molar distalization by almuzian

University of Glasgow

2013

Molar Distalization

Dr. Mohammed Almuzian

Contents Definitions

Indications for Molar Distalization

Indications for Arch lengthening

Limitations & Contraindications

Amount of Distalization

Techniques of distalization

A.Mini-Distalisation techniques

B. Macro-Distalisation techniques

1. Compliance Appliance

Lip bumper

Removable Functional Appliances

Headgear (HG)

Upper Removable Appliance

Nudger appliance and HG combination:

En mass removable appliance

Molar Distalising Bow

Class II Mechanics (CLII elastic with sliding jigs):

2. Non-compliance CLII correctors

The Herbst appliance

Mohammed Almuzian, University of Glasgow, 2013 1

History

Design

Advantages

Disadvantages

Effects of the Herbst Appliance

Indications

Contra-indications

Jasper Jumper

Effects of the Jasper Jumper

Indications

Contra-indications

The Adjustable Bite Corrector™ (twin force)

The Eureka Spring™

Saif Springs

Requirements

The Mandibular Anterior Repositioning Appliance (MARA)

The AdvanSync appliance

History

Design

Fixed twin block


History

Advantages

Disadvantages

Intra-maxillary Appliance

Pendulum Appliance

Evidences

Retention after pendulum

Jones Jig™ and Lokar Distalizing Appliance

Distal Jet

Nance Arch and Coil Springs

Repelling Magnets

Goshgarian appliance

Implant

Conclusion

Retention after molar distalization


Molar Distalization & arch lengthening

Definitions

Arch lengthening: Increasing the arch length using distal movement of

posterior teeth (molar distalization) or proclination of incisors. Any change

in arch form is likely to relapse so lengthening must be kept to a minimum

Molar Distalization: Orthodontic mechanics that aim to move the buccal

segment posteriorly in order to provide space for orthodontic purposes. It

is considered a method of arch lengthening.

Indications for Molar Distalization

1. Space provision in order to:

Correct up to 1/2 unit Class II molar relationship

Relieve mild increased in the overjet (Felton et al., 1987).

Provide extra space in severe crowding cases in which extractions fail to

provide sufficient space (Chung, 2008).

Treatment of midline deviation problems (Holmes, 1989).

2. Interceptive applications:

To provide space for spontaneous eruption of ectopic canines. This has been

shown to have a success rate of 80% compared to 50% in control group

(Leonardi, 2004).

To regain a lost space due to mesial migration of molars in premolar

crowding cases (Kennedy, 1987).


Uprighting of upper first molars when they are impacted against upper

deciduous second molars (Kurol & Bjerklin, 1984, Kennedy & Turley,

1987)

Indications for Arch lengthening

It includes the above indications for Indications for Molar Distalization in

addition to the followings:

1. Correction of incisal relationship in CI III case by proclination of

upper incisors

2. Correction of retroclined mand incisors in class II D2 cases with

mandibular incisors trapped behind upper incisors, this will aim in

providing space for crowded teeth as well as reduction of OJ and OB.

3. Correction of retroclined mand incisors in class II D1 cases with

mandibular incisors trapped in palate, this will aim in providing space for

crowded teeth as well as reduction of OJ and OB.

Limitations & Contraindications

1. Protrusive profiles, increased overjet or proclined incisors since most of

the distalisation techniques result in loss of anchorage in a form of incisor

proclination which might worse the already proclined incisors and the

overjet.

2. Thin labial bone and gingivae: For the same reason mentioned above, it is

recommended to avoid distalisation in cases with thin labial bone and

gingivae due to the high risk of gum recession and dehiscence associated

with the resultant incisor proclination (Aziz 2011, Melsen & Allais, 2005)


3. High Frankfurt mandibular plane angles & anterior open bites since the

majority of distalisation methods are extrusive in nature and would drive

the molars posteriorly resulting in a possibly wedging effect that open the

occlusion.

4. Significant crowding (more than 6 mm) since the maximum amount of

space regaining by molar distalization is 2 - 2.5mm (Atherton et al, 2002)

5. Posterior crossbite since the distalised molars would sit in the narrow

relationship with the opposing dentition due to distal movement of the

molar toward the wide part of the dental arch. The midpalatal jackscrew is

activated twice a week to create this expansion in the molar region.

6. Buccally flared molars since the force applied buccal to centre of rotation

causing buccal tipping. Other reason might be that the cortical bone of

these teeth is less resistant than lingual bone which favour the buccal

tipping. This might compromise the overbite and cause posterior rotation

of the mandible. However, the distal jet appliance apply its force from

palatal side and close to the centre of rotation, so it is claimed to be better

in this issue.

7. Rotation and tipping: As the molar is tipped distally, it has a tendency to

rotate distopalatally. This is thought to be due to the nature of the cortical

bone surrounding these teeth; this can be compensated for somewhat by

placing approximately 30 degrees of distal rotation in the terminal legs of

the Pendulum springs. (Hilgers, 1992)

8. Shallow palatal vault especially if the intraoral appliances are used which

rely mainly on the palatal bone anchorage in its action.


Amount of Distalization

1. Atherton et al (2002) in their systematic review came to the conclusion that

the most distal movement of the molars that could be achieved was in the

range of 2 - 2.5mm.

2. Melsen and Dalstra (2003) in their retrospective study found that the total

distal movement of the molars in patients who wore cervical head-gear for

an 8-month period did not differ from that of an untreated group when re-

evaluated 7 years later.

Timing

Karlsson 2008, concluded that the best time to move maxillary first molars distally is before eruption of the second molars because:

More space can be gained There is less anchorage loss Less time consumed Better patient compliance

Techniques of distalization

A. Mini-Distalisation techniques

1. Brass wire ligature, elastomeric separators & steel spring clip separators all

act by disimpacting the tooth if it is mesially impacted against other and

this would aid in distalising the tooth and upright it for better eruption

(McDonald & Avery, 1994).

2. Halterman appliance (transpalatal arch on second deciduous

molars with attached distal spring to upright the molars)

(Roberts, 1986).


3. Humphrey appliance (Nance appliance with a welded finger spring to the

deciduous molar bands to distalise the permanent

molars) (Roberts, 1986)

B. Macro-Distalisation techniques

1. Compliance Appliance

I. Lip bumper: It mainly consists of a thick round stainless steel wire that fit

in the headgear tube of the molar band and stays away from the labial

surface of the incisor by the effect of the loop mesial to the entrance to the

molar tube. The acrylic pad is embedded in the anterior part of the wire

and act to actively displace the lip forward. The reciprocal force of the

displaced lip will be transferred to the molars via the heavy wire and result

in molar uprighting and distalisation. As a consequence of the change in

the soft tissue equilibrium by the lip pumper, there is a proclination in the

incisors under the effect of tongue as well as increase in the intercanine

width (Cetlin & Ten Hoeve, 1983).

II. Removable Functional Appliances: One of the effects of the functional

appliance is correction of molar relationship. This is mainly achieved by

skeletal changes (19% maxillary base and 22% mandibular base) as well as

dentoalveolar changes (26% maxillary dentition and 33% mandibular

dentition) (O’Brien, 2003).

III. Headgear (HG): It is attached directly to molar bands on the first molar

(mainly upper) in a high or low pull direction depending on the incisor

overbite. The force level is 250-300gm per side and the appliance used 14

hours/day. It could achieve 2-3mm of molar distalisation (Atherton et al.,

2002)


IV. Upper Removable Appliance (Nudger appliance): consists of 0.6mm

palatal finger springs or screw as an active component. Southend on the

incisors as well as Adam clasps on molars and premolars (except the tooth

to be moved) would aid in retention. Sometime, if there is extensive

space loss, an anterior biteplate may be needed to free up the occlusion

to permit uprighting of the tilted permanent molar. However the

anchorage loss manifests as an increase in the overjet (Lewis & Fox,1996)

V. Nudger appliance and HG combination: An upper removable appliance

(URA) with palatal finger springs (activation of 2-3mm) that acts to tip the

crown of the molar distally. High-pull headgear at night, directed above

the centre of rotation of the molar, acts to distalise the root and hold

the movement achieved during the day time by the URA, (Cetlin & Ten

Hoeve, 1983). In addition, the headgear provides a method of reinforcing

the anchorage during subsequent retraction of the anterior teeth. Ferro et al

(2000) showed an average of 20-25% anchorage loss with a Nudger

appliance used with cervical headgear.

VI. En mass removable appliance: It involves upper removable appliance to

which a headgear (200-300gm per side for 14 hours) is attached through a

facebow. Extraction of the upper second molars may be required and this

claimed to achieve 6mm molar distalisation (Orton, 1996).

VII. Molar Distalising Bow: It consists of two components. First, a 0.8–1.5 mm

thick thermoplastic splint covering all teeth except the teeth to be moved

and it extends into the buccal sulcus for better support and retention. A

distalising bow fits into the anterior slot that is embedded in the splint and

carries an open coil springs to apply a force to the molars. (Rakosi, 1991)


VIII. Class II Mechanics (CLII elastic with sliding jigs): This was a mainstay

of the original Tweed technique in which the force from Class II elastics

aid in pushing the upper molars distally via a sliding jig. The force level is

250 gm per side is needed. In addition the class II elastic help in correction

of class II malocclusion by clockwise rotation of the occlusal plane which

can be compensated in growing patient. This is why it should not be used

for more than 6 months in adult patient (Tweed, 1967)

2. Non-compliance CLII correctors

Classification of non-compliance CLII correctors (McSherry 2000)

Inter-maxillary

1. Herbst appliance

2. Jasper Jumper™

3. Adjustable bite corrector™

4. Saif Springs

5. Eureka Spring™

6. Mandibular anterior repositioning appliance (MARA)

7. Fixed twin-block

8. AdvanSync Molar-to-molar appliance developed by Terry Dischinger

Intra-maxillary

1. Pendulum/Pend-X appliance


2. Modified Nance arch with nickel-titanium coils or wire

3. Distal jet

4. Jones Jigs & Lokar distalizing appliance

5. Magnetic appliances

6. Absolute anchorage (Palatal implants, TADs, Onplants)

The Herbst appliance

A. History: It was first described by Dr Herbst and popularized by Pancherz

1979.

B. Design:

Fixed functional.

Bands on upper and lower 6’s and 4’s

Palatal bar and lingual bar

Telescopic arms form upper 6’s to lower 4’s

C. Advantages

According to O'Brien study 2009, Herbst was superior to Twin Block

when we measured:

Speech interference

Disturbance of sleep

Influencing school work

Feelings of embarrassment


Better success rate than Twin Block

It can be used with fixed appliance. Recently a Flip-Lock Herbst

assembly with the 'male' attachments welded to rectangular tubing, which

is slid over a rectangular archwire. This mechanism is very simple to

install and to date is encouragingly robust.

D. Disadvantages

1. Expensive

2. Breaks more significant and mechanical failure of piston assemblies.

3. Cement problem

4. Removal difficulty.

5. Enamel decalcification.

6. Recommended in the permanent dentition only

7. If joined with FA treatment, it should use when full arch SS in use.

8. Inability to incorporate arch expansion during the functional phase

9. Do not grow mandibles and in contrast to others, there is evidence of

sufficient satisfaction with other simpler functional - in particular the

twin-block.

10.More lower incisor proclination

E. Effects of the Herbst Appliance

1. Restraining effect on maxillary growth

2. A stimulating effect on mandibular growth.


3. Sagittal molar correction was 43 per cent due to skeletal changes and 57

per cent due to dentoalveolar changes.

4. The overjet correction was 56 per cent due to skeletal changes and 44 per

cent due to dento-alveolar changes. Pancherz (1979)

5. Dento-alveolar changes include lower incisor proclination and maxillary

molar distalization and intrustion. The changes are similar to those

produced by high pull headgear (Pancherz and Anehus-Pancherz, 1993).

6. Vertically, the overbite is reduced. This occurs by intrusion of lower

incisors and enhanced eruption of lower molars (Pancherz, 1995)

7. The long-term effect on mandibular growth is uncertain and may only have

a short-term effect on skeletal growth pattern (Pancherz and Fackel, 1990).

8. Hansen et al. (1990) found that the appliance did not have any adverse

effects on the temporomandibular joint (TMJ).

F. Indications

a. Dental Class II malocclusion.

b. Skeletal Class II mandibular deficiency.

c. Deep bite with retroclined mandibular incisors.

d. Pancherz (1995) also recommends its use in post-adolescent patients,

mouth-breathers, uncooperative patients, and those that do not respond to

removable functional appliances

G. Contra-indications


a. Cases predisposed to root resorption.

b. Dental and skeletal open bites.

c. Vertical growth with high maxillomandibular plane angle and excess lower

facial height.

Jasper Jumper

• The Jasper Jumper™ consists of two vinyl

coated auxiliary springs attached to the

maxillary first molars posteriorly and to the

mandibular archwire anteriorly with the springs

resting in the buccal sulcus.

• The springs hold the mandible in a protruded position.

• They are attached to the maxillary first molar headgear tube with a soft wire

with a ball on one end.

• The amount of mandibular advancement is adjusted by lengthening or

shortening the maxillary connection wire.

• The jumper mechanism fits over the lower archwire. (Blackwood, 1991).

• A heavy archwire with lingual root torque is used in the mandibular dental

arch in order to maintain lower anchorage.

• There also is a danger of lower incisor proclination if the archwire is not tied

back.

• Usually, 6–9 months of Jumper wear is necessary in order to correct a mild

Class II problem in patients who still have some growth remaining.


• Additional treatment time may be required in patients with more severe

problems.

Effects of the Jasper Jumper

Cope et al. (1994) quantified the action of the Jasper Jumper showing that

the majority of the action was due to dental, rather than skeletal change,

although the maxilla underwent significant posterior displacement and the

mandible clockwise rotation.

Indications

1. Dental Class II malocclusion.

2. Skeletal Class II with maxillary excess as opposed to mandibular

deficiency.

3. Deep bite with retroclined mandibular incisors.

Contra-indications

1. Cases predisposed to root resorption.

2. Dental and skeletal open bites.

3. Vertical growth with high mandibular plane angle and excess lower facial

height.

4. Minimum buccal vestibular space.

The Adjustable Bite Corrector™ (twin force )


The Adjustable Bite Corrector similar to

the Herbst appliance and the Jasper

Jumper.

The advantages include universal left

and right sides, adjustable length, stretchable springs, and easy adjustment

of the attachment parts. No long-term studies have been carried out on this

appliance in the present literature to date.

The Eureka Spring™

It is a fixed inter-maxillary force delivery system.

The main component of the spring is an open wound coil

spring encases in a telescoping plunger assembly.

The springs rest in the buccal sulcus and attach posteriorly

to headgear tubes on the upper first molars, and anteriorly

to the lower archwire distal to the cuspids

The appliance is designed to be used in conjunction with

heavy rectangular lower arch in place.

Labial root torque to the lower incisors

Buccal root torque should be applied to the upper first molars.

The appliance should only be used in conjunction with a transpalatal bar.

The effects of this appliance only dental


Saif Springs

These are long nickel-titanium closed coil springs that are used to

apply Class II inter-maxillary traction when fully banded

fixed appliances are in place .

The springs are available in two lengths 7 and 10 mm.

It can be used as CLIII elastic

Requirements

1. stabilization of each arch with a large rectangular archwire;

2. direction of force as horizontal as possible (from U7 not U6);

3. sufficient resistant torque (lower incisor lingual crown

torque);

4. perfect fit of bands;

5. proper placement of hooks for spring attachments

The Mandibular Anterior Repositioning Appliance (MARA)

It consists of Elbow shape wire attached to

tubes on upper first molar bands or stainless

steel crowns.

A lower first molar crown has arm projection

which engages the Elbow of the upper molar. The appliance is adjusted so

that when the patient closes, the Elbow wire guides the lower first molars

and repositions the mandible forwards into a Class I relationship.


It is recommended a 12-month treatment time to achieve a bite jumping or

orthopaedic effect.

Stabilization of the lower molars is assisted by the fitting of a lingual arch

and on the upper arch a transpalatal bar to stabilize the upper molars is

placed.

This appliance does not require the placement of attachments on teeth other

than the first molars.

The treatment results of the MARA were very similar to those produced by

the Herbst appliance but with less headgear effect on the maxilla and less

mandibular incisor proclination than observed in the Herbst treatment

group. Pangrazio-Kulbersh 2003

The AdvanSync appliance

A. History: Developed by Terry Dischinger in 2008

B. Design:

This molar-to-molar fixed functional assembly

The name of the appliance therefore reflects that the mandible can be

postured forward synchronously with the start of all the other fixed

appliance tooth movements.

The appliance requires no laboratory work

Molar band separation at one visit permits selection and cementation of the

molar attachments at the next visit.

These attachments are similar to a hybrid between a molar band and a

preformed crown.


The telescoping arms have a long range of action and permit good lateral

excursion and are very easily advanced either by means of the alternative

screw position on the lower molars or via C rings which are crimped over

the pistons.

Fixed twin block

A. History: Developed by Mike Read (2001).

B. Advantages

Robustness and possibly patient comfort

Because the two halves of the appliance are not permanently linked

together, the problems of leverage on the fixation points does not arise

during mandibular excursion in contrast to Herbest appliance.

Integration of FA is easy from the start

No lateral open bite.

C. Disadvantages

• OH problems and decalcification

• Need for lower premolar bands to remain securely cemented.

• Not quick and easy for all clinicians to make, fit and adjust as well as

robustness.

• Need technical development and extra experience are continually bringing

improvements.

Intra-maxillary

Pendulum Appliance

This appliance first described by Hilgers (1992)


It uses a large Nance button in the palate for anchorage and 0•032-inch

(0.8mm) TMA springs that deliver a distalizing force to the upper molars.

The springs insert into lingual sheaths on the palatal surface of the band.

The anterior portion of the appliance is retained with premolar bands, which

are joined to the appliance using a retaining wire (or can be bonded to the

tooth directly).

Occlusally-bonded rests on the primary molars or second premolars add to

the retention.

If expansion of the upper arch is indicated, then a midline screw can be

added to the appliance. This version of the appliance is known as the Pend-

X appliance.

Evidences

Byloff and Darendeliler (1997) showed that

The appliance moved molars distally without creating bite opening, but the

molars did tend to tip.

3mm of distalization associated with 1mm of anchorage loss.

If molar uprighting bends were incorporated into the appliance it reduced the

tipping, but increased the anchorage loss to 1.5mm for each 3mm of

distalization. (Byloff et al., 1997).

Ghosh and Nanda (1996) showed that

for every millimetre of distal molar movement, the premolar moved

mesially 0•75 mm.


Hilgers (1992) reports that when

The appliance is placed before the eruption of the second molars, two-thirds

of the tooth movement is molar distalization, one-third is experienced as

forward shift of the anchor bicuspids.

If placed after eruption of the second molars, the experience tends to be

reversed, one-third distal movement of the first molar, and two-thirds

anchorage slip.

Pendulum appliance provides a better patient perception and shorter duration

of treatment in comparison to HG in relation to (Ye et al 2005)

Jambi et al in their Cochrane review in 2013 suggested that intraoral

appliances are more effective than headgear in distalising upper first

molars. However, this effect is counteracted by loss of anterior anchorage,

which was not found to occur with headgear when compared with intraoral

distalising appliance in a small number of studies. The number of trials

assessing the effects of orthodontic treatment for distilisation is low, and

the current evidence is of low or very low quality

Retention after pendulum

However the molars were moved distally, they must be held there while the

other teeth are then retracted to correct the overjet.

Simply leaving the distalization appliance in place for 2 to 3 months leads to

distal movement of the premolars by stretched gingival fibers,


As soon as the original premolar-based lingual arch and palatal pad are

removed, a new lingual arch and pad from the distalized molars must be

placed.

Even so, especially if the molar tipped distally, it will tip mesially again as

the space closes.

Placing a tipback in the distalizing springs will keep the molar more upright

and minimize relapse, but this increases the extrusive tendency, so as with

headgear, the most successful molar distalization with the pendulum

appliance occurs in patients who have vertical growth during their

treatment.

Even so, data show that on the average, much of the original distalization is

lost during the second phase of treatment with a complete fixed appliance

Jones Jig™ and Lokar Distalizing Appliance

These appliances use open coil nickel-titanium

springs in to the upper first molars, and use a

Nance button attached to the upper first or

second bicuspids or the primary molars (Jones

and White, 1992).

A similar mechanism, called the Lokar distalizing appliance, has been

developed by Ormco Corporation. It has reported advantages of ease of

insertion and ligation.

Paul & O’Brien (2001) found no difference between Nudger URA+HG

and Jones jig for molar distalisation.


Distal Jet

Developed by Carano et al. (1996)

They claim that it overcomes the disadvantages of other appliances for

distalizing molars by reducing the tendency for the teeth to tip. The force

acts through the centre of resistance of the molar and

thus is said to translate the tooth

Bilateral tubes of 0•036-inch internal diameter are

attached to an acrylic Nance button. A coil and screw clamp are slid over

the tube.

The wire from the acrylic ends in a bayonet bend and inserts into a palatal

sheath on the molar band.

The Nance button is also attached to a premolar band via a connecting wire.

Bondemark (2004) in a randomised controlled trial compared HG and the

distal jet and found that the distal jet was more effective than the HG in

creating distal movement of maxillary first molars but anchorage loss was

greater with the distal jet.

Nance Arch and Coil Springs

Several authors have described the use of a modified Nance arch with coils

to distalize molars.

One of these studies compared the effect of modified Nance arch with coils

MNA and the repelling rear earth magnet RRRM in distalising the molars.

It showed that the amount of molar distalization was more in the MNA


group than RRRM group with a better patient perception with the former

group. (Bondemark et al, 1994)

Repelling Magnets

it had been showed that it is possible to achieve molar distalisation using

repelling magnets with a faster result when second molars are unerupted

(Bondmark, 1992).

However one of the difficulties of using the magnet is the force decay over

time with subsequent needs for frequent activation (weekly basis) in

addition to difficulty of using it with other metallic appliances like

headgear (Gianelly et al. 1989).

Anchorage loss in a form of increased OJ is a normal findings

Goshgarian appliance

Goshgarian appliance can be used in distalization the molars unilaterally or

bilaterally to correct mild class II by complicated ways of activating the V

shape bend of the TPA as described by Rebellto in 1995.

In unilateral case it is better to reinforce the stable side with headgear, place

torque in the archwire to take advantage of cortical anchorage or use

temporary anchorage devices (Haas, 2000, Burston 1980, Rebellto, 1995,

Cooke and Wreakes, 1978; Ten Hoeve, 1985; Dahlquist et al., 1996;

Ingervall et al., 1996, Rebellto 1995, Ten Hoeve, 1985; Man-durino and

Balducci, 2001)


Implant

Mini Implants: Ismail & Johal (2002) used mini implants for anchorage to

distalise molars.

They showed that suitable sites for the implant

are palatal vault and retromolar region.

If extractions of the second molars are carried

out then 4-5mm of distalisation is achievable.

Other uses of the miniscrew implant in the distalisation of the molars is by

supporting distal jet appliance (Karaman et al 2002) or bone anchored

pendulum anchorage (Kircelli et al, 2006)

Retention after molar distalization

Hilgers 1998

1. Overcorrection

2. Quick-Nance

3. Short term headgear

4. Stops on archwires

5. Upper utility arch

6. Class II elastics

7. Lip bumper

8. Hawley or clear-type retainers

9. Bionator

10. Herbst appliance


In details

Overcorrection

Simply put, just moving the upper molar back into a Class I occlusion is

most often not enough. Moving it back into a Class III relationship is more

desirable.

Quick-Nance

It preformed Nance cribs fabricated from .032 stainless steel, The .032

wire size is utilized because it is easily placed recurved to fit into the .036

lin-gual sheath.

The Nance button cannot be placed over already inflamed or compressed

tissue. When the palatal tissue is inflamed, the use of a clear immediate

(Tru-Tain type) retainer for approximately one week will allow for

adequate recovery of the tissue.

Short-term Headgear

It also helps distally upright molar roots.

The outer bow is kept high, above the center of resistance of the tooth, and

moderate-force loads applied (250-350 grams/side).

Stops on Archwires

This will prevent the upper molars from sliding forward

By placing a stop at the molar, any rebound will be expressed as flaring or

forward movement of the upper arch. Therefore, other anchorage

techniques must always be used in conjunction with stops on the archwire.


Upper Utility Arch

Indications

1. Can be used without full eruption of the buccal segment teeth,

2. There is no loss of anchorage caused by archwire friction when retracting

the buccal segments.

3. In class II D2 with sever deep bit because any rebound would be beneficial

to proclined the severely retroclined upper incisor and thus reducing the

overbite.

4. If Cl II elastics are going to be one of the anchorage sources , the utility

arch acts as the forward purchase point for the elastics.

Class II Elastics

Early use of Class II elastics means early bonding of the lower arch, which

can be difficult with the locked-in overbite. A utility arch or reverse curve

Ni-Ti is often used at the very outset of Pendulum therapy to clear the

lower arch for bonding.

Upper Lip Bumper

An .040 lip bumper with a soft covering in the labial vestibule is adapted

above the upper incisor brackets.

Clear (slipcover) or Hawley-type retainers

Utilized when tissues are too inflamed for immediate transition to fixed

appliance.


Bionator

The Bionator or removable functional appliance is used for Pendulum

anchorage in those brachyfacial types with short mandibular corpus length.

It serves to maintain the distalized molar position while developing the

lower arch forward.

Herbst appliance

This version of the classical Herbst appliance is easy to use, allows for

adjunctive bonding and space closure of the upper arch .

Summary of the evidences

1. Indications for Molar Distalization as Interceptive applications

(Leonardi, 2004) To provide space for spontaneous eruption of

ectopic canines. This has been shown to have a success rate of 80%

compared to 50% in control group

Kennedy, 1987).To regain a lost space due to mesial migration of

molars in premolar crowding cases

Kurol & Bjerklin, 1984)Uprighting of upper first molars when they

are impacted against upper deciduous second molars

2. Limitations & Contraindications of distalization,

Atherton et al, 2002) Significant crowding more than 6 mm) since

the maximum amount of space regaining by molar distalization is 2 -

2.5mm

Atherton et al 2002) Amount of Distalization, in their systematic

review came to the conclusion that the most distal movement of the

molars that could be achieved was in the range of 2 - 2.5mm.


Melsen and Dalstra 2003) in their retrospective study found that the

total distal movement of the molars in patients who wore cervical

head-gear for an 8-month period did not differ from that of an

untreated group when re-evaluated 7 years later.

3. Karlsson 2008, Timing of Distalization, concluded that the best time

to move maxillary first molars distally is before eruption of the second

molars

4. Cetlin & Ten Hoeve, 1983).lip bumper

5. O’Brien, 2003) Removable Functional Appliances: One of the effects

of the functional appliance is correction of molar relationship. This is

mainly achieved by skeletal changes 19% maxillary base and 22%

mandibular base) as well as dentoalveolar changes 26% maxillary

dentition and 33% mandibular dentition

6. Cetlin & Ten Hoeve, 1983).Nudger appliance and HG combination

7. Orton, 1996).En mass removable appliance Extraction of the upper

second molars may be required and this claimed to achieve 6mm

molar distalisation

8. Rakosi, 1991) Molar Distalising Bow

9. Tweed, 1967) Class II Mechanics CLII elastic with sliding jigs):

10.O'Brien study 2009, Pancherz, 1995) The Herbst appliance

11.Cope et al. 1994), Effects of the Jasper Jumper

12.Mike Read 2001). Fixed twin block

13.Hilgers 1992): The appliance is placed before the eruption of the

second molars, two-thirds of the tooth movement is molar

distalization, one-third is experienced as forward shift of the anchor

bicuspids. If placed after eruption of the second molars, the


experience tends to be reversed, one-third distal movement of the first

molar, and two-thirds anchorage slip.

14. Ye et al 2005) Pendulum appliance provides a better patient

perception and shorter duration of treatment in comparison to HG

15.Paul & O’Brien 2001) found no difference between Nudger URA and

Jones jig for molar distalisation.

16.Bondemark 2004) found that the distal jet was more effective than the

HG in creating distal movement of maxillary first molars but

anchorage loss was greater with the distal jet.

17. Bondemark et al, 1994) showed that the amount of molar distalization

was more in the MNA group than RRRM group with a better patient

perception with the former group.

18.Mini Implants: Ismail & Johal 2002) used mini implants for

anchorage to distalise molar

19.One of the important systematic review worth mentioned is that done

by Karlsson 2008. He did a systematic review of two RCT studies and

found that the intraoral appliances for molar distalization are more

effective than the extraoral one. However, he recorded a moderate and

acceptable anchorage loss was produced with the former implying

increased overjet whereas the latter created decreased overjet. Bother

appliance did not have any considerable corrective skeletal effect.

Finally he concluded that the best time to move maxillary first molars

distally is before eruption of the second molars.


molar distalization by almuzian

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