placement of orthodontic brackets

Placement of
orthodontic brackets
Prof.Dr. Maher fouda
Prepared by: Hani alsrooh

A Proper Finish
Begins With a
Proper Start

Perhaps the single-most-
important phase of orthodontic
treatment is proper bracket
placement.

Taking time to achieve proper
placement at the outset can help
mitigate—or even eliminate—
ﬁnal archwire bends and
correction.

Facial Axis of the Clinical Crown
(FACC) .The most prominent
portion of the central lobe on each
crown’s facial surface. For molars,
the buccal groove that separates
the two facial cusps.

Facial Axis Point (FA point) :The
point on the facial axis that
separates the gingival half of the
clinical crown from the occlusal
half.

Andrews® Plane: The surface or
plane on which the mid-transverse
plane of every crown in an arch will
fall when the teeth are optimally
positioned. This plane virtually
connects the appliance through the
FA point.

Upper Arch FA Point & FACC
Upper Arch Brackets On Andrews® Plane Line

Lower Arch FA Point & FACC
Lower Arch Brackets On Andrews® Plane Line

The accurately placed brackets will give better
control on three dimension position of the teeth
during treatment. An accurately placed bracket will
also result in better expression of its built in
prescription and orthodontist will need less wire
bending and complex mechanics during the course
of treatment

Mesiodistal position of brackets
It is a general saying in orthodontics that brackets
should be placed at mesiodistal center of the teeth.
This statement is partially correct as this rule can't be
applied to all the teeth.

Occlusal view of ideal patient setup with
brackets not centered, but teeth aligned. (Note:
lines were added to represent midline of the
tooth.

A more clear description for right mesiodistal
position of brackets was given by Andrew that
brackets should ideally be placed at the mid
developmental ridge of the teeth.

Maxillary and mandibular incisors
Bracket should ideally be placed at mesiodistal center of
maxillary and mandibular incisors. The mid developmental
ridge of these teeth is also present at their mesiodistal
center of the labial surface
.

Maxillary and mandibular incisors

Vertical lines showing mesiodistal center of the
upper and lower incisors. Brackets should be
placed at the recommended height on this line

Maxillary and mandibular Canines

Maxillary and mandibular Canines
Placing brackets at the mesiodistal center of the canines will result in
contact point error and slight rotation of the teeth as the mid developmental ridge
of upper and lower canines lies slightly mesial to the mesiodistal center of
the teeth and is more mesial in case of lower canines. So bracket is placed
slightly off center and toward mesial, in case of canines

bracket is placed slightly off center and toward mesial, in
case of canines

bracket is placed slightly off center and toward mesial, in case
of canines

{
The vertical lines on maxillary and mandibular canines
indicate the mid developmental ridge of the canines and
ideally the middle of the brackets should coincide with this
line.

Mandibular Premolars
Roth purposed that premolars
brackets should be placed at area
of maximum convexity which is
usually the mesiodistal center of
the teeth and mid developmental
ridge also lies in this area.

Sometimes the area of maximum convexity lies slightly
mesial to the mesiodistal center but degree of mesial
deviation is less than that of canines. The difference
between bracket placement on premolars and anterior teeth
is presence of a lingual cusp on premolars which must be
taken into consideration while placing
the brackets.
M D

maximum convexity lies slightly mesial to
the mesiodistal center .The cast of the
patient should be examined to detect
position of the maximum convexity

In mandibular premolars the buccal and lingual
cusps lies at the same level in the mesiodistal
perspective. So when placing
lower premolars brackets the scribe line of the
bracket should coincide with line connecting the
buccal and lingual cusps

A left lower 2nd premolar bracket bonded so that the
line connecting the buccal and lingual cusps passes
through the scribe line of the bracket. This is because
buccal and lingual cusps of the lower premolars should
be present at the same level in mesiodistal perspective

In maxillary premolars, brackets should be placed so that
the scribe line of the bracket is slightly mesial of up to 0.5
mm to the line connecting the buccal and lingual cusps

Maxillary Premolars
Bracket placement on maxillary premolars is different from mandibular
premolars as maxillary premolars should have slightly rotated position at
the end the treatment. while the lingual cusps have cusp fossa
relationship with lower premolars in class I & II molar occlusion

Maxillary Premolars
maxillary premolars should
have slightly rotated position
at the end the treatment.

According to Andrew six keys of normal
occlusion the buccal cusps of upper premolars
should have a cusp embrasure relationship
with lower premolars

According to Andrew six keys of normal
occlusion the buccal cusps of upper
premolars should have a cusp embrasure
relationship with lower premolars

So if the buccal and lingual cusps are in one line
in the mesiodistal perspective then both buccal
and lingual cusps will have a cusp embrasure
relationship with lower dentition. Such a relation is
not acceptable .

According to Andrew1 the buccal
cusps of upper premolars should
be slightly more distal than the
lingual cusps in the mesiodistal
perspective

So in maxillary premolars, brackets should be placed so that
the scribe line of the bracket is slightly mesial of up to 0.5
mm to the line connecting the buccal and lingual cusps

A. Keeping the buccal and lingual cusps of maxillary premolars in the
same mesiodistal perspective will cause poor occlusal results.. D. A
bracket bonded slightly mesial to line connecting the buccal and lingual
cusp of maxillary 2nd premolar. Bonding the bracket in this position will
rotate the buccal cusps
distally and lingual cusp slightly mesial to get ideal relationship in a
class I molar relationship

B&C. When the buccal cusp tips of the
maxillary premolars are in line with lower
embrasures their lingual cusps lies slightly
mesial to embrasures and rest at their
corresponding teeth fossas

According to McNamara such a position will also
help to improve class I & II dental relationships
E &F Like class I in class II molar finished cases maxillary
premolar buccal cusp is slightly distal to lingual cusp in
mesiodistal perspective to give ideal occlusal
relationships

For class III molar finished cases though there are
no guidelines available in the literature but the
auther opinion is that upper premolars should be
bonded like class I cases in surgical and
orthopedic treatment..

But if the orthodontist is aiming class III
camouflage then upper premolar brackets should
be bonded slightly distal to mid developmental
ridge so that the buccal and lingual cusps have the
same prominence in mesiodistal perspective

{
Maxillary and mandibular molars
Conventionally bands are placed on the molars. The most
suitable band is one that snugly fit the tooth. Whether molar
bands or tubes are used, the optimum mesiodistal position
is decided by taking the mesiobuccal cusp as reference.

{
The mesial opening of the
tube should lie below the
mesiobuccal cusp at the
correct vertical height

Bands placed on upper and lower molars. The
mesial opening of the tube lies below the mesiobuccal
cusp of the molars. The rule hold true for both 1st and
2nd molars in both arches

Checking mesiodistal position of the brackets
The mesiodistal position of the bracket can be checked under both direct
and indirect vision. For indirect vision diagnostic mirror is used .
Generally mesiodistal position of upper incisors, premolars and molars
brackets is
checked under indirect vision

The mesiodistal position of
the bracket can be checked
under both direct and indirect
vision For indirect vision
diagnostic mirror is used

Modifications in mesiodistal position of the bracket
Alteration in mesiodistal position of the bracket will alter the
prescription of the bracket in terms of counter rotation.
Some situations where mesiodistal position of the bracket is
altered are given.

Rotated teeth
In case of rotated teeth the bracket should always be placed more on
side of rotation in the mesiodistal plane . This overcorrected position of
the bracket will result in early correction of the rotation and will also
accommodate the relapse factor after debonding.
A rotated maxillary 2nd
premolar. As the tooth is
distopalatally rotated so the
bracket is placed slightly
more distal than its required
position

Clinical Notes
Sometimes due to severe rotation or
crowding the position of the tooth is
such that it's not possible to place
bracket at the right mesiodistal center
of the tooth

Rotated right upper central incisor. Correct mesiodistal
position of the bracket is not possible on the first bonding
visit due to rotation. The bracket should be
placed as far mesial as possible. The mesial side of the
bracket should not come in contact with left side incisor
because it will hinder the full insertion of the wire and also
make ligature placement extremely difficult if not
impossible

In such situations the bracket should be placed as far as
possible toward the mesiodistal center of the tooth or toward the
rotation. A flexible wire is passed and only the brackets wings
toward the rotation are ligated. At subsequent visit the tooth is
usually derotated enough to place bracket at the right
mesiodistal position
So the bracket is debonded and
either a recycled or new bracket is
rebonded at the correct mesiodistal
position

Clinical Notes
Sometimes the tooth is rotated 180° so that the lingual side is
on the labial side. Many times this form of rotation is
accepted. In such situation the bracket is bonded on the side
of the tooth which is facing labial or buccal .
Right lower lateral is rotated
180°.The
rotation was accepted and
bracket placed on lingual
side of the tooth which was
facing labially

Clinical Notes
Another situation is maxillary lateral incisor substitution by canine. In
this situation the slightly convex labial surface
of canine is made flat to give it shape of lateral incisor and bracket is
bonded at mesiodistal center of reshaped canine
instead of slightly mesial.

Placing the bracket at the mid developmental ridge area
will cause poor contact point with the central incisor as canine is
also reshaped mesiodistally. On premolar tooth which
will become future canine the canine bracket is placed distal to
the mesiodistal center of the tooth.

• It is necessary to position these brackets
gingivally to permit the re-contouring of the
canines required for esthetics and function.
• The orthodontist should place the brackets
according to gingival margin height rather
than incisal edge or cusp tip.

Palatal root torque to
maxillary left canine
Extrusion of maxillary left
canine with 2 boot loops
(butterfly loop); with gradual
removal from incisal tip
Composite buildup on
mesio-incisal angle of
maxillary left canine to
mimic lateral incisor.
Distally positioned bracket on
maxillary left canine
Maxillary left canine extruded.
Note closed boot loops, now
passive.
Bracket repositioned.
Repositioning of the gingival margin by extrusion : Case Report

• 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.
• 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.
• The need for canines extrusion and premolars intrusion to adjust
the gingival level.
• Regarding canines mechanics, special attention should be given to
the torque that the canines should receive, namely lingual root
torque .
Treatment Planning Considerations in Congenitally Missing Maxillary
Lateral Incisor: The Role of Orthodontics (In Orthodontic Aspect)

First premolar bracket bonded more occlusally and canine bracket more gingivally than
usual, producing intrusion and extrusion, respectively, during leveling stage

• However, to improve the interproximal contact points, offset
bonds (in-out) was needed between the central incisor and canine
Occlusal view of Canine Substitution

(A,B) Labial gingival margins were placed at same level as those of
central incisors by progressively increasing archwire intrusion bends
(E,F) Build-up was made with hybrid composite resin
(C,D).using leveling wire in incisal tie-wing area.
Recontouring maxillary first bicuspids to shape, size, and form of
natural cuspids.

• The lingual cusps of the maxillary canines and first
premolars are recontoured to :
1. Eliminate traumatic occlusion of the mandibular lateral
incisors with the lingual surfaces of the canines.
2. Establish a balanced occlusion.

• After the teeth have been aligned and the canines reshaped,
there is frequently a need for restorative treatment to re-create
ideal lateral incisor color and contour.
• This may be accomplished with bleaching, composite resin, or a
porcelain veneer
A, After space closure. Note the unfavorable appearance of both canines
and the traumatically injured right central incisor (arrows).
B, Combination grinding of the canines and composite buildup on the
mesial aspects of the canines and the incisal edge of the central incisor.
Orthodontics Current principles and techniques , (Graber Vanarsdall Vig , 5th edition )

Young boy with bilaterally absent maxillary lateral incisors at start of treatment
Intrusion of canine and extrusion of bicuspid then composite build up of these teeth
Crown torque of “new” lateral incisors and cuspids and marginal gingival levels
of six anterior teeth at end of treatment

Placing the bracket distally will rotate the tooth
mesiopalatally
which increases the mesiodistal width of future canine
tooth, bringing the convex part of the tooth mesial so that
it look
similar to the mid developmental ridge of canine

This position of bracket also helps to hide the palatal cusp of
premolar and improves the occlusal relation with the
mandibular canine. The palatal cusp needs to be grounded to
avoid premature contact with opposing dentition.

Axial or long axis position of the brackets
Axial or long axis position of the bracket is related to the angulation or
tip of the teeth. In conventional edgewise system where there was no
built in tip, the brackets were placed angulated on the tooth. The amount
of bracket
angulation on the tooth was equal to the amount of tip required

Standard edgewise brackets has no built in tip. Bracket
position didn't follow long axis of the crown or root and
were placed angular on the tooth equal to the amount of
tip required.

In preadjusted edgewise system as the tip is already built within
the brackets so placing the bracket similar to standard
edgewise will result in increase or decrease of built in tip. In
preadjusted edgewise system brackets are positioned on the
tooth so that their wings and scribe line are parallel to long axis
of clinical crowns or long axis of the tooth .

A preadjusted bracket of maxillary left
lateral incisor .Placing the bracket parallel to long axis of
clinical crown will cause tooth to rotate in a clockwise direction
and express the builtin tip. C. Bracket placed so that long axis of
the tooth is parallel to long axis of bracket wings and scribe line

But there is always some difference between the angulation
of long axis of the crown and long axis of the tooth in the
mesiodistal plane .
There is always some
difference between long
axis of clinical crown and
long axis of the tooth

Also placing bracket according to long
axis of tooth may result in wrong
mesiodistalposition of bracket on the
crown.

Andrew purposed that as the clinical crown is only visible in
the mouth so the angulation of the tooth should be taken by
taking the angulation of long axis of clinical crown (LACC)
and not the long axis of the entire tooth. But taking only
the long axis of clinical crown may result in poor root
parallelism and in some cases root resorption due to roots
approximation of adjacent tooth

A lateral incisor bracket placed with reference to long axis of
clinical crown. X ray showing that long axis of bracket not
coinciding with long axis of the root
and because of this root of the lateral incisor is in close
contact with central incisor root increasing chances of root
resorption in this area.

So brackets should ideally be placed by taking the clinical
crown as reference but root position should also be kept in
mind. If there are chances of adjacent root resorption by
taking clinical crown as reference then bracket position
should be modified and long axis of the tooth should betaken
as reference.

Taking the long axis of tooth can results in poor
proportions of connectors and embrasures . These
proportions can be corrected at end of treatment
either by composite build up or interproximal
reduction.

A. Golden proportion of connectors that ideally should be
present in finished cases. B .A case with dilacerated central
incisor root. If there is root dilacerations, placing bracket by
following the clinical crown will result
in ideal connector areas but greater chances of root
approximation and so root resorption.

C. Bracket placed by following the long axis of the
roots. The golden proportion of connectors is
distorted. They can be resorted by composite built
up or interproximal stripping at the end of
treatment

Clinical notes
Some clinicians also take incisor edge as
guideline for long axis positioning of brackets. But
incisor edge is mostly uneven due to trauma,
attrition and mamelons. So incisor edge shouldn't
be taken as a reference point for long axis
position of the bracket.

Also gingival zenith(top) shouldn't be
taken as a reference for long axis
position of the bracket as it can be
effected by uneven pattern of gingival
recession

A. Mamelons on central incisors. These mamelons will give a
different long axis position of the tooth if taken as reference for
bracket positioning. B. Attrition of the incisor edge will also effect
long axis position of the teeth. C. Gingival zenith shifted mesial
from their ideal position due to gingival recession. Taking gingival
zenith as reference for axial position of the
bracket in these cases will result in wrong placement of the
brackets

Importance of axial position of brackets
Correct axial position of the bracket is very important for
proper occlusal and esthetic relationship. As preadjusted
brackets have built in tip, a poor axial position of the
bracket will result in expression of increase or decrease
positive or negative tip. Increase in tip may increase space
requirement in the arch and also increase risk of adjacent
root approximation

A&B. Preadjusted brackets not placed in accordance with long axis of
the tooth will result in increase or decrease expression of tip than the
built in tip. C.A x ray showing that both decreased and increased tip of
incisors due
to angular bracket placement. This increases chances of root
approximation and root resorption.

D&E. Over angulated brackets placed on
central incisors can result poor proportion of
connectors and embrasures leading to
development of
black triangles

Change in tooth angulation will also affect the golden
proportions of connectors and embrasures and so the smile
esthetics of the
teeth.

Checking axial position of brackets
The axial position of the brackets is checked under both direct
and indirect vision. Usually maxillary anterior brackets and
mandibular
brackets are checked under direct vision from labial side of
the tooth while maxillary posterior brackets are checked under
indirect vision using diagnostic mouth mirrors.

If there is doubt in position of maxillary anterior brackets
especially lateral incisor brackets some clinicians favor
to use indirect vision by diagnostic mirror and use
guidance from lingual side of tooth.

Modifications in axial position of brackets
Modifications are made in axial position in the
following circumstances
1. To avoid chances of root resorption due to
adjacent root approximation.
2. To avoid root resorption from dental or
orthodontic implants.

3. To avoid root resorption from teeth
impacted in the bones. i-e impacted
canines or mesiodens ..)

Orthodontic implants inserted for intrusion of maxillary
incisor. Note the position of lateral incisors at both ends.
The gingival wings of the brackets are facing distal so they
will rotate both lateral incisor roots toward mesial. Initially
such bracket placement will create space for implant
insertion and during intrusion it will ensure that roots of
lateral remain away from implants.

Once the intrusion is completed and the implants
are removed, bracket position is corrected so that
lateral incisor have optimum angulation

A mesiodens present between roots of the upper central
incisors. Brackets are placed so that wings of the brackets
are facing mesial on gingival side. This will rotate both the
central incisors roots away from mesiodens
and will give good access to surgeons for removing it
without causing any damage to central incisor roots.

The bracket position needs to be corrected
after mesiodens removal otherwise black
triangle will result in central
incisors.

5. In some surgical cases bracket position is modified to
move roots away from surgical site (Wassmound procedure
in maxilla, Subapical osteotomy).
4. To accommodate crown morphology for achieving
golden proportions of connectors and embrasures

6. If teeth have slightly smaller size
such as peg laterals than it is better to
increase the angulation of the teeth
rather then to go for composite build
ups

placement of orthodontic brackets

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