ADULT ORTHODONTICS

Introduction

History

In 1880 Kingsley, after treating a 40 year old patient for

anterior cross-bite stated, “It may be regarded as settled that

there are hardly any limits to the age when movement of teeth

might not succeed”.

But he maintained, “The action is slower, growing more and

more difficult and in cases where a considerable number of teeth

are to be moved, the results become more and more doubtful with

advancing years”.

In 1901 Mac Dowell wrote, “After the age of 16 years, a

complete and permanent change in transition of occlusion the

author believes to be almost impossible. There may be a case or

two of rare exceptions but as a rule the change cannot be

accomplished successfully owing to the development of the adult

glenoid fossa and the density of the bones and muscles of

mastication”.

In 1912 Lischer summarized, “Recent experiences of many

practitioners have ------ us to a better appreciation of the ‘golden

age of treatment’, but that we mean that time in an individual’s

life when a change form the temporary to permanent dentition

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takes place. This covers the period form the sixth to the 14 t h

year”.

In 1921 Case demonstrated an efficient space closure, for a

patient with pyorrhea in the lower anterior area. However, in the

past 3 decades, a major reorientation of orthodontic thinking has

takes place. The following are some of the reasons for the

increased interest by the orthodontics in adult patients, as well as

several causes for increased interest shown by adults in

orthodontic treatment

Improved appliance placement techniques

More successful management of TMJ joint symptoms

Effective management of skeletal jaw dysplasias using

advanced orthognathic surgical techniques

Reduced vulnerability to periodontal breakdown as a result

of improved tooth relationship and occlusal function

ADULT ORTHODONTIC TREATMENT OBJECTIVES

1. Parallelism of abutments

The abutment teeth must be placed parallel with the other

teeth to permit insertion of multiple unit replacements. A

restoration will have a better prognosis when the abutments are

parallel before tooth preparation, as it facilitates the transfer of

masticatory forces along the long axis of the tooth.

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2. Most favorable distribution of teeth

The teeth should be distributed evenly for replacement of

fixed and reasonable prosthetic in the individual arches.

3. Adequate embrasure space and proper root position

The anatomic relationship of the roots is important in the

pathogenesis of periodontal disease. Creation of adequate

embrasure space and proper root position allows for better

periodontal health, especially when the placement of restoration

is necessary.

4. Better lip competency and support

When adequate support is not given to the upper lip by the

upper incisors, it may create a change in the anteroposterior and

vertical positioning of the upper lip and increases wrinkling.

This often makes the face prematurely aged and is a major

concern for adults especially women, who are usually anxious

about changes in upper lip.

In cases requiring anterior restorations, retraction is

recommended to achieve lip competency while maintaining lip

support.

5. Improved crown/root ratio

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6. Improvement or correction of mucogingival and osseous

defects

Proper repositioning of the prominent teeth in the arch

which improves gingival topography.

ADJUNCTIVE ORTHODONTIC THERAPY (6 months

maximum)

By definition, adjunctive orthodontic treatment refers to the

tooth movement carried out to facilitate other dental procedures

to control disease and restore function.

(E.g.) Congenital absence of II premolar with mesial

migration of first molar. An orthodontist distalises the first

permanent molar to replace a satisfactory pontic in second

premolar area.

Physiologic occlusion

Physiologic occlusion, although not necessarily an ideal or

class I occlusion is one that adapts to the stresses of function and

can be maintained indefinitely.

Pathologic occlusion

It is one which cannot function with contributing to its own

destruction. A pathologic occlusion may manifest itself by any

combination of

Excessive wear of the teeth with sufficient compensatory

mechanisms.

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Temporomandibular pain/dysfunction

Pulpal changes ranging from hyperemia to necrosis

Periodontal damage

For example, when a tooth is lost the adjacent teeth tend to

drift, tip and rotate. Whether this requires orthodontic correction

will depend upon whether the sings of pathologic occlusion are

present. If the patient can still maintain adequate plaque control

and if the occlusal forces are within the physiologic tolerance of

the support mechanism, and if the patient can function with

prematurities or functional shifts, then the occlusion may be

considered physiologic and the only indication for orthodontic

treatment could be the patient desire for improved esthetics.

Goals of adjunctive treatment

Facilitate restorative treatment by repositioning the teeth in

ideal positions.

Improve the periodontal health by eliminating plaque

harboring areas.

Establish favorable crown to root ratios

Position the teeth so that occlusal forces are transmitted

along the long axis of teeth

Principles of adjunctive orthodontic treatment

1. Diagnostic and treatment planning considerations

Planning for adjunctive treatment requires two steps

Collecting an adequate database

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Developing a clearly stated list of the patient problems

taking care not to focus unduly on any one aspect of the

complex situation.

The patients motivation for and expectations of treatment,

general dental awareness, enthusiasm for the proposed treatment

and ability to cooperate with the treatment regimen all must be

evaluated.

Diagnostic records

Records usually include individual intra-oral radiographs to

supplement the panoramic films that usually supplies for

younger and healthier patients.

Pre-treatment cephalometric radiographs are usually not

required

Dental casts obtained from fully intended impressions

should be acquired.

Once all the problems have been identified and categorized,

special attention must then be turned to tooth positions that

require modification. The key treatment planning question is –

can the occlusion be restored within the existing tooth positions

or must some teeth be moved to achieve a satisfactory, stable,

healthy and esthetic result? The goal of adjunctive treatment is to

produce physiologic occlusion and facilitate other dental

treatment and has little to do with the angles concept of ideal

class I tooth relation.

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As a general guideline, adjunctive orthodontic treatment

that would take more than 6 months should be avoided as it

clearly indicates a need for comprehensive orthodontic treatment

involving all the teeth.

Biomechanical considerations

In adults, the absolute magnitude of forces used to move

teeth must be reduced when periodontal support has been lost, to

prevent damage to periodontal, bone, cementum and root. In

addition, the smaller the area of supported root and farther the

CRes of the tooth.

CRes of a single rooted tooth is at approximately 6/10 t h the

distance between the root apex and the alveolar crest, from the

root apex. Apical relocation of the C Res increases the magnitude

of the tipping moment (M), for a given tone and consequently a

large countervailing couple (M) would be necessary to effect

bodily movement.

The recommended brackets for adjunctive treatment is 22

slot-edgewise brackets because rectangular slot permits control

of buccolingual axial inclination, the wider brackets permit

control of rotations and tipping.

Removable appliances can be used in situations where a

number of teeth are missing. They permit the reaction forces to

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be spread over adjacent supporting tissues such as the palatal

vault, alveolar mucosa as well as the anchor teeth.

If many teeth are missing, this approach may be the only

way to generate anchorage.

Bracket placement when placing a partial fixed

appliances for adjunctive treatment, the brackets are placed in

the ideal positions only on teeth to be moved and the remaining

teeth to be incorporated in the anchor system are bracketed in the

most convenient way possible, with the arch wire slots closely

aligned. Passive engagement of wires to anchor teeth produces

minimal disturbance of teeth that are in a physiologically

satisfactory position.

3. Timing and sequence of treatment

After the development of a treatment plan the first step is

the control of nay active dental disease.

Periodontal management before any orthodontic

treatment, destructive periodontal disease must be controlled,

because orthodontic tooth movement superimposed on poorly

controlled periodontal health can lead to rapid and irreversible

breakdown of the periodontal support apparatus. And also

periodontal therapy should be continued even after orthodontic

treatment is started. Scaling, curettage and gingival grafts should

be undertaken, before any tooth movement is done. Clinical

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studies have shown that orthodontic treatment of adults with

compromised periodontal tissues can be completed without loss

of attachment, provided there is good periodontal therapy both

initially and during tooth movement. Surgical pocket elimination

and osseous surgery should be delayed until completion of

orthodontic phase, because a significant amount of soft tissue

and bone recontouring occurs during orthodontic tooth

movement.

Endodontic treatment before any tooth movement, active

caries and pulpal pathology must be eliminated. Tooth should be

restored with well placed amalgams and composite resins.

Crown, bridges and other restorations requiring detailed occlusal

anatomy should not be placed until any adjacent, treatment has

been completed, because the occlusal relationship will inevitably

be changed by orthodontic tooth movement.

ADJUNCTIVE TREATMENT PROCEDURES

1. Uprighting posterior teeth

When planning molar uprighting, a number of inter-related

questions must be answered. The first is that, if the third molar is

present, whether both the second and third molar is present,

whether both the second and third molars should be uprighted.

For many patients, distal tipping of the third molars, places them

in such situations where plaque control is a problem or the molar

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is not in functional occlusion. In such situations, it is ideal to

extract the third molars and upright the second molars alone.

The second question is, whether to upright the tipped teeth

by distal crown tipping that would increases the space available

for a later pontic or by a mesial root movement, which would

maintain reduce or even close the edentulous span. This decision

is influenced by

Position of the opposing tooth and the desired occlusion

The anchorage available for such movements

Most importantly the contour of the bone in the edentulous

ridge. If extensive ridge resorption has occurred especially

in the B-L direction, mesial movement of a wide molar root

will occur very slowly and may lead to the development of

dehiscence on the buccal and lingual sides.

In general, distal crown tipping is preferred than mesial

root movement for uprighting molars.

The third question is whether slight extrusion of the tooth

is permissible or maintenance of the existing occlusal height is

required. Tipping the tooth distally generally extrudes it. If the

crown height is systemically reduced as uprighting proceeds, the

ultimate crown-root ratio is improved. Unless slight extrusion of

crown is acceptable, the patient should be considered to have

problems that require comprehensive treatment and treated

accordingly.

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Appliances for molar uprighting

Each appliance can be separated into an active and a

reactive (stabilizing or anchor) unit. To provide appropriable

anchorage, canine to canine should be included and linked by a

heavy statistically lingual arch. This arch decreases the buccal

displacement of anchor teeth. This is mandatory in the

mandibular arch and advisable in the maxillary arch.

Distal crown tipping with occlusal antagonist

Initial alignment 17 x 25 braided SS/17x25 A-NiTi

provided the wire can be placed in the brackets with permanent

distortion and the occlusal contacts are not too heavy, molar

uprighting will begin and a single wire may complete the

necessary uprighting.

From the placement of the wire, it is always necessary to

relieve occlusal contacts against the molar. Failure to relieve

may prevent it from uprighting and may cause excessive tooth

mobility.

If molar severely tipped, continuous wire that uprights the

molar will also tip the premolar. To avoid this sectional spring is

used where the anchor segment is stabilized with 19x25 SS and

an auxiliary spring is placed in the auxiliary tube. The uprighting

spring 17 x 25 TMA with a helical loop 17 x 25 SS with

helical loop decrease the force.

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The mesial arm of the spring should lie passively in the

vestibule and upon activation should hook over the a. wire in

stabilizing segment. It is important to see that there is sufficient

space for the arm to slide distally when the molar uprights.

As this method causes extrusion along with distal tipping, it

should be used only in situations where there is an occlusal

antagonist.

Uprighting without extrusion

If the molar has no antagonist, if extrusion is undesirable or

if the crown is to be maintained in the same position while the

roots are being brought forward an alternative uprighting spring

should be used.

Initial alignment flexible wire

Single T-loop sectional arch-wire 17 x 25 ss/19 x 25 TMA

is adapted to fit passively in anchor units and gabled at the T to

exert an uprighting force.

If the edentulous span is intended to be closed, the distal

end of the T-loop is pulled distally to open the loop by 1 – 2mm.

This produces a mesial force on the molar that counteracts the

distal crown tipping while the tooth uprights by mesial root

movement.

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Final positioning of molar and premolars

Once the uprighting of molars has been accomplished, it

often is desirable to increase the available space for the pontic.

This is done by using a relatively stiff base a wire (in a 0.022

slot, 18 mil round / 17 x 25 SS) and as open coil spring is placed,

which when comprised exerts a force of 100 gms, to move the

premolars mesially while continuing to tip the molar distally.

Potential problems in Molar Uprighting

Excessive mobility of teeth being moved may be because

increased force / failure to remove occlusal contacts. Care should

be taken to avoid excessive crown reduction, it may be helpful to

use a bite splint on the opposing arch.

In general, failure to upright the teeth usually results from

occlusal interferences rather than insufficient force.

Retention

After molar uprighting, the teeth are in an unstable position

until the fixed or removable appliances that provide long term

stability is used. Long delays is taking the final prosthesis should

be avoided. For nearly all patients, before placement of

prosthesis, an intermediate form of splinting is necessary to

maintain the position of the abutment teeth. Two methods of

intermediate splitting -

1. Extracoronal splinting

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19 x 25 SS or 21 x 25 TMA was designed to fit the brackets

passively will prevent any tooth movement. This type of

retention should not be used for long periods because orthodontic

appliances themselves make effective oral hygiene maintenance

difficult.

2. Intracoronal splinting

The preferred approach to intermediate splinting is an

intracoronal wire splinting – shallow cavities may be prepared in

the abutment teeth and a splint of 19 x 25 SS - intracoronally

with either amalgam or composite resins. As a general rule, a

fixed bridge can be placed within 6 weeks after the orthodontic

appliance is removed.

Forced eruption

Indications

Teeth with defects in the cervical third of the teeth

Teeth with one or two vertical periodontal defects

To obtain good accepts for endodontic and restorative

procedures or to reduce pocket depth it would be necessary to

perform crown lengthening. However, surgery causes sacrifice of

surrounding bone. Extruding the tooth orthodontically improves

endodontic access and also allows placement of crown margins

on sound tooth structure.

Factors considered in treatment planning

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Before beginning treatment, it is essential to have a

periapical radiograph to know the vertical extent of the defect,

the periodontal support, the root morphology and position. The

ideal morphology is a single tapering root. Flared or divergent

roots will increase the root proximity with extrusion. The

occlusion should also be examined to make sure that sufficient

space still exists in relation to the opposing arch, to permit the

placement of a satisfactory restoration.

A final consideration is the crown-root ratio at the end of

treatment, which should be 1:1 or better. The length of time

required for forced eruption depends on

The age of the patient

The distance the tooth has to be moved

Viability of the periodontal

Rate

In general extrusion can be as rapid as 1mm/week without

damage to the periodontal (so 3 – 6 weeks is sufficient for almost

any patient).

Technique

Since extrusion is the tooth movement that occurs most

readily and intrusion the movement that occurs least , sample

anchorage is usually available from adjacent teeth. The appliance

needs to be quite rigid ones the anchor teeth and flexible where it

attaches to the tooth to be extruded. This except contraindicates

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the use of a continuous a. wire which would produce the desired

extrusion but also lips the adjacent teeth toward the tooth being

extruded reducing the spaces.

Two appliances

T-loop 17 x 25 s.s / 19 x 25 Ti. Brackets should be

positioned as gingivally as possible on the tooth to be

extruded and incisally on the anchor teeth. The part of the

wire that gets attached to the tooth to be extruded should be

--- occlusal that the wire engaging the anchor segment. The

left of the T-loop is limited by the depth of the vestibule.

Heavy stabilizing arch wire (19 x 25 SS) bonded directly to

the facial surface of the adjacent teeth

A post and core with temporary crown and pin is placed on

the tooth to be extruded and an elastomeric module is used to

extrude the tooth. This appliance is simple, provides excellent

control of anchor teeth, but the control of the tooth being

extruded is not as precise it is with bonded brackets.

With either of these, the patient must be seen every 1 –

2weeks for occlusal reduction to control inflammation and to

monitor progress. After active tooth movement, the tooth should

be stabilized with a passive arch wire or by tying the pin to the

binded stabilizing wire. Stabilization allows proper remodeling

of the periodontal fibres and allows the bone to remodel that

discourages relapse. In general 3 – 6 weeks of stabilization

should be sufficient.

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ALIGNMENT OF TEETH

Indications

To improve access and permit placement of well adapted

and contoured restorations.

To permit placement of crowns and pontics

To establish good interproximal contacts, to provide better

occlusal loadings and minimize the possibility of occlusal

interferences.

To reposition closely approximated roots and to increase

the amount of inter-radicular bone.

Treatment planning

A diagnostic set-up will be very useful in planning

treatment for alignment problems. Study casts are duplicated and

the malaligned teeth are carefully cut from the model, crown

dimensions are modified if appropriate and the teeth are waxed

back onto the cast. This allows one to assess what tooth

movements, crown reshaping or pontic replacement would be

necessary to produce an esthetically pleasing functional

occlusion.

The length of time required to align teeth will vary

Age of the patient

The distance the teeth have to be moved

Cellular activity within the periodontal

As a general guideline, adjunctive tooth movement that

would take longer than 6 months should be avoided, since such

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patients almost certainly have a complicated malocclusion that

would be better handled with comprehensive orthodontic

treatment.

Technique

Alignment of crowded, rotated and displaced incisors

Interproximal stripping may be used to create space, within

limits established by the thickness of the enamel and the M.D

diameter of the teeth at gingival margins. Approximately ½mm of

enamel can be removed from either side of each tooth, giving a

maximum of 4mm additional space. In the mandibular arch the

smaller M-D diameter of mandibular incisors, reduces the amount

of interproximal stripping possible with producing unacceptable

root proximity. For this reason, crowding > 3 – 4mm in the

mandibular, anterior region nearly always indicates extraction

therapy.

Treatment of this type should never be undertaken with a

diagnostic set-up that is mandatory to be sure that the teeth will

fit satisfactorily.

A flexible arch wire usually 0.016 round NiTi is used to

align teeth. Round wires should be followed by rectangular wires

for the precise positioning of the roots. If the wire is not turned

gingivally at the distal end of the molar tubes, the teeth will flare

labially when they align, that is usually undesirable.

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Anterior diastema closure and space redistribution

Closure of anterior spaces is usually simple but often

requires permanent retention with a bonded lingual retainer,

fused crowns etc. For best esthetics, partial closure of more

incisor spacing and redistribution of the space of a central

diastema followed by composite build-ups often i.e. the treatment

of choice.

If the diastema is small or results form adjacent teeth being

tipped in opposite direction a removable application with

fingersprings may be used to close the space. A wire bend into

ideal arch-wire and involving only the anterior segment of the

arch is need. Initial alignment – 0.016 minimum followed by

0.016/0.018 SS – elastomeric modulus or till springs. Initially

the teeth tip, but the stiffness of the wire counteracts this effect

and results in bodily movement.

If the spacing is the result of abnormally small teeth in one

arch (i.e. tooth size discrepancy exists) it will be impossible to

close all the spaces while maintaining post occlusion.

Crossbite correction

If only one or two teeth are involved the cross-bite usually

results form displacement of crowded teeth or ectopic eruption.

If a group of teeth are involved, it is more likely that the cross-

bite is a skeletal problem and will not respond to limited

orthodontic treatment.

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If a cross-bite is due to displaced teeth and if the tooth

corrections required only tipping movements, then a removable

application may be used. However when using a removable

application, is the tooth tip labially or buccally there is a vertical

change in occlusal level – produces an apparent intrusion and a

reduction in overbite. This presents a problem during retention,

since a two overbite serves to retain the cross-bite correction.

In post segments cross-bites are frequently corrected using

“through the bite elastics”.

Separation of approximated teeth

Occasionally two teeth may exhibit close proximity. The

lack of inter-radicular space presents satisfactory restorative

procedures but also predisposes both teeth to rapid progression if

periodontal disease develops. If the roots of such teeth must be

separated, the necessary tooth movement can be achieved only

with fixed appliance because a force system that applied a

moment effective in moving roots should be used.

SPECIAL CONSIDERATIONS IN COMPREHENSIVE

TREATMENT OF ADULTS

Special considerations for the adults fall into 3 categories -

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Different motivations for seeking orthodontic treatment and

different psychological reactions to it

Heightened susceptibility to periodontal disease and the

possibility that active periodontal disease is one reason for

seeking orthodontic treatment in the first place.

A lack of growth, even the small amount of vertical growth

on which orthodontists can rely for patients in late

adolescence.

Motivation for adult treatment

A major motivation for orthodontic treatment of children

and adolescents is the parent’s desire for treatment. Adults, in

contrast, seek comprehensive treatment because they themselves

want something. That something, however, is not always clearly

expressed and in fact some adults save a remarkably elaborate

hidden set of motivations. It is important to explore why the

patient wants treatment to avoid setting up a situation in that the

patient’s expectation from treatment cannot be met. Orthodontic

treatment obviously cannot be relied upon to repair personal

relationship sure jobs and if the patient has such unrealistic

expectations, it is much better to deal with them sooner than

later.

A patient who seeks treatment primarily because he or she

wants to improve the appearance or function of the teeth

(internal motivation) is more likely to respond well

psychologically than a patient whose motivation is the urging of

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the others or the expected impact of treatment on others (external

motivation).

The typical adolescents passive acceptance of what is being

done is rarely found in adult patients, who want and expect a

considerable degree of explanation of what is happening and

why. In addition, adults as a rule are less tolerant of discomfort

and more likely to complain about pain after adjustments and

about difficulties in speech eating and tissue adaptation.

Periodontal and restorative needs as motivating factors

A very few patients may seek orthodontic treatment as an

attempt to improve periodontal considerations. Although

comprehensive orthodontic treatment cannot preclude the

possibility of periodontal disease ------- later it can be a useful

part of the treatment plan for a patient who already has

periodontal involvement.

TM pain / dysfunction as a reason for orthodontic treatment

This condition is a significant motivating factor for some

adults who consider orthodontic treatment. Orthodontic treatment

can sometimes help patients with TMD problems but cannot be

relied upon to correct them.

Patients with TMD symptoms can be divided into two

groups

Internal joint pathology including displacement or

destruction of the articular disc

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Symptoms primarily of muscle origin – caused by spasm

and fatigue of the muscles that position the jaw and head

It is unlikely that orthodontic treatment alone will be of

significant benefit to those who have myofascial pain /

dysfunction on the other hand, may benefit from improved

occlusal relationships.

Displacement of the disk can arise from a number of causes.

One possibility is trauma to the joint, damaging the ligaments

that oppose the action of lateral pterygoid. In this instance,

muscle contraction moves the disk toward as the mandibular

condyle translate forward on wide opening but the ligaments do

not restore the disk to its proper position when the jaw is closed.

The click and symptoms associated with it can be corrected

if occlusal splint is used to prevent the patient from closing

beyond the point at which displacement occurs.

Myofascial pain develops when the muscles are fatigued

and tend to go into spasm. To produce myofascial pain, the

patient must be clenching or grinding the teeth for many

hours/day, presumably as a response to stress. However, it takes

two factors to produce TMD symptoms from myofascial pain

An occlusal discrepancy

A patient who clenches or grinds the teeth excessively

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Three broad approaches to myofascial pain symptoms

should be considered

Reducing the amount of stress

Reducing the patients reaction to stress

Improving the occlusal relationships, thereby making it

harden for the patient to hurt himself/herself.

Periodontal aspects of adult treatment

Periodontal problems are rarely a major concern during

orthodontic treatment of children and adolescents, both because

periodontal disease usually does not arise at an early age and

because tissue resistance to imitation produced by orthodontic

appliances is higher in younger patients.

There is no contra-indication to treating adult patients who

have periodontal disease as long as the disease has been brought

under control.

Periodontal disease progression is episodic not continuous

and likely to affect some but not all areas within the same mouth.

At present, persistent bleeding on probing is the best indicator of

active and presumably prospective disease.

Minimum periodontal involvement

Any patient undergoing orthodontic treatment must take

extra care to clean the teeth but this is even more important for

adults. Bacterial plaque is the main etiologic factor in

periodontal breakdowns and plaque-induced gingivitis is the first

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slip in the disease process. In children and adolescents even if

ginigivitis develops in response to the presence of orthodontic

appliances, it almost --- extends into periodontitis. This cannot

be taken for granted in adults, no another low good this initial

periodontal condition.

This difficult area for orthodontic patients to clean is the

area of each tooth between the brackets and ginigival margin.

The periodontal evaluation of an adult patient must include

not only the response to periodontal probing but also the level

and condition of attached gingiva (the bacteriaized tissue

between the depth of periodontal probing and the beginning of

alveolar mucosa). Labial movement of incisors in some patients

can be followed by gingival recession and loss of attachment.

The risk is greatest when irregular teeth are aligned by

expanding the dental arch.

The present concept is that gingival recession occurs

secondarily to an alveolar bone dehiscence if overlying tissues

are stressed by tooth brush trauma, plaque induced inflammation

etc. Recent animal studies suggest that the thickness of the

gingival attachment rather than its surface qualities (keratinized

or mucosal) may be a major factor in whether recession occurs. It

has been recognized that the lower incisors in cases of

manidbular prognathism are at particular risk of recession and

thin gingival tissue probably is the reason. Even the protective

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effect of a gingival graft may be due more to the greater gingival

thickness than a wider zone of attached tissue.

Moderate periodontal involvement

Disease control

Before orthodontic treatment is attempted for patients who

have moderate pre-existing periodontal problems dental and

periodontal disease must be brought under control.

Preliminary periodontal therapy can include all aspects of

periodontal treatment except osseous surgery. It is important to

remove all calculus and other irritants from periodontal pockets

before any tooth movement is attempted. Osseous surgeries are

best deferred until find occlusal relationship has been

established.

Disease control also requires endodontic treatemtn of any

pulpally involved teeth. There is no contraindication to

orthodontic movement of an endodontically treated tooth, so root

canal therapy before orthodontics will cause no problems.

Attempting to move a pulpally involved tooth, however, is likely

to flare up the periapical condition.

The general guideline is that temporary restorations should

be placed to control caries, with definite restorative dentistry

delayed until after the orthodontic phase of treatment.

Periodontal maintenance

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Because the margins of the bands make periodontal

maintenance more difficult it is always better to use a fully

bonded appliance for periodontally involved adults. Steel

ligatures rather than elastomeric rings to retain orthodontic a.

wires also are preferred for periodontally involved patients,

because patients with l-rings have higher levels of

microorganisms in gingival plaque.

Periodontal maintenance therapy at 2 – 4 intervals is the

usual plan.

Severe periodontal involvement

Treatment is modified in two ways

Periodontal maintenance should be scheduled at more

frequent intervals with the patient being seen as frequently

for periodontal maintenance as for orthodontic application

adjustments (i.e. every 3 – 4 weeks)

Orthodontic goals and mechanics must be modified to keep

orthodontic forces to an absolute minimum, because the

reduced area of the periodontal means higher pressure in

the periodontal from any force.

Orthodontic appliance therapy

The orthodontic mechanotherapy often must be modified to

decrease the force levels. It must be kept in mind that the

biologic response is determined by pressure in the periodontal

not by the force against the tooth.

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For orthodontic patients with jaw discrepancies, there are

always with broad categories of the

Correction through growth

Correction through orthodontic camouflage

Surgical correction of the jaw discrepancy

Space closure

It is unrealistic to expect an adult to wear a head gear on

the nearly continuous basis necessary to produce efficient

tooth movement to slide teeth along an arch wire during

closure of extraction space. In addition it may be necessary

to use two-step space closure with frictionless mechanics to

reduce the strain on anchorage and keep forces as light as

possible.

Old extraction sites in adults pose mechanical and biologic

challenge in orthodontic treatment. In a young patient the

extraction site is recent and usually can be closed with any

particular problems. In an adult, closure of an extraction

site many years after the tooth is lost, is neither straight

forward and not predictable.

After several years, resorption results in a decrease in the

vertical height of the bone, but more importantly remodeling

produces a buccolingual narrowing of the alveolar process as

well. Closure of such an extraction space will sequence the

remodeling of the buccal and lingual cortical plates. The cortical

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plates respond to orthodontic force, but the reaction is much

slower. Typically an old extraction site can be closed part way,

but it is difficult to close it completely.

Finishing and retention procedures

Combined surgical and orthodontic treatment

For patients whose orthodontic problems are so severe that

neither growth modification nor camouflage offers a solution,

surgical realignment of the jaws or dentoalveolar segments is the

only possible treatment. Surgery is not the substitute for

orthodontics in these patients.

The indication for surgery obviously is a problem too

severe for orthodontics alone.

Types of surgical treatment

I. Correction of anteroposterior relationships

Both the maxillary and mandibular can be moved forward

or backward to correct a jaw discrepancy. The mandibular can be

moved anterior or posterior with relative ease. Extreme

advancement can create stability problems associated with the

neuromuscular adaptation and stretch of the investing soft tissue.

The maxilla can be moved forward if bone grafts are interposed

posteriorly to help stabilize the mucoperiosteum. Posterior

movement of the entire maxilla is not easily achieved because

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other skeletal components that normally support the maxilla

interfere with moving it back.

The greatest disadvantages of BSSO are altered sensation

and a decreased inter-incisal opening post-operatively. Altered

sensation in lingual nerve distribution is transient. Paresthesia

over the distribution of the inferior alveolar nerve is usually

present after surgery that persists for 2 – 6 months, but 20 – 25%

of patients have retained the paraesthesia.

Advancement of only the teeth and alveolar process is also

possible. This approach is indicated for adults with adequate chin

projection but distal placement of the dentoalveolar on the

mandibular corpus.

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