Mohammed Almuzian, University of Glasgow, 2014 Page 1
Impacted Upper Canines
1. Calcification commences at 4-5mths after birth.
2. 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
3. Upper erupts 11-12yrs
4. Lower erupts 9 -10yrs
5. 3's palpable in buccal sulcus by 8-10 yrs old (Ferguson, 1990)
1. Developmentally absent 3's: 0.08% (Brin et al, 1986)
2. Impacted 3's: 2% (Ericsson, 1986)
F:M = 70%:30%
Unilateral: bilateral = 4:1
Palatal: 61%; in line of arch: 34%; buccal: 4.5% (Mandal, 2000, Brin et al, 1986)
Associated with peg lateral incisors (Brin et al 1986)
High incidence associated with CI II div 2 malocclusions (Moosy, 1994)
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.
Mohammed Almuzian, University of Glasgow, 2014 Page 2
5. Resorption of canine itself can also occur.
6. Dentigerous cyst formation and infection with referred pain
7. Damage to adjacent teeth during surgery
1. General causes of failure of eruption and impaction
a. An long and tortious eruptive path
b. Trauma with displacement of tooth bud
c. Intra-alveolar Obstruction
Retained deciduous teeth
supernumerary tooth or odontome
Pathology, such as a dentigerous cyst
thickened mucosa following early extraction of deciduous teeth (particularly in
the lower premolar region)
2. Two main theories have been proposed
A. Guidance theory, evidences:
With small or developmentally absent lateral incisors, the incidence are three
Associated with peg lateral incisors (Brin et al 1986)
High incidence associated with CI II div 2 malocclusions (Moosy, 1994)
B. Genetic theory, polygenic inheritance, evidences: Peck
Occurrence with specific race
Occurrence in family
Occurrence in female more than male
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Occurrence with specific syndrome
Occurrence unilateral: bilateral is 4:1
Diagnosis unerupted teeth
Clinical signs of impacted 3s
Prolonged retained c
Absence of buccal budges at age of 10 years
Presence of palatal budges
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
1. Presence or absence of the canine
2. Overall stage of dental development
3. Local anatomic considerations
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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
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
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Chaushu and Becker (1999) have described a method of localising maxillary
canines using only a panoramic radiograph.
This depends on the fact that objects nearer the x-ray source (and further from the
film) project a larger image than objects closer to the film and further from the x-
ray source. So palatally positioned canine looks larger than adjacent or normal
contralateral if present.
It is not precise technique and more subjective than objective.
Sensitivity of this technique is 80%
III. Parallax technique (image/tube shift method, Clark’s rule, buccal object
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
The horizontal shift in the horizontal parallex is 10-20 degree
3. DPT overestimates the angulation and underestimates proximity to midline
4. Armstrong 2003 fond horizontal better than vertical parallex.
IV. CT spiral scanning
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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
Grade 1=0-15 degree,
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,
3. AP position of root apex
Zone 1=at area of 3,
zone 2=above 4,
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
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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
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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. Risk factors for resorption: Ericson & Kurol,1988
• 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
4. The following are not significant risk factors:
• Size of follicle,
• Quantity of deciduous canine root resorption
5. Aetiology of resorption:
• Active pressure during eruption.
• cellular activities in the tissues at the contact points.
Ericson & Kurol,2000 classified the resorption into:
Grade 1: no resorption
Grade 2 cementum resorption only
Grade 3 cementum+dentine without pulp
Grade4 puplal involvement
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Management , RCSEng 2010 Husain and McSherry
Factors to be considered in the treatment planning
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
1. No treatment, observe and monitor
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
6. Good prognosis for the deciduous canine
Radiographic monitoring should take place to rule out cystic formation
(frequency unknown), migration, resorption etc
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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
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.
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
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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
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.
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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.
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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
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
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%).
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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
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
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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
1. Pathology of 3
2. Good contact bet 2 and 4
3. Good c
4. Sever impaction
5. Poor compliance
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
4 as a replacement for 3, apply;
1. mesiopalatal rotation
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2. buccal root torque
3. grinding the 4 palatal cusp
Surgical exposure and orthodontic alignment
• When IO fails
• Available space for 3
• Favourable position of 3
• Pt motivation
• No pathology with 3 or 1 or 2
1. Root resorption
2. Pulp obiltarion
3. Necrosis of teeth
5. Fenestration and PD problems
6. Discontinuation of treatment
Mechanically erupt a palatal canine
Fleming, Sharma, 2010
A. Early treatment to facilitate canine eruption (auxiliary appliances)
1. Sectional TMA spring with a palatal arch
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2. TAD Chaushu et al (2008)
3. Archwires with loops
6. Opposing arch with intermaxillary elastic
7. Elastomeric chain or string to main aw
8. modified TPA with ballista spring
9. Catapult elastic
B. Treatment to mid-treatment mechanics to facilitate canine final alignment
1. A thin continuous ligature wire
2. Elastomeric traction to fixed appliance
3. Piggyback NiTi archwires
4. Nickel–titanium coil ligated to the canine in a similar fashion to elastomerics;
5. Stainless steel archwire auxiliary
6. Easy canine’ auxiliary for eruption of ectopic canine
7. 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.,
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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
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
1. Less bond failure
2. No need for re-surgery
3. Easy monitoring
4. Better rotational control
1. More tissue removed and discomfort
3. Bone loss
4. Poor esthetic
5. Pd lig problem and gum recession
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1. Less infection,
2. Less bone exposure
3. Rapid healing
4. Better aesthetic
2. 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
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 following measures are suggested to prevent relapse:
1. Full correction of torque
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2. Early correction of rotations
4. Bonded retainers
Transplantation, Moss, 1974
1. Failed IO
2. Pt willingness
3. Teeth for transplantation should have root development that is half to three-
4. Available space
5. No pathology
• 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.
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Success rates can be over 90% if transplanted into extraction socket
As low as 60% in artificially-formed sockets ( when tooth fully- developed)
Sectional osteotomy and Surgical repositioning
1. if pt unwilling for complex treatment
2. apex of canine needs to be in favourable position
3. ++ alveolar and palatal bone removed and canine swung
4. into place about fixed apex
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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
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.
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
Recommended approaches for the management of impacted and ankylosed
anterior maxillary teeth include: (Urebi 2013)
Extraction of the ankylosed tooth followed by prosthetic replacement.
Surgical luxation of the tooth followed by orthodontic traction.
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Osteotomy of the dentoalveolar segment with immediate repositioning of the
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.