Impacted upper canines / for orthodontists by Almuzian

Mohammed Almuzian, University of Glasgow, 2014 Page 1
UNIVERSITY OF GLASGOW
Impacted maxillary Canines
Personal note
Mohammed Almuzian
1/1/2014
.

Impacted maxillary Canines
Introduction
1. Unerupted and Impacted of canines is a frequently encountered clinical problem. If orthodontic
treatment is not started, there is always a risk of retention and also of resorption of the roots of
the permanent incisors.
2. Impaction is from a Latin word impacto which means pressing together (Thomas 1984).In dental
term, impaction means failure of tooth eruption to occlusion due to physical obstruction e.g.
supernumerary prevents maxillary incisors from eruption. However, in most cases of canines
impaction, no obvious physical barrier to eruption is found.
3. Some authors prefer the term unerupted or nonerupted canines to describe the condition (Rayne
1969, Von der Heydt 1975, Krejci and Bissada 1988, Mermingos and Full 1989). In the
assignment, the term unerupted canine or unerupted maxillary canines (UMC) , palatal
displacement canine (PDC) and impacted maxillary canine (IMC) will be used.
4. Uneruption of canines is a common clinical problem. The maxillary canine tooth is second only
to the mandibular third molar in its frequency of impaction . The report ed prevalence varies
from less than 0.8-2.8 per cent ( Shah et al., 1978 ; Grover and Lorton , 1985 ). and the incidence
of mandibular canine uneruption is only 0.35% (Dachi and Howell 1961). Since failure of
maxillary canines eruption occurs more frequently, the emphasis of this assignment will be on its
incidence, normal develop and eruption, aetiology, complication, assessment, prevention and
treatment.
5. Normal development and eruption pattern: Broadbent (1941) stated that calcification of the
permanent maxillary canine crown starts at 1 year old, between the roots of the first primary
molar , and is complete at 5-6 years. By the age of 12 months the crown of the tooth is found
between the roots of the first primary molar. At 3-4 years of age the canine passes over the line
of the primary incisors to lie on the labial side of the root of the lateral incisor( Miller,1963). At
age 4 years the primary first molar, the first premolar germ and the canine lie in vertical row .
Subsequent growth on the facial surface of the maxilla provides space for the forward movement
of the canine so that its cusp comes to lie medial to the root of the deciduous canine. Moss
(1972) states that the canine remains high in the maxilla just above the root of the lateral incisor
until the crown is calcified.It then erupts along the distal aspect of the lateral incisor resulting in

closure of the physiological diastema if present and the correction of the so called ‘Ugly
Duckling ‘dentition ( Kurol et al.,1997 )
6. Has long path of eruption from the infra-orbital place along the roots of 2 causing ugly duckling
space which resolve later, and then pass along the buccal surface of the c.
7. Upper erupts 11-12yrs
8. 3's palpable in buccal sulcus by 8-10 yrs old (Ferguson, 1990)
Prevalence
1. Developmentally absent 3's: 0.08% (Brin et al, 1986)
2. Impacted 3's: 2% (Ericsson, 1986)
 Review of the dental literature reveals that the incidence of unerupted or impacted canines to
range from1.5 to 3.0 % of the general population.
 Frequency: The maxillay canine is second only to the mandibular third molar in its frequency of
impaction.The frequency varies from less than 0.8-2.8 % ( Shah et al.,1978; Grover and Lorton .
1985 )and the incidence of mandibular canine uneruption is only 0.35% (Dachi and Howell
1961).
 Sex: The condition is more than twice as common in girls(1.2 %) than in boys ( 0.5 % ) ; Dachi
and Howell, 1961 ; Ericson and Kurol 1986; Rayne 1969 and Peck et al 1994)
 Family history
 Site: Canine impaction is found palatal to a the arch in 85 % of cases and labial/buccal in
15%(Rayne,1969;Ericson and Kurol, 1987 ). Johnston and Gaulis and Joho also stated that
impacted maxillary canines are more often situated in a palatal than in a labial position, in a ratio
of approximately 2 to 1 . Ericson and Kurol (1986) reported that 8% of PDC were bilateral.
However, a much higher incidence has been reported by Bass (1967) Rayne (1969) which was
17% and 25% respectively.Becker et al.5 found 70% incidence in females with 45% of the
sample showing bilateral impactions. Kuftinic found that laterality existed in the incidence of
canine impactions. Left side impactions occurred more frequently than right sided ones in the
ratio of 5:2. The palatal displaced canine usually is detected late i.e. after the age of 13 and 14
and it requires surgical treatment. Palatally displaced canines very rarely erupt spontaneously.
However, the buccally unerupted canines, in most cases, are detected and operated much. It is
impossible to verify that those labially unerupted teeth could not erupt spontaneously in a labial

ectopic position. There is some evidence that patients with class II division 2 malocclusions and
tooth aplasia may be at higher risk to the development of an ectopic canine. ( Kettle,1957; Harzer
et al .,1994; Mossey et al.,1994;Brenchley and oliver,1997).
Complication
1. Nothing
2. May erupt in a Labial / lingual malposition
3. If the C lost, then Migration of neighbouring teeth and loss of arch length
4. Internal or external root resorption of teeth adjacent to impacted canine.
5. Resorption of canine itself can also occur.
6. Dentigerous cyst formation and infection with referred pain
7. Damage to adjacent teeth during surgery
8. Ankylosis
Aetiology
The aetiology of the ectopic canine is obscure, but probably multifactorial .The maxillary
canine has the longest path of eruption in the permanent dentition and this may be a factor in the
aetiology ( Coulter and Richardson , 1997 ). Moyers (1963) summarised the aetiology of UMC
into primary causes and secondary causes :
1. Primary causes :
a) rate of root resorption of deciduous teeth
b) trauma to the primary tooth bud.
c) disturbances in tooth eruption sequence.
d) availability of space in the arch.
e) rotation of tooth buds.
f) premature root closure.
g) canine eruption into the cleft area in the persons with cleft palate.

2. Secondary causes :
a) abnormal muscle pressure.
b) febrile diseases.
c) endocrine disturbances.
d) vitamin D deficiency.
The most common causes for canine uneruption are usually localised and are the results of any
one, or combination of the following factors (Bishara 1992):
A: Tooth size-arch length discrepancies: Crowding is the most common cause of tooth
impaction. However, lack of space is usually associated with labially unerupted maxillary
canines but not PDC. (Jocoby 1983).
B : Prolong retention or early loss of the primary canine: The prolong retention of deciduous
canine may be related to abnormal slow root resorption rate of primary canines or the result of
ectopic eruption of permanent canine. However, removal of primary canines in PDC cases
improves the severity of impaction (Ericson and Kurol 1988a). The early loss of the primary
canine may be an indication of arch length discrepancies.
C : Abnormal position of tooth bud: Many authors support that a more difficult and tortuous path
of eruption and true ectopic development is one of the main causes of unerupted canines (Rayne
1969, Von der Heydt 1975, Chase 1989, Peck et al 1994). Becker (1995) argued that if there was
a clear and unequivocal ectopic development of the entire tooth bud from the earliest stages, a
positional anomaly of major proportions should be indicated. However, PDC usually referred to
a crown displacement only, with the root more or less ideally placed.
D : Presence of an alveolar cleft: Local disturbance may deflect eruption of canine or just lack of
alveolar bone may delay or prevent eruption (Rayne 1969). Other dental anomalies e.g..
supernumerary, presence of scarred tissue, may affect the eruption of maxillary canines.
E : Ankylosis: Ankylosis of maxillary canine is uncommon but still is a possible cause of
uneruption. Anecdotal clinical experience of canine traction after surgical exposure indicates a

low incidence of ankylosis (Counsel 1997, personal communication). New surgical technique
which minimises the damage the root surfaces prevents iatrogenic ankylosis.
F : Cystic or neoplastic formation: Physical obstruction by cyst or neoplasm in the path of
eruption may cause deflection of the crown of the canine (Ferguson 1990). However, the
incidence of cyst and neoplasm is much lower than incidence of UMC. Moreover, the cystic
appearance related to PDC in the radiograph might be enlarged follicle due to delayed eruption
instead of the cause of impaction.
G : Dilaceration of root: Rayne (1969) concluded that the mechanism of impaction was one of
maldirection of eruption; the inclination of the impacting canine was mesial, and it became
deflected by the root of the lateral incisor. Dilaceration of the apex might result from proximity
to the wall of the nose or the floor of the antrum.
H : Iatrogenic origin: Broadbent (1941) suggested the early correction of the flared and distally
tipped lateral incisors might either impact the canines or cause resorption of roots of the lateral
incisors. This view has been shared by many other clinicians. (Duncan 1997, Darendeliler 1997,
Vickers 1997, personal communication).
I : Idiopathic condition with no apparent cause: This covers everything under the sun!!
Jocoby (1983) found that 85% of the PDC had sufficient space for eruption. He concluded that a
canine could be palatally impacted if an extra space was available in the maxillary bone. This
space should be provided by:
a) excessive growth in the base of maxillary bone;
b) space created by agenesis;
c) stimulated erupted of lateral incisor or the first premolar.
Other factors are also suggested as aetiology of UMC (Ferguson 1990):
a) Narrowness of the upper arch
b) Class II division 2 incisor relationship
c) Familial tendency

Theories
The recent debate of the aetiology of PDC between Lateral Incisors Guidance Theory
(Becker et al 1981) and Genetics Factors as Primary Origin (Peck et al 1994) generate a lot of
interest in this area (Becker 1995, Peck et al 1995). Jacobs (1996) reviewed both theories in his
review article.
 Guidance theory, evidences: Small, peg-shaped or missing maxillary lateral incisors have been
implicated in contributing to the palatal impaction of maxillary canines. Jacoby (1983) found that
the presence of excessive arch space due to agenesis or peg-shape lateral incisor was one of the
aetiology of PDC. Brin et al (1986) found that if a patient had a small or peg lateral incisor, there
was approximately a 1:10 probability that the canine would be palatally placed; and if the patient
had a missing lateral incisor, a 1:20 probability. Becker et al (1984)found absence of maxillary
lateral incisors in 5.5 % of a large group of patients with palatal canines, which is 2.4 times the
rate in the general population and concluded that anomalous or missing lateral incisors
contributed towards palatal displacement of canines initially by absence of guidance for erupting
canine, and later by obstructing the misplaced canine’s attempt to rectify its position (Jacobs
1996)
 Genetic theory, polygenic inheritance, evidences: Peck. A genetic or familial trend has been
pointed out by some workers (Peck et al., 1994). Pirinen et al. (1996) examined first and second
degree relatives of 106 consecutive patients with displaced canines, and concluded that palatal
displacement of the canine is both genetic and related to hereditary incisor or premolar
abnormalities such as peg-shaped lateral incisors. Mossey et al. (1994) found a weak statistical
relationship between the occurrence of a palatally displaced canine and the absence or reduced
crown width of the adjacent lateral incisor , but Brenchyley and Oliver (1997) were unable to
comfirm this finding in respect of crown size. Peck et al (1994) reviewed the literature and stated
that the evidence pointed to genetic factors as the primary origin of most PDC. They grouped
their material into five categories.
1) Occurrence of other dental anomalies: Other dental anomalies besides size reduction or absence
of maxillary lateral incisors e.g. canine transposition with first premolar are associated with

PDC. A genetic interrelationship exists among tooth agenesis, systematic tooth size reduction
and generalised retardation of tooth development.
2) Bilateral occurrence: High percentage of bilateral occurrence of PDC indicated an intrinsic
aetiology such as a genetic mechanism.
3) Sex difference: Sex ratio reporting patterns of male-female differences suggested genetic links
involving the sex chromosomes. Male to female prevalence rate ratios range from 1:1.3 to 1:3.2
which compare favourably with sex ratios recorded for other dental anomalies of genetic origin.
4) Familial occurrence: There was an elevated occurrence rates of PDC and various related
anomalies among other family member.
5) Population differences: The difference frequency of PDC in different populations, coincident
with racial grouping, is supportive evidence of genetic involvement in the aetiology of PDC.
Peck et al (1994) concluded that mechanical causes such as blockage form retained
primary canines or from dental arch space inadequacies were not valid. They also suggested that
PDC was not a dependent variable of anatomical variations of the maxillary lateral incisor but
that the associated canine and lateral incisor phenomena are covariables: coincident traits
appearing within the context of genetic control. The clinical significance of genetic theory is that
siblings are at a higher risk of having PDC than other members of the population
Diagnosis unerupted teeth
1. Inspection
Clinical signs of impacted 3s
 Delayed eruption
 Asymmetrical eruption
 Prolonged retained c
 Absence of buccal budges at age of 10 years
 Presence of palatal budges
 Angulated laterals
 Change colour of 1 or 2

2. Palpation and percussion
a) Palpation of the upper canines is a vital step in assessing the developing dentition.
b) Deciduous canines or adjacent permanent teeth should be checked for mobility, tenderness and
vitality
3. Diagnostic imaging and unerupted teeth
Features of ectopic maxillary canines that should be determined by radiographs
1. Presence or absence of the canine
2. Overall stage of dental development
3. Local anatomic considerations
4. Size of the follicle
5. Inclination of the long axis of the tooth
6. Relative buccal and palatal positions
7. Relative superior-inferior positions
8. Amount of the bone covering the tooth
9. 3D proximity and resorption of roots of adjacent teeth
10. Condition of adjacent teeth
Radiographical techniques
I. Right angle technique
a. The use of two radiographs taken at right angles to one another allows three dimensional
localisation of the canine; e.g.
• Lateral and posterio-anterior cephalometric films
• Occlusal vertex film with OPT
• Mand occ and opt or ceph for lower canines
b. But this technique need additional film for fine details.
Disadvantages associated with the vertex occlusal radiograph:
1. A large radiation exposure since the brain, the pituitary, salivary glands, thyroid, and the lenses
of both eyes receive unnecessary exposure.
2. The film is usually difficult to interpret.

Because of these disadvantages the British Orthodontic Society guidelines for radiography state
that there are very few indications for a vertex occlusal view in any patient even when taken with
rare earth intensifying screens/cassette.
II. Magnification technique
V.Gavel and L. Dermaut (1999) evaluated localization of impacted canine by using panoramic
tomograms to define the exact location and concluded that :
 Although buccal impaction shortens the tooth length on the films ,this is mostly caused by its
inclination in a sagittal direction. The more thetooth is uprighted in the frontal plane, the more
pronounced the influence of the sagittal inclination on tooth length.
 Displacing the impacted tooth in a posterior direction (i.e. palatal impaction) widens the crown
width. Inclination in a sagittal direction and uprighting towards the mid-sagittal plane enchances
this phenomenon.
 The impacted position(Buccal/Palatal) of the impacted canine does not influence angulation
tooth-axis/ occlusal plane.This value changes negatively when the tooth is inclined in a sagittal
direction and positively when the tooth is uprighted in the frontal plane.
 Buccal and median impaction ( in the frontal plane ) shorten the imaged distance to the mid-
sagittal plane compared with imaging of the well-aligned canine.Displacement in a sagittal
direction (palatal impaction) widens this distance.
 The migration of the impacted canine in a sagittal or median direction projects the crown point
higher on the panoramic film than a canine bucally impacted at the same vertical level.
 An increased curvature of the root of an impacted canine demonstrates an inclination of the tooth
in a sagittal direction.
 Chaushu and Becker (1999) have described a method of localising maxillary canines using only
a panoramic radiograph. Sensitivity of this technique is 80%
III. Parallax technique (image/tube shift method, Clark’s rule, buccal object rule).
1. It is first described by Clark in 1909

2. Principle of parallax. In radiologic terms, parallax is the apparent displacement of an image
relative to the reference object caused by an actual change in the angulation of the x-ray beam.
 First they used 2 PA radiographs (Clark)
 Then 2 occ radiographs
 Then OPT+occ at 60 degree
 Then OPT+occ at 70degree (Jacobes 1999 in order to increase the effect of parallax)
 The horizontal shift in the horizontal parallex is 10-20 degree
3. DPT overestimates the angulation and underestimates proximity to midline (Ferguson, 1990)
4. Armstrong 2003 fond horizontal better than vertical parallex.
IV. CT spiral scanning
V. Cone beam volumetric tomography (CBCT), CBCT indicate if there is a possible resorption
which cannot be seen by conventional radiograph, Birnie recommend that CBCT would be
indicated in 30% of cases.
Classification of radiographical feature of impacted canine, Power & Short 1993
1. Angulation
 Grade 1=0-15 degree,
 Grade2=16-30,
 Grade 3= more than 30
2. Vertical height
 Grade 1=below CEJ,
 Grade=above CEJ but less than half of root,
 Grade 3= more than half but less than full root,
 Grade4=above apex
3. AP position of root apex
 Zone 1=at area of 3,
 zone 2=above 4,
 Zone3=above5
4. Coronal overlap

 Sector 1=before lateral,
 Sector 2= before long axis of 2,
 Sector 3 after long axis but before central,
 Sector 4=over the central). The same had been used by Kurol and Ericsson 1987.
5. Labio-palatal position of crown and root
6. Resorption
Radiographic Factors Affecting the Management of Impacted Upper Permanent Canines,l
Stivaros & Mandall, 2000
 The aim of the investigation was to evaluate which radiographic factors influenced the
orthodontists' decision whether to expose or remove an impacted upper permanent canine and
was a retrospective, cross-sectional design. The sample consisted of all radiographic records of
patients referred to the Orthodontic Department at Manchester University Dental Hospital with
impacted upper permanent canines between 1994–1998 (n = 44). The following canine position
measurements were made from the OPG: angulation to the midline, vertical height, antero-
posterior position of the root, overlap of the adjacent incisor, and presence of root resorption of
adjacent incisor(s). The labio-palatal position of the impacted canine was assessed from the
lateral skull radiograph. Whether the impacted canine had been exposed and orthodontically
aligned or removed was also recorded.
 Stepwise logistic regression analysis showed that the labio-palatal position of the crown
influenced the treatment decision, with palatally positioned impacted canines more likely to be
surgically exposed and those in the line of the arch, or labially situated, removed (P < 0•05).
Additionally, as the canine angulation to the midline increased, the canine was more likely to be
removed (P < 0•05).
 The orthodontists' decision to expose or remove an impacted upper permanent canine, based on
radiographic information, seems to be primarily guided by two factors: labio-palatal crown
position and angulation to the midline.
Root resorption from ectopic canines
1. Resorption occurred as early as 9 years of age and reached a peak frequency around 10-11 years
(at the normal age of tooth eruption).

2. Incidence: 12% of cases with impacted 3's, amount underestimated with plane R/G, CT studies
show 48% of 2's demonstrate a degree of root resorption (Ericson and Kurol, 2000). Walker
2004 used CBCT and showed 67%
3. Aetiology of resorption:
• Active pressure during eruption.
• cellular activities in the tissues at the contact points.
4. Risk factors for resorption: Ericson & Kurol,1988
• Female
• Age <14yrs
• Horizontal palatal canines
• Advanced canine root development
• Canine crown medial to midline of lateral incisor
• Root of laterals in contact with crown of the canines
5. The following are not significant risk factors:
• Size of follicle,
• Quantity of deciduous canine root resorption
6. Classification of resorption asscoated with U3s (Ericson & Kurol,2000)
 Grade 1: no resorption
 Grade 2 cementum resorption only
 Grade 3 cementum+dentine without pulp
 Grade4 puplal involvement
Factors to be considered in the treatment planning (RCSEng 2010 Husain and McSherry)
1. Age
2. General oral health
3. Patient cooperation
4. Intra-arch relationship
5. Inter-arch relationship (Crowding / spacing)
6. Position of canine (A-P, vert, horiz.)
7. Resoption of the adjacent

8. Clinical condition of the 3 itself
9. Clinical condition of the Cs
Treatment options
1. No treatment, observe and monitor
Indications
1. Patient does not want treatment
2. Medical contraindication
3. Canine very displaced, ie high and above roots of incisors
4. No evidence of resorption of adjacent teeth or other pathology
5. Ideally good contact between lateral incisor and first premolar wih good aesthetics
6. Good prognosis for the deciduous canine
 Radiographic monitoring should take place to rule out cystic formation (frequency unknown),
migration, resorption etc
2. Interceptive treatment
The principles of interceptive treatment for palatal canines are:
1. Remove any obstruction – this usually means removal of the deciduous canine
2. Ensure adequate space for eruption
Advantages
1. Good chance of improvement of 3
2. Reduce need for surgery
3. Reduce time for FA
4. Reduce risk of resorption
5. It’s only indicated if there is no root resorption.
Disadvantages
1. Not guarantee
2. Trauma to child
3. Loss of space

Evidences for interception of ectopic U3s
1. Extraction of c, Ericson and Kurol, 1988
• 46 consecutive ectopic palatally placed maxillary canines were studied.
• The children, 14 boys and 21 girls, were between 10 and 13 year.
• In (78%) the palatal eruption changed to normal after 12 months.
• It suggest that extraction of the primary canine is the treatment of choice in young individuals
(10-13 years) to correct palatally ectopically erupting maxillary canines provided that normal
space conditions are present and no incisor root resorptions are found.
2. Extraction of c in crowded and non-crowded cases, Power and Short, 1993
The only study for crowded cases
 39 consecutive patients of mean age 11.2 years.
 In general 62 % showed improvement in eruptive position.
 In crowded cases the success rate was 14% as opposed to 86% in un-crowded cases.
 Horizontal overlap of the nearest incisor was found to be the most significant factor. If this
exceeded half the tooth width, success was unlikely.
 The presence of crowding was found to affect adversely the favourable eruption of the canine.

3. Extraction of c compared to control in a spilt mouth study, Bazagani 2014
Objective: To evaluate the effect of the extraction of deciduous canines on palatally displaced
canines (PDCs), to analyze the impact of the age of the patient on this interceptive treatment, and
to assess the outcome of one-sided extraction of a maxillary primary canine on the midline of the
maxilla.
Materials and Methods: This study included 48 PDCs in 24 consecutive patients with bilateral
PDCs. The mean age of the patients at diagnosis was 11.6 years (standard deviation 1.2 years).
After randomization, one deciduous canine of each patient was assigned to extraction, and the
contralateral side served as control. The patients were then followed at 6-month intervals for 18
months with panoramic and intraoral occlusal radiographs.
Results: The rates of successful eruption of the PDCs at extraction and control sites were 67%
and 42%, respectively, at 18 months. The difference between the sites was statistically
significant, and the effect was significantly more pronounced in the younger participants. A
significant decrease in arch perimeter occurred at extraction sites compared to control sites
during the observation period. No midline shift toward the extraction side was observed in any
patient.
Conclusions: The extraction of the deciduous canine is an effective measure in PDC cases, but it
must be done in younger patients in combination with early diagnosis, at the age of 10–11 years.
Maintenance of the perimeter of the upper arch is an important step during the observation
period, and a palatal arch as a space-holding device is recommended.
4. Extraction and space opening, Olive, 2002
 Reported the treatment of impacted maxillary canines by the extraction of the deciduous canine
and creation of excess space for the impacted tooth.
 The space which was created was 1 cm with the incisors being proclined and displaced up to 3
mm across the midline.
 The results were impressive. 94% success rate.
5. HG and extraction Leonardi et al., 2004
3 groups:

 Extraction of C + HG (to increase arch length); 80% success
 Extraction of C only, (50% successful eruption of 3)
 Control group, 34% success
6. HG and extraction, Baccetti et al., 2008
• 3 groups
1) Xtn C + HG, group 2) 88% successful eruption of 3,
2) with Xtn of C only, 65% successful eruption of 3,
3) control, group 3) 36% successful eruption of 3
7. RME and extraction, Baccetti et al., 2009
 RME only 65.7%
 No treatment: 13.6% .
8. HG+RME+extraction, Armi & Baccetti, 2011
The randomized prospective design comprised 64 subjects
three groups:
1. rapid maxillary expansion and cervical pull headgear (RME/HG); successful eruption was 86 %
2. cervical pull headgear (HG); successful eruption was 83%
3. untreated control group (CG), successful eruption was (36%).
9. RME + transpalatal arch+extraction, Baccetti 2011
Results and Discussion:
 80 per cent for the RME/TPA/EC group,
 79 per cent for the TPA/EC group,
 62.5 per cent for the EC group,
 28 per cent in the CG

Conclusions: The use of a TPA in absence of RME can be equally effective than the RME/TPA
combination in PDC cases not requiring maxillary expansion, thus reducing the burden of
treatment for the patient.
10. Extraction of C and D, Bonetti 2011
50% of canines in the ECMG improved position by one sector and 13% by two sectors, while on
32% of the canines in ECG improved by one sector and none by two sectors.
The extraction of maxillary first deciduous molars, in addition to the deciduous canines, appears
to create more space and allow canines, at risk from impaction, to improve their position
spontaneously.
11. A systematic review, Kurol 2011
No evidence-based conclusions could be drawn due to the few studies identified, the
heterogeneity in study design, and the unequivocal results
12. Cochrane review, Parkin N, 2009 and 2012
There is currently no evidence to support the extraction of the deciduous maxillary canine to
facilitate the eruption of the palatally ectopic maxillary permanent canine. Two randomised
controlled trials (Baccetti 2008; Leonardi 2004) were identified but unfortunately, due to
deficiencies in reporting, they cannot be included in the review at the present time
Why 3 erupt after c exo?
1) Removal of obstruction
2) Presence of c might cause inflammation of 3 follicle causing its delaying in eruption and its
removal will resolve this problem
3. Surgical removal
Indication
1. Pathology of 3
2. Good contact bet 2 and 4
3. Good c

4. Sever impaction
5. Poor compliance
Disadvantages
1. Surgery can further compromise prognosis of C
2. Poor esthetic
3. Loss of canine eminence
4. Alveolar bone loss
Mechanics of subsequent orthodontic treatment in canine substitution
4 as a replacement for 3, apply;
1. mesiopalatal rotation
2. buccal root torque
3. grinding the 4 palatal cusp
4. Surgical exposure and orthodontic alignment
Indication
• When IO fails
• Available space for 3
• Favourable position of 3
• Pt motivation
• No pathology with 3 or 1 or 2
Disadvantages
1. Root resorption
2. Pulp obiltarion
3. Necrosis of teeth
4. Ankylosis
5. Fenestration and PD problems
6. Discontinuation of treatment

7. Relapse
Types of attachment
Many types of attachments can be placed on the tooth . These include the cast-gold inlay, the
ligature wire around the cervical part of the tooth, the direct bonded attachment , a screw
cemented in the crown , the placement of a wire in a filling , or a hole in the tip of the crown
through which to pass a ligature wire.( Andre Fournier 1982 )
Position of attachment
The position of attachment on the crown is very important because it determines, in part, the
direction and especially the type of movement the traction will induce . The more horizontally
the canine lies, the more occlusal the attachment must be to assure a proper tipping of the tooth
to a vertical position. In another spatial plane the proper placement of the attachment ( more
mesial or distal , buccal or lingual ) can help rotate a tooth. ( Andre Fournier 1982 )
Mechanically erupt a palatal canine
Fleming et al 2010 (JO)
A. Early treatment to facilitate canine eruption (auxiliary appliances)
 Sectional TMA spring with a palatal arch
 TAD Chaushu et al (2008)
 Archwires with loops
 Magnet: Magnets have also been used for traction of exposed PDC (Darendeliler 1997b). A
small magnet is bonded on the exposed and then covered canine. An attraction magnet embedded
in a upper removable appliance is used to generate force for canine traction.
 URA
 Opposing arch with intermaxillary elastic
 Elastomeric chain or string to main aw

 modified TPA with ballista spring: Jacoby (1979) described a ballista spring, which was inserted
in the buccal tubes of molar and premolar bands and attached to the impacted canine, to extruded
exposed canine. The advantages of ballista spring include the following:
I. vertical force on the exposed tooth
II. without compressing the impacted tooth toward the adjacent roots
III. controlled force (60-100gm with 0.016” spring, 120-150gm with 0.018” spring)
IV. easily modified
V. better aesthetics
 Catapult elastic
B. Treatment to mid-treatment mechanics to facilitate canine final alignment
 A thin continuous ligature wire
 Elastomeric traction to fixed appliance
 Piggyback NiTi archwires
 Nickel–titanium coil ligated to the canine in a similar fashion to elastomerics;
 Stainless steel archwire auxiliary
 Easy canine’ auxiliary for eruption of ectopic canine
 Maxillary lingual arch with a fairlead strut
the cuspid through the fairlead’s lumen. Maxillary
lingual arch with a fairlead strut (Fair-lead means a
pulley, thimble, etc., used to guide a rope forming
part of the rigging of a ship, crane, etc., in such a
way as to prevent chafing.) Johnson 2012. The

anteroposterior and occluso-gingival positions of the fairlead can be adjusted by bending the
strut at its base. Its bucco-lingual position can be adjusted by coiling or uncoiling the terminal
fairlead’s eyelet.
C. After exposing the canine, usually the movement to align 3 include:
1. Eruption either passive (3-6months) or active to move it away from roots of other teeth to reduce
the risk of resorptions and to prevent overgrowth of soft tissue
2. Then buccal movement
3. Then root torque
Open or closed surgical exposure? McSherry, 1996
A. Open exposure
Advantages
 Less bond failure
 No need for re-surgery
 Easy monitoring
 Better rotational control
Disadvantages
 More tissue removed and discomfort
 Infection
 Bone loss
 Poor esthetic
 Pd lig problem and gum recession
 Closed exposure
Advantages
 Less infection,
 Less bone exposure
 Rapid healing
 Better aesthetic

Disadvantages
 Re-surgery
 Uncontrolled movement
Evidences for open and closed exposure?
 There is no evidence to support one surgical technique over the other in terms of dental health,
aesthetics, and economics and patient factors. Parkin, 2008 (Cochrane)
Criteria to determine method of exposure, Kokich 2004
1. Labial or palatal or along the arch
2. Vertical position
3. Mesidistal position of canine over the 2 (if 3 overlaping 2 then apical repositiong is the best)
4. Amount of attached gingiva
The “tunnel technique”
Crescini A,ClauserC,Giorgetti R,Cortellini P,Pini PratoGP.Tunnel tractionof infraosseous
impactedmaxillarycanines.A three-yearperiodontalfollow-up.AmJOrthodDentofacial Orthop 1994;
105:61–72.32.
Crescini A,Nieri M,RotundoR, Baccetti T, CortelliniP,PratoGP. Combinedsurgical and
orthodonticapproachtoreproduce the physiologiceruptionpatterninimpactedcanines:Reportof 25
patients.IntJPeriodonticsRestorativeDent 2007;27:529–537.
In 1994, Crescini etal.(1994), proposedinthe internationalliterature the very favourableorthodontic
and periodontal resultsof the “tunnel technique”inrepositioning impactedcanines.A surgical-
orthodonticprocedure wasusedtotreatdeep infraosseousimpactedcanines(testteeth) associated
withthe persistence of the primarytoothin15 patientswhohad the contralateral canine normally
erupted(control teeth).The periodontal outcomewasevaluatedatthe endof the orthodontic
treatmentand3 yearslater.In the “tunnel technique”,afterextractionof the primarycanine,a
mucoperiostealflapwasraisedonthe buccal (sevencases) or palatal (eightcases) aspecttoexposethe
cusp of the impactedtooth.The empty socketof the primarytoothwasextendedtoreachthe impacted
cusp andto form an osseoustunnel.A chainwaspassedthroughthe tunnel andfixedtoabonded

device onthe impactedcusp.The flapwassuturedback intoitsoriginal position.The chain wasusedfor
tractionto the impactedcanine towardthe centerof the alveolarridge. Noattachmentlossandno
recessionwere observedatthe endof the active therapy or 3 years later.Nosignificantdifferencesin
keratinizedtissue widthwere observed betweentestandcontrol teethatthe follow-upexamination.
The purpose of a furtherstudybyCrescini etal (2007) was to evaluate the periodontal variablesof
impactedmaxillarycaninesthatwere treatedwithacombinedsurgical andorthodonticapproachaimed
at reproducingthe physiologiceruptionpatternof a largernumberof canineswithrespecttothe
original report.Twenty-five patientswhopresentedwithunilateral impactedmaxillarycanineswere
consecutively enrolled(age range,13.2to 23.2 years).They were treatedwithasurgical flapand
orthodontictractiondirectedtothe centerof the crest and were evaluated periodontallyatthe endof
treatmentandagainat a follow-upvisit(2to 5 years posttreatment).Pocketdepth,keratinizedtissue
width,and gingival recessionwere recorded.Atthe endof orthodontictreatment,all 25 treatedcanines
presentedwith normal pocketdepth(2.0± 0.3 mm) anda normal amountof keratinizedtissue (5.0±1.2
mm).Nositesshowedgingivalrecession.Atthe follow-upvisit,bothpocket depthsandkeratinized
tissueswere slightlyreduced.The combinedtechnique permitstractionof the impactedcaninestothe
centerof the crest,simulatingthe physiologiceruptionpatternandresultingincorrectalignmentand
goodperiodontal status.

Retention considerations after aligning maxillary impacted canines
The following measures are suggested to prevent relapse:
 Full correction of torque
 Early correction of rotations
 Pericision
 Bonded retainers
5. Transplantation, Moss, 1974
Indication
1. Failed IO
2. Pt willingness
3. Teeth for transplantation should have root development that is half to three-quarters complete.
4. Available space
5. No pathology
Disadvantages
1. Trauma
2. Rsorption
3. Ankylosis
4. Infection
NB:
• SURGICAL TECHNIQUE for transplant AS USUAL
• The use of template generated by CAD CAM system is valuable to prepare the receipt site before
transplantation (Cross 2013)
• If the position of the canine prevents orthodontic space regaring for future transplant, it is
recommended to extract the canine and park it under the mucosa until the space regain then
another surgery to transplant it again.
Success rates can be over 90% if transplanted into extraction socket

As low as 60% in artificially-formed sockets ( when tooth fully- developed)
6. Recommended approaches for the management of impacted and ankylosed maxillary canines
(Urebi 2013)
 Extraction of the ankylosed tooth followed by prosthetic replacement.
 Surgical luxation of the tooth followed by orthodontic traction.
 Osteotomy of the dentoalveolar segment with immediate repositioning of the dentoalveolar
structures.
 Osteotomy followed by intraoral distraction.
 Osteotomy followed by heavy orthodontic forces
 Osteotomy with partial repositioning followed by heavy orthodontic forces.

 Lingual corticotomy of the dentoalveolar segment, followed by a labial corticotomy three weeks
later and a conventional orthodontic force.
Treatment of buccaly ectopic canine
• IO+relief crowding and provide space, it will commonly erupt spontaneously
• FA to complete alignment
• Might need exposure either closed or apical repositioning
(Mitchell, 2007)
A treatment difﬁculty index for unerupted maxillary canines, Pitt, Hamdan and Rock, 2006
The prognosis for alignment of an impacted maxillary canine is affected by several factors
(McSherry, 1996 RCS England):
1. Horizontal position
2. Angulation to midline.
3. Vertical height.
4. Bucco-palatal position.
5. Age of patient.
6. Rotation.
7. Coincidence of arch midlines.
8. Alignment and spacing of the upper labial segment.
Result of this study, Difficulty score in order: (Almuzian ACRONYM HAV BARMA)

Conclusion:
 Unerupted canine is a common orthodontic problem. Palatally displaced canines (PDC)
contribute the majority of the total number of unerupted canines and impacted mandibular
canines are far less common. PDC is usually associated with anomalous or missing maxillary
lateral incisors while labial unerupted canines (maxillary and mandibular) are related to lack of
arch space. Many causative factors have been suggested in PDC. However, Lateral Incisors
Guidance Theory and Genetics Factors as Primary Origin attract the most of the attention.
 Assessment with palpation supplemented with radiographs are recommended above the age of 10
years old. Parallax technique is used to localize the unerupted canine.
 Complications of unerupted canines can be severe e.g. loss of maxillary lateral incisor due to
root resorption.
 Treatment options for unerupted canine include :
a) extraction of primary canine
b) no treatment
c) surgical removal of canine
d) surgical exposure with or without traction
e) autotransplantation.
 The decision should be based on :
a) age of the patient and development stage of the dentition
b) the position of the unerupted canine
c) other features of the malocclusion that may also require treatment
d) evidence of root resorption affecting the permanent incisors
e) the patient’s own perception of the problem and the amount of treatment that they are prepared
to undergo.
 Different surgical exposure techniques have been reported. Minimising periodontal
complication after surgery is a major consideration especially in cases with buccally impacted
canines. Different orthodontic methods of traction have also been reported. The use of light
forces to move the impacted tooth, creation and maintenance of sufficient space in the arch for

the impacted tooth and provision of anchorage during canine extrusion are the main principles in
applying traction to surgical exposed canine.

Impacted upper canines / for orthodontists by Almuzian

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