The science of

the Invisalign system

®
Advancing treatment innovations
for more predictable outcomes.
Evolution of Invisalign® World-class
clinical innovations technology innovation
The Invisalign system is the worldwide market leader and most The Invisalign ® system is the most technically advanced clear
recognised brand in clear aligners. aligner system in the world.
In 1999, Align Technology pioneered the invisible orthodontics market with the introduction of the Invisalign system. Align These innovations are clinically proven to work together to deliver excellent treatment outcomes by creating the right
Technology is committed to continuing innovation in its products and to helping Invisalign providers treat with confidence – force system to achieve tooth alignment. Align Technology continually invests in R&D, which has resulted in a steady
achieving practice success through successful outcomes. cadence of significant product evolutions for Invisalign clear aligners.

Invisalign innovation milestones.

Automated Biomechanics Materials 3D design & Data analytics Intraoral iTero

Root torque 1 st premolar extraction treatment planning modelling machine learning scanning
& manufacturing

Extrusion SmartTrack material Power arms Mandibular advancement

for Class II correction
We have developed three technologies over 20 years, for better
2009 2013 2015 2017 predictability and outcomes.
1.5 release SmartTrack Invisalign G6 Mandibular advancement

Precise control Aligner shapes to execute

2011 2014 2016 Patented material
of movement orthodontic movement
Invisalign G3 Invisalign G4 Invisalign G5 Invisalign G7

Rotation Root control Precision bite ramps Shorter treatment time SmartTrack ® material SmartForce ® features SmartStage™ technology

Specially designed aligner Attachments and features Advanced algorithms that

material provides gentle, more engineered to deliver the force generate the optimal path of
Multiple tooth Multi-plane Aligner pressure constant forces to improve systems necessary to achieve tooth movement and aligner
extrusion attachments areas for intrusion
control of tooth movements predictable tooth movements shape for greater predictability

Open bite
How the Invisalign® system works Root
M Lingual root torque
The Power Ridge feature is a change in the shape of the aligner designed
Centre of to apply a lingual force to the tooth and to control the distortion of the
Resistance
The Invisalign system, designed based on orthodontic aligner near the lingual incisal edge. Treatments for lingual root torque with
retraction result in removal of the contact on the lingual incisal edge that is
principles and forces, is clinically proven to achieve more Crown Power required for control of the root; the lingual Power Ridge feature is designed
predictable clinical results. Aligner
Ridge
feature to restore the contacts in these treatments.

Fig 2. The Power Ridge feature applies lingual force

to the tooth.

A major advancement in aligner treatment has been determining the optimal force system
to move the tooth along a compound pathway comprising many movements, and then
determining the combination of features required to produce the force system necessary Long axis Extrusion
for this movement. Features of the Invisalign System are developed on principles of An Optimised Attachment changes the shape of the tooth so forces can
biomechanics and advanced simulation to better control tooth movement for optimised be applied in the correct direction. The Optimised Extrusion Attachment
treatment outcomes. SmartTrack material combined with SmartForce features and Aligner provides a flat planar “active surface”, on which the aligner imparts force. It is
SmartStage technology allows more predictable tooth movement, which is unmatched force the only surface engaged by the aligner. The rest of the attachment material
by any other clear aligner system. exists only to hold the active surface in place.
Lingual
Control of the direction and magnitude of force is essential to provide
Extrusive force accurate force systems and to control tooth movements.
Fig 3. Optimised Extrusion Attachment,
delivering an aligner force on the flat planar surface When extrusion of all four incisors is required, the Multi-tooth Anterior
with components that are extrusive and lingual.
Extrusion Attachments ensure that a nearly equivalent force is delivered
to each tooth. This force system is considered to provide more successful
extrusion of all incisors as a unit and is being used effectively in the treatment
of open bite.
M The Invisalign system is force-driven
Fig 4. The Multi-tooth Anterior Extrusion
Root The Invisalign aligner, created using a force-driven system, is formed in a shape attachments, designed to extrude all four incisors.

that is intended to impart specific forces to the tooth crown, resulting in the
desired tooth movement.
F1
A moment is the tendency of a force to produce a rotational movement of the
Crown tooth, including angulation and inclination. The proportion of the moment to the Rotation
F2 force is termed the moment-to-force ratio (M/F), which controls the centre of
Rotation of a tooth around its long axis, considered difficult to achieve with
rotation of a tooth. By applying a range of M/F values, different types of tooth
Fig 1. It is necessary to control the force system for aligners, has been improved using a fundamental biomechanical approach.
the movement of both the root and the crown for movement can be accomplished.
excellent orthodontic treatment.
Fig 5. Rotation of canines and premolars More predictable rotation of canines and premolars can be accomplished
using the Optimised Rotation Attachment.
Force systems are measurable. Invisalign aligners are designed with precise using Optimised Rotation Attachments.
control of the force system to provide excellent control of tooth movement.
The active surface of the attachment is automatically positioned on the buccal
Unlike displacement-driven systems used by competitors, the Invisalign aligner surface, as far from the long axis of the tooth as possible and designs the
treatment has provided improved control of the M/F ratio, resulting in improved Fig 6. Control of root angulation and alignment. A
aligner to apply force to this surface. The result is a substantial moment of the
change in angulation requires a mesial or distal force force to rotate the tooth in the desired direction.
control of the root movement with respect to the crown. and a second order moment. The aligner is designed
to produce a force on the gingival attachment in
the direction of movement of the root. A second
attachment placed occlusally provides the counter-
moment necessary to control root movement.
 SmartTrack® material SmartForce® features
Designed exclusively for the Invisalign® system to deliver the optimal Software-driven attachments for simple to complex movements.
force systems to provide greater predictability of tooth movement. The Invisalign® system is the only clear aligner system
that combines multiple Smart innovations. It is designed
• Patented, proprietary, multi-layer SmartTrack material is specifically for treatment of more difficult malocclusions
clinically proven to improve tooth movement and performs such as open bite, deep bite or first premolar extraction
better than materials used by competitors. (planned for maximum anchorage).

• Aligners made from SmartTrack material provide better fit, Proprietary ClinCheck® treatment planning
better comfort and are easier to insert and remove than software analyses tooth movements to determine
aligners made from off-the-shelf, single layer 0.030in material. the optimal force system required and automatically
• Unlike most competitor products, Invisalign delivers a truly places attachments and features to achieve the
custom fit for your patients with aligners trimmed to each desired movement based on specific tooth size and
patient’s unique gum line for better aesthetics and fit. shape. Required tooth movement is not determined
manually by lab technicians.

Gentle constant force High elasticity Excellent aligner fit

SmartTrack delivers a lower initial When the aligner is stretched, the highly A highly formable aligner material can
insertion force for improved patient elastic SmartTrack returns more closely be thermoformed to more precisely
comfort, while maintaining a gentle, to the programmed aligner shape, which conform to tooth morphology,
more constant force over a 2-week helps to improve tracking. attachments and interproximal spaces.
aligner wear period to improve tracking.
What about aligner products that don’t
use attachments at all?
14-day aligner stress relaxation Elasticity Blue gel test Angle Orthodontics Study Conclusions
Standard aligner material
A three-dimensional FE analysis of a plastic aligner system found
SmartTrack that biomechanically supplementary composite attachments
Stretched
generate the force system required to produce bodily tooth
FORCE

Standard aligner material

movement; the absence of biomechanically supplementary

TIME DAY 7 DAY 14 SmartTrack
Previous composite attachments favours the undesired inclination
aligner material SmartTrack
Force measured in simulated oral environment
(100% RH @ 37 degrees C). (Data on file at Align
Stretched of the tooth during translation movements.
Technology, Inc.)
Blue impression gel is injected into
the aligners to indicate the intimacy of
aligner contact with the teeth. White
areas indicate close contact while
blue areas indicate a gap in contact.
SmartForce features and attachment protocols ® 1

Feature Movement Available on Visual Threshold1 Maximum Velocity

SmartForce Features

Buccal Power Ridge Lingual root torque Upper and lower incisors 3o of torque 1o / stage

Buccal Power Ridge +

Lingual root torque and retraction Upper incisors 3o of torque, and retraction 1o / stage
Lingual Power Ridge

0.5 mm of extrusion of the

Multi-tooth Anterior Extrusion Extrusion Upper incisors 0.25 mm / stage
four incisors

Optimised Multi-plane Extrusion ± crown tipping Absolute extrusion 0.1 mm AND crown tipping and/or
Movement Features ± rotation ± intrusion
Upper and lower incisors
rotation 5o and intrusion or extrusion
–
Pressure
area

Pressure Areas Anterior Intrusion Incisors and lower canines aligner

0.5 mm intrusion 0.25 mm / stage
resultant force
force

Precision Bite Ramps (are not SmartForce features

per se, but can be prescribed by the Provider, and are placed Disocclude the posterior teeth Upper incisors – –
depending on compatibility with other features)

SmartForce Attachments

Upper and lower canines and

Optimised Rotation Attachment Rotation 5o of rotation 2o / stage
premolars

Optimised Extrusion Attachment Extrusion Upper and lower incisors and canines 0.5 mm of extrusion 0.25 mm / stage

• Upper central and lateral incisors • 0.75 mm for central and lateral incisors
Optimised Root
Tipping • Upper and lower canines and • 0.75 mm translations from the centre of resistance for 0.25 mm / stage
Control Attachment
premolars canines and premolars

During anterior intrusion, Deep Bite

Deep Bite Attachments Attachments are used for anchorage/ Upper and lower premolars When anterior intrusion is planned –
retention or activated for premolar extrusion

Optimised Retraction
Canine retraction Upper and lower canines Canine retraction
Attachment
Multi-tooth Unit 0.25 mm / stage
Note: variation in type of
Optimised Anchorage Upper and lower second premolars attachment, or variation of
Posterior anchorage attachment placement can occur Posterior anchorage
Attachment and molars for short crowns.

1 mm or more intrusion adjacent upper 1 mm or more intrusion on either adjacent

Optimised Support Attachment Upper lateral incisors 0.25 mm / stage
centrals or upper canines canine or central incisor

When incisor retraction

Optimised Anchorage Attachment – is planned
1 mm of incisor retraction –

1. The default protocols described in this document are used to create the initial ClinCheck® treatment plan, based on the Invisalign Provider’s prescription. However, the final treatment plan remains
the responsibility of the Invisalign Provider and should be reviewed carefully and modified as necessary before the ClinCheck treatment plan is approved.
SmartStage™ technology Power of innovation
Designed to optimise tooth movement for greater predictability. Invisalign® G7 for enhanced finishing.
Proprietory SmartStage technology is an advanced algorithm that determines the optimal path* of tooth movement Invisalign G7 represents the next set of features engineered to improve finishing and is powered by SmartStage™ technology.
and the shape of the aligner † at every stage of treatment. It helps to generate the desired force systems necessary
for more predictable treatment outcomes.

F F Optimised Multiplane Attachments allow better tracking of upper

How does SmartStage technology work for Invisalign G6 First ® laterals when rotation with extrusion or intrusion is planned.

Premolar Extraction solution?

Invisalign G6 First Premolar Extraction treatment with maximum anchorage is engineered to achieve vertical control and
parallelism with predictable outcomes.
Optimised Support Attachments
on upper lateral incisors are engineered to deliver improved tracking
of upper laterals when neighbouring teeth are intruding.
SmartForce ® features SmartStage technology
• O ptimised Retraction Attachments  ligner Activations‡ are programmed to
•A
are designed to allow effective bodily eliminate both unwanted tipping and anterior
movement during canine retraction extrusion during retraction. Optimised SmartStage Root Control enables mesial distal
root control for premolars with only one attachment.
(with or without elastics) when used •T
 he aligner shape is changed at the specific
with SmartStage technology. location where it contacts the attachment
• O ptimised Anchorage Attachments active surface. Different changes in the
are designed to work with shape of the aligner, termed “activation”,
SmartStage technology to maximise apply different force systems, resulting
posterior anchorage. in different tooth movements.
Shorter treatment time with weekly aligner change.

Only Invisalign clear aligners have three critical technologies that allow them to work in fundamentally different ways.
Placing a greater M/F ratio on the posterior teeth than These innovations are clinically proven to work together to deliver excellent treatment outcomes by creating the right force
on the anterior teeth maximises anchorage. systems to achieve tooth alignment:

• SmartForce® features allow for treatment of more complex cases through optimised control of both the root and crown.
The default staging protocol is 1/3 canine retraction
followed by simultaneous staging. • SmartTrack® material, designed solely for the Invisalign system, delivers a low, more constant force for greater clinical
predictability and improved patient comfort.
More aligner activations are applied to counter the
• SmartStage technology is an advanced algorithm that determines the optimal path of tooth movement and the shape of
extrusion and loss of inclination anticipated when closing Optimised Optimised Aligner
Anchorage Attachments Retraction Attachments Activations the aligner at every stage of treatment.
a first premolar extraction site and maximum anchorage
is desired. Weekly aligner changes may reduce treatment time up to 50% compared to two-week changes.

* The optimal path of tooth movement is determined by the progression of movements in the aligner.
† The shape of the aligner at each stage is determined by aligner activations.
‡ Aligner activations with SmartStage technology are not visible in the ClinCheck treatment plan but are automatically built into the aligners.
Invisalign® treatment with
mandibular advancement Clinical evidence
A simple, efficient, patient-friendly choice for Class II correction. Over 4.7 million Invisalign ® patients treated globally, including
Invisalign treatment with mandibular advancement is a single appliance solution for Class II correction in growing over 350,000 patients in Asia.
patients with retrognathic mandibles.
Since 2011, over 900,000 patients with complex malocclusions have been treated with Invisalign clear aligners;
including Class II, open bite, premolar extraction and deep bite

Over 688,000 Over 134,000

moderate to severe deep bite patients Class II patients

A pair of buccally placed, reinforced precision wings are integrated into the aligners so that as the patient bites down
and forward, the precision wings will engage and hold the mandible in an advanced position, while simultaneously
aligning and levelling the teeth without elastics or functional appliances. The wings are positioned between the first
molars and premolars, and are made of the same proprietary SmartTrack ® material as Invisalign aligners.

Case compliments of Glaser Orthodontics Case compliments of Brodsky Orthodontics

Raised
Class II correction
Simultaneously gingival cutline
achieved in single
aligns and levels. improves
or multiple jumps.
patient comfort.
Over 122,000 Over 78,000
open bite patients first premolar extraction patients

Improved eruption compensation

Proprietary eruption compensation algorithm enables Together with the existing eruption compensation features
highly accurate* space-holding for canines and second for first premolars and terminal molars, doctors have a more
molars to naturally erupt into the aligners. complete set of tools for use with late-mixed dentition cases.
Case compliments of Gersch Orthodontics Case compliments of Swiss Smile Schweiz AG
• Leverages either the contralateral tooth or draws from an
extensive tooth library to determine the space to hold for
the erupting tooth.

• Uses improved placing rules to set vertical location to

occlusal plane.

Resolution of the digital approach is 0.1 mm for mesial-distal width and buccal-lingual width in the digital tooth library, compared with 0.5 mm with visual-estimation from X-ray. All materials and images are for illustrative and educational purposes only.
* Int J Oral Maxillofac Implants, 1994; 9:455-60.
Doctor testimonials Attachment material summary 1

The Invisalign ® brand is the most recognised brand in orthodontics. SmartForce ® features direct and deliver the biomechanical forces
needed for orthodontic movement with Invisalign® treatment.
These composite materials and compatible bonding adhesives were bench-tested by Align Technology, Inc. in 2015
and met performance criteria for accuracy, wear resistance and bond strength.

Composite Composite Composite Bonding Adhesive

“A few years ago, we would only treat simple spacing or crowding cases in our Composite Type
Material2 Manufacturer Adhesive3 Manufacturer
teen patients with Invisalign clear aligners. Today, we feel very comfortable
treating many types of malocclusions, including Class II and Class III cases. We Venus® Diamond Heraeus-Kulzer iBOND® Total Etch Heraeus-Kulzer
have even treated a number of extraction cases successfully with Invisalign
clear aligners. The 3D controls have been one of our favourite innovations,
Grandio® SO VOCO GmBH Futurabond® U VOCO GmBH
allowing us to place the attachments exactly where we want them. The
improved attachment designs have made treatments very predictable and help
ensure that our patients stay on track.˝ Venus® Pearl Heraeus-Kulzer iBOND® Total Etch Heraeus-Kulzer

Doctor Charles L. Gemmi III,

DMD Partner, Packable SonicFill™ Kerr Dental Optibond™ XTR Kerr Dental
Orthodontics Limited, USA

Tetric EvoCeram® Ivoclar Vivadent G-ænial™ Bond GC America

3M Filtek™ Supreme 3M Adper™

3M ESPE 3M ESPE
Plus Prompt L-Pop

3M Adper™
3M Filtek™ Z250 3M ESPE 3M ESPE
“In Asia, many patients require treatment of severe crowding and bimaxillary Prompt L-Pop
protrusion. When I heard that Invisalign G6 Solution is designed to treat
extraction of first premolars, I was very excited as I learnt their innovation is based G-ænial™ Universal Flo GC America G-ænial™ Bond GC America
on extensive research and development, and also doctors’ feedback. I’m pleased
that we have a product like Invisalign G6 in the market and believe the innovation
Tetric EvoFlow® Ivoclar Vivadent G-ænial™ Bond GC America
would be of great help not just to patients in China, but also the entire Asia, in
which more than 50% of the orthodontic treatments require extractions.˝ Flowable 4

Grandio® SO
VOCO GmBH Futurabond® U VOCO GmBH
Professor Zhou Yanheng Heavy Flow
Former Chairman of China Orthodontic Society
Filtek™ Supreme Scotchbond™
Vice President of Asian-Pacific Orthodontic Society 3M ESPE 3M ESPE
Founder and Managing Director of Sunny Dental Group Ultra Flowable Universal Adhesive
Invisalign Advisory Board Member in APAC
1. Availability of these materials are subject to regulatory approvals in specific markets. 2. Material selection and use shall be determined solely by the Doctor based on evaluation of each individual
patient. 3. Bonding adhesives were considered compatible with the corresponding dental composite per the manufacturer’s recommendation. 4. All flowable composite materials require careful
handling to avoid air bubble formation, which negatively affects the integrity of attachment.
 The Invisalign ® system :

is the most technically advanced clear aligner system in the world.

is designed on orthodontic principles and forces, and is clinically proven to achieve

more predictable results.

$1 Billion
investment in R&D
879
patents worldwide
4.7M+
patients

© 2017 Align Technology Inc. All Rights Reserved.

INVISALIGN ITERO and CLINCHECK, among others, are trademarks and/or service marks of Align Technology, Inc. or one of its
subsidiaries or affi liated companies and may be registered in the U.S. and/or other countries.