CANINE IMPACTIONCanine Impaction

PRESENTED BY –PUNIT DUBEY

DEFINATIONSTHILANDER AND JAKOBSSON DEFINED AN IMPACTED TOOTH AS ONE WHOSE ERUPTION IS CONSIDERABLY DELAYED AND FOR WHICH THERE IS CLINICAL OR RADIOGRAPHIC EVIDENCE THAT FURTHER ERUPTION MAY NOT TAKEPLACE (THILANDER AND JAKOBSSON, 1968).

IN EARLY 1954 MEAD HAS DEFINED AN IMPACTED TOOTH AS A TOOTH THAT IS PREVENTED FROM ERUPTING INTO POSITION BECAUSE OF MALPOSITION, LACK OF SPACE, OR OTHER IMPEDIMENTS.

Etymology:

1739 from Latin impactionem “stricking against”

Etymology:1739 from Latin impactionem ”stricking against”

Later Peterson characterized impacted teeth as those teeth that fails to erupt into the dental arch within the expected time.

In 2004 Farman wrote that impacted teeth are those teeth that prevented from eruption due to a physical barrier within the path of eruption.

Introduction

The permanent maxillary canines develop deep within the maxilla, complete their development late and emerge into the oral cavity after the neighbouring teeth have erupted.

Due to these circumstances, eruption disturbances are more common with maxillary canines than with other teeth, except for third molars.

Unerupted canines occur 20 times more frequently in maxilla than in mandible.

They are almost rotated from 60 to 90 degree on their longitudinal axes.

Natural development

Mineralization of the primary canine starts at 4 - 12 months of age and is complete by 6 - 7 years of age.

During eruption the canine moves down along the distal aspect of the lateral incisor, not in very close contact with it.

The palpation of the buccal surface of the alveolar process distal to the lateral incisor may reveal the position of the maxillary canine about 1-1/2 yrs before its emergence.

During the active phases of eruption i.e. 1 - 2 years before oral emergence, the width of the dental follicle increases, whereas the size of the follicle decreases in cases of impacted teeth.

Aside from their importance in ideally mutually protected occlusalscheme ,the maxillary canine also plays role in esthetics and continuity of dental arch.

Incidence:

The prevalence of noneruption or ectopic eruption of maxillary canine is reported to a range from 0.8% to 2.9% depending on population examined where 8.0%to 10 % of these cases are bilateral.

It is seen with a higher frequency in females as compared to males.

Most commonly, it is found unilaterally. The most common position of the impacted canine is palatal to the lateral incisor and only in 15% of the cases it is seen buccally.

Nordenram and stomber(1966)in an examination of 500 impacted maxillary canine found 270 in horizontal plane in palate ,170 labially placed and 60 in dental ach.

.K. SAJNANI, N.M. KING / JOURNAL OF CRANIO-MAXILLO-FACIAL SURGERY 40 (2012) E375-E385

CLASSIFICATION

According to axial inclination

Class I: Impacted canine located in the palate

Horizontal

Vertical

Semi-Vertical

Class II: Impacted canine located in the buccal side

Horizontal

Vertical

Semi-Vertical

Class III: Impacted canines located in both palatal as well as buccal alveolar bone.

Class IV: Impacted canines located vertically between incisors and premolars

Class V: Impacted canines located in edentulous maxilla

Class VI when canine is placed in abnormal position,antral wall,infraorbital region

According to Field and Ackerman(1935)

a. Labial position

(1) crown with intimate relationship with incisors

(2) crown well above apices of incisors

b. Palatal position

(1) Crown near surface in close relationship to root of incisors

(2) Crown deeply embedded in close relationship to apices of incisors

a. Intermediate position

(1) Crown between lateral incisor and first premolar root

(2) Crown above of these teeth with crown labially placed and root palatallyplaced,or vice versa

a. Unusual position

(1) In nasal or antral wall

(2) In infraorbital region

1) Tooth size–arch length discrepancies.

2) Failure of the primary canine root to resorb.

3) Prolonged retention or early loss of the primary

canine.

4) Ankylosis of the permanent canine.

5) Cyst or neoplasm.

6) Dilaceration of the root.

7) Absence of the maxillary lateral incisor

8) Variation in root size of the lateral incisor.

9) Variation in timing of lateral incisor root

formation.

10) Iatrogenic factors.

11) Idiopathic factors.

ETIOLOGY

LOCALIZED FACTORS

SYSTEMIC FACTORS

1) Endocrine deficiencies.

2) Febrile diseases.

3) Irradiation.

GENETIC FACTORS

1) Heredity.

2) Malposed tooth germ.

3) Presence of an alveolar cleft

NEUOROLOGICAL SYMPTOMS

INDICATION FOR EXTRACTION

1. Change in position of adjacent tooth

2. Resorption of root of adjacent tooth

3. Cyst formation

4. Cleft palate

5. In edentulous patient

6. Neurological symptoms

Poor esthetics associated with primary canines

Loss of vitality of the incisors can occur

Late resorption of the unerupted canine itself

Referred pain

Eruptions

Infections particularly associated with partial

Neighboring teeth

External root resorption of the impacted as well as

Dentigerous cyst formation

Internal resorption

Arch length

Migration of neighboring teeth and resultant loss of

Labial or lingual mal-positioning of impacted tooth

SEQUELE OF IMPACTIONS: Shafers et al suggested that the following sequel might be associated with canine impaction.

Diagnosis of Canine Impaction

The clinician can investigate the presence and position of the cuspid using 3 simple methods: visual inspection, palpation and radiography

visual inspection

Palpation Radiography

Visual Inspection

Clinical signs that may indicate ectopic or impacted succedaneouscanines include lack of a canine bulge in the buccal sulcus by the age of 10 years, over retained primary canines, delayed eruption of their permanent successor and asymmetry in the exfoliation and eruption of the right and left canines.

Primary canines that are retained beyond the age of 13 years .

Clinical Evaluation

•It has been suggested that the following clinical signs might be indicative of canine impaction•Delayed eruption of the permanent canine or prolonged retention of the deciduous canine beyond 14–15 years of age•Absence of a normal labial canine bulge•Presence of a palatal bulge and•Delayed eruption, distal tipping, or migration (splaying) of the lateral incisor.

PalpationPalpation of the buccal and lingual mucosa, using the index fingers of both hands simultaneously, is recommended to assess the position of the erupting maxillary canines.

ERICSON S, KUROL J. LONGITUDINAL STUDY AND ANALYSIS OF CLINICAL SUPERVISION OF MAXILLARY CANINE ERUPTION. COMMUNITY DENT ORAL EPIDEMIOL. 1986;14:112–6.

According to Ericson and Kurol, the absence of the “canine bulge” at earlier ages should not be considered as indicative of canine impaction. In their evaluation of 505 schoolchildren between 10 and 12 years of age, they found that 29% of the children had nonpalpable canines at 10 years, but only 5% had it at 11 years, whereas at later ages only 3% had nonpalpablecanines. Therefore, for an accurate diagnosis, the clinical examination should be supplemented with a radiographic evaluation.

BISHARA SE. IMPACTED MAXILLARY CANINES: A REVIEW. AM J ORTHODDENTOFACIAL ORTHOP. 1992;101:159–71

Radiographic Evaluation

Although various radiographic exposures including occlusal films, panoramic views, and lateral cephalograms can help in evaluating the position of the canines, in most cases, periapical films are uniquely reliable for that purpose.

Periapical films

A single periapical film provides the clinician with a two-dimensional representation of the dentition. In other words, it would relate the canine to the neighboring teeth both mesiodistally and superoinferiorly. To evaluate the position of the canine buccolingually, a second periapical film should be obtained by one of the following methods.

Tube-shift technique or Clark's rule or (SLOB) rule

Two periapical films are taken of the same area, with the horizontal angulation of the cone changed when the second film is taken. If the object in question moves in the same direction as the cone, it is lingually positioned. If the object moves in the opposite direction, it is situated closer to the source of radiation and is therefore buccally located.

Buccal-object rule

If the vertical angulation of the cone is changed by approximately 20° in two successive periapical films, the buccal object will move in the direction opposite to the source of radiation. On the other hand, the lingual object will move in the same direction as the source of radiation. The basic principle of this technique deals with the foreshortening and elongation of the images of the films.

Occlusal films

Also help to determine the buccolingual position of the impacted canine in conjunction with the periapical films, provided that the image of the impacted canine is not superimposed on the other teeth.

Extraoral films

Frontal and lateral cephalograms

These can sometimes aid in the determination of the position of the impacted canine, particularly its relationship to other facial structures (e.g., the maxillary sinus and the floor of the nose).

Panoramic films

These are also used to localize impacted teeth in all three planes of space, as much the same as with two periapical films in the tube-shift method, with the understanding that the source of radiation comes from behind the patient; thus, the movements are reversed for position.

CT/CBCT

Clinicians can localize canines by using advanced three-dimensional imaging techniques. Cone beam computed tomography (CBCT) can identify and locate the position of impacted canines accurately. By using this imaging technique, dentists also can assess any damage to the roots of adjacent teeth and the amount of bone surrounding each tooth. However, increased cost, time, radiation exposure, and medicolegal issues associated with using CBCT limit its routine use.

The proper localization of the impacted tooth plays a crucial role in determining the feasibility of as well as the proper access for the surgical approach and the proper direction for the application of orthodontic forces.

In a study, Liu and colleagues7 used CBCT to evaluate variations in location of impacted maxillary canines. They found that the position of impacted maxillary canines varies greatly. Reports of maxillary canine impactions vary considerably in orientation, and CBCT provides information to dentists so that they can properly manage impacted canines surgically and orthodontically.

ALQERBAN ET AL-CBCT IMAGE OBTAINED WITH SCANORA 3D SHOWING OF AXIAL, SAGITTAL, CORONAL SLICES AND THE 3D MODEL THAT WERE USED IN THE FIRST EVALUATION SESSION TO IDENTIFY THE 0.300-MM RESORPTION DEFECT IN THE MAXILLARY LEFT LATERAL INCISOR.

E. Abdel-Salam et al.

ALQERBAN ET AL- THREE-DIMENSIONAL IMAGE FROM GALILEOS 3D COMFORTOF THE CHILD CADAVER SKULL IN THE EARLY MIXED DENTITIONSHOWING AN IMPACTED MAXILLARY LEFT CANINE IN CONTACTWITH THE ROOT SURFACE OF THE MAXILLARY LATERAL INCISOR.

3D illustration of the image-based CT coordinate system in Voxim

S. Hanke et al. / Journal of Cranio-Maxillo-Facial Surgery 40 (2012) e268ee276

COMPLICATION AFTER IMPACTION

1. Resorption of incisor roots.

2. Follicular cysts.

3. Tumorous change in follicle .

4. Marginal break down of supporting bone.

.K. SAJNANI, N.M. KING / JOURNAL OF CRANIO-MAXILLO-FACIAL SURGERY 40 (2012) E375-E385

Treatment Planning

Each patient with an impacted canine must undergo a comprehensive evaluation of the malocclusion.

The clinician should then consider the various treatment options available including the following

•No treatment if the patient does not desire it. In such a case, the clinician should periodically evaluate the impacted tooth for any pathologic changes.

•Prophylactic Space augementaion

•Age of individual and dental maturation.

•Space condition

•Position of canine

•Patient demand for treatment

It should be remembered that the long-term prognosis for retaining the deciduous canine is poor, regardless of its present root length and the esthetic acceptability of its crown. This is because, in most cases, the root will eventually resorb and the deciduous canine will have to be extracted.

•Autotransplantation of the canine.

•Extraction of the impacted canine and movement of a first premolar in its position.

BISHARA SE. IMPACTED MAXILLARY CANINES: A REVIEW. AM J ORTHODDENTOFACIAL ORTHOP. 1992;101:159–71

•Surgical exposure of the canine and orthodontic treatment to bring the tooth into the line of occlusion. This is obviously the most desirable approach.

•Prosthetic replacement of the canine.

•Extraction of primary canine

LABIAL APPROACH (SOURCE ARCHER. H. W., 1966)

RADIOGRAPH SHOWING IMPACTED MAXILLARY CANINES.RIGHT CANINE IS LOCATED LABIALLY WHILE LEFT CANINE ISLOCATED PALATALLYCLINICAL PHOTOGRAPH OF THE LABIAL AREA WHERE THERIGHT CANINE OF THE CASE SHOWN IS LOCALIZED

SURGICAL PROCEDURE FOR REMOVAL OF RIGHT IMPACTEDCANINE. A TRAPEZOIDAL INCISION IS CREATED BUCCALLYREFLECTION OF THE MUCOPERIOSTEAL FLAP

WITH PARTIAL BONE

Extraction Using Palatal Approach

Surgical Problem

Anesthesia

Apex deflection

Accidental nasal perforation

POSTOPERATIVE TREATMENT

After Debridment and closure of incision the wound heals uneventfully

1. A post op radiograph is desirable

2. Cold application to face prevents disfiguring swelling and edema

3. Antibiotics are generally not necessary unless there is preexisting infection or the antrum or nasal cavity has been opened.

4. Medication should be prescribed for pain.

A proposed classification for the surgical

approach of maxillary impacted canines

Classification Location Surgical technique

I Palatal Gingivectomy

II Center of alveolar ridge Repositioned flap

or labial

III Labial to long axis of adjacent Apically positioned flap

lateral incisor root

MANDIBULAR CANINES

NATURAL DEVELOPMENT

The mandibular canine develops from dental lamina lingual to primary canine with tooth germ close to base of mandible.

Eruption starts and emergence can be expected to be complete at the age of 9.6 to 10 years .

CLASSIFICATION According to Field and Ackerman(1935)

a. Labial position

(1) Vertical

(2) Oblique

(3) horizontal

b. Unusual position

(1) At inferior border

(2) In mental protuberance

(3) Migrated to opposite side

Natural courseMost of these teeth remains asymptomatic and without pathology.

Follicular cysts may develop and lead to severe displacement of canine.

Occasional periodontal infection may occur.

RADIOGRAPHIC DIAGNOSISIntraoral and panoramic radiograph usually provide a good overview

Of position of tooth

If surgical treatment is required ,a supplementary lateral exposure is needed to verify buccolingual position

SURGICAL ANATOMY

Lingual cortical bone in mandibular canine region is very thick, whereas buccal bone is rather thin.

Impacted canines are usually located mesial or distal to the canine region.

A buccal flap has to be raised and this will usually result in insertion of incisive and mentalis muscle

A lower incisive muscles inserts at the height of caniniealveolus where as mentalis muscle arises from mental fossa.

TREATMENT PLANNING

Four treatment approaches exit:

1. Observation

2. Exposure and orthodontic repositioning

3. Surgical repositioning

4. Surgical removal

REFLECTION OF THE FLAP,WHICH ENSURES SATISFACTORY ACCESS TO THE SURGICAL FIELD, NECESSARY DUE TO THE PRESENCE OF ODONTOMAS, OTHER THAN THE IMPACTED TOOTH.

Trapezoidal incision extending fromthe left lateral incisor as far as the first premolar of the opposite side of the mandible.

EXPOSURE OF THE CROWN OF THE IMPACTED TOOTH USING A SURGICAL BUR. A DIAGRAMMATIC ILLUSTRATION. B CLINICALPHOTOGRAPH

Luxation using the blade of the elevator alternately on the mesial and distal aspects of crown of tooth.

SURGICAL FIELD AFTER REMOVAL OF THE IMPACTED TOOTH AND ODONTOMAS.

POSTOPERATIVE TREATMENT

After Debridment and closure of incision the wound heals uneventfully

1. A post op radiograph is desirable

2. Cold application to face prevents disfiguring swelling and edema

3. Antibiotics are generally not necessary unless there is preexisting infection or the antrum or nasal cavity has been opened.

4. Medication should be prescribed for pain.

Post operative complications

Secondary hemorrhage may occur from incisive canals with persitentarterial bleeding.

A breakdown of blood clot and infection of wound are rare.

If they do occur ,the wound is irrigated daily unitl it has healed.