finishing stage by almuzian

University of Glasgow

Finishing stage

.

Mohammed Almuzian

1/1/2013

.

Table of ContentsKey papers........................................................................................................................................3

A. Aesthetic aims..........................................................................................................................3

a) Extra oral aims:........................................................................................................................3

1. Static aims............................................................................................................................3

2. Dynamic smile aims.............................................................................................................3

b) Intraoral aims...........................................................................................................................3

I. Tooth Size Discrepancies.....................................................................................................3

II. Gingival Levels....................................................................................................................4

Four characteristics contribute to ideal gingival form......................................................................4

To make the correct decision, it is necessary to evaluate 3 criteria.................................................4

III. Gingival Form..................................................................................................................5

I. Levelled Marginal Ridges....................................................................................................5

II. Correct first order bend........................................................................................................5

According to the American Board of Orthodontics (ABO, 1998) (Kokich 2003)...........................5

One of the methods to correct rotation is.........................................................................................5

III. Correct second order bend: this can be done by wire bending or rebonding and correcting root parallelism................................................................................................................6

IV. Correct third order bend:..................................................................................................6

The importance of correct teeth inclination are:..............................................................................6

The errors in the third order bend could be assessed by assessing:.................................................7

V. Alter the vertical relationship of incisors as a finishing procedure, either correcting moderately excessive overbite or closing a mild anterior open bite................................................8

Normal OB is essential for:..............................................................................................................8

VI. Correct the OJ...................................................................................................................9

Normal OB is essential for:..............................................................................................................9

A slight increase in the OJ is acceptable when................................................................................9

VII. Correct the ML relationship.............................................................................................9

VIII. Buccal Root Torque of Premolars and Molars...............................................................10

IX. “Settling” of the teeth.....................................................................................................10

Feature of optimal interdigitation:..................................................................................................10

Methods for Settling the Teeth.......................................................................................................10

Indication of positioner..................................................................................................................11

Mohammed Almuzian, University of GlasgowPage 1

Some variations to this general settling technique are as follows:.................................................12

X. Control of Rebound and Posturing.....................................................................................12

D. Periodontal aims....................................................................................................................13

I. Root Angulation.................................................................................................................13

II. Bone level..........................................................................................................................14

Special Finishing Procedures to Avoid Relapse.............................................................................14

Relapse after orthodontic treatment has two major causes:...........................................................14

Surgery to section the supracrestal elastic fibres............................................................................15

The AB for grading system for SM involve 1998..........................................................................16


Finishing stage

Key papers

Kokich VG (2003)

McLaughlin RP and Bennett JC (1991)

McLaughlin RP and Bennett JC (2003)

Poling 1999

Aims of the finishing stage

A. Aesthetic aims

a) Extra oral aims:

1. Static aims It mainly involved correct position of U in relation to APog plane and L incisors in relation to

APog plane and MP.

2. Dynamic smile aims

b) Intraoral aims

I. Tooth Size Discrepancies• Tooth size discrepancy must be taken into account when treatment is planned initially, but

many of the steps to deal with these problems are taken in the finishing stage of treatment.

• As a general guideline, a 2 mm tooth size discrepancy noted from Bolton analysis is the

threshold for clinical significance (Othman 2007)

• Reduction of interproximal enamel (stripping) is the usual strategy to compensate for

discrepancies caused by excess tooth size.

• When the problem is tooth size deficiency, it is necessary to leave space between some teeth,

which may or may not ultimately be closed by restorations. In case of a diminutive laterals, 2/3 of

the space should be distal to lateral and 1/3 mesial. (for best aesthetic, Kokich 2003)

• More generalized small deficiencies can be masked by altering incisor position in any of several

ways. To a limited extent, torque of the upper incisors can be used to compensate: leaving the

incisors slightly more upright makes them take up less room relative to the lower arch and can be

used to mask large upper incisors, while slightly excessive torque can partially compensate for


small upper incisors. These adjustments require third-order bends in the finishing archwires. It is

also possible to compensate by slightly tipping teeth or by finishing the orthodontic treatment

with mildly excessive overbite or overjet, depending on the individual circumstances.

• Most of the cases have TSD with ULS smaller than LLS, so MBT used a total of 40 degree tip in

all upper ULS while LLS have only 6, the difference is 34 which means that ULS occupy more

space than LLS.

II. Gingival Levels

Four characteristics contribute to ideal gingival form. 1. First, the gingival margins of the two central incisors should be at the same level.

2. Second, the gingival margins of the central incisors should be positioned more apically

than the lateral incisors and should be at the same level as the canines.

3. Third, the contour of the labial gingival margins should mimic the cementoenamel

junctions of the teeth.

4. Last, there should be a papilla between each tooth

• The cause of These discrepancies could be Abrasion of the incisal edges delayed migration of

the gingival margins.

• The proper solution for the problem: orthodontic movement to reposition the gingival margins

or surgical correction of gingival margin discrepancies.

To make the correct decision, it is necessary to evaluate 3 criteria. 1. First of all, the relationship between the gingival margin of the maxillary central incisors

and the patient’s lip line should be assessed when the patient smiles. If a gingival margin

discrepancy is present, but the patient’s lip does not move upward to expose the discrepancy, it

does not require correction. If a gingival margin discrepancy is apparent, the next step is to

evaluate the labial sulcular depth over the two central incisors.

2. If the shorter tooth has a deeper sulcus, excisional gingivectomy may be appropriate to

move the gingival margin of the shorter tooth apically. However, if the sulcular depths of the

short and long incisors are equivalent, gingival surgery will not help. So orthodontic extrution

with selective grinbding or intrusion with build up will help.

3. Torque of the tooth


4. Vertical tooth discrepancy

5. The third step is to determine if the incisal edges have been abraded. This is best

appreciated by evaluating the teeth from an incisal perspective. If one incisal edge is thicker

labiolingually than the adjacent tooth, this may indicate that it has been abraded, and the tooth

has overerupted. The best method of correcting the gingival margin discrepancy is to intrude the

short central incisor

III. Gingival Form1. The presence of a papilla between the maxillary central incisors is a key aesthetic factor in

any individual. Occasionally, adults will have open gingival embrasures or black triangles

between their central incisors. These unsightly areas are often difficult to resolve with periodontal

therapy.

2. This space is usually due to one of three causes: tooth shape (corrected by IPS or

composite restoration), root angulation (corrected by uprighting), or periodontal bone loss

(corrected by orthodontic extrusion to relocate the papillae)

B. Functional aims

To provide a mutually protected occlusion.

C. Occlusal aims like

I. Levelled Marginal Ridges.

II. Correct first order bend

According to the American Board of Orthodontics (ABO, 1998) (Kokich 2003).1. In the mandibular anterior sextant, the incisal edges of the mandibular incisors and canines are

used to establish proper alignment.

2. While in the maxillary anterior region, the lingual surfaces of the maxillary incisors and canines

are used to assess proper alignment. This surface was choosing because it is the functioning

surface of the maxillary anterior teeth, and if these surfaces are aligned properly, the maxillary

incisors appear to be in their proper aesthetic relationship.

3. In the mandibular posterior sextants, the buccal cusps of the mandibular premolars and molars are

used to determine proper tooth position.


4. In the maxillary posterior sextants, the central grooves of the maxillary premolars and molars are

used to assess proper alignment.

Methods to correct rotation At initial stages by exaggerated bracket positioning, partial ligation of aligning AW, piggy back, sectional cantilever spring (Whip), couple moment using elastic, TPA or even HG, open coil spring, or surgical replantation or luxation but with high risk of ankylosis.

For final deroataion and over correction use:

Steiner rotation elastic

Repositioning the bracket

Wire bending

Abrahamian techniques: This involves placing a figure of eight

elastomeric ligature over the tie wing which it is desired to move

away from the archwire and tying in the other tie wing with a

steel ligature.

III. Correct second order bend: this can be done by wire bending or rebonding and correcting root parallelism• In contemporary edgewise practice, it has been almost totally abandoned in favor of angulated

bracket slots that produce proper root paralleling when a flexible full-dimension rectangular wire

is placed. A root-paralleling moment is a crown-separating moment in edgewise technique just as

it is in Begg or any other technique. It is important to remember this effect. Either the teeth must

be tied together or the entire archwire must be tied back against the molars to prevent spaces

from opening. Not only extraction sites but also maxillary incisors must be protected against this

complication. Also tying the maxillary incisors together, which can be done conveniently with a

segment of elastomeric chain from the mesial bracket of one upper lateral incisor across to the

mesial bracket of the other, is necessary during finishing.

• In the Begg technique, the moments necessary for root positioning were generated by adding

auxiliary springs together across extraction sites.

• In the modified Begg technique using the Tip-Edge appliance, root paralleling is accomplished

with uprighting springs, very much as it was with traditional Begg treatment. The rectangular


wire is used primarily for torque (faciolingual root movement), not the mesiodistal root

movement needed for root paralleling after teeth were allowed to tip during space closure.

IV. Correct third order bend: The overall inclination of the maxillary anterior teeth is best evaluated with a lateral

cephalometric radiograph.

The importance of correct teeth inclination are:a) Aesthetic purpose

b) Functional purpose

c) Stability

d) PD health

e) Increase the success of any adjunctive restorative procedure after orthodontic. Eg in

missing lateral, the increased torque of adjacenet teeth might reduce the intra-radicular space for

implant (wagon wheel effect) as well as making the retention of RBB poor.

The errors in the third order bend could be assessed by assessing: A. The incisal edges of the anterior teeth. If a discrepancy exists in anterior inclination, the

incisal edges of the anterior teeth will not be in the same plane. Even in-setting or offsetting the

incisors relative to one another will not correct the problem.

B. A second criterion to evaluate is the clinical crown length of contralateral teeth. If

contralateral teeth are different lengths, the cause could be relative discrepancies in the

inclination of contralateral incisors.

C. The third criterion to evaluate is root prominence.

D. The fourth and final criterion is best evaluated from an occlusal perspective. When the

incisors are viewed from an occlusal perspective, the cingulum of an improperly inclined incisor

is more prominent or more visible.

In the Begg technique, the incisors are deliberately tipped back during the second stage of

treatment, and lingual root torque is a routine part of the third stage of treatment. This is

accomplished with an auxiliary appliance that fits over the main or base archwire. The torquing

auxiliary is a “piggyback arch” that contacts the labial surface of the incisors near the gingival

margin, creating the necessary couple with a moment arm of 12/1.


These piggyback torquing arches can be used in edgewise technique in the same. Although they

come in a number of designs, the basic principle is the same: the auxiliary arch, bent into a tight

circle initially, exerts a force against the roots of the teeth as it is partially straightened out to

normal arch form. A torquing force to move the roots lingually is also, of course, a force to move

the crowns labially. For that reason, Class II elastics are likely to be necessary when active

lingual root torque is needed during the final stage of Class II treatment.

Other method same like the above but include bending a loops parallel to occlusal plane in 016

or 014ss. This has been described by Sandler in the Art Meets Science course.

Another method is to use the built in torque and express it with full dimension AW or adding

torque to the wire or sometime inverting the brackets.

The Burstone torquing arch. It can be particularly helpful in patients with Class II, division 2

malocclusion whose maxillary central incisors are severely tipped lingually and require a long

distance of torquing movement, while the lateral incisors need little if any torque.

V. Alter the vertical relationship of incisors as a finishing procedure, either correcting moderately excessive overbite or closing a mild anterior open bite.

Normal OB is essential for:• Aesthetic

• Stability of treatment


• Normal PD health support

• The amount of overbite has some effect on anterior restorative dentistry, especially the

placement of a resin-bonded anterior bridge.

• Functioning by incising the food: Normal OB is essential for mutually protected occlusion. The

purpose of overbite is to permit the anterior teeth to function or incise food in protrusive jaw

position, while the posterior teeth are out of occlusal contact. Therefore, the amount of overbite

necessary to accomplish the task of disoccluding the posterior teeth is actually determined by the

length of the cusps of the premolars and canines. Some premolars have shallow cuspal anatomy,

and therefore the overbite required to disclude this type of tooth anatomy would be small,

perhaps one to two millimeters. However, some patients have long cusps on the maxillary and

mandibular premolars and canines. In this situation the anterior overbite must be greater, perhaps

3 to 4 mm, to disclude the posterior teeth. If the overbite is not deep enough, then the patient

would only contact the posterior teeth in protrusive jaw position, making it impossible to incise

food.

a) Anterior deep Bite

• Before attempting to correct excess overbite at the finishing stage of treatment, it is important

to carefully assess why the problem exists and particularly to evaluate two things: (1) the vertical

relationship between the maxillary lip and maxillary incisors and (2) anterior face height.

VI. Correct the OJ

Normal OJ is essential for: Aesthetic

Stability

Function

A slight increase in the OJ is acceptable when• Treatment is compromised

• RBB will be used

• Abraded or eroded teeth that will be resored and the restorative need some clearance

VII. Correct the ML relationship• The midline often can be corrected by using asymmetric Class II (or Class III) elastic force.


• It is more effective to use Class II or Class III elastics bilaterally with heavier force on one side

than to place a unilateral elastic.

• It is also possible to combine a Class II or Class III elastic on one side with diagonal elastic

anteriorly to bring the midlines together. (a “parallel elastics” arrangement),

• An important consideration in dealing with midline discrepancies is the possibility of a

mandibular shift on occlusion.

VIII. Buccal Root Torque of Premolars and Molars

IX. “Settling” of the teeth The final step of bringing the teeth into occlusion, appropriately called “settling” of the teeth, has

been needed.

Feature of optimal interdigitation: 1. The buccal cusps of the mandibular premolars and molars should contact the fossae or

marginal ridges of the maxillary molars and premolars.

2. The lingual cusps of the maxillary premolars and molars should be in contact with the

marginal ridges or fossae of the mandibular premolars and molars.

3. The exceptions are the lingual cusps of the maxillary first premolars, which may not

establish contact with the mandibular first premolar because of the lack of an adequate occlusal

table. In addition, the disto-palatal cusps of the maxillary first and second molars may not contact

the mandibular teeth if the cusps are diminutive in size or in situations where posterior teeth have

worn significantly and will be restored with full crowns after orthodontic treatment


Methods for Settling the Teeth1. By replacing the rectangular archwires at the very end of treatment with light round arches

that provide some freedom for movement of the teeth (16 mil in the 18-slot appliance, 16 or 18

mil in the 22-slot appliance) and using light vertical elastics to bring the teeth together. It was the

original method for settling, recommended by Tweed in the 1940s. The difficulty with undersized

round wires at the end of treatment is that some freedom of movement for settling of posterior

teeth is desired, but precise control of anterior teeth is lost as well.

2. Using laced posterior vertical elastics after removing the posterior segments of the

archwires. It should not be used in patients who had major rotations or posterior crossbite. For the

majority of patients who had well-aligned posterior teeth from the beginning, however, this is a

remarkably simple and effective way to settle the teeth into their final occlusion. These elastics

should not remain in place for more than 2 weeks, and 1 week usually is enough to accomplish

the desired settling.

3. By using a tooth positioner after the bands and brackets have been removed.

a) A positioner is most effective if it is placed immediately on removal of the fixed

orthodontic appliance. Normally, it is fabricated by removing the archwires 4 to 6 weeks before

the planned removal of the appliance, taking impressions of the teeth and a registration of

occlusal relationships, and then resetting the teeth in the laboratory, incorporating the minor

changes in position of each tooth necessary to produce appropriate settling

b) Using a facebow transfer to mount the casts for the positioner setup to fabricate a

“gnathologic positioner” does not seem to be necessary for patients with normal jaw

relationships. All erupted teeth should be included in the positioner to prevent super eruption. As

part of the laboratory procedure, bands and brackets are trimmed away, and any band space is

closed.

c) This indirect approach allows individual tooth positions to be adjusted with considerable

precision, bringing each tooth into the desired final relationship.

d) The positioning device is then fabricated by forming an elastic material (formerly rubber,

now usually polyurethane) around the repositioned and articulated casts

e) Asking the patient to wear it as nearly full time as possible for the first 2 days. After that, it

can be worn on the usual night-plus-4 hours schedule. The patient is advised to wear the

appliance and practice repeated cycles of clenching then relaxation to encourage the desired tooth

movements.

f) As a general rule, a tooth positioner in a cooperative patient will produce any changes it is

capable of within 2 to 3 weeks


g) it is serving as a retainer rather than a finishing device—and positioners, even gnathologic

positioners, are not good retainers

Indication of positioner

1. As a retainer

2. For patients who have shown excellent cooperation

3. Provide further minor correction following deboned and thus "guide" the settling of the

occlusion.

4. They were particularly beneficial at the end of Begg treatment in which stage III (the

finishing phase) is difficult.

5. They may also be useful in instances when the desired finish was not achieved or the case

had to be discontinued early.

6. For patients with persistent anterior or posterior tongue habits. A properly constructed

positioner can have a bite-closing effect.

7. It is not indicated in deep bite cases

Some variations to this general settling technique are as follows:

1. If cuspids were labially displaced in the upper arch, the sectional wire in the upper anterior

segment can be extended to the cuspids to hold them in position.

2. If diastemas were present in the upper and lower anterior segments, these areas should be tied

together lightly with elastic thread or ligature wires

3. If teeth have been extracted, figure-8 ligature wires should be placed across the extraction sites

to hold them closed.

4. If palatal expansion was carried out, a small removable palatal plate, with .018 wires extending

inter-proximally in the gingival areas, can be used to maintain expansion during the settling

phase

5. When finishing moderate to severe Class 11/1 malocclusions, it is not wise to use a small

sectional wire for the upper anterior segment, because some return of the overjet can be expected.

In this situation, a full upper .014 archwire can be used in settling and this wire can be bent back

behind the most distal molars. This controls the overjet, but inhibits settling of the posterior teeth

somewhat. Archwire bends may therefore be placed where individual teeth need to settle.


6. If it is intended that settling may take longer than approximately 6 weeks, it is beneficial to leave

the lower rectangular steel wire in position during this extended settling phase. This will help to

maintain lower arch form.

7. An example of this might be a difficult posterior open bite that will require a more extended period

of time for settling. When it is anticipated that only 4 to 6 weeks of treatment is remaining, a

normal lower .014 steel or .016 heat-activated wire can be placed.

X. Control of Rebound and Posturing• After Class II or Class III correction, particularly if interarch elastics have been used, the teeth

tend to rebound back toward their initial position despite the presence of rectangular archwires.

Because of this, it is important to slightly overcorrect the occlusal relationships. In a typical Class

II anterior deep bite patient, the teeth should be taken to an end-to-end incisor relationship, with

both overjet and overbite totally eliminated, before the headgear or elastic forces are

discontinued. This provides some latitude for the teeth to rebound before final settling is

accomplished.

• Sometimes when Class II elastics are used, patients begin to posture the mandible forward so

that the occlusion looks more corrected than it really is and if the appliances are removed at that

point, they are likely to slip back toward a Class II molar relationship and increased overjet. This

should not be confused with rebound, which is due only to tooth movement.

• Rebound is a 1 to 2 mm phenomenon; posturing can lead to 4 to 5 mm relapse, and obviously it

is important to detect it and continue treatment to a true correction.

These considerations lead to the guidelines for finishing treatment when interarch elastics have

been used:

• When an appropriate degree of overcorrection has been achieved, the force used with the

elastics should be decreased while the light elastics are continued full time for another

appointment interval;

• At that point, interarch elastics should be discontinued, 4 to 8 weeks before the orthodontic

appliances are to be removed, so that changes due to rebound or posturing can be observed. It is

better to tell the patient that he or she is getting a vacation from the elastics and that some further

elastic wear may be necessary if changes are observed, rather than saying that elastics are no

longer needed. If changes do occur, that makes it easier for patients to accept that the vacation is

over and another period of elastics is needed.


• If the occlusion is stable, as a final step in treatment, the teeth should be brought into a solid

occlusal relationship without heavy archwires present, using one of the methods described above.

D. Periodontal aims

I. Root Angulation• During finishing, orthodontists typically use a panoramic radiograph to determine if the roots of

the teeth are oriented properly relative to adjacent roots.

• In theory, if the roots of adjacent teeth are perpendicular to the occlusal plane, and parallel with

one another, then there will be sufficient bone between the roots of teeth.

Some important aspects of root parallelism must be discussed. Kokich 2003

• First of all, is a panoramic radiograph an accurate depiction of the root angulations of adjacent

teeth? Researchers have evalucated this questions and conclude that there are distortions

produced with a panoramic radiograph, especially in the maxillary and mandibular canine/first

premolar regions, where the archform curves. However, recognizing these minor inadequacies,

the panoramic radiograph is probably a reasonable screening tool in general. In specific

situations, it is beneficial to take supplemental periapical radiographs to accurately assess root

angulations and root proximity.

• A second aspect that requires discussion is whether close root proximity will actually cause

detrimental long-term effects. This question was investigated, and the authors concluded that

close root proximity did not produce detrimental effects in their sample. These authors cautioned

that their sample was relatively young, and was not a sample of patients that were susceptible to

periodontal disease. Whether or not close root proximity enhances interproximal bone destruction

in a sample of periodontal patients is not known. However, close root proximity after orthodontic

treatment will cause problems in certain restorative patients.

II. Bone level• In the adolescent, the orthodontist should align the incisal edges of non-worn, non-restored

anterior teeth and the marginal ridges of nonworn, nonrestored posterior teeth, and in this way

the cementoenamel junctions and interproximal bone will be at the appropriate level.

• In adult patients with prior periodontal disease and interproximal bone loss, the incisal edges or

marginal ridges of the teeth are not reasonable guides for vertical positioning of adjacent teeth. If

the patient has horizontal bone loss in the maxillary or mandibular anterior regions , it is best to


align the bone levels rather than adjacent teeth. In these situations, the orthodontist must

equilibrate the incisal edges as the bone is leveled to establish the correct incisal edge position,

occlusion, and crown-to-root relationships.

Special Finishing Procedures to Avoid Relapse

Relapse after orthodontic treatment has two major causes:I. Continued growth by the patient in an unfavourable pattern: This need an “active retention”

takes one of two forms.

One possibility is to continue extraoral force in conjunction with orthodontic retainers (high-

pull headgear at night, for instance, in a patient with a Class II open bite growth pattern).

The other, which often is more acceptable to the patient, is to use a functional appliance rather

than a conventional retainer after the completion of fixed appliance therapy.

II. Tissue rebound after the release of orthodontic force. There are two ways to deal with this

phenomenon:

• Overtreatment, so that any rebound will only bring the teeth back to their proper position,

• Adjunctive periodontal surgery to reduce rebound from elastic fibres in the gingiva.

Surgery to section the supracrestal elastic fibres

It can be carried out by either of two approaches.

1. The first method, originally developed by Edwards is called circumferential supracrestal

fibrotomy (CSF). After infiltration with a local anesthetic, the procedure consists of inserting the

sharp point of a fine blade into the gingival sulcus down to the crest of alveolar bone. Cuts are

made interproximally on each side of a rotated tooth and along the labial and lingual gingival

margins unless, as is often the case, the labial or lingual gingiva is quite thin, in which case this

part of the circumferential cut is omitted. No periodontal pack is necessary, and there is only

minor discomfort after the procedure.

2. An alternative method is papilla-dividing procedure to make an incision in the centre of

each gingival papilla, sparing the margin but separating the papilla from just below the margin to

1 to 2 mm below the height of the bone buccally and lingually. See beow.


• This modification is said to reduce the possibility that the height of the gingival attachment will

be reduced after the surgery, and it is particularly indicated for esthetically sensitive areas (e.g.,

the maxillary incisor region). Nevertheless, there is little if any risk of gingival recession with the

original CSF procedure unless cuts are made across thin labial or lingual tissues. From the point

of view of improved stability after orthodontic treatment, the surgical procedures appear to be

equivalent.

• It is easier to do the CSF procedure after the orthodontic appliances have been removed,

although it can be carried out with appliances in place. An advantage of the papilla-dividing

procedure may be that it is easier to perform with the orthodontic appliance still in place.

• Neither the CSF nor the papilla-dividing procedure should be done until malaligned teeth have

been corrected and held in their new position for several months. This means that either the

surgery should be done a few weeks before removal of the orthodontic appliance or, if it is

performed at the same time the appliance is removed, a retainer must be inserted almost

immediately.


The AB for grading system for SM involve 1998

1. Aligned incisor edges

2. Aligned incisors labial surface

3. Buccal cusp of all teeth aligned

4. Central fossae aligned

5. Marginal ridge levelled

6. Correct torque

7. Good interdigitation

8. Canine and MR class I

9. Correct OJ and OB

10. Tight contact

11. OPT show parallel roots


finishing stage by almuzian

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