SHY CANINE“Unveiling The

Hidden”

Author: Theertha Sudhakaran (CRRI)Guide: Dr. Ashwin Mathew George

Department of OrthodonticsSathyabama University Dental College &

Hospital

IMPACTION

• Impacted tooth is one that fails to erupt and will not attain its anatomical position beyond the chronological eruption date even after its root completion.

• Canines play a role in functional occlusion and form the foundation of an esthetic smile.

• As such, any factors that interfere with the normal development of canines and their eruption can have serious consequences

IMPACTED CANINE• Impaction of maxillary and mandibular canines is a

frequently encountered clinical problem.

• Maxillary canines are the most commonly impacted teeth, second only to third molars.

INCIDENCE• Maxillary canine impaction occurs in approximately 2%

of the population.

• Twice as common in females as it is in males.

• The incidence of canine impaction in the maxilla is more than twice that in the mandible.

• Of all patients who have impacted maxillary canines, 8% have bilateral impactions.

• . The prevalence of impacted maxillary canines varies and is reported as follows: 2%, 0.9% to 2%, 1% to 2%, 1.5% to 2%, 1% to 3%, with a palatal location 85% of the time and a labial location 15% of the time.

• Unlike buccal displacement of maxillary canines, palatal displacement of maxillary canines, and the frequent ensuing impaction, most often occurs in cases in which adequate perimeter arch space exists.

ETIOLOGY OF IMPACTED CANINE

•LOCALIZED•SYSTEMIC•GENETIC

LOCALIZEDTooth size- arch length discrepancies

Failure of the primary canine root to resorb

Prolonged retention or early loss of primary canine

Ankylosis of permanent canine

Cyst or neoplasm

LOCALIZEDDilaceration of the root

Absence of maxillary lateral incisor

Variation in timing of lateral incisor root formation

Iatrogenic factors

Idiopathic factors

SYSTEMICEndocrine deficiencies

Febrile diseases

Irradiation

GENETICHeredity

Malposed tooth germ

Presence of alveolar cleft

THEORIES OF CANINE IMPACTION

GUIDANCE THEORY

GENETIC THEORY

• Canine erupts along the root of lateral incisors, which serve as a guide, and if the lateral incisor is absent or malformed, the canine will not erupt.

GUIDANCE

THEORY

• Genetic factors are primary origin of palatally displaced maxillary canine and include other possibly associated dental anomalies, such as missing or small lateral incisor.

GENETIC

THEORY

SEQUELAE OF IMPACTED CANINE

Labial or lingual malpositioning of impacted tooth

Migration of neighbouring teeth and

loss of arch length

Internal resorption or external root resorption of impacted or neighbouring

tooth

Dentigerous cyst formation

Infection particularly with partial eruption

Referred pain

CLINICAL EVALUATION• Amount of space available in dental arch

for impacted canine is assessed in model.Study model

analysis

• Gives clue of position of impacted tooth.Morphology of adjacent tooth

• Canine bulge present buccally or palatally.Contours of

adjacent alveolar bone

• Root resorption. Mobility of adjacent tooth

RADIOGRAPHIC EXAMINATION• Indicated in individual with unerupted and non-palpable canines

after the age of 11 years.

• INTRA ORAL RADIOGRAPHS

• IOPA

• Occlusal

• EXTRAORAL RADIOGRAPHS

• OPG

• Lateral cephalometric

• DIGITAL IMAGING

• CT

• CBCT

INTRAORAL VIEWS

IOPA• Clark’s rule tube shift technique.• Locates canine positioned buccally or palatally to

other teeth in the arch.

OCCLUSAL RADIOGRAPHS• Determining position of canines relative to the

midline.

A periapical, panoramic, or occlusal view will not reveal the presence of a canine that is outside their fields of view.

EXTRAORAL VIEWS

OPG• Used to localize impacted teeth in all

three planes.

LATERAL CEPHALOMETRICS• Realtionship of impacted canine with

other facial structures can be studied.

superimposition in the anterior and palatal regions of the maxilla may mask the presence of a canine. In addition, the canine may not be adequately visualized with conventional imaging to correctly identify its position.

3 DIMENTIONAL IMAGING

• 3-dimensional imaging modalities provide a volume of information that can be used to assess and localize teeth within the entire maxilla and adjacent regions without the limitation of visualization with superimposed structures.

CT• Superior diagnostic tool.

• Early detection of root resorption.

• Accurate localization of impacted canine and visualization of associated structures.

CBCT• Identify and locate the position of impacted canine

accurately.

• Dentists can assess any damage to adjacent tooth roots and amount of bone surrounding each tooth .

DETERMINING THE PROGNOSIS• FACTORS INFLUENCING THE TREATMENT DECISION OF AN

IMPACTED CANINE

Age of patient

Availability of space

Favourable position of canine

Presence of adequate width of attached gingiva

POSITION OF CANINE

• CANINE ANGULATION TO MIDLINE.

• VERTICAL HEIGHT OF IMPCATED CANINE.

• POSITION OF THE CANINE APEX RELATIVE TO THE ADJACENT TEETH.

• MESIODISTAL POSITION OF CANINE TIP TO ADJACENT TOOTH.

MANAGEMENT OF IMPACTED CANINE

Interceptive treatment.

Treatment of labial impaction.

Treatment of palatal impaction

Methods of applying traction.

Retention consideration.

INTERCEPTIVE TREATMENT• When the clinician detects early signs of ectopic

eruption of canines, an attempt should be made to prevent their impaction and its potential sequelae.

• Selective extraction of the deciduous canines as early as 8 0r 9 years of age.

• Normalize the eruption of ectopicaly erupting permanent canine.

LABIAL IMPACTION OF UPPER CANINE

• Due to ectopic migration of canine crown over the root of lateral incisor or insufficient space in the arch caused by midline shift of dental origin.

• Arch length- tooth material discrepancy is the most common cause.

• Extraction of deciduous canine at early age of 8 or 9 years will enhance eruption and self correction of labial impaction.

Labial impaction

Initial orthodontic treatment was aimed at creating space in the maxillary arch with fixed appliance therapy.

Surgical exposure and orthodontic traction.

SURGICAL EXPOSURE• Indicated when tooth does not erupt spontaneously

after creating space in the arch.

• Attempted 6 months after the root formation

• Flap designs should preserve the band of attached gingiva and should guide tooth to erupt through its natural path of eruption.

OPEN TECHNIQUE

• Excisional approach

Canine crown coronal to

mucogingival junction

• Apically positioned flap

Canine crown apical to

mucogingival junction

CLOSED ERUPTION TECHNIQUE• Indicated if tooth is impacted in the centre of the

alveolus.

Flap is elevated

Attachment placed on impacted tooth

Ligature or chain placed over the attachment to activate after a week

Raised flap is repositioned in its original location

Permit eruption of impacted canine in normal direction

PATIENT 1

PRE OP

PRE OP

POST OP

POST OP

PERIODONTAL CONSIDERATION• Excisional technique must be parformed only when

sufficient gingiva is present, to provide atleast 2-3mm of attached gingiva over the canine crown after it has erupted.

• If crown is positioned mesially and over the root of the lateral incisor, the crown should be exposed completely with an apically positioned flap.

PALATAL IMPACTION OF UPPER CANINE

• Crown is surgically exposed, an attachment is bonded during the exposure, flap is sutured back, leaving a twisted ligature wire passing through the mucosa to apply orthodontic traction.

CLOSED ERUPTION

• A flap is raised, bone covering crown is removed, small window or fenestration is made, orthodontic attachment is bonded and flap is sutured in to place.

OPEN WINDOW

ERUPTION TECHNIQUE

PATIENT 2

PRE OP

PRE OP

POST OP

POST OP

METHODS OF APPLYING TRACTION

• Force elements

Ligature wire

Rubber bands

Elastomeric chains

Elastic threads

• Ballista springs (mouse trap loops)

• Magnetic forces

• Eyelet attachment

• TMA sectional arch wire

• Miniimplants

• Elastic traction using lower fixed or removable appliance as anchorage.

TUNNEL TRACTION TECHNIQUE

• For aligning deep infraosseous impacted canines.

• Osseous tunnel provided towards the centre of the alveolar ridge.

• Socket of deciduous canine can be used as tunnel, for movement of impacted canine.

RETENTION CONSIDERATIONRelapse of rotations and spacing may occur after completion of the

orthodontic treatment of an impacted canine.

SUPRACRESTALFIBROTOMY

FIXED RETAINERS

REMOVAL OF HALF MOON SHAPED WEDGE OF TISSUE ( To prevent lingual drift of palatally impacted canine)

CONCLUSION

• Various surgical and orthodontics techniques may be used to recover impacted maxillary canines.

• Proper management of these teeth requires appropriate surgical techniques to apply forces in a favourable direction and to have complete control for efficient correction, thereby avoiding damage to the adjacent teeth.

• The management of impacted canine is a complex procedure requiring a multidisciplinary approach.

• The clinician should communicate with each other to provide the patient with an optimal treatment plan based on scientific rationale.

ACKNOWLEDGEMENT

• GUIDE :Dr Ashwin Mathew George, Professor & Head

• Dr. V. Sudhakar, Reader

• Dr Shrinivaasan N. R, Senior lecturer

• Dr Xavier, Senior lecturer

• Dr Navaneetha, Senior lecturer

DEPT OF ORTHODONTICS.