|Year : 2017 | Volume
| Issue : 2 | Page : 124-128
Maxillary canine impaction to treat or not
Swet Nisha, Pratibha Shashikumar, Sourav Chandra
Department of Periodontology and Oral Implantology, JSS Dental College and Hospital, JSS University, Mysuru, Karnataka, India
|Date of Web Publication||28-Dec-2017|
Dr. Swet Nisha
JSS Dental College and Hospital, Room No. 9, Department of Periodontology, S.S. Nagar, Bannimantap, Mysuru - 570 015, Karnataka
Source of Support: None, Conflict of Interest: None
Management of impacted canine teeth requires early diagnosis and interception of the clinical situation. Various treatment modalities are available in literature, and the clinical situation may demand interdisciplinary approach. The treatment options should be time- and cost-effective with promising result both functionally and esthetically. This review article is an overview of etiology, diagnosis, and treatment modalities for the management of impacted canine.
Keywords: Canine impaction; etiology; surgical exposure
|How to cite this article:|
Nisha S, Shashikumar P, Chandra S. Maxillary canine impaction to treat or not. Indian J Multidiscip Dent 2017;7:124-8
| Introduction|| |
Impaction of teeth often occurs in the permanent dentition. The most frequently impacted teeth are the third molars, followed by the maxillary permanent canines with the prevalence of about 1.7% in Caucasians. Ectopic maxillary canines occur more often palatally (85%) than buccally (15%).
The ratio of prevalence of palatally impacted canines in Asian-to-European population is 5:1.
| Etiology of Canine Ectopia Is Illustrated below|| |
- Spaced arches
- Missing adjacent lateral incisor
- Anomalous/abnormal in shape and size of lateral incisor
- Late developing dentition
- Familial history.
There are localized, systemic, or genetic etiological factors that cause canine impaction. Early diagnosis by clinical and radiographic examinations is required for the prevention of impaction. The treatment approach is interdisciplinary and included no treatment, interceptive, extraction, autotransplantation, and surgical exposure followed by orthodontic alignment of the impacted canine. Each treatment has its own advantages and disadvantages, and the treatment planning should be focused on both esthetic and functional harmony.
Theories associated with canine impaction:
- According to the Guidance theory, the lateral root serves as a guide along which the canine erupts and when it is not present or malformed the canine fails to erupt 
- Peck et al. gave “The genetic theory” which states that the genetic factors are responsible for palatally displaced maxillary canines.
Sequelae of canine impaction can be:
- Root resorption
- Dentigerous cyst formation
- Referred pain.
Diagnosis comprises of clinical and radiographic examination:
| Clinical Signs|| |
Following clinical signs can be suggested as an indication for 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.
| Visual Examination|| |
The absence or abnormal position of both the canine bulge may be an indication of canine impaction [Figure 1]. When canine is not palpable in the buccal sulcus by the age 10–11 years or if any asymmetrical eruption patterns of canine are noted. The rate of treatment success is associated with early diagnosis and treatment of the palatally ectopic canine.
| Palpation|| |
Palpation of the buccal and palatal mucosa is recommended to assess the position of the erupting maxillary canines. The absence of the canine bulge or presence of asymmetrical eruption after the age of 10 years may indicate that the canine is ectopic.
| Radiographic Examination|| |
Radiographic examination includes intraoperative periapical radiograph using tube-shift technique and buccal object rule.
- Tube-shift technique – In this technique, two adjacent periapical radiographs of the impacted tooth are taken at slightly different horizontal angles. If the object moves in the opposite direction, it is buccally impacted. When the object moves in the same direction of the X-ray beam, it is palatally impacted
- In the buccal object rule, one periapical radiograph is taken normal angulation, whereas the second film is exposed at 20° vertical angulation of the cone. The buccal object will move in opposite direction to the source of radiation, and the lingual will move in the same direction.
Panoramic radiograph and occlusal radiograph can also be useful in giving relation of impacted canine to adjacent teeth. Cone-beam computed tomography showing three-dimensional image reduces dosage and pathology like ankylosis can be examined.
The correct localization of the impacted tooth is very critical for a proper treatment planning. Based on the location of impacted canine, proper surgical approach can be chosen and direction for the application of orthodontic forces can be decided.
| Treatment Planning|| |
As canine is referred as cornerstone of the mouth, proper alignment is not only essential for function but also attributes to esthetic smile line.
The clinician should consider the various treatment options available for the patient, including:
- No treatment
- Interceptive treatment
- Extraction of the impacted canine
- Autotransplantation of the canine
- Surgical exposure and orthodontic alignment.
No active treatment could be recommended when
- The patient does not request treatment
- There is no sign of resorption of adjacent teeth or other pathology 
- There is a severely displaced canine with no evidence of pathology
- Remote location from the dentition and ideally there is a good contact between lateral incisor and first premolar or good esthetics/prognosis for the deciduous canine.
Periodic recall and follow-up should be considered to avoid future complications such as root resorption or cystic degeneration in no active treatment cases.
The extraction of primary canine, in the late mixed dentition to prevent permanent canine impaction has been considered as an interceptive treatment as the primary tooth would represent a mechanical obstacle for permanent tooth eruption. Every attempt should be made for early diagnosis and prevention of impaction and its potential complications.
Radiographic examination of ectopically erupting maxillary canines in 35 children age group of 10–13 years old by Ericson and Kurol suggested 78 percent success in terms of rate and time (6–12 months) of spontaneous eruption of permanent canines after the extraction of primary ones. Maxillary expansion protocol as another treatment option in early mixed dentition period was suggested by Baccetti et al.
Extraction of the impacted canine
This is considered in the following situations 
- Patient declines active treatment and/or is happy with appearance
- There is evidence of early resorption of adjacent teeth
- The patient is too old for interception
- There is a good contact for lateral incisor and first premolar or the patient is willing to undergo orthodontic treatment to substitute the first premolar for the canine
- The impacted canine is ankylosed and cannot be transplanted
- The root of impacted canine is severely dilacerated
- Impaction is severe.
Surgical extraction of impacted canines and their substitution by first premolars eliminates all the risks and uncertainty related to orthodontic extrusion of an impacted canine.
Autotransplantation of the canine
Autotransplantation could be performed as a treatment option  when
- Interceptive treatment is inconvenient or has failed
- The degree of malocclusion is too severe to achieve orthodontic alignment, (crown tip mesial to the midline of the lateral incisor or mesial angulation >55°)
- Adequate space is available for the canine
- The prognosis is good for the tooth to be transplanted and it can be removed atraumatically
- Patient refuses a conventional orthodontic therapy
- Failure of orthodontic alignment due to immobility.
Autotransplantation may result in ankylosis, root resorption, and its prognosis in adults is poor. Schatz and Joho reported pulp vitality remained in 80% of 20 transplanted maxillary canine of patients aged 13–20 years.
Surgical exposure of teeth and orthodontic treatment
Two approaches could be followed after surgical exposure:
- surgical exposure to allow for natural eruption to occur
- surgical exposure with the placement of an auxiliary orthodontic appliance.
The main disadvantages of this approach are the spontaneous but slow canine eruption, the increased treatment time, and the inability to influence the path of eruption and the risk of ankylosing.
| Management of Labially Impacted Canines|| |
In general, three techniques are used for uncovering a labially impacted maxillary canine:
- Excisional uncovering (gingivectomy)
- Apically positioned flap
- Closed eruption techniques.
| Decision-Making|| |
The technique used for surgical exposure depends on:
- Location of impacted canine – vertical position – coronal or apical to the mucogingival junction and horizontal position – in relation to adjacent tooth. When the tooth is located coronal to the mucogingival junction, any three technique mentioned above can be chosen. Gingivectomy can be done only when the adequate width of keratinized tissue is present in the apical to the impacted canine. Closed technique can be chosen when the canine crown is positioned apical to the mucogingival junction as it will maintain the width of attached gingival [Figure 2] and [Figure 3]. Furthermore, apically positioned flap can be done, by placement of vertical releasing incision to allow for apical positioning of the keratinized tissue. Gingivectomy should not be done in such cases as it would result in no gingiva over the labial surface of the tooth after the eruption has completed.
- Amount of keratinized gingiva in the impacted canine area.
If adequate amount of attached gingiva is present for periodontal maintenance, any surgical technique can be used for exposure of impacted canine provided it does not cause loss of present attached gingiva. In case where there is no attached gingiva present or the procedure can cause loss of attached gingiva, first gingival augmentation procedures such as free gingival graft and double pedicle flap should be taken into consideration followed by canine exposure.
Compromised periodontal health can cause inflammation of tissues surrounding the impacted canine which can delay the eruption. An apically positioned flap can be chosen for the inadequate width of attached gingiva is present. However, some of the disadvantages of this technique are gingival scarring, intrusive relapse, and increased clinical crown length.
Advantages of the apically positioned flap are that it is minimally invasive, provides controlled tooth movement (even high in the vestibular depth), prevents cystic follicles, and decreases treatment time. If adequate amount of keratinized tissue exists closed technique can be chosen, though it increases treatment time and has diminished control of tooth.
Piniprato et al. has advised tunnel technique in cases of:
- Persistent deciduous canines exist with impacted canines or space available in the dental arch and
- Feasibility of direct traction of the impacted canine to the centre of the alveolar ridge.
| Management of the Palatally Impacted Canines|| |
The most commonly used surgical methods for exposing the impacted canine are:
- Surgical exposure and allowing for natural eruption
- Open surgical exposure and packing with subsequent bonding of an auxiliary
- Closed surgical exposure with the placement of an auxiliary attachment intraoperatively.
Location of the impacted canine in the dental arch, its relation to the adjacent teeth, and occlusal plane plays an important role in orthodontic treatment planning.
Various methods such as Ballista spring, tunnel traction, magnets, stainless steel, archwire auxiliary, Cantilever spring, Nickel-titanium closed-coil spring, TMA box loop, two archwire techniques, mandibular anchorage, K-9 spring, Australian helical archwire, monkey hook, and temporary anchorage devices have been used as traction methods for moving the canine into proper alignment.
Mostly two approaches are recommended in regards to the timing of attachment placement:
- A two-step approach – After surgical exposure of canine, the area is packed with a surgical dressing to avoid filling in of tissues around the tooth. After wound healing within 3–8 weeks, the pack is removed, then an attachment is bonded on the impacted tooth
- The second method is a one-step approach, in which the attachment is placed on the tooth at the time of surgical exposure. This method is especially recommended for palatally impacted teeth which aid the clinician to visualize and better control the direction of tooth movement when traction force is applied.
| Complications Observed With Unerupted Canine and Posteruption|| |
Even after surgical exposure the canine may not erupt when
- Insufficient bone removal is performed around the impacted canine
- Inappropriate orthodontic mechanisms
- Improper bonding.
Posteruption complications such as displacement and devitalization, ankylosis or loss of vitality, recurrent pain, cystic degeneration, invasive cervical root resorption, external root resorption of the canine and adjacent teeth.
| Conclusion|| |
Correct diagnosis and treatment plan plays an important role in the management of impacted canine. Esthetic and functional demand should be taken into consideration and whenever possible preventive treatment should be done. Various surgical approaches are mentioned in literature, accurate selection of the technique for the maintenance of periodontal health is necessary. The collaboration of both periodontist and orthodontist will help in practical and realistic treatment planning and patient's satisfaction.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Ericson S, Kurol J. Early treatment of palatally erupting maxillary canine by extraction of the primary canine. Eur J Orthod 1988;10;288-95.
Peck S, Peck L, Kataja M. The palatally displaced canine as a dental anomaly of genetic origin. Angle Orthod 1994;64:249-56.
Becker A. The defense of the guidance theory of palatal canine displacement. Angle orthod 1995;65:95-8.
Ericson S, Kurol J. Radiographic examination of ectopically erupting maxillary canines. Am J Orthod Dentofacial Orthop 1987;91:483-92.
Richardson G, Russell KA. A review of impacted permanent maxillary cuspids – Diagnosis and prevention. J Can Dent Assoc 2000;66:497-501.
McConnell TL, Hoffman DL, Forbes DP, Janzen EK, Weintraub NH. Maxillary canine impaction in patients with transverse maxillary deficiency. ASDC J Dent Child 1996;63:190-5.
Peck S, Peck L, Kataja M. Site-specificity of tooth agenesis in subjects with maxillary canine malpositions. Angle Orthod 1996;66:473-6.
Goho C. Delayed eruption due to overlying fibrous connective tissue. ASDC J Dent Child 1987;54:359-60.
Baccetti T, Mucedero M, Leonardi M, Cozza P. Interceptive treatment of palatal impaction of maxillary canines with rapid maxillary expansion: A randomized clinical trial. Am J Orthod Dentofacial Orthop 2009;136:657-61.
McSherry PF. The ectopic maxillary canine: A review. Br J Orthod 1998;25:209-16.
Schatz JR, Joho JR. A clinical and radiographic study of autotransplanted impacted canines. Int J Oral Maxillofac Surg 1993;22:342-6.
Kokich VG. Surgical and orthodontic management of impacted maxillary canines. Am J Orthod Dentofacial Orthop 2004;126:278-83.
Pini Prato G, Baccetti T, Giorgetti R, Agudio G, Cortellini P. Mucogingival interceptive surgery of buccally-erupted premolars in patients scheduled for orthodontic treatment. II. Surgically treated versus nonsurgically treated cases. J Periodontol 2000;71:182-7.
Vanarsdall RL Jr. Efficient management of unerupted teeth: A time-tested treatment modality. Semin Orthod 2010;16:212-21.
Crescini A, Clauser C, Giorgetti R, Cortellini P, Pini Prato GP. Tunnel traction of infraosseous impacted maxillary canines. A three-year periodontal follow-up. Am J Orthod Dentofacial Orthop 1994;105:61-72.
[Figure 1], [Figure 2], [Figure 3]