots of the
neighboring teeth.

TYPES OF FLAPS FOR
IMPACTED CANINE
Labially impacted tooth
1. A circular incision - done by removing mucosa over the crown to
expose the impacted tooth.

Advantages:
a) Easy to perform
b) Suitable access can be provided for bonding of the attachment
c) Reduction of impaction is rapid.
Disadvantages:
a) Tooth will be invested on labial side with thin oral mucosa
rather than attached gingiva.
b) Typical soft tissue contour aggravates plaque accumulation
which leads to gingivitis.
Inflammation will prevent regeneration of the periodontal ligament
which leads to apical movement of the epithelial attachment.

2. Apically repositioned surgical flap –
A split thickness pedicle reflected from the edentulous area.
i. Incisions extend vertically into the vestibule and split thickness
flap is reflected.
ii. Bone covering the enamel is removed.
iii. Two thirds of the crown exposed, and the connective tissue
follicle, curetted from the periphery of the exposed portion of the
crown.
iv. The flap is sutured to the periosteum, leaving one half to two
thirds of the crown uncovered.
v. A surgical dressing is placed on the enamel to prevent overgrowth
of the adjacent tissue.
vi. The dressing is removed 1 week, post operatively and the
attachment placed on the uncovered tooth.

Advantages:
a) Maintain the width of attached gingiva
b) Easy access for bonding of the attachment
c) Tooth can be visualized from the time of exposure till it comes to
occlusion
Disadvantages:
a) Uneven and unesthetic gingival margin
b) Increased Clinical crown length
c) Some degree of attachment and bone loss on the labial surface,
which was considered as possibly related to an increased potential
for plaque accumulation.

3. Full flap closure –
- A full buccal surgical flap is raised to expose the canine, an
attachment is bonded to the tooth and the flap is sutured back to its
former place itself.
- A twisted thread is tied to the bonded tooth and then drawn inferiorly
and through the sutured ends of the replaced flap, through the crest of
the ridge or through the socket vacated by the extracted deciduous
canine.

Advantages:
a) Tooth can be erupted towards and through the attached gingiva which
maintains the width of the attached gingiva
b) No gingival scarring and good periodontal attachment is established
c) No vertical relapse
d) Conservative bone removal
e) Immediate traction possible
f) Less discomfort and good post
operative haemostasis

Disadvantage:
a) Placement of the bonding attachment is necessary at the time of exposure
b) If there is a bond failure it needs re-exposure
c) Difficulty in gaining dry field
d) Buttonholing: due to buccal prominence of the tooth, lack of buccal
bone and relative tightness of the replaced flap, damage to the
mucogingival tissue is due to the bulk of wide and high profile bracket,
which may leads to a breakdown of the overlying tissue causing dehiscence

Palatally impacted tooth
1. Closed technique –
- The canine was surgically uncovered with a full-thickness
mucoperiosteal flap dissected off the bone.
- The bone covering the canine was removed with a punch or bur;
NaCl irrigation.
- Attachment with a chain was bonded to the exposed tooth.
- Swab gauze 1.5 × 1.5 cm and tranexamic acid (Cyklokapron 5%)
could be used to get a dry operation field.
- The palatal flap was repositioned and sutured back with the chain
extending through an incision in the palatal flap.

2. Open technique –
- The canine is surgically uncovered with a full-thickness mucoperiosteal
flap dissected off the bone.
- The bone covering the canine is removed with a punch or bur; NaCl
irrigation.
- Polyacrylic acid and then conventional, light cured glass ionomer
cement are applied on the surface of the crown of the impacted canine,
to the level of intact mucosa.
- Swab gauze 1.5 × 1.5 cm and tranexamic acid (Cyklokapron 5%) could
be used to get a dry operation field.
- The palatal flap is repositioned and sutured back, and a window of
mucoperiosteal tissue overlying the tooth was removed with a punch or
a scalpel.

ATTACHMENTS
1. Lasso wires: It is twisted lightly around the
neck of the canine.
Disadvantages:
₋ Irritation of the gingiva
₋ Poor control over direction ofmextrusion
₋ Prevents reattachments of the healing tissues in area of CEJ
(cemento-enamel junction).
₋ May produce areas of external resorption & ankylosis in
areas of CEJ.
So, it is rarely used now.

2. Threaded Pins: Provides the attachment for an
impacted tooth.
Disadvantages:
- Dentaly invasive.
- Requires a subsequent restoration.
- Difficult to place along the long axis
of the tooth because of smaller surgical exposure.
- The drilled hole may inadvertently enter the
pulp(unerupted teeth may have large pulp chambers).
Also rarely used.

3. Orthodontic bands:
They largely replaced the
lasso wires & threaded pins.
Advantage:
They are compatible with the health of periodontal tissues.
Disadvantage:
- Large surgical field required.
- Requires extensive bone removal
- Inadequate moisture control may hamper with the cement-band bond.

4. Standard orthodontic brackets:
Any edge-wise, Begg’s, PAE brackets
can be used with composite.
Disadvantages:
- As the bracket base is wide, it is difficult to adapt to any other tooth
surface except for the buccal surface.
- The bracket’s shear bulk creates irritation as the tooth is drawn the soft
tissues.
- Interferes with the investing tissues & leads to inflammation &
periodontal damage.
- As the impacted tooth advances into the arch the exuberant gingival
tissues bunches in front of it & causes punching between the bracket &
tissues.

5. A simple eyelet:
Advantages:
- An eyelet welded to band material with a mesh
backing is soft & easy to contour - adaptation to
bonding surface more accurate - superior retentive
properties.
- Because of small size they can be placed in more
awkwardly placed teeth.
- Less irritating to the surrounding tissues.

6. Elastic ties and modules:
Advantages
- Application of light forces
- Good range of action
- Easier to tie
Disadvantages
- Tends to loosen
- High degree of force decay

7. Magnets:
It is made up of rare earth lanthanide
alloys .
Disadvantage - corrosion.
8. Cast Canine Cap:
Requires extensive crown preparation
9. Lingual button with ligature
chain or gold chain:
Most commonly used.

METHODS OF TRACTION
1. Active palatal arch
(Becker1978)
• It consists of a fine 0.020 inch removable
palatal arch wire carrying an omega loop on
each side.
• End of the wire is doubled for frictionless
fit in lingual sheath.
• It is activated by downward activation of
palatal arch wire and hooking the pigtail
ligature around it.

2. Light Auxiliary Labial Arch
(Kornhauser1996)
• Fabricated with a 0.014" round SS,
formed in a archform with a loop
having a small helix.
• Wire is tied with the basal
arch wire in piggyback
fashion.
• If a basal arch wire is not used
it will leads to extrusion of
adjacent tooth and cause
alteration of occlusal plane.

3. TMA Box Loop
• TMA .017 X .025 wire used.
• Produces sagittal and horizontal
corrections while continuing vertical
eruption.
• Used in select cases.
Alignment of Impacted Canines with Cantilevers and Box Loops;
Surendra Patel; JCO 1999 volume 33 : 2 : 82-85

4. Cantilever Spring
• TMA .017 X .025 wire used
• Initial extrusion mechanics with
a cantilever.
• Use of a box loop to continue
canine extrusion and to make
1st- and 2nd-order corrections.
• Incorporation of the canine into
a continuous archwire for finishing.
• The reactionary force and the
moment are dissipated on the molar,
which can be controlled by using a
palatal arch and or ligating the molar
to the rest of the arch.

5. Australian Helical Archwire
• Made in special plus .016” arch wire
• Activation by twisting the steel ligature wire every
two weeks.
• The Australian wire is bent with helices that serve as
stops against the brackets of the adjacent teeth to
maintain space for the erupting canine.
• An additional incisal helix increases the resilience of
the system and anchors the SS ligature running to the
canine attachment.
• The force vector for canine can be altered by
changing the transverse position of the incisal helix.

6. Two Archwire Technique
• Surgical procedure involves apically positioned flap for superficial
impaction and full thickness mucoperiosteal flap with a crestal
incision for deeper impactions.
• Orthodontic procedure consists of placement of preadjusted 0.022 x
0.028 brackets.
• An 0.014" NITI arch wire is cut so that it passes through 2 or 5
brackets on either side of impacted tooth.
• Eyelet chain activated every 4 - 6 weeks.

7. Piggy-back technique:
• Consists of double wires (auxiliary and base wire), the auxiliary wire -
segmented or continuous.
• Rigid stainless steel base archwires with significantly higher elastic
modulus, e.g. 0.018-inch or 0.019X0.025- inch SSW, are preferred to
limit unwanted effects on anchor units and an auxiliary super elastic
NiTi (including thermal NiTi) archwire of 0.012- inch or 0.014-inch
to continue the eruptive process of tooth.

• Advantages
- Relatively constant, light force with high flexibility and range allowing
engagement of significantly displaced teeth.
- Realigning of the teeth avoided.
- Reciprocal forces reduced – single archwire affects the other teeth in
the arch - an iatrogenic open bite, canted occlusal plane, crossbite, etc.
• Disadvantage
- Increased friction due to the doubled archwires.

8. The K-9 Spring
• Designed by Dr.Varun Kalra
• The K-9 is made of 0.017" x 0.025" TMA
• The TMA can be activated twice as far as
stainless steel before it undergoes permanent
deformation, while producing less than half
the force.
• Designed on the principle of reciprocal
torqueing.
• To activate the spring after it is engaged in
the buccal segment, the vertical arm is swung
upward and ligated to the bonded attachment
on the canine.
• The force needed to distalize the canine is
achieved by inching the spring back about
2mm after it has been ligated to the canine.

9. Ballista Spring (Jacoby 1979)
• A ballista loop is a simple, convenient, unobtrusive method of applying
a vertical vector of force to a palatally impacted tooth to erupt the
crown into the center of the alveolus.
• Exposure of the crown facilitates attachment of an elastomeric chain
directed toward the center of the edentulous alveolar ridge to gradually
guide the canine crown into the dental arch.

• 0.018-inch continuous SS archwire used to form the spring.
• The impacted tooth is retracted by a spring that accumulates a
continuous force from being twisted on its long axis.
• With this technique, the crown typically erupts into the center of the
alveolar ridge, similar to a naturally erupting tooth.

10. Kilroy Spring (2003)
• A constant force module of .016SS
that delivers slow and continuous
force on a rectangular archwire.
• In the passive state, the vertical
loop of the Kilroy Spring extends
perpendicularly from the occlusal
plane.
• To activate the spring, a stainless
steel ligature is guided through the
helix at the apex of the vertical
loop, and the loop is directed
toward the impacted tooth.
• The ligature is then tied to an
attachment that has been direct-
bonded to the surgically exposed
tooth

• The amount of force generated by the Kilroy Spring can be
increased or decreased by bending the vertical loop toward or
away from the impacted tooth.
• The direction of force is also adjustable.
• Because of the inherent flexibility in its design, the Kilroy
Spring will typically fit the available arch space whether the
final destination of the impacted tooth is wider or narrower than
the tooth itself.
• The vertical loop of the Kilroy Spring can be adjusted to
produce a light force to assist in closing, maintaining, or
opening space.

11. Kilroy II Spring
• Designed to produce more vertical than lateral eruptive forces for
eruption of buccally impacted teeth.
• Its multiple helices increase its flexibility, but also increase the
likelihood of impingement on the soft tissue.
• More frequent progress checks are recommended

12. Modified Kilroy Spring
• The modified Kilroy I Spring that can be
applied without removal of the deciduous
canine, thus improving the patient’s esthetic
appearance and helping to maintain the canine
space.
13. The Monkey Hook
• It is a simple auxiliary with an open loop on
each end for the attachment of intra oral elastic
or elastomeric chain or for connecting to a
bondable loop button.
• A combination of monkey hooks and bondable
loop-buttons allows the production of a variety of
different direction force such as

14. Tunnel - Traction of Infraosseous Impacted Maxillary Canines
• Deep infraosseous canines associated with persistent deliduous teeth
may be successfully and safely treated by repositioned flap and tunnel
traction toward the center of the alveolar Ridge.
• Cortical bone removed to provide access to crown and button bonded
with ligature chain.
• The chain passes through the bone tunnel and emerges from the
socket of the deciduous tooth.
• Traction phase started after one week when sutures are removed and
directed to the center of the alveolar ridge.
Advantages
- No attachment loss and no recession are observed
at the end of active therapy or 3 years later.

• Not much is present in literature about mandibular canines as its
occurrence is a rare condition.
• For lingually placed canine, attachment has to be bonded on buccal
surface only, buccal surgical exposure preferred.
MANDIBULAR CANINE IMPACTION

ROOT RESORPTION AND
CANINE IMPACTION
• Resorption of roots stops when canine
impaction has been solved.
• Subsequent orthodontic movement of
resorption affected teeth does not generate
further resorption.
• Incisors with severely resorbed roots have
high survival rate.
• Teeth remain vital, and retain their color,
and appearance.
• Teeth show very low degree of mobility
and an improvement in periodontal bone
support following post treatment retention.
• Splinting is not usually necessary.
Long-term follow-up of severely resorbed maxillary
incisors after resolution of an etiologically associated
impacted canine. Adrian Becker; AJODO
2005;127:650-4

IMPACTED CANINE AND
PERIODONTIUM
• A study was done to evaluate the periodontal health and tooth vitality
of palatally impacted and buccal ectopic maxillary canines after
completion of orthodontic treatment.
• Conclusion: All ectopic canines had increased plaque and gingival
bleeding index, greater pocket depths, reduced attached gingival
width, higher gingival levels, increased crown lengths, higher electric
pulp testing scores, and reduced bone levels compared to their
contralaterals.
Periodontal status of ectopic canines after orthodontic treatment. AO 2014 Aysegu lDalkılıc¸ Evrena S¸ Irin Nevzatog,
Tulin Arunc Ahu

RETENTION
• To minimize rotational relapse, options available are -
1. Fiberotomy
2. Bonded fixed retainer
• Clark’s suggestion for palatally impacted canine:
Lingual drifting can be prevented by removal of half moon-shaped wedge
of tissue from lingual aspect of canine.
• Becker et al. evaluated the posttreatment alignment of the impacted
canines in patients who had completed their orthodontic treatment.
They observed an increased incidence of rotations or spacings on the
"impacted" side in 17.4% of the cases, whereas on the control side the
incidence was only 8.7%. The control side had ideal alignment twice as
often as did the impacted side.

• Devitalization, ankylosis or loss of vitality, recurrent pain, cystic
degeneration, invasive servical root resorption, external root
resorption of the canine and adjacent teeth may be seen.
• Loss of periodontal bone support, gingival recession, sensitivity
problems or combinations of these factors may be observed.
• No movement of the impacted canine is observed,
- inappropriate positional diagnosis of the impacted teeth and its
relationship with the roots of the adjacent teeth
- a lack of considerably anchorage requirement will lead to inefficient
mechanotherapy and unnecassarily longer treatment
- anyklosis might have afflicted the impacted tooth either a priori or as
the result of the earlier surgical or the orthodontic maneuers.
- scar tissue might have blocked the wire chain
COMPLICATIONS OF TREATMENT

COMPLICATIONS OF UNTREATED
IMPACTED CANINE
1) Crown resorption followed by replacement resorption - resorption of
enamel and its replacement by bone
2) Labial or lingual malposition of impacted tooth
3) Migration of neighboring teeth and loss of arch length
4) Internal resorption of impacted tooth
5) Cyst formation (Dentigerous cyst)
- Potential complications of dentigerous cyst,
a) ameloblastoma
b) Epidermoid Carcinoma
c) MucoEpidermoid carcinoma
6) Resorption of lateral incisor root

CONCLUSION
• The management of impacted canines is important in terms of esthetics
and function and, requires a qualified experience of a number of
clinicians.
• Various surgical and orthodontic techniques may be used to uncover
impacted maxillary canines related to its position.
• Accurate localization, conservative management of the soft tissues,
selection of appropriate surgical approach, rigid anchorage unit, and the
direction of the orthodontic traction are the important factors for the
successful management of impacted canines.

• Adrain Becker, Orthodontic treatment of Impacted Teeth, Third edition
• Kumar, S. (2015). Localization of Impacted Canines. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH.
• Stivaros, N., & Mandall, N. A. (2000). Radiographic Factors Affecting the Management of Impacted Upper
Permanent Canines. Journal of Orthodontics, 27(2), 169–173.
• Reliability of a method for localisation of displaced maxillary canines using a single panoramic radiograph.
Chaushu et al; clin orthodres 1999; 2: 194-9
• Early treatment of palatally erupting maxillary canines by extraction of the primary canines. Ericson S. & Kurol
J.; European Journal of 161 Orthodontics 1988;10: 283-295
• Prediction of maxillary canine impaction using sectors and angular measurement. Warford J. Jr et al AJO-DO
2003; 124(6): 651-655
• Localization of Impacted Canines: A Review. Kumar S. Journal of Clinical and Diagnostic Research 2015; 9(1)
• Vishnoi P, Keshubhai KJ, Surendra SS, Bandi N, Jingar J, Rutvik T. Maxillary Canine Impactions: Orthodontic
and Surgical Management. Ann. Int. Med. Den. Res. 2016;2(3):2-10.
• Clark D. The management of impacted canines: free physiologic eruption. J Am Dent Assoc 1971;82:836-40.
• Uncovering labially impacted teeth: apically positioned flap and closed eruption technique. Vermette et al; AO
1995; 65: 23-32.
• Shapira Y, Kuftinec MM. Treatment of impacted cuspids: the hazard lasso. Angle Orthod 1981; 51: 203–207.
• Alignment of Impacted Canines with Cantilevers and Box Loops; Surendra Patel; JCO 1999
• Incisor Root Resorption Due to Ectopic Maxillary Canines A Long-Term Radiographic Follow-Up Babak Falahat;
Sune Ericson; Rozmary Mak D’Amico; Krister Bjerklin Angle Orthodontist, Vol 78, No 5, 2008
• Periodontal status of ectopic canines after orthodontic treatment. AO 2014. Ays¸egu¨ l Dalkılıc¸ Evrena; S¸ irin
Nevzatog˘ lub; Tu¨ lin Arunc; Ahu Acard
REFERENCES

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