EDGEWISE PHILOSPHY,MDS,ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS

EDGEWISE PHILOSPHY,MDS,ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS

1. Presented by:Presented by:
SonalSonal
MDS IIIrd yearMDS IIIrd year
Department of OrthodonticsDepartment of Orthodontics

2. CONTENTS
ANGLE’S VIEW’S
EVOLUTION OF EDGEWISE BRACKET
CONCEPT OF IDEAL ARCH
ARCH WIRE FABRICATION – 1
ST
, 2
ND
, 3
RD
ORDER BENDS
TWEED PHILOSOPHY
TWEED – MERRIFIELD PHILOSOPHY
- Merrifield’s additional contributions
- Four premises of the philosophy
- Differential diagnosis
APPLICATION OF PHILOSOPHY INTO PRACTICE
- Five concepts of the treatment philosophy
- Sequential banding and bonding
- Sequential tooth movements
- Sequential mandibular anchorage preparation
10 – 2 system
Class – II force systems
- Directional force application
- Proper timing of treatment
TWEED-MERRIFIELD SEQUENTIAL EDGEWISE DIRECTIONAL FORCE TREATMENT
CONCLUSION

3. The edgewise arch mechanism was the brain child of this master technician

4. Introduction
•The edgewise arch mechanism/appliance was Dr
Angle’s last and greatest contribution to orthodontics,
after almost a lifetime devoted to improvement of
orthodontic appliances.
•Described it to Fedrick Noyes:
“All you can do is push, pull or turn a tooth. This
appliance is as fine as I can make it. I have given
you the appliance. Now for God’s sake use it.”

5. •Edgewise mech was designed to place teeth into
Angle’s concept of line of occlusion:
“the line with which in form and position according to
type, the teeth must be in harmony if in normal
occlusion.”
•Angle believed that there could be only one true
line of occlusion and it must be the same as the
architectural line on which the denture apparatus
was constructed.
•This ideal line was intended not only to govern the
length and breadth of the dental arches, but also
the size and pattern of each tooth cusp and inclined
plane composing these arches.

6. At last there was an appliance with which all
necessary tooth movements, such as
- restoration of normal arch form,
- correction of all rotations and
- all en mass movements of teeth necessary for
normal cuspal relationships could be achieved.
No concern was raised to the resultant bimaxillary
protrusion that was the usual aftermath of such
treatment procedures.

7. Angle’s philosophy of treatment
The prevalent assumption was that, if cuspal
interdigitation of teeth were made normal,
stimulation by function would result in growth of
basal bone structures.
Little or no thought was given to the inclination of
the mandibular incisor teeth or to normal mesiodistal
relation of teeth and their respective jaw bases and
head structures.
It was assumed, function would take care of such
matters.
Extraction of teeth for orthodontic therapy wasn’t
even an option .

8. HISTORY : EVOLUTION OF EDGEWISE

APPLIANCE

9. E.H. Angle – Graduation 1878, experienced many
technical problems and frustrations in treatment which
irritated, motivated and inspired him to develop a
standard appliance.
His obsession for order motivated him to create the
Angle System 1887 : this ultimately resulted in the multi
banded edgewise appliance 5yrs before his death.
5 ideal properties of an orthodontic appliance according
to Dr . Angle are :
▫SIMPLE : must push ,pull and rotate teeth
▫STABLE : must be fixed on the teeth
▫EFFICIENT : must be based on NEWTON’S 3
RD
LAW
and anchorage
▫DELICATE : must be accepted by the tissues and must
not cause inflammation and soreness
▫INCONSPICUOUS : esthetically acceptable

10. Attempt to incorporate these ideal properties into
an appliance by Angle led to development of
series of brackets of which ended with Edgewise
bracket which is Angles last and best contribution
to Orthodontics.

11. EVOLUTION OF EDGEWISE BRACKETS:
ANGLE E-ARCH
PIN & TUBE
RIBBON ARCH APPLICANCE
EDGEWISE APPLIANCE.

12. E-arch
In the late 1800s the orthodontic appliance was
some sort of rigid framework to which the teeth
were tied so that they could be expanded to the
arch form dictated by the appliance.

13. E-arch was an improvement on this basic design.
It employed crown movement of teeth with simple
anchorage.
Brass wire ligature and stationary anchorage in the
molar area were used to expand all the teeth into
normal occlusion.
Bands were placed on molar teeth and heavy
labial arch wire extended around the arch. The end
of the wire was threaded and a small nut placed
on the threaded portion of the arch allowed the
archwire to be advanced so that the arch perimeter
increased.
Individual teeth were simply ligated to this E-arch.

14. E-arch appliance

15. The heavy archwire was supplied in 4 designs:
1.Basic E-arch used with baker’s anchorage
2.Ribbed E-arch used in expansion by tying brass
ligatures to arch wire
3.E-arch without threaded ends that fit into the molar
sheaths, used with attachment for high pull
headgear.
4.E-arch with hooks in maxillary wire,used to move
entire maxillary dentition distally.

16. Basic E-arch used with baker’s
anchorage

17. Ribbed E-arch used in expansion by tying
brass ligatures to arch wire

18. E-arch without threaded ends that fit into
the molar sheaths, used with attachment
for high pull headgear.

19. Advantage:
- Simplicity
Disadvantge:
- Can deliver only heavy intermittent forces
- Capable of only tipping teeth to new position, no
precise tooth positioning possible.
- Correction of axial inclination of teeth cant be
accomplished.
Angle concluded that it was not possible to get
bodily tooth movement.

20. Pin and tube appliance
To overcome the inability of E-arch to perform
precise tooth positioning, Angle placed bands on
other teeth and used vertical tubes on each tooth
into which soldered pins from a smaller arch wire
was placed .
With this appliance tooth movement was
accomplished by repositioning the individual pins
at each appointment.

21. Pin and tube appliance
Orthodontist had to expertly
solder pins, fit pins perfectly
into tubes on the bands,
remove the pins, move the
pins along the archwire,
solder pins again and fit
pins once again into tubes on
bands..to bring about tooth
movement.

22. •Disadvantage: This appliance demanded such
high degree of skill to obtain the parallelism
between pin and the tube on the archwire that
very few could master this technique.
•Soldering and unsoldering of the pins precisely
was required at each appointment which was
time consuming and tedious.
•The rotational control was difficult

23. Ribbon arch appliance (1915)
Angle modified the tube on each tooth to provide
a vertically positioned rectangular slot behind the
tube…i.e,brackets with vertical slot.
Thus brackets were introduced with this new
appliance.
Gold ribbon arch wire was placed into the slot and
held with brass pins.
Had good spring qualities and efficient in aligning
malposed teeth.

24. Ribbon arch appliance

25. This was first appliance in which actual bracket
was used and it had vertical slot .This appliance
used tipping movement of the teeth, where teeth
moved like beads strings along the archwire.
The main advantage of this appliance was that
rotational corrections could be easily
accomplished.

26. Disadvantage:
not suitable for enmass tooth movement.
Mesial and distal tipping bends could not be
incorporated into the archwire.
Poor root positioning control
Resiliency of the arch wire did not allow
generation of the moments necessary to torque
roots to a new position.

27. Edgewise appliance
(introduced 1928)
•To overcome the difficulties of the previous
appliances Angle changed the form of the
bracket by locating the slot in the centre and by
placing it in the horizontal plane instead of the
vertical plane. The archwire was held in the slot
by ligature wire.
•This bracket was called EDGEWISE BRACKET,the
slot size was 0.022 x 0.028 which opened
horizontally.
•This new design provided better control and
efficient torquing mechanism.  

28. Edgewise bracket when
formed consisted of 3
walls within the bracket.
0.022 x0.028..
Slot oriented
horizontally.

29. –Unique feature  rectangular wire in
rectangular slot  twisting / torquing forces
could be imparted to control the axial
inclination of teeth
–So its possible to move teeth in all 3 planes of
space with a single arch wire.

30. Evolution of edgewise bracket
• 1) Single width EW bracket with
eyelet: The original edgewise bracket
was 0f 0.050 wide and soldered to the
gold band material .
•B’coz of the narrow width , it was
inefficient in rotational control.
•To overcome this problem Angle designed
a soldered golden eyelet to be placed in
apppropriate position on the band ,
ligature wire was tied from the eyelet to
the archwire for rotational correction.
•This was time consuming and inefficient.

31. 2) TWIN BRACKET: (siamese twin
brackets)
 Swain..originator of the idea (1952).
 Two edgewise brackets joined together on
common base.
 0.05 inch distance b/t the two.
 4 types:
 Extra wide, standard, intermediate and junior.

32. Advantage of twin bracket:
1. Effective for rotation correction.
2. Greater axial control
3. Incorporates positive control: once tooth
has been derotated, mere tying of wire
to bracket with ligature maintains the
tooth in its corrected position.

33. Disadvantage:
 Because of the increased width of the twin bracket, the
amount of wire available b/w brackets on the arch
decreased.
 Adverse effect on inherent resiliency of archwire.
Also if the wire is to slide posteriorly during activation of
closing loops, the decreased inter bracket span interferes
with the amount of closing action that can be obtained.
The narrower backets allows more activation of these
wires.

34. Curved base twin bracket
To adapt properly to the curved surface of canine and
premolar teeth.
Disadvantage: Disadvantage of the twinbrackets is
decrease interbracket span which in turn reduced the
interbracket span of the archwire and hence the archwire
flexibility.(Creekmore).

35. Developed by Lewis in 1950
Another approach to address problem of rotation correction
It consists of auxillary rotational arm that abutts against the
bracket itself and thus offered a lever arm to deflect the
archwire and bring about the rotational correction.
One piece bracket with integral rotation wings
These wings do not interfere with occlusogingival deflections
of archwire & do not decrease the interbracket span
 
3) Lewis bracket:

36. Vertical slot Lewis bracket:
These brackets have vertical slot of size 0.020X0.020 ,so
that uprighting springs could be used if needed.
 

37. 4) Steiner brackets:
Given by Cecil C Steiner in 1931
Flexible rotation arms incorporated…so did not
depend entirely on resiliency of archwire for tooth
rotation.
Introduced tie wings for ease.
Once the permanent deflection of arms has
occurred, complete rotation will not be effected
unless the arms are readjusted to their original
position of ligation

38. 5) Broussard bracket:
Designed by Garford Broussard
Addition of 0.0185 x0.046 vertical slot to accept
a doubled 0.018 auxillary wire.

39. Evolution of edgewise buccal tube
•Original appliance had .022x .028 inch
gold or nickel silver tubing soldered to
the molar band
•Length –3/16 or ¼ inch
•Notched distal ends- to facilitate a tie
back ligature
•Hook –gingival to buccal tubes ,soldered
on the bands for placement of elastics
•Inconel tube- Gold buccal tubes were
discarded
•Stamped buccal tube with welding
flanges or
•inconel tube which could be soldered to
the band

40. Combination buccal tubes
Incorporates a round tube
for insertion of a face bow
Fairly close tolerances must
be maintained between
archwire & tube for
effective transmission of
torque to the tooth
Triple buccal tube
 Additional rectangular
tube for auxillary sectional
& base archwire

41. Bracket & tube placement
Angle“goal of correct bracket & tube placement is to
produce an ideal occlusion at the end of treatment with flat
,straight ,ideal archwires
Tweed advocates – millimeter measurement from bracket slot
to the incisal edge
UPPER ARCH LOWER ARCH
Centrals –4.5 Anteriors-4.0
Laterals –4.0 Canines-4.5
Canines –5.0 Premolars-5.0
Premolars-4.5 Molars-4.0
Molars –3.5

42. Bracket angulation
According to Angle: Brackets positioned parallel
to the long axis of the tooth
He also suggested angulating posterior bracket to
produce desired tooth movements.
On 1941 Tweed, pointed out the short comings of
this approach. He advocated arch wire bends to
obtain correct axial inclinations and called them
“artistic positioning” bends.

43. Holdaway (1952) described three uses for bracket
angulation
a) as an aid in paralleling roots adjacent to
extraction spaces
b) as a method of setting up posterior anchorage
units into tipped back or anchorage prepared
positions
c) as a means of obtaining correct axial inclinations
or artistic positioning

44. Ideal Arch Form
For maximum stability the
teeth should be
positioned as dictated
by Angle’s “Line of
occlusion”.
“ the line with which, in form
and position, according
to type, the teeth must
be in harmony, if in
normal occlusion”

45. Ideal Arch Form
Maxillary anterior arch form

46. Ideal Arch Form
Mandibular anterior arch form

47. Ideal Arch Form
Maxillary premolar and
molar region

48. First Order Bends
To contour the arch wire to the buccal surfaces of
teeth, which vary in their labio-lingual thickness and
do not conform to an arch.
The extent of each bends is dictated by the labio-
lingual thickness of individual teeth so that a smooth
curve of incisors and canines on their lingual surface
can be achieved.
These are:
–Lateral inset
–Canine eminence
–Molar offset/anti-rotational bend/toe-in bend

49. Ideal Arch Form

50. Fabrication

51. Second Order Bends
Bends in the occluso-gingival direction to maintain the final
angulation of teeth.
In the incisal area, second order bends (artistic bends)
provide the ideal root angulation to these teeth in
mesiodistal direction.
In posterior region, second order bends maintain the distal
tipping of the pre-molars and molars and cause bite
opening (pseudo bite opening).

53. Fabrication
• To differentiate between anterior and posterior
segment.
• To give separate anterior and posterior root torque.
• For soldering attachments.
• The heights of the mesial and distal arms of the V
bend determine its action in occluso-gingival plane as:
•Neutral (when mesial and distal arm of the V bend
are of same height) and bearing zero force and
moments.
•Step up when mesial arm is shorter in height (to
maintain or open the bite)
•Step down when mesial arm is greater in height (to
close open bite).

54. Fabrication

55. Tip back bends are placed to reinforce anchorage.
In the maxillary arch it should be coupled with class II elastics
If second order bends are placed in the maxillary arch
without Class-II elastics, the uncontrolled forces move the root
apices of the teeth in the buccal segment in mesial direction
without distal movement of the crown.
In such instances it will lead to mesial displacement of the
teeth in the buccal quadrants of both arches resulting
bimaxillary protrusion.

56. Third order bends
Torsional bends along the long axis of the
rectangular arch wire are called third order
bends or torque.
Torque may be:-
* Buccal or lingual
* Passive or active torque.
* Continuous or progressive torque.

60. Continuous torque is recommended in the
mandibular incisor region where as progressive
torque is recommended in the posterior region.
In pre-adjusted edgewise appliance system,
torque values are built-in in the brackets.
However, a variation of torque in a segment or
for an individual tooth may required for proper
finishing the case .

61. TWEED’S
PHILOSOPHY

62. Dr.Charles.H.Tweed

63. CHARLES H.TWEED : Graduated from an improved
Angle course in 1928 at the age of 33yr.
Helped Dr.Angle in publishing an article in the dental
Cosmos.
Returned to Arizona and in Pheonix established the
First pure edgewise speciality practice in U.S.
For the next 2yr with Dr.Angle’s advise followed
edgewise technique .

64. Dr.Angle urged his dear student to :
1.Dedicate his life to the development of the
edgewise appliance
2.To make every effort to make orthodontics as an
speciality within the dental profession.
Following advise Dr.Tweed instigated the first
orthodontic specialty law in the U.S..
In 1929 first law limiting the practice of orthodontics
to specialists was passed ;
Dr.Tweed received certificate No.1. in Arizona to
become the first certified specialist in orthodontics in
the U.S.

65. Aug 11, 1930, Angle died at age of 75yr.
Tweed held to Angle’s conviction that one must
never extract teeth, but this lasted for only 4yrs.
In 1932 published article in Angle orthodontist
“reports of cases treated with Edgewise Arch
mechanism.”
What he observed in his patients during retention
was so discouraging for him that he almost gave up
practice. He devoted the next 4yr studying his
successes and failures.
He made a most important observation:

66. Lack of harmony in facial contour was in direct
proportion to the extent to which the denture
had been displaced mesially into protrusion.
Upright mandibular incisors frequently were
related to post treatment facial balance and
succesful treatment.

To position mandibular incisors upright ,he
concluded one must prepare anchorage and
extract teeth.

67. He selected failed cases and treated them with
premolar extractions.
Was called a traitor ,faced critisism.
In 1940 he produced case reports of the
retreated cases.

68. Tweed made considerable effort to place
mandibular incisors at 90 +/- 5 deg to MP
without resorting to removal of teeth. In some
cases this was achieved by over expansion of
dental arches , but too often at the expense of
impacting both unerupted 2
nd
and 3
rd
molars.
The aftermath of such treatment was relapse and
damage to investing tissue.

69. Tweed’s philosophy can be discuss
under the following headings:

70. Tweed classified growth trends
into three types
1.Type A growth trends :
 Middle and lower face are growing forward and
downward in unison with no change in the ANB angle.
 Growth is aprroximately equal in both vertical and
horizontal dimensions.
 The facial changes are from very good to dramatic. The
mandibular incisors remain free from crowding and stable
b’coz both the mid and lower face are growing in unison in
downward and forward direction with no conflict between
U/L incisors.
•Incidence - 25% of the population have this type of
growth.

72.  If molar relationship is class II and the ANB exceeds
4.5deg its Type A subdiv growth trend.
 It is better to place the patient on Kloehn cervical
Headgear to restrain maxillary growth.
 Prognosis is good because the point B is moving
forwards as the maxillary denture is moved
posteriorly.

73. •Type B growth trend :
 The middle face is growing forward more rapidly
than the lower, ANB increases in size with growth.
 If ANB is ranging from 6-12 deg
 - prognosis is fair,
 - good facial changes and
 - good occlusion.
 They have to be treated at an early age
 Point B will drop down and back with treatment
and attainment of FMIA of 65o is impossible.
 Treatment will be of prolonged duration
extending upto 36 –42 months.

75. Type C growth trend:
The lower face is growing forward and downward
more rapidly than the middle face, with a decrease
in the size of the ANB.
Prognosis is very good from the point of view of
facial esthetics.
But during retention one has to observe for any
lingual tipping of mandibular incisors (orbicularis oris
is strong) or labial tipping of maxillary incisors
(orbicularis oris is weak).
 Prolonged retention may be required depending
on the type of perioral musculature
Incidence – 60% of the population

77. Anchorage preparation:
Stable anchorage –important to prevent forward movement of
mandibular denture when Class II intermaxillary force is
applied
On histological basis Brodie (1937) believes that the
strongest anchorage is provided by stable fixation of teeth
–to allow as little movement as possible
Tweed – anchor teeth best resist the dislodging forces when
their vertical axes are parallel to the direction which offers
the most advantageous mechanical resistance against the
pull of dislodging forces
 

78. •Strongest anchorage is provided by tipping back the crowns
of the teeth so that they will have a disto-axial inclination
that will resist a forward pull
•First & most important step in treatment - Anchorage
preparation
•If anchorage preparation is not done -the action of
intermaxillary elastics cause elevation of terminal molars &
depression of mandibular incisors.
•Thus,
•canting of occlusal plane,
•increase in FMA ,
•point B drops downward & backward ,
•entire mandibular denture is tipped & displaced forward
into protrusion

79. There are three degrees of anchorage
preparation.
1
st
degree anchorage preparation.
  It is done in cases with
> ANB – 0-4
0
> Good facial esthetics
> Total discrepancy –
10mm
 

80. Mandibular terminal molar must be always upright or
maintained in such upright position to prevent them
from being elongated with class II intermaxillary force.
As a general rule the inclination of the lower terminal
molar should be such that the direction of the pull of
the intermaxillary elastics should not exceed 90
degree when related to the long axis of the terminal
molar.
 
Exp: Highly placed canines
True class III malocclusion.
 

81. IInd degree anchorage preparation:
Indications
  > ANB – 4.5
0
> Facial esthetics make it desirable to move
point B anteriorly and point A posteriorly.
> Requires prolonged class II intermaxillary
mech
The terminal molar should be distally tipped so that
their distal marginal ridges are at the gum level.

83. IIIrd degree anchorage preparation:-
 It is also called Total anchorage preparation.
Indications
> ANB - >5
0

> Severe malocclusion with space
discrepancy of14-20mm

Exp:- Class I malocclusion with severe crowding
Bimaxillary protrusion
 Distal tipping of the terminal molar is such that the
distal marginal ridge is below the gum level.
 

85. TWEEDS CONTRIBUTIONS:
a)Emphasized 4 objectives of orthodontic
treatment with emphasis & concern for facial
esthetics.
1.The best balance and harmony of facial lines
2.Stability of dentures after treatment
3.Healthy mouth tissues
4.An efficient chewing mechanism
b)Developed the concept of uprighting teeth over
basal bone with emphasis on the mandibular
incisors
c)Made the extraction of teeth for orthodontic
correction acceptable & popularized extraction
of 1
st
pre molar.
d) Enhanced the clinical application of
cephalometrics.

86. e.Developed diagnostic facial triangle to make cephalometrics a
diagnostic tool as well as a guide in treatment & evaluation of
treatment results.
1. The normal range of inclination of the mandibular
incisors to MP was 90+/- 5deg. (IMPA)
2. when he was working on why he could not make his
unfavorable patients beautiful like his favorables even with
identical treatment, he found out that the FMA was the
difference (recognised the importance of different growth
trends)
norm=25 deg, range=16-35deg;
extraction of teeth was more necessary in patients with FMA
>30deg.
3. 3
rd
angle FMIA was 65 deg. The size of the FMIA was found
crucial in creating satisfactory facial esthetics with orthodontic
treatment.

87. Tweed’s diagnostic facial
triangle

88. f. Developed concepts of orderly treatment
procedures & introduced anchorage preparation
as a major step in treatment
g. Developed a fundamentally sound pre orthodontic
guidance program using & popularizing serial
extraction of primary & permanent teeth.

89. Angle gave orthodontics the Edgewise bracket, Angle gave orthodontics the Edgewise bracket,
but Tweed gave the speciality the appliance.but Tweed gave the speciality the appliance.
Tweed was considered the premier edgewise
orthodontist of his day, many who admired his
results took the course and learnt his method of
treatment.
The TWEED PHILOSOPHY was born.
He devoted 42yrs of his life from 1928 till his
death on Jan 11, 1970 to the advancement of
edgewise appliance.

90. Levern Merrifield
LEVERN MERRIFIELD
1953 : took TWEED course
1960 : selected by
Dr.Tweed to be codirector
and continue his work on
edgewise appliance.
1970 : Director  study of
orthodontic dentistry &
development of
edgewise appliance

91. Merrifield’s contributionsMerrifield’s contributions

92. Introduced diagnostic analyses which allow clinicians
to determine whether and when extractions are
necessary, if indicated which teeth to be extracted.
A.Diagnostic concepts:
1) The fundamental concept of the dimensions of the
dentition.
2) Dimensions of the face.
3) Total space analysis
4) Guidelines for space management decisions to achieve
the following.
–Facilitate maximal orthodontic correction
–Define the areas of skeletal, facial and dental
disharmony.

93. B) Treatment Concepts
1)Directional control during treatment
2) Sequential tooth movement
3)Sequential Mandibular anchorage preparation
4) The Organization of treatment into 4 orderly
steps that have specific objectives.
 

94. Merrifield’s philosophy
and diagnosis

95. The Tweed-Merrifield
philosophy
Position and arrange the teeth for maximum facial facial
balance and harmonybalance and harmony,
Position and arrange the teeth for maximum health maximum health of
the teeth, the jaws, the joints and the surrounding tissues,
Position and arrange the teeth for maximum functional for maximum functional
efficiencyefficiency,
Position and arrange the teeth for maximum stability stability
and estheticsand esthetics,
Position and arrange the teeth on the immature patient immature patient
to harmonize the correction with normal growth to harmonize the correction with normal growth
processes and maximize the compensation for the less processes and maximize the compensation for the less
than normal patternthan normal pattern, and

96. Position the denture and arrange the teeth so that both are in a
continual state of maximum environmental harmonyenvironmental harmony. (This
objective can be realized only if the first five objectives have
been successfully achieved.)
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 public public
welfarewelfare.
The all important seventh objective is the crux of the philosophy.

97. 1)Recognise the dimensions of the dentition and
treat for maximum facial harmony and balance
This means non-expansion of malocclusion when
the normal muscular balance exists.
2) Recognize the dimensions of lower face and
treat for the maximal facial harmony and
balance.
3) Recognize and understand the skeletal
pattern.

98. The dimensions of the dentition (4 basic premise)
Premise 1: Anterior limits
The teeth must not be placed forward,
off basal bone.
If placed forward, objective of the
treatment are compromised.
Premise 2: Posterior limits
Teeth can be positioned and /or
impacted into the area behind the mandibular
1
st
molar even as they can be moved too far
forward off basal bone.

99. Premise 3: Lateral limits
If teeth are moved buccaly into masseter
and buccinator muscles, relapse is likely to result.
Premise 4: Vertical limits
Vertical expansion is disastrous to facial
balance & harmony in the sagital plane, except in
deep bite cases.
Anterior limit, posterior limit, lateral limit and vertical
limit exists..these limitations must be recognised and
treatment designed to conform to these limitations
when normal muscle balance exists.

100. Diagnosis of Orthodontic and Orthognathic
disharmony should be based on four major areas: –

> Facial
> skeletal
> Environmental
> Dental.
 
 

101. Facial Disharmony
  Factors affecting the facial balance
  1. Position of the teeth
2. Skeletal pattern.
3. Soft tissue thickness : total chin thickness and upper lip
thickness must be equal
 
Facial balance is affected by
1) Protrusion of teeth
  2) Retrusion of teeth
  3) Crowding of teeth
 
 

102. “Facial disharmony can result from abnormal skeletal
relationship. The clinician must understand the
skeletal pattern and have the ability to compensate
for the abnormal skeletal relationship by changing
the position of the teeth.”
Careful consideration of these factors will enable the
clinician to determine whether dental compensation
will improve facial balance.

103. Upper lip thickness and total chin thickness
If the total chin
thickness is lesser than
upper lip thickness, the
anterior teeth must be
positioned upright
further to facilitate a
more balanced facial
profile because lip retraction
follows tooth retraction

104. Some measurements to judge facial balance:
1.Profile line
2. On frontal view vermilion border of the lower lip
should bisect the distance between the bottom of
the chin and the ala of the nose.
3.FMIA : Tweed believed this angle was significant
in establishing balance and harmony of the lower
face. Related to FMA.
For FMA 22-28 deg, FMIA 68deg
Standard : FMA 30 deg ; FMIA 65deg.
dental compensation for a high FMA requires
additional uprighting of flared mandibular
incisors..visa versa.

105. 4.Z – angle :It is the angle between the FHP and line
joining the soft tissue pogonion to the most anterior
lip
Its indicative of soft tissue profile and more
responsive to maxillary incisor retraction than FMIA
70-80 deg normal range
75-78 deg ideal, depending on age and gender.
The Z angle quantifies the combined abnormality
in the values of FMA,FMIA and soft tissue chin
thickness.

106. Profile line in a balanced face
When facial balance is
present, the ideal
relationship of profile
line is to be tangent to
the chin and the
vermillion border of
both the lips and should
lie in the anterior 1/3
rd

of the nose.

107. Profile line not in balance

108. Skeletal dishamony
To strive for a harmonious relationship of maxilla
and mandible to each other and to the cranial
base is an important responsibility of an
orthodontist.
 Disproportion of these bones or mal-relationship
with other bones in the cranium can be favorably
influenced by dental repositioning during the
growth period.

109. The following cephalometric readings can be used in assessing the skeletal
relationship:
 
FMA, IMPA
 SNA, SNB,ANB
AO-BO
Occlusal plane
Facial height index 65% - 75%
Merrifield and Gebeck reported a 2:1 increase in
PFH compared to AFH in successfully treated
Class II patients.

110. Environmental Disharmony:
 The most challenging area of the Orthodontic
treatment is to correct the Environmental
abnormality.
Bones
Muscles
Blood supply Make up the Environment.
Nerve supply
Soft tissue

111. ENVIRONMENT
 Functional Element Static Elements
1) Joints 1.Bone
2)Muscles 2.Cartilage
–Facial expression 3.Soft tissue
– Mastication.
3) Deglutition
4) Speech
5) Respiration.

112. It is important to recognize the deformities and
disharmonies in the environment and every effort be
made to harmonize all the elements of the
environment.
 Final results of the treatment cannot be stable
unless Environmental harmony is achieved, no matter
how good the mechanotherapy has been.
 Ex:- Habit correction.
Treatment of joint disorders.
 

113. Dental Disharmony:
Orthodontic treatment is a space management
procedure.
 It is crucial to identify the areas of dentition space
deficit or space surplus.
 
The entire arch divided into three areas:
- Anterior arch area (from canine to canine)
- Mid arch area (first and second premolars and
first molar)
- Posterior arch area.(area distal to first molar)
 

114. Treatment with
Tweed-Merrifield Edgewise
appliance

115. The appliance
As angle stressed the appliance must have
-Simplicity
-efficiency
-comfort
-hygeinic
-esthetic
-versatality.

116. Archwires:
0.017 x0.022
0.018 x0.025
0.019 x0.025
0.020 x 0.025
0.0215 x0.028 inches
Different wire dimensions allow greater versatality and allow
sequential application of forces at diff stages.
Objective is to enhance tooth movement and control with
proper edgewise wire.

117. Auxiliaries used:
Elastics
Directionally oriented headgear:
high pull J-hook headgear
straight pull J- hook headgear
Patient compliance imperative

118. TWEED MERRIFIELD
PHILOSOPHY
Essentialy 5 concepts compose the philosophy:
1) Sequential appliance placement
2) Sequential/individual tooth movement
3) Sequential mandibular anchorage preparation
4) Directional force including control of vertical
dimension which will enhance mandibular response
5) Proper timing of treatment

119. 1)Sequential appliance placement :
1
st
premolar extraction case:
2
nd
molars, 2
nd
premolars banded,
centrals, laterals & canines bonded ;
1
st
molars left unbanded
Maligned anteriors are not ligated to the
archwire,they are ligated passively.

120. TWEED MERRIFIELD EDGEWISE APPLIANCE

121. Advantage :
> Easier
> Less traumatic
> Less time consuming
> Allows greater efficiency in arch wire action
(longer inter bracket span in posterior seg)
This length creates the power storage that
accomplishes 2
nd
molar movement more rapidly.

> Larger dimension wire can be applied, that is
less subject to distorsion.

122. Once banded teeth respond to the force of arch
wire, additional teeth banded
Sequence :
After 1
st
appointment  maxillary 1
st
molars
banded
After 2
nd
appointment  mandibular 1
st
molars
banded
At 3
rd
/4
th
appointment lateral incisors bonded

123. Initial archwires placed
1
st
molars not banded

124. 2) Sequential tooth movement:
-Tweed had advocated enmass tooth movement.
-Tweed- merrifield Sequential tooth
movement
Advantage : Rapid and precise tooth movement
because they are moved individually in small units.

125. Sequential tooth movement

126. 3) Sequential mandibular anchorage preparation:
Tweed : Enmass anchor preparation;
all compensation bends placed at one time in the
archwire and class III elastics used for support
result :
Labially flared and
intruded mandibular incisors
MERRIFIELD developed “10 – 2” system.

127. Merrifield technique –
`10 – 2’ Force systems(10 ten teeth used as
anchor units to tip 2 teeth)
+
High pull head gear for support rather than
class-III elastics
Unlike Tweed’s en mass anchorage tech, in this tech
tooth movement is controlled, sequential and
precise….
Mandibular anchorage can be prepared quickly and
easily by tipping only two teeth at a time to their
anchor prepared position.

128. Initial step of SMAP : 2nd molar is tipped to its
desired anchorage prepared position.
Compensating bend placed mesial to the 2nd
molar to maintain its tip
Ist molar is tipped to anchor prepared position.
Compensating bend placed mesial to molar to
maintian tip
IInd premolar tipped distally to APP.

129. 10 -2 force system
10-2-6
First molar tipped to
Anchor prepared
position

130. 4) Directional force : Hallmark of modern Tweed-
Merrifield edgewise treatment is use of
directional force to move teeth.
Defined as “Controlled forces which place teeth
in the most harmonious relationship with their
environment "

131. Upward and forward force
system
Its critical to employ force
system that controls the
mandibular posterior teeth and
maxillary anterior teeth.

•Resultant force vector of all
forces should be upward and
forward, giving opportunity for
favourable skeletal change,
especially in dento alveolar
protrusion class II
malocclusion correction

132. Upright mandibular incisors allows maxillary incisors
moves up and back
Upward and forward
force system requires
mandibular incisors
upright over basal bone
so that the maxillary
incisors can be moved
distally and superiorly

133. For the upward and forward force system to be a
reality, Control of vertical dimension is crucial; to
control vertical dimension we should control the
> Mandibular plane,
> palatal plane and
> occlusal plane.

134. Downward and backward force
system
If point B is allowed to move
down, mandibular incisors
are tipped off the basal
bone and maxillary incisor
drops down and back
instead of being moved up
and back.

135. This leads to a patient with

 > lengthened face,
 > gummy smile,
 > incompetent lips and
 > more recessive chin.

136. 5. Timing of treatment:
Treatment should be initiated at the time when
treatment objectives can be most readily
accomplished.
> I,e. interceptive in the mixed dentition, or
> waiting for second permanent molar eruption
before starting active treatment.

137. STEPS OF TREATMENT
with Tweed – Merrifield
Technique

138. STEPS OF TREATMENT
TWEED MERRIFIELD DIRECTIONAL FORCE
TREATMENT can be organised into four force
systems :
1)Denture preparation
2)Denture correction
3)Denture completion
4)Denture recovery

139. 1.DENTURE PREPARATION
(apporx 6 months)
Prepares the malocclusion for correction
OBJECTIVES:
a)Leveling
b)Individual tooth movement and rotation correction
c)Retraction of both maxillary and mandibular
canines
d)Preparation of terminal molars for stress
resistance

140. Technique –
1 maxillary & 1 mandibular archwire are used to
complete this step
Sequential banding/bonding of teeth
0.018 x 0.025” resilient mandibular arch wire
0.017 x 0.022” resilient maxillary arch wire
- loop stops flush with second molar tubes
-Mandibular 2
nd
molar 15
0
effective distal tip
-Maxillary 2
nd
molar 5
0
effective distal tip

141. The objective of this distal tip is to maintain the
maxillary molar in its distally tipped position and
to begin tipping mandibular second molar to an
anchorage prepared position

142. Offset bend mesial to 2
nd
premolar bracket is
placed to prevent canines from expanding
-3
rd
order bends is passive in both upper and lower
archwires
-High pull J-hook head gear is used to retract
maxillary and mandibular canines
After each month, archwires are removed &
terminal molar tip is increased to maintain an
effective 15
0
tip as tooth tip distaly

- After 1
st
month Maxillary 1
st
molars banded, J hook
head gear continued for canine retraction

143. Denture preparation
Initial archwires
0.017 x 0.022 resilient
maxillary arch wire
0.018 x0.025 resilient
mandibular arch wire
J-hook hook head gear for
canine retraction.

144. Maxillary molars
Banded after 1
st
month
of treatment
Arches getting levelled
off
Canine retraction with J-
hook headgear
continued

145. As canines retract and arches are levelled ,the
lateral incisors are ligated
Power chain force can be used to aid canine
retraction

At each visit-arch wires removed, co-ordinated,
checked for1
st,
2
nd
3
rd
order bends and religated

146. Terminal molar anchorage:
-The mandibular terminal
molar should be tipped to
anchorage prepared
position at the end of
denture preparation.
- Full dentition should be
bracketed and leveled.
-Canines retracted , all
rotations corrected.

147. MERRIFIELD MODIFICATION in
denture prep
Mandibular arch 
Start with 0.016” with incisal curvature, bent-in loop stops flush
with molar tube
20
0
distal tip for 2
nd
molar (Tweed-15
0
)
If progress slow use 0.018” wire
Maxillary arch
Distal tip 10
0
(Tweed-5
0
)
0.018” and 0.020” arch wires inserted about 1 month after
mandibular arch, in contrast to simultaneous placement of
maxillary and mandibular arch wires in classic Tweed technique

148. 2. DENTURE CORRECTION
OBJECTIVES:
1. Retraction and up-righting of lower incisors to their
planned positions
2. Completion of space closure
3. Achievement of posterior and mid arch axial inclinations
that will permit proper functional co-ordination with the
maxillary teeth

149. Denture correction :space closure
Mandibular wire:
0.019 x0.025 with 6.5mm
vertical loop distal to lateral
incisor bracket.
Maxillary archwire:
0.020 x0.025 with 7mm
vertical loop.
Loop stops immediately are
made distal to brackets of first
molars
Loop stop in mandibular arch
wire incorporates a
compensation to maintain
15deg terminal molar tip

150. Closing loop application:
maxillary and mandibular
closing loops are used to
close spaces mesial to the
distalized canines
Vertical support in maxillary
arch is through J hook HG
(hook b/t central and
lateral)
Vertical support for
mandibular anterior teeth
through anterior vertical
elastics

151. Denture correction: space closure complete
After space closure is
complete:-

> mandibular arch is
level
> curve of occlusion in
maxillary arch maitained
> the terminal molars
remain tipped to an
anchorage prepared
position.

152. This step positions teeth in mandibular midarch &
posterior areas into axial inclinations that will
allow final coordination with maxillary teeth.

153. SEQUENTIAL MANDIBULAR ANCHORAGE
PREPARATION
Is based on sequential tooth movement concept –

Arch wire exerts active force on only 2 teeth,
while other teeth in the arch remaining passive.
Thus, remaining teeth act as anchor units as 2 teeth
are tipped.(“10-2” anchorage system)

154. 1
st
step of SMAP
SMAP is initiated
during Denture prep
step by tipping 2
nd

molar to 15
0
distal
inclination

155. 10-2…first molar
tipped to its anchorage
prepared position
0.019 x0.025 archwire with
loop stops flush agianst 2
nd

molar tubes fabricated.

156. 1
st
and 3
rd
order ideal bends
are incorporated
Gingival hooks for high pull J
hook HG soldered distal to
central incisor bracket.
To tip 1
st
molar into APP,10deg
distal tip placed 1mm mesial to
1
st
molar brackets.
Compensating bend to maintian
15deg 2
nd
molar tip are placed
just mesial to loop stop.

157. The second molars are now part of anchor unit
/stabilizing unit and the first molars are the two
teeth which receive the action of directional forces
and archwire (10-2).
After 1 month arch wire removed, readout should
show 5-8
0
distal inclination of 1
st
molars, 2
nd
molars
should continue 15
0
read out

158. Third and final step of
SMAP –

5
0
distal tip 1mm mesial
to 2
nd
premolar bracket,
compensating bend
between 2
nd
premolar and
1
st
molar to maintain 1
st

molar in APP

159. At end of SMAP, read-out should show :
2
nd
molar = 15
0
distal axial inclination
1
st
molar = 5-8
0

2
nd
premolar = 0-3
0

160. The objectives of denture correction step are
1)Complete space closure in both arches
2)Sequential anchorage preparation in mandibular
arch
3)Enhanced curve of occlusion in maxillary arch
4)Class l intercuspation of canines & premolars.
5)Mesiobuccal cusp of maxi 1
st
molar should fit into
mesiobuccal grove of mandibular 1
st
molar. The
distal cusp should be disocluded, as those of 2
nd

molars

161. CLASS II FORCE SYSTEMS
A different system of forces may be used in
patients with end-on or full cusp class II dental
relationship.
A final diagnostic decision for correction of class ll
is based on –
1) the ANB relationship
2) maxillary posterior space analysis and
3) patient co-operation…using the following
guidelines:

162. 1.If the maxillary 3
rd
molar is missing or if ANB<=
5deg and patient is cooperative… prognosis best
If 3
rd
molar erupting, then its best to remove it to
facilitate distal movement of maxillary teeth.
2. If patient is cooperative, has a mild class II dental
rel, normal vertical skeletal pattern (FMA 28 or
less), ANB 5-8deg and normally erupting 3
rd

molars…then advantageous to extract 2
nd
molars.
3. If ANB >10deg, poor patient cooperation, 3
rd

molars present…after maxillary and mandibular
first premolar extraction space closure, either first
molar extraction or surgical correction considered.
( poor prognosis)

163. Correction of class II dental
relationships
After mandibular anchorage preparation,
- Mandibular 0.0215x0.0275 stabilizing archwire
fabricated with ideal first, second and third order
bends.
- Gingival spurs soldered distal to lateral incisor
brackets.
- Wire passive to all brackets.
- Wire seated and ligated.
- Terminal molar tied tightly to loop stop.

164. 2
nd
molar distalization
Maxillary archwire
0.020x0.025 wire with
closed helical bulbous loops
bent flush against the
second molar tubes.
Ideal 1
st
, 2
nd
and 3d order
bends placed.
Molar segment is given 7
deg progressive lingual
crown torque

165. Gingival spur soldered to
archwire distal to 2
nd

premolar bracket.
Gingival high pull
Headgear hooks soldered
distal to central incisor
brackets.
Class II “lay on’’ hooks with
gingival extention for
anterior vertical elastics
soldered distal to lateral
incisor brackets.

166. 2
nd
molar distalization
Closed helical bulbous loops
are opened 1mm on each
side and arch wire ligated in
place.
Class II elastics of 8 ounces
worn.
Anterior vertical elastics worn
High pull headgear worn.

167. In about a month time the maxillary 2
nd
molar
moves distally.
Helical bulbous loop is reactivated until second
molars have a class I dental relationship; at the
rate of 1 mm per month.

168. maxillary 1
st
molar distalization
Once molar is in class l position,
Coil spring of 1.5 times distance
b/t molar and premolar bracket
is wound mesial to 1
st
molar
bracket.
E –chain is streched from 2
nd

molar to distal bracket of 1
st

molar.
Additionally, Class II elastics,
headgear(14hrs/day), anterior
vertical elastics worn
(12hrs/day).

169. After 1
st
molars as moved
distally into an
overcorrected class I dental
relationship , Spur distal to
2
nd
premolar removed.

170. The coil spring is moved
mesially and
compressed b/w the lay
on hook distal to lateral
incisor and canine
bracket.
Subsequently the 2
nd

premolars and canines
are moved distally with
elastic chains and head
gear force.

171. By four months of active treatment, with monthly
reactivation, posterior teeth should attain an
overcorrected class I relationship.
This will not tax the Mandibular anchorage if
> if sufficient maxillary posterior denture area
available and
> if anterior vertical elastics worn.

172. Maxillary Anterior space closure
0.020x0.025 maxillary arch
wire with 7mm closing loops
distal to lateral incisors.
Ideal 1
st
, 2
nd
and 3
rd
order
bends placed.
Gingival headgear hooks
soldered distal to central
incisors.
Closing loops opened 1mm per
visit by cinching the loop stops
to the molar tube.
Milder 4-6 ounce class II
elastics used instead of 6-8
ounces. Anterior vertical elastics
and maxillary head gear worn.

173. After all maxillary space is
closed…denture correction
completed …denture
ready for next step
DENTURE COMPLETION.

174. Denture completion
Considered as Mini treatment of malocclusion:
The orthodontist uses the force systems that are
necessary, until the original malocclusion is
overcorrected.
Ideal 1st,2
nd
,3
rd
order bends placed in 0.0215x
0.028” resilient maxillary & mandibular finishing
arch wires.
Mandibular archwire duplicates the previously used
mandi stabilising arch wire.
Maxillary archwire has artisitc bends, hooks for
headgear, antr vertical elastics and Class ll elastics.

175. Cephalogram are traced to determine final
mandibular incisor position and any minor control
of palatal, occlusal and mandibular planes that
may be needed.
Visual examination done for evaluation of lip line,
maxillary incisor relationship ,cusp seating, artistic
positioning, need for lingual root torque of upper
incisor .

176. Maxillary and mandibular
stabilizing archwires,
along with proper
elastics and headgear
force used to complete
orthodontic treatment.

177. At end of denture
completion following
characteristics should be
readily observed:
Incisors must be aligned.
Occlusion overcorrected to
class I rel.
Anterior teeth edge-edge
rel, minimal incisal guidance.
Maxillary canines and 2
nd

premolars locked tightly into
class I rel.

178. Mesiobuccal groove of maxillary 1
st
molar must
occlude in mesiobucal groove of mandibular first
molar.
Distal cusp of first molar and second molars must
be slightly out of occlusion.
All spaces must be closed tightly from 2
nd

premolars forward.

180. Denture recovery
The ideal occlusion will occur after all treatment
mechanics are discontinued and uninhibited
function and other environmental influences active
in post-treatment period stabilize and finalize the
position of final dentition.
When all appliances are removed & retainers
placed, a most crucial phase ‘recovery’ phase
occurs
In this stage, forces involved are those of
surrounding environment, primarily muscles and
periodontium.

181. concept of over correction:
If mechanical corrective procedures barely achieve
normal relationships of teeth , relapse is inevitable…
certain changes effected during treatment will tend to
revert toward their original position.
Recovery based on concept of overcorrection, is
indicated on clinical experience & research.
Tweed- Merrifield posterior disclusion :
This is achieved at the end of treatment
Called as “Tweed occlusion” or “transient occlusion”
characterized by disclusion of second molars.

182. The mesiolingual cusp of the maxillary first molar is
seated in the central fossa of the mandibular first
molar with the mesial inclined plane of the mesial cusp
of the maxillary first molar contacting the distal
inclined plane of the mesial cusp of the mandibular
first .
This allows the muscles of mastication to exert the
greatest force on primary chewing table in the
midarch area.
 The slightly intruded distally inclined maxillary and
mandibular second molars now can reerupt to healthy
functional occlusion without trauma or premature
contact

183. "TWEED OCCLUSION,“ "PRIMARY CHEWING TABLE"

184. All bands, except of 1
st
molars and canines are
removed, archwire ligated in both arches
Mandibular arch :canines ligated to each other
Maxillary arch, power chain placed from canine
bracket to other,after7days remaining bands
removed.

185. Muscles of deglutition, mastication and facial
expression are actively involved in determining
the final stable , esthetic relationship of teeth
referred to as functional occlusion.
Each individuals own oral environment will
determine the ultimate position of the dentition.
Thus overtreatment allows patient the opportunity
for maximal stability and functional efficiency

186. Modifications in tweeds mechanotherapy
Literature reveales that certain modifications have
been tried by many clinicians and deviations have
ensued over the years from the basic Tweed's
mechanotherapy.
Harry Bull (1959) presented his bull technique
with modification of Tweed's original procedure.
His concept of treatment for Class II division 1
malocclusion was that correction must rely chiefly
on tooth movement for correction of arch
relationships without putting heavy demands on
anchorage preparation.

187. Ricketts (1971) came out with his bioprogressive therapy
having edgewise as his background. Bioprogressive therapy
took advantage of biologic progression of growth,
development and function.
Dr Ricketts believed that, the diagnosis and the desired results
should guide in selection and use of mechanical procedures.
Anchorage in bioprogressive therapy generally means
stabilizing and positioning of molars against forces during
various stages of orthodontic treatment. In his technique the
use of utility arch was the starting appliance for class II
division 1 and class II division 2 cases.

188. Angelis(1976) presented amalgamated technique.
The technique combined the biomechanical principles of
both edgewise and Begg techniques for efficient and
controlled tooth movement. Amalgamation of both the
techniques gave positive results and lessened the treatment
time. Correction of the overjet without displacement of the
root apices in the opposite direction can be achieved with
amalgamated technique. Controlled tipping with edgewise
brackets and use of round light wires provides effective
mechanics for corrections of malocclusion.

189. (Dr Kapoor, Dr Gupta Jios 2004)
Certain modifications which were incorporated in
basic Tweed's mechanotherapy during treatment
of Class II division 1 cases, requiring first
premolar extraction are the use of Siamese
brackets against single brackets with eyelets,
highly resilient wires like nitinol, elgiloy, triflex
etc. during the initial stages of treatment.
Edgewise arch wires with second order bends and
hooks soldered distal to lateral incisors were used
to high pull headgears for bite opening.

190. Depending on the status of dentition light round
and rectangular arch wires were used for
retracting canines and incisors with the help of
compressed coil springs and sliding hooks
supported by class II or class 111 elastics and
occipital pull or low pull headgears. The
mechanics was modified from time to time as per
the existing maloclussion situation.

191. They found that
An appreciable uprightening of lower mandibular
incisors was achieved with lingual and labial tipping
movement of the crowns and roots of the mandibular
incisors reflected by a decreased in incisor mandibular
plane angle.
Reduction in the value of ANB angle was mainly brought
about by the retraction of the maxillary incisors.

192. Sufficient decrease in overjet and overbite with
marked improvement in the facial profile was
seen following orthodontic treatment.
Total treatment time was substantially shortened
without compromising on the treatment results.

193. New Protocol Of Tweed-merrifield
Directional Force Technology With Micro
Implant Anchorage

194. It is a useful treatment approach for a patient
with a Class I or Class II dentoalveolar-
protrusion malocclusion.
 It can create a favorable counterclockwise
skeletal change and a balanced face without
patient compliance.
In contrast, headgear force with high-pull J-
hook can obtain similar results but depends on
patient cooperation.

195. Good facial balance was obtained by Tweed-
Merrifield directional force technology with
microimplant anchorage, which provided
horizontal and vertical anchorage control in the
maxillary and mandibular posterior teeth, and
intrusion and torque control in the maxillary
anterior teeth, resulting in a favorable
counterclockwise mandibular response.

196. ( Fig A & B) Denture Preparation, (Fig C) Denture
Correction

Fig A & B) Sequential mandibular anchorage preparation
(Fig C) Denture completion

197. Conclusion
Tweed technique is more than just the application of
headgear forces to cuspids.
It is a group of integrated force systems designed to
place the teeth, individually and collectively, in
positions of physiologic and esthetic harmony with their
environment.
It is designed to achieve individualized tooth
movements and precision to each patient,
to achieve functional occlusion and optimal esthetics,
to shorten treatment duration through use of
sophisticated force systems.

198. It respects the dimensions of the denture.
One must discard the idea that a bracket
manufacturer can determine what is best for
orthodontic patients.

199. ‘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.
Undiscovered possibilities are still to be brought forth,
from this device to aid the specialist in difficult corrective
procedures. However, it is necessary to constantly bearing
mind the basic philosophy and concepts of the edge wise
appliance as originally presented by Dr. Angle. Dr. Angle. The basic
concepts are still the key success with its use.
 

200. REFERENCES
Clinical orthodontics…..Charles Tweed, vol 1
Tweed Merrifield Color Atlas
Current orthodontic concepts and techniques…2nd ed.
Graber, Swain
Orthodontics: Current Principles Techniques…4th ed. Graber,
Vanarsdall
Proffit – Contemporary Orthodontics, III Ed
Seminars in orthodontics, Vol. 2, No. 4
Am J Orthod Dentofacial Orthop 2006;130:100-9
 

201. Graber And Vanarsdall 2
nd
And 3
rd
Editions
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

202. THANK YOU