Management of impacted canine

 Introduction
 Devolpment of canine
 Incidence of canine impaction
 Etiology of canine impaction
 Classification
 Sequelae of canine impaction
 Diagnosis
 Prognosis
 Prevention
 Treatment alternatives
 Periodontal considerations
 Attachments
 Mechanotherapy
 Conclusion www.indiandentalacademy.com

INTRODUCTION
 Ectopic eruption and impaction of maxillary permanent
canine is a frequently encountered clinical problem.
 IMPACTION is the Greek word derived from IMPACTUS.
 DEFINITION ;-
 A tooth whose roots are 2/3 or fully developed but
neverthless expected to erupt.
 Canine impaction is next common to mandibular third molar
impaction. Mandibular second premolar is second to
maxillary canine impaction
www.indiandentalacademy.com

DEVELOPMENT 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
longest path of eruption, travels 22mm during its
course or eruption and has longest period of
development.

 Develops at 30th
week (i.u.l)
 Calcification ;- begins around 4 - 5 months of age
 Eruption ;- left behind the roots of deciduous
molar
 Around 6 -7 years of age calcification will be
completed.

INCIDENCE OF CANINE IMPACTION
• Dachi and Howell (1961) incidence of maxillary canine
impaction - 0.92% .
• Ericson and Kurol (1986) - 1.7%
• Johnston et al (1982) – greater incidence of palatal
impaction than the labial
• Gaulis and Joho (1982) -2:1 ratio of palatal to buccal
impaction.
• Of all patients with maxillary impacted canines, 8% have
bilateral impactions & twice as common in females (1.7%)
than in males (0.51%)www.indiandentalacademy.com

ETIOLOGY OF IMPACTED CANINE
MOYER’S CONCEPT SUMMARISED BY BISHARA
Primary causes
A. Decreased rate of root resorption of deciduous teeth.
B. Trauma of deciduous tooth bud.
C. Disturbance in tooth eruption sequence.
D. Availability of space in the arch .
E. Premature root closure.
F. Canine eruption into the cleft area in cleft palate cases.
- Bishara & associates

Secondary causes
A. Abnormal muscle pressure.
B. Febrile disease.
C. Endocrine disease
D. Vitamin D deficiency.
E. Irradiation
- Bishara & associates

ETIOLOGY
 BECKER CONCEPT (1984)
 MCBRIDGE CONCEPT
 BERGERS CONCEPT
 VONDER HEYDT CONCEPT
 PECK AND PECK CONCEPT

GUIDANCE THEORY BY MILLER
NORMAL ERUPTION;- TIMELY AND NORMAL DEVLOPMENT
OF A LATERAL INCISOR AND GUIDANCE FOR CANINE IS
PROVIDED
FIRST STAGE IMPACTION ;-
 LOSS OF GUIDANCE AT A CRITICAL TIME IN THE NORMAL
DEVLOPMENT OF THE PERMANENT CANINE, WHICH LEADS
TO DEFLECTION OF DEVLOPMENTAL PATH OF THE TOOTH,
CAUSING IT TO MOVE PALATALLY

 FIRST STAGE IMPACTION WITH SECONDARY
CORRECTION ;-
 IT GOES ON TO EXPLAIN THE CORRECTIVE
INFLUENCE OF THR VERTICAL ALVEOLAR
PROCESS, WHICH REDIRECTS THE CANINE ON A
MORE FAVOURABLE PATH.
 SECOND STAGE IMPACTION ;-
 SELF CORRECTION IS PREVENTED BY PRESENCE OF
LATE DEVELOPING LATERAL INCISOR,
REDEFLECTING THE TOOTH FURTHER PALATALLY
 SECOND STAGE IMPACTION AND SECONDARY
CORRECTION ;-
 EXTRACTION OF DECIDUOUS CANINE OR EVEN
LAT.INCISOR MAY OFTEN LEAD TOSPONTANEOUS
ERUPTION OF IMPAC.TOOTHwww.indiandentalacademy.com

CLASSIFICATION OF IMPACTED CANINE
Impacted canine
Maxillary canine Mandibular canine
Buccal Palatal LingualBuccal

Classification by ACKERMAN and FIELDS in 1935.
IMPACTED CANINE
Horizontally vertically
Palatal
Above
Labial
Mid- alveolar
Below
( With respect to the arch)
(With respect to the apex)
(J CO 1979 DEC)

Classification of palatally impacted canine
The classification is 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 www.indiandentalacademy.com

Group 1 - Proximity to the line of arch – close.
- Position in the maxilla – low.
Position in the maxilla – forward , low &
mesial to the lateral incisor root.
- 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 of and resorbing
the roots of incisors.

CLASSIFICATION BY ERICSON AND
KUROL (AJO 1988)

SEQUELAE OF IMPACTION
• Labial or lingual malposition of the
impacted tooth.
• Migration of the neighbouring teeth
and loss of arch length.
• Internal resorption.
• Dentigerous cyst formation.www.indiandentalacademy.com

• External root resorption of the
impacted tooth, as well as the
neighbouring teeth.
• Infection particularly with partial
eruption.
• Referred pain.
• Combination of the above sequelae.

CLINICAL RADIOGRAPHIC

CLINICAL METHOD FOR
DIAGNOSIS
o Delayed eruption of permanent canine.
o Prolonged retention of deciduous canine.
o Absence of normal labial canine bulge.
o Presence of palatal bulge (Abnormal).
o Delayed eruption, distal tipping or migration of lateral incisor.

RADIOGRAPHIC METHOD FOR DIAGNOSIS
In Orthodontic treatment planning, the exact localization of
the position of an impacted canine is necessary.
Periapical
Max. ant. occlusal True vertex/occlusal
OPG Lateral ceph
Extraoral
I. Qualitative radiographs
Maxillary arch Occlusal
PA view

Parallax method
II. 3-D diagnosis of the position
C T scanning
Radiographic views at right angles

PERIAPICAL RADIOGRAPH

Periapical Radiography-
• Are the simplest and the most informative X-ray films.
• As this view passes through minimum of surrounding
tissues, it gives accuracy & quality of resolution.
• It is aimed to be perpendicular to an imaginary plane
bisecting the angle between the long axis of an erupted
tooth and the film plane to produce minimum distortion.

The periapical film gives the following information:
[1] Presence or absence of impacted tooth.
[2] Stage of development.
[3] Presence & size of follicle.
[4] Indicates crown or root resorption, resorption pattern
& integrity.
[5] Indicates presence or absence of supernumerary tooth.
[6] Indicates soft tissue lesions like cysts.

OCCLUSAL RADIOGRAPH
1.Maxillary anterior occlusal
• In the maxillary arch, the nose and forehead interfere with
the positioning of x-ray tube close to the area to be viewed.
• The best that can be achieved by positioning the tube close
to the face,so that it becomes high and steeply angled view.

2. Ture vertex / occlusal
• A true vertex view is one which passes parallel to the long
axis of central incisors.This is possible if the cone is placed
over the vertex of the skull to produce vertex occlusal film.
• Since the beam has to travel a great distance there is loss of
clarity. www.indiandentalacademy.com

OCCLUSAL
RADIOGRAPH

Extraoral Radiography:
• OPG has the advantage of simplicity & quickly
offering a good scan of the teeth & jaws from
Temporomandibular joint to Temporomandibular joint.

• True lateral extraoral view is also used for localization
of impacted teeth, however the results are misleading.
• True P-A view defines the buccolingual relationship of
an object.

Parallax method:
By Clark & Richards
Based on binocular principle.
• Useful in distinguishing the buccal or lingual
displacement of the canine.

Procedure:
1. In the periapical film, the X-ray is taken in the area
of interest with the X-ray beam passing perpendicular
to a tangent to the line of arch at this point & at an
appropriate angle to horizontal plane.

2. In the second film, the X-ray tube is shifted mesially or
distally round the arch but held at the same angle to the
horizontal plane.

Result:
• It is based on the SLOB principle.
• If the object has moved on the same side as that of
the X-ray tube, it is lingually placed & if it has
moved on the opposite side it is on the buccal side

Radiographic views at right angles:
1. A true lateral view {e.g. Lateral
cephalograph} gives information
regarding the antero-posterior &
ventral location of an object . However,
it gives no information regarding
bucco-lingual {transverse} plane of an
object.

2. A true occlusal view will provide information in the
transverse & antero-posterior direction of an object .

3. True postero-anterior view defines
the ventral plane & buccolingual
relationship of an object.

These views provide complete information regarding 3
planes of space of any impacted teeth

CT Scanning:
By Ericson & Kurol
• Used to diagnose the exact
position of an impacted
tooth.
• Clear serial radiographs
may be taken at graduated
depth in any part of human
body in this method.www.indiandentalacademy.com

• This technique allows the
elimination of superimposition of
other structures.
• It is however rarely used in the
diagnosis of impacted teeth because
of
( 1) Large radiation dosage.
(2) High cost.

Spiral CT scanning

Prognosis (Ericson & kurol)
 Deep infraosseous location of impacted canine can be assessed
on panoramic image
 CRITERIA
 The midline
 Occlusal plane
 Long axis of incisors,1st
bicuspid and impacted canine
 Angle between long axis of impacted canine and midline
 Distance between the cusp of the impacted canine and the
occlusal plane.

Evaluation
 Most medial position of the crown is identified and severity of
the overlap assessed.
 Canines placed mesial to lateral incisor, distal to premolar =
success rate is less
 Angulation between long axis of canine measured in relation to
the midline.
 Angulation greater than 40° shows poor prognosis.
 Vertical height in millimeters from the canine tip to the occlusal
plane greater than 15mm reveals poor prognosis.(Avg treatment
time ≤ 14 mm = 24M, ≥14mm = 31months)

PREVENTION
 Before the age of 11 years will normalize the
position of ectopically erupting permanent canine
in 91% of the cases, if crown is distal to the
midline of lateral incisor.
 Success rate is only 64% if the crown is mesial to
the midline of lateral incisor.

TREATMENT ALTERNATIVES
1. No treatment, if the patient does not desire it. it should be
periodically evaluated.
2. Auto transplantation of the canine.
3. Extraction of impacted canine and moving premolar in
its position.
4. Extraction of the canine & posterior segmental
osteotomy to move the buccal segment mesially to close the
residual space.

5. Prosthetic replacement of the canine, not amendable
for juvenile cases.
6. Most desirable approach is surgical exposure of the
canine followed by orthodontic treatment .

WHEN TO EXTRACT AN
IMPACTED CANINE
* If it is ankylosed & cannot be transplanted.
* If it is undergoing external or internal root
resorption.
* If the root is severely dilacerated.

 If the occlusion is acceptable, with first premolar in
canine position.
 If there are pathologic changes {cystic formation,
infection}.

PALATAL VERSUS LABIAL IMPACTIONS
• Incidence - Palatal : Labial is 2:1 or 3:1.
• Ectopic labially positioned canines may erupt on their own
without surgical exposure.
• Palatally impacted canine seldom erupt without surgical
intervention due to thick palatal cortical bone & dense &
resistant palatal mucosa.
• Palatally impacted canines are more often inclined in a
horizontal / oblique direction .
• Labial impactions are more often vertically inclined.

Palatal displacement of canine and maxillary
skeletal width ( ajo, apr.06)
By Marayam,Rose,Joe

In a multivariable analysis, there was no statistically
significant difference between subjects with PDC and subjects
with spontaneous canine eruption in (1) J-J,
(2) J-J/AG-GA, (3) AG-GA J-J, (4) NC-NC, and (5)
maxillary intermolar width.
There was a statistically significant difference in Ca-Ca between
PDC subjects and those with spontaneous canine eruption.

Further analysis of data showed that the
absence of maxillary deciduous or permanent canines
in the dental arch (whether due to extraction, exfoliation,
impaction, or not yet having erupted) was associated
with smaller Ca-Ca.
Decreased Ca-Ca is a result of the eruptive status of
deciduous or permanent canines rather than the cause of
impacted canines. These findings suggest that Ca-Ca is
not a good predictor of palatal canine displacement.

Peridontal considerations
 Mcdonald and Yap evaluated the relationship between the
amount of bone removed during surgical procedure and
subsequent bone loss around impacted tooth after
treatment
 Kohavi et al compared the periodontal health of impacted
canine exposed by the radical exposure and exposed by a
more conservative light exposure.

 Exposure of the CEJ is a critical variable and should be
avoided as an objective during surgery.
 Kohavi et al suggested that light movements like tipping
cause less bone loss than heavy movements (torque)
during the traction of impacted tooth.
 Combined effects are beneficial to the future periodontal
health of tooth.

TYPES OF FLAPS FOR IMPACTED CANINE
• Exposure only
• Exposure with pack

Circular incision
 Buccally accessible impacted
teeth
 Made on the sulcus mucosa
immediately over the crown,to
expose the the bony crypt,
which lodging the impacted
tooth.
 Advantages:
 Easy to perform
 Suitable access can be provided
for bonding of the attachment

Disadvantages:
 a) elongated clinical crown
 b) buccal positional relapse
 c) On the labial side tooth will be invested with thin oral
mucosa rather than attached gingiva.

Apically repositioned flap
 This method was proposed by
Vanarsdall and corn in 1977.
 In absence of the deciduous
canine , flap is raised from the
crest of the ridge that includes
attached gingiva.
 In presence of deciduous canine,
flap is designed to include the
entire buccal gingiva that invests
it.

 In either case, flap is detached from the underlying hard tissue
Some way up to sulcus, to expose the crown.
 Flap is then sutured to the labial side of the permanent canine to cover
the denuded periosteum and overlying cervical portion of crown,
while the remainder of crown remains exposed.
 Advantages:
 Maintains the width of attached gingiva.
 Easy access for bonding of the attachment
 Tooth can be visualized from the time of exposure still it come to
occlusion.

 Disadvantages:
 Vermette in 1995 ,found several drawback in relation to aesthetic and
Peridontal results of apically repositioned flap
 1) Uneven and unesthetic gingival margin
 2) Increased Clinical crown length
 3) Some degree of attachment loss and bone loss on the labial
surface, which was considered as possibly related to an increased
potential for plaque accumulation
 4)Vertical orthodontic relapse: - After apical repositioning , the
gingival tissue heals to the adjacent mucosa, producing soft tissue
band of gingival scarring. As the tooth is pulled incisally this mucosa
get stretched down with it, toward the alveolar crest. Thus it tend to
relapse once the force is released.

Full flap closure
 This method was proposed by
MCBride in 1979.This method is
more effective for buccal and
palatally impacted tooth
 Procedure:
 A full buccal surgical flap is
raised as high as necessary to
expose the canine. An attachment
with a twisted thread is bonded to
the tooth and the flap is sutured
back to its former place itself..

 Then a Twisted thread drawn inferiorly through the sutured edges of
the replaced flap at the crest of the ridge or through the socket
vacated the extracted deciduous canine.
 Advantages:
 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) Immediate traction possible
 e) Less discomfort and good post operative Haemostasis
 Disadvantages:
 Placement of the bonding attachment is necessary at the
time of exposure.
 If there is a bond failure it needs re-exposure.
 Difficulty in gaining dry field.

GENERAL PRINCIPLES OF
MECHANO-THERAPY
 The appliance should have the capability to level and rotate
all the teeth in same jaw rapidly, and with controlled crown
and root movents.
 To open adequate space to accommodate the impacted tooth.
This stage requires the use of fine leveling and aligning arch
wires.
 With the initial alignment achieved and no further movement
of individual erupted teeth needed, these teeth are
transformed into a composite and rigid anchorage unit, this is
done by substituting the flexible arch wires with a heavier
wire.

 The surgical exposure of the crown of the impacted tooth
should be performed in a manner that will achieve a good
periodontal prognosis of the treated result. An attachment is
bonded to it and the flap fully closed, with only a fine
ligature wire leading through the gingival tissue to the re-
covered tooth.
 Using an auxiliary means of traction from the now rigid
orthodontic appliance, a gentle and continuous light force,
with a wide range of activity, is applied to the tooth, and is
aimed at erupting the impacted tooth.
 5.There should be final detailing of the position of the
formerly impacted tooth.

Attachments: –
 Lasso wires
 Threaded pins
 Orthodontic bands
 Standard orthodontic bracket
 A simple eyelet
 Elastic ties and modules
 Magnets

{a} Lasso wires:
It is twisted lightly around the neck of the canine.
Disadvantages:
 This results in irritation of the gingiva
 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.www.indiandentalacademy.com

(b) Threaded Pins:
Provide 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).
So it is rarely used. www.indiandentalacademy.com

{c} Orthodontic bands:
They largely replace the
Lasso wires & threaded pins.
Advantage:
They are compatible with the health of periodontal
tissues.
Disadvantage:
- Large surgical field required.
- Inadequate moisture control may hamper with the
cement-band bond.

{d}Standard orthodontic brackets:
Any edge-wise , Begg’s , PAE brackets can be
used.
They are routinely used as direct attachments along
with the composites.(MIP Adhesive)

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.

{e} A simple eyelet:
- An eyelet welded to band material with a mesh backing is
soft & easy to contour, making its adaptation to bonding
surface more accurate.
Advantages:
- Because of small size they can be placed in more
awkwardly placed teeth.
- It is less irritating to the surrounding tissues.www.indiandentalacademy.com

(f) 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

{f} Magnets:
It is made up of rare earth lanthanide alloys .
• It is rarely used.
Disadvantage:
- corrosion.

MECHANOTHERAPY
Various methods have been used for moving the canine in to
proper alignment with following considerations:
• The use of light force (not more than 60 - 150 gms).
• Creation of sufficient space.
• Maintenance of the space.
• Arch wire of sufficient stiffness.

BALLISTA SPRING
• Harry Jacobay (1979)
A J O 1979www.indiandentalacademy.com

Ballista Spring
•It is tied into the head gear tubes of 1st molar.
•It proceeds forwards until it is opposite the canine space, at this
point , is bent vertically downwards terminating in a small loop.with
light finger pressure, the vertical portion is turned upwards, across
canine space and tied into the pigtail ligature.
In this way torque is introduced into the horizontal part of the
ballista, which is resisted great extent by the molar.

2) Active palatal arch (Becker1978)
It consist of fine 0.020 inch removable palatal arch wire
carrying an omega loop on each side. End of the wire is doubled
for Friction fit in lingual sheath.It is activated by elevating
downward and hooking the pigtail ligature around it

3) Light Auxiliary Labial Arch (Kornhauser1996)
It is made up of 0.014 inch round SS wire with vertical
loops in the area of impacted canine on both sides.This loop has a
small helix.This wire is tied with the basal arch wire in piggyback
fashion.If basal arch wire is not used it will leads to extrusion of
adjacent tooth and cause alteration of occlusal plane .

CANTILEVER SPRING
• Lindauer and Isaacson (1995)
• TMA .017 X .025 wire used
• Force generated was measured
by dontrix guage.
• It should not exceed 70gms.
JCO Feb 1999www.indiandentalacademy.com

TMA BOX LOOP
• TMA .017 X .025 wire
used.
• Produce sagittal and
horizontal corrections while
continuing vertical eruption.
Surendra Patel J C O 1999

NICKEL TITANIUM CLOSED-COIL SPRING
Loring L.Ross (1999)
• 0.009”X 0.041” spring
• Provides 80 gm of force when stretched to twice
its resting length

Procedure

TWO ARCH WIRE TECNIQUE
• Samuels.R.H.A (1997)
• Gold chain is preferable because of
flexibility and biocompatibility.
JCO March 1997www.indiandentalacademy.com

An .014" nickel titanium archwire is used for attachment
to the gold chain, and a main archwire is placed in the
same bracket slots, over the traction archwire, for
anchorage and control of the archform.
The nickel titanium wire should be cut so that it passes
through two or three brackets on either side of the
impacted tooth. It is held in place with two or three
elastomeric ligatures.

The traction archwire should be deflected 3-4mm toward the
gold chain at the traction site and tied to the chain with a
soft stainless steel ligature.
 Traction to the gold chain is reactivated every four to six
weeks by removing links of chain and retying the chain to
the traction archwire

THE MONKEY HOOK
S.Jay Bowman (2002)
• 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. JCO July 2002www.indiandentalacademy.com

A combination of monkey hooks and bondable loop-
buttons allows the production of a variety of different
direction force such as:
I. Vertical intermaxillay eruptive forces
JCO July 2002www.indiandentalacademy.com

II. Vertical intra arch eruptive forces
JCO July 2002www.indiandentalacademy.com

III. Lateral directional forces
JCO July 2002

THE K- 9 SPRING
•Varun Kalra (2000)
• Made in 0.017”X 0.025”TMA wire
Adv:
• Simple in design
• Low cost
• No patient compliance
• Light continuous eruptive and distalizing
forces
JCO Oct 2000www.indiandentalacademy.com

Fabrication and Activation
JCO Oct 2000 www.indiandentalacademy.com

JCO Oct 2000 www.indiandentalacademy.com

JCO Oct 2000

AUSTRALIAN HELICAL ARCHWIRE
• Christine Hauser (2000)
• Made in special plus .016”
arch wire
• Force should not exceed
200 gm
• Activation by twisting the
steel ligature wire every
two weeks
JCO Sep 2000www.indiandentalacademy.com

The amount of force can varied by using different
arch wire designs
JCO Sep 2000

MAGNETS
JCO 1994
 J.P.sandler
 Involves the use of two magnets
 1) 3×3 ×1mm NdFeB
 2) 5×5×2mm

Procedure
JCO 1994

Tunnel traction of infraosseous
impacted canines
A.crescini et al(1994)
Adv:
• No attachment loss
• No recession
AJO 1994

 Full thickness flap raised ( Impacted tooth exposed)
↓
 Deciduous canine extracted
↓
 Socket is extended and widened sufficiently to allow passage of fine
wire through it
↓
 An eyelet attachment on steel mesh is threaded with 0.011’’ligature
wire bonded on impacted canine
↓
 Surgical flap resutured to its former position
↓
 Formed tunnel is used for traction
↓
 Traction phase started after one week and directed to the center of the
alveolar ridge.

RETENTION CONSIDERATIONS
Evaluation of post treatment alignment by Becker et al
• Incidence of rotations and spacings
1. Impacted side- 17.4%
2. Control side 8.7%

To minimize rotational relapse, options available are
1. Fiberotomy
2. Bonded fixed retainer
This can be done during or after the treatment.
Clark’s suggestion for palatally impacted canine: Lingual
drifting can be prevented by removal of halfmoon- shaped
wedge of tissue from lingual aspect of canine.

complications

CONCLUSION
Orthodontic management of impacted canines can be
very complex and requires a carefully planned inter-
disciplinary approach.
As canine has unique functional and aesthetic
importance,clinicians usually elect to bring an
impacted canine into proper position to give a better
smile. www.indiandentalacademy.com

Management of impacted canine

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Management of impacted canine