extra oral appliances by almuzian

Extraoral Orthodontic Appliances

Mohammed Almuzian

JANUARY 1, 2013university of glasgow

Scotland, UK

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Contents• Definition

• Types of extra-oral appliances

• History

• Uses (indications of HG)

• Anchorage reinforcement

• Interceptive uses

• Dental movement

• Growth modification or orthopedic appliances

• Studies about the effects of HG

• Types of Headgear

• Headgear with facebow

• J hook facebow

• Asymmetric Headgear

• Headgear to URA/Functional appliance combination

• Nudger appliance HG

• B. En mass removable appliance

• C. HG and Dynamax

• D. Headgear to upper part of the Twin block

• E. The Intrusive Myofunctional Appliances

• Controversies of the use of TPA with HG

• Complications of Headgear appliances

• Four Types of Headgear Injuries in Europe

• Safety Advises and mechanism in the use of Headgear and Facebow

• Safety release headgears

• Safety facebows

• Miscellaneous safety products

• In case of HG/URA combination

,Extraoral Orthodontic Appliances Mohammed Al-Muzian, University of Glasgow, 2013

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• Written and verbal instruction & advice

• Force affecting factors

• Direction

• Position of the force in relation to center of resistance

• Magnitude

• Duration

• Decline in our personal use of headgear

• Protraction Headgear

• Definition

• History

• Indications

• Timing

• Effects

• Evidence based short term effectiveness of PH

• Evidence based long term effectiveness of PH

• Protraction face mask system

• Chin Cups

• Types

• Best patient for Chin cup therapy

• The effects of chincup therapy

• Reverse chin cup therapy

• Summary of the evidence

• References


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Extraoral orthodontic appliances

Definition

It provides a means of applying anterior, posterior or vertical directed forces to

the dentition and skeletal complex from an extra-oral source (Turner 1991)

Types of extra-oral appliances

1. Headgear with facebow or J hook.

2. Reverse facial mask

3. Chin cap or reverse chin cap

History

HG introduced in the late 1890's by Kingsley then by Angle in

1910.

By 1920, it was disused as it was believed that intra-oral

elastics would suffice (Angle).

Re-used again in the 1940's after lateral cephalometric

radiographs showed the adverse effects of intra-oral elastic

traction.

Uses (indications of HG)

1. Anchorage reinforcement

Reinforcement of anchorage to prevent forward movement or to counteract

extrusion of anchor molars.


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Feldmann, 2009, RCT to measure the anchorage loss with Onplant (1), TAD (2),

EOT (3) & TPA (4). They found that after levelling/aligning phase: the

anchorage was stable in the group 1,2 & 3 while group 4 showed 1.0 mm.

while after space closure phase, the anchorage was stable in the group 1 & 2 but

group 3 & 4 showed 1.6 and 1.0 mm of mesial drift of molars respectively.

Feldmann, 2012, measured the patients’ perceptions in term of pain, discomfort,

and jaw dysfunction with Onplant (1), TAD (2), EOT (3) & TPA (4). The results

confirm that there were very few significant differences between patients’

perceptions of skeletal and conventional anchorage systems during orthodontic

treatment

TADs or HG? Junqing in 2008 showed again a better result by TADs in

comparison with HG.

2. Interceptive uses

A. To provide space for spontaneous eruption of ectopic canine as interceptive

treatment with a success rate of 80% compared to 50% in control group.

(Leonardi, 2004).

B. Uprighting impacted U6s against UEs.

C. To maintain the space after premature loss of primaries.

D. To regain a lost space due to mesial migration of molars (premolar crowding

cases).

3. Dental movement

I. Distalization movement

To correct less than 1/2 unit Class II molar relationship aiming to correct mild

increased in the OJ in non-extraction cases or to provide space to relief mild

crowding


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To provide extra space in sever space deficiency in which extraction fail to

provide sufficient space.

HG with J hook to individually retract U3 or rarely, retract L3 (problem with

patient toleration)

Differential (asymmetric) movement for treatment of ML problems

II. Transverse teeth movement (minor maxillary dental expansion)

III. Vertical teeth movement (intrusion or extrusion of UBS or ULS) or anterior

teeth when it is combined with auxillary wires like tandem (Hans)

IV. Teeth de-rotation.

4. Growth modification or orthopedic appliances

Appliances that restrains anterior and/or vertical growth of the maxilla

The best age is 12-13 years since early treatment offer no advantages over

late single phase treatment (Tulloch, 2004, Dolce 2007). Ghafari 1998 suggest

the use of HG before loss of Es in order to use the Leeway space.

It acts by influencing the pterygopalatine, fronto-maxillary, zygomatic

maxillary sutures.

Studies about the effects of HG

1. Dental effect 1. Enmass retraction with HG plus extraction of the

upper second molars claimed to achieve 6mm molar

distalisation (Orton, 1996).

2. Atherton et al. (2002) came to the conclusion that the

most distal movement of the molars that could be

achieved was in the range of 2 - 2.5mm.

3. Firouz 1992 showed that the amount of intrusion

achievable by HG is 0.5mm


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4. Melsen and Dalstra (2003) in their retrospective

study found that the total displacement of the molars

in patients wearing cervical headgear for an 8-month

period did not differ from that of an untreated group

when re-evaluated 7 years later

5. Bondemark (2009) 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.

2. Skeletal changes 1. Mills 1978 in a review, stated a maxillary growth

suppression effect of 1-2 mms is possible in humans

with Kloehn bows

2. Wieslander, 1993,1mm of maxillary growth restraint

achieved over a 10 year period that persists post-

treatment

3. Tulloch et al 1997 (class II D1 OJ 7mm, HG, Bionato

or CG for 15 months) concluded that the bionator

produced some mandibular change, whereas, with the

headgear, there was some maxillary restraint. In the

TG (HG or Bionator) the improvement in the ANB in

70-80% while no improvement in 20%. In the CG no

improvement 50%, improvement 30% and worsening

20%.

4. Then Tulloch 1998 followed the patient and found

that skeletal improvement are lost after 1 year.

5. Keeling et al 1998 (HG/Biteplane, Bionator, CG, OJ


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7mm for 2 years or until class I achieved) suggested

that a headgear biteplane combination resulted in no

restraint of the maxilla but forward positioning of the

mandible.

6. Ghafari et al 1998 suggested that headgear produces

some maxillary restraint and the Fränkel, mandibular

growth increase.

3. compliance HG failure rate 5% for female and 25% for male

(Ghafari 1998)

Types of Headgear

A. Headgear with facebow

Original Kloehn bow

Kloehn loop style facebow.

Asher Facebow

Bite Plate Facebow

B. J hook facebow (not used anymore in UK for safely reasons)

C. Asymmetric Headgear

Power-arm face-bow

Soldered-offset face-bow

Swivel-offset face-bow

Spring-attachment face-bow

D. Headgear to URA/Functional appliance combinations

Nudger appliance HG

En mass removable appliance

HG and Dynamax

Headgear to upper part of the Twin block


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The Intrusive Myofunctional Appliances

1. The Van Beek appliance

2. Tauscher appliance

3. The Buccal Intrusion Splint (BIS)

4. The Maxillary Intrusion Splint (MIS)

5. The Maxillary Intrusion Splint and Lower Traction Plate (CONCORDE)

In details

1. Headgear with facebow

A. Original Kloehn bow

It invented by Kloehn 1947 after World War II.

Inner bow diameter 1.13mm

Outer bow diameter 1.45mm

B. Kloehn loop style facebow.

The loop aids in providing an attachment to

elastics.

C. Asher Facebow

Used by Dr. Ron Roth

Intrudes anterior teeth

Pushes on Archwire

D. Bite Plate Facebow

Intrudes anterior teeth, Pushes on anterior teeth,

two main styles: loop style or regular style


http://www.orthokineticscorp.com/wordpress/wp-content/uploads/2011/06/Asher-facebow-Basics-of-Orthodontic-Headgear.jpg

http://www.orthokineticscorp.com/wordpress/wp-content/uploads/2011/06/Bite-Plate-facebows-Basics-of-Orthodontic-Headgear.jpg

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2. J hook facebow (not used anymore in UK for safety reasons)

Uses

Distalize the canine . If force heavy enough - then it can

move 5/5 and 6/6 distally also.

Intrusion of anterior teeth but less efficient than TADs

(Degushi, 2008)

It also restrains maxillary development.

"J" hook headgear can also be used asymmetrically to

resolve a centre line problem by judicious use of the

hooks to contralateral upper and lower canines e.g. UL3 &

LR3.

Mechanics

I. J hook traction engaged in stops soldered or crimped onto the archwire between

the lateral incisor and the canine or attached to an attachment on the tooth

directly.

II. Hickman (1974) - devised a headgear which will accept 2 or even 3 "J" hooks

each side.

Problems

I. Accidental injuries

II. Root resorption. Linge and Linge 1983

III. The headgear's expansion effect on the arch wire. For this reason, it is important

to contract the arch wire from the canines distally in order to resist this effect

(Berman, 1976).

IV. "J" Hook straight pull headgear to the lower arch in Class III cases cause the

mandible to rotate in clockwise direction.

V. There is significant binding and friction, not only where teeth slide along the

archwire but also within the headgear mechanism itself because the headgear


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wires that attach to the teeth tend to bind against their protective sleeves.This

makes it difficult to control the amount of force, and more net force on one side

than the other may lead to an asymmetric response. In fact, it is usual if space

does not close faster on one side than the other.

VI. Degushi 2008 compared TAD with J hook for intrusion and found the

result is 3.1 and 1.3mm respectively.

3. Asymmetric Headgear

Results in more movement on the side with the longer outer bow according to

Castagliano's Theorum

Problem: it lead to that same tooth becoming susceptible to lingual crossbite


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Types of asymmetrical HG

1. POWER-ARM FACE-BOW

2. SOLDERED-OFFSET FACE-BOW

3. SWIVEL-OFFSET FACE-BOW

4. SPRING-ATTACHMENT FACE-

BOW

4. Headgear to URA/Functional appliance combinations

A. Nudger appliance HG

Uses:

1. Used for true unilateral space loss with

subsequent loss of space.


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2. Class II subdivision

3. Correction of ML deviation

4. It can be used bilaterally to gain space to correct OJ or relief crwoding

Design:

1. Band molar teeth

2. Fit URA with palatal cantilever spring 0.7mm SS on the molar requiring distal

movement.

3. Retention from Adam clasp on premolars, Southern end clasp on incisors but on

molars try to use Plint clasp because of the presence of the molar bands.

4. Alternative ways of differential movement of 6/6: asymmetrical extraction of the

7s with normal Kloehn Bow and/or URA screw appliance

Mechanism of action:

1. An upper removable appliance (URA) with palatal finger springs acts to tip the

crown of the molar distally.

2. High-pull headgear at night, directed above the center 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).

B. En mass removable appliance

1. It involves upper removable appliance to which a headgear (200-300gm per side

for 14 hours) is attached through a Facebow or it the HG can be attached to

molar tubes and over it there is a URA.

2. Extraction of the upper second molars may be required and this claimed to

achieve 6mm molar distalisation (Orton, 1996).


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C. HG and Dynamax

D. Headgear to upper part of the Twin block

1. Park 2001used TB with HG and torqueing spring and

compared it to conventional TB and found that better

control of ULS inclination.

2. It is also indicated in high angle class II malocclusion

E. The Intrusive Myofunctional Appliances

1. The Van Beek appliance

Described by Pfeiffer (1972) to reduce the duration of

treatment significantly.

This prompted Van Beek to design a simplified short

outer arm facebow embedded in the acrylic part of the

Harvold activator (Myotonic functional appliance) or HG

tubes within the acrylic to accept the facebow for the high-pull headgear.

There is full palatal coverage and fully extended lingual flanges

300 gms of force/12 hours a day

2. Tauscher appliance

It is similar to Van Beek but with HG attached to

posterior segment of activator and with torqueing

spring

3. The Buccal Intrusion Splint (BIS)

This appliance consists of an acrylic palatal baseplate which is clear of the upper

anterior teeth and with occlusal capping on the teeth in occlusion.

There are double Adams cribs present on the upper first permanent molars and

first premolars and molar tubes embedded in the occlusal capping acrylic to

accept a Kloehn facebow near the area of maxillary rotation (premolar area).


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There is a midline screw present in the palatal acrylic.

This appliance is used to treat skeletal anterior open bites by intrusion of the

upper buccal segment teeth.

4. The Maxillary Intrusion Splint (MIS)

• This appliance consists of an acrylic baseplate which extends over the occlusal

surfaces of all teeth and onto the labial surfaces of the upper anterior teeth.

• There are Adams cribs present on the upper first permanent molars and first

premolars, along with a Southern clasp on the upper central incisors.

• There are headgear tubes present within the molar capping

• This appliance is designed to be used for patients with a Class II division 1

malocclusion and a "gummy smile" with an overjet of 6 to 8mm. .

5. The Maxillary Intrusion Splint and Lower Traction Plate (CONCORDE)

• This is a two part appliance which consists of a maxillary intrusion splint as

described above along with a lower appliance.

• The lower appliance consists of an acrylic baseplate with no occlusal or incisor

capping. There are double Adams cribs present on the lower first permanent

molars and second premolars, and a semi-fitted labial bow on the lower incisors.

• There is a lingual hook on the lingual aspect of the acrylic baseplate to enable

elastics to be attached to the midpoint of the facebow.

• The selection criteria are the same as for the maxillary intrusion splint but these

combined appliances work more effectively at reducing overjet between 9 to

18mm than the maxillary intrusion splint alone.

• This appliance combination can also be used for the treatment of a severe Class

II division 1 malocclusion with a "gummy smile" and an average face height.


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Controversies of the use of TPA with HG

For minimal overbites and small anterior open bites, successful results can be

achieved by careful control of the buccal segments in the vertical dimension.

The point of application of the force however tends to result in more intrusion of

the buccal cusps than the palatal cusps.

The use of a transpalatal bar on the first molars can prevent dropping of the

palatal cusps of the first molars.

The transpalatal bar design used was fitted 1-2 mm off the palate.

In a study by Wise et al (1994) which compared 20 non-extraction patients in

which a transpalatal bar was used for at least 5 months with similar patients in

whom it was not used, no significant differences were found between the two

groups.

Complications of Headgear appliancesTeeth related

AP Distal tipping of the molars& Distal tipping of the canine in

case of J hook

Transversely Increased buccal crown torque (reduced by rigid TPA, Scissor

bite effect of J hook, Crossbite effect of Kloehn bow and

asymmetrical HG(this can be counteracted with either a

removable upper appliance with screw expander or by

widening (expanding) the inner bow).

Vertically Increase anterior facial height and gingival show due to

mandibular clockwise rotation as a result of molar extrusion

and the patient will show CL2 profile (O'Reilly et al.1993).

Rotation of the molars and canines

Patient related

Patient Cooperation Not all patients are honest in actual compliance. Using time

charts can increase co-operation (Cureton et al. 1992, 1993).

Biological variability Growth may be unfavorable

Pain Heavy force and necrosis


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Root resorption a possibly with J hook headgear and this should be monitored

radiographically, e.g. long cone Periapical

Nickel allergy Contact dermatitis-type IV delayed hypersensitivity immune

response (Rahilly and Price, 2003).

Intra-oral injuries Oral soft tissue injuries

Extra-oral injuries Facial and skin trauma

Rarely eye injuries (0.12% chance as per the AAO survey in

1982) can occur whilst wearing headgear with a serious

consequences involving the entrance of the oral bacteria in

the eye with subsequent impaired vision, loss of eye (Holland

1985), sympathetic opthalmitis, (Samuels and Jones, 1994;

Booth-Mason and Birnie, 1988), cavernous sinus thrombosis,

Chaushu, 1997.

Four Types of Headgear Injuries in Europe

Samuels 1993 (23 countries studied)

1. Incorrect handling during fitting or removal (8%)

2. Unintentional nighttime disengagement (71%)

3. Accidental disengagement while playing (17%)

4. Bully pulls headgear (4%)

Safety Advises and mechanism in the use of Headgear and Facebow

From Postlethwaite (1989) and Samuels 1993

1. Safety release headgears

Snap away mechanics: (easy release mechanics) Means that they are design to

break-away when excessive force applied to HG. This was developed by

Postlethwaite in 1989. It aims to prevent the catapult injuries.

NOLA system: same as anti-coil device but the device attached to the face bow

not the HG.


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Ideal physical properties for the HG safety mechanism according to the study of

Stafford on 1998:

1. Minimal extension: it means the amount of extension of the facebow from its

attachment with the molar bands before it break-away (stop releasing force). So

if accidental force applied in a direction to dislodge the facebow, this system

(anti-recoil device) will start working. It should be from 10mm-25mm

2. Low force: it means the amount of force applied to the facebow before it stops

release the force or break-away (Anti-recoil device)

3. High Consistency: which means the release point should be constant in all types

of HG after prolonged repeated use.

2. Safety facebows

a. Locking mechanism (NiTom): helps to avoid accidental remove of the facebow

which act by special locking device behind the distal end of the inner bow thus

preventing accidental dislodgment of the facebow. This is developed by Samuel

in 2000.

b. Re-curved reverse entry inner bow: it designed by Lancer Pacific but it is

difficult to use by the patient.

c. Locating elastic: Like class I elastic attach the inner bow to the teeth to stabilize

the facebow.

3. Miscellaneous safety products

A. Safe end (blunt end)

B. MASEL safety strap (rigid neck strap)

It is easy and cheap.

Works by adding an additional rigid safety strap to the HG to minimize facebow

movement and dislodgment.


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4. In case of HG/URA combination

a. Clip-over appliance. It means that the facebow should attached securely to

molar band while the URA clip over the bands

b. Integral face bow (soldering the inner bow to the URA)

c. Locking mechanism (same as point B)

5. Written and verbal instruction & advice

1. The way of inserting and removing the HG which include:

Place the facebow first

Ensure that the safety mechanisms are active during use.

Then place the headgear

Remove external headgear attachment before the inner bow. Never remove or fit

the headgear in one piece

2. Do not wear headgear while playing sports.

3. If the headgear comes detached during sleep, stop wearing the headgear

immediately and contact your orthodontist the next day.

4. If any eye injury associated with the headgear occurs; it must be treated as a

Medical emergency.

5. Bring your headgear to each appointment and report any problems to your

orthodontist.

Force affecting factors

Bowden 1978

1. Direction

Theory of Directional Forces (DF) - Merrifield and Cross (1970), DF angle =

"directional force angle" = angle made by the headgear line of force and the

functional occlusal plane.


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If DF > 60º. (vertical pull) - a force is produced which is 0 distal movement and

3/3rds intrusion upon 6/6.

If DF 20-50º. (high pull) - a force is produced which is 1/3rd distal movement

and 2/3rds intrusion upon 6/6.

If DF = 0-10º. (straight pull) - a force is produced which is 3/3rd distal

movement and 0 intrusion upon 6/6.

If DF = -10 to -20º (low pull) - this gives the force which is 1/3rd extrusive and

2/3rds distal upon 6/6.

2. Position of the force in relation to center of resistance

Two variables could determine the position of force in relation to center of

resistance includes:

A. Length of outer bow

B. The direction of pull

C. Clinical situation of thU7s (Unerupted 7's move distally in response to the

moving first molar. Fully erupted second molar causes more distal crown

tipping)

See these different scenarios:

a. Outer Arm short

If above center of resistance i.e. high pull - causes intrusion and distal tipping of

the root.

If below centre of resistance i.e. low pull - causes

extrusion and distal tipping of the crown.

Outer bow at the trifurcation point of 6/6 (center of

resistance. The result is pure translation. (this was

supported by paper from Bowden (1978) and Yoshida et al (1995).,Extraoral Orthodontic Appliances Mohammed Al-Muzian, University of Glasgow, 2013

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b. Outer arm long

If above centre of resistance i.e. high pull - causes intrusion and distal tipping of

the crown.

If below centre of resistance i.e. low pull - causes extrusion and distal tipping of

the root.

Outer bow at the trifurcation point of 6/6 (center of resistance. The result is pure

translation. (this was supported by paper from Bowden (1978) and Yoshida et al

(1995).

3. Magnitude

A. Different level of force for different requirements (and different clinicians!)

Weislander (1972) achieved 2mm of distillation of A point over 3 years with

only 300g of force

Armstrong (1971), Graber (1977) all used forces in excess of 400g, and

sometimes 2 or 3 times that amount to achieve rapid orthopaedic translations

Firouz (1992) showed that the rate of anterior displacement of A point was

significantly decreased by applying 500g of counter force.

Watson (1978) demonstrated that the ANS could move distally by as much as

4mm in 1 year by applying 1000g bilaterally.

A. Conclusion:

Force levels of 250-300g per side is adequate for anchorage

Force levels of 400-500g per side is adequate for teeth movement.

Force levels of 800-1000g per side is adequate for skeletal effects

4. Duration

Anchorage: 10 hours per day.

Distal movement:12-14 hours per day

Orthopaedic: 12-14 hours per day.


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Cureton et al. (1993) recommend the use of headgear charts routinely. Recently

the monitoring device like the Affirm headgear traction module has been used

(electronic timer) (Clark et al 2003)

Decline in our personal use of headgear

1. More class 2 elastics being employed

2. More lower incisor proclination accepted

3. Functional appliances which have better compliance

4. Fixed functional

5. Self-ligating brackets seem to reduce anchorage demands (not proven) and favor

earlier use of lighter class 2 traction

6. TADs have revolutionized intra-oral anchorage possibilities

Protraction Headgear

Definition

Means of applying anterior directed forces to teeth and/or skeletal structures

from an extra-oral source

History

The technique of maxillary protraction is based on work by Nanda (1978), with

rhesus monkeys in which he showed that a force of approximately 500g could

produce anterior displacement of the maxilla

It is appropriate to refer to this type of treatment as facemask therapy.

Indications

A. Treatment of maxillary retrusion. An ideal case would be;


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1. Patient’s factors

Good co-operation

No familial prognathism

2. Growth

Young growing patient

3. Soft tissue

Acceptable facial aesthetics

4. Skeletal

Mild skeletal discrepancy (ANB < -20 )

Normal MMPA

No asymmetries (Symmetrical condylar growth)

5. Dental

-2mm reverse OJ or edge to edge relationship

Retroclined ULS

Proclined LLS

6. Displacement

Functional shift

B. Reinforcement of anterior anchorage and dental protraction allowing closure of

space from behind in patients suffering from hypodontia

C. Stabilization following maxillary osteotomy/distraction osteogenisis

D. Rotate arch segments in cleft palate patients

E. Remove hyper-anterior contact in TMJ internal derangement cases,,Extraoral Orthodontic Appliances Mohammed Al-Muzian, University of Glasgow, 2013

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Timing

1. Dental age: McNamara (1987) suggested that the optimal time for treatment is

in the early mixed dentition, coincident with the eruption of the upper permanent

incisors.

2. Skeletal age: Baccetti et al (1998) showed that the early treatment group CVM2

showed effective forward displacement of the maxillary structures whereas the

late treatment group CVM3 showed no change compared with controls

3. Chronological age: Other investigators have suggested that for optimal

orthopaedic effects, treatment should be initiated before the patient is 9 years old

(Proffit, 2000).

4. Kim et al., 1999, meta-analysis of effectiveness of protraction HG concluded it

was less effective on patients >10yrs

Effects

1. Correction of a centric occlusion-centric relation discrepancy. This correction

happens relatively rapidly in patients with an edge to edge relationship and

associated displacement

2. Maxillary skeletal protraction

3. Proclination and forward movement of the maxillary dentition

4. Lingual tipping of the lower incisors

5. Redirection of mandibular growth in a downward and backward direction,

resulting in an increase in lower anterior facial height

Evidence based short term effectiveness of PH

Mandall, 2010 (similar to study of Ngan 1998)

Early Class III orthopaedic treatment with protraction face mask in

patients less than 10 years of age is skeletally and dentally effective in the short

term 15 months. (After 15 months of treatment, children undergoing early


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facemask therapy had 1.3 degrees more forward movement of SNA, almost

2degrees less forward movement of SNB and an overall ANB improvement of

around 2.6 degrees when compared to the control group. In addition, the overjet

improved by more than 4 mm and the relative PAR score by more than 40% in

the facemask compared to the control group. Thus, early class III protraction

facemask treatment in patients under 10 years of age would seem to be

skeletally and dentally effective in the short-term)

70% of patients had successful treatment, defined as achieving a positive

overjet.

Early treatment does not seem to confer a clinically significant

psychosocial benefit.

No negative effect on the TMJ

Evidence based long term effectiveness of PH

Mandal 2012: Early Class III orthopaedic treatment with protraction face

mask in patients less than 10 years of age is skeletally and dentally effective

after 3 years of treatment.

Masucci 2011: RME/FM therapy led to successful outcomes in about

73% of the patients. Significantly improved sagittal dentoskeletal relationships.

These favorable changes were mainly due to significant improvements in the

sagittal position of the mandible, but the maxillary changes reverted completely

in the long term. This treatment not induces a tendency of bite opening or

increased vertical relationship.

A Cochrane review by Watkinson in 2013. This review looked at the use

of four different types of orthodontic treatment for correcting prominent lower

front teeth in children.-Facemask-Chin cup-Mandibular -Tandem traction bow

appliance. This review found some evidence that the use of a facemask


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appliance can help to correct prominent lower front teeth on a short-term basis.

There was no evidence available to show whether or not these short-term

changes will still be maintained until the child is fully grown. There was not

enough evidence to support any other types of treatment for prominent lower

front teeth.

Protraction face mask system

A. Types Extraoral part

1. Protraction Headgear (Hickham)

2. Facial Mask (Delaire)

3. Suborbital Protraction Appliance (Grummons)

Advantages: frame more rigid, no force on TMJ, no LLS

retroclination, easy to adjust and wear during sleep

Disadvantages: not esthetic due to midfacial support

4. 4. Nola protraction appliance

5. Petit style face mask

The Petit style with a single central vertical bar is also well

tolerated and recent price changes have made it economically

much more attractive.


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B. Intraoral part:

1. In order to maximize the amount of skeletal change in young children, a

removable full coverage acrylic splint is used with a protraction headgear

(Proffit 1986).

2. McNamara (1987) has described the use of a Biocryl and wire splint that is

bonded in the mouth. The splint material should be at least 3 mm thick with a

0.045" stainless steel wire framework. The two halves of the splint are joined by

an expansion screw. Traction hooks to receive the elastics from the headgear are

placed in the first premolar region.

3. Some recommend using an intraoral bone plate to support the PHG force.

Systematic review to compare the dentally anchored face mask with skeletally

anchored one by Major (2012) in Canada, he found Approximately 3 mm of

horizontal A-point movement is predictably attainable with the skeletal one in

comparison to dental one..

C. Rapid maxillary expansion

Advantages (Haas 1973).

1. Sutural loosening

2. Correct transverse discrepancy that commonly associated with class III

malocclusion

3. Displace the maxillary complex anteriorly. This is due to butterfly effect of

expansion at the Midpalatal suture and because of the anterior sloping of the

facial sutures

Evidences


27

1. Many clinicians use protraction with a facemask following or simultaneously

with palatal expansion, because some evidence suggests that the expansion

makes antero-posterior skeletal change more likely. Kim et al (1999)

2. There is other evidence that the expansion is optional and should be dictated by

the maxillary arch width related to the lower arch width, Vaughan 2005.

D. Techniques

1. First step is to fabricate and bond/cement the rapid maxillary expansion

appliance

2. Appliance is activated once per day until the desired increase in maxillary width

has been obtained.

3. If patients do not need an increase in maxillary width, the appliance is still

activated for 7-10 days to disrupt the maxillary sutural system and promote

maxillary protraction (Haas, 1965)

4. After the patient activated the maxillary appliance for 7-10 days protraction

headgear is fitted.

E. Force level:

1. Moving maxillary anterior teeth forward: 400g per side, 12-14h/day

2. Maxillary protraction : 800g per side, 14h/day

3. Overcorrect to compensate for mandibular growth

4. Active treatment should be limited to 9-12 months because of the risk of

decalcification of the dentition

F. Force direction:

1. To avoid bite opening, place protraction elastics near maxillary bicuspids,

2. Force vector should be 15-30 degree below the horizontal

3. To avoid irritation to the lip, use crossed elastic,

4. Pay special attention to airway and tongue posture


28

5. Ishii et al (1987) describe the effects of providing the protraction force from the

first molars or the premolar region. Protraction from the first molars results in

more anterior movement and a forward and upward rotation of the maxilla;

protraction from the premolars results in less forward movement but less

tendency to upward and forward rotation.

G. Transitional period

After treatment objectives have been achieved, the patient can be retained with a

number of appliances:

The facemask,

Acrylic maxillary retainer,

FR-3 appliance

Chin cup (seldom used).

H. Post protraction treatment consideration

1. As mandibular growth exceeds maxillary growth during adolescence, early

Class III correction may be lost during the teenage period. The patients and

parents should again be warned of the possibility of orthognathic treatment if

growth is unfavorable

2. Upper labial root torque during fixed appliance stage: Most class 3 patients

demonstrate considerable proclination of the upper labial segment at the end of

treatment. Catania et al (1990) recommend in his case report to use inverted U

incisor bracket to counteract the effect of proclination.

Chin Cups

The idea of this appliance is that because the condyle is a growth site, the

growth impeded by extra-oral force (Graber, 1977).


29

Despite success in animal experiments, most human studies have found

little difference in mandibular dimensions between treated and untreated

subjects (Sugawara et al, 1990).

Chincup appliances greatly improve the skeletal profile in the short term

such changes are however rarely maintained during the pubertal growth spurt

Force 500g per side 12-14 h/day for 4-5 years.!!!! Once the anterior

crossbite was corrected, the patient was instructed to wear the chin cup at least

10 hours per day until slight Class II canine and molar relationships were

established.

The best age is before canine and premolar erupt (CS2-CS3 maturity) this

is the first growth spurt of mandible, the second one when 7 and 8 erupt CS4-

CS6 (Bacceti, 2005).

Types: occipital pull, used for patients with mandibular prognathism or

vertical pull, used for patients with increased anterior face height

Best patient for Chin cup therapy

Ko et al (2004)

1. Mild Skeletal III, ability to achieve edge to edge incisors

2. Short vertical facial height (.Chincup cause clockwise rotation of the

mandible.

3. Proclined or upright LLS (Chincup cause lingual tipping of the lower incisors

(Thilander 1963)

4. Absence of severe facial and dental asymmetry


30

The effects of chincup therapy

(Thilander 1963)

Retardation of mandibular growth. Effective at reducing mandibular

prognathism before puberty but this is then lost with continual growth,

Sugawara et al., 1990

Remodelling of the condyle and glenoid fossa

Backward rotation of the mandible

Closure of the gonial angle

Result in lingual tipping of LLS,

Reverse chin cup therapy

1. Developed in Germany in 2012 by Rahman 2012 show

similar result when the reverse chin cup therapy compared to

face mask therapy in RCT involving 42 samples at age of 8- 9

years.

2. Reverse chin cup therapy is able to produce forward

movement of the maxilla in the growing child associated

with lingual tipping of the lower incisors and labial tipping of

the uppers.

3. The point of application of protraction elastics from the

upper removable appliances was similar for both groups. All patients received

the same protraction force of 500 g per side with a 30 degree downwards pull.

4. The proposed advantages of the new reverse chin cup design were that it was

smaller and less bulky than other protraction appliances, therefore encouraging

children to wear it.


31

Summary of the evidence

Dental effect,

1. Enmass retraction with HG plus extraction of the upper second molars

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

2. Atherton et al. (2002) came to the conclusion that the most distal movement

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

3. Firouz 1992 showed that the amount of intrusion achievable by HG is

0.5mm

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

displacement of the molars in patients wearing cervical headgear for an 8-

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

evaluated 7 years later

5. 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.

Skeletal changes

1. Mills 1978 in a review, stated a maxillary growth suppression effect of 1-2

mms is possible in humans with Kloehn bows

2. Wieslander, 1993,1mm of maxillary growth restraint achieved over a 10

year period that persists post-treatment

3. Tulloch et al 1997 (class II D1 OJ 7mm, HG, Bionato or CG for 15 months)

concluded that the bionator produced some mandibular change, whereas,

with the headgear, there was some maxillary restraint. In the TG (HG or

Bionator) the improvement in the ANB in 70-80% while no improvement in

20%. In the CG no improvement 50%, improvement 30% and worsening

20%.

4. Then Tulloch 1998 followed the patient and found that skeletal improvement


32

are lost after 1 year.

5. Keeling et al 1998 (HG/Biteplane, Bionator, CG, OJ 7mm for 2 years or

until class I achieved) suggested that a headgear biteplane combination

resulted in no restraint of the maxilla but forward positioning of the

mandible.

6. Ghafari et al 1998 suggested that headgear produces some maxillary

restraint and the Fränkel, mandibular growth increase.compliance

HG failure rate 5% for female and 25% for male (Ghafari 1998)

Intrusion of anterior teeth but less efficient than TADs (Degushi, 2008)

Hickman (1974) - devised a headgear which will accept 2 or even 3 "J"

hooks each side.

Root resorption. Linge and Linge 1983

Results in more movement on the side with the longer outer bow according

to Castagliano's Theorum

High-pull headgear at night, directed above the center 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).

Extraction of the upper second molars may be required bow and this claimed

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

Headgear to upper part of the Twin block , Park 2001used TB with HG and

torqueing spring and compared it to conventional TB and found that better

control of ULS inclination was with the first gp.

In a study by Wise et al (1994) which compared 20 non-extraction patients

in which a transpalatal bar was used for at least 5 months with similar

patients in whom it was not used, no significant differences were found

between the two groups.

Not all patients are honest in actual compliance. Using time charts can

increase co-operation (Cureton et al. 1992, 1993).

Contact dermatitis-type IV delayed hypersensitivity immune response ,Extraoral Orthodontic Appliances Mohammed Al-Muzian, University of Glasgow, 2013

33

(Rahilly and Price, 2003).

Four Types of Headgear Injuries in Europe, Samuels 1993 (23 countries

studied)

Ideal physical properties for the HG safety mechanism according to the

study of Stafford on 1998

Force affecting factors, Bowden 1978

Cureton et al. (1993) recommend the use of headgear charts routinely.

Recently the monitoring device like the Affirm headgear traction module has

been used (electronic timer)

Timing

1. Dental age: McNamara (1987) suggested that the optimal time for treatment

is in the early late mixed dentition, coincident with the eruption of the upper

permanent incisors.

2. Skeletal age: Baccetti et al (1998) showed that the early treatment group

CVM2 showed effective forward displacement of the maxillary structures

whereas the late treatment group CVM3 showed no change compared with

controls

3. Chronological age: Other investigators have suggested that for optimal

orthopaedic effects, treatment should be initiated before the patient is 9 years

old ( Proffit, 2000).

4. Kim et al., 1999, meta-analysis of effectiveness of protraction HG concluded

it was less effective on patients >10yrs

Evidence based short term effectiveness of PH, Mandall, 2010 (similar to

study of Ngan 1998)

Evidence based long term effectiveness of PH, Mandal 2012: Masucci 2011:

a removable full coverage acrylic splint is used with a protraction headgear

(Proffit 1986).

McNamara (1987) has described the use of a Biocryl and wire splint that is


34

bonded in the mouth.

Major (2012) in Canada, he found Approximately 3 mm of horizontal A-

point movement is predictably attainable with the skeletal one in comparison

to dental one

Rapid maxillary expansion Advantages (Haas 1973).

Many clinicians use protraction with a facemask following or

simultaneously with palatal expansion, because some evidence suggests that

the expansion makes antero-posterior skeletal change more likely. Kim et al

(1999)

There is other evidence that the expansion is optional and should be dictated

by the maxillary arch width related to the lower arch width, Vaughan 2005.

Ishii et al (1987) describe the effects of providing the protraction force from

the first molars or the premolar region. Protraction from the first molars

results in more anterior movement and a forward and upward rotation of the

maxilla; protraction from the premolars results in less forward movement

but less tendency to upward and forward rotation.

The idea of this appliance is that because the condyle is a growth site, the

growth impeded by extra-oral force (Graber, 1977).

Despite success in animal experiments, most human studies have found little

difference in mandibular dimensions between treated and untreated subjects

(Sugawara et al, 1990).

The effects of chincup therapy , (Thilander 1963)

Reverse chin cup therapy, Developed in Germany in 2012 by Rahman 2012

show similar result when the reverse chin cup therapy compared to face

mask therapy in RCT involving 42 samples at age of 8-9 year.

References

1. VLE, National orthodontic Programm

2. Excellence in Orthodontics,Extraoral Orthodontic Appliances Mohammed Al-Muzian, University of Glasgow, 2013

35

3. Postgraduate notes in orthodontics, 5th edition

4. Van Beek H. – Combination Headgear-Activator – JCO, March 1984.

5. Van Beek H. – Overjet Correction by a Combined Headgear and Activator –

EJO,4(1982) 279-290.

6. Orton H.S. – Functional Appliances in Orthodontic Treatment – An atlas of

clinical prescrption and laboratory construction – Quintessence Books, 1990.

7. Skeletal effects of early treatment of Class III malocclusions with maxillary

expansion and face-mask therapy Baccetti T et al (1998) AJODO 113: 333 –

343

8. The early management of Class III malocclusions using protraction headgear

Marcey-Dare LV (2000) Dental Update 27(10): 508-13

9. Biomechanical and clinical considerations of a modified protraction headgear

Nanda R (1980) AJO 78: 125 – 139

10.The management of Class III and Class III tendency malocclusions using

headgear to the mandibular dentition Orton HS (1983) BJO 10: 2 – 12

11.A philosophy of combined orthopedic-orthodontic treatment PfeifferJP &

Grobety D (1982) AJO 81: 185 – 201

12.Protraction of the cleft maxilla Ranta R (1988) EJO 10: 215 – 222

13.Bioprogressive therapy Ricketts et al (1979) Section 1 Part 5:Orthopaedics in

Bioprogressive therapy and Section 7 Part 7: Factors in headgear design and

application


36

14.Chin cup therapy for mandibular prognathism Graber LW (1977) AJO 72: 23 –

41.

15.The management of Class III and Class III tendency malocclusions using

headgear to the mandibular dentition Orton HS (1983) BJO 10: 2 – 12.

16.Effects of chin cup force on the timing and amount of mandibular growth

associated with Class III malocclusion Mitani et al (1986) AJO 90: 454 – 463.

17.Stability of changes associated with chin cup therapy Deguchi et al (1996)

Angle O 66: 139 – 145.

18.A Randomised linical Trial, Tulloch JFC, Phillips C, Koch and Proffit WR.

AJODO 1997; 111: 391-400

19.BOS advices,

http://www.bos.org.uk/OneStopCMS/Core/CrawlerResourceServer.aspx

20.Contemporary orthodontics, Fourth Edition, 2007


http://www.bos.org.uk/OneStopCMS/Core/CrawlerResourceServer.aspx

extra oral appliances by almuzian

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