denis krasilnikov

7/29/2019 Denis Krasilnikov

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Denis Krasilnikov

Prof. Mascolo

BIO 211

Invisalign: Clear Braces

A Hollywood smile is a frequent request in a dental office. People desire

straight rows of pearly whites that illuminate a smile. Most individuals, however,

have not been blessed with a perfect set of teeth and turn to Orthodontics for

answers. Prior to resent years metal braces, which were mounted on the teeth for 1-

3 years, were used in order to pull each individual tooth into place. This was not a

popular approach due to the size and discomfort as well as the overall un-appealing

look that metal braces carried with them.

In the late 1990s Zia Chrishti came up with the idea of clear and removable

braces that were to be molded to each individuals teeth. Along with business

partner Kelsey Wirth, Chrishti founded Align Technologyin 1997 and invisalign

braces were created. Invisalign is now used to treat many conditions including

spaced teeth, crowded teeth, overbite, underbite and crossbite.

Invisalign aligners are made of specially designed thermoplastic

material, USP Class VI medical grade, high molecular weight, polyurethane resins,

that appears similar to teeth whitening trays. A series of trays are created in order

to move teeth into their correct position in the sequence determined by the dentist

during the first appointment. To help patients decide if Invisalign is for them, as well

as see the course of treatment, dentist's use a program called Clincheck.


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During the first visit a patient undergoes a "Smile Consulatation" which

determines if the they are to be considered a "candidate" for treatment. In most

cases a patient is eligible if they meet the following criteria: The Patient

Does not have untreated cavities Does not have periodontal (gum) disease Has good oral hygiene habits Is a non-smoker Is committed to treatment and prepared to follow the treatment guidelines

After the consultation qualified individuals are scheduled for a second

appointment during which necessary records are collected. These include full arch

impressions done with ether the iTero/iOC scaner or the traditional PVS impression

as well as x-rays and photos. The iTero/iOC digital scanner is preferred as it creates

more detailed images for better fitting aligners as well as being more pleasant for

the patient than the silicon PVS that must sit on the teeth and has a rather

unpleasant taste, for example "Discus Splash!". These records, along with the

treatment plan created by the dentist, are sent to "Align Technology, Inc." where the

Clincheck movie is produced which determines how many trays will be needed to

align the teeth into their desired position.

Invisalign treatment time varies from patient to patient based on the severity

of the displacement of the teeth and presence of other conditions needing

treatment.
http://www.stroberdental.com/gum-disease-therapy.htmlhttp://www.stroberdental.com/gum-disease-therapy.html


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When talking to patients who are considering using the treatment it has been

observed that many believe the movement of the teeth occurs because the shape

and position matches up with the aligner, which is not the case. Invisalign uses a

biomechanical approach to aligner treatment with the premise being "the correct

force system controls the movement of the tooth". The Foundation of Biomechanics

is that only after figuring out the required forces for desired movement should the

appliance be created. Following this model, clinical outcomes of the aligners have

become much more predictable with the new improvements made by Align

Tecnologies.

These upgrades were introduced under the name Invisalign G3, followed by

the Invisalign G4, and brought with it SmartForce features. A number of inovation

were added to the aligner trays that made Invisalign an option for a wider range of

patients. In some cases the desired tooth movement might be challenging to

facilitate with only the pressure created by the tray. With SmartForce an attachment

is placed on the tooth in order to correctly direct the forces that shall be acting upon

it. These "Optimized Attachments" can be placed on the canines or bicuspids that

need rotation or can be used to improve incisor extrusions.

There is a number of such attachments that can accomplish different effects

due to their placement. With Invisalign G3 came the "Optimized Rotation

Attachment" which is used to rotate any canine or bicuspid. The aligner tray

engages the attachment surface as well as the lingual side of the tooth in order to

deliver the forces and moments required to rotate the tooth about the long axis.


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With the development of Invisalign G4, three new attachments were

introduced. The "Optimized Root Control Attachments" provide greater medial-

distal root -tip control. Forces applied to the two buccal attachments generate a

moment that is desired for root movement. These attachments are available for

upper and lower canines as well as upper incisors and are applicable for space

closure, medial - distal root up righting and treatment of diastima (space between

the incisors).

The 'Multi-Plane Movement Features" were created to improve control of

upper laterals requiring extrusion along with rotation or crown tip. The active

surface of the attachment is oriented to deliver a pushing force while

simultaneously rotating or tipping the lateral. A pressure point on the lingual side

of the aligner is positioned to apply a second force for control of the multi plane

movement. These attachments are applicable to a wide range of lateral movements

and are customized to the patients required tooth movement .

"Optimized Extrusion Attachments" which is a multi tooth approach to open

bite treatment designed for better outcome when a patient has anterior open bites.

The attachments extrude the four upper incisors together using the posterior teeth

as anchorage. Aligner activation levels are now individually adjusted in order for

sufficient extrusive force to be delivered to the incisors to accomplish the desired

movement.

The "Power Ridge" is an aligner feature which has been shaped specifically to

apply "Lingual Root Torque" which is Bucco-Lingual Rotation of the tooth about the

incisal edge. Power Ridges are designed to deliver the correct moment to force ratio


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to achieve incisor torque with lingual root movement where the root of the tooth

shifts in the direction of the tongue. An M/F ratio of 12-13 is enough to accomplish

torque around the incisal edge. Power Ridges and Optimal Attachments cannot be

used together.

While Invisalign is a more physically appealing option than braces it comes

with a higher price. While cost for the original braces ranges from $1500-3000,

Invisalign on average can cost anywhere upward of $5000. The price for treatment

varies with the number of aligner trays required. Usual treatment requires around

14-16 trays. New trays are created every 2-3 weeks in order to move the teeth into

the necessary positions at the rate that the dentist decides.

Invisalign is considered an Orthodontic procedure and in most cases dental

insurances cover 50-60% of all procedure costs. However, despite this being an

Orthodontic procedure, a general dentist can become an Invisalign trained provider

by attending an 8 hour training session costing approximately $2000.

Invisalign is a very popular option among people looking to fix their smile as

it is practically invisible and very effective. No one is ever excited to go into an

Orthodontist's office with the prospect of metal braces in their future. Adults hate

the idea of metal smiles while young children will rarely get excited to show their

friends the new color of elastics they got on their attachments. Now a beautiful smile

is available to everyone without the need to wear a bulky and uncomfortable metal

device on the teeth for a long period of time.


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References

1. Bovenizer, Todd S., D.D.S. "Invisalign FAQs." - Orthodontist Cary, NC.

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2. Sterental, Rene., "Invisalign G4

- Webinar" 07 Oct. 2011.

3. "Required Records." Web

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4. The Science Behind Invisalign. Web. 2012.

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