American Journal of ORTHODONTICS Volume 68, Number

ORIGINAL

4, October,

1975

ARTICLES

An orthodontic approach to surgical problems James

P. Moss*

London, ETtgland

I

n many parts of Europe there has been a close association between orthodontics and oral surgery, and in many centers the orthodontist has been responsible for undertaking his own surgical procedures. As this situation is becoming more rare with increasing specialization, cooperation between these two specialities is becoming more important. In this article the orthodontist’s approach to the surgery necessary to correct local abnormalities of tooth position is presented. One of the most common orthodontic problems requiring surgery is the delayed eruption of a permanent tooth. The unerupted tooth presents most frequently in two situations: (1) in the child who has one permanent central incisor already erupted and is still waiting for the other one to erupt and (2) in the older patient who has a retained deciduous tooth. In this type of situation one should always ask: “Why is this deciduous tooth retained? Where is the permanent tooth?” Before undertaking any orthodontic surgery, minor or major, it is important to make a full diagnosis and treatment plan. The causes of noneruption of permanent teeth and the assessment of the position of the unerupted tooth and its treatment will be discussed. The orthodontist is frequently confronted with the problem of the missing upper lateral incisor and second premolar; occasionally even the canine may be congenitally absent. The noneruption of a permanent tooth is a frequently occurring situation which, provided the permanent tooth is not congenitally absent, may be caused by a variety of clinical abnormalities: (1) abnormal Read before Orthodontists *University

the seventy-fourth in Houston, Texas, College

annual meeting of May 19 to 22, 1974.

the

American

Association

of

Hospital.

363

364

Moss

Fig.

1A.

left

first

The

intraoral

permanent

view molar

of

this

over

9-year-old the

submerged

patient

shows ankylosed

the

mesial

upper

tilting left

of

deciduous

the

upper second

molar.

developmental position and impaction of the tooth, (1)) retained deciduous teeth, (3) supernumerary teeth, (4) trauma resulting in damage to the underlying tooth germ, (5) odontomas, (6) q&s. ant1 (7) tumors. Abnormal

developmental

position

and

impaction

of teeth

The most common tooth, other than the third molar, for impaction and noneruption is the caninc,27 particularly the upper canine. The reason for its displacement has been disputed. Hitchin’” believed that it is caused by inadequate dcvelopmcnt of the dental arch, but I)ewel” has pointed out that impaction most often OWLII'S in patients with good arches. lJa.ppin2” thought, that it, was initiatccl b\- lack of resorption of the deciduous canine, hut often the canine appears clisplacctl iii its position at an early age. Whatever the cause of the diq~lacernent, it, presents a common problem for the orthodontist. Bass’ found that uneruptctl canines accounted for 1.5 to 2.0 per cent of the orthodontic2 problems referred to an orthodontic consultant in southeast England. Retained

deciduous

teeth

Another common eausc of noneruption of a permanent tooth is the retained deciduous tooth. One central incisor ma?; erupt but eruption of the other is delayed because of a retained deciduous tooth. Roentgenograms show the permanent tooth to be prcscnt, lying in a good position, with normal morphology of its crown and root. The deciduous tooth may be discolored as a result of previous trauma which ran result in a pcriapical area or a certain amount of ankylosis and a dela,v in the resorption of the clccitluous tooth. These factors can cause dclaycd eruption of the permanent tooth. Pcriapical areas on deciduous teeth not only can cause the permanent tooth to bc displaced but also (aan cause some hypocalcification of the developing crown of the tooth if the area arises early enough. Eventually most permanent teeth will erupt, but they arc often displaced by the deciduous teeth. Another problem of the unerupted central incisor is that the lateral incisors

Volume Number4

68

Orthodontic

Fig. lg. An orthopantomogram second deciduous molar and

the

of the patient displacement

approach

to surgical

showing the ankylosis of the upper left second

of

problems

365

the upper premolar.

left

tend to drift mesially and encroach on the space for the upper central incisor. Adjacent teeth also drift in the premolar and canine region. The jaws gradually move farther apart and teeth are constantly erupting during the growth of the child. If a deciduous molar ankyloses, the eruption of the adjacent teeth causes the deciduous tooth to become submerged and it is not subjected to the normal occlusal forces which promote its normal exfoliat,ion. As the other teeth erupt they begin to drift mesially over the submerged tooth (Figs. 1.4 and 1B). If such a tooth becomes submerged it eventually becomes a problem not only from the orthodontist’s point of view but also from the surgical point of view, because the submerged tooth is now an impacted tooth. If a deciduous molar becomes ankylosed and submerged, the tooth should be carefully observed, extracted if necessary, and a space maintainer fitted. Supernumerary

teeth

A common cause of noneruption of a permanent upper incisor tooth is the presence of a supernumerary tooth. This supernumerary tooth develops as a palatal extension of the dental lamina and, because of the width of the alveolus in the incisor region, the supernumerary tooth tends to develop beneath the developing permanent incisor which occupies the basal region of the alveolar bone (Fig. 2). The supernumerary tooth can therefore prevent eruption of the upper incisor teeth. A supernumerary tooth may be any of one varying types-a mesiodens, a small peg-shaped tooth, a tuberculated supernumerary tooth, or even a supplemental tooth. The mesiodens often erupts and may cause displacement of the incisor teeth from their normal path of eruption. Trauma

resulting

in damage

to the

underlying

tooth

germ-dilaceration

Noneruption of the permanent teeth may be the result of trauma to the deciduous tooth which has then caused damage to the underlying tooth germ.

366

Fig.

Ness

2.

Diagram

Fig. 3. A diagram results in dilaceration

illustrating

illustrating of the

the

developmental

the intrusive type of permanent tooth germ.

position

blow

of

on

the

the

supernumerary

deciduous

tooth.

incisor

which

This cause of noneruption in the upper central incisor region often occurs following falls during the toddler stage. Often the child has been on a chair or stool, has slipped and fallen, and caught the incisors on the edge of a table. This blow is intrusive and drives the deciduous incisors up into the alveolus, resulting in dilaceration of the developing tooth germ (Fig. 3). A direct blow on the front of the tooth often has little effect on the underlying tooth germ, but an upward blow on the incisal edge can affect the tooth germ. If at the time of the accident the deciduous incisors have been driven into the alveolus the deciduous teeth should be removed and the buccal sulcus should be explored with the finger. Sometimes a fracture of the buccal alveolar plate can be felt projecting int,o the sulcus. In these cases manipulation of the fractured plate back

Volume Number

68 4

Orthodontic

approach

to surgical

problems

367

4. A, A roentgenogram of a patient with a compound composite odontoma preventing the eruption of the lower canine and lateral incisor. The lower deciduous canine and lateral incisor were retained. B, The patient 9 years after the removal of the compound composite ondontoma and the lateral incisor tooth.

Fig.

into position often pushes the teeth back into their correct position and dilaceration can be minimized. Automobile accidents also may be a cause of trauma to underlying tooth germs. The degree of dilaceration of the tooth germ depends on various factors: (1) the severity of the trauma, (2) the direction of the trauma, and (3) the age at which the trauma is inflicted. At a late age it may affect the root, and at an early age it will affect the crown. The direction of the blow will determine the direction in which the crown is displaced. Sometimes there is no history of trauma and yet the tooth appears to be &lacerated. It has been suggested that these are congenitally displaced teeth and that development of the root is prevented by the proximity of the palatal alveolar wall which causes deviation of the root in an upward direction.16, I8 Odontomas

The fifth cause of noneruption of a permanent tooth is the presence of odontomas. These may be of various types, the most frequent being the geminated odontomas and the compound composite odontomas (Fig. 4).

368

Uoss

Fig. 5. retained dentigerous

A,

This intraoral view shows the swelling of the buccal lower deciduous second molar. 6, The roentgenogram cyst associated with the unerupted second premolar.

The ma,jority of these odontomas eruption of the tooth. Occasionally tlic permanent series and in this instance, the tooth may be separated from the

plate of bone around reveals the presence

the of

a

cause a mechanical obstructiorl 10 tlich to a t oot,h in 1.hc otlontoma is g~lllilliltC(~ providctl the pulp casuals :II’(~ scparatc, h(l 1~cn~v~1. t)(iorltoma, which can thm,

cysts

Another cause of noncruption of teeth is the presence of cysts. I)cntigerous cysts or even periapical cysts on deciduous teeth can prevent eruption of the teeth. The teeth most frequently involvccl in a dentigerous cyst arc the lower molar and the lower premolars (Fig. 5). If crowding is present it is otten better to remove the tooth and the cyst completely. In large dentigerous cysts in the molar or premolar region the tooth germ is oftr11 badly misplaced and usually it is better to remove it. Tumors

Another cause of noneruption of the teeth is the presence of a tumor. These the tumors fortunately are extremely rare but occasionally they may prcverit eruption of teeth, especially in the upper incisor region. The tumor will need to be dealt with according to its particular type (B’igs. 611 and 6B). If, during the exposure of a tooth, when there is no other cause for its noneruption, the follicle is found to be thickened, this should always bc sent for histologic investigation. Assessment

of

the

position

of

the

unerupted

tooth

The method of assessment of the position of an unerupted tooth is similar for any tooth; the assessment of an uncruptcd canine will bc used to illustrate the

Orthodo&ic

approach

Fig. 6A. The intraoral film on the left shows the presence central incisor and a retained deciduous central incisor. shows the tooih after exposure and removal of the thickened

Fig. 68. A section through the thickened follicle columns of epithelium in the melanoameloblastoma. 10 years and there has been no recurrence.

showing The

to surgicat

problems

369

of an unerupted The intraoral film follicle.

upper on the

right right

the melanin pigment patient has been

among followed

the for

method. The following points will need to be assessed during the clinical examination, The amount of space in the arch. Is there sufficient room in the arch for this tooth to be brought down into its correct position? If there is inadequate space for it in the arch, consideration must be given to either reopening the space or extracting the teeth. Di Biase’ has shown that teeth with inadequate space in the arch erupt more slowly than teeth with adequate space. It is important, therefore, that adequate space for unerupted teeth should be made as soon as possible, especially in cases of delayed eruption of the permanent tooth. The morphology and position of adjacent teeth.. The morphology and position of the adjacent teeth should be taken into consideration. The first premolar can act as an adequate replacement for the canine tooth if it has a fairly short palatal cusp and a good buccal cusp and is in a good relationship with the

Fig. 7. This patient premolar is of good

fig. 8. premolar

has good morphology

Notice the difference on the right.

contact and

between the will adequately

in the

gingival

margins

lateral replace

of

incisor and the canine.

the

canine

first

on

premolar.

the

left

The

and

the

lateral incisor tooth. For some patients this is a perfectly acceptable replacement for the canine (Fig. 7). Another factor to be taken into consideration is the position of the gingival margins and the length of the upper lip. When the upper premolar takes the place of the canine, if the patient has a short upper lip, then the gingival margins of the teeth will be exposed when the patient smiles and, as the canine has a high gingival margin and the premolar a low one, from an esthetic point of view this may not be acceptable. For the majority of patients this is not important because the lipline is low and only the incisal edges of the teeth are seen in smiling (Fig. 8). Another important consideration is the size of the palatal cusp of the upper premolar. If it is larger or longer than the buccal cusp when the patient is viewed from the anterior aspect, the palatal cusp is seen jutting down between

vozunze Number

68 4

Orthodo&ic

approach

to surgical

problems

371

the buccal cusp and the lateral incisor and esthetically this is undesirable. As far as the position of the premolar is concerned, the more the premolar is rotated and the more the tooth is tilted mesially, the less pleasing the appearance; contact with the upper lateral incisor and orthodontic treatment may be necessary to align the tooth if the canine is extracted. The position of the adjacent teeth can often give an indication as to the position of the unerupted tooth. In the case of t,he unerupted canine, if the lateral incisor is tilted distally, roentgenographic examination will show that this is due to the pressure from the unerupted canine on the distal aspect of its root. If the lateral incisor is not only slightly tilted distally but also the incisal edge is tilted labially, roentgenographic examination will reveal that the canine is lying on the distolabial surface of this upper lateral incisor. fiony contours. The bony contours also indicate where the unerupted tooth is lying. If it is lying very high in the alveolus it will not displace the bony contours of the alveolar bone; if it is labially or palatallp placed it may be palpated. 3~0bility of teeth. The mobility of the erupted teeth may indicate that resorption of the roots of adjacent teeth has taken place. Canines map cause resorption of the roots of the lateral incisor teeth, resulting in their increased mobility. The canine that usually (*auses resorption is the one that is lying within the alveolar bone, in close proximity to the apical third of the lateral incisor root, and impacted against the root.17 VitaZity of teeth. Tt is important. to test the vitality of the adjacent teeth to determine whether they are nonvital and have a poor prognosis. The poor prognosis of an adjacent tooth may influence the decision regarding the treatment of the unerupted tooth. Roentgenographic

examination

An accurate assessment of the position of the unerupted tooth is essential to a satisfactory diagnosis and treatment plan. In order to do this two films must be taken, at right angles to one another, with a minimum of superimposition and distortion. The periapical and vertex occlusal views are the most useful films. When taking the vertex occlusal view a lead collar around the neck is used and the head is tilted backward to prevent irradiation of the gonads. Some workers suggest the use of a periapical and the lateral film which show the position of the unerupted anterior teeth very adequately in their relation to the floor of the nose. Ballard1 suggested that a lateral and a. posteroanterior view should be taken. These are satisfactory films provided the facilities for taking them are available but the disadvantages of these views are the superimposition of the vertebral column in the posteroanterior view and the lack of detail. Whichever films one takes it is essential to be able to see the following. The position and morphology of the apex of the tooth. The position of the apex needs to be accurately located. On the intraoral film three imaginary lines should be drawn : (I) the longitudinal axis of the first premolar, (2) the longitudinal axis of the lateral incisor, and (3) a line approximately 2 to 3 mm, above the apices of the teeth. If the apex lies outside those three lines the tooth has

372

.lf ass

a pool. prognosis for erupting into ;I Il~~~~~lill position. I I’ it is ;~i),rvcatlrca lilac which is 2 to 3 mm. abow the apices of’ the twth t tlc11 tIlc> prognosis. cy~~G;~tt!~ in the older patient, for the tooth fi~li~lt~ erupting ilIt- its llormi~t oc+c~tns;~l position is also poor. If’ the ;tpc’s tics outside the lo~lgitu(till:tt axis of the firsi I)t’omolar and the latclral incisor or outsi&> thr eontours 01’ the :I rc.11, OIIW again the prognosis for the positioning of’ t IIP tooth is I)OCII~lllltcss fisrcI apptiancc‘ therapy is used. The morphology of the root is important from the> surgical point ot’ view. If the pulp canal shows a right-angled bcntl this intlicatcs that the root has a hook on it and may therrforc he difficult to remorc~ ant1 align. The IKLGtioH o?!d nzo,pholOg~j of t77fJ (‘Wii’11. The s~ontt cdonsidcratioll is the position of the crown and its influence on thtl lataetccl against the tooth, or is it palatally plac~l ant1 not impa($cd? The morphology of the crown of the canine is usually goocl but ill the ww of a central incisor it may be malformed or hypoplastic ant1 this will influcn~c~ the tlcc+ioii as to whether the tooth shoultl bc alignetl or ostractc~tl. The cZirecfio,l of the 7oy&di~~al tr.cis. The third facdtor that must IW assessed is the direction of the longitudinal axis, for this wilt clrtt*rminc t,hc tlircetion in which the tooth will erupt. \\‘ill the tooth impact as it erupts and, when thcl tooth has erupted, will the ii JWS bc in ;I c*orrc~ctposition Y The

treatment

of unerupted

teeth

The t,reatment of an uneruptcd tooth wilt drpcntl oJI its stat,c, its positioll, and whether there is enough room in t,hc dental arch to i~c(‘oJ~~nlotlatcit. There are various methods of dealing with th(l uncruptc~tl tooth. Remova of the obsfructio)t trod exposure. Ankylosctl tlec*iduous teeth need to be removed, and if this is done early (lnough no esposurc of t>hc permanent tooth is necessary. l-f eruption has bclcn dclayrcl th(L permanent tooth should be exposed because it is important to allow tlicl tooth to erupt iirto its correct position as soon as possible. Supernumerary teeth and odontomas provide mechanical obstruc+ions to the eruption of the t&h and these should he removed at the age when the uncruptcd permanent tooth should halt erupted. The position of thr suI)(‘rJ~11111Cr;1r!tooth or odontoma and tlif uncrupted pcrrrranc~nt, tooth must, bc arc*uratclly asscssrd. Supernumerary

teeth

A recent investigation has been undertaken to assess the rrsults of the buecal or palatal approach to the removal of supcrnumcrayv teeth and thcl osposurc of incisor teeth. From investigation of twenty-fivcx (.ElS(‘S it \VSS iI~)~XlWllt tllat tile l)CSl approach for supernumerary teeth was the palatal approach. The raising of tht buccal periosteum often leaves the incisor tooth with a very high gingival margin (Figs. 9d and 9B). These findings confirm the observations of Di Biase.l The removal of the supernumerary teeth thercforc should be undertaken from a palatal approach, if possible, and a palatal flap should be raised. The deciduous teeth should be removed and the overlying bone removed with chisels nndcr band

Volume Number

Orthodontic

68 4

approach

Fig. 9A. The intraoral roentgenogram on the right preventing the eruption of the upper central incisor. left shows the tooth 15 years after the supernumerary by a buccal approach.

Fig. 9B. Intraoral buccal approach.

view Notice

15 years the high

to surgical

shows a conical The intraoral was removed

after the removal of the gingival margin associated

problems

373

supernumerary tooth roentgenogram on the and the -( 1 exposed

supernumerary with this

tooth

by

a

tooth.

pressure. Once the bone has been removed and the supernumerary tooth has been located and identified, the supernumerary tooth is removed and special attention is paid to the removal of the follicle as it is possible that another supernumerary tooth may develop if the follicle is not removed completely. If there is any delayed eruption of the permanent central incisor or the underlying permanent tooth, these teeth should be exposed. Bone around them should be removed down to the amelocemental junction and then the area should be packed with a Whitehead’s varnish pack on 1/2 inch ribbon gauze. This is packed around and over the tooth and is replaced after 10 days with a BIPP (bismuth iodoform paraffin paste) pack if the permanent teeth are not likely to erupt immediately. In the same series of cases those teeth which had been packed erupted within

Fig. 10A. This intraoral film shows around the crowns of the unerupted

Fig.

1OB.

A photograph

of

the

the retained central and

patient

taken

deciduous incisor lateral incisors.

after

marsupialization

and

a dentigerous

and

eruption

cyst

of

the

teeth.

6 to 8 weeks, whereas those which had been exposed but not packed open took 6 weeks to 18 months to erupt. This may be due to the contraction of scar tissue which Di Biase* showed delayed the eruption of incisors. Exposure. The unerupted tooth should be exposed if the tooth is delayed in and it is lying in a favorable position with adequate its eruption and could erupt space in the arch. It is important, during the exposure of the tooth, that certain rules be applied : (1) the tooth must be adequately exposed by sufficient removal of bone and overlying mucosa, (2) the bnccal periosteum should remain intact

Volume Number

Fig.

68 4

11A.

incisors

Fig. means

Orthodontic

This had

11B. of

patient

had

noneruption

of

the

the

taken

approach

upper

central

to surgical

incisors.

problems

The

upper

375

lateral

erupted. A an

photograph apically

of

repositioned

patient

after

exposure

of

the

central

incisors

by

flap.

during the exposure if at all possible, and (3) the exposure must be maintained. An incision is made along the gingival margins that the tooth will have when it erupts on the buccal side and then a palatal flap is raised and the tooth is adequately exposed down to the amelocemental junction by removing the bone with chisels. Chisels are preferred to burs as there is less likelihood of damage to adjacent teeth. Bone can also be removed in the direction in which the tooth needs to he moved in order to align it. Before the flap is repositioned it is trimmed so that it lies in contact with the new bony surface. A Whitehead varnish pack is then used to pack the mucoperiosteum against the bone. This can also be used as an orthodontic wedge if the crown of the tooth is slightly impacted. The pack is sutured in with a mattress suture and is then left for 10 days. The mattress suture and the pack are removed after 10 days and, if necessary, a further pack is inserted, impregnated with BIPP, and left in place for another 10 days. It is most important that the exposure of the tooth be maintained. In older patients the final stages of the eruption of the tooth are often very slow.

376

Moss

Fig. 12A. The two upper intraoral radiographs show teeth preventing the eruption of the central incisors. gram shows the position of the central incisors after right intraoral roentgenogram shows the position

the presence of two supernumerary The lower left intraoral roentgenoexposure and packing. The lower of the teeth after alignment.

Teeth which are involved in a tlentigerous q-st sometimes need to be removed but often, especially in the anterior region, (aan he exposed. The cyst should not be enucleated unless the involved tooth is being extracted. The cyst should be marsupialized and the tooth packed open and allowed to erupt. If the cyst is marsupialized eruption occurs quickly but if the follicle and cyst lining are removed this often results in delayed eruption of t,hc teeth (Figs. ZOA and 1OB). In the upper central incisor region some incisors do not erupt and yet they appear to be placed just beneath the mucosa. These teeth appear to have erupted buccally and become caught at the mucogingival reflection. In t,his case an apically repositioned flap should be employed so that a keratinized epithelial lining is found buccally at the gingival margin. This is a simple operation and prevents the advent of periodontal problems in later life (Figs. 11~1 and 11B). Sometimes, following the exposure of t,eeth, the teeth may become impacted against one another and may need a simple orthodontic appliance to disimpact them (Figs. 12A to 12E).

Volume Number

68 4

Orthodontic

Fig.

Fig. teetl

12C.

An

128.

An

intraoral

intraoral

view

view

showing

showing

the

the

approach

position

orthodontic

to surgical

of the

appliance

teeth

inserted

1.

Fig.

12D.

The

intraoral

view

1 month

after

later.

problems

377

exposure.

to

disimpact

the

Fig.

12E.

The

intraoral

view

after

the

appliance

Fig. 13. A, This patient had a wire lasso placed around the upper central incisor, which was horizontal. The end which then engages a spring on a removable appliance. patient after the central incisor had been brought down.

had

the of

been

removed.

amelocemental the wire is bent 6, An intraoral

junction of into a hook view of the

Exposures and adjuncts. Another method of treatment for the unerupted tooth is to expose the tooth and then attach something to move it into position. StrockzG advocated the fitting of a c.rown to the unerupted tooth in order to align it. Day5 suggested the fitting of a wire loop into a prepared cavity in the tooth. KettleI” suggested pinning the teeth. Direct bonding has also been used to allow the attachment of a bracket to an exposed unerupted tooth. Whatever the method of tooth alignment employed, the following criteria are important: There must be adequate space in the arch; the tooth must be able to erupt; there must be adequate exposure of the tooth ; the exposure must be maintained ; the buccal periosteum should remain intact, if at all possible, in order for this type of treatment to be undertaken. If the tooth is in an unfavorable position a wire lasso can be inserted around the amelocemental junction. This is made of 0.5 or 0.7 mm. soft stainless steel wire, which is twisted around the neck of the tooth and then is twisted together so that it projects down into the oral cavity and is then formed int,o a hook. A

VoZume Number

68 4

Fig. 14. cisor 1 year after

Orthodontic

The

prior

upper to

after repositioning.

intraoral

roentgenograms

repositioning. repositioning Notice

The and the

lower the

lower

obliteration

approach

show left

the

position

roentgenogram right of the

shows

roentgenogram pulp

to surgical problems

of

the the

shows

upper repositioned the

tooth

379

central

intooth

3 years

canal.

removable or fixed appliance is then used to attach an elastic or spring to the tooth (Fig. 13). Brackets which have been directly bonded to the tooth can be attached to either elastic or a wire and then to an orthodontic appliance. Extraction. The unerupted tooth may be extracted. If it is lying in an unfavorable position, and there is inadequate space for it in the arch, and the adjacent teeth are in a good position and of good morphology, then it is probably better to remove the tooth. Teeth which are of poor morphology or are involved in a tumor may also need to be extracted. Sometimes if the tooth is lying very high in the alveolus, and the extraction would damage or jeopardize the vitality of the adjacent teeth, it is better to leave it and to keep it under observation by periodic roentgenographic esamination. If there is inadequate space in the arch, if the position and morphology of the adjacent teeth are good, and if the adjacent teeth can be brought into or are in a good position relative to one another, then the uncrupted tooth should hc extracted.

Fig. 15A. The upper left intraoral roentgenogram was taken at 4 years. Notice the periapical area associated with the root of the upper deciduous incisor. The upper right roentgenogram was taken at 5 years, following the extraction of the deciduous central incisor. Notice the position of the central incisor. The two lower films were taken at 7 and 8 years. Notice the curve on the root of the tooth.

Repositioning. Still another method of trea,tment for the unerupted tooth is what is known as repositioning, which has been described by Holland,l,* Cowan and Keith,4 and McKay.21 In order to reposition a tooth (1) there must he adequate space, (2) the apex must be in a correct position so that the tooth can bc rotated round the apex, and (3) the apex should be open and therefore the operation nt~ls to be done at an early age. Following this treatment the prognosis for the tooth is good. This method is particularly applicable to anterior teeth, especialp upper incisors which show signs of dilaeeration. It is important to assess the position of the tooth and the degree of dilacerations; then one can decide on the method of t,reatment. (Fig. 14). The dilacerated tooth can be treated in several ways. If the tooth is delayed in eruption time, and only the crown or the tip of the root is partiall) dilacerated, and there is adequate space in the arch, then exposure of the tooth will allow it to erupt into position. If, however, the crown is badly dilacerated and would not be esthetically

Volume Number

Fig. the

68 4

15B. pulp

Orthodontic

The

tooth

1 year

and

3 years

after

approach

transplantation.

to surgical

Notice

the

problems

381

obliteration

of

canal.

satisfactory, or if it is badly positioned and displaced from the arch with inadequate space in the arch, it may be better to remove the tooth at this time. The removal of a dilacerated tooth is often the treatment of choice in the older patient. When the patient is referred at an early age it is possible to reposition the whole follicle within the alveolar bone. This should be undertaken only if the root is open and only the crown is formed and, therefore, must be done at a fa,irly early age. At a later age the tooth can be uprighted, leaving the apex in the same position, provided the dilaceration is not severe. A flap is raised, the bone is removed with chisels, and the follicle is completely exposed. The tooth is then rotated with its follicle and the flap is sutured back into place. This type of treatment seems to be very satisfactory and the tooth erupts quite normally. If the patient is older, and the root is becoming dilacerated, and yet there is adequate space in the arch, an alternative method is to transplant the tooth. In these cases a splint is made and the tooth transplanted in a manner similar to the transplantation of the upper canine. These teeth seem to retain their vitality and the prognosis for them seems to be extremely good (Figs. 158 and 15B). Tramplantatiow The transplantation of unerupted teeth has been undertaken for many years. In 1915 Widman, a Swedish oral surgeon, reported the autogenous transplantation of upper canines followed by their root filling, and since then many others have reported similar operations.“, 12,-2 =, =, ?’ The transplantations that the author has undertaken over the past 10 years are those in which the tooth is not root filled at t,he time of operation. The tooth is root filled only if it shows signs of periapical rarefaction following the operation. The criteria for transplantation are that there must be adequate space in the arch for the tooth and the tooth must be able to be removed whole without undue trauma. It is suitable particularly for the older patient who requires a minimal amount of treatment with a good arch and who has a retained deciduous tooth.

382

Fig. raised;

The

dloss

16,

A to F. The C, canine

stages

exposed;

in the

D, bone

transplantation chips

being

of inserted;

the

canine.

E, flap

A, Before; 6, palatal flap F, splint cemented.

sutured;

method

Once there is adequate space in the arch for the unerupted tooth, an impression of t,he arch is taken and a cast-silver or acrylic cap splint is constructed. It teeth, a.nd around the tooth to bc transplanted it is an covers the two adjacent ope11 cap. Small holes are tlrilled into the occlusal surface of the other teeth, as this allows the cement to escape and also enables the operator to know when the splint is seated accurately. The open cap around the replica of the t,ooth allows the operator then to position the tooth in the correct place while the cement is setting. Under general or local anesthesia (%anest with Octapressin is injected into the area of the canine. This controls the bleeding, constricts the vessels of the pulp of the tooth, and helps in the transplantation.

Volume Number

68 4

Orthodontic

Fig. 166. The upper 1 year after

after

intraoral transplantation.

transplantation.

Notice

roentgenogram The lower the

obliteration

approach

shows the roentgenograms of the

pulp

to surgical problems

position show

383

of the canine before and the tooth 3 and 8 years

canal.

An incision forming the gingival margin for the transplanted tooth is made when the palatal flap is raised. The bone is carefully removed with chisels and all the bone which is removed is kept in warm normal saline solution and is used as bone chips at the end of the operation. When the crown of the tooth has been exposed the bone adjacent to the root is also removed so that the tooth can be removed with as little trauma as possible. The new socket for the tooth is cut in the alveolus with a hammer and chisel, and sometimes it is necessary to remove the canine and to place it under the palatal flap while the new socket is being cut. When the new socket is deep enough the tooth is carefully removed and placed in the new socket in its correct position. The bone chips are then replaced around the root of the transplanted tooth and the flap is sutured with black silk sutures. It is important that the sutures be placed accurately and, if black silk is used rather than a resorbable suture, that the suture be placed well away from the gingival margin so that when the splint is in place the sutures can be removed easily. Once the tooth is in position, the splint is cemented with germicidal cement

Fig.

16H.

The

intraoral

view

shows

the

tooth

8 years

after

transplantation.

and while the cement is setting the final position of the tooth is checked (Figs. 1624 to 16H). The patient is given an antibiotic cover for 5 days and the sutures are removed I week later. The splint is left in position for approximately 6 weeks and is then removed. At the time of splint removal it is important to grind the tooth free of the bite, especially in labial excursions of the: jaw, although the tooth at this stage is quite firm. The results of these canine transplants over the past 10 years have been carefully assessed but, as with all long-term surveys, many patients do not always return for their follow-up appointments. Also one wonders whether the patients who do return are those who have trouble or who arc pleased with their results; either way, the results may 1~ slightly biasecl. Posttrea,tment

assessment

In this article two series of fifty patients each arc presented : in (1roup A are those 3 to 10 years out of retention and in Group R arc those 1 to 3 years out of retention. The results were assessed according to the criteria of Fang,!’ Clark, Tam, and Mitchell,3 and Fong and Agnew’” and were also given a prognosis rating. This rating was based on clinical experience as to whether the tooth has a good prognosis and will remain with the patient indefinitely or whether the tooth shows signs that it is going to be lost. Eleven factors were taken into consideration when assessing the results. The first was position, whether satisfactory or poor, and the second was contact with adjacent teeth. Obviously, in some cases, where the space was more than adequate or where it had been reopened too much, contacts following the operation would not have been present but would have been established with the normal mesial migration of the teeth. The third factor assessed was whether the teeth were loose or showed any abnormal mobility. The fourth factor was the color, that is, whether the tooth had darkened during the years out of retention. The fifth was the vitality of the tooth, which was tested both thermally and by the electric pulp tester. It is very difficult to know whether these teeth are responding t,o

Volume Number

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Orthodontic

approach

to surgical

problems

385

Vitality

Fig. 17. A diagram creased

vitality;

N,

illustrating the normal vitality.

Pulp

vitality

of

the

two

groups.

NV, Nonvital;

DV, de-

Chamber A

Fig. 18.

A diagram

change;

E, enlarged.

illustrating

the

effect

on

the

pulp

chamber.

D, Decreased;

NC,

no

vitality tests or whether the response comes from the periodontal membrane. The sixth factor was whether the pulp chamber showed any signs of a reduction in size. The seventh factor was whether there was any resorption of the root, and then the gingival condition was estimated as to whether there was any inflammation or pocketing present. The periodontal membrane, the lamina dura, and the alveolar bone were all assessed roentgenographically as either complete or incomplete. Of the fifty teeth that had been 3 years out of retention (Group A), 46 were in a good position, three were firm, and one was poor. Only 32 had good contacts on both sides and, of the others, five had a mesial contact, seven a distal contact, and six no contact at all. Regarding the mobility of the teeth, forty-six showed no abnormal mobility and four were mobile (three of these had to be extracted). There were thirtyfour of normal color, thirteen slightly darker, and three definitely dark (Fig. 21). Regarding the vitality tests, twenty-eight in Group A were normal, twelve had a decreased vitality, i.e., they responded to vitality tests but this was not the same as the response of the tooth on the opposite side, and ten were nonvital (Fig. 1’7). Regarding closure of the pulp chamber, twenty-one showed a decrease in the size of the pulp chamber and twenty-nine showed no change at all (Fig.

386

Moss

Fig. 19. The transplantation. plantation.

upper intraoral roentgenograms show the canine before and 1 year The lower roentgenograms show the canine 3 and 7 years after Note the nonprogressive resorption on the distal aspect of the root.

after trans-

18). Thirty-one showed no resorption at, all; of the others that showed resorption there were two types. One was a, limited resorption which occurred usually on the distal aspect of the tooth near the region where the alveolar bone would have perhaps damaged the cementum during the removal of the tooth and this resorption did not progress (Fig. 19). Eleven cases fell into this category. There was another form where there was gross resorption which seemed to be progressive and nothing seemed to stop it, not even root filling the tooth, and this was found in eight cases (Fig. 20). The gingival condition was excellent in forty-seven of the cases and in three of the cases there was a pocketing of 3 mm. or more. Assessment of t,he periodontal membrane and lamina dura showed that ten had an incomplete periodontal membrane and lamina dura and forty were normal. Regarding the alveolar bone, forty were normal and ten showed some rarefaction in the area of the canine. According to the criteria of Fang,” Clark, Tam, and Mitchell,” and Fong and Agnew,lO thirty-one were successful (62 per cent). According to the

Orthodovdic

approach

to surgical

problems

307

Resorption

Fig. 20. A diagram nonprogressive slight

illustrating resorption;

the resorption R, progressive

found in the resorption.

two

groups.

N,

Normal;

SR,

Colour A

Fig. 21. A diagram dark; D, dark; N,

illustrating normal.

the

B

changes

in color

of

the

transplanted

teeth.

SD, Slightly

Prognosis B

A

Fig. 22. A diagram E, extracted.

of the

results

based

on the

prognosis

rating.

G, Good;

F, fair;

P, poor;

prognosis rating, thirty-four of the fifty teeth (68 per cent) had a good prognosis, seven had a fair prognosis, six had a poor prognosis, and three had already been removed (Fig. 22). Assessment

of

consecutively

treated

cases

For the sake of comparison, fifty consecutive cases which had been operated on were assessed. All in this group had been 1 to 3 years out of retention. The results were very similar to those in Group A but there were some differences. One difference was in the color of the transplant following operation. In Group B the color was normal in forty cases, compared with thirty-four in

Fig. 23. A roentgenogram after transplantation.

of a patient

with

transposition

of the

upper

canine

and

2 years

Group A, and this perhaps indicated that the teeth tend to become darker as time elapses (Fig. 21). There was a difference in vitality : Thirteen in Group B showed a normal vitality, twenty-two showed a decreased but positive vitality, and fifteen were nonvital (Fig. 17). Over a period of 2 years or more the tooth does seem to regain its vitality.24 Rock and associatesz5 showed that 55 per cent of traumatized anterior teeth which were nonvital at the time they were first seen were vital after 2 years. This may explain why there is a difference between these fifty cases and those over 3 years out of retention. There were similar differences with regard to the decrease in the size of the pulp chamber: thirty-five showed no change and fourteen showed a decrease in size (Fig. 18). This perhaps indicates that, the pulp does not begin to respond imof osteodentin but that this occurs later. The mediately with the laying down pattern of resorption of Group B was almost identical to that of Group A : thirtyone cases showed no resorption, thirteen showed limited resorption, and six showed progressive resorption. It seems, therefore, that the percentage showing resorption does not increase with age (Fig. 20). Only twelve teeth were classified as being vital; twenty-three had a decreased but positive vitality; fifteen were nonvital; therefore only 24 per cent would be classified as being successful. Thirty-six of them had a poor prognosis, five had a fair prognosis, seven had a poor prognosis, and two had been extracted (Fig. 22). From these results it is evident that Groups A and B show similar patterns. Transplantation does have a place in orthodontic treatment and is useful,

Volume Number

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Orthodontic

approach

fo surgical

problems

389

especially in the older patient who requires a minimum amount of treatment and who would not tolerate a prolonged course of orthodontic treatment. Transposition is another instance in which transplantation is a valuable adjunct to orthodontic treatment. Sometimes an upper canine is transposed into the upper second premolar region and is lying in a vertical position. Often the deciduous canine is retained anteriorly, and in these situations the orthodontic problem of moving the canine through the alveolar bone is extremely difficult. IJnder these circumstances a much easier method of treatment is to remove the canine and transplant it directly into its correct position in the alveolus. In these cases a large buccal flap is raised (not a palatal flap), the gingival margins for the tooth are cut, and the alveolar bone is then prepared for the reception of the transposed canine (Fig. 23). The method used is the same as for the transplantation of a palatally displaced canine, except that a buccal flap is raised. Summary

The various causes of noneruption of teeth have been described and the methods of clinical and roentgenographic examination have been discussed. The methods of treatment for the unerupted tooth have been described and discussed, and the results of 100 cases of the autogenous transplantation of permanent canines without root filling have been reported. REFERENCES

1. Ballard, C. F.: Discussion of The clinical assessment of the unerupted maxillary canine, Trans. Br. Sot. Study Orthod. 90, 1955. 2. Bass, T.: Observation on the misplaced upper canine tooth, Dent. Pratt. 18: 25, 1967. 3. Clark, H. B., Tam, J. C., and Mitchell, D. F.: Transplantation of developing teeth, J. Dent. Res. 33: 653, 1954. 4. Cowan, D., and Keith, J. E.: Surgical positioning of unerupted maxillary canine: A preliminary report, Dent. Pratt. 11: 341, 1961. 5. Day, A. J. W.: Unerupted teeth which have been surgically exposed and brought into occlusion, Trans. Br. Sot. Study Orthod. 76-82, 1946. 6. Dewel, B. F.: Upper cuspid: Its development and impaction, Angle Orthod. 19: 79, 1949. 7. Di Biase, D. D.: Midline supernumeraries and eruption of the maxillary central incisor, Dent. Pratt. 20: 35, 1969. 8. Di Biase, D. D.: Mucous membrane and delayed eruption, Trans. Br. Soe. Study Orthod. 5: 149, 1970. 9. Fong, C. C.: Transplantation of the third molar, Oral Surg. 6: 917, 1953. 10. Fong, C. C., and Agnew, R. G.: Transplantation of teeth: Clinical and experimental studies, J. Am. Dent. Assoc. 56: 77, 1958. 11. Fordyce, G. L.: Surgical problems of orthodontic interest, Dent. Pratt. 15: 388, 1965. 12. Heslop, I. H.: Autogenous replantation of the maxillary canine, Br. J. Oral Surg. 5: 135, 1967. 13. Hitchin, A. D.: Impacted maxillary canine, Dent. Pratt. 2: 100, 1951. 14. Holland, D. J.: Surgical positioning of unerupted, impacted teeth (surgical orthodontics), Oral Surg. 9: 130, 1956. 15. Hovinga, J. : Auto-transplantation of maxillary canines: A long-term evaluation, J. Oral Surg. 27: 701, 1969. 16. Howard, R. D.: The congenitally displaced maxillary incisor: A differential diagnosis, Trans. Br. Sot. Study Orthod. 5: 31, 1969.

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Am. J. Orthod. October 1976

Moss

17. Howard, B. I).: The displaced maxillary canine : Positional variations associated with incisor resorption, Dent. Pratt. 22: 279, 1973. 18. Howe, G. : Minor oral surgery, Bristol, 1971, John Wright & Company. 19. Kettle, M. A. : Treatment of the unerupted maxillary canine, Dent. Pratt. 8: 245, 195% 20. Lappin, M. M.: Practical management of the impacted maxillary cuspid, AN. J. ORTHOD. 37: 769, 1951. 21. McKay, C.: Surgical orthodontics applied to the unerupted maxillary canine, Br. Dent. J. 110: 231, 1961. 22. Moss, J. P.: Autogenous transplantation of maxillary canines, .J. Oral Surg. 26: 775, 1968. 23. Moss, J. P.: Autogenous transplantation of maxillary canines without, root filling, Studiemeek, Nederlandse Vereniging voor Orthodontische Studie 164, 1970. 24. Moss, J. P.: The unerupted canine, Dent. Prrtct. 22: 241, 1971. 25. R.ock, W. P., Gordon, P. H., Friend, L. A., and Grundy, M. C.: The relationship between trauma and pulp death in incisor teeth, Br. Dent. J., p. 236, March 19, 1974. 26. Stroek, M. S.: A new approach to the unerupted tooth by surgery and orthodontics, AM. J. ORTHOD. 24: 626, 1938. 27. Thoma, K. H.: Oral surgery, ed. 3, St. Louis, 1958, The C. V. Mosby Company, p. 389. 28. Thonner, K. E., and Meijer, M.: Auto-transplantation of impacted upper canines. A clinical and histological investigation, Odontol. Tidsskr. 77: 113, 1969. Mortimer

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An orthodontic approach to surgical problems.

American Journal of ORTHODONTICS Volume 68, Number ORIGINAL 4, October, 1975 ARTICLES An orthodontic approach to surgical problems James P. Moss...
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