The surgical uncovering and orthodontic positioning of unerupted maxillary canines Karl von der Heydt, Glen Ellyn, Ill.

T

D.D.S.,

M.S.D.

he incidence of unerupted maxillary canines is such that the correction of this condition represents a significant portion of many orthodontic practices. Appropriate surgical uncovering of these teeth by a competent oral surgeon is one of the finest services that can be offered to the orthodontic patient. The skill of the oral surgeon spells the difference between an easy-to-solve orthodontic problem and a frustrating experience for both patient and orthodontist. The surgical technique involves exposure of the crown of the tooth by removal of overlying bone and gingival tissue and packing with two different materials. The first pack is to stimulate movement of the tooth toward the oral cavity, and the second pack is to maintain the opening through the gingival tissue. A tooth can be stimulated to erupt into the oral cavity in a vital condition if the follicular space is tightly packed on one side with baseplate gutta-percha. Softened gutta-percha pieces are forced into the space between the tooth and the bone surrounding it. The tooth will migrate away from the site of pressure. The wound is packed open with surgical cement to prevent the closing of the area by healing. Generally, these packs are allowed to remain until they fall out. Repacking is done with both materials as often as is necessary to make the tooth suitable for the placing of a preformed band or the application of a bonded attachment. The use of preformed bands has made this a routine orthodontic procedure. It is, indeed, surprising how often a badly displaced tooth can be ideally banded with appropriate attachments which can be used for completion of treatment. When this technique is used, there is no need to make a casting for the exposed portion of the tooth, no need to make a clumsy ligature lasso, and no excuse to drill a hole for insertion of a pin attachment. An experienced oral surgeon can 256

estimate the bandability of his surgically moving tooth and will continue his packing procedure until the orthodontist will be able to place a band with ease. The practice of bonding attachments directly to the enamel surface of teeth has not lessened the necessity for excellent surgical skills. Well-exposed surfaces are more critical for successful bonding than for the application of a preformed band which can be introduced without discomfort below the surface of the gingiva. The

maxillary

canine

Canine teeth are vital to the continuity of the dental arch. They are found at the angle of the mouth, occupying a critical position in the arch at the junction between the anterior and posterior teeth. Canines offer two faces-one which is continuous with the incisors and a second which is aligned with the posterior teeth. In addition to its two faces, it has two cutting edges-one to the mesial and one to the distal. In unworn teeth, an angle of 901 degrees is created by the union of these cutting edges forming the single cusp for which the tooth is named ‘(cuspid.” The canine is a large, strong tooth of simple design which has a far longer root than any other tooth in the human dentition. In the pattern of eruption, the canine is scheduled to erupt late, long after its mesial neighbor, the lateral incisor, and definitely after its distal neighbor, the first premolar. Because the total arch length for the permanent teeth is primarily established very early in life, at the time of eruption of the first permanent molars, and because the canine is big and late in erupting, it is often not found in the alignment of the arch. As in musical chairs, the room for this late and prodigious tooth is all gone, and it must assume an awkward and embarrassingly inappropriate position out of the arch alignment. Canines are commonly referred to as “impacted,” a convenient but technically inappropriate description. “Unerupted” would be a better term. Maxillary canines arc found beneath the gingival tissue beyond the arch form of the other teeth, “unerupted” to the lingual or labial. Lingually impacted teeth appear much less accessible to the oral cavity than they are. The depth and curvature of the palate make palatally impacted teeth closer to the surface than they might appear in a radiograph. The exposure, packing, and positioning of lingually impacted teeth can create quite a spectacular orthodontic result with a rather routine and uneventful orthodontic effort. A buccally displaced tooth is in a relatively inaccessible place. The refraction of the labial tissue may inhibit exposure of this tooth, to the complete satisfaction of the surgeon and the orthodontist. The tissue tends to be less keratinized, and it is difficult to maintain a clean and healthy environment. The buecal plate allows little tolerance, which causes the teeth adjacent to the impacted canine to be displaced also,. Because there is much less maneuvering room between the buccal plate and the roots of the adjacent teeth on this side of the arch, extra

care must be taken to move teeth ill :111appropri;~t(~ ilircctioll sequence of movements must bc followc~cl Clinical

+III~I ~II (trcltkrl\

material

In addit,ion to a short description of the surgical method of preference, six different clinical cases have been selected for discussion. E:ach of these eases has some interesting clinical feature which will be expanded. The first case (Fig. 2) was selected to demonstrate the positioning of a maxillary canine into the maxillary arch continuity prior to the removal of four first premolars. This was followed bF typical Begg treatment. In the next case (Fig. 3), it was possible to follow the steps in a surgical uncovering of a buccally displaced maxillary canine. When this tooth became bandable, the progress was followed as this tooth moved toward an appropriate berth in the maxillary arch form. This is a nonextraction case. The position of both palatally unerupted maxi1lar.v canines was close to the midline of the palate in this case (F’ig. 4). Because this was a nonextraction situation, it was desirable to bring both these teeth into the continuity of the maxillary arch. This is the only case selected which is under treatment as this article goes to press, but it offers an opportunity to demonstrate some mechanical devices that, were not available in some of the older examples. A combination of buccally and lingually unerupted canines in one case is a unique situation. This combination is found in Case 4 (Fig. 5). The early removal of four first premolars forced the orthodontic movement of these teeth into the arch continuity. The contrast in difficulty in attaining an appropriate alignment of the canines between tho buccally and palatally unerupted teeth is apparent in this case. The last maxillary canine case selected demonstrates a combination of actions (Fig. 6). The palatally displaced maxillary canine was brought through the occlusion while the Class 11 molar relation, deep overbite, and incisor protrusion were being corrected. This is also the case which has been out of t,reatrnent the longest. The final clinical example is that of a maxillary left incisor which was unerupted in the early mixed dentition (Fig. 7). The same surgical procedure was used, and the case was followed until the early adult dentition was present. Surgical

technique

The surgical uncovering of the unerupted maxillary canine has been the responsibility of the oral surgeon. It is he who designs a flap, retracts it, and trims the tissue in an appropriate manner. He also chisels the bone to form a channel through which the crown can pass. Once the window is prepared and the coronal sac is removed to gain access to the crown of the canine, the packing process can be instigated. Appropriate radiographs have established the position of the canine in this case. It is under a prominence which can be seen in the palate as a lump to the lingual of the left central and lateral incisors (Fig. 1, a). Adequate surgical exposure of the crown of the canine has been made. The

Volume Number

68 3

Unerupted

maxillary

canines

259

Fig. 1. A and 8, Surgical exposure of unerupted lingually-displaced canine in preparation for orthodontic placement of this tooth. C, Packing with gutta-percha to stimulate eruption and movement toward the oral cavity. D, Surgical WondrPak dressing. E, Repacking with surgical WondrPak. Locking material around remaining teeth. F, Canine available for placement Starschak,

of orthodontic Aurora, Illinois.)

band.

(Courtesy

of

Dr.

Howard

Gillette

and

Dr.

Thomas

overlying tissue has been neatly trimmed away (Fig. 1, B) . The crown of the tooth is accessible, and the follicular space can now be packed. Softened baseplate gutta-percha is introduced between the labial surface of the crown and the socket and is wedged into the follicular space (Fig. 1, C). This will force the crown to move away from the proximity of the left central

Fig. 2. A, Radiograph left canine canine for

exposed movement

Begg

1 arch

Stage

of lingually displaced canine. Deciduous and available for orthodontic treatment. of this tooth prior to removal of four

canine retained. C, Application first premolars.

8, Upper of force to D, Typical

wires.

and lateral incisors and will cause the tooth to erupt toward the oral cavity. In order to keep the crown open t.o the oral cavity, a packing of surgical WondrPak has been placed over the crown of the canine (Fig. 1, D) . The patient was dismissed at this time. The process of packing and wedging into the follicular spare with heated and softened baseplate gutta-percha may bc rcpcated seTera times at subsequent visits (as in Fig. I, C’), and the wound may be packed open again with WondrPak (Fig. 1, E). Any mechanical lock can be used. An example is the locking of t,he WondrPak between the left lateral incisor and first premolar. These two packs are allowed to remain in place until they fall out, and they are replaced as often as necessary to produce a bandablc tooth (Fig. 1, 3’). Preformed bands will slip over and on teeth which appear to be much too short in the crown. It. is also possible to have brackets and attachments slip into the area which may have been occupied by the baseplate gutta-percha wedge. The cleanliness of the tooth and the healthy condition of the surrounding gingival tissue make for successful cement,ation of the band. There is considerable advantage to having the opposite tooth of the pair of upper ca.nines to establish an appropriate-sized prefabricated band for its mate.

Fig. 2 (Cont’d). and elastics. removal.

E, Typical Stage 2 arch wires and elastics. G, Overtreatment of closed bite. H, Setting

F, Stage 3 arch wires, of teeth 18 months after

auxiliaries, appliance

Case 1 The first requirement in diagnosing a case in which a tooth is displaced is to establish the feasibility of bringing the tooth into the oral cavity in such a way as to make it useful to the patient. A radiograph sholved the presence of a palatally displaced upper left canine (Fig. 2, A). The root of the deciduous canine had been extensively resorbed. Waiting for spontaneous eruption of the canine would have been futile. An oral surgeon performetl the surgical procedure just described (Fig. 1, -4 to F), and the patient returned for the orthodontic procedures which would place this tooth in an appropriate position. The tooth was found to he readily bandable (Fig. 2, R), and the arch was photographed with the use of a metal mirror. Upper and lower hands have been placed on the six anterior teeth and four first molars. The first attempt was to position the upper left permanent canine in the arch. This was done easily through the application of elastic thread. Since the appropriate position of the upper left canine had been attained, the case was now diagnosed as one which required the removal of four first premolars. Twatment \vas then undertaken with typical Regg appliances and was (BarrA out as though the canine had never been in the palate. Begg Stage 1. Wires lvere placed after 10 months of pre-Stage 1 treatment (Fig. 2, D). The four first premolars Tvere removed. A multiple-loop arch was constructed for the lower arch and was pinned to position. Class II intermaxillary elastics were Jrorn. Stage 2 was undertaken I month later when the premolar spaces were being closed with tied elastic thread (Fig. 2, B). The wearing of Class 1I elastics was also continued during the first part of Stage 2. This required 6 months of treatment. Seven months was consumed in attaining the goals of Stage 2. When the incisors \vere retracted to an edgr-to-edge> relationship (Fig. 2, F), the arch wires n-rrc replaced with

Fig.

3.

a,

Labially

displaced

dressing

in

place.

B,

position

to

move

canine

percha and

wedge. away

reaction intervals.

from which Surgical

D, Six the will

upper

Four

weeks away

weeks lateral move

dressings

left

canine

later, from

later,

the the

incisor canine replaced

the as

exposure

has

lateral

canine

root. to

after

dressing

been

incisor has

E, A distal.

been

second F,

by

root.

Repacking

Another to

to

surgeon.

Surgical

Gutta-percha

C,

repacked angle

oral

lost.

show has

wedge view

move

it both

packing continued

of and at

in

guttadistally tissue &week

necessary.

0.018 inch base arch wires and appropriate auxiliaries: root-paralleling springs 011 the mantfil)ular and maxillary IRteriti incisors, canines, and premolars and a prefxhricnte~l tlvo-fingeretl torquiny wire on the maxillary wntral incisors. All bands and wires were removed when the roots had been paralleled at the extraction sites, the incisors overtorqued, and thy bite oprnwl. A positioning appliance was constructed and worn for 6 months (Fig. 2, E). The teeth settled into appropriate positions and, 2 years later, have maintained their positions as established.

Unerupted

maxillary

canines

263

Fig. 3 (Co&d). G, After 6 months the canine has been forced distally and separated from the lateral incisor. H, Eight weeks after exposure the canine was bandable. I, Full Begg appliances placed 8 days later. Elastic tie to move canine distally from helix in loop. J, Elastic tie replaced in 1 week to a different loop in original arch wire. K, After 5 months, a simple 0.016 inch arch wire replaced the original arch wire with the loop. The canine has been engaged in the bracket slot. 1, Three weeks later an auxiliary to torque the lateral incisor was added from central incisor pin slot to canine pin slot.

Once extraction Case

the canine problem.

had

been

brought

into

the

arch,

this

case

became

a typical

four-premolar-

2

Ruccally displaced canines have offered more of a challenge than teeth lingually unerupted. Quarters are much closer on the buccal than on the lingual side. There is no structure analogous to the buccal plate on the lingual side. The presence of a buccal plate tends to crowd the buceallg unerupted tooth into its neighbors. These neighboring teeth are forced

Fig. 3 (Cont’d). M, A more elaborate reverse torquing auxiliary was constructed, also originating in the central and canine bracket slots but having a finger which was pinned into the lateral incisor bracket under the main arch wire. N, The effect on the tooth can be observed and the action of the wire noted. 0, All active appliance wire removed and a positioning appliance constructed. P, Seven months later the teeth have settled well and the spaces closed.

surgical exposure ran be limited to compensate and are often severely displaced. In addition, by refraction of the labial tissue. This is lrs~ keratinized, more sensitive, anti not selfcleansing. An opportunity to photograph the progress of a buccally displaced upper left canine presented itself in this case. The effect of gutta-percha packing can be followed in thr series of photographs. The movement of this tooth into position was begun in the mixed dentition. The CIIW had been diagnosed as a nonextrartion malocclusion in which the upper left canine was necessary for arch continuity. The deciduous canine had an almost fully formed root. It \vas removed to make room for the pcrmantnt canine. The buccally displaced upper Ioft canine was exposed by the oral surgeon, packed with gutta-percha, and covered with WondrPak. The patient returned to the orthodontist with the tooth covered with WondrPak and jvas photographed (Fig. 3, A J. About 3 weeks later the WondrPxk had fallen away, exposing gutta-perrha both to the mesial and under the distal corner of the canine. The photographs shown in Fig. 3, H and (J were taken at this time. This sl~ows the packing from two angles. Thea packs wre placed to move the tooth both distally and bucc~~lly toward the oral cavity. Six weeks later the buceal surface of the canine had emerged considerably (Fig. 3, II). There was now a different gutta-percha packing on the mesial side of the tooth and also orw on the mesial-incisal corner (Fig. 3, h’, taken the same time as Fig. 3, D). A small area of proud flesh was seen between the Tao packings on the mesial surface. These would move the tooth in the desired direction, which man to the distal and buccnl. Swwal intermediate pack-

VoZume Number

68 3

Unerupted

maxillary

cawines

265

ings new Fig.

were made, but not photographed, and 5 months later the patient returned with a packing of both gutta-percha and WondrPak. The generous WondrPak is visible in 3, F. The packing was removed by the orthodontist at this time, and photographs were made of the exposed canine (Fig. 3, G) . The time for banding was approaching. and 2 months later the tooth had become One more series of packings was made, bandable (Fig. 3, H). A small corner of the gutta-percha was visible to the mesial of the tooth. This was removed, and a preformed band was placed. In addition to the canine, which had been the center of attention from November through August, the remaining anterior teeth and all four first molars were banded. Also during this time the remaining deciduous teeth had been spontaneously shed and the permanent teeth were erupting (Fig. 3, I, taken on the same day as Fig. 3, IT). Full-banded appliances of the Begg type were placed. They were made of 0.016 inch Australian wire with vertical loops in the upper arch wire. A helix was constructed in the most distal vertical loop and an elastic thread attached this loop to the canine bracket. A week later (Fig. 3, J) a different elastic tie was made to a different circle 100~ previously bent into the arch wire, and changes were made with this same arch wire for the next 5 months. A simple 0.016 inch Australian arch wire was placed at this time, and it was possible to engage and pin the brackets of all the upper anterior teeth (Fig. 3, 9). Three weeks later the first attempt was made to apply buccal root torque to the left lateral incisor, the root of which had been forced into a lingual position by the canine. This torquing device (Fig. 3, L) was nothing more elaborate than a 0.012 inch trapeze-shaped wire the sides of which were inserted into the pin channel of the central incisor and canine. The bar of the trapeze produced pressure in the desired direction on the incisal portion of the lateral incisor. The amount of labial root torque required for lateral incisors in some bucally displaced canine cases and in some lingually displaced canine cases has led to considerable experimentation with “reverse” torquing springs. Fig. 3, M shows such a device on the upper left lateral incisor. It is constructed of 0.014 inch wire, containing a loop which is placed in the bracket before the main arch wire and pinned together with the main arch wire to the lateral incisor. The ends of the arch wire are inserted into the pin channels of the bracket and bent over like pins to the gingival of both the central incisor and canine brackets. Pressure is placed on the lateral incisor through the vertical portion of the loop on bot,h sides of the lateral incisor bracket. This is an effective “reverse” torquing auxiliary. Six weeks later the auxiliary spring had torqued the lateral incisor in the desired direction (Fig. 3, N). There had been some reaction to the canine, and the change in shape of the auxiliary spring can be seen. A bettter auxiliary is now available (Fig. 4, Q to P) , Some 7 months after placement of the simple arch all appliances were removed and a tooth positioner was placed. After 7 months with the positioner, the teeth had settled well (Fig. 3, P). This has continued to improvr. Case

3

It was decided that a full complement of teeth was necessary for facial esthetics, dental balance, and stability in this case. For this reason, the very badly displaced upper canines were uncovered and orthoctontic treatment was undertaken (Fig. 4, A). The oral surgeon was able to expose both teeth very nicely. It was also possible to place well-fitting preformed bands in a surprisingly good position, OS they have not had to be replaced as the treatment proceeded. Until it was decided that the misplaced canines were both exposahle and bandablr, the deciduous canines were left in place (Fig. 4, B). Bands were placed on both canines with typical Regg brackets. In addition, there were eyelets on the distolingual corner. The upper incisors, first premolars, and first molars were also banded, and a simple arch wire was placed. A free-tied elastic was plncc~l between the eyelets on the canine bands and hooks, which were on the lingual asp& of the upper first molar bands. The teeth responded by turning and moving distally.

Fig.

4.

A,

Radiograph

Photograph canine arch. bracket. buccally.

in bands

C,

Five D,

showing

mirror. to

weeks Elastic

F, Canines

Free

lingual later, thread about

proximity elastic

hook steel ties to

on

of

thread first

molar

ligature replace enter

right

ties steel

space

and

tied

from bands.

to

loop

ligature. in arch.

left

canines

eyelet Both hook

to

on

palatal

distolingual

deciduous on

E, Canines

main have

canines arch

wire

turned

suture.

6,

aspect

of

remain from and

in Begg

moved

Unerupted

Fig.

4 (Cont’d).

buccal

the arch

vices engaging lower the

H, Six months after canines were first banded they are visible from J, The right canine has crossed the occlusion and the left is trapped K and 1, The right canine has been engaged on canine 9 months later.

lower the

been the

left left

first

upper

267

I and

wire;

have

canines

G and

aspect.

behind the

ma,xillary

left

lateral

added

right

to

canine.

premolar canine

to

incisor both

The

and

these left

has

been

pass

it.

canine

M

teeth.

canine removed

has from

roots and been the

are N,

tied bracket

crossed.

Labial to

Root-paralleling

root-torquing

loop slot

on to

the depress

de-

fingers upper

arch.

it and

are The allow

Fig. to

4 (Cont’d). engage

was

constructed

root

torque

dissipated right

are

a

in

in assuming press.

left

and the

placed

canine

crossed more

Five has

root-torquing

canines. with

canines.

is little

gently.

V, The

P, Labial

and

and

to

T, There

5 and

to

0

right

weeks

appropriate

a

of

and

pair auxiliaries

reaction have

made

attitude

R, After

These

adverse

fingers

Q and

to

elapsed

excellent

were

the The

last

left

lateral have

is under

been treatment

main

arch

wire

plain

arch

wire

of as

pairs

the inch which

made

auxiliaries

springs case

into 0.018

auxiliaries factory

piggyback

progress. This

bent an

piggyback

between

root-paralleling positions.

were

3 months,

deliver

labial

high-tensile

the

reverse

of

photographs.

incisor

and

added as

to this

wire. torque

is

U and canine

roots

assist

them

article

goes

Unerupted

maxillary

ca&nes

269

Two months later both deciduous upper canines had been removed and the main arch mire had been replaced. A photograph, taken with a mirror (Fig. 4, C), showed that there had been a steel ligature threaded into the pin channel of the Begg brackets on both canines which were then tied to the circles which were incorporated into the arch wire. The distortion of the arch wire showed that force was hring applied to these teeth. Two months later, as the teeth responded to this force, the steel ties were formed into loops through which elastic thread was passed and tied once more to the circles on the main arch wire (Fig. 4, D). These elastic ties were replaced at 6.week intervals and rephotographed 3 months later (Fig. 4, E). The teeth were turning and moving toward the space previously occupied by the deciduous canines. As the teeth moved, the length of the elastic has diminished and steel ties have been substituted. This can be observed from three different angles, all taken at the same appointment (Fig. 4, F, G, and H). Fig. 4, P shows the last of the series of occlusal views taken in a mirror and the photographs in Fig. 4, G and H are the first of the se&es which show right and left taken at the same appointment. The remaining photographs in FEg. 4 show right and left pairs. The relative positions of the upper left and right lateral incisors should be noted in Fig. 4, G and H. The upper right canine moved through the occlusion rather easily (Fig. 4, J), but the upper left canine ran into interference (Fig. 4, J). A vertical loop was incorporated into the arch to assist the tooth into position. Four months later the upper right canine had been attached to the main arch wire through the usual bracket slot (Fig. 4, 9). The left canine was not responding as well (Fig. 4, L). A reverse root-paralleling spring had been applied to the upper left lateral to reduce the root interference with the canines. A paralleling spring had also been placed on the left canine to move its root distally and free it from the lateral root. This canine spring was more difficult to see. It ran through the pin slot on the bracket and was bent over on the incisal end. It extended through the tie on the left first premolar and was inserted into the buccal tube on the molar band. This end of the wire was beyond the edge of the photograph. The springs were removed and a new arch wire was constructed. This included a pair of finger springs straddling the bracket on the upper right canine. These fingers were positioned to produce buccal root t,orque on the right canine (Fig. 4, M). On the opposite side, vertical loops had been incorporated for engagement of the left canine. The root positions of the lateral and canine had been improved. Finally, the upper left canine had been brought to the correct side of the occlusion, assuming a position similar to that of its mate 14 months earlier. This difference in difficulty was not apparent when the two incisors were first exposed. Now right and left canines had buccal root torque applied in a similar manner (Fig. 4, P and Q). The main arch mire had fingers incorporated in it in such a way that they straddled the canine brackets. The incisal end of the fingers applied buccal root torque to both teeth. A little extra support was gained by allowing the lock pins to extend over the torquing fingers. At this time in treatment a new design of preformed auxiliary “reverse” torquing wire became available, and one was placed on each canine (Fig. 4, Q and R). There are many advantages in using “piggyback” \riws of this nature; the most important advantage is the siphoning off of the reciprocal forces. When appropriate base arches are in position, no compensatory arch wire manipulations are necessary. These auxiliary wires are constructed to straddle the bracket with a finger extending incisally down both sides of the brackrt. The center of the “W” fits in the bottom of the bracket slot. After the center of this auxiliary is first placed into the arch wire slot in the hraeket, it is activated by raising the mesial and distal legs of the wire. These are placed into the brackets on several teeth on each side of the tooth to be torqued. The main arch wire is placed second into the bracket and shares the slot on the bracket with the auxiliary. They are pinned into the slot together. This relation is the reverse of the order followed in applying auxiliaries whicah deliver lingual root torque to thr teeth.

Fig.

5.

A,

Close-up C,

D,

Mirror of

and

upper E,

First

canines

have

been

eventful

positioning

photograph anterior arch

wire

banded of

of teeth

upper

upper illustrates

shows and right

front,

attached

arch

reveals

upper left, with

left and elastic

upper

:ight

canine

with

right thread

views

canine of

to

in

palate.

gutta-percha main

anterior arch

B,

packing. teeth. wire.

Both F, Un-

canine.

Five weeks later thesr: two auxiliaries had llegun to exhibit their S and 2’). The canine roots had moved bucally, and the tip of the wsp position. As the root of the right canine assumed a better position, the tip improved (Fig. 4, U). This action was produced, in 3 months. The left more problems than tlrcl right one (Fig. 4. T). Because the left lateral distally and the left canine root WCS displawtl mesially, root-pamlleling to both teeth. The additional springs will uncross these roots, allowing assume an appropriate position in the alveolar bone.

effectiveness had assumed

(Fig. 4, a better

of the cusp had also canine again offered root was displaced springs were applied the canine root to

Fig. 5 (Cont’d). G, Steel ligature tie of canine to move distally. H, t/s inch elastic on arch and attached to bracket of canine. I, Poor position of upper left lateral J, Reverse finger springs on left lateral incisor to produce labial root torque. root-torquing auxiliary on left lateral incisor. Canine assuming better position. 1, of lateral incisor successful. Space-closing arch wire. M and N, Occlusion on left at time of appliance removal.

threaded incisor. K, Labial Torquing and right

Case 4 It is most unusual to find a bucally dixl)lacrd and a lingually displaced pair of upper canines in the same mouth. In the next case, thus upper right vaninr was to tlrta lingual (Fig. 5, A ) and the upper left canine was t,o the buc~tl (Fig. 5, 11). These were exposed by the oral surgeon aud thr I~uc~ally displaced eaninta xxs packed with baseplate gutta-prreha (Fig. 5, A and Ii ). The four first premolars had been removed several years before, and the spaces wercb virtually closed in thrs lower arch and overclosed in the upper. Fig. 5, C, E’ shows photographs of the full Regg appliance used t,o begin treatment. Fig. 5, C shows the anterior teeth banded and t,hr arch wire placed. The bucallp displaced The left, lateral incisor was not left canine has been banded. This presented some problems. engaged on the arch wire because the lateral incisor should not IW moved toward the high canine. For distal movement, the left canine was tied with elastic thread from the bracket to the main arch wire which contained a vertical loop with a circular top (Fig. 5, n). Elastic thread also tied the right canine to the main arch wire through the spxces available. The lingually placed right canine assumed an appropriate position uneventfully. Fig. 5, P shows the tooth 18 months later. Intermediate photographs were of little interest. The upper left buccally displaced canine offered a considerably greater challenge. The photograph shown in Fig. 5, G was made 2 months after the first appliance \vas placed. The tooth had made some considerable progress toward the distal. To prevent damage to its the Icft lateral was not engaged on the arch wire. root by encroachment on the canine, The canine was tied to the circular loop in the vertical loop with steel ligature. and the arch wire mas bent around the distal aspect of thra molar tube. After 3 months (Fig. 5, R), the arch wire was replaced with one of a simpler design and the left second premolar was banded. The second premolar was being rotated tith an elastic tie from the lingual toward the distal to make more room for the canine. A small ligature elastic, $8 inch in diameter, was stretched from the arch wire to the bracket on the canine to move it toward the arch wire. Fig. 5, I shows that buecal root torque is needed to correct the lingually placed root of the upper left lateral incisor. An attempt was made to correct this problem by means of an arch wire with straddling finger springs to the bracket on the left lateral incisor (Fig. 5, J). This jras replaced with a plain arch wire with the previously described auxiliary, and the tooth ultimately assumed a better position (Fig. 5, X1. A space-closing and finishing arch wire was placed 4 months later. Roth lateral incisor and canine had assumed better positions (Fig. 5, L) . Three months later all band and wire appliances were removed and an Ortho-tain prefabricated positioner was inserted. The teeth are settling into arceptable positions and will continue to migrate toward a balanred and useful occlusion.

Case 5 The simultaneous action of a variety of orthodontic procedures is possible. This case was selected because several different tooth movrments were undertaken at the same time. In addition, 5 years have elapsed since the appliances were removed. The upper right canine was well exposed and erupted into the palate opposite an adequate space between upper right lateral incisor and premolar (Fig. 6, A). A solid Classs II molar relation and a deep overbitca and considerable ovc,rjet in the anterior teeth can be SHW in Fig. 6, H. Upper and lower 0.016 inch arch wires were constructed with appropriate anchorage bends anterior to the molar tubes. A pair of loops was incorporated to permit attachment to thcl lingually locked right canine. Class II intermaxillary elastics were worn from the beginning of treatment. During the first 3 months of treatment, thr bite opened, the molar relation improved, the overjet was reduced, and the lingually locked canine began to emerge through thcl

Unempted

Fig. 6. A, Occlusal extraction treatment, progress with bite

view of maxillary bringing upper opening, correction

ma,xillary

canines

273

cast reveals canine well exposed in palate. B, Nonright canine into arch with loop arch. C, Simultaneous of Class II molar relation, and positioning of canine

in 3 months. D, Eight months later, canine has been aligned; Class II correction and improvements in molar relation continue. E, Overcorrections for deep overbite at time of band and wire appliance removal. F, Five years later, a stable occlusion is apparent.

occlusion simultaneously (Fig. 6, C). At this time a new upper arch wire was constructed and Class II elastic traction was continued. Another pair of arch wires were formed after 8 more months (Fig. 6, D). To allow for free interplay of the action of the arch wires from posterior to anterior, which is necessary, the lower premolars and the upper right second premolar were not banded. The Class II intermaxillary elastics were continued until all bands and wires were removed (Fig. 6, E). The deep overbite was overtreated, and the upper molar tipped distally. Fig. 6, F shows that, free of all retention 5 years later, the teeth have settled into satisfactory interdigitation with appropriate overbite and overjet.

Fig. 7. A, Upper left central incisor exposed and packed by oral surgeon. B, Bands are placed on upper molars and three incisors. Compressed coil spring activated to gently open space for central incisor. C, Spontaneous eruption of central incisor. D, Band added to left central incisor. Sectional 0.016 inch arch wire placed. E, All bands and wires removed. F, Fourteen months later, teeth are assuming positions appropriate for patient’s age. Case

6

This early-mixed-dentition case offers Any tooth can be uncovered with this technique. a different kind of problem. The upper left central inciser had been prevented from erupting into the arch. It was exposed and packed by the oral surgeon (Fig. 7, a). The surgeon had made the upper left central incisor accessible to the oral cavity. Orthodontic bands were placed on the upper lateral incisors, right central incisor, and first permanent molars. A simple arch wire was placed with a compressed coil spring between the right central and left lateral incisors (Fig. 7, B). No effort was made to make an attachment to the left central incisor, but it had been appropriately packed by the oral surgeon.

As the space opened, the left central incisor spontaneously migrated toward the opening area (Fig. 7, C). The space was opened slowly and carefully because of the nearness of the lateral incisor roots to the uneruptrd canine crows. The upper left central incisor became easy to band. A small sectional arch was placed from lateral incisor to lateral incisor (Fig. 7, n), which allowed the lateral incisors to move distally as the central incisor drifted into position. During the next 9 months, the \vire portion of the appliance was removed several times. Each time the central incisor moved back toward its original position. Finally, the central incisor did remain in position and the llands were then removed (Fig. 7, E). After 14 months the gingival tissue had improved, t,lre deciduous teeth had been shed, and the canines were erupting (Fig. 7, 17). One map WC the spontaneous correction of the midline from the first to the last photographs. Summary

1. The presence of the maxillary canine is vital to the function and esthetics of the dental complex. The availability of this tooth must be carefully considered during an orthodontic diagnosis. Lack of space is the most common cause of canine impaction. Other contributing factors are that this tooth has the longest period of development and that it is bigger, longer, and travels farther while erupting than any other tooth. 2. Proper management of unerupted canines is a challenge to the dental practitioner. Maxillary canines are found impacted to both the buccal and the lingual. Palatal impactions are much more common than labial impactions, but, of the two, labial impactions are more difficult to manage. 3. An appropriate surgical procedure which opens to the crowns of unerupted teeth is a key to uneventful orthodontic positioning of these teeth. Packing the follicular space with baseplate gutta-percha and keeping the crown open to the oral cavity with surgical JYondrPak is an effective method of making the tooth erupt into the oral cavity. 4. Modern preformed bands and improved cements make the placement of attachment on malposed teeth relatively easy. Direct bonding techniques are also of value in the management of unerupted teeth. 5. It is practical to move teeth orthodontically from seemingly impossible positions into ideal alignment. Such teeth will function normally, and no ericlence will be left of their original position or of their having been moved over long distances. REFERENCES

1. Atterbury, 55-61,

Robert

A.:

Treatment

of

uncrupted

palatal

cuspid

teeth,

Dent.

Survey

50:

1974.

2. Becker, Adrian, and Zilberman, Yerucham: A combined fixed-removable approach to the treatment of impacted maxillary canines, J. Clin. Orthod. 9: 162-169, 1975. 3. Cranin, A. N.: Aiding eruption of maxillary cuspids, Dent. Radiogr. Photogr. 41: 27, 1968. 4. Dewel, B. F.: The upper cuspid: Its development and impaction, Angle Orthod. 19: 79-90, 1949. 5. Fastlicht, S. : Treatment of impacted canines, Ahr. J. ORTHOD. 40: 981-905, 1954. 6. Genslor, Arthur M., and Strauss, Russell E.: The direct bonding technique applied to the management of the maxillary impacted canine, J. Am. Dent. Assoc. 89: 1332-1337, 1974.

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