Search Results for: attachments

Why do so Many Struggle with Invisalign’s Optimizations?

I frequently hear orthodontists lamenting the advent of Invisalign’s optimized attachments. I think this frustration stems from several factors all of which result from an inadequate understanding what these optimizations are and how they are meant to function. To think of optimized attachments as simply little bumps on teeth made for pushing is the fundamental misconception. As opposed to conventional attachments, which are simply crude handles, optimized attachments (and features) have moved away from the old approach focused only on changing the shape of the tooth and are almost entirely reliant upon aligner forming elements in order to produce customized force systems based on the prescribed movements.

This dramatic shift in thinking has been driven by the huge piles of treatment data gathered by Invisalign, free from the observational bias of the individual. Failure to acknowledge data-driven optimizations and attachment design is simply not science based and utilizes Invisalign as an inferior product so it is important that you able to keep pace with the current best practices. We will spend some time helping you treat your patients more efficiently with Invisalign by briefly examining the Top 7 sources of operator error with Invisalign’s aligner optimizations.

The rest of this post is available only to orthodontists and orthodontic residents registered with the Ortho Cosmos

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Attachment Selection and Design

Attachments serve several purposes in aligner therapy. The most basic function is retention. In order to fully express prescribed movements, the aligners have to be fully seated. Aligners have a flexibility that needs to be compensated when seated onto arches that require movement. The second function of attachments is to facilitate movement by changing the shape of the tooth to provide an active surface for pushing.

The active surface of the optimized attachment is oriented to deliver the desired forces while simultaneously extruding, rotating or providing root control. Each attachment has a specific surface where the aligner provides that pressure, while the non-active surface is relieved to avoid any interference.

When it comes to Invisalign treatment, the use of attachments is an important step to achieving the best results. But what attachment is the most effective for the desired movement? That answer depends on the desired function of the attachment, and the type of movement planned.

For retention, conventional attachments are very effective. Greater retention can be achieved by increasing the size of the attachment from 3 mm to 4 mm or 5 mm width. Retention provides anchorage and also locks the aligner better when using inter-arch elastics.

For active movements, optimized attachments have been designed by data-driven analysis. These attachments are customized by Align Technology’s software to deliver specific force systems. They are added when the intended movement meets a certain threshold. When these attachments match the desired force system, they are the recommended selection when you are considering traditional attachments vs. aligner optimization.  Some movements do not meet the criteria to generate an optimized design. This is where modifications to conventional attachments can be made to approximate the designs of optimized attachments normally selected for the desired movements. Using 3D controls, the position and amount of bevel can be adjusted to match a similar, optimized design.

Common Sense Invisalign Mechanics

I always get a good chuckle when I hear ‘flat-earthers’ proclaim things like “optimized attachments don’t work.” This position is anti-science, and ironically sounds a lot like the now completely debunked claim that “Invisalign doesn’t work.”

The old mindset of Invisalign treatment was to deliver the desired forces by modifying the shape of teeth with attachments, creating nothing more than a crude handle to push on. The solution then to any bio-mechanical problem was to add more attachments and/or bigger attachments based on a visual inspection of the apparent force vectors. However, it should be common knowledge to any trained orthodontist that a visual method of determining forces, while seemingly obvious, leads to faulty conclusions and frustration. Unfortunately, many people still approach Invisalign bio-mechanics in this way.

Data-Driven Force Systems

Invisalign’ s optimized attachments and optimized force systems, like SmartStage, do not function in nearly the same manner as traditional attachments. Instead of just a handle, Invisalign’s optimized element use unique aligner-forming features and pre-activated attachments to deliver custom force systems based on individually prescribed tooth movements. As a result, smaller attachments can be utilized and less teeth require attachments. This technology would not be possible without Align’s extensive treatment databases, which allow for aligner bio-mechanics to be better examined on a massive scale and without visual bias.

Data-driven force systems, developed by data analysis of thousands of cases using well controlled selection criteria, will always trump the arbitrary conclusions made by any one person and the comparatively small sample size they have to draw on. If you use Google as your search engine, you already know that big data makes all the difference.

As a speaker for Invisalign, it would be convenient for me to turn attachment selection into a mysterious process where I alone am in possession of “secret knowledge” that has been denied to everyone else, but that is not how science works. Continuing to promote the use of traditional attachments when an optimized solution exists is simply not science based, and advocating the use of an inferior clear aligner product.

Orthodontists’ personal struggles with optimized attachments are simply the result of inadequate clinical systems for attachment placement and a failure to seat key aligner forming features during treatment. This seems to occur regardless of experience level.

Without consistent seating of aligner features throughout treatment the optimized attachments cannot not deliver the prescribed forces. You can see what I am talking about with regards to poor placement in the diagram below.

The Importance of a Skilled Orthodontist

With Invisalign’s algorithms helping orthodontists to provide more efficient force application, we are freer to design better smiles and better bites for our patients. It still takes a significant amount of input from a skilled orthodontist to properly plan optimal movements and the final alignment if you are going to deliver the best outcomes for your patients. However, when it comes to attachment planning, our role is now to audible between optimized approaches rather than being forced to design attachments from the ground up.

SmartForce Optimization Features

Effective utilization of Invisalign’s optimized attachments and features depends on a number of factors, not least of which is proper selection from the optimized attachment hierarchy. However, to be able to leverage the attachment hierarchy efficiently the orthodontist must first understand the various manufacturing thresholds for optimizations.

We have laid out all the SmartForce Optimized Attachments and Aligner Features in the table below so that you can determine which combinations of optimized features have been triggered by your prescribed treatments.

The rest of this post is available only to orthodontists and orthodontic residents registered with the Ortho Cosmos

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Interceptive Aligner Therapy

Why would an orthodontist or an orthodontic patient consider treatment with clear aligners in the mixed dentition? My thoughts center around the same premise why adults and teens are offered aligner therapy: for a more comfortable patient experience. While the orthodontic world is full of appliances used for Phase I treatment, aligner therapy is finding a place in this age. Invisalign is already in the process of tailoring their product to function more seamlessly for interceptive treatment, but the extended refinement period on approved cases has opened the doors for most practices to start offering this option.

Considerations

For any of you considering integrating aligners into a Phase I treatment plan, you should take into account a few factors that will make your experience, as well as the patients, the most positive it can be. First being the purpose and objectives of your Phase I treatment. Since patients are often in the early mixed dentition, the treatment should be focused on the limited goals. Ordering several sets of additional aligners can easily prolong treatment when managing erupting teeth. Keep the goals and limits very clear to avoid getting sucked into multiple and excessive refinements.

Clinical Crowns

Second, the clinical crowns in the mixed dentition are short, so beware. Short clinical crowns in aligner treatment can spell fit and retention issues, if not managed properly. To address this challenge, add many more of attachments for retention. I add attachments on the primary molars and try to avoid the primary canines since their loosening can cause issues with fit.

Tooth Eruption

Third, beware of erupting teeth. We have had a few patients where we scanned and by the time the aligners came, they wouldn’t fit! Whenever possible, I have been more selective with cases that are in a less transient mixed dentition where the four incisors have erupted and you have several months before any more primary teeth erupt. Remember that eruption tabs are quite specific and more designed for late mixed dentition cases. When incisors have not erupted, or even first premolars, I find I was chasing the case until I could scan again and again. Therefore, be selective in timing of cases.  Also be creative using pontics where eruption tabs are not available.  The advantage of the developing and erupting dentition, is that once space is opened, teeth will erupt into place and commonly drift into pontic spaces or eruption tabs.  These are advantages in an aligner system, compared to the obstruction brackets bonded on exfoliating primary teeth.

Phase I Features

There are also some additional features in the pipeline that are well suited for early treatment.  These include pending features such as a Phase I aligner product, an expansion appliance in the works, and the MFA appliance that will facilitate Class II correction.

Despite some potential challenges, and many young patients requesting colors for treatment, proper case selection in Phase I aligner cases can lead to success.  Aligners for young patients can offer another great option that was not available before.  Knowing these potential challenges and proper preparation for these treatment plans can offer the same advantages teens and adults experience while in the early mixed dentition.

Et monuit

Extraction treatment with aligners is possible and can be effective, but be warned. I regularly warn doctors that more complex treatment plans with aligners do need a minimum level of proficiency. The reason being, that anyone can finish a successful case. The true measure of your skill is how you recover from a case that doesn’t go “by the book”.

Warnings aside, we all will encounter patients that will insist on aligner therapy where an extraction treatment plan is indicated. Some of you like a challenge like I do, and may elect to treat select cases with this technique. I can appreciate that when done properly, cases with extraction treatment can be predictable and a positive experience for both the orthodontic practice and patient.

It’s a different skill

I know many orthodontists who use aligner therapy regularly, who do not do extraction treatment with Invisalign. Depending on your patient demographics, you may never feel the need to use this technique. If you are pulling punches on teen cases, Class I, Class II, deep bites, etc, just stay away. It’s really not funny to see doctors who have treated very few cases jump into aligner extraction treatment. Sometimes they get lucky, but often I see an orthodontist leave with a bad taste for aligner therapy when there are plenty of opportunities to treat other types of cases. Sometimes, you don’t know what you don’t know.

Diagnosis, diagnosis, diagnosis

Are you sure it’s an extraction case? Unlike fixed appliances that expand and procline, Invisalign is a closed system that has to be intentionally designed to procline and expand. From my experience, it’s strength is in retraction and constriction. IPR, expansion, distalization, etc. are tools available in an aligner system if integrated to address various crowding issues.

Measure twice, cut once

Use Clincheck as the diagnostic tool it is designed to be. I enjoy how a patient can be run through various treatment scenarios before even starting to move a single tooth. This is a powerful tool often overlooked. You don’t have to guess, simply setup various plans and see how the outcomes change. Then select the treatment plan that best matches your treatment objectives.

Setup for success

Extraction treatment often caters to the mastery of all 3 dimensions with an aligner system. The most predictable extraction cases present with severe crowding where tipping teeth into the extraction sites leads to a great outcome. Some cases are more challenging when a deep bite is present and when root movements are necessary. Often, the most challenging cases present as bimaxillary protrusion with little to no crowding.

Some of the considerations when planning extraction cases include objectives in anchorage, root control, attachment design, staging, incisor root torque, curve of Spee and AP changes. It is important to control the roots of the canines, bicuspids and molars. Add significant attachments on canines, bicuspids and molars with maximum length from occlusal to gingival, or better yet, optimized designs.

Consider the anchorage in each case (mild, moderate or maximum). G6 protocols should never be used when any mesial movement of the posterior teeth is incorporated and is only effective in maximum anchorage cases. Significant mesial movement of posterior teeth may also require attachment on second molars and more hefty attachments on the first molars.

Don’t jump without a parachute

Especially if you don’t have many cases under your belt. Seek mentorship, learn from all the CE that is available at lectures and online. Don’t forget as  orthodontists there are many tools at our disposal. Inform patients that finishing with fixed appliances is a possibility. It is best to warn than to give excuses.

The patient demand for aligner therapy has grown over the years, and yet the challenge as orthodontists has been proper case selection and learning what types of patients can be treated with Invisalign. Every appliance we use has limitations, and aligners are no different. The opportunity we have is that technology has advanced the effectiveness of aligner therapy and increased the range of treatable malocclusions from Class I crowding to a range of problems that were once thought to be unachievable.

There are many perceived aligner therapy limitations.  Let’s review some of those areas that are commonly perceived as beyond the reach of aligners, and review a few Invisalign treatments that addressed these malocclusions:

Significant AP Correction

Deep Overbite

Anterior Openbite

Significant Root Movement

Bicuspid Extraction Therapy

There is a common misconception amongst the public and the orthodontic specialty that orthodontists are in the business of braces and wire bending. As patient demand shifts to expecting the same results from orthodontists but in more convenient and comfortable modes of treatment, it is important for us to remember that we are not in the braces business. Our specialty should continue to focus on the results we want to provide patients, and continue to explore modalities that fit into the experience patients desire. Properly implementing aligner therapy into an orthodontic practice does not have to compromise on these expectations.