Clear aligner (Invisalign) therapy was developed in the late 1990s by Align Technologies based on earlier clear plastic appliances. It uses a series of clear, removable aligners to gradually move teeth into the desired position based on a digital treatment plan. Key advantages include esthetics, comfort, oral hygiene, and visualization of the planned tooth movement. Indications include mild malocclusions while contraindications include severe crowding or skeletal issues. Attachments are added to enhance tooth movement. Proper aligner fit is important to achieve the planned results.

1. Clear aligner (Invisalign)
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Dr/ Danilo Aguilar

2. introduction
 Kesling in 1945 introduced the tooth-positioning
appliance
 Henry Nahoum in late 1950‘s developed the vaccum
formed dental contour appliance often termed as the
“invisibles”.
 In 1971, Ponitz of Ann Arbor, Michigan introduced so-
called “invisible” retainers

3. HISTORY
 Zia Chishti and Kelsey Wirth, graduate students in
Stanford University's MBA program.
 Zia Chishti had finished adult treatment with
traditional braces, and wore a clear plastic retainer.
He noticed that if he did not wear his retainer for a
few days, his teeth shifted slightly -- but the plastic
retainer soon moved his teeth back the desired
position.
 Together they started Align Technologies in April 1997
and with the help of a handful of forward thinking
orthodontists, they applied 3-D computer imaging
graphics and created the Invisalign method.

4.  This appliance was the first orthodontic treatment
method to be based solely on three-dimensional (3D)
digital technology.
 Align Technologies received FDA clearance to market
Invisalign in August 1998, and began commercial
operations in July 1999.
 This unique treatment approach allowed both the
orthodontist as well as the patient to develop a visual
understanding of orthodontic tooth movement

5. ADVANTAGES
 Esthetic
 Removable - unlike fixed appliance , one can eat and drink
during treatment
 Comfortable - no metal brackets or wires to cause mouth
irritation
 Better oral hygiene than fixed
 Simplicity of care
 Possible to treat “brittle” perio problems
 No decalcification
 3D control of tooth movement
 Teeth can be bleached with the appliance at the beginning
and during treatment

6. Disadvantage
 •Initially there can be slurred speech
 •Pain from tooth movement during aligner changes
 • Errors with impressions resulting in delayed treatment or mid-
course corrections.
 • Losing the aligners during treatment
 • Results may relapse if proper retainer wear is not followed as
directed by your doctor.
 • Sores and irritation of the soft tissue of the mouth
 • High Cost

7. Indications:-
1. Invisalign has been indicated to be used in adults and adolescents who have
fully erupted permanent dentitions.
2. Indicated for mild non skeletal malocclusions.
3. It was successfully used by Boyd in conjunction with segmental fixed
appliances, or with full fixed appliances used immediately before and after
surgery for certain skeletal Class III malocclusions.
4. Joffe suggested that the Invisalign appliance is most successful for treating
1 to 5 mm of crowding or spacing .
5. Deep overbite problems (e.g., Class II division 2 malocclusions) when the
overbite can be reduced by intrusion or advancement of incisors.
6. Non-skeletally constricted arches that can be expanded with limited tipping
of the teeth

8. Contraindications:-
 Cases contraindicated or which have minimal effect with
this system include:
1. severe crowding and spacing over 5 mm
2. skeletal discrepancy
3. severely rotated teeth (more than 20 degrees)
4. anterior and posterior open bite
5. teeth with short clinical crowns
6. periodontally compromised teeth
7. multiple missing teeth

9. Over view
PVS impressions , waxbite,
radiographs ,photos
CT scan is made impressions
to produce a virtual model
Treat II software used to
simulate the teeth movement
Stereolithography
to build precise molds
of teeth at each stage
Individualized, custom-
created clear aligners are
made from these models
Clincheck allows Orthodontist
to reviews, modify, and approve
the treatment plan.

11. Orthodontic movements which can be produced
effectively
 Space closure
 Tooth movement following IPR
 Dental (not skeletal) expansion,
 Flaring
 Distalization
 Space closure following the extraction of a lower
incisor

12. ATTACHMENTS
 Align Technology defines attachments as three
dimensional shapes added to tooth geometry to enhance
the interaction between an Aligner and the teeth.
 These are represented by the red shapes seen on some
teeth in ClinCheck® that translate into an equivalent
geometry built into the aligner.

13.  The attachments are created by bonding composite on the
target teeth using a special plastic template or the treat-
ment Aligners.
Purpose
• Help in retaining the aligner
• To provide a surface upon which additional force can be exerted
and, in doing so, to create a moment arm for biomechanical
advantage

15. Ellipsoid attachments
 The first attachments were ellipsoid in shape and
looked like a hemisected football bonded to the tooth
surface.
 Ellipsoid attachments are applied when an intrusion,
extrusion, or rotation is intended for the underlying
tooth.

16.  Rectangular curved root tipper (CRT)
attachments
Provide a straight surface against which the aligner can
apply force.
The vertically oriented CRT attachments are most effective
for root tipping and root paralleling, whereas horizontally
oriented ones are most effective for vertical and root torquing
movements.

17. Modifications.
Beveled rectangular (BR) attachments; and
Double horizontal rectangular (DHR) attachments
Inverted T attachments

18. Attachment Protocol
 Align Technology will automatically place attachments
wherever required. One may request attachments for any of
tooth movements by specifying in the special instructions
box of the treatment form or in the comments box in
ClinCheck.

19. Rotation
 The addition of attachments
on the labial or lingual
surfaces (or both) is required
for some teeth to be rotated
 If the rotation is more than
45° fixed appliances may be
employed initially to reduce
the magnitude of the rotation
 Incisors usually rotate more
easily with this appliance
with no need for
attachments.

20. Anterior Intrusion
For intrusions, the attachments add retention of the
appliance on the teeth adjacent to the tooth to be intruded.

21. Anterior Extrusion
 Extrusion has proven to be one
of the most difficult movements
to achieve with this appliance.
 Aligner must completely cover
attachment and have 2 mm
space gingival to attachment
with aligner well adapted
 Extrude teeth with an elastic
from a button on facial of tooth
and lingual of aligner
 Must have slight interproximal
space check with floss
(stripping as necessary)

22. Lower Incisor
Extractions
Bicuspid Extractions

23. Class II occlusion correction with Invisalign
 Consider intra-arch
movement using other teeth
as anchorage to achieve
inter-arch corrections
(i.e.,distalization of molars in
a class II)
 It is also possible to place
inter-arch elastics on
aligners by cementing hooks
to aligners (purchase kit
from AlignTech) to correct
mild A-P problems but
retention of aligners when
wearing elastics is a limiting
factor.

24. Correction of Midline Discrepancy
 Midlines can be corrected by asymmetric Class II
and Class III elastics attached to the teeth on clear
buttons.

25. Aligner fit
 The aligner must fully “cup” the tooth crown at all
times to prevent the occurrence of aligner length/arch
length discrepancy
 If there is a problem with the aligner fit, then the
shortened aligner will force the teeth into segmental
crowding. The ill-fitting short aligner will apply
significant force (as the patient bites into the tray to
seat it better) at the distal of the terminal molar.

27.  Thus, it should be
understood that poor
vertical fit of the aligner
promotes mesio-distal
problems
 The aligner can fully seated
with the help of Chewies
made of polyurethane foam.

28. Retention
 Usually, the final appliance or a thicker version - 0.04
inch ie (Exceed-40 (EX40) of it, is worn full-time for 6
months.
 It is seen that more than 85% of patients have posterior
bite.
 To close posterior bite cut aligners distal to occlusal
contacts (usually 1st or 2nd premolars) and let settle 2-4
week
 This is followed by nighttime wear indefinitely.

29. WHY INVISALIGN
 Increased awareness for esthetics
 Patients are more aware of plaque associated
problems with fixed appliances
 Many patients do not want fixed appliances
(especially adult and re-treatments)
 Appreciation of the benefits of technology (especially
teenagers and young adults) . Most orthodontic
patients are computer literate and appreciate how
technology can enhance treatment
 Invisalign website generates many referrals
 Alternatives to porcelain veneers

30. Thank you