2. Bracket variations
Various suggestions have been
made regarding bracket
choice and positioning to optimize
tooth position when
teeth are absent or where an attempt
is made to
overcome a local problem of tooth
position. The aim
is to reduce the need for archwire
adjustments or
auxiliaries.
4. Careful bracket selection and positioning
simplifies the treatment of localized anomalies in the
following situations:
Class II division 1 malocclusion with lateral incisors
palatally displaced;
absent lateral incisor: space closure;
Class III malocclusions: canine angulation;
Npalatally displaced canine: labial movement;
Nabsent upper central incisors: space closure;
N Class III: incisor inclination.
Bracket variations
5. Andrew’s Six Keys to Normal Occlusion
Lawrence Andrew, in 1972,12
outlined six keys to normal
occlusion after studying 120 non-
orthodontic models and
comparing them with the best
1150 finished orthodontic cases.
The established six keys where
not only purposeful due to its
presence in all 120 orthodontic
normals, but also due to the fact
that in treated models, the
absence of one of the six was able
to predict defective incomplete
end result.
Normal occlusion
6. Key I: Molar Relationship
The first of the six keys is
molar relationship.
1. The distal surface of the
distobuccal cusp of the
upper first permanent
molar occluded with the
mesial surface of the
mesiobuccal cusp of the
lower second molar .
Key I molar relation. (A) Improper molar relationship.
(B) Improved molar relationship. (C) More improved
molar relationship. (D) Proper molar relationship
7. Key I: Molar Relationship
The first of the six keys is molar
relationship.
1. It is possible for the
mesiobuccal cusp of the
upper first year molar to
occlude in the groove
between the mesial and
middle cusps of the lower
first permanent molar, while
leaving a situation
unreceptive to normal
occlusion.
Key I molar relation. (A) Improper molar relationship. (B)
Improved molar relationship. (C) More improved molar
relationship. (D) Proper molar relationship
8. Key I: Molar Relationship
The first of the six keys is molar
relationship.
1. The closer the distal
surface of the distobuccal
cusp of the upper first
permanent molar
approaches the mesial
surfaces of the mesiobuccal
cusp of the lower second
molar, the better the
opportunity for normal
occlusion.
Key I molar relation. (A) Improper molar relationship. (B)
Improved molar relationship. (C) More improved molar
relationship. (D) Proper molar relationship
9. 2. The mesiobuccal cusp of
the upper first permanent
molar fell within the groove
between the mesial and
middle cusps of the lower first
permanent molar.
3. The canines and premolars
enjoyed a cusp–embrasure
relationship buccally, and a
cusp–fossa relationship
lingually.
Key I: Molar Relationship
The first of the six keys is molar
relationship.
Key I molar relation. (A) Improper molar relationship. (B)
Improved molar relationship. (C) More improved molar
relationship. (D) Proper molar relationship
10. Key II crown
angulation
or tip: Long
axis of
crown
measured
from line 90°
to occlusal
plane
Key II: Crown
Angulation, The
Mesiodistal Tip
• The term crown
angulation refers to
angulation (or tip) of
the long axis of the
crown, not to
angulation of the long
axis of the entire
tooth.
.
11. Key II
crown
angulation
or tip:
Long axis
of crown
measured
from line
90° to
occlusal
plane
Key II: Crown
Angulation, The
Mesiodistal Tip
• • The gingival
portion of the long
axis of each crown
was distal to the
incisal portion,
varying with the
individual tooth
type.
12. Key II: Crown
Angulation, The
Mesiodistal Tip
• The long axis of the
crown for all teeth,
except molars, is judged
to be the mid-
developmental ridge,
which is the most
prominent and innermost
vertical portion of the
labial or buccal surface
of the crown.
13. Key II: Crown
Angulation, The
Mesiodistal Tip
The long axis of
the molar crown is
identified by the
dominant vertical
groove on the
buccal surface of
the crown.
14. Key II crown angulation or tip:
Long axis of crown measured
from line 90° to occlusal plane
Key II: Crown Angulation, The
Mesiodistal Tip
Crown tip is expressed
in degrees, plus or
minus. The degree of
crown tip is the angle
between the long axis
of the crown (as viewed
from the labial or
buccal surface) and a
line bearing 90° from
the occlusal plane.
15. Key II: Crown Angulation, The
Mesiodistal Tip
A ‘plus reading’ is
assigned when the
gingival portion of the
long axis of the crown
is distal to the incisal
portion and a ‘minus
reading’ when the
gingival portion of the
long axis of the crown
is mesial to the
incisal portion.
16. Normal occlusion
is dependent
upon proper
distal crown tip,
especially of the
upper anterior
teeth since they
have the longest
crowns.
Key II: Crown Angulation,
The Mesiodistal Tip
17. The degree of the tip
of incisors
determines the
amount of
mesiodistal space
they consume and,
therefore, has a
considerable effect
on posterior
occlusion as well as
anterior esthetics .
Key II: Crown Angulation,
The Mesiodistal Tip
18. Key II: Crown
Angulation, The
Mesiodistal Tip
In normal
occlusion, the
crown
angulation was
positive for all
teeth
19. Key II: Crown Angulation, The Mesiodistal
Tipaccording to Andrew
20. Key III: Crown Inclination
(Labiolingual or Buccolingual
Inclination)
Crown inclination refers
to the labiolingual or
buccolingual inclination
of the long axis of the
crown, not to the
inclination of the long
axis of the entire tooth .
The inclination of all the
crowns had a consistent
scheme.
Key III crown inclination is determined
by the resulting angle between a line 90°
to the occlusal plane and a line tangent
to the middle of the labial or buccal
clinical crown. (A) shows tooth with
positive crown torque and (B) shows
tooth with negative torque .
21. Key III: Crown Inclination (Labiolingual or
Buccolingual Inclination)
Anterior teeth (central and
lateral incisors): Upper and
lower anterior crown
inclination was sufficient to
resist overeruption of anterior
teeth and also to allow proper
distal positioning of the
contact points of the upper
teeth in their relationship to the
lower teeth, permitting proper
occlusion of the posterior
crowns.
22. Key III: Crown Inclination (Labiolingual or
Buccolingual Inclination)
A, Improperly inclined anterior crowns result in all upper contact points being mesial,
leading to improper occlusion. B, Demonstration, on an overlay, that when the anterior
crowns are properly inclined the contact points move distally, allowing for normal
occlusion.
23. Key III: Crown Inclination (Labiolingual or
Buccolingual Inclination)
Spaces resulting
from normally
occluded posterior
teeth and
insufficiently
inclined anterior
teeth are often
falsely blamed on
tooth size
descrepancy.
24. Key III: Crown Inclination (Labiolingual
or Buccolingual Inclination)
In normal
occlusion, the
crown inclination
for all teeth was
negative except
maxillary central
and lateral incisors
25. Key III: Crown Inclination
(Labiolingual or Buccolingual
Inclination)
Upper posterior teeth
(canines through
molars): A lingual crown
inclination existed in the
upper posterior crowns.
It was constant and
similar to the canines
through the second
premolars and was
slightly more
pronounced in the
molars.
26. Key III: Crown Inclination
(Labiolingual or Buccolingual
Inclination)
Lower posterior
(canines through
molars): The
lingual crown
inclination in the
lower posterior
teeth progressively
increased from the
canines through
the second molars.
27. Tip and Torque
The clinical
implication of
the tip and
torque is that
they collectively
affect the upper
anterior crowns
and total
occlusion.
Andrew’s wagon
wheel concept. (A, B)
Unbent rectangular
archwire with vertical
wires soldered at 90°,
spaced to represent
the upper central and
lateral incisors. (C–E)
As the anterior
portion of the
archwire is torqued
lingually, the vertical
wires begin to
converge until they
become the spokes
of a wheel when the
archwire is torqued
90° progressively.
28. Tip and Torque
In lingual crown
torque, for every 4˚,
there is 1˚ mesial
convergence of
central and lateral
incisor crowns, at the
gingival portion. The
ratio is approximately
4:1. Andrew described
this phenomenon as
the ‘wagon wheel
concept’
Andrew’s wagon wheel
concept. (A, B) Unbent
rectangular archwire
with vertical wires
soldered at 90°, spaced
to represent the upper
central and lateral
incisors. (C–E) As the
anterior portion of the
archwire is torqued
lingually, the vertical
wires begin to converge
until they become the
spokes of a wheel when
the archwire is torqued
90° progressively.
31. The orthodontist
is often called
upon to correct
upper lateral
incisors which
are palatally
displaced.
Bracket variations
1-upper lateral incisor
palatally displaced
and/in crossbite
32. Cases with upper
anterior crowding
on Class 1 or Class
III dental bases
are liable to have
upper lateral
incisors which are
in crossbite, and it
can be difficult to
achieve stable
root correction.
33. upper or lower lateral incisor palatally or lingually displaced
35. Class IIdivision 2 WITH DISPLACED UPPER RIGHT LATERAL
INCISOR PALATALLY AND IN CROSS BITE .
36. Where the maxillary
lateral incisors
have erupted
palatally, often the
most
challenging and
time-consuming
treatment objective
is labial movement
of
the roots of these
teeth.
37. Class II Division 1 malocclusion
maxillary lateral incisors have
erupted palatally,
41. In some Class II
division 1
malocclusions,
the upper lateral
incisors may be
palatally
displaced.
Orthodontic
treatment
aims to align both
crown and root;
42. This is
complicated
further by the fact
that the torque
prescription
of the upper lateral
incisor favours
palatal root torque.
To address
this, the lateral
incisor bracket can
be inverted.
Upper Laterals
Torque Values
43. Torque or root
movement is
achieved by keeping
the crowns
stationary and
applying a moment
to force only to the
root. The center of
rotation of a tooth is
at the incisal edge in
case of root
movement
44. The effect of
this is to
change
the torque
prescription of
the bracket to
promote labial
movement of
the root.
Using upside down Roth brackets
in the upper lateral incisor is a
simple way to get more labial root
torque with classic Roth brackets.
46. There is a risk of
moving the crown
labially, while leaving
the root palatally
placed. In this
situation, there will be
a need for additional
wire bending, and
treatment time will be
extended.
47. Labial root torque
may be introduced
into the
archwire with
torquing pliers (e.g.
Rose torquing
pliers)
or by a single tooth
torquing auxiliary.
Bracket variations
48. A simpler solution, however,
is to invert the lateral
bracket. At the start of
treatment bracket inversion
maintains the crown
angulation, but boosts(
facilitates ) labial
torque by reversing slot
inclination. This approach
may also increase patient
comfort by gradual
introduction
of labiolingual torque..
Inverted upper lateral incisor
brackets give -10° torque and
+8° angulation in cases with in-
standing laterals.
49. In cases with palatally displaced upper lateral incisors, it is
beneficial to invert the upper lateral incisor brackets to create -10°
torque instead of +10° of torque .This creates the necessary labial
root torque to aid in moving the lateral root forward
50. Inverted upper lateral
incisor bracket
applying additional
root torque to an
instanding left lateral
incisor. The right-side
bracket
is placed in the normal
position. Note the
more labial position of
the root apex when the
bracket is inverted,
reversing the torque.
51. Inverted upper lateral incisor
brackets give -10° torque and +8°
angulation in cases with in-
standing laterals. ... It shows the
slightly increased prominence of
the upper lateral incisors,
resulting from the reduced in-out
on the brackets.
in-out
52. Effective torque
however,
depends on the
bracket prescription.
Before
bracket positions
are modified the
prescription of the
brackets must be
known.
MBT™ Versatile+ Appliance System
53. It is not correct to
switch sides. The left
bracket goes on to the
left incisor and the
right bracket on to the
right incisor. Inverting
the bracket in this way
applies effective labial
root torque at the
rectangular wire stage,
for easy root
correction.
54. The palatally displaced
lateral incisor is
bracketed with the
normal bracket, but it is
rotated 180° , which
changes the torque from
+10° to-10°. This assists
in labial root torque at
the rectangular wire
stage. The tip stays the
same at 8°.
Conventional placement of an upper lateral incisor
Rotation of the lateral incisor bracket by 180°
bracket gives +10° of torque. changes the torque from +10° to -10°
55. The left side bracket is
placed on the left incisor
and the right side
bracket is placed on the
right incisor. This is
mentioned because it is
a frequently asked
question! It is not correct
to place the left incisor
bracket on the right
incisor or vice versa
Conventional placement of an upper lateral incisor
Rotation of the lateral incisor bracket by 180°
bracket gives +10° of torque. changes the
torque from +10° to -10°
56. A convenient way to
manage INSTANDING
UPPER LATERAL
INCISORS cases involve
the following
procedures:
• During the alignment
stage, it is necessary to
create enough space
for the palatally
displaced tooth.
57. This is achieved
using coil spring.
The brackets on
the adjacent
teeth are tied
with wire
ligatures, to
prevent rotations
58. It is necessary to create
sufficient space for
palatally displaced
incisors before
attempting to move
them labially.
Bendbacks are placed 2
mm distal to molar
tubes, to allow an
increase in arch length.
59. After creation of
space, a .015
multistrand wire
or a .016 HANT
wire may be used
to gently move the
lateral incisors
labially
61. The alternative is wire
bending, but it is
difficult and time
consuming to introduce
the exact amount of
torque needed into
rectangular wire.
Inverting the bracket is
more precise and easier.
In cases with instanding upper lateral incisors it is
often helpful if the bracket is inverted.
An occlusal view of a case, close to completion. It shows
the slightly increased prominence of the upper lateral
incisors, resulting from the reduced in-out on the
brackets. This gives better smile aesthetics, which is
much appreciated by patients
62. In the Andrews
prescription a lateral
incisor bracket
with a 3 degrees of
torque when inverted
delivers an inclination,
which was increased by 6
degrees (from –3 to 3
degrees with the
standard bracket
prescription).
Andrews/Roth/MBT torque values
63. Inverted Roth
lateral incisor brackets
produce a difference of 16
degrees
compared with 6 degrees
with Andrews prescription as
normally positioned .Roth
lateral brackets have 8
degrees of
palatal root torque
incorporated into their
design.
Andrews/Roth/MBT torque values
64. An MBT bracket
inverted on a lateral
incisor changes
torque by 20 degrees
as 10 degrees changes
to -10 degrees. Full
bracket
expression is unlikely
with the archwire
dimensions used
in clinical practice.
Andrews/Roth/MBT torque values
66. Inverted upper
lateral incisor
bracket applying
additional root
torque to an
instanding left
lateral incisor. The
right-side bracket
is placed in the
normal position.
(a)
Apical view.
67. (c) Incisal view.
Note the
more labial
position of
the root apex
when the
bracket is
inverted,
reversing the
torque.
68. 2-Absent lateral
incisors: space closure
When maxillary
lateral incisors
are absent and
space
closure is
planned, which
bracket is best
placed on the
canine?
69. Absent lateral incisors:
space closure
The standard MBT
canine bracket has
7 degrees of
labial root torque,
which is
appropriate for a
canine in
its usual position in
the line of the arch.
Torque Values
70. Absent lateral incisors: space closure
This is
inappropriate, however,
if this tooth is to
replace a
lateral incisor where
palatal root torque is
indicated,
rather than labial
torque.
the canines receive the lateral incisor brackets.
canines extrusion and premolars
intrusion to adjust the gingival level.
the canines should receive, lingual
root torque .The first premolars
receive canine brackets
A multidisciplinary
treatment of
congenitally missing
maxillary lateral
incisors: a 14-year
follow-up case report
J Appl Oral Sci.
2014;22(5):465-71
71. Absent lateral incisors: space closure
One suggestion is to place a
lateral incisor bracket on the
canine crown. However,
the height of the bracket
stem and the labiolingual
thickness may be too great,
and may position the tooth
palatally in the line of the
arch unless first order
bends
are also incorporated.
Prescription in Roth technique
Torque Values
Tip Values
72. Absent lateral incisors:
space closure
Also there
may be
insufficient
torque in view
of the greater
crown-root
angle found
in
canines.
Torque Values
The collum angle
and the crown to
root angulation
73. Absent lateral incisors:
space closure
Bracket fit
creates a
further
problem as
canine
crown labial
convexity is
greater than
that of the
lateral
incisor.
Torque Values
Upper lateral incisor bracket.
74. Lateral incisor brackets were placed on the upper canines
to allow a more palatal root torque and reduce the canine
eminence. The upper first premolar brackets were bonded
in a slightly distal position which will rotate the premolars
mesially for better esthetics.
76. Lateral brackets may be placed on
canines when treating patients with
canine substitution , positioned
according to gingival margin height
rather than on the cusp tip of the
substituted canines .
The brackets on the substituted canines
should be placed at a distance from the
gingival margin such that they will erupt
these teeth to the appropriate lateral
incisor vertical height .
77. To substitute canines in the
position of missing laterals,
special bracket placement
was necessary for both
maxillary canines and the
first premolars. The lateral
incisor brackets were bonded
to the canines and the canine
brackets were placed on the
first premolars.
78. Before bonding the
lateral incisor bracket on
the canine, the labial
surface was reshaped for
the bracket adaptation. It
is necessary to position
these brackets gingivally
to permit the
recontouring of the
canines required for
esthetics and function.
Recontouring (red color) of the
maxillary canine to resemble like
a lateral incisor.
79. To make the canine
appear less curved
and more like a
lateral incisor, the
bracket was placed
more distally in the
center of the canine
rather than at the
height of contour
80. In addition, a
canine bracket
was placed on
the first premolar
in the same
mesiodistal
position (more
distally) in which
it is placed on
the canine.
81. However, to
improve the
interproximal
contact points,
offset bonds (in-
out) was needed
between the
central incisor
and canine .
In the archwire design, to improve the
interproximal contact points, the 1st
order (in-out) bends was performed
on the maxillary canines.
82. A. Recontouring (red color) of the maxillary canine to resemble
like a lateral incisor. B. Recontouring (red color) of the prominent
labial ridge of canine before bonding a bracket. The lingual
surface was reduced (blue color) to establish a balanced
occlusion. B. The lingual cusp of the maxillary first premolar for
canine substitution was recontoured (blue color).
83. Absent lateral incisors: space closure
Regarding the solution of
placing a lateral incisor
bracket after
recontouring of the canine
to mimic the lateral incisor,
potential obstacles are the
wide range of canine
crown
anatomies and
unfavourable crown-root
angulations.
84. Maxillary canine, labial aspect. Maxillary canine, mesial aspect.
the wide range of canine crown
anatomies
86. Maxillary canine. Ten specimens with
uncommon variations are shown. 1,
Crown very long, with extreme curvature
at apical third of the root. 2, Entire tooth
unusually long. Note hypercementosis at
root end. 3, Very short crown; root small
and malformed. 4, Mesiodistal
dimension of crown at contact are
extreme; calibration at cervix narrow in
comparison; root short for crown of this
size. 5, Extreme labiolingual calibration;
root with unusual curvature. 6, Tooth
malformed generally. 7, Large crown;
short root. 8, Root overdeveloped and
very blunt at apex. 9, Odd curvature of
root; extra length. 10, Crown poorly
formed; root extra long.
87. Absent lateral incisors: space closure
An alternative is to invert the
canine bracket on the
canine tooth. This achieves a
crown angulation of 11
degrees,
but 7 degrees labial root
torque becomes 7 degrees of
palatal root
torque for both MBT and
Andrews prescription, but
slightly less for Roth
brackets due to the
prescription.
Torque values for the three bracket
prescriptions (degrees).
Angulation prescription (in degrees) with
popular pre-adjusted edgewise prescriptions.
Positive values indicate mesial crown tip
88. Absent lateral incisors:
space closure
The canine bracket is
compound contoured to fit
the
crown surface; the bracket
stem height is unchanged.
Tip may be excessive
where a canine is replacing
a
lateral incisor. Canine tip
varies between different
prescriptions .
Torque values for the three bracket prescriptions
(degrees).
Andrews/Roth/MBT tip values
89. Absent lateral incisors: space closure
In the MBT
prescription, the
tip value is identical
for both the lateral
incisor and the
canine. In the Roth
prescription there is
a 5 degrees
difference
and with the Andrews
there is a difference
of 3 degrees.
Andrews/Roth/MBT tip values
90. Absent lateral incisors: space closure
Therefore, a Roth
bracket (with 13
degrees of tip when
inverted
onto a canine replacing
a lateral incisor)
delivers 4 degrees of
additional tip beyond
the norm for a lateral
incisor.
Andrews/Roth/MBT tip values
91. Case Report Orthodontic Space Closure of a Missing Maxillary
Lateral Incisor Followed by Canine Lateralization
Hindawi Case Reports in Dentistry Volume 2020, Article ID
8820711, 7 pages https://doi.org/10.1155/2020/8820711
class I molar
relationship
bilaterally, missing
left maxillary lateral
incisor, upper right
peg lateral incisor,
and gap between the
teeth in the upper
front region
92. Case Report Orthodontic Space Closure of a Missing Maxillary
Lateral Incisor Followed by Canine Lateralization
Hindawi Case Reports in Dentistry Volume 2020, Article ID
8820711, 7 pages https://doi.org/10.1155/2020/8820711
The canine brackets
on the upper left
side are inversed to
have +7° torque on
the left upper
canine which
matches nearly with
the torque of the
upper lateral incisor
tooth.
Torque values for the three bracket prescriptions (degrees).
93. Case Report Orthodontic Space Closure of a Missing Maxillary
Lateral Incisor Followed by Canine Lateralization
Hindawi Case Reports in Dentistry Volume 2020, Article ID
8820711, 7 pages https://doi.org/10.1155/2020/8820711
Apart from this, the bracket on
the upper left canine is
positioned slightly gingivally to
match with the gingival zenith
of the contralateral lateral
incisor. The first premolar
bracket is positioned slightly
distal to hide the palatal cusp
of the first premolars on the
left side and to give the cervical
prominence as that of the
canine.
94. 3-Canine WITH
gingival recession
In cases where the
gingivae has receded or
the canine is very
prominent, inverting
the
bracket gives palatal
root torque, which can
help reduce further
recession Torque Values
Torque values for the three bracket
prescriptions (degrees).
95. Orthodontic
camouflage is carried
out when a Class III
malocclusion is treated
by accepting the
skeletal pattern;
orthodontic appliances
tilt the upper and lower
incisors
to compensate for the
skeletal discrepancy.
4-Canine angulation in
Class III cases
97. It has
been suggested
that contra-
lateral canine
brackets on
the lower
canines
encourage the
crowns to tip
distally.
(a) Contra-lateral brackets placed upon the lower
canines. The crowns are tipped distally. (b) Clinical
photograph with lower
canine brackets transposed to achieve dental
camouflage in a Class III malocclusion
Canine angulation in
Class III cases
Torque values for the three
bracket prescriptions (degrees).
Andrews/Roth/MBT tip values
98. In some Class III
treatments it is
helpful to switch
left and right
lower canine
brackets. This
changes the tip
from +3° to -3°
and
can make the
mechanics
easier.
Tip Values
99. Canine
angulation in
Class III cases
Dentoalveolar
compensation
is facilitated
and
anchorage
requirements
are reduced.
Transposed MBT
brackets attached to
mandibular canines
100. Canine angulation in
Class III cases
The outcome of bracket
transposition will
depend on the bracket
prescription. In the
Andrews
prescription 5 degrees
tip becomes a 10 degrees
difference; with MBT
3 degrees becomes a 6
degrees difference.
Andrews/Roth/MBT tip values
101. 5-Labial movement of palatal
canine
Palatal canine movement
results in crown movement
without the root, causing
unattractive
tip. In order to increase
labial root torque, the lower
contra-lateral canine bracket
can be
inverted to the upper. This is
relevant in Roth where there
is 9° change; in MBT there
are
similar torque values.
Torque values for the
three bracket
prescriptions (degrees).
102. 5-Labial movement of a
palatal canine
When a palatally
displaced canine is
moved labially,
movement of the
crown may occur in
advance of the
root leaving it
unattractively
tipped. Increased
labial
root torque
overcomes this.
Inclination/torque prescription (in degrees) with popular pre-adjusted edgewise
prescriptions.
Positive values indicate palatal root torque
103. 5-Labial movement of a
palatal canine
One option
is to invert
the
lower contra-
lateral canine
bracket onto
the upper
canine.
Inclination/torque prescription (in degrees)
with popular pre-adjusted edgewise
prescriptions.
Positive values indicate palatal root torque
104. 5-Labial movement of a
palatal canine
The MBT
prescription in
this case would
provide no
benefit as the
torque values
are similar for
the upper and
lower canines.
Canine bracket inverted on
the upper right canine
105. 5-Labial movement
of a palatal canine
Roth and Andrews
prescriptions, however,
would provide a small
benefit,
as there is a difference
of 9 and 4 degrees,
respectively. The
additional labial root
torque may, therefore,
help to
correct tooth position .
Inclination/torque prescription (in degrees) with
popular pre-adjusted edgewise
prescriptions.
Positive values indicate palatal root torque
106. 6-Absent upper central
incisor
In order to
facilitate
restorative
treatment, the
preferential
mesial root
movement over
the
crown should
occur.
Inclination/torque prescription (in degrees)
108. A central incisor
bracket should be
placed on a mesially
substituted lateral
incisor to achieve an
appropriate
angulation ( tip) for
the labial surface of
the incisor, as well as
to better control its
rotation, and correct
the second order axial
inclination.
Tip Values
Torque Values
109. The emergence
profile of a maxillary
central incisor is
generally flat on the
mesial surface, but
the adjacent lateral
incisor is more
angulated . When
substituting a lateral
for a central incisor,
it is necessary to
move it close to the
midline to provide a
more natural midline
papillae.
110. Angulation/ Inclination/ Crown Size
Compared to normal
tooth form (right),
angulation (2
degrees ) and
mesiodistal
positioning of the
substituted lateral
incisor is essential
for simulating the
midline papilla and
central incisor crown
form (left).
111. Angulation/ Inclination/ Crown Size
The mesially substituted teeth were
altered restoratively to simulate
upper left incisors and canine. Note
that the primary consideration is
aligning the gingiva and papillae.
Once there axial inclinations were
corrected, restorative procedures
were performed.
Because of the size
difference
between the
incisors , the
lateral incisor must
be extensively
recontoured on
the distal surface
which may or may
not be consistent
with periodontal
health.
Missing Maxillary Central Incisor Treated with Mesial
Substitution of the Lateral Incisor, Canine and First Premolar
iAOI CASE REPORT
112. lateral incisor in the
space for restorative
purposes claiming this
improves force
transmission through the
root
Bonding the
contralateral central
incisor bracket to tilt
the tooth
allows this ; however,
some clinicians
prefer centring the
Tip Values
113. 6-Absent upper central
incisor: space
closure
Following loss of
an upper central
incisor, space
closure
may involve
moving the lateral
incisor mesially.
The
lateral then abuts
the adjacent
central incisor..
114. 6-Absent upper central incisor:
space
closure
As the
lateral moves
mesially, its
root should
move further
mesially than
its crown; the
mesial surface
is then
vertical.
The mesially substituted teeth were
altered restoratively to simulate
upper left incisors and canine. Note
that the primary consideration is
aligning the gingiva and papillae.
Once there axial inclinations were
corrected, restorative procedures
were performed.
115. 6-Absent upper central incisor: space
closure
This permits the
restorative phase to
build up
the distal surface with
an optimal emergence
profile.
This avoids the
problem of retention
from a mesiogingival
margin on the
restoration.
116. 6-Absent upper central
incisor: space
closure
It has been
suggested that it is
useful to bond the
contra-lateral central
incisor
bracket to tilt the
tooth so its distal
crown aspect
approaches vertical.
117. 6-Absent upper central
incisor: space
closure
Contra-lateral central
incisor bracket placed
on the
upper left lateral
incisor. Note the
exaggerated tip, which
brings
the mesial surfaces
together and allows
build up of the distal
emergence profile
Upper
canine brackets are
inverted to provide
additional palatal root
torque. The lateral
incisor brackets are
transposed to
achieve
improved root
paralleling prior to
mesial movement
and restorative
build-up
Inclination/torque prescription (in degrees)
118. • For good root control
with buccally ectopic
upper canines, the
-7° torque bracket is not
really suitable, and
works better when
inverted to give the +7°
option, which guides
the root into cancellous
bone.
Torque Values
7-Buccally
ectopic canine
119. In class 3 cases, there
is a need for upper
incisor proclination. It
is possible to invert
incisor
brackets for labial
root torque, MBT
giving the greatest
change at 34°
although there are
concerns that this
amount of torque
risks root resorption.
8-Incisor inclination In
class III
120. 8-Incisor inclination in Class III
malocclusions
When Class III
malocclusions
are treated
orthodontically
the upper
incisors tend to
be proclined as
the
malocclusion is
camouflaged.
121. 8-Incisor inclination in Class III
malocclusions
Subtelny and
Catania
advocated the use
of labial root
torque and tying
the
archwire forward to
advance ‘A’ point
and boost
anteroposterior
arch length.
The forward arch must be
separated 2 mm from
the slots of the anterior
braces.
Lateral view of the stop and
the separation
of the wire from the slot of
the braces.
122. It can be helpful
to invert lower
incisor brackets
(to give +6°
torque) in some
Class III cases to
prevent
unwanted
retroclination
of lower
incisors.
Torque Values
It is helpful to invert
the lower
incisor brackets in
some cases.
123. This can also
be useful in
cases where
molar
anchorage
loss is needed
or where a
single lower
incisor
is proclined.
Torque Values
It is helpful to invert
the lower
incisor brackets in
some cases.
124. IN THIS CLASS
III IT IS NOT
ADVOCATED
TO PROCLINE
THE UPPER
INCISORS
DURING
ORTHODONTIC
CORRECTION
125. DO NOT PROCLINE THE UPPER INCISORS DURING
ORTHODONTIC CORRECTION
126. 8-Incisor inclination in Class III
malocclusions
The possibility
exists to
invert incisor
brackets and use
these to provide
labial
root torque, which
may be useful in
some selected
cases.
127. 8-Incisor inclination in Class III
malocclusions
For the central incisors
this would effectively
change the
torque values: Andrews (a
14 degrees change), Roth
(a change of 24 degrees),
and MBT (a
change of 34 degrees).
128. 9-Upper premolar
substituting canine
In cases where the canine is
absent or replacing the
lateral incisor, placement of
the bracket
more distally on the
premolar moves the palatal
cusp out of the way .
Smoothing the palatal cusp
of the first premolar may be
required to further hide it or
improve occlusal
interference.
Two supernumerary
teeth were observed between the lateral incisors and
first premolars. The maxillary permanent canines were
impacted over the roots of the upper central incisors.
Substitution of retained canines with first
maxillary premolars. Case report
Revista Mexicana de Ortodoncia
Vol. 4, No. 4 October-December 2016
129. Treatment plan
• Removal of the maxillary canines and replace
them
with the first premolars because these had the
necessary size and root shape to achieve lingual
crown torque.
• Substitute canine guidance with premolar
guidance
or group function.
• Placement of 0.022” x 0.025” slot Roth fixed
appliances.
• Final articulation mounting in order to perform
the
occlusal adjustment and for the premolars to
better
withstand the occlusal loads.
• Rehabilitation with interproximal resins in the
lateral
incisors and premolars to achieve an adequate
periodontal health
130. 10-Case finishing
In order to achieve good
finishing and occlusion in
MBT prescription, lower
second molar
tubes can be used on the
contralateral upper first and
second molars to result in
zero tip
and zero rotation,
resulting in mesio-palatal
rotation of upper molars.
131. Upper second molars:
Usually, a step
between first
and second molar
occurs . To avoid this
step, it is important to
understand how these
teeth are
in a normal situation.
10-Case finishing
(a and b) An
undesirable
step between
the first and
second
upper molar
132. Upper second molars:
10-Case finishing
By analyzing the position
and
inclination of the second
molars in a collection of
skulls
with normal occlusion, it is
found that these teeth are in
a more distocervical
direction to the occlusal
plane and
at a slight angle to distal .
Observe the position of the second
molars in a collection of skulls with
normal occlusion. These teeth are in a
more superior position to the
occlusal plane and at a slight angle to the
distal
133. It seems that the
position of these teeth
is a little
different from what is
common to mount
orthodontic
appliances. Therefore,
the clinical crowns of
the second
molars are always
angulated in
distocervical direction[
Observe the position of the second molars in a
collection of skulls with normal occlusion. These
teeth are in a more superior position to the
occlusal plane and at a slight angle to the distal
10-Case finishing
134. One can
observe the
same situation
illustrated in
Angle’s book,
as a normal
occlusion .
Normal occlusion
illustrations from
the Angle’s book
(1907). The
same characteristic
position of second
molars can be
observed
10-Case finishing
135. Klontz also emphasizes this
condition in a very
clear way in his article–
“Readout.” Thus, to have no
problems in positioning the
brackets and tubes on upper
second molars, it is
necessary to follow the
precepts:
(1) hold tooth in its normal
position, (2) position the
bracket as occlusal as
possible, and (3) control
torque
10-Case finishing
136. A 25-year-old female
patient presented at
the office for a
second opinion as
she had been advised
to undergo
orthognathic surgery
in order to resolve
her complaint.
Patient’s smile at initial appointment. Notice the
canted occlusal plane from the right to
the left side.
11-Canting of the
occlusal plane
137. She had a mild frontal
asymmetric face, but
her only complaint was
the asymmetric
superior occlusal
plane, notably on
smiling, and
consequently the lower
arch followed these
upper disharmonies,
but to a lesser extent .
Patient’s smile at
initial appointment.
Notice the canted
occlusal plane from
the right to the left
side.
11-Canting of the occlusal plane
138. Initial intraoral
photograph.
Notice the canted
occlusal plane
from the right to
the left side.
She presented
with a Class I
relationship
and mild lower
teeth crowding
that could be
solved by
stripping
11-Canting of the occlusal plane
139. Ceramic
standard
edgewise
0.022” x
0.028”
orthodontic
brackets were
placed on all
teeth.
Individualized vertical bonding of maxillary
brackets: the brackets on the right side
were bonded at a higher position from the
incisal/occlusal edge and at a lower
position on the left side
11-Canting of the occlusal plane
140. The brackets on the
upper right side were
bonded at a higher
position from the incisal/
occlusal edge and at a
lower position on the left
side following a correct
height relationship
between them (i.e.: the
lateral incisors placed
0.5mm more incisally
than the central incisors)
ndividualized vertical bonding of maxillary brackets: the
brackets on the right side were bonded at a higher
position from the incisal/occlusal edge and at a lower
position on the left side
11-Canting of the occlusal plane
141. Orthodontic leveling of the
maxillary and mandibular arches
were performed with nickel-
titanium 0.014” and heat-activated
0.019” x 0.025” wires.
Individualized stainless steel
0.019” x
archwires were placed. The
maxillary archwire received a
substantial lingual crown torque in
the left posterior side to counter
the effects of intrusion, while force
was applied outside the center of
resistance of these teeth.
0.026”
11-Canting of the occlusal plane
The appliance was mounted
according to the malocclusion. The
height of the canine bracket from one
side is different to other side with the
leveling resulting in a significant
improvement
142. individualized vertical bonding of maxillary
brackets: the brackets on the right side were
bonded at a higher position from the
incisal/occlusal edge and at a lower position on the
left side
One millimeter
difference in vertical
positioning could alter
torque values up to 10
degrees. Intense
posterior torque was
applied to the left side
of the maxillary
archwire in order to
oppose asymmetric
torque in maxillary
teeth.
11-Canting of the occlusal plane
143. The patient was very
pleased with the
results. A
symmetrical occlusal
plane was obtained
and incisor
angulation corrected.
Therefore, the
proposed objectives
were achieved
Patient at
debonding
appointment.
Patient’s smile at
the end of
treatment.
11-Canting of the occlusal plane
144. 12-Class II cases where anchorage
at a premium in maxillary arch
Maxillary premolar bracket
on
maxillary canine (or
intentional mesial
angulation
of canine bracket)
This limit mesial crown
tipping
and associated anchorage
demand to move root
distally
Tip Values Torque Values
Angle Class II division 1 malocclusion (a) with proclined maxillary
incisors (red line in a), and Angle Class II division 2 malocclusion (b)
with retroclined maxillary central incisors (purple line in b).
145. Thin gingival biotype with
lower labial recession
where
lingual root positioning
may be beneficial
Inversion of MBT™
mandibular incisor
bracket™ will give
Additional lingual
root
torque
Torque Values Tip Values
13 -Gingival recession on the lower incisors
146. 14-Scissors bite where
mandibular
arch expansion may
improve
transverse co-
ordination
Inversion of
mandibular
premolar brackets
gives
additional lingual
root
torque
Tip Values Torque Values