Impacted canine
Upper canine are more frequently fail to
erupt than lower canine . In both cases
malposition of the unerupted tooth is
common and in some circumstances the
tooth lies out of its normal path of
eruption .Failure of bilateral upper canines
to erupt properly is also a frequent
occurrence.
• Normally, the maxillary canine teeth are the
last of the “anterior” teeth to erupt into place.
They usually come into place around age 13
and cause any space left between the upper
anterior teeth to close tight together
Classification of impacted maxillary
canine
•
•
•
•
Class 1 palataly impacted
Class 2 labially impacted
Class 3 intermediate
Class 4 impacted canine in edentulous patient
The exact position of the tooth and the precise
relationship to other unerupted teeth must be
determined
.
it is of particular importance to determine
whether impacted tooth lying labially or palataly
to the standing teeth , so that the surgeon knows
whether to use a labial or palatal approach. If the
impacted tooth lies within the arch of the standing
teeth the use of both labial and palatal approach
may be indicated .
1- disturbance of the long axis of the tooth
germ .
2-scar tissue in the path of eruption .
3-Failure of the root of the deciduous
predecessor to resorbed.
4- ankylosis of the deciduous predecessor
5- congenital absence of the lateral incisors , the
root of which may act as a guiding influence for
the canines.
Mosul university- College of dentistry-oral & maxillofacial surgery department
-maxillary canines start their development at
a higher level than the adjacent teeth .with a
greater distance to travel through the bone
to its normal position there is an increased
chance of deflection from its path .
In a crowded arch , the additional space
required for the canine may be taken up by
the first premolar which erupted before the
canine .
Mosul university- College of dentistry-oral & maxillofacial surgery department
If by the age of 13 the upper canine have failed to
erupt their position should be investigated .
1- inspection
A- the canine may be partially erupted
B- there may be an obvious bulge on either the
buccal aspect of the alveolar process or in the
palate ,which denote its position . A palatal
impaction is more common than the buccal.
Mosul university- College of dentistry-oral & maxillofacial surgery department
C - Occasionally the lateral incisor may be
proclined due to the presence of the canine
crown lying labial to the root . Palatal inclination
of the lateral incisor can be caused by a palataly
placed canine which is impacted against the
apical part of its root
2 - Palpation of the maxilla through the
labiobuccal sulcus may also reveal the crown of
the tooth to be high in the maxilla and adjacent
to the floor of the nose .
.
Mosul university- College of dentistry-oral & maxillofacial surgery department
The periapical radiograph provide a
detailed picture of the tooth and its
surroundings
and
is
helpful
for
demonstrating the degree of root formation
of the canine , apical curvature , the
existence of any root resorption affecting
the adjacent lateral incisor and the presence
of an associated cyst .
Mosul university- College of dentistry-oral & maxillofacial surgery department
The relative radiopacity of the crown
of the impacted canine may assist in
the determination of the tooth
position (the more radiopaque lie
palataly )
The occlusal views are 3 types ,anterior ,
vertex , and true . the vertex occlusal
technique is the only technique used for
determination of the true position of the
impacted tooth.
the anterior occlusal radiograph is taken
the x ray tube is sited at the nasion
the vertex occlusal view the x ray tube is
arranged so that the central ray passes
along the long axis of the central incisors
the true occlusal view is taken with x
ray tube positioned so that the central
ray is at right angle to the film
Parallax method in this technique a
periapical radiograph of the area is taken and
the x ray tube is then moved in either mesial
or distal direction before a second periapical
film is taken .the two radiograph is then
compared and if the impacted tooth seen to
move in the same direction as the x ray tube
it is lying palataly , whilst if it moves in the
opposite direction it is lying labially.
Treatment options of impacted upper
canine
1- no treatment •
2-surgical exposure •
3- surgical exposure with orthodontic traction •
4- Surgical removal •
5-Reimplantation •
1- before the insertion of complete or partial denture or
a bridge .
2- to permit orthodontic alignment of other anterior
teeth.
3- where there is resorption of the root of an adjacent
lateral or central incisor .if resorption is noticed at early
time , it may be arrested by removal of the impacted
canine , but , if resorption is marked ,exposure of the
canine and removal f the lateral incisor should be
considered .
4 – where a follicular cyst has developed
If the canine located buccally a buccal incision
should be made and if it is impacted in the
palate a palatal approach is required .. If the
long axis of the impacted canine lies across the
arch with the root lies on one side and the
crown on the other both labial and palatal flaps
should be reflected from the beginning.
In the edentulous patient one incision made
along the crest of the ridge will permit access
from both aspects .
Incision in the palate should never be made
directly over the impacted tooth . If the suture
edges of the flap rest over a socket this will
lead to the formation of an oroantral or
oronasal communication .
Three sided flap is designed so that
complete interdental papilla is left at each
corner .after the flap has been raised a bony
bulge may be visible or palpable indicating
the site of the impacted tooth .
Mosul university- College of dentistry-oral & maxillofacial surgery department
Sufficient overlying bone is removed to
expose the crown of the impacted tooth
.if root configuration prevent simple
elevation the root should be exposed
over a good part of its length before
further force is applied .if delivery of the
canine still can not be effected , the
tooth must be divided at its neck and the
2 segments removed separately .
The incision for creation of the flap begins at
the first or second ipsilateral premolar and,
after continuing along the cervical lines of
the teeth, ends at the first premolar on the
contralateral side
The mucoperiosteal flap is raised with a
Howarth periosteal elevator ,working from
each side toward the midline .the
neurovascular bundle passing through the
incisive foramen should be divided with a
sharp scalpel close to the bone .
Mosul university- College of dentistry-oral & maxillofacial surgery department
Once the palatal mucoperiosteal flap has been
raised , the crown of the tooth may be
immediately visible , or a bulge may present in
the palate and there is a thin layer of bone
overlying the crown . The bone should be
removed to expose the neck of the impacted
tooth .
Mosul university- College of dentistry-oral & maxillofacial surgery department
When the root of the canine lies across the
alveolar process between the root of the
standing teeth , in this case both palatal and
buccal flaps are raised (contagious flap).
A thin acrylic palatal splint held in place by a
clasp on the first molars , will prevent the
formation of a hematoma beneath the palatal
flap .
Mosul university- College of dentistry-oral & maxillofacial surgery department
1- hematoma can some times developed.
Patients will return with the hard palate
bulging down from the roof of the mouth
as a result of a large hematoma collection
.this complication can be prevented by
acrylic splint fabricated before surgery .
Mosul university- College of dentistry-oral & maxillofacial surgery department
2-perforation into the floor of the nose may
occur with some post operative nasal
bleeding . If a small opening is seen during
surgery it should be covered with a small
layer of gel-foam or surgicel or collagen
membrane before the mucosal closure .
Mosul university- College of dentistry-oral & maxillofacial surgery department
Alternative methods of treatment of
the unerupted canine
1 – leave it in situ( no treatment)
2 - Surgical exposure( when the path of
eruption is unobstructed )
3-surgical exposure with orthodontic traction
(when the path of eruption is obstructed )
4- transplantation and surgical repositioning .
Leave it in situ
It is indicated when
1- the impacted canine is asymptomatic.
2- its extraction might cause damage to the adjacent
teeth .
3- When there is intimate contact between the lateral
incisor and the first premolar where it is acceptable
from the esthetic point of view.
The patient should be kept under annual review to
see if any complication occur .such as resorption of
adjacent tooth or progressive widening of the
follicular space .
Surgical exposure
An attempt is made to assist the eruption of a
malposed and unerupted canine into a normal
functional position . It is considered when :
1- there is adequate distance in the arch to
accommodate the tooth .
2- when the potential path of eruption is
unobstructed
3- exposure of the crown can be carried out as
close as possible to the time at which normal
eruption would occur .
Surgical exposure :the path of eruption is not
obstructed
Surgical exposure with orthodontic
traction: the path of eruption is obstructed
Surgical exposure with orthodontic
treatment (palatal approach )
The initial stage of the operation is to reflect
the mucoperiosteum and to remove the bone
overlying the tooth to expose the greatest
coronal diameter, the incisal edge and the
cingulum .
before repositioning the palatal flap a window
is excised in it corresponding to the bony
cavity containing the crown .the flap is then
sutured as usual and a pack of iodoform gauze
should be pressed firmly in to the bony defect
so as to cover the exposed crown .
This pack should be held in position with suture
and left insitu for 2-3 weeks to prevent
granulation tissue and mucosa from overgrowing
the denuded crown .after removal of the pack
the progress of eruption should be observed at
frequent intervals .
Following exposure of the tooth , orthodontic
treatment may be required to guide it into a
good position in the arch . Some times
orthodontic traction is arranged at the time of
surgery .
Mosul university- College of dentistry-oral & maxillofacial surgery department
Transplantation and surgical
repositioning
The success rate with transplantation is highest
for
1- unerupted teeth which have open apices
because of the possibility of revascularization .
2- It is essential to establish that there is
sufficient space to accommodate the canine
crown. minimal space deficiency may be
overcome by grinding of the crown , but
otherwise orthodontic therapy may be
required to move the premolar distally .
3-The canine should be extracted carefully
and
transferred to the surgically prepared socket
in the dental arch with the minimum of delay.
It is preferable that the root surface should
not be touched either with instruments or
fingers as the viability of the cementum and
periodontal membrane remnants will
determine the success of the transplant. The
tooth is stored under the flap to keep the
tooth moist until the new socket is prepared .
Root filling is not attempted so as to reduce
handling of the tooth .
4- The transplanted tooth should be splinted
in its new position for a month after the
operation .
Surgical repositioning
• In the technique of surgical repositioning , the
displaced tooth is not extracted but rotated or
tilted about its apex . It is indicated when the
tooth is fully erupted , but the crown is out of
the line of the arch .
• There must be adequate space for the canine
in its correct position
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