Combined Surgical and Orthodontic Treatment of Impacted Maxillary Canines

8/6/2019 Combined Surgical and Orthodontic Treatment of Impacted Maxillary Canines

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COMBINED SURGICAL AND ORTHODONTICTREATMENTOF IMPACTED MAXILLARYCANINES

Wissam Marzouk, BDS, MSc, PhD*; K.M. Ragai ElMostehy, BDS, FDSRCS**;

Abdullah Al-Qurashi, BDS, MS***

Positional variations of the maxillary cuspid are frequently encountered in dental practice. In such cases, because

of its devious path to reach its position in the arch, it often gets impacted and becomes difficult to bring into

occlusion. Both the orthodontist and surgeon should aim at early diagnose, schedule a plan, surgically expose the

cuspid and use all acceptable orthodontic mechanics to bring it into occlusion. Sixty-six cases of unerupted

maxillary canines were treated by two different surgical exposures and methods (window and open-closed flap

techniques) and were orthodontically moved into occlusion. The etiology, diagnosis and evaluation of the

impaction, as well as the possible orthomechanics used to arrange the canine's position, need a clear

understanding to plan a final treatment. The findings of this study showed that buccally-impacted canines are

more common and to reach occlusion more quickly than palatally-impacted canines. The axial inclination of the

palatally impacted canines with the Frankfort horizontal plane has a direct effect upon the rapidity of treatment.

The window surgical technique was found to be more convenient to the surgeon, orthodontist and patient.

Introduction

The positional variations that the maxillary cuspid adopts

are frequently encountered in orthodontic practice. While

bringing the unerupted maxillary canine into the dental arch

could be difficult, the therapist's diagnostic and treatment plan

should be in the best interest of the patient.

Incidence of impaction of the maxillary canine rank second

to that of third molar impaction.1'2

In any orthodontic practice

the anticipation of problems related to maxillary canine

impaction should be kept in consideration by early diagnosis.

Early referral to the proper specialist is mandatory where

Received 16/01/96; revised 06/08/96 and 29/11/96, accepted 18/12/96* Consultant Orthodontist, Dental Department, King Fahd

National Guard Hospital

** Professor of Periodontics & Consultant, Dental Department,King Fahd National Guard Hospital

*** Oral & Maxillofacial Surgeon and Consultant, King FahdNational Guard Hospital, Jeddah, Saudi ArabiaAddress reprint requests to : Dr. A. Al-Qurashi

The Saudi Dental Journal, Volume 9 Number 2, May - August 1997.

certain interceptive measures could be instituted so as to

diminish further complications such as incisal root

resorption4'5or cystic degeneration

6.

In reviewing the etiological factors that lead to maxillary

canine impaction, it is generally accepted that the devious path

it follows during its eruption and the long period of its

development play a great role in its impaction.2'7

Although

crowding has been implicated,3

this factor has been neglectedby several authors. Among other causes of canine impaction is

heredity where several members of the same family are

affected. Cystic degeneration around unerupted canines might

cause their impaction.10

Bishara5

and Isiekwe et al14

listed the most common cause

that participate in maxillary canine impaction such as

tooth-size, arch length discrepancy, prolonged retention or

early loss of deciduous canines, ankylosis of the developping

canine, presence of alveolar clefts, root dilaceration of the

develoipng canine, cystic degeneration of the enamel organ of


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SURGICALAND ORTHODONTIC TREATMENT 91

the canine during its eruption, iatrogenic etiology and

idiopathic maxillary canine impaction.

This study was to review the causes of maxillary canine

impaction and to present 66 cases treated surgically by two

different surgical approaches and orthodontically moved intotheir respective positions in the arch.

Materials and Methods

This study comprises 66 patients who sought dental

treatment in King Fahd General Hospital Dental Department,

Jeddah, Kingdom of Saudi Arabia. Not all the patients came

for orthodontic treatment but have been referred for other

dental problems. Their ages ranged from 13 to 19 years. All

impacted maxillary canines were accidentally discovered

through the routine clinical and radiographic investigations.

Hence, such cases were referred to the Orthodontic Unit for

further investigations and treatment.Patients were clinically, radiographically and

cephalometrically evaluated and findings were documented.

Clinical photographs were taken and study models were made

on each patient.

The position of the impacted canine was determined by

either palpation or location on lateral cephalometric as well as

intraoral occlusal radiogprahs [Figs. 1,2]. Another method used, which some authors consider superior to cephalostats in

locating the impacted canine, is the parallax technique. Two or

more periapical radiographs were taken in the same area,

shifting the tube horizontally between exposures. In this

investigation, the cross-sectional occlusal radiographs as well

as cephalostat technique yielded the best localization of

impacted canine.

The lateral cephalometric radiographs were traced and the

skeletal and dental cephalometric angles were measured to

decide whether a case would require extraction mechanics or

not. Moreover, the palatally impacted canines were traced and

the angle formed by its long axis and Frankfort horizontal plane

was measured in an attempt to find a relation between the axial

inclination of the impacted canine and the period it would take

to descend to occlusion [Figs. 3].

To complete orthodontic records, upper and lower alginate

impressions were taken and poured in stone to serve as primary

and study models for each use. Once the line of etreatment was

reached, the patients were divided orthodontically into two

groups. The first group was the extraction cases for which the

maxillary first premolars were to be extracted and the second

group were the non-extraction cases for which repositioning of

the impacted canines was the only procedure performed after

its surgical exposure.

Patients space establishment were referred to have

restorations, scaling and oral hygiene instructions and

extractions of premolars for the first group.

The patients were scheduled for bracketing and bonding to

start the active orthodontic tooth movement. The brackets were



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standard stainless steel Edgewise brackets with 0.022" slot.

The bands used were double tubed bands, the cervical round

tube for extra-oral force application if required and the other

rectangular tube for the arch wire.

Treatment for both groups was started by aligning andlevelling the teeth by nickle titanium arch wires starting by

round 0.014" followed by 0.016" then by 0.18". At times the

teeth were so irregular that to commence treatment, 0.012"

round nickle titanium wire was used. A round 0.018" stainless

steel wire was then placed with first order bend to complete

alignment.

In the first group (extraction cases), the patients were

scheduled for surgical exposure of the canines by either

procedure mentioned below. In the second group

(non-extraction), spaces were created for the impacted

canines. In those instances where there was retained

deciduous canines and some spaces between teeth, an elastic

chain over a rectangular 0.018"x0.022" stainless steel wire

and/or push coil between lateral incisor and first premolar was

used until a suitable space was created.

In cases of Class I subdivision malocclusion where there

was a unilateral mesial shift of posterior teeth, Class II elastics

(1/4" medium pull) were used on that side over the maxillary

first premolar and mandibular first molar with a lower lingual

arch for maximum anchorage. In the case with bilateral canine

impaction, there was absolutely no space for ethem and the

molars were in Class II malocclusion. A cervical face bow

was used over the first molar until enough space was created

bilaterally [Fig. 4a,b,c,]. Finally, the patients were ready for

surgical interference.

Surgical Procedure

Surgical exposure of the impacted canine was done in

either of two ways without any criteria of selection. The first

method was the open-closed flap technique and the second

was the Window technique.

First Group: In 33 cases, a flap was raised and the crown

of the unerupted canine was exposed and surgical osteotomy

was performed around the greatest circumference of the tooth

taking in consideration not to expose the amelo-cemental

junction. Bonding the orthodontic brackets was done during

surgery after drying the exposed tooth surface from blood asbest as possible.

The bracket was then bonded according to the accessibility

obtained. Before bonding the bracket, a ligature wire was tied

to it and twisted to form a long pig tail tie with an eyelet at its

free end [Fig. 5]. This extension was to dangle down into the

oral cavity through the flap that is replaced to cover the tooth

with its bracket bonded to its crown [Fig. 6]. By emeans of this

wire, the tooth was pulled to its destined position in the arch.

Second Group : This group comprised 33 patients. A

graduated periodontal probe was used to perforate the

anaesthetized oral mucosa to give a general idea as to the

position of the unerupted canine for determing the line of

incision. A semilunar incision was performed along the tip of

the located cusp and extended for 0.5 cm on both sides of the

tooth [Figs. 7a,b,c]. This was to allow viewing the position of

the embedded crown. The created flap was raised by blunt

dissection to expose the tooth around its great circumference

and to expose as much of the clinical crown as possible just

short of the amelo-cemental junction. Osseous surgery was

done with Ochschenbein chisels so as to avoid any heat

production from rotating instruments.



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SURGICAL AND ORTHODONTIC TREATMENT 93

Osseous surgery was done in a way that did not leave any

bulbous or bony projections that could hinder the path of

canine eruption. It should be noted that, approximately, 2 mm

of bone was left coronal to the amelo-cemental junction. This

would allow a proper co-aptation of the dentogingival

interface and secure a knife-like pattern of marginal gingiva.

The edges of the flap have been bluntly undermined and then


sutured all around the window with any soft tissue

immediately surrounding the crown. Periodontal pack wasapplied to burrow itself under and around the window and left

for one week [Figs. 7e,f,g]. At the time of bonding brackets

after one week, it was ascertained that the crown surface was

totally dry of any fluid.

To commence active orthodontic movement, a 0.018"x

0.022" rectangular stainless steel arch wire with a hellicle

between the lateral incisor and the tooth distal to the created

space, was ligated to the brackets. Teeth on either side of the

canine space were ligated together by stainless steel ligature

wire to secure anchorage and to prevent any loss of the

created space. By means of the elastic threads that were tied

to the hellicle in the arch wire and to the stainless steel

extension in the first method or the brackets in the second

method, gradual pulling forces were achieved until the canine

reached a convenient position. Once the crown was fully

exposed into the oral cavity, adjusting the position of the

brackets was done by rebonding. The time required to have

the impacted canine come actually into the oral cavity was

recorded for each case taking the time of commencement of

force applicatioon as a zero hour. Finally, the canine was

positioned in the dental arch by using 0.014", 0.016", 0.018"

and 0.018"x0.022" nickle titanium wires as deemed

necessary.

ResultsOf the 66 cases treated in this study, none came seeking

treatment for the impacted canine as all patients were not aware

of the presence of any abnormality. Accidental discovery of the

impaction was through routine screening in the Dental

Department.

Thirty-six (54.5%) cases had the canines bucally situated

while thirty (45.5%) were palatally impacted. Intraoral

examination revealed that 65 cases were unilaterally impacted

while bilateral impaction was present in only one case. Forty

cases (60.6%) showed retained deciduous canines. As a

prominent clinical finding, there was a bulge of the mucosa

either labial or palatal that determined the position of the


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impaction. Although this was not a common finding, it was,

more often than not, accurately determined radiographically. In

those cases which could not be detected by palpation or by the

presence of a bulge, lateral cephalometrics helped in locatingthe impacted canine [Fig. 1]. Intraoral occlusal films were

merely confirmatory to the cephalometrics.

Out of the 33 cases treated by the open-closed flap, 10 cases

showed loosening of the bonded brackets under the flap once,

while one case showed loosening of the bracket twice.

Re-entry surgeries were performed in those 11 cases to rebond

the brackets. A significant difference in the treatment time was

noticed in the bucally impacted canines compared to those

presenting palatally in both surgical procedures. The bucally

impacted canines reached occlusion at a faster rate than the

palatally presenting as indicated in Tables 1, 2, 3 and 4 treated

by either the Window or the Open-closed method.



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Table 1.Time required for maxillary impacted canines to reach occlusion (both bucally and palatally impacted) in the open-clos flap technique.

Buccally Impacted Palatally Impacted

No. of Cases Time to Reach Occlusion No. of Cases Time to Reach Occlusion

4

5

6

3

3 months4 months

5 months

6 months

5

4

5

1

8 months9 months

10 months

11 months

Table 2. Distribution of mean time to reach occlusion in months for

bucally and labially impacted canines in open-close flap technique.


Time (N = 8) (N = 15)

Range 3-6 months 8-11 months

Mean 4.4 9.1

S.D.

1.1

0.99

T = T= 12.78

SD = Standard DeviationP < 0.05 There is a significant difference

Tables 1- and 2 show that 18 cases of bucally impacted

maxillary canines reached occlusion during a period ranging

from 3-6 months with a mean time distribution of 4.4 months

+1.1. Fifteen palatally impacted cuspids reached occlusion

during a period of 8-11 months with a mean time distribution

of mean time of 9.1 months = 0.99. Both types of impactions

were surgically exposed by the open-closed flap techniques.

Tables 3 and 4 indicate that 18 cases of bucally impactedcuspids erupted and reached occlusion during a period of 3-5

months with a distribution mean time of 3.9 months with a SD

= +0.8 while 15 palatally impacted canines reached occlusion

within a period of 8-10 months with a SD = +0.63. Both types

Table 3.Time required for maxillary impacted canines to reach occlusion (both bucally and palatally impacted) in the window technique.


No. of Cases Time to Reach Occlusion No. of Cases Time to Reach Occlusion

7 3 months 7 8 months



Table 4. Distribution of mean time to reach occlusion in months for

bucally and labially impacted canines in the window technique.Table 5.Angles formed by the long axis of impacted canines and the

Frankfort horizontal plane.


Time (N = 8) (N = 15)

Range 3 - 5 months 8- 10 months

Mean 3.9 8.6

S.D. 0.8 0.63

T = T= 18.46

P < 0.05 There is a significant difference

of impactions were surgically exposed by the Window

technique.

Table 5 illustrates the effect of angulation of the long axis of

palatally impacted canines with Frankfort horizontal plane on

the time taken by the impacted canine to arrive to occlusion. It

was shown that the more acute the angle was, the faster the

impacted canine reached occlusion and the more obtuse the

angle was, the longer the period taken by the impacted canine

to reach occlusion. Thus, as depicted from this table, for 12

cases with an angle ranging from 95 to 110, the time of

No. of Cases Range of Angle Treatment Time

12 95- 110 8 months

11 110- 120 9 months

7 120- 135 10 months

treatment was 8 months. In 11 cases with angles ranging

between 110 and 120, the teeth reached occlusion in nine

months of treatment.

Seven cases with angles ranging from 120 to 135 reached

occlusion after 10 months irrespective of the surgical technique

used to expose them. It was also found that four of the cases

treated by the Window technique showed active tooth eruption

without any ortho-mechanics applied.

Discussion

Impaction of the maxillary canine is a problem frequently

encountered in orthodontic practice. The complexity of

diagnosis and treatment plan using taxes the orthodntist's and



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SURGICALAND ORTHODONTICTREATMENT 97

surgeon's intelligence. Indeed, there are several modalities in

treating impacted maxillary canines dictated by several

parameters.

The results obtained from this study showed that labial

maxillary canine impaction is more common than palatalimpaction. This does not coincides with the findings of

Fergusson3

who concluded that displacement from normal path

of eruption most commonly occurs in a palatal direction. Also,

Orton et al8

asserted that most ectopic canines are palatally

impacted. On the other hand, Richardson and McKay4

questioned the validity of this concept as applied to many

maxillary displaced canines. Although heredity has been

implicated as a cause in maxillary canine impaction4

yet, in the

present study, no familial background has been detected.

Fearne et al9

correlated impaction of maxillary canine and

cystic formation around the unerupted canine.

In the cases presented in this report, only one patient

exhibited a cystic formation around an impacted canine.

Anterior segment crowding has been considered as a cause in

maxillary canine impaction3

yet some cases presented in this

report showed the presence of enough spaces to accommodate

normal eruption of the impacted tooth to its destined position.

The available spaces resulted from the presence of peg-shaped

laterals, congenitally missing laterals and retained deciduous

canines. In this respect, crowding could not be a major factor in

maxillary canine impaction. This is in agreement with the

findings of Moss2, Brin et al

10and Jacoby"

Surgical management of impacted canine for orthodontic

mechanics has been a subject of controversy. The Window

technique, performed by several authors,3'6 did not gain

acceptance. Opponents to this technique advocated that

removal of a tissue from an impacted canine might result in a

"pathological" dento-gingival junction of the finally erupted

tooth.2'12

Proponents of the open-closed technique concluded

that the risk of attachment loss is reduced if a flap is raised

and then replaced over the exposed crown of the impacted

canine after attaching a suitable means with which traction of

the impacted canine is applied.1213

In this study, the Window

technique gave better clinical results when compared to the

open-closed technique for several reasons. It was found

indeed that such a procedure is more convenient to the

surgeon, the orthodontist as well as to the patient himself.Bonding of the impacted exposed canine could be easily

performed in "open air" after controlling the fluid

contamination of the tooth surface if it is bonded during

surgery. Another advantage of the Window technique is that it

enables the orthodontist to observe all professional tooth

movements during the treatment period, rather than moving

the hidden canine under a flap which is indeed unpredictable.

A second and, at times, a third surgical re-entry procedure

should be performed to re-bond a loose bracket, which in

itself is traumatic both to the patient and the gingival tissues.

It should be added in this respect that the Window technique

allowed the impacted canine to reach its destined position at a

faster rate than impacted canines exposed by the open-closed

technique. The suturing procedure adopted in the Window

technique allowed the soft tissues to heal in a knife-like edge

with the tooth surface resulting in proper co-aptation of the

marginal gingiva of the finally erupted tooth. The extrusion ofa peg-tail extention from under the raised flap in the

open-closed technique method was reported by several

patients in this study to be very irritating.

Finally, the angle existing between the long axis of the

impacted canine and Frankfort horizontal plane could affect the

period taken by the impacted maxillary canine to reach

occlusion irrespective of the technique performed to expose it.

In this report, it was found that the most favorable angle is

from 95 to 100 degrees.

Conclusion

Based on the results of this study, the following conclusions

are drawn :

1. The devious path and the late development of themaxillary canine seemed to be the most acceptable cause

of its impaction.

2. Impaction of the maxillary canine was found to be morecommon buccally than palatally.

3. A significant difference was found between bucally andpalatally impacted maxillary canines in terms of

treatment time. Bucally impacted canines reached

occlusion faster than palatally impacted canines.

4. The impactions reported in this study were discoveredaccidentally in patients who came for other dental

consultations.

5. The angulation of the palatally impacted canine inrelation to Frankfort horizontal plane had a direct effect

on the period of treatment taken by the orthodontically

moving canine to reach occlusion.

6. Comparing the two surgical techniques of exposing theimpacted maxillary canine, the Window technique was

more advantageous than the Open-closed flap technique

in our hands and more promising in bringing the tooth

into occlusion.

7. Greater number of cases should be treated by the Window technique in future studies to validate our

conclusion that the Window technique was superior tothe Open-closed flap technique.

References

1. Bass TP. Observation on the misplaced upper canine. DentPract Dent Rec 1976;18:25-33.

2. Moss JP. The unerupted canine. Dent Pract Dent Rec1972;22:241-48.

3. Fergusson JW. Management of unerupted maxillary canine.Br Dent J 1990;169:11-17.

4. Richardson A., McKay C. Delayed eruption of maxillarycanine teeth. Part II. Treatment. Proc Br Pedodont Soc

1983;13:13-23.



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98 MARZOUKET AL

5. Bishara SE. Impacted maxillary canine: A review. Am JOrthod Dentofac Orthop 1992;84:159-71.

6. Hunter SB. Treatment of the unerupted maxillary canine.Preliminary consideration and surgical methods. Br Dent J

1983;154:294-96.

7. Dewel BF. The upper cuspid. Its development and impaction.Angle Orthodont 1949;19:79-90.

8. Orton HS, Gravey MT, Pearson MH. Extrusion of the ectopicmaxillary canine using a lower removable appliance. Am J

Orthod Dentofac Orthop 1995;107:349-59.

9. Fearne J, Lee RT. Favorable spontaneous eruption ofseverely displaced maxillary canines with associated

follicular disturbance. Br J Orthodont 1988; 15: 93.98.

10. Brim I, Becker A, Shalhay M. Position of the maxillar

y permanent canine in relation to anomalies or missing lateral

incisor. A population study. Eur J Orthod 1986;8:245-55.

11. Jacoby H. The etiology of maxillary canine impaction. Am JOrthod Dentofac Orthop 1938;84:125-32.

12. Wisth PJ, Nodeval K, Boe OE. Comparison of two surgicalmethods in combined surgical orthodontic correction of

impacted maxillary canines. Acta Odontol Scan

1976;34:53-57.

13. Wong-Lee TK, Wong FCK. Maintaining an ideal toothgingiva relationship when eexposing and aligning an

impacted tooth. Br J Orthod 1985;12:189-92.

14. Isiekwe MC, Nwoku AL. Surgery as an adjunct in theorthodontic management of impacted maxillary canine.

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Combined Surgical and Orthodontic Treatment of Impacted Maxillary Canines

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