Tweed merrifield /certified fixed orthodontic courses by Indian dental academy

TWEED- MERRIFIELD
EDGEWISE
PHILOSOPHY
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com


CONTENTS
 HISTORY

OF EVOLUTION
 ANGLE’S PHILOSOPHY
 TWEED PHILOSOPHY
 TWEED – MERRIFIELD PHILOSOPHY
 APPLICATION OF PHILOSOPHY INTO
PRACTICE
 CONCLUSION

ANGLE- TWEED- MERRIFIELD
LEGACY


EDWARD HARTLEY ANGLE


E ARCH APPLIANCE

PIN AND TUBE APPLIANCE

RIBBON ARCH APPLIANCE

EDGEWISE APPLIANCE

EDGEWISE
OPENFACE
TIE BRACKETS

EVOLUTION OF THE
EDGEWISE
CONCEPT


ANGLE’S CONCEPT OF AN APPLIANCE
SIMPLE- PUSH, PULL, ROTATIONS
 STABLE - FIXED TO TEETH
 EFFICIENT- PROVIDE ANCHORAGE
 DELICATE - ACCEPTED BY TISSUES
 INCONSPICUOUS - ESTHETIC



THE RIBBON ARCH WAS NOT CAPABLE
OF AN EN MASSE TOOTH MOVEMENT.
HENCE THIS BECAME HIS MOTIVATION.
THE EDGEWISE BRACKET CAME INTO
EXISTENCE IN 1925.THE BRACKET
SLOT WAS PLACED HORIZONTALLY
WITH A RECTANGULAR SLOT HAVING
A .022 BY .028 INCH DIMENSION.


THE ARCHWIRE WAS HELD IN POSITION
FIRST BY A BRASS LIGATURE AND LATER
BY DELICATE STAINLESS STEEL
LIGATURE.THE ARCHWIRE WAS GOLD
ARCHWIRE.
THE NEW DESIGN PROVIDED MORE
ACCURACY AND A MORE EFFICIENT
TORQUING MECHANISM.

ANGLE’S EDGEWISE PHILOSOPHY
INCORPORATED THE
NON-EXTRACTION PROTOCOL
THEREFORE CLOSING OF SPACES IN
THE POSTERIOR SEGMENTS WAS A
PROBLEM.
ANTEROPOSTERIOR CORRECTION
DIFFICULT TO ACCOMPLISH.
PROCLINATION OF ANTERIOR TEETH
WAS COMMON.
CROWNS TENDED TO TIP MESIALLY.

ANGLE SUGGESTED THAT AS LONG AS
THE APPLIANCE WAS UTILISED TO ITS
MAXIMUM POTENTIAL…….
MILD PROCLINATION IS INEVITABLE AND
SHOULD NOT BE A CAUSE OF DISTRESS.
ANTERO POSTERIOR PROBLEMS COULD
BE RECTIFIED BY TIPPING THE CROWNS
DISTALLY.

ANGLE FOUND A CAPABLE MAN IN
CHARLES TWEED TO CONTINUE WHERE
HE HAD LEFT .
HENCE THE LEGACY OF THE EDGEWISE
APPLIANCE PASSED OVER FROM
ANGLE TO TWEED WITH THESE LAST
WORDS..
‘ I HAVE FINISHED MY WORK,IT
IS AS PERFECT AS I CAN MAKE IT.’

TWEED
PHILOSOPHY


CHARLES H.TWEED

TWEED WOULD OVER THE COURSE OF
TIME REVOLUTIONISE EDGEWISE
PHILOSOPHY IN A MOST RADICAL WAY.
ALTHOUGH INITIALLY CALLED THE
‘TRAITOR OF ANGLE’, BY HIS
ADVOCACY OF FIRST PREMOLAR
EXTRACTIONS WHICH WAS DEEMED A
HERESY BACK THEN……..

HE BECAME A LEGACY FOR ALL TO
FOLLOW WITH HIS CONCEPT OF:
 EXTRACTIONS
 UPRIGHTING

OF TEETH OVER BASAL

BONE.
 APPLICATION OF CEPHALOMETRICS.
 DIAGNOSTIC FACIAL TRIANGLE.
 ANCHORAGE PREPARATION.
 SERIAL EXTRACTION IN MIXED
DENTITION.
 GROWTH TRENDS

DIAGNOSTIC FACIAL TRIANGLE


FOUR ESSENTIAL ANGLES CONSIDERED
FRANKFORT MANDIBULAR PLANE ANGLE
OR FMA ( 25 DEGREES)
 MANDIBULAR INCISOR PLANE ANGLE OR
IMPA ( 90 DEGREES)
 FRANKFORT MANDIBULAR INCISOR ANGLE
OR FMIA (65 DEGREES)
 POINT A – NASION – POINT B OR ANB( O
TO 5 DEGREES)



ANCHORAGE PREPARATION
FIRST DEGREE ANCHORAGE PREPARATION
ANCHORAGE PREPARATION NOT CRITICAL
WHEN ANB RANGES FROM 0 TO 4 DEGREES
AND FACIAL ESTHETICS IS GOOD.
TERMINAL MANDIBULAR MOLARS MUST BE
JUST UPRIGHT TO PREVENT ELONGATION
BY CLASS II ELASTICS.


SECOND DEGREE ANCHORAGE
PREPARATION
ANCHORAGE PREPARATION NECESSARY
AS ANB IS ABOVE 4.5 DEGREES AND
FACIAL ESTHETICS NOT GOOD.
DISTAL RIDGE OF TERMINAL MOLARS
MUST BE TIPPED TO GUM LEVEL AND
DIRECTION OF CLASS II ELASTICS MUST
BE GREATER THAN 90 DEGREES SO AS TO
FURTHER DEPRESS IT.

THIRD DEGREE OR TOTAL
ANB NOT GREATER THAN 5 DEGREES
AND BIMAXILLARY PROTRUSION.
DISTAL TIPPING OF TERMINAL SECOND
MOLARS TO BELOW GUM LEVEL.FIRST
MOLARS AND SECOND PREMOLARS
ALSO DISTALLY TIPPED TO AUGMENT
ANCHORAGE.

GROWTH TRENDS
TYPE A GROWTH TREND
 CHARACTERISED

BY MIDDLE AND
LOWER FACE GROWING DOWNWARD
IN UNISON WITH NO CHANGE IN ANB.
 IF ANB NOT MORE THAN 4.5
DEGREES,NO TREATMENT
INDICATED.

TYPE A SUBDIVISION
MOLAR RELATIONSHIP CLASS II WITH
ANB GREATER THAN 4.5 DEGREES.
 RESTRAIN MAXILLARY GROWTH WITH
KLOEHN HEADGEAR .
 PROGNOSIS IS GOOD.
 TREATMENT COMPLETED IN 15 TO 21
MONTHS.



TYPE B GROWTH TREND
 ANB

6 TO 12 DEGREES
 MIDDLE FACIAL HEIGHT GROWTH
FASTER THAN LOWER FACIAL
HEIGHT.
 PROGNOSIS POOR.
 ALL FOUR FIRST PREMOLAR
EXTRACTION AND KLOEHN
HEADGEAR
 TREATMENT TIME 36 TO 42 MONTHS.

TYPE C GROWTH TREND
 LOWER

FACE GROWS FASTER THAN
MIDDLE FACE.
 MANDIBULAR INCISOR LINGUAL
TIPPING OR MAXILLARY INCISOR
LABIAL FLARING CAN OCCUR.
 CUSPID TO CUSPID LINGUAL BAR
WITH MAXILLARY RETAINER GIVEN.
 PROGNOSIS EXCELLENT
 TREATMENT TIME 10 TO 15 MONTHS.

TYPE C SUBDIVISON
 WHEN

GROWTH IS PREDOMINANTLY
HORIZONTAL WITH A DECREASED
FMA ANGLE.
 LITTLE VERTICAL GROWTH OCCURS.


HIS PHILOSOPHY INCORPORATED:
 POSITION

AND ARRANGE TEETH FOR
MAXIMAL FACIAL AND DENTAL
ESTHETICS AND FUNCTIONAL
EFFICIENCY.
 HEALTH OF
TEETH,JAWS,JOINTS,SURROUNDING
TISSUES MUST BE MAINTAINED.
 STABLITY
 HARMONISE CORRECTION OF
NORMAL GROWTH PROCESSES.

 MAXIMISE

COMPENSATION FOR LESS
THAN NORMAL GROWTH PATTERNS.

 POSITION

THE DENTITION SO THAT IT
IS IN A CONTINUAL STATE OF
HARMONY WITH ITS ENVIRONMENT.


DRAWBACKS OF THE TWEED
PHILOSOPHY


 HE

CONCENTRATED ON THE ANTEROPOSTERIOR AND VERTICAL TREND OF
GROWTH ON THE BASIS OF WHICH HE
FORMULATED THE GROWTH TRENDS.

 EN

MASSE TOOTH MOVEMENT DID
NOT NECESSARILY TRANSLATE INTO
PRECISON AND CONTROL.


 MANDIBULAR

ANCHORAGE WAS
PREPARED WITH CLASS III ELASTICS
AND WITH ALL COMPENSATION
BENDS PLACED IN ARCH WIRE AT
ONE TIME RESULTING IN LABIALLY
FLARED AND INTRUDED MANDIBULAR
INCISORS AS A SEQUELAE.


TWEED NAMED LEVERN MERRIFIELD
AS HIS SUCCESSOR TO GUIDE THE
RAPIDLY EXPANDING AND
SUCCESSFUL TWEED STUDY COURSE
IN TUCSON , ARIZONA.
THE PITFALLS OF THE TWEED PHILOSOPHY
WHERE TO BE RECTIFIED BY HIM AND
WAS SUBSEQUENTLY KNOWN AS THE
‘ TWEED-MERRIFIELD PHILOSOPHY’

TWEED- MERRIFIELD
PHILOSOPHY


LEVERN MERRIFIELD

MERRIFIELD INTRODUCED THE
TWEED MERRIFIELD PHILOSOPHY BY
ADDING A SEVENTH OBJECTIVE
 ALL

CLINICAL OBJECTIVES MUST BE
PURSUED IN AN ETHICAL ,MORAL
AND COMPASSIONATE MANNER WITH
AN OVER RIDING CONCERN FOR THE
PUBLIC’S WELFARE.


THE TWEED MERRIFIELD IS BASED ON FOUR
FUNDAMENTAL PILLARS OR
PREMISES. THEY ARE:
AN ANTERIOR LIMIT EXISTS.THE TEETH
MUST NOT BE PLACED FORWARD OF
BASAL BONE.
 A POSTERIOR LIMIT EXISTS.
 A LATERAL LIMIT EXISTS. ANY POSITION
BEYOND THIS RESULTS IN
A RELAPSE.
 A VERTICAL LIMIT EXISTS. FACIAL BALANCE
AND HARMONY CAN BE LOST AS RESULT.



BROAD PARAMETERS OF THE TWEEDMERRIFIELD PHILOSOPHY INCLUDE:
 ASSESSING

THE DIMENSIONS OF THE
LOWER FACE.
 TOTAL SPACE ANALYSIS.
 ASSESSING AREAS OF
SKELETAL,FACIAL AND DENTAL
DISHARMONY.
 DIRECTIONAL CONTROL DURING
TREATMENT

 SEQUENTIAL

TOOTH MOVEMENT.

 SEQUENTIAL

MANDIBULAR
ANCHORAGE PREPARATION.


DIFFERENTIAL DIAGNOSIS

 FACIAL

DISHARMONIES
 DENTAL DISHARMONIES
 CRANIAL DISHARMONIES
 ENVIRONMENTAL DISHARMONIES


FACIAL DISHARMONIES
THREE FUNDAMENTAL FACTORS
INFLUENCE FACIAL BALANCE:
 POSITONS

OF TEETH
 SKELETAL PATTERN
 SOFT TISSUE THICKNESS


 TOOTH

POSITON PLAYS A
FUNDAMENTAL ROLE IN FACIAL
BALANCE.
 MAXILLARY INCISOR POSITION IS
DIRECTLY RELATED TO POSITION OF
MANDIBULAR INCISORS.
THIS CAN BE DIAGNOSED BY
EQUATING THE UPPER LIP
MEASUREMENT TO THAT OF THE
LOWER CHIN.

UPPER LIP THICKNESS IS MEASURED
FROM THE GREATEST CURVATURE
OF THE LABIAL SURFACE OF THE
CENTRAL INCISOR TO VERMILION
BORDER OF UPPER LIP.
TOTAL CHIN THICKNESS IS
MEASURED HORIZONTALLY FROM NB
LINE EXTENDED TO SOFT TISSUE
POGONION.

UPPER LIP = TOTAL CHIN

TWO ANGLES ARE USED TO
QUANTIFY FACIAL BALANCE:
Z ANGLE
IDEALLY THE Z LINE MUST BE
TANGENT TO THE CHIN AND THE
VERMILION BORDER OF BOTH LIPS
AND SHOULD BISECT THE NOSE.IT
SHOULD PROCEED TO JOIN THE
FRANKFORT PLANE AT AN ANGLE
OF 75 TO 78 DEGREES.

FMIA ANGLE
THE FMIA SHOULD CORRESPOND TO
AN ANGLE OF 65 DEGREES .


A BALANCED FACE CORRESPONDING TO Z ANGLE AND
FMIA ANGLE

CRANIAL DISHARMONIES
THE FOLLOWING READINGS WERE
TAKEN INTO ACCOUNT TO ASSESS
CRANIAL DISHARMONIES :
 SNA

: 80- 84 DEGREES
 SNB : 78- 82 DEGREES
 ANB : 1- 5
DEGREES
 AO- BO : 0-4 MM

 OCCLUSAL

PLANE TO FRANKFORT
HORIZONTAL PLANE : 8- 12 DEGREES
 FACIAL HEIGHT INDEX
PFH X 100 = 69% OF AFH.
AFH
A RANGE OF 65 TO 75% WAS FOUND
TO BE ACCEPTABLE.

FACIAL HEIGHT CHANGE RATIO:
FACIAL HEIGHT CHANGE WAS
ASSESSED DURING THE COURSE OF
TREATMENT.
A RATIO OF TWO TIMES AS MUCH PFH
INCREASE THAN AFH INCREASE
DURING TREATMENT WAS IDEAL FOR
CORRECTION OF CLASS II DIV 1 AND
DENTOALVEOLAR PROTRUSIONS.

DENTAL DISHARMONIES
TOTAL SPACE ANALYSIS
DIVIDED INTO THREE PARTS:
 ANTERIOR
 MIDARCH
 POSTERIOR

ANTERIOR SPACE ANALYSIS
MEASUREMENT TAKEN FROM MANDIBULAR
CANINE TO CANINE.ALSO MESIODISTAL
DIAMETER OF SIX ANTERIOR TEETH TAKEN.
THE DIFFERENCE GIVES IDEA OF SURPLUS
OR DEFICIT.
 LATERAL HEAD FILM DISCREPANCY TAKEN
INTO ACCOUNT.IT IS THE AMOUNT OF
SPACE REQUIRED TO POSITION THE
MANDIBULAR INCISORS FOR FACIAL
BALANCE.
 TOTAL CHIN THICKNESS MUST EQUAL
UPPER LIP THICKNESS.HENCE SOFT
TISSUE BALANCE OBTAINED.



THUS THE SUM OF ANTERIOR TOOTH
ARCH SURPLUS OR DEFICIT,LATERAL
HEADFILM DISCREPANCY AND SOFT
TISSUE IMBALANCE IS COMBINED TO
ESTIMATE THE ANTERIOR
DISCREPANCY.
EACH OF THE VALUES IS ASSIGNED A
DIFFICULTY FACTOR.


MIDARCH SPACE ANALYSIS
 INCLUDES

MANDIBULAR FIRST
MOLARS AND FIRST AND SECOND
PREMOLARS.
 AVAILABLE MIDARCH SPACE: DISTAL
OF CANINE TO DISTAL OF FIRST
MOLAR.TO THIS ADD THE SPACE
REQUIRED TO LEVEL THE CURVE OF
SPEE.

 OCCLUSAL

DISHARMONY:
ARTICULATE THE CASTS AND USE
MAXILLARY FIRST PREMOLAR AS
REFERENCE.MEASURE MESIALLY OR
DISTALLY FROM BUCCAL CUSP OF
MAXILLARY FIRST PREMOLAR TO
EMBRASURE BETWEEN MANDIBULAR
FIRST AND SECOND
PREMOLARS.MEASUREMENT DONE
ON BOTH SIDES AND AVERAGED.THE
AVERAGED VALUE IS THEN DOUBLED
AND ADDED TO MIDARCH DIFFICULTY.

POSTERIOR SPACE ANALYSIS
MEASURED FROM THE DISTAL OF
MANDIBULAR FIRST MOLAR TO
ANTERIOR BORDER OF RAMUS
ALONG THE OCCLUSAL PLANE.
THIS MEASUREMENT MUST TAKE
INTO CONSIDERATION THE AGE AND
GENDER OF THE PATIENT AS WELL.

VARIABLES TO BE TAKEN INTO
ACCOUNT WHEN ASSESSING
POSTERIOR SPACE ARE:
 RATE

OF MESIO-OCCLUSAL
MIGRATION OF MANDIBULAR FIRST
MOLAR.
 RATE OF RESORPTION OF ANTERIOR
BORDER OF RAMUS.
 TIME OF CESSATION OF MOLAR
MIGRATION.

 TIME

OF CESSATION OF RAMUS
RESORPTION.
 GENDER
 AGE.


APPLICATION OF
PHILOSOPHY INTO
PRACTICE


THE TWEED MERRIFIELD APPLIANCE IS
ESSENTIALLY CONSISTS OF .022
EDGEWISE SLOTS WITH
 DOUBLE WIDTH BRACKETS ON THE
SIX ANTERIOR TEETH.
 INTERMEDIATE SINGLE WIDTH
BRACKETS ON PREMOLARS.
 TWIN BRACKETS ON THE FIRST
MOLARS.
 .022 TUBES WITH MESIAL HOOKS ON
THE SECOND MOLARS.

TWEED MERRIFIELD EDGEWISE APPLIANCE


 TWEED

INITALLY USED 12 SETS OF
ARCHWIRES.MERRIFIELD REDUCED IT
TO FOUR TO FIVE SETS OF ARCH
WIRES
THE DIMENSIONS OF WIRE
COMMONLY USED WERE :
 .017X .022
 .018X .025
 .019X .025
 .020X .025
 .021X .028

FIVE CONCEPTS OF
TREATMENT PHILOSOPHY
 SEQUENTIAL

BANDING OR BONDING.
 SEQUENTIAL TOOTH MOVEMENT.
 SEQUENTIAL MANDIBULAR
 DIRECTIONAL FORCE APPLICATION.
 PROPER TIMING OF TREATMENT.


SEQUENTIAL BANDING OR
BONDING
THE TERMINAL MOLARS ARE
BANDED,THE SECOND PREMOLARS AND
CANINES.INCISORS CAN BE EITHER
BANDED OR BONDED.
ADVANTAGES :
 LESS TRAUMATIC TO PATIENT.
 EASIER AND LESS TIME CONSUMING
FOR THE ORTHODONTIST

LONGER INTERBRACKET LENGTH FOR THE
ARCHWIRE.HENCE CREATES A POWER
STORAGE IN THE WIRE THAT
ACCOMPLISHES THE OBJECTIVES RAPIDLY.
 ORTHODONTIST CAN INSERT A WIRE OF
LARGER DIMENSION THAT IS LESS
SUBJECT TO BRACKET ENGAGEMENT
DISTORTION.


MAXILLARY MOLARS ARE BANDED AFTER
ONE MONTH.THE MANDIBULAR
MOLARS AFTER SECOND VISIT.LATER
LATERAL INCISORS CAN BE BANDED OR
BONDED DEPENDING ON PROGRESS.

SEQUENTIAL TOOTH
MOVEMENT
 EN

MASSE TOOTH MOVEMENT NOT
DONE.
 TEETH MOVED INDIVIDUALLY OR IN
SMALL UNITS.
ADVANTAGES :
 MORE RAPID TOOTH MOVEMENT.
 MORE PRECISION INVOLVED.

SEQUENTIAL MANDIBULAR
INSTEAD OF CLASS III ELASTICS TWEED
OPTED FOR HIGH PULL GEAR FOR
 THE 10-2 SYSTEM WAS INCORPORATED TO
BETTER AUGMENT ANCHORAGE. TEN
TEETH WERE USED AS ANCHORS TO TIP
TWO TEETH.
ADVANTAGE:
 NO LABIAL FLARING OF MANDIBULAR
INCISORS.
 NO INTRUSION.



DIRECTIONAL FORCES
THIS CONCEPT LED TO THE
EVOLUTION OF MERRIFIELD’S
‘ SEQUENTIAL DIRECTIONAL FORCE
TECHNOLOGY’
DIRECTIONAL FORCES ARE DEFINED
AS CONTROLLED FORCES WHICH
PLACE THE TEETH IN THE MOST
HARMONIOUS RELATIONSHIP WITH
THEIR ENVIRONMENT.

THE RESULTANT VECTOR OF ALL FORCE
SYSTEMS MUST BE UPWARD AND
FORWARD SO THAT THE OPPURTUNITY
TFOR FAVOURABLE SKELETAL CHANGE IS
ENHANCED.
 SUCH A SYSTEM REAUIRES THAT THE
MANDIBULAR INCISOR BE UPRIGHT OVER
THE BASAL BONE SO THAT THE MAXILLARY
INCISOR CAN BE MOVED DISTALLY AND
SUPERIORLY.
 FOR THIS TO BE A REALITY, VERTICAL
CONTROL IS CRITICAL.



SEQUENTIAL DIRECTIONAL FORCE

TIMING OF TREATMENT
TREATMENT MUST BE INITIATED AT A TIME
WHEN THE TREATMENT OBJECTIVES CAN
BE READILY ACCOMPLISHED.
 INTERCEPTIVE TREATMENT IN MIXED
DENTITION
 SERIAL EXTRACTIONS IN MIXED DENTITION
 WAITING FOR SECOND MOLAR ERUPTION
DIAGNOSTIC DISCRETION IS PARAMOUNT.

INCORPORATION OF FORCE
SYSTEMS INTO THE PHILOSOPHY


FIRST ORDER BENDS


 THESE

BENDS PROVIDE FOR BUCCOLINGUAL MOVEMENTS OF TEETH
 BENDS ARE INCORPORATED IN THE
HORIZONTAL PLANE .
 THESE

BENDS PROVIDE FOR
EXPANSION OR CONTRACTION OF
THE ARCH AS THE NEED ARISES.


SECOND ORDER BENDS


THESE BENDS PROVIDE FOR MESIO-DISTAL
TIPPING OF TEETH AS AND WHEN
REQUIRED.
 BENDS ARE INCORPORATED IN THE ARCH
WIRE IN THE VERTICAL PLANE AS TIP- BACK
BENDS.
 BENDS MADE IN THE POSTERIOR SEGMENT
OF THE MANDIBULAR ARCH ARE
ANTAGONISTIC TO ANTERIOR TEETH
 LABIAL FLARING AND INTRUSION ARE THE
SEQUELAE IF ALL BENDS ARE PLACED AT
ONE GO.



 SECOND

ORDER BENDS MADE IN THE
POSTERIOR SEGMENT OF THE
MAXILLARY ARCH ARE
COMPLIMENTARY TO THAT OF
ANTERIOR SEGMENT.

 INTRUSION

AND LINGUAL ROOT
TORQUE OCCUR ON THE MAXILLARY
INCISORS .


THIRD ORDER BENDS


 THIRD

ORDER BENDS ARE GIVEN TO
EFFECT ROOT TORQUE,BE IT BUCCAL
OR LINGUAL.
 TWO RIBBON ARCH PLIERS ARE
UTILISED.ONE TO HOLD THE
WIRE.THE OTHER TO INCORPORATE
THE DESIRED TORQUE.
 IN THE MANDIBULAR
ARCH,INCORPORATION OF TORQUE
IS COMPLIMENTARY TO THE
ANTERIOR AND POSTERIOR
SEGMENTS



IN THE MAXILLARY ARCH,THIRD ORDER
BENDS PROVE TO BE ANTAGONISTIC AS
LITTLE OR NO TORQUE IS REQUIRED IN
THE ANTERIOR SEGMENT AND HENCE ANY
TORQUE IN THIS REGION IS UNDESIRABLE
WHEN TORQUE GIVEN IN POSTERIOR
SEGMENTS.



THEREFORE ACTIVE THIRD ORDER BENDS
ARE GIVEN IN POSTERIOR SEGMENTS
SEQUENTIALLY AND ONLY IN ONE
DIRECTION AT ANY GIVEN TIME.

FORCE SYSTEMS
 DENTURE

PREPARATION
 DENTURE CORRECTION
 DENTURE COMPLETION
 DENTURE RECOVERY


DENTURE PREPARATION
OBJECTIVES
 LEVELING
 INDIVIDUAL

TOOTH MOVEMENT AND
ROTATION CORRECTION
 RETRACTION OF BOTH MAXILLARY
AND MANDIBULAR CANINES.
 PREPARATION OF TERMINAL MOLARS
FOR STRESS RESISTANCE.

 THIS

STAGE REQUIRES
APPROXIMATELY SIX MONTHS.
 .017X.022 MAXILLARY ARCH WIRE.
 .018X.025 MANDIBULAR ARCH WIRE.
 LOOP STOPS MUST BE FLUSH WITH
THE SECOND MOLAR TUBES.
 MANDIBULAR SECOND MOLAR
RECEIVES A 15 DEGREE EFFECTIVE
DISTAL TIP.
 MAXILLARY SECOND MOLAR
RECEIVES 5 DEGREE DISTAL TIP
FROM WIRE DISTAL TO LOOP.

 HIGH

PULL HEADGEAR
INCORPORATED TO RETRACT THE
CANINES.
ADVERSE EFFECT: CANINES TEND TO
EXPAND OUT OF THE ALVEOLAR
TROUGH AS THEY GET RETRACTED.
REMEDY: PLACE A SECOND
PREMOLAR OFFSET BEND MESIAL TO
SECOND PREMOLAR BRACKET.
 AS CANINES RETRACT AND ARCHES
LEVEL,LATERAL INCISORS CAN BE
BANDED OR BONDED.

 POWER

CHAIN FORCE CAN BE USED
TO AID RETRACTION OF CANINES.

AT END OF DENTURE PREPARATION
 ALL DENTITION MUST BE FULLY
BRACKETED AND LEVELLED.
 CANINES SHOULD BE RETRACTED.
 ALL ROTATIONS CORRECTED.
 MANDIBULAR TERMINAL MOLARS
MUST BE TIPPED TO TERMINAL
ANCHORAGE POSITION.

DENTURE CORRECTION
 CONTINUATION

OF SEQUENTIAL
MANDIBULAR ANCHORAGE
PREPARATION.

 THE

CLASS II FORCE SYSTEM.


SPACES CLOSED WITH MAXILLARY AND
MANDIBULAR CLOSING LOOPS SUPPORTED
BY J HOOK HEADGEAR ATTACHED TO
HOOKS SOLDERED BETWEEN MAXILLARY
AND MANDIBULAR CENTRAL INCISORS.
ARCH WIRE CHANGES
 MAXILLARY: .020X.025 WITH 6.5MM
VERTICAL LOOPS.
 MANDIBULAR: .019X.025 WITH 6MM
VERTICAL LOOPS.




LOOP STOPS IMMEDIATELY DISTAL
TO BRACKETS OF FIRST MOLARS.

 LOOP

STOP IN MANDIBULAR
ARCHWIRE INCORPORATES
COMPENSATION TO MAINTAIN 15
DEGREE MOLAR TIP.


END OBJECTIVES PRIOR TO
PREPARATION WOULD BE :
 OBTAIN

SPACE CLOSURE IN BOTH
ARCHES.
 MAINTAIN CURVE OF OCCLUSION IN
MAXILLARY ARCH.
 LEVEL MANDIBULAR ARCH.
 MAINTAIN 15 DEGREE DISTAL TIP OF
SECOND MOLAR.

SEQUENTIAL MANDIBULAR
ARCH PREPARATION
 EMPLOYS

A 10-2 ANCHORAGE

SYSTEM.
ADVANTAGES:
 QUICK CONTROLLED RESPONSE
 SUPPORTED BY HIGH PULL HEAD
GEAR WORN ON VERTICAL SPURS
SOLDERED DISTAL TO MANDIBULAR
LATERAL INCISORS.

AFTER CHECKING THAT :
 THE MANDIBULAR ARCH IS LEVEL.
 THE SECOND MOLARSARE TIPPED TO
A 15 DEGREE ANGULATION.
A READOUT IS OBTAINED WHEREBY
THE MANDIBULAR ARCHWIRE IS
REMOVED AND A PLAIN ARCHWIRE IS
INSERTED INTO THE SECOND MOLAR
TUBE AND A READOUT IS OBTAINED.

READ OUT

THE SECOND STEP OF SEQUENTIAL
MANDIBULAR PREPARATION IS NOW
INITIATED.
 ANOTHER

.O19X .025 ARCHWIRE IS
FABRICATED WITH LOOP STOPS BENT
FLUSH AGAINST SECOND MOLAR
TUBES.
 HEADGEAR HOOKS SOLDERED
DISTAL TO LATERAL INCISORS.

10 DEGREE DISTAL TIP PLACED 1MM
MESIAL TO FIRST PREMOLAR BRACKETS.
 A COMPENSATING BEND PLACED TO
MAINTAIN 15 DEGREE TIP AT TERMINAL
MOLAR.
 THUS ARCHWIRE IS PASSIVE TO SECOND
MOLAR AND CROSSES FIRST MOLAR AT A
10 DEGREE ANGLE.
 THE SECOND MOLAR BECOME PART OF
STABILISING UNIT.FIRST MOLAR IS THE
RECIPIENT OF DIRECTIONAL FORCES.
 FOR IDEAL RESPONSE A HIGH PULL
HEADGEAR APPLIED TO ANTERIOR
VERTICAL SPURS.



FIRST MOLAR READOUT- +5 TO + 8 DEGREE
SECOND MOLAR MAINTAIN 15 DEGREES

THE THIRD AND FINAL STEP OF
PREPARATION IS INITIATED.
 A 5 DEGREE DISTAL TIP PLACED
MESIAL TO SECOND PREMOLAR
BRACKETS.
 COMPENSATING BEND PLACED IN
EMBRASURE BETWEEN SECOND
PREMOLAR AND FIRST MOLAR.
 AGAIN ARCH WIRE IS AT ANGULATION
TO SECOND PREMOLAR BRACKET.

 HEAD

GEAR IS WORN TO VERTICAL
SPURS.
 THE SECOND PREMOLARS NOW
BECOME THE RECIPIENTS OF THE
10-2 SYSTEM.
 AT THE END READOUT MUST SHOW:
 SECOND MOLARS AT 15 DEGREE
 FIRST MOLARS AT 5 TO 8 DEGREE
 SECOND PREMOLARS AT 0 TO 3
DEGREE .

END OBJECTIVES OF TREATMENT OF
CLASS I MALOCCLUSION ARE:
 COMPLETE

SPACE CLOSURE IN BOTH

ARCHES.
 SEQUENTIAL ANCHORAGE
PREPARATION IN MANDIBULAR ARCH.
 ENHANCED CURVE OF OCCLUSION IN
THE MAXILLARY ARCH.
 CLASS I INTERCUSPATION OF
CANINES AND PREMOLARS.



MESIOBUCCAL CUSP OF MAXILLARY
FIRST MOLAR SHOULD FIT INTO
MESIOBUCCAL GROOVE OF
MANDIBULAR FIRST MOLAR.

 THE

DISTAL CUSPS OF THESE TEETH
SHOULD BE DISCLUDED AS THOSE OF
SECOND MOLARS.


CLASS II FORCE SYSTEM
APPLICABLE FOR CASES WITH AN
END-ON OR FULL STEP CLASS II
RELATIONSHIP OF THE BUCCAL
SEGMENTS.
CORRECTIONS WILL BE BASED ON:
 ANB RELATIONSHIP
 MAXILLARY POSTERIOR SPACE
ANALYSIS
 PATIENT COOPERATION.

GUIDELINES FOLLOWED IN TREATING
 IF

ANB <5 DEGREE AND MAXILLARY
THIRD MOLARS MISSING, CLASS II
FORCE SYSTEMS WORK BEST WITH A
COOPERATIVE PATIENT.
 ANB IS 5 TO 8 DEGREES,CLASS II
CUSP RELATIONSHIP,COOPERATIVE
PATIENT. EXTRACTION OF SECOND
MOLARS IS ADVANTAGEOUS.THE
FORCE SYSTEM WILL THEN DISTALIZE
THE MAXILLARY ARCH IN
EXTRACTION SPACE.

 ANB

> 10 DEGREES ,PATIENT
COMPLIANCE IS
QUESTIONABLE,FIRST MOLAR
REMOVAL OR SURGICAL
CORRECTION SHOULD BE
CONSIDERED.
ARCHWIRES
MAXILLARY : .020X.025 WITH CLOSED
BULBOUS LOOPS BENT FLUSH
AGAINST THE SECOND MOLAR
TUBES.
MANDIBULAR: .021X.028 STABILISING
ARCHWIRE WITH LOOP STOP 0.5 MM
SHORT OF MOLAR TUBE.

CLASS II FORCE SYSTEM

AFTER THE FORCE SYSTEM IS
EMPLOYED FOR A MONTH OR SO
 THE BULBOUS LOOPS ARE
ACTIVATED AGAIN TO 1 MM.
 .030 SLIDING JIGS ARE FABRICATED
AND PLACED ON MAXILLARY
ARCHWIRE SUCH THAT DISTAL
EYELET CONTACTS MESIAL BRACKET
OF MAXILLARY FIRST MOLARS AND
THE MESIAL EYELETS ARE MIDWAY
BETWEEN CANINE AND PREMOLAR
BRACKETS.

AFTER FOUR MONTHS OF TREATMENT
WITH MONTHLY REACTIVATION, AN
OVER TREATED CLASS I
RELATIONSHIP IS ACHIEVED.
 REFABRICATE

MAXILLARY ARCH WIRE
WITH 6.5 MM CLOSING LOOPS DISTAL
TO LATERAL INCISORS. CLOSING
LOOPS OPENED 1MM PER VISIT.
 CLASS II FORCES REDUCED TO 4 TO 6
OZ.ANTERIOR ELASTICS AND
HEADGEAR TO BE USED IN
CONJUNCTION WITH ELASTICS.

DENTURE COMPLETION
MAXILLARY AND MANDIBULAR ARCHWIRES
PROGRESSED TO .021X .O28.
 LIGHT CLASS II ELASTICS MAINTAINED
 CRITICAL STUDY OF INDIVIDUAL TOOTH
ARRANGEMENT AS WELL AS INTER ARCH
RELATIONS DONE.
 PROGRESS CEPHALOGRAM AND TRACINGS
DONE TO EVALUATE FINAL MANDIBULAR
INCISOR POSITIONS AND MINOR CONTROL
OF PALATAL,OCCLUSAL AND MANDIBULAR
PLANES.



 TRACINGS

WOULD ALSO REVEAL
REQUREMENT OF LINGUAL ROOT
TORQUE IN MAXILLARY INCISORS.

 FORCE

SYSTEMS ARE REPEATED IF
ORTHODONTIST NOT SATISFIED.

 AFTER

OVER CORRECTION,FINAL
ARTISTIC BENDS AND CUSP SEATING
FORCES GIVEN TO PROVIDE QUALITY
AND DETAIL.

END OBJECTIVES








INCISORS MUST BE ALIGNED.
OCCLUSION OVERTREATED TO CLASS I
RELATIONSHIP.
ANTERIOR TEETH MUST BE EDGE TO EDGE.
MAXILLARY CANINE AND PREMOLARS
MUST LOCK TIGHTLY INTO CLASS I
RELATIONSHIP.
MESIOBUCCAL CUSP OF MAXILLARY FIRST
MOLAR MUST OCCLUDE IN THE
MESIOBUCCAL GROOVE OF MANDIBULAR
FIRST MOLAR.

 DISTAL

CUSPS OF FIRST AND
SECOND MOLARS MUST BE OUT OF
OCCLUSION.

 ALL

SPACES MUST BE CLOSED TIGHT
FROM SECOND PREMOLARS
FORWARD.


DENTURE RECOVERY
ALL TREATMENT MECHANICS ARE
DISCONTINUED TO ENABLE IDEAL
RESULTS.
 ALL BANDS EXCEPT FOR CANINES AND
FIRST MOLARS ARE REMOVED.
 FIRST MOLARS LIGATED TO CANINES IN
UPPER AND LOWERARCHES.
 CANINES LIGATED TO EACH OTHER IN
MANDIBULAR ARCH.
 FOR THE MAXILLARY ARCH ,POWER
CHAINS GIVEN FOR CANINES.





AFTER SEVEN DAYS, REMAINING
BANDS REMOVED AND RETAINERS
PLACED.

 RECOVERY

OCCURS DURING THIS
PERIOD WHEN FUNCTION SETTLES
THE TEETH INTO THEIR MOST
EFFICIENT ,HEALTHY AND STABLE
POSITIONS.


CONCLUSION
‘ NOTHING WORTHWHILE EVER DEPARTS’

IT FIRMLY STOOD THE TEST OF
TIME. MODIFICATIONS WERE MADE
FROM TIME TO TIME.BUT THE
APPLIANCE REMAINED WHILE
OTHERS VANISHED BENEATH THE
SANDS OF TIME.


THANK YOU


REFERENCES
GRABER AND VANARSDALL 2ND AND 3RD
EDITIONS
 CLINICAL ORTHODONTICS – CHARLES
TWEED
 AJO 31: 74-103,1945 PHILOSOPHY OF
ORTHODONTIC TREATMENT ,TWEED
 ANGLE 1936,208 & 256 PART 1 AND 2
PRINCIPLES OF ORTHODONTIC
TREATMENT,TWEED
 AJO 52(11):804-832,1966 THE PROFILE LINE
AS AN AID IN CRITICALLY EVALUATING
FACIAL ESTHETICS, MERRIFIELD



Tweed merrifield /certified fixed orthodontic courses by Indian dental academy

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