PRESENTED BY:MD. ISHTIAQ HASANFCPS-II TRAINEE,DEPT. OF ORTHODONTICS, DDCH

SUPERVISOR:PROF. DR. MD. ZAKIR HOSSAINBDS, PHD(JAPAN)PROF. & HEAD,DEPT. OF ORTHODONTICS,DDCH.

PT NAME: FATEMA

AGE: 24 YRS

LEFT AND RIGHT PROFILE VIEW

CHIEF COMPLAIN: SPACING IN UPPER & LOW JAW

MODEL ANALYSIS

UPPERJAW : 12 mm SPACING

LOWERJAW: 10 mm SPACING

DIAGNOSIS

• It is a case of ant. open bite with spacing in upper and lower jaw .

TREATMENT PLAN

APPROXIMATE12 12

1212

THEN ?

ARCH CONTRACTION

OR

PROSTHESIS ?

NASO-LABIAL ANGLE

94°

Normal=102 +/- 8°

For each mm of incisor retraction, 1.6 ° increase of naso-labial angle.

LABIO-MENTAL ANGLE

123°

Normal=122+/- 11.7°

The lips will move two-thirds of the distance that the incisors are retracted , i.e. , 3 mm of incisor retraction will reduce lip protrusion by 2 mm , but only until competence is reached. Beyond that point , further retraction of the incisors will not further reduce lip prominence.

---------- PROFFIT

1 mm of lower incisor retraction resulting in 1 mm of lower lip retraction and on average, 3 mm of upper incisor retraction is needed for 1 mm of upper lip retraction.

--------BURSTONE

LETS TAKE A LOOK WHAT OTHER

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TREATMENT PLAN

OVERJET REDUCTION

The following four dental and skeletal non-surgical changes are responsible for overjet reduction----

Mesial movement of lower incisorsDistal movement of upper incisorsDistalizing or limiting forward growth of maxillaMesial movement of mandible by---(a)forward

mandibular growth or (b) limiting vertical development

The first two changes involve dental tooth movement , while the last two involve skeletal changes. In adult , non-growing patients , such skeletal changes must be carried out surgically.

Overjet reduction from mesial movement of lower incisors.

Overjet reduction from distal movement of upper incisors.

Overjet reduction from mesial movement of mandible resulting from condylar growth.

Overjet reduction from distalizing or limiting forward growth of maxilla.

Overjet reduction from mesial movement of mandible by limiting development.

Mesial movement of lower incisors

The end treatment position of lower incisors is important for several reasons ----

If lower incisors are too far back , then there is a tendency to a retrognathic profile and a long term deepening of overbite.

If the lower incisors are too far forward , then there is a undue fullness of facial profile and possibility of instability of lower labial segment ,as incisors drop back towards the tongue in response to lip pressure.

If the lower incisors are left too far back , there is a tendency to a retrognathic profile and a long term deepening of overbite.

If the lower incisors are left too forward , there is a tendency to undue fullness of the facial profile and possibility of instability of lower labial segment.

The ideal position of lower incisors should be 2 mm infront of APo line.

• At the end of treatment , there should be 90-95° angulations between lower incisors and mandibular plane.

• There is usually a soft tissue involvement when require mesial movement of lower incisors. For example , if there is a history of thumb sucking activity or hyperactive mentalis muscle function where lower incisors have been held back and retroclined. In these cases , it is mechanically appropriate to move the lower incisors forward.

• cl-II div 2 treatment sometimes involve the mesial movement of lower incisors. There is often soft tissue element to such cases , where the high lip line with lip activity has retroclined both upper and lower incisors.

During routine mechanics after the incisors have been moved forward to create a cl-II div 1 pattern with an overjet , it is frequently found that the lower incisors are back in the profile. It is then appropriate to tip the lower incisors forward .

Distal movement of upper incisors

• The ideal position of upper incisors should be 6 mm infront of APo line with an angulation of 110 ° to the maxillary plane

Traditionally distal movement of upper incisors has been regarded as the main method of correction of cl-II div1 malocclusion. However , since it has been shown that true maxillary protrusion occurs in only about 20% cases , changes involving mesial movement of chin point are preferable for facial profile reasons. In adults , this implies orthognathic surgery to the maxilla or the mandible.

• Where the commencing upper incisor angulation is above 115° , the initial retraction is often achieved by a tipping type of movement until normal angulation is reached , and then bodily movement is attempt.

Distal movement or limiting forward growth of maxilla

Assessment of the position of maxillary bone may be measured by---

the SNA angle favoured by Steiner and

Dropping a perpendicular line from Nasion to Frankfort plane and using a normal of 0 mm for A point , as recommended by McNamara.

• When it is clear that increased overjet is due to a forward position of maxillary bone , it is appropriate to attempt to use orthopedic headgear or class II elastics to influence maxillary growth in the growing individual. The distalization of the maxilla itself is difficult and require good co-operation with heavy orthopedic forces. Usually such forces to the maxilla will limit its forward growth , which would be approximately 1 mm per year in a growing child.

Mesial movement of the mandible • Normal position of

mandible is 4 mm behind the Nasion Frankfort perpendicular line (McNamara).

• Also SNB angle of 80° as recommended by Steiner can be used as a reference for horizontal mandibular position .

• Mesial movement of the mandible also can be achieved by limiting of vertical growth.

Any mechanical process which reduce or maintain the MM angle will producee mesial movement of pogonion in the facial profile. The use of high pull head gear , palatal bar , lingual arch and post bite plate favor control of this type. Also , the extraction of premolar teeth makes vertical control easier.

Use of inter-maxillary elastics in high angle cases, as well as, cervical headgear and ant. Bite plate tends to open the MM angle and produce unfavourable change in the position of pogonion. Non-extraction treatment also makes it difficult to prevent the MM angle opening.

MM angle tends to open in response to—• non-extraction treatment• cervical headgear• prolonged intermaxillary elastics• ant bite plateMM angle tends to close or be maintained in

response to---• extraction treatment• high pull headgear• palatal bar and lingual arches• post. Bite plate

In cl-II div 1 cases with increased MM angle , vertical control is important to reduce the angle or at least prevent it from increasing. Pogonion will move distally in the profile if MM angle is allowed to increase .

•In summery, an understanding of the importance of vertical factors is essential to proper management of overjet reduction.

THE MECHANICS OF OVERJET REDUCTION

There are primarily 3 methods used to correct cl-II molar relationship and reduce overjet---

Cl II elasticsHeadgearFunctional appliance

These 3 primary methods can be used separately or in combination and ultimately their correct use is the key to a successful result.

CLINICAL EXAMPLES

EXAMPLE A: Lower arch

contraction finished and the lower incisors are good position in the facial profile.

Upper incisors torque is correct

3 mm excess overjet to close

overbite is properly controlled

6 mm of upper extraction need to close

Molar relationship 3 mm cl-III

6 mm

3 mm3 mm

TREATMENT PLAN:

The remaining 6 mm of upper space may be closed by reciprocal space closure , using sliding mechanics , because molar relationship is cl-III. The molars and premolars will move mesially by 3 mm as the canines and incisore move distally by 3mm.

Night time head gear support can be use if the molars move forward more rapidly than anteriors.

The rectangular wire will allow bodily control of the upper incisors , provided force levels are light.

6 mm

3 mm3 mm

6 mm

3 mm 3 mm

EXAMPLE B:Lower incisors are in good position in facial profile

Upper incisor torque is correct

4 mm of excess overjet to reduce

molars are Cl-I

4 mm of upper extraction space to close.

4 mm

4 mm

TREATMENT PLAN:

The remaining space should not be closed by reciprocal space closure , because molar relation is cl-I and it will change into cl-II because molars and premolars will tend to move mesially as the canines and incisors moved distally.

Support from a sleeping head gear or a palatal bar is needed to protect the molar relationship during overjet reduction.

4 mm

4 mm

4 mm

4 mm

EXAMPLE C:

Lower arch space closure finished.

But lower incisors are set back by 2mm in facial profile

Upper incisor torque is correct

4 mm of upper extraction space need to close

4 mm of overjet need to be reduced

molar relationship Cl-I

4 mm

4 mm

TREATMENT NEED:

The remaining space can be closed by reciprocal space closure with Cl-II elastics which will protect the molar relationship by bringing the lower arch forward to a position close to APo +2mm.

In upper arch , the molars and premolars will move mesially by 2mm as the canines and incisors move distally by 2 mm.

Here MM angle is 28° (average) , so Cl-II elastics can be used.

INTERMAXILLARY ELASTIC IS CONTRAINDICATED IN HIGH ANGLE CASES.

A HIGH PULL HEADGEAR IS NORMALLY PREFERRED FOR UPPER MOLAR SUPPORT DURING OVERJET REDUCTION IN HIGH ANGLE CASES.

4 mm

4 mm

4 mm

4 mm

EXAMPLE D: Lower arch space

closure finished.

Lower incisor is good position in facial profile.

Upper incisor torque is not correct , they are proclined at 122°

7 mm of overjet to reduce

7 mm of upper extraction space to close

Molars are Cl-I

7 mm

7 mm

TREATMENT PLAN:

The remaining space should not be closed by reciprocal space closure as Cl-I molar relationship will be lost.

Excess 10° tipping can be corrected by round wire first , then rectangular wire can be used for bodily movement.

If a large overjet needs to be closed , rectangular wire is essential and support from a sleeping headgear or palatal bar will definitely needed, otherwise molars will come forward and molar relationship will lost.Also force level should be low.

7 mm

7 mm

EFFECT OF TOO RAPID SPACE CLOSURE----

Reduced torque control when space closure more than 1.5 mm/month

Rapid mesial movement of upper molar followed by palatal cusp hang down.

Lateral open bite Soft tissue hyperplasia at extraction site.

7 mm

7 mm

EXAMPLE E:

Lower arch appear to be finished

Lower incisors set back in the facial profile

Upper incisors torque is correct

3 mm excess overjet to correct

Molars are 2 mm Cl-II

3 mm2 mm

TREATMENT PLAN: Tieback are placed to hold the upper and

lower spaces closed.

3 mm of overjet may be reduced by Cl-II elastics , as MM angle is average (28°)

The upper arch act as an anchorage unit with teeth ligated to a rectangular wire.

The lower incisors are at 89° and can therefore be allowed to tip forward by upto 6°

As the overjet reduces , the lower teeth move mesially and molar move in Cl-I relationship

The tips of the lower incisors can be expected to move mesially more than the lower molars do (3 mm compared to 2 mm) , because part of the incisor closure involve tipping. The lower rectangular wire can carry a little labial crown torque in the incisor region to assist forward tipping of incisors.

EVERY 2.5° PROCLINATION , MOVES THE LOWER INCISOR EDGE FORWARD BY 1 MM

(RESULTING IN SPACE GAINS OF 2 MM FOR EVERY 2.5° OF PROCLINATION).

3 mm2 mm

3 mm2 mm

EXAMPLE F:

Cl-II div 1 cases with extraction of all four bicuspids.

3 mm of lower extraction space need to close.

4 mm of upper extraction space need to close

4 mm of overjet need to closeMolars are 3 mm Cl-II

4 mm

4 mm

3 mm

3 mm

TREATMENT PLAN: 4 mm of overjet may be reduced by

Cl-II elastics as MM angle is average (28°)

Sleeping hadgear is necessary , otherwise upper molar will come anteriorly.

Cl-II elastics causes lower molars and premolars to move mesially , thus helping 3 mm of lower extraction space closure and 3 mm of molar relationship to be corrected.

Month by month monitoring is needed and good patient co-operation is needed.

Upper second molar should be included.

4 mm

4 mm

3 mm

3 mm

4 mm

4 mm

3 mm

3 mm

EXAMPLE G:Cases with extraction of all 4 bicuspids

Lower incisors are 2 mm forward position than ideal position

4 mm of overjet to reduce

4 mm of upper and lower extraction space to close

Molars are 4 mm Cl-II

4 mm

4 mm

4 mm

4 mm

TREATMENT PLAN:

• cl-II elastic can not be used as it is a high angle case.

• upper labial segment move distally by 6 mm

• headgear support is needed for 2 mm upper molar distalization

• lower space closure will need to be reciprocal , with molar traveling mesially by 2 mm and incisors going distally by 2 mm

4 mm

4 mm

4 mm

4 mm

4 mm

4 mm4 mm

4 mm

EXAMPLE H: Non-extraction

case Lower incisors set

back 1 mm in facial profile

Upper incisors torque is correct

3 mm overjet to reduce

Molars are 3 mm Cl-II

3 mm3 mm

TREATMENT PLAN :

Only a reduced amount od Cl-II elastic traction is needed to reduce the overjet and headgear support to the upper first molar is essential for distalization of 2 mm.

A headgear during sleeping and Cl-II elastics during the day time can be used. This will give a 24 hour distalizing force on the upper arch and only a 12 hours of mesializing force on lower molars.

The lower rectangular wire has additional lingual crown torque in the incisor region to resist forward tipping movement of the incisors. Lower teeth should be ligated hard.

3 mm3 mm

3 mm 3 mm

EXAMPLE I: Cl-II div 1 malocclusion

Molar 7 mm Cl-II

OJ 7 mm

7 mm7 mm

TREATMENT PLAN:

Cervical pull headgear on upper arch for 14 hours per day , usually when pt is at home and sleeping

Cl-II elastics with an upper sliding jig for 10 hours per day

After 6 mm of molar distalization , upper cuspids and bicuspids are bracketed

Headgear continue to wear 14 hours per day to initiate overjet reduction

During day time, 10 hours of Cl-II elastics are worn to the hooks on archwire rather than to the sliding jig to complete overjet reduction

A 24 hour of force is applied to the upper arch to complete the molar relationship first & then to complete overjet reduction & only an intermittent force of 10 hrs per day is applied to the lower arch with Cl-II elastics

7 mm7 mm

8

7

6

5

• NEITHER FULL ARCH CONTRACTION NOR PROSTHESIS

THE MORE VERTICAL THE UPPER INCISORS ARE, THE MORE TORQUE IS NEEDED.

BEFOREAFTER

BEFORE AFTER

NASO-LABIAL ANGLE

94°

Normal=102 +/- 8°

104°

BEFORE AFTER

MENTO-LABIAL ANGLE

137°

BEFORE AFTER

123°

Normal=122+/- 11.7°