Impacted Canines: Our Clinical Experience.

BACKGROUND: To discuss the management of impacted canines and the various approaches used for the same.
MATERIALS AND METHODS: The data of 33 cases, with 43 impacted canine teeth, seen and operated over a period of 3-year in Santosh Dental College and Hospital has been compiled. The diagnostic methods and treatment modalities undertaken are described and discussed.
RESULTS: Canine impactions were more common in the maxilla as compared with mandible in our study, which was statistically significant. Impacted canine position was mostly palatal in maxilla and labial in mandible. Chi-square test yielded a p-value of 0.002 which shows that there is an association between arch and position. The treatment options used were surgical exposure and orthodontic repositioning, cyst enucleation with extraction of impacted canine and surgical removal of impacted canine.
CONCLUSION: Surgical exposure and orthodontic repositioning was successfully applied as first-line treatment for correcting ectopic positioned canine. In cases where exposure and subsequent orthodontic treatment was not indicated, the impacted canine was surgically removed to prevent future problems and surgical procedure was designed according to position of impacted canine.

INTRODUCTION

Impacted canine is not an uncommon clinical problem in dental patients. The permanent canines are developed deep within the jaws, complete their development late, and emerge into oral cavity after the neighboring teeth. Due to these circumstances, eruption disturbances are more common with canines than with other teeth, except for third molar.[1] Studies have reported that the incidence of tooth impaction varies from 5.6 to 18.8% of the population.[2-6] It is of concern that the method of diagnosis and the choice of treatment planning of this problem poses as a dilemma to the dental clinician. Maximum success with least complications and failures requires a systematic approach to each case.

We have reviewed 34 patients diagnosed with impacted canines. Each of these case had a detailed history followed by meticulous clinical and radiological examination to determine the exact site and position of the impacted tooth and to detect if any associated pathology was present in relation to the impacted tooth. This paper describes our approach for management and highlights the tips for successful management which can be applied as a protocol to each patient presenting with impacted canine.

MATERIALS AND METHODS

A total of 33 cases (13 males and 20 females) within the age group of 12 to 18 years, who were referred from the department of pedodontics, were included in this review. The criterion for a diagnosis of impacted canine included both clinical and radiological findings. The clinical elements which were suggestive of occurrence and location of impacted canine include:

Overretained deciduous canine.

Absent deciduous canine and resulting in loss of the available space for permanent tooth.

Tipping of lateral incisor in a vestibular or palatal position (Due to the pressure of the canine at its root).

Presence of a bump which can be felt by palpating the vestibular or palatal mucosa depending on the position of the retained canine. Clinically palpation of the buccal and palatal surface of the alveolar process distal to the lateral incisor may reveal the position of the maxillary canine about 1 to 1.5 years before emergence, and this has been suggested as a diagnostic tool.[1]

This was followed by radiologic examinations (IOPA/ orthopantomogram/occlusal view/paranasal sinus view/ dentascan) which were indispensable in diagnosing and locating the position of impacted canines (Figs 1 to 4). The etiologic factors observed in our study were arch length, tooth size discrepancy, accounting for 41% of cases, followed by overretained deciduous teeth, early loss of deciduous canine, cyst, trauma, cleft palate and cleidocranial dysostosis.

Fig. 1

Occlusal view of maxilla showing impacted right maxillary canine

Fig. 4

Dentascan showing bilateral impacted mandibular canines labially

The available treatment options were surgical removal of impacted canine (along with its associated pathology), or surgical exposure and orthodontic repositioning. Surgical removal of impacted canine was indicated if there was evidence of pathology around the tooth; if there was interference with planned orthodontic treatment; and if there was impingement on adjacent teeth. Exposure and orthodontic repositioning was carried out if space analysis revealed that tooth can be brought into occlusion and deviation of tooth axis was not too excessive (Table 1).

Table 1: Treatment modalities

		No. of cases (total 33)		Percentage		No. of teeth (total 43)		Percentage
Surgical removal of impacted canine		10		30.30		16		37.2
Surgical exposure and orthodontic treatment		15		45.45		18		41.8
Cyst enucleation with extraction of impacted canine		7		21.21		7		16.2
Surgical removal with fracture fixation		1		3.03		2		4.6

IOPA showing impacted maxillary canine

OPG showing bilateral impacted mandibular canines and left maxillary impacted canine

RESULTS

Statistical tests were applied to the descriptive data to detect any predilection for either arch and any preponderance of placement within the arch. Z test for comparing proportions yielded p-value of 0.000123 which is significant. Impacted canines are most commonly found in maxilla as compared with mandible (Table 2). Chi-square test yielded a p-value of 0.002 which shows that there is an association between arch and position. In maxilla, the impacted canine is in palatal position whereas in mandible, it is commonly located in labial position (Tables 3, 4 and Graph 1).

Table 2: Position of impacted teeth

Arch		No. of teeth (total 43)		Percentage
Maxilla		30		69.76
Mandible		13		30.23

Table 3: Arch vs position crosstabulation

Arch				Buccal/ vestibular		Palatal/ lingual		Intermediate		Unusual position		Total
Maxilla				7		19		2		2		30
				23.3%		63.3%		6.7%		6.7%		100.0%
Mandible		Count		8		0		3		2		13
		Percent within		61.5%		0.0%		23.1%		15.4%		100.0%
		according to arch
Total				15		19		5		4		43
				34.9%		44.2%		11.6%		9.3%		100.0%

Table 4: Statistical inference

		Value		df		Asymp. sig. (two-sided)
Pearson Chi-square		14.870		3		0.002
Likelihood ratio		19.700		3		0.000
Linear-by-linear		0.020		1		0.887
association
No. of valid cases		43

Graph 1

Arch vs position

The frequency of surgical approach was determined to show that the ease of access to the impacted canine is the main decisive factor (Figs 5 and 6). The operator should not be hesitant to use the combined approach wherever indicated (Tables 5 to 7).

Fig. 5

Clinical photograph showing palatal approach

Fig. 6

Clinical photograph showing buccal approach

Table 5: Surgical approaches

Approach		No. of teeth		Percentage
Labial/vestibular		19		44.19
Palatal		19		44.19
Combined (labial and palatal)		5		11.63
Total		43		100

Table 7: Statistical inference

		Value		df		Asymp. sig. (two-sided)
Pearson Chi-square		86.000		6		0.000
Likelihood ratio		83.591		6		0.000
Linear-by-linear		7.749		1		0.005
association
No. of valid cases		43

DISCUSSION

Canine impactions are more commonly associated with the maxilla than with the mandible; the same has been reported in our study which was statistically significant. One interesting finding seen in our study was the position of impacted canine in the two jaws that the impacted canine was mostly palatal in maxilla, whereas in the mandible it was more frequently seen in labial position. Chi-square test yielded a p-value of 0.002 which shows that there is a strong association between arch and position. According to Andreason,[1] 85% impactions are palatally located in the maxilla. Unusual positions seen in our study was the location of canine in symphysis, maxillary sinus and infraorbital regions. Bilateral representation of impacted canines was also observed.

To establish a diagnosis, several diagnostic methods have been adopted which include a variety of radiographs. IOPA radiographs with or without shift cone technique was the primary diagnostic modality in all our cases. As per requirement other radiographs, such as orthopantomogram, occlusal and PNS views, were advised. Recently in few cases, computed tomography was utilized to evaluate the impacted canines. Dentascan provided detailed information about exact position of canine, degree of crowding, incisor resorption and width of dental follicle.[7-10]

To treat a case of impacted canine, there can be various options ranging from keeping the patient under observation; surgical exposure and orthodontic repositioning; reimplantation and surgical relocation of impacted canine in the socket of the deciduous canine; to surgical removal of the impacted canine (Figs 7 to 11).

Fig. 7

OPG showing horizontally impacted right maxillary canine

Fig. 11

Primary wound closure

The factors that need to be evaluated before the mode of treatment of impacted tooth is decided, include the patient’s age, dental status of adjacent teeth (including periodontal, endodontic and operative status, shape and resorption), dental status of the impacted tooth, occlusal relationship, presence of any other associated condition (e.g. trauma/cyst/ odontoma) and arch length.[11-14]

Surgical exposure and orthodontic repositioning was considered the treatment of choice in all those cases wherever it was clinically feasible and a predictable and successful outcome could be obtained. The prognosis for orthodontically assisted eruption and repositioning of an impacted tooth within the alveolar process depends on the position and angulation of the impacted tooth, the length of treatment time, the patient’s age, degree of patient cooperation, the available space in the arch and the presence of keratinized gingival tissue.[15-17]

Flap raised and marking done

Impacted canine exposed and sectioned

Removal of the tooth after sectioning

In cases, where exposure and subsequent orthodontic treatment was not indicated, the impacted canine was surgically removed to prevent future problems and surgical procedure was designed according to position of impacted canine.

After tooth impaction is diagnosed and if a decision to not undertake any immediate intervention is made, it is recommended that periodic observation is done to rule out possible pathological sequelae. During this observation period, clinicians must perform clinical and radiologic examinations after every 18 to 24 months. The following pathological sequelae associated with tooth impaction have been noted: Dentigerous cyst, odontogenic keratocyst, adenomatoid odontogenic tumor, calcifying epithelial odontogenic (Pindborg) tumor, odontogenic myxoma, ameloblastoma, external/internal resorption of the impacted tooth, external root resorption of adjacent teeth, transmigration, referred pain and periodontitis.[1118-27]

Therefore, when decision is to retain an impacted tooth clinician must be vigilant for the potential development of a dentigerous cyst or ameloblastoma. The excised cyst/tissue should always be submitted to pathologist for microscopic examination for diagnosis.

CONCLUSION

In our study, canine impactions were more common in the maxilla as compared with the mandible which is statistically significant. Our study also shows that impacted canine position is mostly palatal in maxilla and labial in mandible. The crosstabulation shows that there is a strong association between arch and position. As the sample size was less, we need to study more number of cases to establish that such a correlation exists. Radiographs play a major role in diagnosing and determining the position of impacted canine. This further helps in deciding the approach to be used, i.e. labial, palatal or combined surgical approach. Various options can be used to manage a case of impacted canine. Surgical exposure and orthodontic repositioning was considered the treatment of choice. In cases where exposure and subsequent orthodontic treatment was not indicated, the impacted canine was surgically removed to prevent future problems and surgical procedure was designed according to position of impacted canine. We did not find any difference in complication rate between the palatal or buccal or combined approach.

Table 6: Surgical approach vs position crosstabulation

						Position
Approach				Buccal/ vestibular		Palatal/ lingual		Intermediate		Unusual position		Total
Labial/				15		0		0		4		19
vestibular				78.9%		0.0%		0.0%		21.1%		100.0%
Palatal		Count		0		19		0		0		19
		Percent within		0.0%		100.0%		0.0%		0.0%		100.0%
		surgical approach
Combined				0		0		5		0		5
(labial				0.0%		0.0%		100.0%		0.0%		100.0%
and palatal)
Total				15		19		5		4		43
				34.9%		44.2%		11.6%		9.3%		100.0%